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USHIMARU AtushiGraduate School of Human Development and Environment / Department of Human Environmental ScienceProfessor
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■ Paper- Elsevier BV, Sep. 2025, Landscape and Urban Planning, 261, 105377 - 105377, English[Refereed]Scientific journal
- Abstract The persistence of angiosperm communities largely depends on pollinator‐mediated interactions. However, the importance of plant–pollinator interactions has often been overlooked in studies of plant community assembly. This study aims to assess the influence of plant–pollinator interactions on the assembly of plant communities. We compared the distribution of three floral traits (colour, symmetry, and tube length) across approximately 650 animal‐pollinated plant species in six plant communities located in distinct geographical regions: Mongolian grassland, Japanese grassland, Japanese alpine zone, Swedish subalpine zone, Swedish alpine zone, and New Zealand alpine zone. Additionally, we examined the pollinator fauna in each community, focusing on the taxon‐specific usage of floral traits by pollinators. The composition of all floral traits was predictably linked to taxonomic composition of the pollinator fauna and taxon‐specific preferences of pollinators for certain floral traits. Furthermore, the dispersion of floral morphology depends on composition of pollinator fauna, rather than phylogenetic dispersion of plant communities. Interestingly, while composition of flower symmetry was largely linked to plant family composition, compositions of flower colour and tube length were almost independent of plant family composition. Our study suggests that pollinator fauna influences the assembly of floral traits. Analysis considering plant family composition suggests that the assembly process could be either ecological, where plant–pollinator interactions select for specific functional traits from a pre‐existing pool, or evolutionary, where traits evolve in response to the pollinator environment within a community. This highlights the dual pathways through which pollinator fauna influences plant community assemblages.Wiley, Apr. 2025, Plant Biology, English[Refereed]Scientific journal
- Elsevier BV, Apr. 2025, Agriculture, Ecosystems & Environment, 381, 109437 - 109437, English[Refereed]Scientific journal
- Abstract Aeginetia indica (Orobanchaceae) is a parasitic plant of Miscanthus sinensis with large, red‐purple, tube‐shaped flowers, though its pollinators remain unknown. Common bees may not visit its flowers under the shade of M. sinensis. We identified flower visitors of A. indica through interval photography and direct capture. All 14 photographed visitors, except for one, and 16 captured visitors were Ceratina bees (Apidae), mostly female C. flavipes. Pollen of A. indica (100–10 000 particles) was found only on the body of female C. flavipes, suggesting that they are the sole pollinators of A. indica. Ceratina flavipes is known to nest inside the stem of M. sinensis. Such a pollination system, “a mutual relationship between parasitic plants and insects inhabiting the same host plant,” has not been documented previously. The use of insects that inhabit the same host plants as pollinators appears to be a reasonable strategy and may also be found in other parasitic plants.Wiley, Mar. 2025, Plant Species Biology, English[Refereed]Scientific journal
- Abstract Grasslands face rapid decline worldwide. Among the main threats to these ecosystems are changes in land use, such as abandonment and forestation, which promote forest vegetation to the detriment of grassland plant diversity. To support the conservation and restoration of grasslands, it is key to understand what ecological processes limit the recovery of their biodiversity and ecosystem functions after perturbations. However, we still know little about the legacy effects of past forestation on the ecological mechanisms involved in grassland recovery, especially regarding long‐lasting impacts on plant–pollinator interaction networks and plant reproduction. Here, our objective is to fill this knowledge gap by comparing plant and pollinator diversity, the degree of network specialization, the pollination success and pollen limitation of native plant species across 28 plant–pollinator networks of old and restored grasslands with different ages since restoration (from 2 to 75 years). We hypothesized that past forestation would have long‐lasting negative legacy effects on plant richness and plant–pollinator networks, increasing pollen limitation for native plants, thereby delaying the recovery of grassland communities in restored grasslands. The results showed that restored grasslands exhibited significantly lower plant richness, less specialized (more generalized) interaction networks, lower pollination success and pollen‐limited seed reproduction of native plants compared with the old grasslands. Lower network specialization was associated with reduced pollination function and decreased plant reproductive success, which likely led to slower recovery of plant diversity in restored meadows. We showed that such negative legacy effect was long‐lasting and maintained in the grasslands even 75 years after recovery. Synthesis and applications: Our findings suggest that the recovery of specialized plant–pollinator networks by enhancing plant diversity is essential for restoring pollination function. To restore such pollination networks and function, grassland management, including mowing, should be maintained for a certain period that exceeds at least 75 years. Encouraging the abundance of bees and butterflies is a key to facilitating plant recovery. Moreover, it is crucial to maintain neighbouring plant‐ and pollinator‐rich old grasslands, which support the recovery by serving as sources of native seeds and pollinators.Last, Wiley, Mar. 2025, Journal of Applied Ecology, 62(4) (4), 814 - 823, English[Refereed]Scientific journal
- Societal Impact Statement Prescribed burning shows promise for managing certain grassland types, but relying solely on it often reduces plant diversity, including threatened species. In Japanese dry grasslands established on volcanic ejecta, we explored conditions under which burning maintains high diversity. Lava grasslands, especially those on young lava flows with hard, shallow, and acidic soil and high rock and stone cover, harbored the most diverse plants, including threatened species. Burning helps prevent forest encroachment, efficiently maintaining species‐rich grasslands on lava flows. We recommend this approach to land managers for maintaining grasslands and conserving threatened plants, particularly in shallow, acidic soil conditions. Summary Prescribed burning can be an effective and efficient method for managing large areas of grasslands, particularly in face of global increases in grassland abandonment. However, relying solely on regular burning often leads to declines in diversity of grassland plants including threatened species in Eurasian countries. Therefore, investigating conditions under which prescribed burning effectively conserves threatened species is highly important. We hypothesized that under specific soil physicochemical conditions, even burning‐only management can maintain high threatened species diversity. To test the hypothesis, we compared soil physicochemical properties and vegetation among burning‐managed grasslands on different volcanic bedrocks (young/old lava and scoria) in Nashigahara, Yamanashi, Japan. We quantitatively investigated how bedrock, soil, and vegetation properties affected diversity of plants, including threatened species. We found the highest plant diversity in young lava grasslands, which were characterized by hard and shallow soil and high rock and stone cover, than old lava and young/old scoria grasslands. Meanwhile, soil nutrients (N, P, K, Ca, and Mg) did not vary among bedrock types and had no significant effects on plant diversity. In young lava grasslands, shallow soil, low soil pH, and resulting low vegetation height caused high threatened species diversity, supporting the hypothesis. Mature vegetation on lava flows often comprises forests worldwide. Nonetheless, our findings suggest that prescribed burning successfully suppresses tree dominance and promotes the establishment of highly species‐rich grasslands on lava flows. We propose that prescribed burning can effectively conserve threatened species in semi‐natural grasslands established under specific soil environments, such as those on lava flows.Wiley, Jan. 2025, PLANTS, PEOPLE, PLANET, English[Refereed]Scientific journal
- Springer Science and Business Media LLC, Jan. 2025, The Science of Nature, 112(1) (1), 13, English[Refereed]Scientific journal
- Elsevier BV, Nov. 2024, Journal of Environmental Management, 370, 122676 - 122676, English[Refereed]Scientific journal
- Elsevier BV, Sep. 2024, Journal of Environmental Management, 368, 122120 - 122120, English[Refereed]Scientific journal
- Abstract Background and Aims Urbanization-induced environmental changes affect the geographical distribution of natural plant species. This study focused on how polyploidization, a dynamic genome change, influences the survival and distribution of Commelina communis (Cc) and its subspecies C. communis f. ciliata (Ccfc), which have variable chromosome numbers (e.g. Cc, 2n = 88 for Cc; Ccfc, 2n = 46 for Ccfc). The aim was to investigate polyploidization effects on natural plant distribution in urban environments. Methods The geographical distribution across urban–rural gradients was investigated at a total of 218 sites in Japan. Stomata size and density were measured and compared between Cc and Ccfc. Flow cytometry determined genome size and polyploidy. Chromosome karyotyping was performed using the genomic in situ hybridization (GISH) method. Key Results Urban areas were exclusively dominated by Cc, while Cc and Ccfc coexisted in rural areas. Cc had larger and fewer stomata and a genome size more than twice that of Ccfc. GISH results indicated that Cc possesses Ccfc and another unknown genome, suggesting allopolyploidy. Conclusions Our results show that the ploidy difference affects the geographical distribution, stomata traits and genome size between two distinct taxa in the genus Commelina, C. communis as a neo-tetraploid and C. communis f. ciliata, the diploid. Cc is an allopolyploid and is therefore not only polyploidy but also has an additional genome that provides new sets of genes and alleles, contributing to Cc having enhanced survival potentials in urban environments compared with Ccfc. This is the first investigation to clarify the distribution difference related to urban environments, the difference in stomata traits and genome size, and to study chromosome composition in Commelina species.Oxford University Press (OUP), Aug. 2024, Annals of Botany, English[Refereed]Scientific journal
- Abstract Reproductive interference is defined as an interspecific interaction that reduces fitness via mating processes. Although its ecological and evolutionary consequences have attracted much attention, how reproductive interference affects the population genetic structures of interacting species is still unclear. In flowering plants, recent studies found that self-pollination can mitigate the negative effects of reproductive interference. Selfing-biased seed production is expected to increase population-level inbreeding and the selfing rate, and limits gene flow via pollinator outcrossing among populations. We examined the population genetics of the mixed-mating annual herb Commelina communis f. ciliata, focusing on reproductive interference by the sympatric competing congener C. communis using microsatellite markers. First, we found that almost all C. c. f. ciliata populations had relatively high inbreeding coefficients. Then, comparing sympatric and allopatric populations, we found evidence that reproductive interference from a competing congener increased the inbreeding coefficient and selfing rate. Allopatric populations exhibit varied selfing rates while almost all sympatric populations exhibit extremely high selfing rates, suggesting that population selfing rates were also influenced by unexamined factors, such as pollinator limitation. Besides, our findings revealed that reproductive interference from a competing congener did not limit gene flow among populations. We present the first report on how reproductive interference affects the genetic aspects of populations. Our results suggested that the high selfing rate of C. c. f. ciliata promotes its sympatric distribution with C. communis, even in the presence of reproductive interference, although it is not clear whether reproductive interference directly causes the high selfing rate.Springer Science and Business Media LLC, Aug. 2024, Oecologia, English[Refereed]Scientific journal
- Abstract Past forest use often has a long‐term negative impact on the recovery of the original plant composition of semi‐natural grasslands, which is known as a legacy effect. This study investigates the impact of seed dispersal limitations on the restoration of grassland plant diversity on ski slopes with past forest use, highlighting the negative legacy effect on biodiversity recovery. Focusing on ski areas, our research contrasts the vegetation on ski slopes originally created on semi‐natural grasslands such as pasture (pasture slopes) and constructed by clearing secondary forests or conifer plantations (forest slopes). We examined species richness and diversity, considering seed dispersal modes, grassland management history, and seed source proximity. We reveal that the proximity to species‐rich grassland sources is pivotal for the restoration of native grassland vegetation. Particularly, wind‐dispersed species show significant recovery on slopes with sustained management for more than 70 years and those with neighboring species‐rich grasslands, suggesting that both the duration of management and the proximity to seed sources are critical for overcoming the legacy effects of past forest use. Meanwhile, gravity‐dispersed species failed to recover their richness and diversity regardless of both the duration of management and the proximity to seed source grasslands, which their diversity recovered where seed sources neighbored. Our findings emphasize the importance of considering seed dispersal limitation and management history in the restoration and conservation of grasslands and their biodiversity, particularly in landscapes experiencing past human intervention.Wiley, Jul. 2024, Ecology and Evolution, 14(7) (7), English[Refereed]Scientific journal
- Elsevier BV, Jul. 2024, Biological Conservation, 110686 - 110686, English[Refereed]Scientific journal
- Abstract Urban development greatly alters the natural and semi‐natural habitats of native plants. Urbanisation results in a range of diverse habitats including remnant agricultural lands, urban parks, and roadside habitats. This habitat diversity often promotes trait divergence within urban areas. However, the mechanisms by which diverse urban habitats influence the population genetic structure of individual plant species remain poorly understood. We investigated the effects of urbanisation on genetic diversity and structure within 24 Commelina communis populations across diverse habitat types (rural agricultural land, urban agricultural land, urban park land, and urban roadsides) within the Kyoto–Osaka–Kobe megacity in Japan. We conducted multiplexed inter‐simple sequence repeat genotyping to compare genetic diversity among populations in different habitats. We also examined the correlation between Nei's genetic distance and geographic and environmental distances and performed principal coordinate analysis (PCoA) to evaluate genetic differentiation among urban habitats. There were no significant differences in genetic diversity indices between urban and rural populations and among urban habitat types. Although we detected no isolation‐by‐distance structure in population pairs of the same habitat type and in those of different habitats, the difference in surrounding landscape facilitated genetic differentiation not only between urban and rural habitats but also between different urban habitats. PCoA revealed no clear genetic differentiation among rural and urban habitat populations. Our findings indicate that the establishment of diverse habitat types through urbanisation has no and little impact on genetic diversity and structure, respectively, in C. communis, likely due to its high selfing rate and ability to adapt to urban conditions.Wiley, Feb. 2024, Ecology and Evolution, 14(2) (2), English[Refereed]Scientific journal
- Abstract Loss of animal species and functional diversity can degrade ecosystem functions and services in plant–animal mutualistic networks, but their relative effects have rarely been previously examined in natural communities. Contrary to previously published theoretical results, under natural conditions, changes in pollinator functional niches caused by species and functional diversity losses are dynamic and often unpredictable. The lack of studies on natural networks limits our ability to predict future effects of decreasing pollinator diversity on wild and cultivated plants. We quantitatively evaluated the relative effects of pollinator species and functional diversity loss on plant–pollinator trait matching and pollination success across 40 spatiotemporally variable coastal networks. We found that low pollinator functional diversity (low abundance of long‐tongued pollinators) reduced community‐level plant functional specialization and trait matching between flowers and pollinators by reducing functional floral‐niche partitioning among pollinators. In contrast, pollinator species diversity did not influence community‐level trait matching. Furthermore, decreasing community‐level trait matching had a negative effect on community‐level plant pollination success, regardless of flower morphology. The present study demonstrated that pollinator functional diversity loss, rather than species diversity loss, was the main factor contributing to pollination functional loss in the plant–pollinator networks studied. We also demonstrated the importance of assessing functional aspects of plant–pollinator networks to evaluate community‐level pollination functional loss under global pollinator decline. Read the free Plain Language Summary for this article on the Journal blog.Last, Wiley, Feb. 2024, Functional Ecology, English[Refereed]Scientific journal
- Feb. 2024, Limnology, (in press), English[Refereed]Scientific journal
- Abstract Many wetland plants rely on insects for pollination. However, studies examining pollinator communities in wetlands remain limited. Some studies conducted in large wetlands (> 10 ha) have suggested that wetland-dependent flies, which spend their larval stage in aquatic and semi-aquatic habitats, dominate as pollinators. However, smaller wetlands surrounded by secondary forests are more prevalent in Japan, in which pollinators from the surrounding environment might be important. Additionally, information regarding floral traits that attract specific pollinator groups in wetland communities is scarce. Therefore, this study aimed to understand the characteristics of insect pollinators in a small natural wetland (2.5 ha) in Japan. We examined the major pollinator groups visiting 34 plant species and explored the relationship between the flower visitation frequency of each pollinator group and floral traits. Overall, flies were the most dominant pollinators (42%), followed by bees and wasps (33%). Cluster analysis indicated that fly-dominated plants were the most abundant among 14 of the 34 target plant species. However, 85% of the hoverflies, the most abundant flies, and 82% of the bees were non-wetland-dependent species, suggesting that these terrestrial species likely originated from the surrounding environment. Therefore, pollinators from the surrounding environment would be important in small natural wetlands. Flies tend to visit open and white/yellow flowers, whereas bees tended to visit tube-shaped flowers, as in forest and grassland ecosystems. The dominance of flies in small wetlands would be due to the dominance of flowers preferred by flies (e.g., yellow/white flowers) rather than because of their larval habitats.Springer Science and Business Media LLC, Jan. 2024, Journal of Plant Research, 137(2) (2), 191 - 201, English[Refereed]Scientific journal
- Abstract Environmental changes associated with urbanisation can exert pressure that facilitates both adaptations and plastic responses in plants. Field surveys or common garden experiments (CGE) alone cannot differentiate between the observed phenotypic traits resulting from plastic responses versus evolutionary adaptations to urban environments. We conducted a field survey of habitat environmental factors and four vegetative traits in 12 Commelina communis populations along an urban–rural gradient in the Osaka‐Kobe megacity area. We collected seedlings from six of the 12 populations, transplanted them into a greenhouse, and measured six vegetative traits. We investigated correlations between pairs of measured traits in both the field survey and CGE. Plant height and leaf area increased significantly in increasingly developed land areas (DLA) in the field survey, whereas no such variations were found in the CGE, suggesting that the observed phenotypic variation was due to a plastic response to urban eutrophication. Leaf number and specific leaf area (SLA) significantly decreased with increasing DLA in the CGE, suggesting the adaptation of these traits to urban environments. Positive correlations between plant height and leaf area were only observed in urban populations in both the field survey and CGE, indicating the evolution of this trait correlation in urban environments. It has been suggested that urban environments promote both plastic response and genetic divergence of a set of traits in native plants. Our findings suggest that low leaf number, SLA, and positive plant height–leaf area correlations have evolved. In addition, larger plant size is achieved via phenotypic plasticity in urban environments.Last, Wiley, Nov. 2023, Plant Biology, 26(1) (1), 74 - 81, English[Refereed]Scientific journal
- Abstract This study proposes a practice and discussion for an interdisciplinary approach to policies for the conservation of suburban and peri-urban ecosystems. We highlight the need for evidence-based assessment of the current quality of the targeted nature from perspectives of natural science and problem formulation, and that causes should be investigated from the combined perspectives of social science, economic evaluation, and policy design and evaluation, with an awareness of the possibility of consensus building. In this study, based on the ongoing international trend of ecosystem conservation, an economic analysis was conducted to examine the direction of Satoyama development as a case study of urban and peri-urban ecosystem conservation. The result identified the preference and needs of citizens with regard to Satoyama ecosystems and discussed the consistency between policy targets and citizens’ evaluation.Springer Science and Business Media LLC, Jul. 2023, International Journal of Economic Policy Studies, 17(2) (2), 403 - 419, English[Refereed]Scientific journal
- Wiley, May 2023, Plant Species Biology, English[Refereed][Invited]Scientific journal
- Elsevier BV, Apr. 2023, City and Environment Interactions, 18, 100101 - 100101, English[Refereed]Scientific journal
- Wiley, Feb. 2023, American Journal of Botany, English[Refereed]Scientific journal
- Last, Informa UK Limited, Dec. 2022, Journal of Apicultural Research, 1 - 8, English[Refereed]Scientific journal
- Last, Wiley, Jun. 2022, People and Nature, 4(5) (5), 1176 - 1189, English[Refereed]Scientific journal
- Wiley, Mar. 2022, Plant Biology, English[Refereed]Scientific journal
- Springer Science and Business Media LLC, Jan. 2022, Landscape and Ecological Engineering, 19(1) (1), 3 - 10, English[Refereed]Scientific journal
- Andromonoecy, the presence of perfect and staminate flowers in the same individual, has evolved repeatedly in angiosperms. The staminate flowers are generally smaller than the perfect flowers in species that produce staminate flowers plastically when resources are limited. The smaller staminate flowers are expected to be less attractive to pollinators and have reduced size-matching with pollinators than perfect flowers. We hypothesized that these potential disadvantages of staminate versus perfect flowers facilitate the evolution of sex-specific floral morphology, such as allometric relationship between flower size and male reproductive organ. We compared six floral morphology traits, pollen production, pollinator visits and pollen removal from anthers between staminate and perfect flowers in several natural Commelina communis populations. Nectarless and zygomorphic C. communis flowers have polymorphic stamens with attracting, feeding and pollinating anthers and were visited by diverse pollinators. Staminate flowers were significantly smaller than perfect flowers, despite a large overlap in size between sexes. The lengths of pollinating stamens did not differ between staminate and perfect flowers, and staminate flowers produced significantly more pollen. We observed significantly more pollinator visits to perfect flowers than to staminate flowers. By contrast, pollen removal from pollinating stamens was significantly higher in staminate flowers than in perfect flowers. There is sexual dimorphism in flower morphology in C. communis. Staminate flowers with smaller attraction organs, similar pollinating stamens and higher pollen production assure higher pollen donor success relative to perfect flowers. Our results suggest that the morphological changes in staminate flowers enhance pollination success, even with limited resources.Last, Wiley, Jan. 2022, Plant Biology, English[Refereed]Scientific journal
- Pollinator-mediated reproductive interference can occur when two or more plant species share the same pollinators. Recent studies have suggested that prior autonomous selfing mitigates reproductive interference, potentially facilitating coexistence even in the absence of pollination niche partitioning (i.e. the pre-emptive selfing hypothesis). However, whether the evolution of prior selfing promotes coexistence, in the context of the eco-evolutionary dynamics of population size, selfing rates and inbreeding depression, remains poorly understood. We constructed an individual-based model to examine the conditions under which the evolution of prior selfing promotes coexistence in the context of mutual reproductive interference. In the model, two plant species compete by way of mutual reproductive interference, and both have the potential to evolve the capacity for prior autonomous selfing. We expected that purging of deleterious mutations might result in evolutionary rescue, assuming that the strength of inbreeding depression declines as the population selfing rate increases; this would enable inferior competitors to maintain population density through the evolution of prior selfing. Our simulation demonstrated that evolution of prior selfing may promote coexistence, whereas reproductive interference in the absence of such evolution results in competitive exclusion. We found that lower pollinator availability is likely to favour rapid evolutionary shifts to higher prior selfing rates, thereby neutralising the negative effects of reproductive interference in both species. When the strength of inbreeding depression decreased with an increase in the population-level selfing rate, moderate pollinator availability resulted in long-term coexistence in which relative abundance-dependent selection on the prior selfing rate served to intermittently maintain the population density of the inferior competitor. Synthesis. We demonstrate that the evolution of prior selfing may increase population growth rates of inferior competitors and may consequently promote long-term coexistence via an evolutionary rescue. This constitutes a novel mechanism explaining the co-evolutionary coexistence of closely related plant species without niche partitioning, and is consistent with recent studies reporting that closely related species with mixed mating systems can co-occur sympatrically, even under conditions of mutual reproductive interference.Last, Wiley, Sep. 2021, Journal of Ecology, 109(11) (11), 3916 - 3928, English[Refereed]Scientific journal
- Aims Understanding fine-grain diversity patterns across large spatial extents is fundamental for macroecological research and biodiversity conservation. Using the GrassPlot database, we provide benchmarks of fine-grain richness values of Palaearctic open habitats for vascular plants, bryophytes, lichens and complete vegetation (i.e., the sum of the former three groups). Location Palaearctic biogeographic realm. Methods We used 126,524 plots of eight standard grain sizes from the GrassPlot database: 0.0001, 0.001, 0.01, 0.1, 1, 10, 100 and 1,000 m(2) and calculated the mean richness and standard deviations, as well as maximum, minimum, median, and first and third quartiles for each combination of grain size, taxonomic group, biome, region, vegetation type and phytosociological class. Results Patterns of plant diversity in vegetation types and biomes differ across grain sizes and taxonomic groups. Overall, secondary (mostly semi-natural) grasslands and natural grasslands are the richest vegetation type. The open-access file "GrassPlot Diversity Benchmarks" and the web tool "GrassPlot Diversity Explorer" are now available online () and provide more insights into species richness patterns in the Palaearctic open habitats. Conclusions The GrassPlot Diversity Benchmarks provide high-quality data on species richness in open habitat types across the Palaearctic. These benchmark data can be used in vegetation ecology, macroecology, biodiversity conservation and data quality checking. While the amount of data in the underlying GrassPlot database and their spatial coverage are smaller than in other extensive vegetation-plot databases, species recordings in GrassPlot are on average more complete, making it a valuable complementary data source in macroecology.Wiley, Jul. 2021, Journal of Vegetation Science, 32(4) (4), English[Refereed]Scientific journal
- Wiley, Apr. 2021, Plant Biology, 23(5) (5), 711 - 718, English[Refereed]Scientific journal
- Premise: Understanding the flower visitation history of individual pollinators is key in the study of pollination networks, but direct tracking is labor intensive and, more important, does not capture information about the previous interactions of an individual. Therefore, a protocol to detect most of the pollen species on the body surfaces of an individual pollinator could elucidate its flower visitation history. Methods and Results: Under a microscope, we observed 6.0-µL droplets from a sample solution (1.0 or 3.0 mL) containing pollen grains collected from individuals of six major pollinator functional groups. To clarify how many droplets need to be observed to detect all pollen species within the solution, we examined up to 10 droplets collected from each individual insect. Sample-based rarefaction curve analyses of the data showed that we could detect ~90% of the pollen species and the plant-pollinator links in the networks by observing six droplets. Conclusions: The rarefaction curve analysis for pollen-on-pollinator studies is a useful preliminary step for minimizing the time and labor required while maximizing the data on the flower visitation history of each individual pollinator and revealing any hidden flower-pollinator interactions.Wiley, Feb. 2021, Applications in Plant Sciences, 9(2) (2), e11411, English, International magazine[Refereed]Scientific journal
- Seminatural grasslands are ecosystems rich in biodiversity. However, their decline has been reported worldwide, and identification of grasslands with high conservation priority is urgently required. Recently, an increasing number of studies have reported that past vegetation history affects current biological communities. To evaluate whether the temporal continuity of grasslands promotes biodiversity, and thus can be an indicator of conservation priority, we studied vascular plant communities in old (160-1000s years) and new (52-70 years after deforestation) grasslands, as well as in forests, of Sugadaira Highland in central Japan. The number of plant species was highest in old grasslands, followed by new grasslands and forests. This pattern was much clearer in the number of grassland-dependent native and grassland-dependent endangered species, indicating the role of old grasslands as refugia for those species. The species composition differed between old and new grasslands. New grasslands had species compositions in between those of old grasslands and forests, suggesting that the plant community in new grasslands retains the influence of past forestation for more than 52 years after deforestation. Eleven indicator species were detected in old grasslands, but none in new grasslands, suggesting the uniqueness of the plant community in old grasslands. We conclude that the temporal continuity of grasslands increases plant diversity and can be an indicator of grasslands with high conservation priority.Wiley, Jan. 2021, Ecological Research, 36(1) (1), 24 - 31, English[Refereed]Scientific journal
- The diversity and the abundance of amphibians have dramatically declined globally over the past 30 years, and the monitoring and conservation of their habitats is essential. However, traditional methods such as bait trapping and mark-recapture are costly, and morphological identification usually requires a high level of taxonomic expertise. Here, seasonal surveillances of Hida salamanderInter-Research Science Center, Nov. 2020, Endangered Species Research, 43, 341 - 352, English
Hynobius kimurae were performed by means of environmental DNA (eDNA) analysis withHynobius -specific primers and a species-specific TaqMan probe. Water sampling and visual surveys were conducted seasonally in a stream in Kyoto Prefecture, Japan. Detection rates of eDNA were then calculated by real-time PCR, and eDNA site occupancy probability was estimated by multi-scale occupancy modeling. The eDNA-based detection rate of Hida salamander was 76.7%, whereas the visual survey-based detection rate was 23.3%, and target eDNA was detected at almost all sites where the presence of target species was visually confirmed. Moreover, factors relating to the site- and sample-level occurrence probabilities of the target eDNA differed depending on the developmental stage of the target species. Our findings support previous studies showing that eDNA analysis enables an effective assessment of amphibian distributions without damaging the organisms or their habitat, and we compare for the first time the site occupancy probability of amphibian eDNA throughout the life cycle of an amphibian species. The present study contributes to the development of eDNA analysis as a tool for understanding the distribution and seasonal activity of amphibian species and will thus aid in the planning of conservation measures and habitat restoration for these species.[Refereed]Scientific journal - Elsevier, Jun. 2020, Encyclopedia of the World's Biomes, 785 - 799, English[Refereed][Invited]In book
- © 2020, Genetics Society of Japan. All rights reserved. Table 1 on p. 135 should be replaced with the corrected Table 1 shown bellow. (Table presented).Last, Genetics Society of Japan, Feb. 2020, Genes & Genetic Systems, 95(1) (1), 51 - 51, English[Refereed]Scientific journal
- Springer Science and Business Media LLC, Feb. 2020, Landscape and Ecological Engineering, 106(2) (2), 163 - 172, English[Refereed]Scientific journal
- Environmental DNA (eDNA) analysis has been used as a cost-efficient and non-invasive tool for monitoring invasive and threatened species. Previous studies typically involve two approaches; species-specific detection via PCR and multiple species detection via metabarcoding. However, the former could be costly when several species are targeted, and the latter could sometimes be insufficient to distinguish closely related species. Here, the simultaneous eDNA detection from multiple species via multiplex real-time PCR was applied to 99 ponds to evaluate the distribution of three exotic and three threatened native fish species over different seasons. We detected bluegill sunfish (Lepomis macrochirus) eDNA at 31 sites, largemouth bass (Micropterus salmoides) eDNA at 22 sites, smallmouth bass (Micropterus dolomieu) eDNA at one site, golden venus chub (Hemigrammocypris rasborella) eDNA at 11 sites, Japanese medaka (Oryzias latipes) eDNA at 26 sites, and weather loach (Misgurnus anguillicaudatus) eDNA at 41 sites. We found that eDNA detection rates were higher in early summer for all fish species. Moreover, exotic fish eDNA was detected more frequently in ponds which were easier to access by car and which have a larger surface area and higher pH. Furthermore, the detection rates of native fish eDNA were generally lower in the ponds where exotic fish eDNA was detected more frequently. Multiplex real-time PCR can help detect the distribution of exotic and threatened native species for conservation and ecosystem management. This method is expected to substantially contribute to the early detection of invasive species and the efficient protection of threatened species' habitat.SPRINGER, Feb. 2020, BIOLOGICAL INVASIONS, 22(2) (2), 455 - 471, English[Refereed]Scientific journal
- Last, Oct. 2019, American Journal of Botany, 106(10) (10), 1356 - 1364, EnglishDoes sexual dimorphism exist in flowering phenology traits in anemophilous dioecious species?: a test with Rumex acetosa[Refereed]Scientific journal
- Jul. 2019, Hacquetia, 18(2) (2), 143 - 146Conservation and diversity of Palearctic grasslands - Editorial to the 5th EDGG special issue in Hacquetia.[Refereed]Scientific journal
- Last, Jul. 2019, Palaearctic Grasslands, 42, 16 - 22, EnglishSki runs as an alternative habitat for threatened grassland plant species in Japan[Refereed]Scientific journal
- Commelina communis f. ciliata (Commelinaceae), a newly distinguished taxon, is an annual andromonoecious herb exhibiting a mixed mating system, the details of which remain unclear. We developed microsatellite markers for use in exploring the evolution of andromonoecy and mixed mating in the species. Fifteen micro satellite loci were developed using next-generation sequencing. The primer sets were used to evaluate 65 C. communis f. ciliata individuals from three populations in Japan; we found 1-13 alleles per locus and the expected heterozygosity ranged from 0.00 to 0.76. The markers are potentially useful to examine intra- and inter-species genetic structure and the mixed mating strategy of Commelina species via paternity analysis.Last, GENETICS SOC JAPAN, Jun. 2019, GENES & GENETIC SYSTEMS, 94(3) (3), 133 - 138, English[Refereed]Scientific journal
- Last, May 2019, Functional Ecology, 33(8) (8), 1504 - 1513, EnglishPrior selfing can mitigate the negative effects of mutual reproductive interference between coexisting congeners.[Refereed]Scientific journal
- Background and Aims Large clades of angiosperms are often characterized by diverse interactions with pollinators, but how these pollination systems are structured phylogenetically and biogeographically is still uncertain for most families. Apocynaceae is a clade of >5300 species with a worldwide distribution. A database representing >10 % of species in the family was used to explore the diversity of pollinators and evolutionary shifts in pollination systems across major clades and regions.Methods The database was compiled from published and unpublished reports. Plants were categorized into broad pollination systems and then subdivided to include bimodal systems. These were mapped against the five major divisions of the family, and against the smaller clades. Finally, pollination systems were mapped onto a phylogenetic reconstruction that included those species for which sequence data are available, and transition rates between pollination systems were calculated.Key Results Most Apocynaceae are insect pollinated with few records of bird pollination. Almost three-quarters of species are pollinated by a single higher taxon (e.g. flies or moths); 7 % have bimodal pollination systems, whilst the remaining approx. 20 % are insect generalists. The less phenotypically specialized flowers of the Rauvolfioids are pollinated by a more restricted set of pollinators than are more complex flowers within the Apocynoids + Periplocoideae + Secamonoideae + Asclepiadoideae (APSA) clade. Certain combinations of bimodal pollination systems are more common than others. Some pollination systems are missing from particular regions, whilst others are over-represented.Conclusions Within Apocynaceae, interactions with pollinators are highly structured both phylogenetically and biogeographically. Variation in transition rates between pollination systems suggest constraints on their evolution, whereas regional differences point to environmental effects such as filtering of certain pollinators from habitats. This is the most extensive analysis of its type so far attempted and gives important insights into the diversity and evolution of pollination systems in large clades.Oxford University Press (OUP), Jan. 2019, Annals of Botany, 123(2) (2), 311 - 325, English[Refereed]Scientific journal
- Schweizerbart, Aug. 2018, Phytocoenologia, 48(3) (3), 331 - 347[Refereed]Scientific journal
- This study focuses on the importance of subjective perceptions in the valuation and conservation of urban green spaces. Because physical attributes of the natural environment are filtered through individuals' perceptions, their self-reporting of the extent of green spaces fluctuates according to their biases. However, the determinant of people's self-reporting of the extent of green spaces within neighborhoods remains unclear. An examination of the relationship between the physical attributes of green spaces and the self-reported extent of green spaces is required to address this uncertainty. Accordingly, two separate studies were conducted by establishing two types of data on green spaces: physical data derived from a Geographical Information System and questionnaire-derived self-reported data. Multiple regression analysis was performed to compare the effects of different types of physical green spaces on the self-reported extent of green spaces. The results indicated that residents' perceptions of same-sized green spaces differed considerably depending on their type. To ascertain the effects of subjective perceptions on economic valuation, a life satisfaction approach was subsequently applied within two separate analyses. In the first analysis, reflecting a normal pattern, the relationship between life satisfaction and the area of green space was examined, and in the second analysis, the self-reported extent of green spaces was used as an intermediate variable between green spaces and life satisfaction. A comparison of the estimated values from the two analyses revealed significant differences, depending on whether self-reported green spaces were used as an intermediate variable. Specifically, values of urban green spaces fluctuated more than those of forests in the case of self-reported green spaces. Although urban planners and experts generally emphasize the physical attributes of green spaces, such as area, these results indicate that it is critical to consider people's perceptions.ELSEVIER GMBH, URBAN & FISCHER VERLAG, Aug. 2018, URBAN FORESTRY & URBAN GREENING, 34, 166 - 174, English[Refereed]Scientific journal
- The biodiversity of agricultural landscapes has been noticeably affected by rapid urbanization. Although many studies have examined species diversity per unit area (alpha diversity), knowledge about the patterns of species turnover (beta diversity) in urban areas remains limited. Furthermore, most beta diversity studies have focused on spatial heterogeneity however, losses of temporal heterogeneity resulting from urbanization remain limited. In this study, we examined how urbanization is associated with decreases in the seasonal heterogeneity of species composition, which could be used as an indicator of the loss of seasonality by ecologists and policy makers aiming to conserve biodiversity. We investigated (1) changes in species richness based on seasonal averages (alpha diversity) and (2) the seasonal turnover of species composition (beta diversity) for flowering plants and butterflies along a rural-urban gradient in semi-natural grasslands. The response variables were alpha and beta diversity for flowering plants and butterflies, and the explanatory variables were urban areas within a 1-km radius of the center of each site. Increasing urban area caused both the seasonal alpha and beta diversity of flowering plants and butterflies to decline. These results supported the homogenization hypothesis for the seasonality of plants and butterflies in semi-natural grasslands of dominant urban areas in East Asia. Future studies should focus on investigating how urbanization is causing both declines in seasonality and changes in the spatial heterogeneity of species composition and associated biodiversity loss. Ecologists and policy makers should focus on developing strategies to halt the loss of temporal biological heterogeneity to maintain biodiversity.Last, Elsevier GmbH, Jun. 2018, Basic and Applied Ecology, 29, 1 - 11, English[Refereed]Scientific journal
- Historical changes in grassland area determined the demography of semi-natural grassland butterflies in JapanSemi-natural grassland areas expanded worldwide several thousand years ago following an increase in anthropogenic activities. However, semi-natural grassland habitat areas have been declining in recent decades due to changes in landuse, which have caused a loss of grassland biodiversity. Reconstructing historical and recent demographic changes in semi- natural grassland speciesFeb. 2018, Heredity, 121, 151 - 168, English[Refereed]Scientific journal
- This study investigated the effect of valuators' personal history and beliefs on valuation of ecosystem services around Mt. Rokko, which is located near Kobe, a major city in Japan. Special attention was paid to how differences in lifestyle, access to nature, and experiences during childhood influence willingness to pay (WTP) for peri-urban ecosystem conservation. The estimated values (median: 1858 JPY) were relatively higher than in previous case studies including one on the World Heritage forest in the country, but the value was not outlier of the literature. From the simple model estimation, we focused on the effect of individual differences. The full model including information of personal experience with nature revealed differences in WTP among residents. The basic characteristics of age and income were found to have a significant effect. Interestingly, it was also found that certain experiences during childhood had a significant effect on increasing WTP for ecosystem and biodiversity conservation. These findings suggest the importance of considering the diversity of valuators in ecosystem valuation studies under urbanization processes, and it also warns the extinction of experience with nature under on going urbanization for urban ecosystem conservation.ELSEVIER GMBH, URBAN & FISCHER VERLAG, Dec. 2017, URBAN FORESTRY & URBAN GREENING, 28, 110 - 117, English[Refereed]Scientific journal
- Jul. 2017, 環境科学会誌, 30(4) (4), 238 - 249, Japanese満足度指標を用いたとし緑地の経済価値評価[Refereed]Scientific journal
- Despite the well-known visual attraction function of angiosperm petals, additional roles of these floral organs (e.g. the provision of landing-site platforms for pollinators) have rarely been examined. This is likely because most petals perform multiple functions, making it difficult to isolate the importance of landing sites in pollination success. We investigated the landing-site function of dull-coloured pinnately branched petals in Mitella pauciflora flowers, which are predominantly pollinated by fungus gnats. We conducted a field experiment, in which the effects of experimental petal removal on pollinators' approach, landing and visit duration and floral reproductive success were examined in naturally pollinated flowers. According to direct and time-lapse camera observations, petal removal did not influence pollinators' approach frequency or visit duration, but did significantly decrease their landings. Fruit set and pollen dispatch both significantly decreased with petal removal, indicating that petals promote female and male reproductive success in M.pauciflora by facilitating pollinator landing. This demonstrates that inconspicuous petals primarily have a landing-site function rather than a visual attraction function in M.pauciflora. Discriminating between diverse petal functions is a challenging problem, and new approaches are required to elucidate the functional features of angiosperm flowers. A is available for this article.Last, WILEY, Jun. 2017, FUNCTIONAL ECOLOGY, 31(6) (6), 1193 - 1200, English[Refereed]Scientific journal
- Functional diversity loss among pollinators has rapidly progressed across the globe and is expected to influence plant–pollinator interactions in natural communities. Although recent findings suggest that the disappearance of a certain pollinator functional group may cause niche expansions and/or shifts in other groups, no study has examined this prediction in natural communities with high plant and pollinator diversities. By comparing coastal pollination networks on continental and oceanic islands, we examined how community-level flower visit patterns are influenced by the relative biomass of long-tongued pollinators (RBLP). We found that RBLP significantly correlated with pollinator functional diversity and was lower in oceanic than in continental islands. Pollinator niches shifted with decreasing RBLP, such that diverse species with various proboscis lengths, especially short-tongued species, increasingly visited long-tubed flowers. However, we found no conspicuous negative impacts of low RBLP and the consequent niche shifts on pollinator visit frequencies to flowers in oceanic island communities. Notably, fruit set significantly decreased as RBLP decreased in a study plant species. These results suggest that niche shifts by other functional groups can generally compensate for a decline in long-tongued pollinators in natural communities, but there may be negative impacts on plant reproduction.Last, The Royal Society, Jan. 2017, Proceedings of the Royal Society B: Biological Sciences, 284(1846) (1846), 20162218 - 20162218, English[Refereed]Scientific journal
- Last, 2017, 岐阜県植物研究会誌, 33, 1 - 7, Japanese雌雄異株樹木イヌツゲにおける栄養生長形質の性的二型．[Refereed]Scientific journal
- HANA ABU, Nov. 2016, The Dipterist's Club of Japan, 42, 43 - 46, JapaneseHoverfly visitations to coastal fowers in Honshu and Izu islands.Scientific journal
- Established method of deposited pollen grains on the surface of pollinated insect bodyDescribing plant-pollinator interaction webs has provided a basis of evolutionary ecol- ogy of plant reproduction and mutualistic network analyses. Although most previous studies described plant-pollinator interactions by observing pollinator visits to owers, some inter- actions could be missed by the pollinator observation. Hence, recording pollen grains on pollinator bodies日本花粉学会, Sep. 2016, Japanese journal of palynology, 62(1) (1), 3 - 7, Japanese[Refereed]Scientific journal
- The effect of land-use changes on plant diversity is an important issue, as plant diversity is vital to maintaining of threatened insect diversity in agro-ecosystems. Although many studies have examined patterns of a few threatened species, few studies have examined a large number of threatened species while comparing organisms of different trophic levels. Observed and expected community assembly patterns of common and threatened species should be evaluated along land-use gradients in agro-ecosystems, using species richness and red list indicator (RLI). This study examined local and regional diversity of plants and herbivorous insects among abandoned, traditional, and intensified land-use types in semi-natural grasslands and compared observed and expected values via null model analysis. This study showed that the richness and RH of plants and herbivorous insects were maintained in the traditional land-use. However threatened plants and herbivorous insects at sites of land abandonment and intensified use were significant lower than null model expectations. Although, plant richness, rather than RLI, was responsible for maintaining richness and the RLIs of herbivorous insects, plant richness did not linearly correlate with plant RLIs. Threatened plants did not depend on plant richness, it will be vital to identify and conserve unique environments for diversity of plants and herbivores. In conclusion, we should reintroduce traditional land-use practices in intensified use and abandoned grasslands. National and local governmental support for the appropriate management of semi-natural grasslands is beneficial for biodiversity conservation at both the local (e.g., present study area) and national (Japanese) levels. (C) 2016 Elsevier Ltd. All rights reserved.Last, ELSEVIER SCI LTD, Sep. 2016, BIOLOGICAL CONSERVATION, 201, 270 - 276, English[Refereed]Scientific journal
- Jun. 2016, Applied Vegetation Science, 19, 567 - 577, EnglishTraditional burning and mowing practices support high grassland plant diversity by providing intermediate levels of vegetation height and soil pH[Refereed]Scientific journal
- Celes akitanus was rediscovered in semi-natural grasslands in Japan. This species is one of the most endangered insects in Japan; most local populations were thought to be extinct. Reliable records of this rare species had been obtained only from Yamagata, Niigata, Tokyo and Nagano Prefectures. We compared the morphology of the holotype of Oedipoda akitana (= C. akitanus) and newly collected specimens and found that they matched with each other. The species was redescribed based on the holotype and new specimens. A molecular phylogenetic analysis involving other acridid species indicated that our samples were practically identical to C. akitanus from China. We conclude that the specimens we collected are C. akitanus, which has been rediscovered in Japan after about 30years. Because the discovered populations were restricted to narrow and scattered areas, conservation of these populations should be a high priority. Population monitoring and habitat assessment are required. Because C. akitanus and many other endangered species are found in the grassland areas, these habitats should be protected and maintained.Last, WILEY-BLACKWELL, Apr. 2016, ENTOMOLOGICAL SCIENCE, 19(2) (2), 89 - 96, English[Refereed]Scientific journal
- Recent global land-use changes have led to reductions in many herbaceous plant species in semi-natural grassland landscapes. Changes in management frequency and intensity are known to cause declines in plant populations. However, little is known about the impact of changes in the timing of management practices on the genetic diversity as well as the reproductive success of rare semi-natural grassland species. We determined the suitable management (mowing) timing for Vincetoxicum pycnostelma Kitag. (Apocynaceae; Asclepiadoideae), an endangered summer- and autumn-blooming semi-natural grassland herb. We examined 15 V. pycnostelma populations to assess the effects of mowing timing on the genetic diversity of each population using nine microsatellite markers and on pollination and reproductive success. Pollination success was not affected by flowering timing. Mowing during the mid- to late flowering and fruiting periods of V. pycnostelma (July-September) had a significant negative effect on the number of inflorescences and total fruits produced, whereas mowing before flowering and growing periods (April, May and November-March) had positive effects on the number of inflorescences and fruits, respectively. Furthermore, mowing during the mid- to late flowering and fruiting periods also caused a significant decrease in genetic diversity. Our results demonstrated that mowing events during the mid- to late flowering and fruiting periods caused significant declines in the genetic diversity and/or reproductive success of V pycnostelma. By contrast, mowing before flowering periods significantly enhanced reproductive success. To conserve semi-natural grassland herb diversity, mowing should be avoided during seasons when the flowering and fruiting periods of many endangered species overlap. (C) 2016 Elsevier B.V. All rights reserved.ELSEVIER, Apr. 2016, AGRICULTURE ECOSYSTEMS & ENVIRONMENT, 221, 20 - 27, English[Refereed]Scientific journal
- Biodiversity declines have been driven by land-use changes in semi-natural grasslands worldwide. This is thought to be because threatened species are unable to compete with generalist species, which are better adapted to the new environments created by modern land-use management. Many studies have separately examined biodiversity declines resulting from land abandonment and intensified use, however few have examined their unified effects on biodiversity. In addition, we still do not fully understand the relative importance of decreasing habitat area in comparison to changes in land-use practice with regard to biodiversity. To clarify the roles of these interconnected variables, we compared the diversity of threatened and common herbivorous insects and plants among four land-use types (traditional, annual burning, annual mowing, and abandoned) during 2012 and 2013. Next, we examined whether a relationship exists between herbivorous insects and environmental variables (species richness of plants, as well as current and historical grassland areas). We showed that land-use changes (annual burning, annual mowing and/or land abandonment) diminished the diversity of threatened butterflies, orthopterans, and plants. Herbivorous insects were affected by land-use practices rather than grassland area. Our results suggest that to conserve threatened species in semi-natural grasslands, we should reintroduce traditional land-use practices in areas that currently experience modern practices, such as annual mowing and burning. The reintroduction of traditional management practices would allow for the recovery of plant biodiversity, thereby increasing herbivorous insect diversity. (C) 2016 Elsevier B.V. All rights reserved.Last, ELSEVIER SCIENCE BV, Apr. 2016, AGRICULTURE ECOSYSTEMS & ENVIRONMENT, 221, 156 - 162, English[Refereed]Scientific journal
- In recent years, the degradation of biodiversity has advanced significantly, especially in freshwater ecosystems. To conserve rare species, the distribution of the target species should be known, even if the density is very low. Traditional habitat surveys using direct catches or observations require much time, labor, and expertise. Over the last decade, environmental DNA (eDNA) analysis methods that complement traditional surveys have been developed. In the present study, we developed an eDNAbased detection method for a Cyprinidae species, Hemigrammocypris rasborella, and applied it in natural habitats. First, we tested our method in 11 irrigation ponds for which information on the distribution of H. rasborella was available. The eDNA detection results matched completely with the known presence/absence data. Next, we applied this method to 81 irrigation ponds for which no distribution information was available, and detected the eDNA of H. rasborella in 6 ponds. Subsequently, we conducted capture surveys in the 6 eDNA-positive ponds and found the species in 5 ponds. These results suggest that eDNA analysis is useful for the monitoring of rare species.Tohoku University, 2016, Japanese Journal of Ecology, 66(3) (3), 613 - 620, Japanese[Refereed]Scientific journal
- PREMISE OF THE STUDY: The evolutionary shift from radial to bilateral symmetry in flowers is generally associated with the evolution of low flower-size variation. This phenomenon supports the hypothesis that the lower size variation in bilateral flowers can be attributed to low pollinator diversity. In this study, we propose two other hypotheses to explain low flower-size variation in bilateral symmetrical flowers. To test the three hypotheses, we examined the relative importance of pollinator diversity, composition, and bilateral symmetry itself as selective forces on low flower-size variation. METHODS: We examined pollinator diversity and composition and flower-size variation for 36 species in a seminatural ecosystem with high bee richness and frequent lepidopteran visitation. KEY RESULTS: Bilateral flowers were more frequently visited than radial flowers by larger bees, but functional-group diversity of the pollinators did not differ between symmetry types. Although bilateral flowers had significantly lower flower-size variation than radial flowers, flower-size variation did not vary with pollinator diversity and composition but was instead related to bilateral symmetry. CONCLUSIONS: Our results suggest that the lower size variation in bilateral flowers might have evolved under selection favoring the control of pollinator behavior on flowers to enhance the accurate placement of pollen on the body of the pollinator, independent of pollinator type. Because of the limited research on this issue, future work should be conducted in various types of plant-pollinator communities worldwide to further clarify the issue.Last, BOTANICAL SOC AMER INC, Dec. 2015, AMERICAN JOURNAL OF BOTANY, 102(12) (12), 2032 - 2040, English[Refereed]Scientific journal
- PREMISE OF THE STUDY: Sexual floral dimorphism may have evolved under pollinator-mediated natural selection by which female and male functions are differently influenced. We hypothesized that mating success is differently influenced by display size between sexes, under which sexual dimorphism in flowering schedule has evolved in dioecious species. METHODS: We examined sexual dimorphism in the total number of flowers per shoot, maximum daily display size, longevity of individual flowers, and flowering synchrony (maximum proportion of open flowers) in three dioecious Ilex species (I. pedunculosa, I. serrata, and I. crenata) whose female flowers are not smaller than male flowers. We compared pollinator response to natural variation of daily display size between sexes. We also examined the effect of display size on female and male success (fruit set and pollen deposition and removal). KEY RESULTS: In the three species, male shoots produced significantly more flowers than female shoots did. Although female flowers lasted longer and opened more synchronously than male flowers, maximum daily display size was larger on male shoots than on female shoots. Fruit set was significantly pollen-limited in the field in all species. Pollen deposition and/or fruit set increased with female display size, whereas pollen removal decreased or was approximately constant with male display size in the three species. CONCLUSIONS: We suggest that sexual dimorphism in floral longevity and flowering synchrony might enhance both female and male success in relation to the display size-mating success (pollinator attraction) association irrespective of flower size dimorphism.Last, BOTANICAL SOC AMER INC, Jul. 2015, AMERICAN JOURNAL OF BOTANY, 102(7) (7), 1187 - 1197, English[Refereed]Scientific journal
- QuestionsAre there positive edge effects on beta- and alpha-diversity of plant species across semi-natural grassland-secondary forest gradients located within a traditional agricultural landscape? Is beta-diversity (dissimilarity in plant species composition between two given plots) well explained by environmental differences for both grasslands and forests? Do gradients of environmental factors created by forest edges influence spatial variation in alpha-diversity from edges to grasslands and forests? LocationSemi-natural grasslands and secondary forests (or conifer plantation) around paddy fields in a traditional agricultural landscape, western Japan. MethodsVegetation survey and environmental (soil water content and sunlight) measurements were conducted on 11 transects passing through grassland-forest ecosystems. Spatial variations in plant beta- and alpha-diversity and environmental variables and their relationships were examined. ResultsWe quantitatively demonstrated common positive edge effects on beta-diversity in both grasslands and forests. Our results suggest that among-edge variations in light conditions, which likely depend on edge aspect and forest type, promote high grassland plant beta-diversity in the vicinity of edges. However, the high beta-diversity of forest floor communities in the proximity of edges cannot be explained by this mechanism. Alpha-diversity tended to be lower within grassland plots located around edges than in grassland interiors, while the richness of the forest community increased toward the edge. This alpha-diversity pattern was suggested to be attributable to resource gradients created by the forest edges. ConclusionsAlthough plant alpha-diversity may not be consistently high in the vicinity of edges, beta-diversity in the communities bordering grassland-forest edges will generally be high in the traditional agricultural landscape. Thus, maintenance of environmental heterogeneity among grassland-forest edges in agricultural ecosystems should be prioritized for local biodiversity conservation.WILEY-BLACKWELL, Jul. 2015, APPLIED VEGETATION SCIENCE, 18(3) (3), 493 - 502, English[Refereed]Scientific journal
- Springer Science $\mathplus$ Business Media, Apr. 2015, Theor Ecol, 9(1) (1), 15 - 25, English[Refereed]Scientific journal
- 1. To prevent the invasion of exotic species causing a decline in an endangered endemic species, it is important to determine the distribution of both species at an early stage, when the density of the exotic species is still low, and to manage the invasion immediately. However, distinguishing between closely related species is difficult because they share similar characteristics. 2. The identification of DNA fragments sampled from a body of water (environmental DNA) has become a popular technique for rapidly determining the distribution of a target species. In this study, we analysed environmental DNA in water samples from 37 sites across the Katsura River basin in Japan. We used TaqMan real-time PCR to distinguish the Japanese giant salamander Andrias japonicus from the closely related Chinese giant salamander Andrias davidianus, which is known to invade Japanese rivers and hybridize with the Japanese species. 3. In environmental samples, we detected mtDNA of the endemic species at 25 sites and mtDNA of the exotic species at nine sites. The DNA detection sites were concentrated in the upstream region. The exotic species DNA was found beyond the limits of an earlier capturing survey. 4. Synthesis and applications. Using environmental DNA to monitor the two salamander species requires less time and effort than traditional surveys, so a wide-ranging survey can be conducted rapidly. Our results showed that performing three environmental DNA surveys for each site between autumn and winter is desirable for giant salamanders. Further collection of environmental DNA, in combination with conventional population surveys, will provide valuable information that can help protect rare endemic species in a variety of aquatic ecosystems and can help monitor the invasion of exotic species.WILEY-BLACKWELL, Apr. 2015, JOURNAL OF APPLIED ECOLOGY, 52(2) (2), 358 - 365, English[Refereed]Scientific journal
- Summary: Although traditional land-use and management practices are known to enhance environmental heterogeneity in agricultural lands, loss of heterogeneity resulting from recent land-use changes can lead to spatiotemporal β-diversity losses (biotic homogenization). However, patterns and causes of β-diversity loss, especially at a within-field scale, have remained unexplored. We examined β-diversity declines in plants, butterflies and orthopterans resulting from land abandonment and intensification in semi-natural grasslands on paddy margins at a within-field scale in relation to changes in disturbance frequency and surrounding landscapes by surveying eight abandoned, thirteen traditional and ten intensive paddy terraces. Three indices, the additive partitioning of species richness (βadd) and the turnover (βtu) and nestedness (βne) components of Jaccard dissimilarity of plants and herbivores, were used to evaluate different aspects of β-diversity. We hypothesized that biotic homogenization due to abandonment and intensification would be expressed as low spatiotemporal βadd and βtu, low spatial βne and high temporal βne. The spatial and temporal βadd of plants and herbivores were higher in traditional terraces than in others. Changes in mowing frequency caused direct declines in butterfly βadd and indirectly decreased herbivore βadd through diminished plant βadd in abandoned and intensified terraces. Neighbouring forests increased plant spatial and butterfly temporal βadd and βtu. Abandoned terraces had higher orthopteran spatial and plant temporal βtu than traditional terraces. Mowing frequency generally did not influence spatial and temporal βtu of plants and herbivores. In intensive terraces, temporal βne of plants were higher than in traditional terraces, suggesting dominance by plant species sharing similar phenologies. Synthesis and applications. These results suggest that traditional mowing practices are essential for maintaining plant and herbivore βadd, and consequently, species pools within terraces. The higher spatial or temporal species turnover of plants and orthopterans in abandoned terraces and higher temporal plant nestedness in intensive than in traditional terraces were not due to increases in species pools within terraces. Because within-terrace environmental heterogeneity is thought to remain in abandoned and intensive terraces, we recommend reduction in mowing frequency in intensive terraces and reintroduction of mowing in abandoned terraces for biodiversity restoration. These results suggest that traditional mowing practices are essential for maintaining plant and herbivore βadd, and consequently, species pools within terraces. The higher spatial or temporal species turnover of plants and orthopterans in abandoned terraces and higher temporal plant nestedness in intensive than in traditional terraces were not due to increases in species pools within terraces. Because within-terrace environmental heterogeneity is thought to remain in abandoned and intensive terraces, we recommend reduction in mowing frequency in intensive terraces and reintroduction of mowing in abandoned terraces for biodiversity restoration.Last, Blackwell Publishing Ltd, 2015, Journal of Applied Ecology, 52(4) (4), 1033 - 1043, English[Refereed]Scientific journal
- Declines in plants and herbivorous insects due to land use abandonment and intensification have been studied in agricultural areas worldwide. We tested four hypotheses, which were complementary rather than mutually exclusive, to understand the mechanisms driving biodiversity declines due to abandonment and intensification. These predict that biodiversity decline is caused by a decline in resource diversity, changes in disturbance regime, surrounding landscape conversion, and a decrease in biomass production. We compared plant richness and butterfly and orthopteran richness and diversity among three land use types in seminatural grasslands: abandoned, traditional, and intensified terraces. Then, we examined effects of changes in resource (plant) richness, frequency of disturbance (mowing), and surrounding landscapes on butterfly and orthopteran diversity to understand the mechanisms driving decline after land abandonment and intensification. Plant and herbivore richness and diversity were significantly lower in abandoned and intensified grasslands than in traditional grasslands. This trend was consistent throughout the seasons in both years of the study. Changes in mowing frequency and surrounding landscape explained plant richness declines as a consequence of land abandonment and intensification. Declines in herbivorous insects were explained by plant richness declines and changes in mowing frequency, but not by landscape changes. Plant and herbivore richness were maximized at an intermediate mowing frequency (approximately twice per year), which is typical practice on traditional terraces. This is the first report demonstrating that the intermediate disturbance hypothesis explained well the biodiversity declines in agricultural ecosystems. The richness and diversity responses of herbivore functional groups to plant richness, mowing frequency, and surrounding landscapes were generally inconsistent with predictions. We found significant trends in which butterfly and orthopteran species with low abundance in traditional terraces were lost in abandoned and/or intensive terraces. This may suggest that the number of individuals of most herbivorous species decreased randomly with respect to life-history traits following a decline in plant richness after changes in disturbance frequency. This study demonstrates that declines in herbivorous insects can be explained by multiple factors, and provides a unified explanation for biodiversity declines in both abandoned and intensified use of agricultural lands, which have often been studied separately.Last, WILEY, Nov. 2014, ECOLOGICAL MONOGRAPHS, 84(4) (4), 637 - 658, English[Refereed]Scientific journal
- Although land-use changes such as urbanization have dramatically altered plant-pollinator interactions, little is known about their effects on pollen limitation and floral traits. In this study, we examined pollinator visit frequency, reproductive success, and floral trait measurements in 12 populations of the annual andromonoecious Commelina communis in an urban-rural area Pollinator and mate availability decreased significantly with developed land area around the study site. Most urbanized populations suffered from significant pollinator-limited male and/or female reproductive success. High fruit set in urbanized populations may suggest the presence of high reproductive assurance by selfing. The stigma height and degree of herkogamy significantly decreased with increased pollinator limitation. Petal length, anther height, and/or the pollen : ovule ratio tended to be low in pollinator- and mate-limited urban populations. One urban population with high pollinator availability had flowers with higher herkogamy and stigma height compared to rural populations. These results suggest that urbanization may provide diverse selective forces that could affect the phenotypic variation in floral traits.UNIV CHICAGO PRESS, Aug. 2014, AMERICAN NATURALIST, 184(2) (2), 258 - 267, English[Refereed]Scientific journal
- Last, 関西自然保護機構, Jan. 2014, 地域自然史と保全, 35(1) (1), 115 - 123, Japanese兵庫県西谷地区における準絶滅危惧種スズサイコVincetoxicum pycnostelma Kitag.の繁殖特性及び訪花昆虫相[Refereed]Scientific journal
- Although several studies have demonstrated that disturbance contributes to species' diversity, little emphasis has been placed on the identification of species' coexistence mechanisms related to life history traits. In this study, we compared species' richness and components of plant communities around river confluences to explore how disturbance promotes the coexistence of species with different life history traits. Sites upstream and downstream of confluences are ideal for such comparisons because they draw on the same species' pools and have similar ambient conditions, but differ markedly in the extents of flooding disturbance. We compared sites upstream and downstream of confluences by calculating species' richness and community similarity indices for several life history traits in both summer and spring. In summer, the combined richness of all the species, of annual- and summer-flowering species, was higher downstream from confluences than upstream, but this was not the case for perennials. Similarity analyses suggested that plant communities are constructed according to a neutral process, whereby interactions between the coexisting species are neutral. However, in spring, species' richness was similar upstream and downstream of confluences for all life history traits. Similarity analyses suggested that under these circumstances, the communities were constructed through a species-sorting process i.e., each life history trait had a distinct habitat preference. Thus, the relative strengths of different community assembly processes may change seasonally. We concluded that species groups differing in their responses to disturbance may coexist in a single community. Thus, community structuring following disturbance may involve two processes: a neutral and a species-sorting process. The relative importance of each may vary between species' life history traits and between seasons, and the interaction may account for current community structures. © 2014 Springer Science+Business Media Dordrecht.Last, Kluwer Academic Publishers, 2014, Plant Ecology, 215(6) (6), 597 - 612, English[Refereed]Scientific journal
- Examining the causes of interspecific differences in susceptibility to bidirectional land-use changes (land abandonment and use-intensification) is important for understanding the mechanisms of global biodiversity loss in agricultural landscapes. We tested the hypothesis that rare (endangered) plant species prefer wet and oligotrophic areas within topography- and management-mediated resource (soil water content, nutrient, and aboveground biomass) gradients, making them more susceptible to both abandonment and use-intensification of agricultural lands. We demonstrated that topography and management practices generated resource gradients in seminatural grasslands around traditional paddy terraces. Terraced topography and management practices produced a soil moisture gradient within levees and a nutrient gradient within paddy terraces. Both total and rare species diversity increased with soil water content. Total species diversity increased in more eutrophied areas with low aboveground biomass, whereas rare species diversity was high under oligotrophic conditions. Rare and common species were differentially distributed along the human-induced nutrient gradient, with rare species preferring wet, nutrient-poor environments in the agricultural landscapes studied. We suggest that conservation efforts should concentrate on wet, nutrient-poor areas within such landscapes, which can be located easily using land-use and topography maps. This strategy would reduce the costs of finding and conserving rare grassland species in a given agricultural landscape.ECOLOGICAL SOC AMER, Sep. 2013, ECOLOGICAL APPLICATIONS, 23(6) (6), 1357 - 1366, English[Refereed]Scientific journal
- 2013, Behaviour, 150(1) (1), 103 - 114, EnglishScientific journal
- Springer Science and Business Media LLC, Jun. 2012, Conservation Genetics Resources, 4(2) (2), 495 - 497, English[Refereed]Scientific journal
- Wiley, Jan. 2012, New Phytologist, 193(1) (1), 196 - 203, English[Refereed]Scientific journal
- Major drivers of amphibian declines via urbanization include land-use changes that cause loss, fragmentation, splits, and degradation of habitat. The effects of these changes in habitat conditions on the persistence of populations are expected to differ among species depending on their dispersal habits: species with strong site fidelity would likely be more affected by habitat loss and degradation, whereas species with highly dispersive habits would be more threatened by habitat fragmentation and split (the dispersal-dependent-decline hypothesis). To test this hypothesis, we examined the distribution patterns of two paddy-associated frog species (Pelophylax nigromaculatus and Hyla japonica) with different dispersal habits along a rural-urban gradient of the Osaka-Kobe metropolitan area, Japan. Our results partially support the dispersal-dependent-decline hypothesis in that the species with strong site fidelity, i.e., P. nigromaculatus, was threatened by habitat-area (agricultural field) decline and habitat-quality degradation (prevalence of concrete levees) rather than by habitat fragmentation. To the best of our knowledge, our study is the first report that suggests paddy-associated amphibian declines via urbanization in the Asian region. However, the second half of the hypothesis, i.e., that the dispersive species (H. japonica) would be more strongly affected by habitat fragmentation via roads and habitat split via declines in surrounding forests was not supported. The lack of support for this portion of the hypothesis may be due to the high adaptability of H. japonica to artificial landscapes. We discuss the value of the dispersal-dependent-decline hypothesis for conservation planning in agricultural lands of urban areas. (C) 2011 Elsevier B.V. All rights reserved.Corresponding, ELSEVIER SCIENCE BV, Dec. 2011, LANDSCAPE AND URBAN PLANNING, 103(3-4) (3-4), 318 - 325, English[Refereed]Scientific journal
- Species-occurrence data sets tend to contain a large proportion of zero values, i.e., absence values (zero-inflated). Statistical inference using such data sets is likely to be inefficient or lead to incorrect conclusions unless the data are treated carefully. In this study, we propose a new modeling method to overcome the problems caused by zero-inflated data sets that involves a regression model and a machine-learning technique. We combined a generalized liner model (GLM). which is widely used in ecology, and bootstrap aggregation (bagging), a machine-learning technique. We established distribution models of Vincetoxicum pycnostelma (a vascular plant) and Ninox scutulata (an owl), both of which are endangered and have zero-inflated distribution patterns, using our new method and traditional GLM and compared model performances. At the same time we modeled four theoretical data sets that contained different ratios of presence/absence values using new and traditional methods and also compared model performances. For distribution models, our new method showed good performance compared to traditional GLMs. After bagging, area under the curve (AUC) values were almost the same as with traditional methods, but sensitivity values were higher. Additionally, our new method showed high sensitivity values compared to the traditional GLM when modeling a theoretical data set containing a large proportion of zero values. These results indicate that our new method has high predictive ability with presence data when analyzing zero-inflated data sets. Generally, predicting presence data is more difficult than predicting absence data. Our new modeling method has potential for advancing species distribution modeling. (C) 2011 Elsevier B.V. All rights reserved.Last, ELSEVIER SCIENCE BV, Sep. 2011, ECOLOGICAL INFORMATICS, 6(5) (5), 270 - 275, English[Refereed]Scientific journal
- An individual of modular organisms, such as plants and fungi, consists of more than one module that is sometimes physically and physiologically connected with each other. We examined effects of translocation costs, resource-fitness relationships and original resource conditions for modules on the optimal resource translocation strategy for reproductive success in modular organisms with simple models. We considered two types of translocation cost: amount-dependent and ratio-dependent costs. Three optimal resource translocation strategies were recognized: all resource translocation (ART), partial resource translocation (PRT), and no resource translocation (NRT). These strategies depended on the translocation cost, shape of resource-fitness curve, and original resource condition for each module. Generally, a large translocation cost and a concave resource-fitness relationship promoted NRT or PRT. Meanwhile, a small translocation cost and convex resource-fitness relationship facilitated ART. The type of translocation cost did not strongly affect the optimal resource translocation patterns, although ART was never an optimal strategy when the cost was ratio-dependent. Resource translocation patterns found in modular plants were discussed in the light of our model results.SPRINGER, Jul. 2011, EVOLUTIONARY ECOLOGY, 25(4) (4), 885 - 898, English[Refereed]Scientific journal
- 1. While flooding creates diverse habitats for plants and animals in riparian ecosystems, it presents a nuisance to human settlement. Thus, such areas that are frequently disturbed by flooding are more likely to experience strong artificial control measures. 2. This hypothesis was tested and a method was developed to identify these areas using river maps. The effects of two terrain components that could potentially influence flooding frequency (the number of confluences and the degree of meandering per unit area) on both the distribution of threatened species and the degree of artificial modification were examined at two different scales (grid sizes) using two riparian data sources. 3. The numbers of threatened plant species and artificial constructions increased with the number of confluences and the degree of meandering per unit area. The number of threatened plant species was not correlated with the number of artificial constructions. 4. In addition, the results suggest that confluences and meanderings provide different habitat conditions for threatened plant species. Confluences may provide more frequently disturbed habitats, whereas meanderings may provide relatively stable habitats. 5. Based on these results, through flooding, both confluences and meanderings are important for creating and maintaining the diverse habitats used by threatened species, but these habitats are also currently threatened by artificial controls. We suggest that a per-unit-area confluence density and river length map is a helpful tool for locating local biodiversity hot spots. The identification of major reservoirs of biodiversity that are currently threatened can improve conservation and management planning. Copyright (C) 2011 John Wiley & Sons, Ltd.Last, WILEY-BLACKWELL, Jun. 2011, AQUATIC CONSERVATION-MARINE AND FRESHWATER ECOSYSTEMS, 21(4) (4), 358 - 363, English[Refereed]Scientific journal
- We studied vegetation changes in a small floating mat bog in Mizorogaike Pond (Kyoto, Japan), which had experienced a severe decrease in the number and area of hummocks caused by nutrient loading in the 1960s and 1970s, to examine whether reducing the extent of nutrient loading can restore degraded wetland vegetation. However, nutrient loading in the region has been minimized since the 1980s. We examined the distributions of hummocks and Sphagnum cuspidatum mats in 1980, 1988, and 2006, as well as nine major vascular plants that dominated the hollows on the floating mat in 1980 and 2006. The total area of normal hummocks formed by Sphagnum palustre increased from 5865.3 m(2) in 1980 to 5913.6 m(2) in 1988 and 8485.2 m(2) in 2006. The total area of the S. cuspidatum mats also changed, from 416.4 m(2) in 1980 to 322.3 m(2) in 1988 and 1012.5 m(2) in 2006. Examination of the spatial distribution patterns of major plants revealed that emergent plants decreased in the northern part of the mat, but increased in the southern part. Thus, the improved pond water quality was effective at restoring hummocks, although nutrient loading may have caused some irreversible changes in the wetland vegetation.Last, Springer Science and Business Media LLC, Dec. 2010, Limnology, 11(3) (3), 289 - 297, English[Refereed]Scientific journal
- Kanasai Organization for Nature Conservation, Dec. 2010, 関西自然保護機構会誌, 32:85-98.(2) (2), 85 - 98, Japanese兵庫県宝塚市西谷地区における里草地の草本植物相.[Refereed]Scientific journal
- Last, Wiley, Nov. 2010, Ecological Research, 25(6) (6), 1161 - 1169, English[Refereed]Scientific journal
- Although dendritic networks within ecosystems have typically been considered a special case of network topology, they have attracted a great deal of attention in recent years. These systems exhibit unique features in that both the nodes and branches provide distinct habitats. Within a river discontinuum context, river confluences, which are nodes of dendritic river networks, are hypothesised to have particular hydrodynamic traits that create heterogeneous habitats through a unique disturbance regime, although this hypothesis has not yet been tested. We tested this hypothesis using a vegetation data set collected from 14 river basin systems in Hyogo Prefecture, Japan. We compared vegetation-patch diversity between confluence and single-flow areas using hierarchical Bayesian models. Our results demonstrated greater vegetation-patch diversity in confluence areas compared to single-flow areas. Our findings support the hypothesis that confluences result in highly heterogeneous habitats. To the best of our knowledge, this is the first empirical report to demonstrate that river confluences have high vegetation-patch diversity. We conclude that network nodes play an important role in maintaining the biodiversity of river networks. © Osawa et al.Last, Bentham Science Publishers Ltd., Jul. 2010, The Open Ecology Journal, 3(1) (1), 48 - 58, English[Refereed]Scientific journal
- Last, Springer Science and Business Media LLC, Jul. 2010, Plant Ecology, 209(1) (1), 95 - 108, English[Refereed]Scientific journal
- Last, Elsevier BV, Feb. 2010, Agriculture, Ecosystems & Environment, 135(4) (4), 304 - 309, English[Refereed]Scientific journal
- Springer Science and Business Media LLC, Jul. 2009, Oecologia, 160(4) (4), 667 - 674, English[Refereed]Scientific journal
- Asymmetry in the competition abilities between invasive and native consumers can potentially influence the colonization success by invasive species. We tested whether a subsidy of allochthonous prey enhanced an asymmetric competition between invasive bluegill (Lepomis macrochirus) and two native cyprinid fish, that is, stone moroko (Pseudorasbora parva) and tamoroko (Gnathopogon elongatus elongatus). A field experiment was conducted using enclosures wherein the strength of interspecific competition and the presence/absence of allochthonous prey were manipulated. The experiment revealed that allochthonous prey alleviated the limitation of fish growths caused by a severe competition for aquatic prey resources. However, the importance of allochthonous prey differed considerably between invasive bluegill and the two native cyprinids. Individual bluegills grew faster when the allochthonous prey was supplied, whereas no difference in growth was observed in the two cyprinids whether or not allochthonous prey was supplied. Interestingly, the importance of allochthonous prey on the total amount of bluegill growth varied depending on the numerical abundance of native cyprinid competitors, and this importance increased when the native cyprinids were abundant. These findings indicated that allochthonous prey provides an asymmetric growth benefit to invasive bluegills over the two native cyprinids by alleviating asymmetrically the competition strength in a Japanese pond, especially under the conditions of severe interspecific resource competition and a limitation in the utilization of in situ prey resources.SPRINGER, Jun. 2009, BIOLOGICAL INVASIONS, 11(6) (6), 1347 - 1355, English[Refereed]Scientific journal
- Lead, The Ecological Society of Japan, 2008, JAPANESE JOURNAL OF ECOLOGY, 58(3) (3), 170 - 172, JapaneseResearch society
- Informa UK Limited, Jan. 2008, Journal of Apicultural Research, 47(4) (4), 296 - 303, English[Refereed]Scientific journal
- We compared the amount of variation in flower size between autogamous and insect-pollinated species to examine the hypothesis that pollinator-mediated selection stabilizes flower size in plant populations. One would expect the flower size variation to be larger in selfing species that are less affected by pollinator-mediated stabilizing selection than in insect-pollinated species. The results of phylogenetic comparisons between autogamous and insect-pollinated flowers supported the pollinator-mediated stabilizing selection hypothesis, although the non-phylogenetic comparison did not. According to our results, we discuss the factors influencing the flower size variation.Feb. 2007, Nordic Journal of Botany, 24(5) (5), 593 - 598, English[Refereed]Scientific journal
- Wiley, Feb. 2007, American Journal of Botany, 94(2) (2), 249 - 258, English[Refereed]Scientific journal
- A valuable source of vegetation occurs on a floating mat consisting of sphagnum peat in Mizorogaike Pond (Kyoto, Japan). To clarify the effects of sika deer on the floating mat, we used motion-sensor cameras to photograph sika deer in 2005. We obtained 33 pictures of sika deer, most taken at night. We established a 1×1600 m belt transect and investigated the spatial distribution of plant species and feeding scars. Fourteen herbaceous plants had feeding scars from sika deer ; Menyanthes trifoliata and Iris laevigata had feeding scars in 50% or more of the sub-transects (1×10 m, N = 160). We suggest that sika deer use the entire floating mat for feeding because feeding scars on M. trifoliata, I. laevigata, and Isachne globosa were ubiquitous. These dominant species had feeding scars in 10% or more of the sub-transects. Sika deer are considered ecosystem engineers ; severe feeding pressure by sika deer may change the vegetation in the Mizorogaike Wetland. To conserve the Mizorogaike Wetland, a deer exclosure fence must be established, and vegetation and deer effects, as well as water quality effects, in the Mizorogaike Wetland must be studied.The Ecological Society of Japan, 2007, Japanese journal of conservation ecology, 12(1) (1), 20 - 27, Japanese[Refereed]
- 2007, 保全生態学研究, 12:20-27., Japanese深泥池湿原へのニホンジカの侵入と植生に対する採食圧[Refereed]Scientific journal
- Wiley, Aug. 2006, Functional Ecology, 20(4) (4), 585 - 591, English[Refereed]Scientific journal
- 科学・技術が高度に発達した社会において、(a)環境問題等の解決手段として、(b)知的探求活動として、市民の科学・技術にかかわる問題の調査・研究能力を高めてゆくこと(エンパワーメント)が大きな意味を持つ。我々は、神戸大学大学院総合人間科学研究科に設置された発達支援インスティテュート/ヒューマン・コミュニティ創成研究センターの研究プロジェクトとして「市民科学に対する大学の支援に関する実践的研究」の取り組みを始めた。本プロジェクトは、神戸を主なフィールドとして、幅広い年齢や素養をもつ市民が、大学の支援のもとに、科学リテラシーを高めるとともに、自らが調査・研究能力を獲得してゆく持続可能なシステムとそれを担う組織、人材のあり方を実践的に探り、日本の社会に適したモデルを構築することを目指す。Japan Society of Science Education, Sep. 2005, 科教研報, 20・2, 47-51(2) (2), 47 - 51, JapaneseScientific journal
- Why do bilaterally symmetrical flowers orient vertically? Flower orientation influences pollinator landing behaviourFlower orientation is an important character influencing plant fitness. Zygomorphic flowers are known to orient vertically. We conducted field experiments in which we changed the flower angle of zygomorphic Commelina communis to determine how flower orientation affects pollinator behaviour. We confirmed that Commelina flowers oriented vertically like other zygomorphic flowers. Then, we artificially prepared control, upward- and downward-oriented flowers and exposed them to natural pollinators (syrphid flies and bumblebees). We found that the frequency of approach by syrphid flies and bumblebees was not influenced by flower angle, but there were fewer landings on downward-oriented flowers than on control and upward-oriented flowers. Moreover, the upward flower orientation increased illegitimate landings (landing on the flower without touching the stigmas or mating-related anthers) compared with controls. Thus, vertical flower orientation in zygomorphic flowers serves to control pollinator landings. Our findings suggest that deviations from vertical orientation may reduce fitness in C communis by reducing the efficiency of insect-mediated pollen transfer.EVOLUTIONARY ECOLOGY LTD, Jan. 2005, EVOLUTIONARY ECOLOGY RESEARCH, 7(1) (1), 151 - 160, English[Refereed]Scientific journal
- Difference in web construction behavior at newly occupied web sites between two Cyclosa speciesAnimals make decisions based on subjective assessments of their environment. To determine their future foraging activities, animals probably assess food availability from past foraging experiences. Thus, foraging also functions as a way for animals to collect information, with the uncertainty of an assessment decreasing as foraging activity increases. This suggests that different needs for a correct assessment may affect the investment made in foraging activities. Orb-web spiders sometimes relocate their webs and relocation rate differs among species. After web relocation, several spider species have been reported to construct the first webs at newly occupied web sites using less silk than usual, possibly to avoid the risk of an overinvestment at sites where food availability has not been determined. Nevertheless, they may pay a cost, because of inadequate decision-making, if webs constructed with less silk convey less information and increase the uncertainty of an assessment. We expect that stronger site tenacity necessitates a greater requirement for correct assessment of web site and the degree to which spiders reduce the amount of web silk in the first web after web relocation is smaller in species that use the same site longer. To test this hypothesis, we examined web construction in two orb-web spiders, Cyclosa octotuberculata and C. argenteoalba. At the same time we found that these two species exhibit different web-site tenacity, as C. octotuberculata does not relocate its webs as frequently as does C. argenteoalba. After artificially induced web relocation, C. argenteoalba constructed webs that were initially smaller and contained only about 2/3 of the silk in control webs that were constructed at the original site. In contrast, C. octotuberculata did not exhibit such decreases in web size or in the amount of web silk used. This result is consistent with our hypothesis.BLACKWELL VERLAG GMBH, May 2004, ETHOLOGY, 110(5) (5), 397 - 411, English[Refereed]Scientific journal
- We compared the amount of variation in flower size between autogamous and insect-pollinated species to examine the hypothesis that pollinator-mediated selection stabilizes flower size in plant populations. One would expect the flower size variation to be larger in, selfing species that are less affected by pollinator-mediated stabilizing selection than in insect-pollinated species. The results of phylogenetic comparisons between autogamous and insect-pollinated flowers supported the pollinator-mediated stabilizing selection hypothesis, although the non-phylogenetic comparison did not. According to our results, we discuss the factors influencing the flower size variation.WILEY-BLACKWELL, 2004, NORDIC JOURNAL OF BOTANY, 24(5) (5), 593 - 598, English[Refereed]Scientific journal
- Wiley, Dec. 2003, Plant Species Biology, 18(2-3) (2-3), 103 - 106, English[Refereed]Scientific journal
- Effect of floral organ sizes on female reproductive success in Erythronium japonicum (Liliaceae)We examined the effects of floral organ size on female reproductive success in self-incompatible Erythronium japonicum. We measured tepal size and anther-stigma separation and investigated the relationship between these measurements and fruiting and seeding success. We found that tepal length was positively correlated with fruiting success and the number of seeds per fruit. This suggests that pollinator attraction is affected by tepal length in E. japonicum and that the number of pollinator visits affects female reproductive success. Anther-stigma separation was the most variable floral trait measured and was not correlated with either fruiting or seeding success in this species, suggesting that the proportion of outcross pollen deposited on stigmas by pollinators does not increase with anther-stigma separation. This is inconsistent with a previous report on Etyyhtonium. grandiflorum. Pollinator size might explain this interspecific difference in the effect of anther-stigma separation on female reproductive success.BOTANICAL SOCIETY OF KOREA, Dec. 2003, JOURNAL OF PLANT BIOLOGY, 46(4) (4), 245 - 249, English[Refereed]Scientific journal
- Variation in floral organ size depends on function: a test with Commelina communis, an andromonoecious speciesWe measured the size of floral organs in andromonoecious Conirnelina communis to test the hypothesis that pollinator-mediated selection might regulate variation in the size of floral organs. We compared variation in floral organ size between C. communis perfect flowers, with fertile pistils, and C. communis staminate flowers, with sterile pistils. We hypothesized that variation in size of the sexually functionless pistil would be large. We found supporting evidence from eight C. communis populations. These results suggest that pollinator-mediated selection may have stabilized variation in the style length of perfect flowers. We also found differences in variation in length among three different types of anthers in both perfect and staminate flowers, only two of which produce fertile pollen. This is consistent with our prediction that mating-related organs should vary less in size than attraction-related organs.EVOLUTIONARY ECOLOGY LTD, May 2003, EVOLUTIONARY ECOLOGY RESEARCH, 5(4) (4), 615 - 622, English[Refereed]Scientific journal
- Using past experience in web relocation decisions enhances the foraging efficiency of the spider Cyclosa argenteoalbaThe purpose of this study is to test whether the integration of past and present foraging experience in web relocation decision enhances foraging efficiency of the spider Cyclosa argenteoalba in its natural environment. We measured daily changes in the prey availability at several fixed sites in a natural environment and constructed a model environment based on these observational data. In the model environment, we simulated the behavior of spiders that foraged and relocated their webs according to several decision rules, which differed in terms of how a spider used its past experience. Results of the simulation revealed that the less past experience is discounted in making web relocation decisions, the more prey the spider is expected to capture. The expected number of web relocations decreased as spiders kept past foraging experience longer. These results suggest that C. argenteoalba enhances foraging efficiency by using past foraging experience for long times in the decision of web relocation in its natural environment.KLUWER ACADEMIC/PLENUM PUBL, May 2003, JOURNAL OF INSECT BEHAVIOR, 16(3) (3), 371 - 380, English[Refereed]Scientific journal
- Monitoring dynamics of beech forests with different structure in Shirakami Mountains(
Conservation and sustainable utilization of forests in Shirakami Mountains. -I. Distribution and dynamics of forests in and around Shirakami Mountains.-) Forest dynamics and regeneration were monitored for three beech stands with different forest structure in the core area of World Natural Heritage at Shirakami Mountains. The parameters showing forest structure (tree density, basal area, diameter distributions etc.), dynamic parameters (recruitment and mortality of trees) and those relating regeneration (seed production, seedling emergence etc.) were different among stands, suggesting their different histories of establishment. The relationships between stands along forest development process were estimated with the dynamic parameters obtained. The necessary accuracy and resolution for the monitoring are also discussed with the basis of experiencing the observation.The Tohoku Society of Forest Science, 2003, Tohoku journal of forest science, 8, 67 - 74, Japanese[Refereed]Scientific journal - The evolution of flower allometry in selfing speciesAllometric relationships of floral organs were compared in related outcrossing (herkogamous) and selfing (autonomously self-pollinated) species in the genera Mazus and Hosta to determine how floral traits have evolved under selection favouring autonomous self-pollination. Autogamous Scutellaria dependens was also examined. We measured several floral traits in the five species. Selfing species had a steeper slope of the log-log regression and correlation coefficient for the filament-stigma height relationship than related outcrossing species. In three selfing species, the filament-stigma correlation was stronger than the petal-filament and petal-stigma correlations. Outcrossing species had weaker filament-stigma correlations than the other correlations. These findings suggest that, in selfing species, the placement of the stigma close to the anthers has evolved under selection favouring autogamy and that filament-stigma correlations might have evolved together with mating-system evolution in flowering plants.EVOLUTIONARY ECOLOGY LTD, Dec. 2002, EVOLUTIONARY ECOLOGY RESEARCH, 4(8) (8), 1217 - 1227, English[Refereed]Scientific journal
- We investigated floral size variation and the relationship between floral display and pollinator and predispersal seed predator attraction in an achlorophyllous, myco-heterotrophic plant, Monotropastrum globosum. We found substantial variation in flower size in this species, similar to reports for other myco-heterotrophic plants. We examined the effects of flower size and number on female reproductive success by measuring pollination and fruiting success and predispersal seed predation. We found no evidence that pollinators (bumblebees) responded to either flower size or number, but predispersal seed predators (Lepidopteran larvae) preferred plants with larger, more numerous flowers, although predation frequency was not high. Therefore, we did not detect any effect of larger floral displays on female reproductive success in this species. Flower size independent pollination success and low predation pressure might allow the large floral size variation in M. globosum. The percentage of fruiting flowers was lower than that of pollinated flowers and larger flowers tended to set fruit more often than smaller ones, suggesting that fruit set in M. globosum is resource-limited.Dec. 2002, Plant Species Biology, 17(2-3) (2-3), 147 - 153, English[Refereed]Scientific journal
- We conducted a quantitative analysis of geographic color variation in two species of dung beetles: Geotrupes auratus and G. laevistriatus. The reflectance of the dorsal surfaces was measured from 300 to 700 nm using a spectrophotometer. The reflectance curves for both beetles were bimodal; there were two distinct peaks, namely, the a peak, between 400 and 700 nm, and the beta peak at around 300 nm. A stepwise discriminant analysis indicated that geographic color variation in Geotrupes beetles was primarily characterized by a shift of the a peak. Using beetles from three locations, we compared the wavelength (nm) of the alpha peak (lambdamax(alpha)) and its reflectance intensity (R(alpha)) to investigate sex and population differences. Intraspecific geographic variation in coloration was effectively detected by discriminant analysis of spectral reflectance curves. Our results showed that G. auratus and G. laevistriatus had similar coloration within each sampling location. Our study also revealed hidden sex differences in R(alpha); R(alpha) of males were significantly higher than those of females in both species. Since the dorsal surface of the beetles shows remarkable color variation, and coloration can be assessed objectively using reflectance spectra, Geotrupes beetles may be good model organisms to investigate geographic color variation.ZOOLOGICAL SOC JAPAN, Mar. 2002, ZOOLOGICAL SCIENCE, 19(3) (3), 351 - 358, English[Refereed]Scientific journal
- Wiley, Dec. 2001, Plant Species Biology, 16(3) (3), 231 - 235, English[Refereed]Scientific journal
- University of Chicago Press, Nov. 2001, International Journal of Plant Sciences, 162(6) (6), 1307 - 1311, English[Refereed]Scientific journal
- Wiley, Aug. 2001, Nordic Journal of Botany, 21(4) (4), 397 - 399, English[Refereed]Scientific journal
- Elsevier BV, Jun. 1999, Animal Behaviour, 57(6) (6), 1251 - 1255, English[Refereed]Scientific journal
- The reproductive biology of four Japanese Calystegia species (Convolvulaceae) was studied to examine the effects of clonality and population structure on reproductive success. Calystegia soldanella, C. hederacea, and C. japonica are self‐incompatible, while C. sepium is self‐compatible but needs pollinator services for self‐pollination. The showy, bisexual flowers of Calystegia offer pollen and nectar that attract many kinds of insects such as bees and syrphid flies. Clones of C. soldanella often formed mats just above the high tide line on beaches and produced a great number of seeds. Calystegia hederacea and C. japonica were distributed as patches of separate clones and often failed to transfer pollen grains among clones. Fruit and seed sets in C. hederacea and C. japonica were not limited by pollinators but by the number of compatible pollen grains. Although C. sepium clones were also distributed in patches, high and stable fecundity was achieved by self‐compatibility and pollinator attraction. We suggest that self‐compatibility in C. sepium has evolved under fertilization limitation caused by geitonogamy or facilitated selfing.Wiley, Mar. 1999, American Journal of Botany, 86(3) (3), 436 - 446, English[Refereed]Scientific journal
- 2022, 日本生態学会大会講演要旨(Web), 69thVerification of the effectiveness of interval shooting camera in pollinator survey-Comparison with direct observation-
- 2021, 日本生態学会大会講演要旨(Web), 68thEffects of land-use changes on pollination networks and services in paddy ecosystems
- 2021, 日本生態学会大会講演要旨(Web), 68thElucidation of pollinator community in Akana Wetland, Shimane Prefecture, using direct observations and interval shooting cameras
- 2021, 日本生態学会大会講演要旨(Web), 68thInter population floral variation caused by adaptation to local pollination environment.
- 2021, 日本生態学会大会講演要旨(Web), 68thEffects of reproductive interference from closely related species on genetic structure and selfing rate in native Commelina species.
- 2020, 日本生態学会大会講演要旨(Web), 67thCommunity-wide difference in floral traits between continental and oceanic islands-different patterns depending on corolla tube length-
- 2020, 日本生態学会大会講演要旨(Web), 67thSex determination of flowers depending on day length and nutrient environment in andromonoecious species Commelina communis f. ciliata
- 2020, 日本生態学会大会講演要旨(Web), 67thDoes urbanization influence popultion selfing rate in annual herb Commelina communis?
- 2019, 日本生態学会大会講演要旨(Web), 66th送粉ネットワークのジェネラリスト化による送粉機能への影響-都市と島の生態系を例に
- 2019, 日本生態学会大会講演要旨(Web), 66th都市化による植物群集の花色組成変化
- 2019, 日本生態学会大会講演要旨(Web), 66th雄性両全性同株ケツユクサの花の性は資源依存的に決まるのか?
- 2019, 日本生態学会大会講演要旨(Web), 66th送粉環境と花形質が自殖率に与える影響:ツユクサの集団間変異を用いた検証
- 2018, 日本生態学会大会講演要旨(Web), 65th都市化により植物群集の繁殖成功は低下するのか?-開花量減少と送粉者相変化の影響-
- 2018, 日本生態学会大会講演要旨(Web), 65th防鹿柵設置による植生回復が訪花昆虫に与える効果について(大台ヶ原での事例)
- 2018, 日本生態学会大会講演要旨(Web), 65th都市化による種多様性減少は送粉ネットワークのジェネラリスト化を促進するのか?
- 2018, 日本生態学会大会講演要旨(Web), 65th虫媒花における,花色と形態の相関進化-送粉者相の異なる5地域間の比較-
- 2018, 日本生態学会大会講演要旨(Web), 65thケツユクサの花の性決定に関わる遺伝子発現
- 2018, 第65回日本生態学会日本生態学会全国大会賞(ポスター賞)最優秀賞_2
- 2017, 日本生態学会大会講演要旨(Web), 64th都市化による機能群多様性の減少が植物-送粉者ネットワークに与える影響
- 2017, 日本生態学会大会講演要旨(Web), 64th送粉者間の競争の変化がもたらす訪花ニッチの変化と植物への影響:本州と海洋島の比較
- 2017, 日本生態学会大会講演要旨(Web), 64th半自然草地における系統的多様性の均質化-水田畦畔草地における検証
- 2017, 環境情報科学, 46(1) (1)都市緑地が主観的な緑量や満足度に与える影響の分析
- 2016, 日本生態学会大会講演要旨(Web), 63rd低い送粉者の機能的多様性が形態のミスマッチを引き起こす
- 2016, 日本生態学会大会講演要旨(Web), 63rd送粉者機能群多様性と送粉ネットワーク構造の関係
- 2016, 日本生態学会大会講演要旨(Web), 63rd土地利用変化がトノサマガエルの食性に与える影響
- 2016環境科学会2016年会．最優秀発表賞 (富士電機賞)
- 2016, 第63回日本生態学会日本生態学会全国大会賞(ポスター賞)最優秀賞_1
- 2015, 日本生態学会大会講演要旨(Web), 62nd島嶼において送粉者は小型化するのか?-本州と伊豆諸島の比較-
- 2015, 日本生態学会大会講演要旨(Web), 62nd都市水田畦畔における開花高の高い植物の消失
- 2014, 日本生態学会大会講演要旨(Web), 61st送粉者相の異なる島嶼間の送粉ネットワークの比較
- 2013, 日本生態学会大会講演要旨集, 60th花形質から送粉者相は予測できるか?
- 2013, The 59th Ecological Society of Japan and the 5th East Asian Federation of Ecological SocietiesExcellent Poster Award
- Palynological Society of Japan, 23 Aug. 2012, 日本花粉学会会誌, 58, 168 - 168, English369 Finding new links in an alpine pollination network by examining pollen deposited on the insect body surfaces
- Joint editor, 東京化学同人, Mar. 2025, Japanese, ISBN: 9784807920679教養の生態学 : 未来を生きるすべての人の
- Contributor, 生物の適応進化;生物多様性, 化学同人, Mar. 2021, Japanese, ISBN: 9784759811087生態学
- Joint work, 畔の上の草地ー里草地, 築地書館, Feb. 2019, Japanese, ISBN: 9784806715764草地と日本人 : 縄文人からつづく草地利用と生態系
- Contributor, 水田畦畔草地の生物多様性, 講談社, Sep. 2018, Japanese, ISBN: 9784065129524雑草学入門
- Contributor, Grassland biodiversity in Japan: threats, management and conservation., CRC Press, Boca Raton, US., Aug. 2018, English, Under the temperate humid climate of the Holocene in Japan, most vegetation potentially would change into forests by ecological succession. Harsh environments, natural disturbances and or human activities, however, have sustained natural and semi-natural grasslands until today. The grassland types vary, depending on locations and management forms, and the aims of using semi-natGrasslands of the world: diversity, management and conservationScholarly book
- Contributor, 自殖; 有性生殖; 無性生殖, 共立出版, Apr. 2012, Japanese, ISBN: 9784320057777進化学事典
- 築地書館, Feb. 2012, Japanese, ISBN: 9784806714347草地と日本人 : 日本列島草原1万年の旅
- Contributor, ミズオトギリ−14種もの狩蜂が吸蜜に−; モウセンゴケは昆虫の敵か？味方か？．, サンライズ出版, Mar. 2008, Japanese, ISBN: 9784883253579深泥池の自然と暮らし : 生態系管理をめざして
- Supervisor, 技術評論社, May 2007, Japanese, ISBN: 9784774130620進化で読み解くふしぎな生き物 : シンカのかたち
- Contributor, 花標に学ぶ送粉共生系, エヌ・ティー・エス, Aug. 2006, Japanese, ISBN: 4860431316プラントミメティックス : 植物に学ぶ
- Contributor, 両性花における自家和合性と自動的自家受粉の進化, NetLibrary, 1999, Japanese, ISBN: 9784829911396花生態学の最前線 : 美しさの進化的背景を探る
- 第72回日本生態学会, Mar. 2025, Japanese草原でクモはどのように花を利用するか：花上クモ類における植物利用パターン比較Oral presentation
- 第72回日本生態学会, Mar. 2025, Japanese環境DNA分析を用いた水田におけるカエル類の個体数密度と景観要因の関係の解析Oral presentation
- 第72回日本生態学会, Mar. 2025, Japaneseカエル類の体色変異及び模様の適応的意義：鳥類からの捕食の回避機能に着目してOral presentation
- 第72回日本生態学会, Mar. 2025, Japanese絶滅危惧植物が維持される環境の解明：多様な火入れ草原における植生と土壌の比較絶滅危惧植物が維持される環境の解明：多様な火入れ草原における植生と土壌の比較Oral presentation
- 第72回日本生態学会, Mar. 2025, Japanese歴史の古い草原に隠された環境価値（Part2）Public symposium
- 第72回日本生態学会, Mar. 2025, Japanese生態学を社会へ：生態学会編・教養の生態学（仮）を出版します！Public symposium
- 19th Eurasian Grassland Conference, Aug. 2024, EnglishMechanisms for maintaining diversity of threatened plant species in burned grasslands: focusing on soil properties and vegetation height.Oral presentation
- 19th Eurasian Grassland Conference, Aug. 2024, EnglishChanges in network properties influence pollination services in plant-pollinator communities in an East-Asian mega-city areaOral presentation
- Mar. 2024, Japanese多様な都市生育地環境が植物の形質進化と遺伝構造に与える影響：ツユクサを用いた検証
- 第71回日本生態学会, Mar. 2024, Japanese意外と一途なハナアブ：ハナバチ・ハナアブの連続訪花行動の比較から
- 第71回日本生態学会, Mar. 2024, Japanese歴史の古い草原は根茎量が多いか？ ー新しい草原、森林との比較ーPoster presentation
- 第71回日本生態学会, Mar. 2024, Japanese火入れ草原における絶滅危惧植物種の多様性維持機構：土壌特性と植生高に着目してPoster presentation
- 第70回日本生態学会, Mar. 2023, Japaneseオニタビラコ２亜種の都市-里山間における種子散布能力と空間的分布の比較Poster presentation
- 第70回日本生態学会, Mar. 2023, Japanese在来一年生草本ツユクサの形質進化の検証-多様な都市環境に着目して-Poster presentation
- 第70回日本生態学会, Mar. 2023, Japanese10年間での環境変化に伴う水田性カエル類の分布変化 第70回日本生態学会Poster presentation
- 第70回日本生態学会, Mar. 2023, Japanese海浜植物の形態的特徴-スミレとその変種間の比較-Poster presentation
- 第70回日本生態学会, Mar. 2023, Japaneseカンサイタンポポの閉花タイミングにおける性的対立は送粉者制限下で顕著になるPoster presentation
- 第70回日本生態学会, Mar. 2023, Japanese花形態の複雑化が開花密度-繁殖成功関係へもたらす影響Poster presentation
- 第70回日本生態学会, Mar. 2023, Japanese草地再生過程における送粉ネットワークおよび送粉サービスの回復とそのメカニズムPoster presentation
- 第70回日本生態学会, Mar. 2023, Japaneseジェネラリスト送粉者は、個体レベルではスペシャリストであるのか？Poster presentation
- 第70回日本生態学会, Mar. 2023, Japanese植物-送粉者の関係から探る捕食者 クモ類の花上狩場選好性Poster presentation
- 第70回日本生態学会, Mar. 2023, Japaneseカリガネソウの曲がる花茎は雄の繁殖成功を高めるPoster presentation
- 第70回日本生態学会, Mar. 2023, Japanese溶岩上火入れ草原における希少植物の高い多様性Oral presentation
- 第70回日本生態学会, Mar. 2023, Japanese二次林の作業道路に遺存する草原性植物の多様性Oral presentation
- Asian Grassland Conference, Apr. 2022, EnglishLava flows support high diversity of grassland plants including threatened species in a meadow area managed by burningPoster presentation
- Asian Grassland Conference, Apr. 2022, EnglishUrbanized grasslands within fragmented agricultural lands favor species with short gereration times.Oral presentation
- 第69回日本生態学会, Mar. 2022, Japanese丑丸敦史 カンサイタンポポの閉花タイミングにおける性的対立の可能性Poster presentation
- 第69回日本生態学会, Mar. 2022, Japanese都市における在来植物の表現型変異の多様性-一年生草本ツユクサを用いて-Poster presentation
- 第69回日本生態学会, Mar. 2022, Japaneseヤブツバキにおける厚い花筒はメジロによる送粉への適応か？Poster presentation
- 第69回日本生態学会, Mar. 2022, Japaneseスキー場草地での植生再生過程における送粉ネットワーク構造・植物の繁殖成功の変化Poster presentation
- 第69回日本生態学会, Mar. 2022, Japanese送粉者相の違いが開花密度-繁殖成功関係にもたらす影響Poster presentation
- 第69回日本生態学会, Mar. 2022, Japanese圃場整備と耕作放棄が水田畦畔の植物-送粉者ネットワークと送粉サービスに与える影響Poster presentation
- 第69回日本生態学会, Mar. 2022, Japaneseツユクサの先行自家受粉は他殖の機会を減少させうるか？
- 第69回日本生態学会, Mar. 2022, Japaneseスキー場草原の植物種組成に植生履歴が影響するメカニズムPublic symposium
- 第69回日本生態学会、福岡、, Mar. 2022, Japanese圃場整備の植生への影響は立地環境によって異なるNominated symposium
- 第68回日本生態学会, Mar. 2021, Japanese水田生態系における土地利用変化による送粉ネットワーク・送粉サービスへの影響Public symposium
- 第68回日本生態学会, Mar. 2021, Japanese直接観察とインターバル撮影カメラを用いた島根県赤名湿地における訪花昆虫群集の解明Poster presentation
- 第68回日本生態学会, Mar. 2021, Japaneseケツユクサの可塑的な性決定メカニズム：花序内の資源動態に着目してPoster presentation
- 第68回日本生態学会, Mar. 2021, Japanese草原の時間的連続性が地表徘徊性甲虫群集に与える影響Poster presentation
- 第68回日本生態学会, Mar. 2021, Japanese春から初夏におけるナミアゲハの訪花傾向：野外観察と体表花粉の分析Poster presentation
- 第68回日本生態学会, Mar. 2021, Japanese送粉系群集における、送粉者の分類群組成と花形質組成の季節推移Poster presentation
- 第68回日本生態学会, Mar. 2021, Japanese斜面に生育するテンナンショウ属植物の花序はどこを向くのか?
- 第68回日本生態学会, Mar. 2021, Japanese開花密度が繁殖成功に及ぼす影響~放射相称花・左右相称花間の比較~Poster presentation
- 第68回日本生態学会, Mar. 2021, Japanese棚田の圃場整備による外来植物種の侵入が送粉ネットワークに及ぼす影響Poster presentation
- 第68回日本生態学会, Mar. 2021, Japanese水田において圃場整備と耕作放棄が畦畔の植物-送粉者ネットワークに与える影響Poster presentation
- 第68回日本生態学会, Mar. 2021, Japanese多様な都市生育地は一年生草本の表現型の集団間変異を促進するか?Poster presentation
- 第68回日本生態学会, Mar. 2021, Japanese造成されたスキー場の草原性植物の多様性は種子の散布制限の影響を受けるかPoster presentation
- 第68回日本生態学会, Mar. 2021, Japaneseツユクサの花形質の集団間変異は送粉環境への適応か？：野外調査と栽培実験による検証Poster presentation
- 第67回日本生態学会, Mar. 2020訪花者群集の組成に応じた、植物群集の花形質組成
- 第67回日本生態学会, Mar. 2020雄性両全性同株ケツユクサの個花における日長と養分環境依存的性決定
- 第67回日本生態学会, Mar. 2020島根県赤名湿地における花の形質と訪花昆虫群集の関係
- 第67回日本生態学会, Mar. 2020野外観察と花粉分析によるアゲハチョウの訪花行動の解明
- 第67回日本生態学会, Mar. 2020カラスウリの花におけるフリンジ状花弁の適応的意義
- 第67回日本生態学会, Mar. 2020都市域と里山域での自殖率の集団間比較：一年生草本ツユクサを用いて
- 第67回日本生態学会, Mar. 2020水田における土地利用の変化が畦畔の植物-送粉者ネットワークの構造に及ぼす影響
- 第67回日本生態学会, Mar. 2020都市-里山環境傾度で植物の機能形質の種内変異を起こす要因
- 第51回種生物学シンポジウム 宮崎、2019年12月, Dec. 2019, Japanese草原性絶滅危惧種キキョウの繁殖生態—花の咲く向きに着目して—
- Island biology 2019: III International Conference on Island Evolution, Ecology, and Conservation, Jul. 2019, EnglishEvolution of large flowers adapted to small pollinators in oceanic islands.Poster presentation
- Island biology 2019: III International Conference on Island Evolution, Ecology, and ConservationIsland biology 2019: III International Conference on Island Evolution, Ecology, and Conservation, Jul. 2019, EnglishCommunity-wide difference in floral traits between continental and oceanic island coastal plants.Oral presentation
- 第68回日本生態学会, Mar. 2019, Japanese, Domestic conference林縁性草本ホタルカズラの送粉成功における被陰・被覆の影響Poster presentation
- 第66回日本生態学会, Mar. 2019, Japanese, Domestic conference雄性両全性同株植物ツユクサにおける可塑的な雄花生産Oral presentation
- 第68回日本生態学会, Mar. 2019, Japanese, Domestic conference埋土種子の減少と種子散布制限は新しく建設されたスキー場の草原性植物組成を決定するPoster presentation
- 第68回日本生態学会, Mar. 2019, Japanese, Domestic conference放棄畦畔への草刈り再導入による植物多様性の再生ー５年間の再生実験の成果ーPoster presentation
- 第68回日本生態学会, Mar. 2019, Japanese, Domestic conference都市化は植物の機能形質を変化させるか？阪神地区の水田における検証Poster presentation
- 第68回日本生態学会, Mar. 2019, Japanese, Domestic conference都市化による植物群集の花色組成変化Poster presentation
- 第68回日本生態学会, Mar. 2019, Japanese, Domestic conference地域的攪乱レジームが種プールの対攪乱応答を変化させるPoster presentation
- 第68回日本生態学会, Mar. 2019, Japanese, Domestic conference送粉環境と花形質が自殖率に与える影響：ツユクサの集団間変異を用いた検証Poster presentation
- 第67回日本生態学会, Mar. 2019, Japanese, Domestic conference送粉ネットワークのジェネラリスト化による送粉機能への影響ー都市と島の生態系を例にOral presentation
- 第50回種生物学シンポジウム, Dec. 2018, Japanese, Domestic conference雄性両全性同株植物ツユクサにおける花形態の性的二型性：送粉プロセスに着目してPoster presentation
- 第50回種生物学シンポジウム, Dec. 2018, Japanese, Domestic conference自殖の進化は繁殖干渉下の共存を促進するか：個体ベースモデルを用いたシミュレーションPoster presentation
- The 65th Annual Meeting of Ecological Society of Japan, Mar. 2018, English, Sapporo Convention Center, Sapporo, Japan, International conferenceThe impact of biodiversity in river on valuation of urban ecosystem services: the case of Hanshin region using eDNA and the residents' life satisfaction dataOral presentation
- 第64回日本生態学会大会, Mar. 2017, Japanese, 東京、早稲田大学, Domestic conference風媒・風散布の雌雄異株植物スイバの花序構造：性的二型性とメスのジレンマPoster presentation
- 第64回日本生態学会大会, Mar. 2017, Japanese, 東京、早稲田大学, Domestic conference都市化による機能群多様性の減少が植物‐送粉者ネットワークに与える影響Poster presentation
- 第64回日本生態学会大会, Mar. 2017, Japanese, 東京、早稲田大学, Domestic conference地域的な攪乱頻度に応じた種プールの構築Poster presentation
- 第64回日本生態学会大会, Mar. 2017, Japanese, 東京、早稲田大学, Domestic conference植生履歴が植物相形成に与える影響Poster presentation
- 第64回日本生態学会大会, Mar. 2017, Japanese, 東京、早稲田大学, Domestic conference自然環境と満足度～都市の生活と生態系サービス～Poster presentation
- 第64回日本生態学会大会, Mar. 2017, Japanese, 東京、早稲田大学, Domestic conference耕作放棄地における管理の再導入による植物種の多様性の再生―機能形質による再生プロセ スの解明に向けて―Poster presentation
- The 64th Annual Meeting of Ecological Society of Japan, Mar. 2017, Japanese, Waseda University, Tokyo, Japan, Domestic conferenceEvaluation of a species distribution model based on environmental DNA analysis - An case study of Japanese giant salamander (Andrial japonicus) -Oral presentation
- 第64回日本生態学会大会, Mar. 2017, Japanese, 東京、早稲田大学, Domestic conference花の空間分布が送粉者および捕食者の分布に与える影響Poster presentation
- The 81st Annual Meeting of Japanese Society of Limnology, Nov. 2016, Japanese, Ryukyu University (Okinawa, Japan), Domestic conferenceEvaluation of the species distribution model for Japanese giant salamander based on environmental DNA analysisOral presentation
- Ecological Society of America Annual Meeting 2016, Aug. 2016, English, Fort Lauderdale, Florida, U.S.A., International conferenceEstimating the distribution of the Japanese giant salamander (Andrias japonicus) by ecological niche modeling based on environmental DNA detectionPoster presentation
- Island biology 2016: II International Conference on Island Evolution, Ecology, and Conservation, Jul. 2016, English, Terceira island, Azores, Portugal., International conferenceSpatiotemporal variation in pollinator species and functional diversity influences the structure of pollination networks in Japanese islands[Invited]Oral presentation
- Island biology 2016: II International Conference on Island Evolution, Ecology, and Conservation, Jul. 2016, English, Terceira island, Azores, Portugal., International conferenceLow pollinator functional diversity in oceanic islands influences pollnators’ floral nichesOral presentation
- 第63回日本生態学会大会, Mar. 2016, Japanese, 仙台, Domestic conference風媒の雌雄異株植物スイバの形態に性的二型性はあるかOral presentation
- 第63回日本生態学会大会, Mar. 2016, Japanese, 仙台, Domestic conference土地利用変化がトノサマガエルの食性に与える影響Poster presentation
- 第63回日本生態学会大会, Mar. 2016, Japanese, 仙台, Domestic conference都市化が送粉ネットワークにもたらす影響Poster presentation
- 第63回日本生態学会大会, Mar. 2016, Japanese, 仙台, Domestic conference伝統的管理の実験的導入による里草地再生Poster presentation
- 第63回日本生態学会大会, Mar. 2016, Japanese, 仙台, Domestic conference低い送粉者の機能的多様性が形態のミスマッチを引き起こすPoster presentation
- 第63回日本生態学会大会, Mar. 2016, Japanese, 仙台, Domestic conference送粉者機能群多様性と送粉ネットワーク構造の関係Poster presentation
- 第63回日本生態学会大会, Mar. 2016, Japanese, 仙台, Domestic conference高山帯と低地帯（里草地）で訪花昆虫相・送粉効率は異なるのか？Poster presentation
- The 63rd Annual Meeting of the Ecological Society of Japan, Mar. 2016, Japanese, Sendai International Center, Sendai, Japan, Domestic conferenceA large survey of Japanese giant salamander (Andrias japonicus) by using environmental DNAPoster presentation
- 第63回日本生態学会大会, Mar. 2016, Japanese, 仙台, Domestic conferenceメガシティにおける植物および植食性昆虫の機能的多様性評価Poster presentation
- The 63rd Annual Meeting of the Ecological Society of Japan, Mar. 2016, Japanese, Sendai International Center, Sendai, Japan, Domestic conferenceEnvironmental DNA survey using multiplex PCR for endemic and exotic fish species in the ponds in Hyogo Prefecture[Invited]Nominated symposium
- 第63回日本生態学会大会, Mar. 2016, Japanese, 仙台, Domestic conferenceツユクサ属２品種における雄花生産の季節変化とその要因Poster presentation
- 第63回日本生態学会大会, Mar. 2016, English, 仙台, Domestic conferenceKoki Katsuhara,Atushi Ushimaru,Shumpei Kitamura Functional significance of inconspicuous petals in scent-attracted flowersOral presentation
- 2015 Society of Wetland Scientist Annual Meeting, Jun. 2015, English, Providence, Rhode Island, USA, International conferenceEnvironmental DNA Assessment of Rare Endemic Species and Closely Related Exotic Species: A Case Study of Giant Salamanders in Japan[Invited]Nominated symposium
- 第62回日本生態学会大会, Mar. 2015, Japanese, 鹿児島大, Domestic conference放棄水田畦畔の植物多様性は再生するのか −草刈実験による検討−Poster presentation
- 第62回日本生態学会大会, Mar. 2015, Japanese, 鹿児島大, Domestic conference風媒の雌雄異株植物における開花スケジュールの性的二型性Poster presentation
- 第62回日本生態学会大会, Mar. 2015, Japanese, 鹿児島大, Domestic conference農地管理の違いによる送粉ネットワーク構造の変化Poster presentation
- 第62回日本生態学会大会, Mar. 2015, Japanese, 鹿児島大, Domestic conference同所的に存在するツユクサとケツユクサにおける繁殖干渉の可能性Poster presentation
- 第62回日本生態学会大会, Mar. 2015, Japanese, 鹿児島大, Domestic conference島嶼において送粉者は小型化するのか？ー本州と伊豆諸島の比較ーOral presentation
- 第62回日本生態学会大会, Mar. 2015, Japanese, 鹿児島大, Domestic conference都市水田畦畔における開花高の高い植物の消失Poster presentation
- 第62回日本生態学会大会, Mar. 2015, Japanese, 鹿児島大, Domestic conference都市化による植物および植食性昆虫多様性の減少 －種組成は均質化しているのか－Poster presentation
- 第62回日本生態学会大会, Mar. 2015, Japanese, 鹿児島, Domestic conference都市における花形質の多様化Poster presentation
- 第62回日本生態学会大会, Mar. 2015, Japanese, 鹿児島大, Domestic conference草原面積の縮小が草原性絶滅危惧蝶類の遺伝的多様性に与える影響-標本を用いた過去と現在の比較解析-Poster presentation
- 第62回日本生態学会大会, Mar. 2015, Japanese, 鹿児島大, Domestic conference阪神地区における都市水田の生物多様性ー都市化の影響とその保全ー[Invited]Invited oral presentation
- 日本生態学会第62回全国大会, Mar. 2015, Japanese, 鹿児島県鹿児島市, Domestic conference環境DNA分析を用いた希少在来種と近縁外来種の流域スケール調査：京都府桂川のオオサンショウウオを例にOral presentation
- 日本生態学会第62回全国大会, Mar. 2015, Japanese, 鹿児島県鹿児島市, Domestic conference環境DNAとマルチプレックスPCRを用いた複数魚種の同時検出Poster presentation
- 第62回日本生態学会大会, Mar. 2015, Japanese, 鹿児島大, Domestic conferenceトノサマガエルの減少メカニズムの解明～土地利用形態による餌資源変化の検討～Poster presentation
- Joint 2014 Annual Meeting British Ecological Society and Société Française d’Ecologie, Dec. 2014, English, Lille, France, International conferenceA basin-scale application of environmental DNA assessment for rare endemic and exotic giant salamander species in JapanPoster presentation
- 第61回日本生態学会大会, Mar. 2014, Japanese, 広島, Domestic conference立山高山帯における訪花昆虫体表付着花粉と柱頭付着花粉の関係Poster presentation
- 第61回日本生態学会大会, Mar. 2014, Japanese, 広島, Domestic conference半自然草原における生物多様性の減少メカニズム－多群集での検証Poster presentation
- 第61回日本生態学会大会, Mar. 2014, Japanese, 広島, Domestic conference送粉者相の異なる島嶼間の送粉ネットワークの比較Poster presentation
- Frontiers in Amphibian Biology: Endangered Species Conservation and Genome Editing, Mar. 2014, English, Higashi-Hiroshima City, Japan, International conferenceLarge-scale environmental DNA assessment for Japanese and Chinese giant salamanders in Katsura River, JapanPoster presentation
- 日本陸水学会第78回大会, Sep. 2013, Japanese, 滋賀県大津市, Domestic conference環境DNAを用いた在来および外来オオサンショウウオの検出Oral presentation
- INTECOL, Aug. 2013, English, London, International conferenceSpatial and temporal beta-diversity of herbivorous insects declines due to land-use changes in agricultural semi-natural grasslands in Japan.Poster presentation
- The 97th Annual Meeting of Ecological Society of America, 7 Auguest 2012, Portland., Aug. 2012, English, International conferenceDoes Intermediate Disturbance Hypothesis explain mechanisms of biodiversity decline in agricultural lands? Perennial plants play key roles in maintaining herbivorous insect diversity.Poster presentation
- The 59th Annual Meeting of Ecological Society of Japan & The 5th EAFES international Congress, 18 March 2012, Mar. 2012, English, Otsu, Ryokoku University., International conferenceThe relationship between the Pollen/Ovule ratio and functional group diversity of pollinators in flowering plants.Poster presentation
- The 59th Annual Meeting of Ecological Society of Japan & The 5th EAFES international Congress, 18 March 2012, Mar. 2012, English, Otsu, Ryokoku University., International conferenceMechanism of decrease in herbivorous insects diversity in semi-natural grassland - Effects of changes in plant community –.Poster presentation
- The 59th Annual Meeting of Ecological Society of Japan & The 5th EAFES international Congress, 18 March 2012, Mar. 2012, English, Otsu, Ryokoku University., International conferenceEffects of urbanization on genetic structures in two paddy-associated frog species with different dispersal habits.Poster presentation
- The 59th Annual Meeting of Ecological Society of Japan & The 5th EAFES international Congress, 18 March 2012, Mar. 2012, English, Otsu, Ryokoku University., International conferenceDecrease in plant diversity due to changes in management measures and land abandonment in meadows.Poster presentation
- 第59回日本生態学会大会, 2012, Japanese, Domestic conference絶滅危惧種ハリママムシグサの保全遺伝学Poster presentation
- 第55回 日本生態学会福岡大会, Mar. 2008, Japanese, 福岡国際会議場, Domestic conference里草地草本の宝庫“棚田”の魅力 〜宝塚市におけるワレモコウの生育分布から〜Poster presentation
- 第55回 日本生態学会福岡大会, Mar. 2008, Japanese, 福岡国際会議場, Domestic conference里草地における多様性ホットスポットー稀少植物はどこにいるのか？ーPoster presentation
- 第55回 日本生態学会福岡大会, Mar. 2008, Japanese, 福岡国際会議場, Domestic conference草原性植物はため池が支えている？ 〜Vincetoxicum属2種の生育分布から〜Poster presentation
- 第55回 日本生態学会福岡大会, Mar. 2008, Japanese, 福岡国際会議場, Domestic conference深泥池における訪花昆虫群集の変遷Poster presentation
- 第55回 日本生態学会福岡大会, Mar. 2008, Japanese, 福岡国際会議場, Domestic conferenceネジバナはなぜ捩れているか−花序構造と他家受粉促進戦略−Poster presentation
- 第55回 日本生態学会福岡大会, Mar. 2008, Japanese, 福岡国際会議場, Domestic conferenceアザミ２種が明かす、里草地管理の重要性Poster presentation
- 第55回 日本生態学会福岡大会, Mar. 2008, Japanese, 福岡国際会議場, Domestic conference1+1>2?河川の合流点で種多様性が増加するPoster presentation
- Kansai Organization for Nature Conservation2009 - Present
- Botanical Society of America2005 - Present
- Ecological Society of Japan1993 - Present
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), Kobe University, 01 Apr. 2024 - 31 Mar. 2028Evaluation of conservation value of semi-natural grasslands based on plant diversity and endemism: a comparison with natural grasslands
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), Kobe University, 01 Apr. 2023 - 31 Mar. 2027Disparities and effects of acknowledgement of ecosystem services in daily life: developing a method for improving urban regional environment and health
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), Kobe University, 01 Apr. 2022 - 31 Mar. 2026Valuation and conservation of urban ecosystem services under changing population structure
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Grant-in-Aid for Scientific Research (C), Hiroshima University, 01 Apr. 2020 - 31 Mar. 2023Multi-site comparsion in communities and functions of pollinator insects toward conservation of wetland ecosystems本申請課題では、島根県・広島県に点在する湿地群に生育する多様な植物種を対象に、その送粉昆虫群集の網羅的な解明および周辺環境の違いによる送粉昆虫群集や送粉成功度の違いを明らかにすることを目的とするものである。2021年度は、広島県北広島町の八幡湿原に点在する大小約30の湿地群を対象として、開花植物の種同定と開花量、および各植物の訪花昆虫のサンプリングを行った。調査は春・夏・秋の3回行い、全部で1000個体以上の訪花昆虫（主に双翅目と膜翅目）を捕獲した。また、送粉成功度の指標の一つとして柱頭付着花粉数を計測するため、一部の植物種について開花後の柱頭を採集した。今後、湿地のサイズ（ドローンで計測）や湿地内の環境（開空度、開花量）、周辺環境（自然林、人工林、水田など）と訪花昆虫の群集構造との関係や、訪花昆虫の群集構造と送粉成功度との関係について、解析を行う予定である。 また、昨年度島根県赤名湿地においてインターバル撮影カメラを用いて湿地性植物38種の訪花昆虫調査を行った。今年度はこの調査により得られた約6.5万枚の写真を分析し、同じ植物を捕獲調査により調査した場合と比較して、調査方法としての有効性を検証した。その結果、インターバル撮影カメラを使った調査でも各植物の送粉昆虫群集は捕獲調査の結果とほぼ変わらず、植物―送粉昆虫のネットワークを群集レベルで把握する際にインターバル撮影カメラは有用なツールであることが分かった。 これらの成果は第69回日本生態学会などで発表した。また、現在投稿論文を準備中である。
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Grant-in-Aid for Scientific Research (B), Kobe University, Apr. 2019 - Mar. 2023, Principal investigatorAdaptive significance of morphologically complex flowers in natural grassland communities今年度は、再現可能な測定方法による客観性の高い花の複雑性指標の開発を目指して、花の撮影画像を用いた花および花被片の形質測定を行なった。調査は菅平高原ダボススキー場において生育する90種を超える被子植物の花を対象として、正面および側面2方向（直交する3軸方向）から、花とともにスケールを入れた写真をデジタルカメラを用いて撮影した。さらに、撮影に用いた花から送粉者の誘引に関連する花被片を分離し、平面状に展開し、スケールとともにデジタルスキャナで読み、デジタル画像とした。これらの画像を解析ソフトimageJを用いて解析し、各軸方向から見える花の縦横長や面積、全ての花被片の平面面積を算出した。ここで算出した計測値を組み合わせて、複数の花形態に関する指標作成を行なった。また、作成した指標と送粉者相との関係も解析し、指標の有効性を抽出する作業を行なった。その結果、花の立体性指標（正面と側面の比）や花被片の複雑性指標（花として見えている面積と花被片の平面面積の比）は送粉者相（マルハナバチ優占か、ハエ目優占か）を説明できた。一方で、定性的な左右相称性区分（左右相称花/放射相称花）も送粉者相と関係がみられたが、画像データを使った左右相称性指標（正面写真における縦長と横長の比等）は送粉者相との関係が見られなかった。以上のように、今回は花被片の画像データを元にした指標作りを行なったが、一定の成果がみられた。 また三浦半島黒崎の鼻における海岸草原で、年５回、群集の開花種および送粉者の調査を行なった。また同時に虫媒種の花色の調査も行った。データは現在まとめているところである。
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Grant-in-Aid for Scientific Research (C), Okayama University, Apr. 2019 - Mar. 2022, CoinvestigatorAdaptive significance and mechanism of environment-dependent sex determination in flowers本研究では、雄性両全性同株ケツユクサ（Commelina communis f. ciliata: ツユクサの一品種）を材料に、日長、土壌栄養環境、B1（花序の中で最初に咲く花）両性花の結実の有無がB2花（花序の中で2番目に咲く花）の性表現型に影響するメカニズムを総合的に明らかにすることを目的とした。 本年度は「生育環境の日長が異なる地域個体群（エコタイプ）は、B1両性花の結実後であってもB2花に両性花が誘導されるのに必要な暗期の長さが異なるよう適応しているか」「気温上昇によって秋の生育期が延長された場合、短日条件が花の両性化をもたらすことによって種子生産量が増加する可能性があるか 」という問いに答えるため、岩手県盛岡市、長野県上田市、兵庫県神戸市、愛媛県松山市より植物体および種子の採取を行った。採取した植物は岡山大学内施設および国立環境研究所内施設にて育成後に種子を採取し、保存した。保存した種子は低温湿層処理を行ったのちに25度で発芽・育成させ、以下の実験に用いた。 採取した系統を用いて、日長条件を変えて育成し、花成およびB2花に両性花が誘導される際の連続した暗期の長さについて、人工気象器を用いてエコタイプ毎に評価した。実験は現在継続中である。また、ケツユクサにはエコタイプ毎に染色体数が異なることが報告されているため、染色体数の確認を行った。その結果、兵庫県神戸市より採取した個体と長野県上田市より採取した個体は同様に2n=46であった。
- 公財）市村清新技術開発財団, 植物研究助成金, Mar. 2017 - Apr. 2020, Principal investigator伊豆諸島における長口吻送粉者の不在が植物の繁殖に与える影響
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Grant-in-Aid for Scientific Research (C), Okayama University, 01 Apr. 2016 - 31 Mar. 2020It has been suggested that internal resources are involved in the mechanism of plastic sexual expression determination of individual flowers in plants, but the details are unknown. In this study, we tested whether locally occurring resource limitations within individuals could explain the sex determination of individual flowers. Using Commelina communis f. ciliata, which has hermaphroditic and male flowers in a single plant, we examined the existence of fruiting of first flower (B1) in the inflorescence, and sex expression and resources of next blooming flower (B2). We also performed a comparative transcriptome analysis of male and female flowers. As a result, the decrease of resources in the inflorescence was not remarkable, and the nitrogen and phosphorus concentration in the bud of B2 did not differ by the existence of B1 fruiting. These results suggest that the resource limitation in the inflorescence is not a factor that directly controls the sex of B2.
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Grant-in-Aid for Scientific Research (C), University of Tsukuba, Apr. 2017 - Mar. 2020We studied (1) plants, (2) butterflies, (3)coleopteran, (4)soil in three different vegetation types, (i) old grasslands generated > 70 years ago, (ii) newer grasslands and (iii) forests, in and near ski runs in Sugadaira, Kirigamine and Hakuba in the central Japan. We found (1) plant species richness was higher in old grasslands and plant communities in new grasslands has similarities to that of forests, (2) large old grasslands had specific butterfly communities, (3) many of formerly-believed forest coleopterans were distributed in grasslands, and (4) in the change process from grasslands to any of Pinus, Betura or Larix forests, blackness of andsol decreased only 10 - 40 years since forestation began.
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Grant-in-Aid for Scientific Research (B), Kobe University, Apr. 2016 - Mar. 2019, Principal investigatorThe study examined the impacts of urbanization on semi-natural grassland plant and herbivore diversity and interactions within paddy ecosystems around a megacity area, the Osaka-Kobe metropolitan area, one of the Monsoon Asian megacities. We found that both plant and herbivore diversity decreased by habitat loss, fragmentation, split and degradation owing to urbanization in this area. Changes in soil pH facilitated the establishment of native and exotic annual plants in urbanized semi-natural grasslands. Habitat fragmentation, split, and degradation have decreased perennial species richness, leading to loss of some butterflies and orthopterans. Plant-pollinator networks of more urbanized grasslands had lower plant and pollinator richness and were more generalized than those of rural grasslands. Thus, urbanization has decreased biodiversity and the ecosystem functions in very species-rich paddy ecosystems in the Monsoon Asian region.Competitive research funding
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), University of Toyama, 01 Apr. 2015 - 31 Mar. 2018Ecological function of dipteran pollinators in plant community: from the perspective of pollinators behavior and pollen flow.To investigate the ecological significance of dipteran pollinators at a community scale, we compared plant-pollinator communities where the proportion of dipteran pollinators differs. In general, diversity of flower colors, as well as the diversity of flower morphology, appeared to decrease as the rate of dipteran pollinators in pollinator community increase. Differences in the composition of flower color and morphology between communities are due to differences in the pollinator fauna in these communities. We also found that color preference of dipterans differed between species. Our survey further revealed that rate of conspecific pollen grains to the total pollen grains on the stigma of the dipteran pollinated plants was large as much as those of the hymenopteran pollinated plants. Our results suggest that dipteran pollinators play a significant role in maintenance of plant community.
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research, Grant-in-Aid for Challenging Exploratory Research, Kobe University, 01 Apr. 2015 - 31 Mar. 2018This research investigated ecosystem valuation around Mt. Rokko, which is located near Kobe, a major city in Japan. Special attention was paid to how differences in lifestyle and experiences of valuators influence willingness to pay. It was found that certain experiences had a significant effect on valuation of ecosystem services. From psychological analysis, it was also found that psychological measure offered the different results from welfare measure. These findings suggest the importance of considering the diversity of valuators, and it also warns the extinction of experience with nature under on going urbanization for urban ecosystem conservation. This research concludes that measurement approach, recognition process, urbanization and lifestyle change are important in ecosystem service valuation.Competitive research funding
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Young Scientists (B), University of Toyama, 28 Apr. 2011 - 31 Mar. 2015A network analysis of plant-pollinator interactions in alpine ecosystems in japan.We analyzed the pollination network structure of alpine ecosystem in Tateyama Mountains, central Japan. The pollination community was significantly nested and modular. However, significant nestedness resulted mainly from the bias of species abundance. In the modular matrix model, on the other hand, there existed many links outside the modules. We then categorized plants and flower visitors into several groups in accord with quantitative data of the flower visitation pattern, assumed the groups as units, and constructed model in which a single pollination group may use one to a few plant groups. In the new model, number of exceptional links was small, which implies that the model could adequately mentioned the structure of pollination network.
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Grant-in-Aid for Scientific Research (C), Kobe University, 28 Apr. 2011 - 31 Mar. 2015, Principal investigatorDeclines in plants and herbivorous insects due to land-use abandonment and intensification, have been studied in agricultural areas worldwide. We compared plant richness and butterfly and orthopteran richness and diversity among three land-use types in semi-natural grasslands: abandoned, traditional and intensified terraces. Plant and herbivore richness and diversity were significantly lower in abandoned and intensified grasslands than in traditional grasslands. Changes in the mowing frequency explained plant richness decline as a consequence of land abandonment and intensification. The results suggest that a mowing frequency of 2-3 times per year enhance herbivore richness directly, as well as indirectly by enhancing plant diversity.Competitive research funding
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B), Grant-in-Aid for Young Scientists (B), Kobe University, 2008 - 2010, Principal investigatorDistribution of more than 50 endangered species in semi-natural grasslands around paddy fields (ca. 1300ha) was investigated in order to find local biodiversity hotspots around agricultural landscapes. Our research group found that the upper areas of paddy terraces were local hotspots in which many endangered species coexisted together. Higher, steeper fields farther from roads in the upper areas of paddy terraces were more frequently abandoned in our study area. We also compared distribution pattern between three endangered and one common species and found endangered species had significantly more overlap with the distribution of fields at risk of abandonment than did the common species. In addition, the endangered species were significantly less widely distributed in consolidated fields.Competitive research funding
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B), Grant-in-Aid for Young Scientists (B), Kobe University, 2005 - 2007花方位・花角度による送粉者の行動制御メカニズムこれまでの斜面地における適応的な花方位の研究の発展として、平地環境において花序を持つ植物が個々の花をどのように向ける事が適応的研究を行った。具体的には花を一方方向のみに向けた人工花序とそれぞれの花が60°ずつずれた方向に向れ360°へ向けた人工花序とで、訪花者(クロマルハナバチ)の訪花行動への影響を調べた。また実際に、螺旋状花序(捩れ方に個体へにが存在する)をつけるネジバナを対象に、花序の花の配置がどのように送粉成功へ影響を与えているのか調査を行った。結果、平地環境では一方向花序では、その方向に対するアトラクション効果が高くなるが、多方向へのアトラクションが減少するため、多方向花序にくらべ訪花頻度が減少することが明らかになった。ネジナバを用いた野外調査からは、やはり花を一方向へ向けた花序では、花粉の持ち出しが減少した。また、花間の角度が大きくなりすぎた花序でも花粉の持ち出しが減少している事を発見した。ここから花を様々な角度に向けると花が複数まとまることによるディスプレイサイズ増加の効果を打ち消してしまう事も明らかになった。 以上の研究結果は、花序における個々の花の配置は、アトラクションの影響する範囲やディスプレイサイズ、その結果、繁殖成功に大きく影響をあたえる形質である事が明らかになった。このことは、これまでの花序によるアトラクション効果の研究に新しい視点を加える事のできる結果である。
- 笹川科学研究助成金, Apr. 2005 - Mar. 2006, Principal investigator水田生態系における人為的水管理による植物・送粉者の多様性創出メカニズムの解明とその保全方策
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for JSPS Fellows, Grant-in-Aid for JSPS Fellows, Kyoto University, 2000 - 2001植物、送粉者群集の多様性の研究