研究者データベース
小林 勇太KOBAYASHI Yutaｺﾊﾞﾔｼ ﾕｳﾀ
| ■所属部署名 | 農学部附属広域都市圏フィールドサイエンス教育研究センター | |||
| ■職名 | 助教 | |||
Last Updated :2026/07/29
業績情報
氏名・連絡先
氏名
ｺﾊﾞﾔｼ ﾕｳﾀ, 小林 勇太, KOBAYASHI Yuta
主たる所属・職名
農学部附属広域都市圏フィールドサイエンス教育研究センター, 助教
学位
教育・研究活動状況
担当授業科目
科学研究費助成事業
- 基盤研究（B）
水質改善により河川の水生生物は回復するか？：回復ポテンシャルと影響物質群の評価
自 2024年, 至 2024年 - 国際共同研究加速基金（国際共同研究強化（B））
森林動態モデルによる生物多様性と気候変動の両者課題の同時解決策
自 2024年, 至 2024年 - 若手研究
老木はいつ死ぬのか、どう死ぬのか
自 2024年, 至 2026年 - 国際共同研究加速基金（国際共同研究強化（B））
森林動態モデルによる生物多様性と気候変動の両者課題の同時解決策
自 2023年, 至 2023年 - 国際共同研究加速基金（国際共同研究強化(B)）
森林動態モデルによる生物多様性と気候変動の両者課題の同時解決策
自 2022年, 至 2022年 - 基盤研究（B）
水質改善により河川の水生生物は回復するか？：回復ポテンシャルと影響物質群の評価
自 2025年, 至 2025年 - 国際共同研究加速基金（国際共同研究強化（B））
森林動態モデルによる生物多様性と気候変動の両者課題の同時解決策
自 2025年, 至 2025年
論文
- Predicting macroinvertebrate average score per taxon (ASPT) at water quality monitoring sites in Japanese rivers
Environmental Science and Pollution Research
Springer Nature
2024年04月, 研究論文（学術雑誌）, 共同, 31, DOI(公開)(r-map), 28538, 28548 - Microtopography and vegetation generate uneven predation pressure on forest insects
Nakatsuji, Kohei; Kobayashi, Yuta; Yoshida, Tomohiro
ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY
ELSEVIER
Predation plays an important role in the coexistence of multiple species within forest ecosystems. It is spatially heterogeneous and influenced by the surrounding environment at different spatial scales. Studies focusing on multiple environmental factors in systems with high spatial complexity are lacking, but elucidating the effects of local environmental factors within a forest could assist in understanding the effects of local differences in predation pressures on multispecies coexistence. Here, we examined the effects of microtopography and vegetation on predation pressure using the model caterpillar method. We hypothesized that differences in microtopography and vegetation types would result in different predation pressures on invertebrates within a forest. Insect attacks were dominant throughout the study period. The attack rates on the model caterpillars were also lower on hill tops and evergreen deciduous trees. Predation pressure within the forest was heterogeneous and independently influenced by topography and vegetation type. Our results suggest that environmental heterogeneity within forests may lead to highly variable predation pressures and affect multispecies coexistence. This study suggests that microtopography and vegetation types within forests should be considered for biological control.
2024年12月, 研究論文（学術雑誌）, 共同, 125, 1146-609X, DOI(公開)(r-map) - Ant utilization of tree trunks in relation to environmental factors in a temperate forest
Inoue, Kanata Sakaya; Nakatsuji, Kohei; Koyama, Satoshi; Kobayashi, Yuta; Yoshida, Tomohiro
ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY
ELSEVIER
Forests exhibit complex three-dimensional structures, wherein abiotic factors vary both vertically and horizontally. The interaction between organisms and these factors drives the remarkable biodiversity within forests. Tree trunks serve as vital conduits for organisms moving vertically within the forest, facilitating biodiversity maintenance. Organisms moving vertically through tree trunks in forests face varying abiotic conditions, which may enhance their resilience to long-term environmental changes. Despite numerous studies comparing canopy and ground communities, the distribution of organisms across multiple strata remains poorly understood. Here, we explore the correlation between the horizontal distribution of ants in a forest and environmental factors (topography, tree size, tree species), with a specific focus on their presence on tree trunks. Visual observations were conducted to document ant species richness on tree trunks, supplemented by pitfall traps to quantify soil arthropod biomass, serving as an indicator of protein availability. The results revealed that ant species richness on tree trunks varied based on topography and tree species, showing a positive correlation with tree size. However, no significant relationship emerged between soil arthropod biomass and ant richness on tree trunks. Furthermore, no discernible trend suggesting that certain species were less likely to co-occur was observed; instead, a tendency for some species to co-occur was found. These findings highlight the horizontal heterogeneity in the distribution of ants with respect to topography, tree species, and tree size within the forest.
2024年12月, 研究論文（学術雑誌）, 共同, 125, 1146-609X, DOI(公開)(r-map) - Effects of artificial night lighting on a web-building spider species in urban green spaces
Fuse, Shun; Yoshida, Tomohiro; Kobayashi, Yuta
ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY
ELSEVIER
Urban green spaces are biological habitats that play an important role in maintaining urban biodiversity and are affected by artificial light at night (ALAN). Determining the effects of ALAN on predators in urban green spaces is important for promoting the maintenance and conservation of these functions of insect communities in urban green spaces. We investigated the effects of ALAN on a web-building spider species (Trichonephila clavata) in urban green spaces in the Tokyo metropolitan area, Japan. We used a GPS receiver to determine the positions of streetlights and spider webs and classified the webs into two groups: those within the reach of streetlights and those outside their range. We then measured the web distribution (web density), web size, female traits (femur length and body weight), and male presence. Web densities in the light conditions were higher and web sizes smaller than those of webs in the no light conditions. Female body weight and length were also significantly lower in the light conditions than in the no light conditions. However, female body condition and male abundance did not differ between the light and no light conditions. Our results showed that T. clavata maintains some degree of fitness in urban fragmented green spaces although their physical characteristics and behaviour are altered by ALAN. Therefore, we suggest that measures to improve the quality within green infrastructure are required to maintain the function of generalist predators such as web-building spiders in urban green spaces.
2024年08月, 研究論文（学術雑誌）, 共同, 124, 1146-609X, DOI(公開)(r-map) - Parameters of 150 temperate and boreal tree species and provenances for an individual-based forest landscape and disturbance model
Thom, Dominik; Rammer, Werner; Albrich, Katharina; Braziunas, Kristin H.; Dobor, Laura; Dollinger, Christina; Hansen, Winslow D.; Harvey, Brian J.; Hlasny, Tomas; Hoecker, Tyler J.; Honkaniemi, Juha; Keeton, William S.; Kobayashi, Yuta; Kruszka, Sofia Saenz; Mori, Akira; Morris, Jenna E.; Peters-Collaer, Stephen; Ratajczak, Zak; Simensen, Trond; Storms, Ilie; Suzuki, Kureha F.; Taylor, Anthony R.; Turner, Monica G.; Willis, Susan; Seidl, Rupert
DATA IN BRIEF
ELSEVIER
2024年08月, 研究論文（学術雑誌）, 共同, 55, 2352-3409, DOI(公開)(r-map) - Beyond resilience: Responses to changing climate and disturbance regimes in temperate forest landscapes across the Northern Hemisphere
Dollinger, Christina; Rammer, Werner; Suzuki, Kureha F.; Braziunas, Kristin H.; Keller, Timon T.; Kobayashi, Yuta; Mohr, Johannes; Mori, Akira S.; Turner, Monica G.; Seidl, Rupert
GLOBAL CHANGE BIOLOGY
WILEY
Climate change has profound impacts on forest ecosystem dynamics and could lead to the emergence of novel ecosystems via changes in species composition, forest structure, and potentially a complete loss of tree cover. Disturbances fundamentally shape those dynamics: the prevailing disturbance regime of a region determines the inherent variability of a system, and its climate-mediated change could accelerate forest transformation. We used the individual-based forest landscape and disturbance model iLand to investigate the resilience of three protected temperate forest landscapes on three continents-selected to represent a gradient from low to high disturbance activity-to changing climate and disturbance regimes. In scenarios of sustained strong global warming, natural disturbances increased across all landscapes regardless of projected changes in precipitation (up to a sevenfold increase in disturbance rate over the 180-year simulation period). Forests in landscapes with historically high disturbance activity had a higher chance of remaining resilient in the future, retaining their structure and composition within the range of variability inherent to the system. However, the risk of regime shift and forest loss was also highest in these systems, suggesting forests may be vulnerable to abrupt change beyond a threshold of increasing disturbance activity. Resilience generally decreased with increasing severity of climate change. Novelty in tree species composition was more common than novelty in forest structure, especially under dry climate scenarios. Forests close to the upper tree line experienced high novelty in structure across all three study systems. Our results highlight common patterns and processes of forest change, while also underlining the diverse and context-specific responses of temperate forest landscapes to climate change. Understanding past and future disturbance regimes can anticipate the magnitude and direction of forest change. Yet, even across a broad gradient of disturbance activity, we conclude that climate change mitigation is the most effective means of maintaining forest resilience.
2024年08月, 研究論文（学術雑誌）, 共同, 30, 8, 1354-1013, DOI(公開)(r-map) - Plant-mycorrhizal associations may explain the latitudinal gradient of plant community assembly
Shinohara, Naoto; Kobayashi, Yuta; Nishizawa, Keita; Kadowaki, Kohmei; Yamawo, Akira
OIKOS
WILEY
Biogeographical variation in community assembly processes forms the basis of the latitudinal gradient of biodiversity by driving beta-diversity. Classical studies on community assembly predict environmental filtering affecting beta-diversity more strongly at higher latitudes, where productivity is lower and abiotic stress is stronger. Contrary to this prediction, recent evidence indicates that plant community composition at higher latitudes exhibits more spatially clustered distributions independently of background environments, suggesting the importance of spatial processes, such as priority effects. In this study, we propose a hypothesis that resolves this paradox by considering plant-soil feedback and biogeographic variations in the dominant mycorrhizal type: we predict that the increasing prevalence of ectomycorrhizal (EcM) trees with latitude contributes to the spatially clustered distribution of plants, as EcM trees tend to exhibit positive plant-soil feedback. We analyzed a large-scale standardized dataset of Japanese forests covering a latitudinal gradient of >10 degrees and found that 1) the proportion of EcM trees was higher at higher latitudes, and 2) EcM tree-rich communities exhibited more spatially clustered distributions likely due to positive plant-soil feedback. Consequently, 3) tree species composition at higher latitudes was better explained by spatial variables suggesting the importance of priority effects. Consistent with the predictions of the plant-soil feedback theory, these patterns were more pronounced in understory than in canopy communities. Taken together, our results lend support to our hypothesis that biogeographic variation in tree community assembly patterns is defined by mycorrhizal types and plant-soil feedback, thereby resolving a paradox in the latitudinal gradient of plant community assembly. Our work highlights that plant mycorrhizal type underlies the determinants of beta-diversity which is a critical component of the latitudinal gradient of diversity.
2024年06月, 研究論文（学術雑誌）, 共同, 2024, 6, 0030-1299, DOI(公開)(r-map) - Long-term Consequences on Soil Fungal Community Structure: Monoculture Planting and Natural Regeneration
Naka, Minagi; Masumoto, Shota; Nishizawa, Keita; Matsuoka, Shunsuke; Tatsumi, Shinichi; Kobayashi, Yuta; Suzuki, Kureha F.; Xu, Xinyu; Kawakami, Tomoya; Katayama, Noboru; Makoto, Kobayashi; Okada, Kei-ichi; Uchida, Masaki; Takagi, Kentaro; Mori, Akira S.
ENVIRONMENTAL MANAGEMENT
SPRINGER
Understanding the regeneration and succession of belowground communities, particularly in forests, is vital for maintaining ecosystem health. Despite its importance, there is limited knowledge regarding how fungal communities change over time during ecosystem development, especially under different forest restoration strategies. In this study, we focused on two restoration methods used in northern Japan: monoculture planting and natural regeneration. We examined the responses of the fungal community to monoculture plantations (active tree planting) and naturally regenerated (passive regeneration) forests over a 50-year chronosequence, using natural forests as a reference. Based on DNA metabarcoding, we assessed the richness of fungal Operational Taxonomic Units (OTUs) and their dissimilarity. Our findings revealed that soil fungal richness remained stable after natural regeneration but declined in monoculture plantations, from 354 to 247 OTUs. While the compositional dissimilarity of fungal assemblages between monoculture plantations and natural forests remained consistent regardless of the time since tree planting, it significantly decreased after natural regeneration, suggesting recovery to a state close to the reference level. Notably, the composition of key functional fungal groups-saprotrophic and ectomycorrhizal- has increasingly mirrored that of natural forests over time following passive natural regeneration. In summary, our study suggests that monoculture plantations may not be effective for long-term ecosystem function and service recovery because of their limited support for soil fungal diversity. These results underscore the importance of natural regeneration in forest restoration and management strategies.
2023年12月15日, 研究論文（学術雑誌）, 共同, 0364-152X, DOI(公開)(r-map) - Dominant temperate and subalpine Japanese trees have variable photosynthetic thermal optima according to site mean annual temperature
Kobayashi, Yuta; Haga, Chihiro; Shinohara, Naoto; Nishizawa, Keita; Mori, Akira S.
GLOBAL ECOLOGY AND BIOGEOGRAPHY
WILEY
Aim: Global flux data analyses have shown a significant positive and linear relationship between site-scale photosynthetic optimum temperature (Topt-s) and averaged temperature variables. However, as existing studies have not fully considered species composition, it remains unclear to what extent the change in Topt-s is derived from intraspecific plasticity or from a difference in species with a consistent species-specific Topt-s. We tested these two hypotheses using the satellite-derived enhanced vegetation index (EVI).Location: Subalpine and temperate forests in Japan.Time period: 2001-2020.Major taxa studied: Thirty-three tree species.Methods: Based on an in situ vegetation survey dataset, we identified 1814 EVI cells (250 m x 250 m) that were characteristic of the spectral reflectance of a single dominant species. For each cell, we pooled EVIs from 2001 to 2020 and estimated the temperature at the time of EVI peak as a species-specific Topt-s. We tested our hypotheses by fitting linear regression models to the Topt-s and mean annual temperature (MAT). A positive slope indicated support for the intraspecific plasticity hypothesis.Results: For 32 of the 33 tree species, the Topt-s increased with an increase in MAT. A linear mixed-effect model provided a good explanation of the variation in the Topt-s based on the MAT (intercept = 14.63, slope = 0.58, marginal R-2 = .78), with minimal effect of species difference (conditional R-2 = .75).Main conclusions: Our results support the intraspecific plasticity hypothesis. At least in East Asian subalpine and temperate forests, the Topt-s can be estimated from the MAT, irrespective of the dominant canopy species. The observed MAT-Topt-s relationship is consistent with the findings of previous photosynthetic studies and has important implications for the establishment of new algorithms for estimating gross primary productivity that can account explicitly for spatial and temporal differences in temperature-dependent photosynthetic responses.
2023年03月, 研究論文（学術雑誌）, 共同, 32, 3, 1466-822X, DOI(公開)(r-map), 397, 407 - 2023年01月, 研究論文（学術雑誌）, DOI(公開)(r-map)
- Misalignment between ecologically rapid and economically optimal forest restoration designs
Kobayashi, Yuta; Sato, Masayuki; Uchida, Kei; Mori, Akira S.
FOREST POLICY AND ECONOMICS
ELSEVIER
Because the benefits of forest restoration take a long time to materialize, it is desirable to design restoration projects with intergenerational equity in mind, particularly considering the perspectives and feelings of the generation bearing the costs. We conducted a contingent valuation survey with a payment card among the Japanese public focusing on forest restoration in Shiretoko National Park to estimate individual discount rates for carbon and biodiversity recovery. Specifically, we presented two forest restoration scenarios with varying recovery times and asked for their willingness to pay (WTP) for each. From these differences in WTP, the individual discount rates were estimated at 1.17 %. Using the estimated discount rates, cost-benefit analyses were performed on the simulation results of 31 different restoration scenarios with varying planting densities and number of species planted. We also performed the same analyses using commonly used discount rates of 4.0% and 6.0%. The results showed a divergence between the ecologically and economically optimal restoration scenarios, and that the economically optimal restoration scenario varied depending on the discount rate. This highlights the need for careful consensus building that combines ecological and economic perspectives in forest ecosystem management.
2025年03月, 研究論文（学術雑誌）, 共同, 172, 1389-9341, DOI(公開)(r-map) - Climatic differences among habitats shape the balance between maximum lifespan and life expectancy in Japanese tree species
Kobayashi, Yuta; Akasaka, Munemitsu
NATURE ECOLOGY & EVOLUTION
NATURE PORTFOLIO
Old trees, often living for hundreds or even thousands of years, play vital roles in maintaining biodiversity and ecosystem services. However, their extraordinary longevity occurs under rare circumstances, as most individuals succumb to mortality. From an optimal resource allocation perspective, species adopting a life-history strategy with a high potential maximum lifespan (PML) are expected to also have a higher life expectancy (LE). Here we developed a framework to assess the longevity of 1-cm-diameter trees and calculated the PML and LE for 53 major tree species in Japan. The results revealed that the PML (mean 378 years) was 4.7 times higher than the LE (mean 81 years). Both indices showed a positive correlation, with a regression slope of 0.34; however, the explanatory power of the model was low (R2 = 0.22). This can be attributed to the fact that LE exhibits a stronger negative response to climate-related habitat severity compared with that of PML. Our findings suggest two key points: (1) trees may adopt a hierarchical ordering of demographic parameters that prioritize long-term survival duration over average survival rate, and (2) considering this balance, which varies among species, could enhance the cost-effectiveness of ecosystem restoration.
2025年06月, 研究論文（学術雑誌）, 共同, 9, 6, 2397-334X, DOI(公開)(r-map)