| 要旨トップ | 目次 | | 日本生態学会第73回全国大会 (2026年3月、京都) 講演要旨 ESJ73 Abstract

一般講演（口頭発表） J02-07 （Oral presentation）

#### Scale- and taxa-dependent response of soil bacterial communities to environmental factors across Chinese natural forests【E】

*Linzi JIANG（IAP, CAS）, Binghao JIA（IAP, CAS）, Kazuo ISOBE（Peking University）

As key components for sustaining terrestrial ecosystem functions, soil bacterial communities make it vital to clarify their variation patterns and driving mechanisms at regional and continental scales. Here, 16S rRNA gene sequencing was selected to analyze soil bacterial communities in 162 Chinese natural forest plots across different eco-geographical divisions. At the regional/continent scale, variations in bacterial community spatial patterns were revealed by analyzing the shaping of community composition by environmental heterogeneity. From the taxonomic perspective, niche differentiation of dominant phyla driven by environmental changes was also explored. Results showed that distinct climatic zones and arid-humid regions select for unique genera. At the regional scale, solar radiation (RAD) and above-ground biomass (AGB) were the primary drivers of community composition in the cold temperate zone; pH, soil organic carbon (SOC), and total phosphorus (TP) acted as regulatory factors in the temperate zone; while mean annual air temperature (MAT) and mean annual ground temperature (MAGT) emerged as dominant drivers in the subtropical zone; MAT, MAGT, sand content, soil water content (SWC), and AGB collectively shaped the composition in humid regions, whereas RAD was the main driver in arid/semi-arid regions. At the continental scale, pH primarily affects the community composition along the north-south gradient, while SWC and AGB drove that along the west-east gradient. Moreover, dominant bacterial phyla respond to environmental factors in complex ways at the regional scale; but environmental filtering shapes their continental distribution, which may in turn affect the spatial distribution of entire bacterial communities continentally. Overall, our study clarifies the scale-dependent and taxa-dependent responses of soil bacterial communities in Chinese natural forests to environmental factors, which not only establishes a foundation for predicting the evolutionary trends of forest soil microecosystems under future climate change but also provides references for formulating adaptive forest management plans based on ecological process mechanisms.

日本生態学会