虽然有关亚热带森林树种沿环境梯度分布格局的研究越来越多，但对其水热驱动机制的认识甚少。本项目选择浙江东部海陆交错区这一降雨格局变化剧烈的环境梯度，以已建成的98个森林固定样地和2个长期大型森林动态样地为依托，统计分析群落物种组成随陆海降雨梯度的替代特征，揭示优势种多度在降雨梯度，以及大型群落动态样地内湿润与干旱地形的分异格局。测量各群落优势种碳氮水吸收、运输和利用功能性状，探索树种水分耐受权衡策略调适的水分ß生态位沿降水梯度的分离格局。开展控制实验，评价不同树种的干旱敏感性。分析树种干旱敏感性和水分耐受权衡策略性状与其多度的数量关系，阐明森林树种分布对海陆交错区降雨梯度的功能响应格局。本研究旨在从生理机能层次揭示海陆过渡区树种分布随水分梯度更替的生态机制，从而推进物种分布与其水热机能变化因果联系研究，也为预测未来降雨格局改变情况下物种分布区的潜在位移范围提供理论基础。

Although patterns of tree species distributions along environmental gradients have been amply documented in subtropical forests, mechanisms causing these patterns are seldom known, especially with respect to the species reaction to water and temperature. In this project, spatial replace patterns of species composition, particularly the abundance distribution of dominant tree species will be quantified by relying on the forest inventory data across 98 permanent forest plots and 2 large forest dynamics plots along a rainfall gradient that is shaped by sea-land-interaction in eastern Zhejiang Province, China. Spatial variation in ecological trade-offs of water tolerant strategies and ensuing hydrological ß niche segregation across tree species will be revealed along this rainfall gradient, through measuring functional traits associated with tree’s water physiology, hydraulic architecture, and whole-plant economic spectrum in dominant tree species. In addition, drought sensitivity will be assessed by using a drought-control experiment. Finally, in order to determine whether differences in functional strategies of dominant tree species can interpret their abundance distribution over regional (i.e., rainfall gradient) and local (i.e., between locations that soil water availability is mediated by topography in the large forest dynamics plot) scales, drought sensitivity and functional traits of water tolerance will be correlated respectively, with each of species abundance and density in natural condition. The objective of this project is to explore the ecological mechanism of species distribution patterns with regard to their abundance replacement along a rainfall gradient in the sea-land transition zone. The findings of this research will improve our understanding of the causal relationship between the species distribution patterns and the associated variation in functional reaction of species to water and temperature. Additionally, the results in this study will provide theoretical basis for predicting potential shift ranges in tree species distribution when rainfall pattern changes in future.