气候变暖会直接影响物种的生长发育过程，进而影响群落乃至生态系统结构和功能。雌雄异株植物在植物界中约占6％左右，是陆地生态系统的重要组成部分。青杨是我国广泛分布的雌雄异株植物，对维持生态系统稳定性和森林恢复具有重要意义。先前关于雌雄异株植物的研究主要集中在其对非生物环境胁迫后的响应与适应，而对该类植物在气候变暖下对生物因子的响应的研究依然较少。本项目拟以青杨为模式材料，比较增温下青杨雌雄植株对其植食性昆虫的防御响应差异，其目的是(1)揭示气候变暖下雌雄青杨对植食性昆虫的物理和化学防御响应差异，(2)探讨气候变暖背景下雌雄植株对昆虫的防御机制与生长的关系，为杨树人工林培育和构建提供建议。这些研究结果为气候变暖下探讨植物在性别水平上的防御机制及植物生长、繁殖与防御机制的关系提供理论依据，也为未来气候变暖下杨树种群维持乃至杨树人工林生态系统的构建提供参考。

The growth and development processes of plant can be modified by climate warming, and result in the change of structure and function of plant community, even of ecosystem. Dioecy is reported about 6% of angiosperm species, and it is an essential group that can not be ignored in terrestrial ecosystem. Populus cathayana Rehd. is a widely distributed dioecious tree species in China and plays important roles in maintaining ecological stability and forest restoration. Previous studies focus on the ecophysiological responses of dioecious plant to abiotic stress, however, few study has been putted on the defense responses to biotic stress under global warming. In this project, to investigate the defense responses of dioecious plant to insect herbivore under elevated temperature, P. cathayana has been chosen as a model plant, for evaluating under warming (1) sexual differences in defense to insect herbivore in P. cathayana; (2) the relationship between defense and growth of P. cathayana females and males. The results reported here can provide models on sexual anti-insect defense of dioecious species and plant how to integrate among growth, reproduction and defenses under warming, and also can contribute to understand population maintenance and forest ecosystem of Populus plantation construction under future climate warming.