演替和气候对我国纬度梯度上森林的个体和群落尺度相关生长的影响机制

相关生长规律既是当前理论研究的热点，又对全球变化下的森林碳汇估算、群落动态预测有重要的现实意义。但目前研究还存在一些问题，如：1)对随演替和气候变化的生态过程对相关生长的影响机理，研究亟待深入，2)群落尺度相关生长机理的研究相对不足，3)观测研究和理论模型研究尚未统一。我们在长期研究的基础上，选择我国森林区寒温带直至热带的地带性森林及其完整的演替序列，系统研究个体和群落水平相关生长的大尺度格局。重点探讨：1)气候、局域环境、进化、发育阶段、群落生态过程(竞争、更新等)，如何直接或间接起作用、共同影响个体和群落尺度的相关生长？2)相关生长关系偏离生态学代谢理论预测的规律，以及上述5类因素哪些是导致偏离理论值的主导机制？项目的研究不仅有助于阐明干扰和气候对不同尺度相关生长的影响机理，还可望为改进现有理论找到关键方向，以更好地为我国森林(以次生林、人工林为主)的经营、恢复和应对全球变化服务。

Allometric relationships of plant individuals and communities are not only theoretical focus of ecology, but also are important tools for estimating forest dynamics and carbon sink under global change. However, there are still some critical (major) questions on allometric relationships remained unresolved: 1) the mechanisms of how forest succession influence allometries have not been well understood; 2) the abiotic and biotic modulators of allometries at community scale are much less examined compared with that at individual scale; 3) empirical studies are largely conducted independent of existing theoretical models. This study is designed to examine some allometric relationships at individual and community scales, across both the latitudinal and successional gradients of Chinese forests, to explore questions as follows. 1) How do various abiotic and biotic factors affect allometries at individual and community scales, directly and indirectly? The potential modulators examined including: climate gradient (energy and water availability, and winter coldness), phylogeny, development stage of individuals and communities, local environmental factors, and ecological processes in forest communities (e.g. competition and regeneration). 2) When and how do observed allometric exponents deviate from predictions of Metabolic scaling theory (MST)? Which of the above-mentioned abiotic and biotic factors are the major drivers of deviations from theory predictions? Answering these questions is not only critical for understanding the mechanisms underlying geographic patterns of scaling relationships, but also important for improving the existing allometric models so that they can predict patterns beyond primary forests. Chinese Forests in China are mainly composed of secondary forests and plantations, and thus improved understandings of allometric laws are especially important for the restoration and management of our forests in response to global change.