中国东部森林常见树木生长的分布格局及其控制因素

Forest carbon sequestration is the most important component of the carbon cycling of the terrestrial ecosystems. Tree growth is the main input of the forest carbon sequestration. Tree growth is a result of the combined effects of life history strategy, ontogeny, local habitats and the species interaction in the community, with the influences of these factors varying across spatio-temporal scales. To better understand the mechanisms of forest carbon sequestration, it is necessary to explore distribution patterns and the underlying factors regulating these patterns of tree growths in different seasons. China is located in the monsoon region of the eastern Asia, and forest continuously distributed from south to north in its eastern parts, providing a unique opportunity to explore the large scale patterns of tree growths. In this project, we first precisely located the distribution of ca 15000 trees from 455 species of 32 zonal forests. We measured the growth of these trees every month using both hand-made dendrometer bands and automatic measurement data-loggers, we also measured the local climate and soil property of the plots and plant functional traits of the species. We aim to explore the patterns and seasonal characteristics of tree growth rate, and to disentangle the effects of species functional traits, tree size, neighboring trees and local habitats on tree growth rate of different seasons in eastern part of China. The results will help understanding the mechanisms of tree growth and provide scientific bases for the management of forests.

森林固碳是陆地生态系统碳循环的重要组分，树木生长是森林固碳的主要过程。树木生长是物种生活史策略、生长阶段、邻体作用、局域生境等因素综合作用的产物，不同因素对树木生长的影响会随时空尺度变化。研究森林树木生长的季节动态、分布格局及其控制因素，探讨不同因素对树木生长的影响及其区域分异，有利于促进理解森林固碳机制。中国东部地处季风区，具有连续分布的森林，为研究树木生长大尺度格局提供了独特的平台。本申请项目拟对我国东部32种地带性森林445种常见树种的近15000棵树木进行精确定位，采用生长环及茎干生长自动记录仪监测其生长速率的季节动态，并调查局域气候和土壤及植物的功能性状，以此研究树木生长速率与功能性状、初始胸径、邻体作用及局域生境的关系，阐明我国东部森林常见树木生长速率的分布规律及季节动态，揭示其影响因素及其区域分异。项目的实施将有助于理解树木生长的机制，为森林管理提供科学基础。

森林固碳是陆地生态系统碳循环的重要组分，树木生长是森林固碳的主要过程。树木生长是物种生活史策略、生长阶段、邻体作用、局域生境等因素综合作用的产物，不同因素对树木生长的影响会随时空尺度变化。研究森林树木生长的季节动态、分布格局及其控制因素，探讨不同因素对树木生长的影响及其区域分异，有利于促进理解森林固碳机制。项目在前期工作的基础上，采用生长环监测我国东部主要地带性森林的常见树木生长速率的季节动态，研究树木生长速率与功能性状、初始胸径、邻体作用及局域生境的关系。研究发现邻体相互作用对树木生长速率的影响具有时空尺度依赖，不同树木通过对资源适应的季节性差异来形成时间生态位分异；物种丰富度与生物量之间的关系依赖于环境的严酷程度；利用定位生物多样性操控实验，发现物种多样性则显著降低了树木生长对气候的敏感性；与保守性生存策略相联系的功能属性以及土壤养分降低了树木生长对气候的敏感性。研究阐明了我国东部森林常见树木生长速率的分布规律及季节动态，揭示了物种丰富度、功能属性和土壤养分在维持森林稳定性的作用。