我国温带草原的灌丛化及其对生态系统结构和功能的影响

项目名称： 我国温带草原的灌丛化及其对生态系统结构和功能的影响

项目编号： No.31330012

项目类型： 重点项目

立项/批准年度： 2014

项目学科： 生物科学

项目作者： 方精云

作者单位： 北京大学

项目金额： 323万元

中文摘要： 草原的灌丛化在全球范围尤其在干旱半干旱地区普遍发生，灌丛化草原已成为一种重要的植被类型。灌丛化深刻改变群落的物种组成，引起生态系统结构和功能的变化，但目前人们对这一植被类型的分布、形成机制及其生态学影响都缺乏足够的认识。本项目拟以内蒙古灌丛化草原为主要研究对象，结合我国其他温带地区草原灌丛化的调查，采用航片/遥感解译、野外群落及环境因子调查、典型地区灌丛化草原的定位测定和控制实验等方法和手段，基本查明我国温带地区灌丛化草原的分布、物种组成及其区域分异，阐明灌丛化对群落多样性和生态系统碳收支的影响，揭示灌丛化草原发生发展的机制及对水肥变化的响应。本项目的实施，将加深人们对灌丛化草原的认识，丰富植被理论；为揭示温带干旱半干旱地区草原灌丛化的形成机制和草地沙化、退化机理，增强生态系统的碳汇功能，促进该地区农牧业的可持续利用提供基础数据和科学依据。

中文关键词： 灌丛-草原连续体;分布格局;生物多样性;碳收支;全球变化

英文摘要： The encroachment of shrubs into grasslands has been a widespread phenomenon across the world, especially in arid and semiarid regions. As an important and novel vegetation type, shrub encroachment could substantially alter species composition of original grassland communities and cause changes in ecosystem structure and function. However, the distribution patterns, formation mechanisms, and ecological impacts of shrub encroachment still remain large uncertainties. Using aerial photos/remote sensing, community survey, control experiments at typical shrub encroached-grasslands, and model simulation, we will conduct a field study across arid and semiarid grasslands in China, mainly focused on shrub encroached-grasslands in Inner Mongolia, to answer above questions. Specifically, we aim to 1) identify the distribution pattern, species structure, and regional differentiation of shrub encroachment, 2) clarify the effects of shrub encroachment on community diversity and ecosystem carbon budget, and 3) reveal the formation mechanisms of shrub encroachment and its response to global climate change. The implementation of this project will enhance our understanding on shrub encroachment, and enlarge the vegetation theory. In addition, the implementation of this project will clarify the ecosystem response to global climate change, protect regional biodiversity, enhance the magnitude of carbon sink, and finally provide the scientific insight and basic data for the sustainable use of grasslands in China’s temperate arid and semi-arid regions.

英文关键词： shrub-grassland continuum;distribution pattern;biodiversity;carbon budget;climate change