摘要
本文对现有的区域植被动态模型进行了改进，改进后的模型包含了生态系统中生物量动态、植被结构动态、氮素循环过程三者之间的耦合，以及植被和土壤的相互作用。新模型的状态变量包括植被的绿色和非绿色生物量及其氮素浓度，３层土壤的水分，土壤的全氮和速效氮含量。利用全国范围内在过去数１０年中定点观测生物量、生产力、土壤全氮和速效氮的含量、卫星遥感植被指数、全国植被图、地形图、土壤图等多方面的基础数据，我们进行了模型的参数化工作，并对模型做了初步验证。结果说明本模型能够比较准确地模拟当前气候条件下植被的生物量、生产力和氮素吸收等动态过程。在此基础上，我们将改进后的模型用于中国陆地生态系统对全球变化响应的研究。为此我们采用了７个大气环流模型的输出的降水和温度的改变量和大气ＣＯ２浓度加倍条件，结合现有气候条件，生成未来气候变化情景（ｓｃｅｎａｒｉｏｓ），并用这些情景来驱动改进后的模型直到模型到达稳定状态。模拟结果说明：在未来气候变化条件下，温带常绿针叶林、亚热带山地常绿针叶林、落叶阔叶林、常绿阔叶林，典型禾草草原的分布将显著增加，而落叶针叶林、亚热带常绿针叶林、常绿灌木、禾草和半灌木草原、高寒禾草草甸的分布将有显著的下降，其他植?
We improved a previously developed regional model of vegetation dynamics to include biogeochemical cycling of nitrogen. Biomass and nitrogen concentration of green and non-green portions of vegetation, moisture contents of three soil layers, and total and available soil nitrogen, are included as state variables in the revised model. The model was applied to continental China and its two largest islands to investigate the responding characteristics of the ecosystems to global climatic change. Predicted future climate changes by seven general circulation models (GCM) were used to construct climatic scenarios to drive the model. The simulation predicted that broadleaf forests, temperate evergreen conifer forests, subtropical mountain evergreen conifer forests, and graminal steppes, would increase, but deciduous conifer forests, subtropical evergreen conifer forests, evergreen shrubs, graminal grass and short shrubs, and cold meadow steppes, would decrease. The rest of the vegetation classes seemed insensitive to climatic change. The simulation results also showed that the southern part of China with latitudes lower than 33° N have much larger increase in annual NPP(net primary productivity) than northern portuin of the transect. However, the predicted possible ranges of NPP changes in the northern transect is much larger than that of the southern portion, indicating more research effort should be made onto the northern ecosystems to reduce the uncertainty in their responses to global change.
出处
《第四纪研究》
CAS
CSCD
北大核心
2001年第4期281-293,共13页
Quaternary Sciences
基金
国家自然科学基金项目(批准号:39725006
39899370和39770133)
国家重点基础研究发展规划项目(批准号:G
关键词
气候变化
陆地生态系统
植被动态
净第一性生产力
中国
climatic change, terrestrial ecosystems, vegetation dynamics, net primary productivity
