Cross-Site: Analysis of Past and Current Changes in Grassland Ecosystem Dynamics in Asia and North America

跨站点：亚洲和北美草原生态系统动态过去和现在的变化分析

基本信息

批准号：
9527303
负责人：
Dennis Ojima
金额：
$ 20万
依托单位：
Augustana University Association
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
1995
资助国家：
美国
起止时间：
1995-10-01 至 1999-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=9527303&HistoricalAwards=false
关键词：
Cross Site Analysis Past Current

项目摘要

We propose a three year project to investigate the role and consequences of changes in climate, land use, vegetation, and soils of the temperate grassland ecosystems of Asia and North America. The objective of this study is to characterize the factors controlling ecosystem integrity relative to changes in climate and land use of North American and Asian grasslands, and to understand these changes relative to the presence and distribution of C3 and C4 species in these two regions. Although plant productivity tends to be greater for the same amount of rainfall in the Asian continent, the occurrence of C4 species in the Asian grasslands is greatly reduced compared to the North American grasslands. They will incorporate isotopic analysis of soils and vegetation across a gradient of rainfall and temperature in Asia and compare these to similar analyses collected in North America. This information will be integrated using the CENTURY ecosystem model to investigate climate-soil-land use interactions on soil and vegetation dynamics. Isotopic signature 813C will be compared across sim ilar topo-edaphic positions of plant communities in different regions of the two continents. Remote sensing will provide the land cover template to evaluate the degree of changes from natural vegetation. These differences will be used in conjunction with the CENTURY model to evaluate net changes in ecosystem properties at the regional scale and the susceptibility of these grasslands to climate change and human activities.

我们提出了一个为期三年的项目，以调查亚洲和北美温带草原生态系统的气候、土地利用、植被和土壤变化的作用和后果。本研究的目的是描述控制生态系统完整性的因素与北美和亚洲草原气候和土地利用变化的关系，并了解这些变化与这两个地区 C3 和 C4 物种的存在和分布有关。尽管在相同降雨量的情况下，亚洲大陆的植物生产力往往更高，但与北美草原相比，亚洲草原中 C4 物种的出现量大大减少。他们将对亚洲降雨和温度梯度范围内的土壤和植被进行同位素分析，并将其与北美收集的类似分析进行比较。这些信息将利用 CENTURY 生态系统模型进行整合，以研究气候-土壤-土地利用对土壤和植被动态的相互作用。 813C 同位素特征将在两大洲不同地区植物群落的相似地形土壤位置上进行比较。遥感将提供土地覆盖模板来评估自然植被的变化程度。这些差异将与 CENTURY 模型结合使用，以评估区域尺度生态系统特性的净变化以及这些草原对气候变化和人类活动的敏感性。