The Contribution of Biological Soil Crust Carbon and Nitrogen Exchange to the Net Ecosystem Exchange Along an Elevation Gradient at the Sevilleta National Wildlife Refuge, New Mexico

The purpose of this project is to: 1.) determine how biological soil crust (BSC) cover changes along an elevation gradient and across seasons, 2.) determine how carbon and nitrogen exchanges of BSC communities vary with temperature along an elevation gradient in arid and semi-arid environments and, 3.) use photosynthetic and respiration rates of BSC communities to determine how the contribution of the BSC communities to whole ecosystem carbon exchange varies across the same gradient and over seasons.本项目的研究目标如下：1. 阐明生物土壤结皮（Biological Soil Crust, BSC）覆盖度沿海拔梯度的变化规律及其季节动态；2. 探明干旱半干旱环境中，生物土壤结皮群落的碳氮交换如何随温度及海拔梯度发生变异；3. 基于生物土壤结皮群落的光合与呼吸速率，解析其在对应海拔梯度与季节变化下，对整个生态系统碳交换的贡献程度。