荒漠草原沙漠化对植物和土壤C、N、P化学计量特征的影响

由于人类对草地资源的过度利用和全球气候变化，造成草地生态系统不同程度的退化与沙漠化，宁夏中北部荒漠草原严重的退化/沙漠化已成为中国北方主要的生态环境问题。本项目拟以生态化学计量学理论和方法，分析荒漠草原沙漠化对土壤、植物C、N、P生态化学计量特征及土壤-植物生态化学计量特征之间关系的影响，旨在探讨荒漠草原沙漠化过程中土壤、植物C、N、P元素及其化学计量的演变特征和规律，并从生态化学计量学的角度揭示荒漠草原沙漠化对土壤-植物系统中C、N、P生态化学计量交换过程与格局的影响机制、荒漠草原生态系统C、N、P元素之间的相互作用及平衡制约关系，其结果有助于重新认识植被组成与格局、荒漠草原退化与恢复演替机理，以期为防止沙漠化及沙漠化草地生态系统的恢复和重建提供理论依据。

The disturbance of human activities and global climate change have made the grassland ecosystem degradation/desertification in different degree, and grassland degradation/desertification has become the most serious ecological environment problem in northern China. In semi-arid desert steppe of Ningxia, the effect of grassland desertification on C, N, P stoichiometry characteristics of plant and soil and the relationships of stoichiometry between plant and soil will be studied by using ecological stoichiometry theory and method. The study will explore evolution characteristics and regularity of C, N, P and its stoichiometry characteristics of plant and soil in the desertification process of desert steppe, and reveal the effect of desertification on C, N, P stoichiometry exchange process and pattern between plant and soil, interaction among C, N and P in desert steppe ecosystem from the perspectives of stoichiometry. The study is help to understanding composition and pattern characteristics of vegetation, degradation and recovery succession mechanism of desert steppe, and provide theoretic foundation for preventing desertification and restoration of sandy grassland ecosystem.