敦煌南湖湿地植物-土壤碳氮磷化学计量比空间格局分异规律研究

全球变化与人类活动所引发的湿地水文情势改变和盐分聚集深刻影响着湿地生态系统的稳定和健康，导致湿地植物元素微观组成的化学计量学特征发生变异，进而对湿地生态系统化学计量学空间格局产生影响。植物个体的元素组成特征对外界环境变化具有指示作用，可作为研究湿地生态系统化学计量学特征对环境因子响应机制的关键切入点。项目以敦煌南湖湿地-敦煌阳关国家级自然保护区植被为研究对象，依据生态化学计量学原理，运用环境因子定位监测和植物-土壤碳氮磷元素含量的实验测定方法，揭示干旱区不同退化阶段的湿地植被-土壤化学计量学时空分异特征及植物生长的限制元素，探讨退化植被的化学元素动态及对土壤水盐梯度变化的响应，构建干旱区湿地不同生态层次属性的化学计量学基础，为植被-土壤-水盐环境因子的关系研究提供科学依据，为西北干旱区内陆河流域湿地的水文管理、盐分调控和植被恢复提供决策支持，保障区域湿地生态-经济社会系统的协调可持续发展。

Changes in hydrological regimes and salinity caused by global change and human activities have a profound influence on the stability and health of wetland ecosystems. They result in variation of elements microscopic composition for stoichiometric characteristics in wetland plants, and then impact on spatial pattern of stoichiometry in wetland ecosystem. There is the indication effect of elemental composition in individual plant with the changes of external environment. Therefore, the individual plant can be a critical entry point study on stoichiometry response mechanism to environmental factors in wetland ecosystems. Taking Nanhu lake wetland vegetation of Dunhuang city in Dunhuang Yangguan National Nature Reserve as research objects, according to the principles of ecological stoichiometry, spatiotemporal variation characteristics of wetland plant-soil stoichiometry and limitations of the elements for plant growth in different degradation stages of arid area will be revealed using the methods for the location monitoring environmental factors and the experimental determination of carbon, nitrogen and phosphorus content in plant-soil. The chemical element dynamics of degradation vegetation and response to the gradients of soil water and salinity will be explored. The foundation of stoichiometry based on the different ecological level attributes in wetland will be developed. This project will be to provide the scientific basis for studying on the relationship among vegetation, soil, water and salinity factors, and the decision making for management of wetland hydrology, salinity control and vegetation restoration in arid inland river basins of northwest China, ensuring the regional sustainable development in wetland ecological - economic - social system.