Leaf Nitrogen and Phosphorus Stoichiometry of Natural Plant Community and Restorable Plant Community in the Northern Qinghai-Tibet Plateau, China

The human engineering activities (highway, railway, cable, gas line and high line construction) has a negative impact on the alpine grassland ecosystem in the Qinghai-Tibet Plateau (QTP), and the natural restoration of plant community in land used for engineering construction is an important part of the rehabilitation of the degraded alpine grassland ecosystem. Previous studies have shown that the plant species and community diversity relationship in natural plant community and restorable plant community vary with the elevation (Guo et al. 2007) and restoration duration of land for engineering construction is more than 20 years at present (Ma et al. 2004). Understanding the mechanisms of plant species replacement in the process of plant restoration is important to restore the land used for engineering construction. The ecological stoichiometry is considered as an effective tool to disclose the inter-specific competition process and determine the succession trend (Güsewell 2004; Güsewell 2005; Yin et al. 2010). However, the stoichiometry relationship between natural plant community and restorable plant community is not well known yet. The objective of this study is to investigate the nitrogen (N) and phosphorus (P) stoichiometry of natural plant community and restorable plant community and its changes with elevation