Phosphorus storage and allocation in vegetation on the Tibetan Plateau

Abstract

Phosphorus (P) is critical for vegetation growth and ecosystem productivity. P distribution and allocation patterns of plants in natural communities are associated with their resource allocation strategies. However, owing to the lack of systematic research, the spatial variations of vegetation P on the Tibetan Plateau (TP) remain unclear. Based on the 0.5° standardized spatial grid sampling method and survey data obtained from plant organs (leaf, branch, trunk, and root) in 2,040 plant communities, we analyzed the distribution of vegetation P contents (g kg−1) and densities (g P m−2) on the TP. The results indicate that the vegetation P contents and densities differed significantly among the plant organs on the TP. Active organs contained higher P contents but lower P densities. Radiation dominated vegetation P storage and allocation on the TP. Strong radiation had a negative effect on vegetation P accumulation and caused more P to be allocated to the underground parts. The TP vegetation stored approximately 3.64 Tg of P, of which approximately 1.68, 1.28, 0.68, and 0.01 Tg of P were stored in forests, shrublands, grasslands, and deserts, respectively. Based on a large survey dataset, we determined the spatial distributions of vegetation P and constructed a P density distribution map for TP vegetation, which can be used for ecosystem modeling.

Keywords

• Tibetan Plateau
• Vegetation
• Phosphorus content
• Phosphorus storage
• Influencing factors