Phosphorus storage and allocation in vegetation on the Tibetan Plateau

Phosphorus (P) is critical for vegetation growth and ecosystem productivity. P distribution and allocation pat-terns 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 degrees 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.