Bedrock determines the elevational patterns of soil phosphorus pools in a subtropical karst forest

Soil phosphorus (P) is an important nutrient limiting the plant productivity. The elevational pattern of soil P concentration is widely used to indicate how it responds to the climatic gradient. However, the bedrock variation in an elevational transect is usually neglected, which could have caused the inconsistent elevational patterns of soil P concentration in previous studies. In present study, we examined elevational patterns of various soil P pools (i.e., labile inorganic P (Pi) and organic P (Po), moderately labile Pi and Po, primary mineral P, and occluded P) in top-soils in an elevational transect with alternating bedrock types (i.e., clasolite and limestone) in a subtropical karst forest.

土壤磷（P）是限制植物生产力的重要营养元素。土壤磷浓度的海拔格局被广泛用于指示其对气候梯度的响应规律。然而，海拔样带内的基岩差异通常被忽视，这可能导致既往研究中土壤磷浓度海拔格局的不一致性。本研究以亚热带喀斯特森林中一条基岩类型交替出露（即碎屑岩与石灰岩）的海拔样带为研究对象，分析了表层土壤中各类土壤磷库的海拔分布格局，所涉及的磷库包括活性无机磷（labile inorganic P, Pi）、有机磷（organic P, Po）、中活性无机磷与有机磷、原生矿物磷以及闭蓄态磷。