目前有关喀斯特生态退化区高钙（Ca）、高pH对植物磷（P）素利用效率影响的理解大多停留在样地水平层面，对于大尺度下植物响应机制方面的了解相对较少，因此尚无法确切解释土壤化学要素干扰乡土植物天然分布的原因。本项目拟以我国贵州省内已退化的喀斯特地区为研究区域，以生态环境相对较好的地区为对照区，以当地3个药用草本植物种类为对象，通过野外大尺度的样地调查得出土壤Ca、pH、P和植物指标的空间分布格局并分析二者间相关性，另通过室内控制试验的手段研究植物叶片的光合、气孔导度和根系的P素离子流动力学特征和异质性觅P行为，以此揭示宏观尺度上影响植物P素有效性的关键机制，为喀斯特地区退化生态系统中植被的恢复提供理论参考

Current understanding about the impact of high calcium (Ca) and pH on low phosphorus (P) utilization in endemic plants of ecology-degraded Karst region is mainly derived from micro-scale site studies, but less information is aware about inherent mechanism at large scale. It is hard to fully explain the interference of soil chemical factors to the distribution of endemic plants in Karst regions. In the current project plan, ecology-degraded Karst regions in Guizhou Province, China, were chosen as the objective research area with comparison to the other region with much better ecological status. Therein, three endemic species of medicinal herbs were investigated and sampled for their growth, biomass, and Ca and P contents in shoot and root parts. Meanwhile, soil parameters of Ca and P contents and pH value were also investigated within the same plots of sampled plants. Both distribution patterns of plant and soil parameters were detected separately whose relationship with each other, however, was detected thereafter..Sampled plants were planted in pots placed in controlled environment to measure their foliar photosynthetic rate and gas exchange and P-uptake kinetics and foraging behavior in heterogeneous P patches by roots, which can help to determine the mechanism for P utilization in medicinal herbs distributed at large field scale. Data from this project plan would supply theoretical reference for the protocol of vegetation restoration of ecology-degraded Karst regions of China.