增温对南亚热带常绿阔叶林植物磷素获取的影响机理

气候变暖使热带、亚热带森林碳汇功能发生改变的方向存在很大的不确定性，究其原因与该地区植物是否受到磷素的限制相关。基于磷素的纬度地带性分布规律和热带、亚热带森林生产力特征，植物磷素获取在增温过程中的变化方向和程度可能是调控该地区森林碳汇对气候变暖反馈的关键要素。本项目基于鼎湖山大型增温实验平台，结合宏观质量平衡法、光谱分析和磷酸盐氧同位素观测法，研究增温对南亚热常绿阔叶林生态系统水平植物磷素利用和土壤磷素供应的影响及其权衡关系，从而进一步阐明植物磷素获取的响应机理。研究结果有助于了解增温背景下磷素调控南亚热带森林碳汇功能变化的规律，为未来森林生态效益评估和“碳中和”相关政策的制定提供科学支撑。

The change direction of carbon sink of tropical and subtropical forests due to climate warming is uncertain, which may be related to whether plants in these forests are limited by phosphorus (P). Considering the latitudinal distribution pattern and productivity characteristics of P in tropical and subtropical forests, the direction and extent of change in plant P acquisition under warming may be the key in regulating the feedback of carbon sinks to climate warming. Based on the long-term experiment of rising air temperature at the Dinghushan Forest Ecosystem Research Station, by using mass balance approach, spectroscopic and isotopic techniques, this project aims to study the effects of warming on plant P utilization and soil P supply and their relationships, and to reveal biochemical mechanisms of plant P acquisition. Implement of this project would increase the understanding of P regulating change of carbon sink under warming and provide scientific basis for the evaluation of forest ecological benefits and formulation of Carbon Neutral policy.