氮沉降增加影响南亚热带森林优势树种磷吸收策略的机理

土壤中有效磷缺乏是限制南亚热带森林植被生长的重要因素。氮沉降增加可以影响根形态结构、菌根共生体的形成以及根际和菌根际的酸性磷酸酶活性，从而影响植物对磷的吸收。然而不同树种对氮沉降增加的响应和适应策略存在差异。本项目把野外观测与室内栽培试验相结合，利用根和磷酸酶活性原位可视化技术，研究南亚热带森林优势树种根系、菌根共生体、酸性磷酸酶活性及其空间分布对氮沉降增加的响应，阐明不同树种对氮沉降增加响应差异的原因；明晰氮沉降不断增加条件下，树木高效吸收磷的地下部分特征，从而揭示氮沉降增加影响植物磷吸收策略的机理。研究结果有助于评估氮沉降增加对南亚热带森林植被生长及潜在植物群落组成变化的影响。

Phosphorus deficiency is the main factor inhibits plant growth in south subtropical forest. Nitrogen deposition elevation could affect root morphology and architecture, the formation of mycorrhizal symbiosis and the acid phosphatase activity in the rhizosphere and mycorrhizosphere. However, the responses and adaption strategies to elevated N deposition were varied between tree species. In this project, we combine field with greenhouse cultivation experiment, using the root and acid phosphatase activity visualization techniques to study N deposition elevation effect on the root, mycorrhizal symbiosis, the spatial distribution and in situ activity of acid phosphatase activity of dominant tree species in south subtropical forest. This study aims to find out the reason tree species have varied response to elevated N deposition and try to clarify the below-ground properties plants should have to assimilate phosphorus with high efficiency under elevated N deposition condition. Therefore, this study can reveal the impact of elevated N deposition on the mechanism of P assimilation. Our results will be helpful to evaluate N deposition elevation effects on plant growth and the potential plant community composition of the south subtropical forest.