N-fixing tree species promote the chemical stability of soil organic carbon in subtropical plantations through increasing the relative contribution of plant-derived lipids  

作　　者：Xiaodan Ye Junwei Luan Hui Wang Yu Zhang Yi Wang Shirong Liu 

机构地区：[1]College of Coastal Agricultural Sciences,Guangdong Ocean University,Zhanjiang 524088,China [2]Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration,Ecology and Nature Conservation Institute,Chinese Academy of Forestry,Beijing 100091,China [3]Institute of Resources and Environment,International Centre for Bamboo and Rattan,Key Laboratory of National Forestry and Grassland Administration/Beijing for Bamboo&Rattan Science and Technology,Beijing 100102,China

出　　处：《Forest Ecosystems》2024年第5期758-769,共12页森林生态系统（英文版）

基　　金：supported by the National Natural Science Foundation of China(31930078,32301559);the Ministry of Science and Technology of China(2021YFD2200405,2021YFD2200402);Fundamental Research Funds of CAF(CAFYBB2021ZW001);the program for scientific research start-up funds of Guangdong Ocean University。

摘　　要：Biodiversity experiments have shown that soil organic carbon(SOC)is not only a function of plant diversity,but is also closely related to the nitrogen(N)-fixing plants.However,the effect of N-fixing trees on SOC chemical stability is still little known,especially with the compounding effects of tree species diversity.An experimental field manipulation was established in subtropical plantations of southern China to explore the impacts of tree species richness(i.e.,one,two,four and six tree species)and with/without N-fixing trees on SOC chemical stability,as indicated by the ratio of easily oxidized organic carbon to SOC(EOC/SOC).Plant-derived C components in terms of hydrolysable plant lipids and lignin phenols were isolated from soils for evaluating their relative contributions to SOC chemical stability.The results showed that N-fixing tree species rather than tree species richness had a significant effect on EOC/SOC.Hydrolysable plant lipids and lignin phenols were negatively correlated with EOC/SOC,while hydrolysable plant lipids contributed more to EOC/SOC than lignin phenols,especially in the occurrence of N-fixing trees.The presence of N-fixing tree species led to an increase in soil N availability and a decrease in fungal abundance,promoting the selective retention of certain key components of hydrolysable plant lipids,thus enhancing SOC chemical stability.These findings underpin the crucial role of N-fixing trees in shaping SOC chemical stability,and therefore,preferential selection of N-fixing tree species in mixed plantations is an appropriate silvicultural strategy to improve SOC chemical stability in subtropical plantations.

关 键 词：Tree species diversity Soil organic carbon N-fixing tree species Hydrolysable plant lipids Lignin phenols 

分 类 号：S714.2[农业科学—林学]