生态学杂志2025，Vol.44Issue(1)：56-64,9.DOI:10.13292/j.1000-4890.202501.022
氮添加对杨树地上和地下生物量增加的直接和间接效应
Direct and indirect effects of nitrogen addition on the increase of above-and below-ground biomass of pop-lar
摘要
Abstract
The increase of plant biomass caused by nitrogen(N)addition is one of the important factors to enhance carbon sequestration potential of plants.At present,the effects of direct and indirect interactions between plants,soil,and microorganisms under N addition on the above-and below-ground carbon sequestration(C)function of forests are unclear.We used structural equation models to analyze the direct and indirect effects of leaf and fine root chemical traits,soil microbial community and soil physicochemical factors on above-and below-ground biomass in-crease of poplar 107(Populus euramericana cv.'74/76')saplings under four N input levels(no N addition,ad-ditions of 50,100,and 200 kg·hm-2·a-1 urea).The results showed that with the increases of exogenous N in-put,the increase of aboveground biomass was greater than that of belowground biomass,resulting in a decrease of root-shoot ratio.The increase of N input significantly increased leaf N concentration and decreased leaf C concentra-tion,resulting in the decrease of leaf C∶N,but the effect on the chemical traits of fine roots was limited.The in-crease of N input did not affect rhizosphere soil microbial community.The structural equation modeling showed that the direct and indirect factors affecting above-and below-ground biomass were consistent,i.e.,exogenous N input,leaf C and leaf N had direct effects,while NH4+-N,NO3--N content,and leaf N had indirect effects.Our results clarified the direct or indirect interactions among plants,soil and microorganisms,providing a scientific basis for evaluating the effects of N addition on the above-and below-ground carbon sequestration of poplar plantations.关键词
氮添加/杨树/植物性状/生物量/结构方程模型/效应Key words
nitrogen addition/poplar/plant traits/biomass/structural equation model/effects引用本文复制引用
闫香如,李品,吴贤杰,孙语倩..氮添加对杨树地上和地下生物量增加的直接和间接效应[J].生态学杂志,2025,44(1):56-64,9.基金项目
国家自然科学基金项目(32271673)资助. （32271673）
