干旱区研究2025，Vol.42Issue(2)：274-288,15.DOI:10.13866/j.azr.2025.02.08
林分密度对刺槐人工林土壤养分和微生物群落的影响
Effects of stand density on soil nutrients and microbial communities in Robinia pseudoacacia plantations
摘要
Abstract
Soil nutrient levels and microbial community structures are critical indicators for evaluating the eco-system services of artificial forests.In arid and semi-arid regions,which are the major distribution areas for arti-ficial forests,the regulatory effects of stand density on soil nutrients and microbial communities remain poorly understood.This study analyzed a 30-year-old Robinia pseudoacacia plantation on the Loess Plateau's eastern edge.Based on Reineke's stand density effect law and regional management standards,the stands were catego-rized into low(950-1350 trees·hm-2),medium(1600-2050 trees·hm-2),and high(2400-3300 trees·hm-2)densi-ty groups.Data were collected through field surveys,soil nutrient analyses,and high-throughput sequencing of 16S rRNA and ITS.These methods systematically assessed the soil nutrient characteristics and microbial commu-nity structures and diversity across different stand densities.The study's findings indicate that as the stand densi-ty increases,the soil total nitrogen,nitrate nitrogen,total carbon,and organic carbon contents significantly in-crease,especially in the high-density group(P<0.05).Conversely,the available phosphorus content peaks in the medium-density group.The bacterial community was primarily composed of Proteobacteria(38.70%),Actinobac-teria(19.37%),Gemmatimonadetes(8.23%),and Chloroflexi(7.71%),with Actinobacteria's relative abundance significantly increasing alongside the stand density(P<0.05).In the fungal community,Ascomycota(51.79%),Mortierellomycota(30.70%),and Basidiomycota(10.07%)were the dominant phyla.In the high-density group,bacterial and fungal community diversity was significantly enhanced,as evidenced by notable increases in the Shannon and Chao1 indices(P<0.05).Principal Coordinates Analysis revealed that the bacterial community struc-tures in the medium-and low-density groups exhibited significant clustering,distinctly differing from those in the high-density group(P<0.05).In contrast,the fungal community structures remained relatively stable across dif-ferent stand densities.The Mantel test revealed that bacterial and fungal community structures were significantly associated with TN(P<0.05).Cooccurrence network analysis indicated that moderate stand density increases mi-crobial interaction strength and network complexity.However,when the stand density exceeded 2400 trees·hm-2,the network stability decreased,potentially hindering efficient resource utilization.Maintaining a stand density of 1600-2050 trees·hm-2 improves soil nutrient levels and enhances microbial community diversity and stability,providing a scientific basis for the sustainable management of R.pseudoacaciaplantations on the Loess Plateau.关键词
林分密度/刺槐人工林/土壤养分/微生物群落/干旱半干旱地区Key words
stand density/Robinia pseudoacacia plantations/soil nutrients/microbial community/arid and semi-arid regions引用本文复制引用
张佳凝,张建军,赖宗锐,赵炯昌,胡亚伟,李阳,卫朝阳..林分密度对刺槐人工林土壤养分和微生物群落的影响[J].干旱区研究,2025,42(2):274-288,15.基金项目
国家重点研发计划基金(2022YFF130040103) （2022YFF130040103）
