干旱区研究2025，Vol.42Issue(12)：2268-2277,10.DOI:10.13866/j.azr.2025.12.10
内蒙古锡林郭勒两种灌丛化草原的沃岛效应
Fertile island effect characteristics of two types of shrub-encroached grasslands in Xilingol,Inner Mongolia
摘要
Abstract
Shrub encroachment is widespread in arid and semi-arid regions,and it produces a fertility island ef-fect,whereby soil nutrients under shrub patches become enriched,thereby influencing ecosystem nutrient cycling and structural stability.We selected 17 shrub-encroached grassland sites in typical grassland and desert-steppe re-gions of Xilingol League,Inner Mongolia and analyzed the soil stoichiometry of carbon(C),nitrogen(N)and phosphorus(P).By combining climatic data with structural equation modeling,we examined the characteristics of the fertility island effect under the two grassland types and the influence of climatic factors.Following shrub encroachment,C,N,and P concentrations under shrub patches were significantly higher than those in the herba-ceous matrix(all P<0.05),indicating a pronounced fertility island effect.The relative interaction intensity(RII)of the fertility island effect was greater in the typical grassland region than in the desert-steppe region,with signifi-cant between-region differences in the RIIs of ammonium nitrogen(NH4+-N),nitrate nitrogen(NO3--N),and avail-able P(P<0.05).The RIIs of different soil elements exhibited non-linear responses to mean annual temperature(MAT)and mean annual precipitation(MAP).In the typical grassland region,the RIIs of NH4+-N,NO3--N and available P increased significantly with MAT(all P<0.05),whereas in the desert-steppe region,these RIIs signifi-cantly decreased with increasing MAT(all P<0.05).The relationships of the RIIs of these three elements with MAP exhibited opposite patterns to those with temperature.Excluding the RII of available P,which was negative-ly correlated with aboveground biomass,the RIIs of the other elements were positively correlated with aboveg-round biomass.This study elucidated the fertility island effects induced by shrub encroachment and their relation-ships with climate and grassland type,providing a scientific basis for the ecological restoration of shrub-en-croached grasslands and management of C,N,and P biogeochemical cycles.关键词
灌丛化草原/沃岛效应/土壤元素/相对作用强度/内蒙古Key words
shrub-encroached grasslands/fertile island effect/soil elements/relative interaction intensity/In-ner Mongolia引用本文复制引用
FAN Shuxiang,GUO Jinyan,LI Huanhuan,LI He..内蒙古锡林郭勒两种灌丛化草原的沃岛效应[J].干旱区研究,2025,42(12):2268-2277,10.基金项目
国家自然科学基金面上项目(32271958) （32271958）
江苏省大学生创新训练计划项目(202410320002Z) （202410320002Z）
