吉林蛟河针阔混交林生物量时间稳定性驱动机制

The driving mechanism of biomass temporal stability of mixed coniferous and broad-leaved forest in Jiaohe,Jilin

生态系统稳定性是森林群落结构和功能的综合特征。通过长期大样地的监测数据,探究森林生态系统稳定性机制。本研究以吉林蛟河21.12 hm2天然针阔混交林固定样地中连续10年的野外调查数据(即2009年、2014年和2019年3次复测)为基础,分析了物种异步性、物种多样性、结构多样性、林分密度和海拔与生物量时间稳定性的直接和间接关系,探究并确定了生物量时间稳定性各驱动因素的相对重要性。结果显示,生物量时间稳定性与物种异步性、林分密度和海拔呈极显著正相关(P<0.001),路径系数分别为0.546、0.249和0.151。生物量时间稳定性与物种丰富度呈显著正相关(P<0.05),路径系数为0.086,而与林分结构的关系不显著(P>0.05),路径系数为0.021。海拔与林分密度呈显著正相关(P<0.001),路径系数为0.443,对生物量时间稳定性有极显著的间接作用。相较于其他林分因子,物种异步性是温带森林生物量时间稳定性的关键驱动因素,生物多样性通过物种异步效应提高生物量时间稳定性。基于结构方程模型的结果,分析生物与非生物因素对天然针阔混交林生物量时间稳定性影响的相对作用,对维持森林生态系统稳定性及森林可持续经营有重要现实意义。

Ecosystem stability is a comprehensive characteristic of forest community structure and function.The mechanism of forest ecosystem stability was explored using 10-year field survey data from a 21.12-hm2 natural coniferous and broad-leaved mixed forest plot in Jiaohe,Jilin Province(i.e.,three-time repeated in 2009,2014,and 2019).We analyzed the direct and indirect effects of species asynchrony,species diversity,stand density and elevation on temporal stability of aboveground biomass,and quantified their relative importance in driving temporal stability of aboveground biomass.The results showed that there was a significant positive correlation(P<0.001)between the biomass temporal stability and species asynchrony,stand density and elevation,with the path coefficients being 0.546,0.249,and 0.151.There was a significant positive correlation between biomass temporal stability and species richness(P<0.05),and the path coefficient was 0.086.There was no significant correlation between biomass temporal stability and stand structure(P>0.05),with a path coefficient of 0.021.There was a significant positive correlation between elevation and stand density(P<0.001),with a path coefficient of 0.443,which had significant indirect effect on biomass stability.Compared with other stand factors,species asynchrony was crucial in regulating biomass temporal stability.Biodiversity enhanced ecosystem stability through species asynchrony.Based on the results of structural equation modeling,we analyzed the relative effects of biotic and abiotic factors on the temporal stability of biomass in natural mixed coniferous and broadleaf forests,which is of practical significance for understanding forest ecosystem stability and forest sustainable management.