林业科学2026，Vol.62Issue(9)：28-41,14.DOI:10.11707/j.1001-7488.LYKX20260079
晋西黄土区典型人工林树种和林分密度对土壤呼吸及其温度敏感性的影响
Effects of Tree Species and Stand Density on Soil Respiration and Its Temperature Sensitivity in Typical Plantations on the Loess Plateau of Western Shanxi Province
摘要
Abstract
[Objective]The objective of this study is to reveal the characteristics of soil respiration rate(RS)and soil respiration temperature sensitivity index(Q10)under different tree species and stand density conditions in plantations in the Loess Plateau of western Shanxi Province,and identify the key driving factors,so as to provide a scientific basis for plantation management and parameter optimization of carbon cycle models in this region.[Method]Five stand density gradients were selected in pure Robinia pseudoacacia and Pinus tabuliformis plantations.The densities were 900,1 200,1 500,1 800,and 2 400 trees·hm-2 for R.pseudoacacia,and 900,1 200,1 800,2 400,and 2 800 trees·hm-2 for P.tabuliformis.A LI-8100 soil carbon flux monitoring system was used to continuously measure RS during the growing season(from May to October,2024).Soil physicochemical properties,soil microbial characteristics,as well as litter standing crop,litter carbon content,fine root biomass density,and carbon,nitrogen and phosphorus contents of fine roots simultaneously determined.Q10 was estimated using an exponential model,and the main driving mechanisms underlying the variation in RS and Q10 were further elucidated.[Result]1)After controlling for soil temperature,soil water content,and month,tree species significantly affected RS.The RS in the P.tabuliformis plantations[(3.47±0.17)μmol·m-2s-1]was significantly higher than that in the R.pseudoacacia plantations[(3.02±0.09)μmol·m-2s-1].The Q10 of P.tabuliformis plantations(3.23±0.26)was also numerically higher than that of R.pseudoacacia plantations(2.50±0.13).2)As the forest density increased,RS in the two plantations increased,but there were no significant differences in RS among different density treatments within each species.The response of Q10 to stand density differed between the two species.There was no significant difference in Q10 among different density treatments in R.pseudoacacia plantations,while in P.tabuliformis plantations,Q10 values at the density of 2 800 trees·hm-2 was significantly higher than that at 1 200 trees·hm-2(P<0.05).3)Correlation analysis indicated that soil clay content and litter standing crop were key drivers for variation in RS,and plant litter traits,fine root traits,and soil microbial properties played central roles in fluctuations in Q10 values.[Conclusion]Soil respiration and soil respiration temperature sensitivity index in plantations are jointly regulated by tree species and stand density.Specifically,the characteristics of plant litter,fine root,and soil microorganisms are the key factors driving the temperature response of soil carbon release.Tree species influence soil respiration primarily through differences in the quantity and quality of litter input.P.tabuliformis plantation has larger litter standing crop and higher carbon content,providing more abundant substrates for microbial respiration,resulting in overall higher RS and Q10 values than R.pseudoacacia plantations.The effect of stand density on soil respiration ias species-dependent:Q10 values remains stable across density classes in R.pseudoacacia plantation,while the high-density P.tabuliformis stands have sufficient substrates,and the microbial metabolism is more sensitive to temperature,jointly driving a significant increase in Q10 values.This study deepens understanding of changes in soil carbon flux and the mechanisms underlying its temperature response in plantations,and provides a theoretical basis for density regulation and structural optimization of plantations.关键词
土壤呼吸/温度敏感性/人工林树种/林分密度Key words
soil respiration/temperature sensitivity/plantation tree species/stand density分类
农业科技引用本文复制引用
罗鸿,许行,张晓花,张志强..晋西黄土区典型人工林树种和林分密度对土壤呼吸及其温度敏感性的影响[J].林业科学,2026,62(9):28-41,14.基金项目
国家自然科学基金项目(32271967,32301664) （32271967,32301664）
中国科协青年人才托举工程(YESS20230091) （YESS20230091）
北京林业大学科技创新计划项目(JCYJ202507). （JCYJ202507）
