非主要生长季节白桦人工林林隙内伐根对土壤呼吸速率的影响

Effect of Betula platyphylla Stump on Soil Respiration in Forest Gap during the Unimportant Growing Season

为研究伐根对林隙内土壤呼吸的影响,在非主要生长季节,选择具有不同腐朽程度的白桦伐根的林隙,采用LI-8100型土壤CO2排放通量全自动测量系统,对林隙内土壤呼吸速率进行了测定。同时,对影响土壤呼吸的主要因素——土壤温度、湿度和有机质含量进行了测定。结果表明:有伐根林隙土壤呼吸速率高于无伐根林隙土壤呼吸速率;有伐根林隙土壤呼吸速率呈现以伐根为中心向四周辐射,土壤呼吸速率以由高变低、再变高的规律变化;有伐根林隙随伐根腐朽程度的不同,土壤呼吸速率空间异质性变化梯度最大值降低;伐根的腐朽程度是影响有伐根林隙土壤呼吸速率的主要因素。

Soil respiration rate was measured in the forest gap with Betula platyphylla stumps rotted in different levels using the LI-8100 automated soil CO2 flux system in order to study the influence of stumps on soil respiration during the unimportant growing season.Some influencing factors such as soil temperature,moisture and organic matter were measured simultaneously.Results showed that soil respiration rate in the gap with stumps was higher than that in the gap without stumps.Soil respiration rate in the gap with stumps radiated from the stump and exhibited a changing tendency of high-low-high.The maximum value of varying gradient for spatial heterogeneity of soil respiration rate decreased with rotten degree of stumps.Rotten degree of stump is an important factor affecting soil respiration in forest gap.