集约经营措施对毛竹林生长季土壤呼吸的影响

摘要

以粗放经营毛竹Phyllostachys pubescens林和常绿阔叶林作为对照,利用静态箱-气相色谱法研究集约经营对 毛竹林土壤呼吸速率的影响.结果显示:整个生长季(4-10月),集约经营毛竹林、粗放经营毛竹林和常绿阔叶林之间土壤平均呼吸速率存在差异显著(P＜0.05),3种林分土壤平均呼吸速率分别为1.01,0.79和0.72 g·m-2·h-1.3种林分土壤呼吸速率动态变化规律基本一致,4-5月土壤呼吸速率相对较小,6月开始迅速升高,7月达到最大值,6-9月维持在较高值,10月开始大幅度下降.土壤呼吸与地下5 cm土壤温度呈显著的指数相关(P＜0.05),3种林分地下5 cm深处土壤温度分别可以解释土壤呼吸变化的63%,63%和59%.根据集约经营毛竹林、粗放经营毛竹林和常绿阔叶林土壤呼吸与地下5 Cm土壤温度拟合的指数方程,计算出生长季土壤呼吸的温度系数Q10值分别为2.46,4.81和2.05.图2表1参40%To examine the effects of intensive management practices on soil respiration, the soil respiration rate for three stand types: 1) intensively managed (IM) Phyllostachys pubescens, 2) traditional practices (TP) with P. pubescens, and 3) an evergreen broadleaved (EB) forest, was measured during the growing season with a closed chamber and gas chromatography. Results showed that the average soil respiration rate in the three stand types had significant differences (P＜0.05) with IM 1.01, TP 0.79, and EB 0.72 g·m-2·h-1.Soil respiration of the three stand types showed a similar pattern; namely, being low in April and May, rising rapidly in June, reaching a maximum in July, remaining high from June to September, and dropping dramatically in October. Significant exponential relationships(P＜0.05) between the soil respiration rate and soil temperature were found at the 5 cm depth. Also, soil respiration was IM = 63％, TP = 63％, and EB = 59％with temperature coefficient (Q10) values of IM 2.46, TP 4.81, and EB 2.05. [Ch, 2 fig. 1 tab.40 ref.]