集约经营措施对毛竹林生长季土壤呼吸的影响

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

Soil respiration during the growing season with intensive management of Phyllostachys pubescens

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（P0.05） 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（P0.05） 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.]