极端干旱对毛竹林土壤呼吸的影响

为了预测未来气候变化引起的干旱和高温对森林碳循环的影响,采用人工截雨的方法,创造极端干旱环境,研究极端干旱和较高土壤温度对人工毛竹林土壤呼吸的影响。结果表明：（1）人工截雨样地和对照样地的土壤呼吸月际变化分别为0.63~2.00μmol/（m2·s）和0.66~2.20μmol/（m2·s）。土壤呼吸的月际变化与土壤温度的变化趋势基本相同,而与土壤含水量的变化趋势相反,即成负线性相关。（2）土壤温度可以分别解释截雨样地和对照样地土壤呼吸变异的65.5%和73.9%。基于耦合土壤温度和土壤含水量的多元线性模型,可以分别解释截雨样地和对照样地土壤呼吸变异的66.9%和73.4%。土壤含水量与土壤呼吸的关系不紧密。截雨样地和对照样地的Q10值分别为4.44和5.99。

Effects of Extreme Drought on Soil Respiration in the Phyllostachys pubescens Forest

In order to predict the effect of drought and high temperature on forest carbon cycling in the context of climate change,a throughfall exclusion experiment was carried out to explore effects of increased soil temperature and decreased soil water content on soil respirations in the bamboo forest in north Zhejiang of China.The results showed that：（1） monthly variation in soil respiration ranged from 0.63 to 2.00 μmol/（m2·s） and 0.66 to 2.20 μmol/（m2·s） in throughfall exclusion and control plots respectively.The soil respiration monthly variation followed the monthly variation of soil temperature and in contrast to the monthly variation of the soil water content.（2） Soil temperature could explain 65.5% and 73.9% of the variance of soil respiration in throughfall exclusion and control plots respectively.Multivariate linear model based on temperature and soil water content explained 66.9% and 73.4% of the variance of soil respiration in throughfall exclusion and control plots respectively.Soil water content had no significant relationship with soil respiration.Q10 values of throughfall exclusion and control plots were 4.44 and 5.99.