采伐对幕布山区毛竹林土壤呼吸的影响

Effect of Cutting on Soil Respiration in Phyllostachy edulis Forest,Mubushan,China

利用LI-COR-8100土壤CO2通量自动测量系统测定了湖北赤壁幕布山区采伐毛竹林土壤表面CO2通量及5 cm深度的土壤温度、湿度,研究了采伐对毛竹林土壤呼吸的影响,并用壕沟法区分各组分呼吸。结果表明:采伐显著增加了毛竹林的土壤温度,但对土壤湿度无显著影响;采伐能增加土壤呼吸、凋落物呼吸与矿质呼吸,但降低了根系呼吸;土壤总呼吸及组分呼吸与土壤温度呈指数相关(R2=32.63%84.50%),与土壤湿度呈线性相关(R2=40.60%93.50%),运用土壤温度、湿度复合模型能提高预测土壤呼吸的准确性(R2=41.40%96.20%)。采伐毛竹林土壤呼吸的增加主要因为采伐后土壤温度升高所致。

To determine the effect of cutting on soil respiration in Phyllostachy edulis forest, Mubushan, Hubei Province, the soil surface CO2flux, soil temperature and moisture at the depth of 5 cm were measured by LI-COR- 8100 soil CO2 flux system, and the trenching method was applied to separate the soil respiration of source compo- nents. The result showed that the soil temperature increased significantly after cutting, but the soil moisture did not change significantly; the total soil respiration, litter respiration and mineral respiration elevated after cutting, but the root respiration decreased. The soil respiration and source components respiration were exponentially related with the soil temperature （ R^2 = 32.63% - 84. 50% ） and linearly related with the soil moisture （ R^2 = 40. 60% - 93.50% ） , respectively. However, the combined model of soil temperature and moisture could predict the variations of soil respiration more accurately （R^2 = 41.40% -96.20% ）. The increase of soil respiration mainly resulted from the increase of soil temperature after cutting.