祁连山土壤呼吸的时空变异及其与影响因子的关系

采用美国Li—cor公司生产的L16400-09土壤呼吸室连接到L16400便携式光合作用测量系统，对祁连山不同植被类型土壤呼吸速率进行了连续1年在生长季的野外测定，并通过多元回归手段对其影响因子进行了分析。结果表明：1）2003年生长季祁连山不同植被类型土壤呼吸速率的季节动态均为一单峰曲线，最大值出现在7月份；2）不同植被类型之间的土壤呼吸及其影响因子都存有一定程度的空间变异，且随着季节的变化，表现出一定规律性；其变异系数分别为：土壤呼吸速率在21．4％-72．18％之间，温度在12．00％-38．67％之间，土壤水分在32．17％．201．34％之间，地上生物量在72％左右；3）CO2释放速率、气温、土壤含水量和生物量之间的关系分析表明约有81％的土壤呼吸量变化是由气温、土壤水分和生物量共同决定的。

Soil CO2 Respiration and its Spatial and Temporal Variations as Affected by Biomass and Climate in Qilian Mountains

This one-year study of CO2 evolution from different type of vegetation soil using a LI6400-09 soil chamber connected to a LI6400 portable photosynthesis system in Qilian Mountains,examines seasonal trends and CO2 efflux in relation to biomass and climatic factors.The seasonal pattern of CO2 evolution rate had a single peak at July in 2003.Differences in the spatial variation of soil respiration and environment factors existed among the different com-munities,but the degree varied with the time of the season.Coefficients of variance the soil respiration ranged from 21.4% to 72.18%,temperature ranged from 12.00% to 38.67%,soil moisture ranged from 32.17% to 201.34%,and biomass coefficients of variance about 72%.Soil respiration was significantly correlated with air temperature,soil mois-ture and biomass,and there is 81% of soil CO2 efflux to decide together with them.