岩溶表层带土壤温度和含水率对呼吸作用的影响

Effects of soil temperature and moisture on soil respiration in epikarst

全球环境变化对岩溶区的碳循环产生重要的影响，而土壤呼吸作用在全球环境变化的影响和反馈的过程中具有十分重要的作用。因此，以岩溶区的岩溶表层带为研究对象，研究了土壤呼吸作用与土壤温度和大气降水量之间的响应机理和内在联系。研究结果表明：岩溶表层带的土壤呼吸作用具有单峰型的季节性变化特征。洼地0~5、10~20 cm 的土壤呼吸速率在范围变化分别为82.58 mg· m-2· h-1至412.89、151.39 mg· m-2· h-1至523 mg· m-2· h-1，最大值出现在8月中旬。坡地0~5、10~20 cm的土壤呼吸速率在范围变化55.05 mg· m-2· h-1至412.89、137.63 mg· m-2· h-1至495.47 mg· m-2· h-1，最大值出现也在8月中旬。洼地的土壤呼吸作用相对强于坡地，主要是由于坡地土壤相对洼地土壤较薄并且容易被降水冲刷搬运。在大气降水量不成为限制土壤呼吸作用的因子下，土壤温度为主要控制土壤呼吸作用的因子。因此，该研究可为控制土壤呼吸作用缓和大气CO2的升高和温室效应应对策略，为国家固碳减排的科学决策提供理论依据。

Global environmental change play an important impact on the carbon cycle in karst area, and soil respiration specifically affect and feedback to global environmental. Therefore, the paper discussed the relationship between soil respiration and soil temperature and atmospheric precipitation in epikarst zone. The monitor results indicated that： soil respiration has single peak seasonal variations. Depressions 0-5, 10-20 cm of soil respiration rate in the range of variation was from 82.58 mg· m-2· h-1 to 412.89, 151.39 mg· m-2· h-1 to 523 mg· m-2· h-1. The maximum value was in mid-August. Slopes 0-5, 10-20 cm of soil respiration rate changes in the range from 55.05 mg· m-2· h-1 to 412.89, 137.63 mg· m-2· h-1 to 495.47 mg· m-2· h-1. The maximum value occurred also in mid-August. Soil respiration in depression relatively stronger than in the slopes, mainly caused by the relatively low-lying land sloping soil is thin and easy to erosion handling by precipitation. If precipitation in the atmosphere does not become a limiting factor in summer soil respiration, soil temperature as the main control of soil respiration. Therefore, this paper recommend on controlling of soil respiration to ease elevated atmospheric CO2 and the greenhouse effect coping strategies, and emission reduction for the state to provide a theoretical basis for scientific decision-making.