干旱区荒漠灌木林地土壤呼吸及其影响因素分析

沿三工河流域山前丘陵、冲-洪积平原绿洲及北部荒漠的过渡区测定了灌(丛)木林地土壤呼吸及土壤理化性质,对干旱区灌(丛)木林地土壤呼吸与土壤因子及环境因子之间的相关性作了初步分析并得出二者沿流域的变化规律:(1)大气CO2浓度呈降低趋势,但不明显,土壤呼吸与大气相对湿度的变化趋势一致,沿流域降低,二者相关系数为0.97。在干旱区水分对土壤呼吸具有一定的影响;(2)相关性分析表明土壤碳酸钙与土壤呼吸间存在显著相关性,相关系数为0.93。有关干旱区土壤碳酸钙对土壤呼吸的作用机理有待于进一步深入研究。本文分析结果有助于人们更好的了解有关干旱区灌(丛)木林地的土壤呼吸,作为干旱区灌(丛)木林地土壤碳素研究的参考依据。

Analysis on Respiration of Soil in Scrublands and Its Affecting Factors in Arid Areas

In order to elucidate the variety of soil respiration in the oasis-desert ecotone,in this paper the values of respiration and physiochemical properties of soil in scrublands in the Sangong River Basin,an arid area in Xinjiang,China,are measured,and the correlations between the respiration of soil in scrublands and the soil factors and environmental factors are analyzed.The results are as follows:(1) Concentration of dioxide carbon in atmosphere near ground surface is in a slight decrease trend,the variety of the soil respiration accords with that of air relative humidity,the correlation coefficient is 0.97,and the soil respiration is affected by soil moisture content to some extent in arid areas;(2) There is a significant correlation between the soil respiration and the content of C_aCO_3 in soil,and the coefficient is 0.93.The action mechanism of C_aCO_3 on the soil respiration in arid areas needs to be further researched.