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作 者 ：赵哈林,李玉强,周瑞莲

期 刊 ：生态学报 2010年 30卷 8期 页码：1972~1980

关键词：沙漠化；科尔沁沙地；土壤呼吸；环境因素；相互关系；

Keywords:desertification, Horqin Sand Land, soil respiration, environment factor, correlation,

摘 要 ：为了了解沙漠化过程中土壤呼吸速率变化及其对环境因素变化的响应，于2005年在科尔沁沙地研究了固定、半固定和流动沙地的土壤呼吸日变化和生长季动态及其与环境变化的关系，得出以下结论：(1) 3种沙地土壤呼吸日变化在春季和秋季呈单峰曲线，夏季呈多峰曲线；(2) 3种沙地土壤呼吸速率从春季到秋季的季节动态均呈双峰曲线，峰值分别出现在6月下旬和8月下旬；(3) 固定和半固定沙地的土壤呼吸的日变化幅度明显大于流动沙地，季节变化幅度也是固定沙地＞半固定沙地＞流动沙地；(4) 随着沙漠化的发展，土壤呼吸平均速率明显下降，生长季平均土壤呼吸速率从固定沙地的2.32μmol CO2/(m2?s)降为半固定的1.65μmol CO2/(m2?s)和流动沙地的1.06μmol CO2/(m2?s)；(5) 3种沙地土壤呼吸速率日变化均与土壤温度呈正相关，与空气湿度呈负相关，在季节尺度上3种沙地土壤呼吸速率与土壤温度、土壤水分和大气湿度均呈正相关，但只有固定沙地的相关性达到了显著水平；(6)沙漠化过程中，虽然土壤温度、土壤有机碳含量和植物根系碳含量都是导致沙地土壤呼吸发生改变的重要因子，但制约其变化的关键因子还是土壤水分和空气湿度。

Abstract:Soil respiration impacts carbon sequestration rates and atmospheric carbon dioxide levels. Daily dynamics and seasonal dynamics in soil respiration rate in three types of fixed, semi\|fixed and mobile sand land were measured in 2005 to understand soil respiration properties and its relation with environmental factors in land desertification processes of Horqin Sand Land. The results showed that (1) daily fluctuations in soil respiration presented a single peak curve during spring and autumn and a double peak curve during summer in the three sand lands; (2) seasonal dynamics in soil respiration presented a double peak curve in all the three sand lands, with peak values occurring during the last ten\|days of June and August; (3) the daily range of soil respiration rate was significantly greater in fixed and semi\|fixed sandy lands than in mobile sandy land, and the seasonal range of soil respiration was fixed sandy land ＞semi\|fixed sandy land ＞ mobile sandy land; (4) soil respiration rate decreased significantly with increasing desertification, and the average rate of soil respiration in a growing season decreased form 2.32 mol CO2/(m2?s) in fixed sand land to 1.65 mol CO2/(m2?s) in semi\|fixed sand land and 1.06 mol CO2/(m2?s) in mobile sand land; (5) in all of the three sand lands, daily change in soil respiration had a positive correlation with soil temperature, and a negative correlation with air humidity; seasonal change in soil respiration had positive correlation with air humid, soil temperature and moisture, but the correlation was statistically significant only in the fixed sand land; (6) although changes in soil temperature, organic carbon and plant root carbon content were important factors affecting the soil respiration rate in land desertification processes, the primary factors dominating soil respiration were air humidity and soil moisture.

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