荒漠生态系统土壤呼吸速率对环境因子的响应

为探明环境因子与土壤碳释放之间的关系,利用LI-8100土壤碳通量自动测定仪监测塔里木河下游典型断面的荒漠河岸林群落土壤呼吸的变化动态,并同步观测植被盖度、地下水位、土壤特性及温度等相关因子的变化,分析其与土壤的关系。结果表明:1)在同一温度范围条件下,虽然土壤呼吸对温度变化有所响应,但温度不再是土壤呼吸作用的主要限制因子,根系和土壤微生物的生命活动很容易受到其他因素的影响和制约;2)监测区地下水对土壤呼吸速率存在一定的影响,地下水位越高土壤呼吸速率越小,地下水位越低土壤呼吸速率越大;3)植被盖度与地下水同时作用于土壤呼吸过程;4)在地下水的影响下土壤特性对土壤呼吸过程也存在影响。

Response of Soil Respiratory Rate to Environmental Factors in Desert Ecosystem

The variation dynamic condition of soil respiration in forest community along the river bank of the lower reaches of Tarim River in desert ecosystem was determined by LI-8100 Soil Carbon Flux Automatic Analyzer and the correlations between soil respiration rate and vegetation coverage, underground water level, soil properties, temperature were studied to discuss the correlations between environmental factors and soil carbon emission.Results: 1) Soil respiration has the effect on temperature under the same temperature range but soil temperature is not the main inhibiting factor on soil respiration.The life activity of root system and microorganism is influenced and inhibited easily.2) The underground water level has the certain effect on soil respiration rate.Soil respiration rate reduces with increase of underground water level and soil respiration rate increases with reduction of underground water level.3)The vegetation coverage and underground water level both have the effect on soil respiration process simultaneously.4) Soil property has the effect on soil respiration process under influence of underground water level also.