东平湖湖滨带不同植被类型下春季土壤CO_2通量研究

The Research on Carbon Dioxide Flux of the Three Communities in the Dongpinghu Riparian Zone

为了准确揭示湖滨带不同植被类型的土壤呼吸差异,并为湿地生态系统碳收支研究提供基础理论依据,采用LI-8100A开路式土壤碳通量测量系统,测定东平湖湖滨带3种典型植被类型(香蒲、芦苇、人工杨树林)的春季土壤CO2通量特征。结果表明:(1)3种植物群落中,人工杨树林的土壤有机质明显要高于其他2个原生湿地土壤。(2)3种植物群落的土壤CO2释放速率日变化趋势都均为单峰曲线;土壤碳通量速率最高值在12:00—14:00,最低值出现在6:00。以人为扰动过的土壤,即杨树林群落土壤呼吸速率最大,日平均值达到2.26μmol/(m2.s)。(3)土壤CO2释放速率与近地面大气温度的相关性要高于与土壤温度相关性。分析表明,同一气候区相同环境因子对不同植物群落土壤呼吸的影响作用不同,且因其自身具有明显的日变化,从而导致对土壤呼吸的调控作用也具有明显的日变化模式。

In order to accurately explore the differences of different vegetation types in lake riparian zone, and to provide a theoretical basis for research on wetlands ecosystem balance of carbon budget, daily variations of soil carbon flux of the three communities （Cattails, Phragmites and Artificial Poplat） in the Dongpinghu riparian zone were measured continuously in the spring of 2011 using LI-8100 automated soil C02 flux system. Environmental factors were also measured during the sampling periods. The results showed： （1） the soil organic matter of the artificial poplars was higher than the other two primary wetland soil. （2） The diurnal curves of soil respiration rate under the three communities had a simple peak value correlated well with atmosphere temperature generally with its maximum during 12：00-14：00 and minimum during 6：00. （3） Exponential models were used to describe the relationships between soil respiration rate and air temperature above ground, soil temperature, and the correlation between soil respiration rate and air temperature above ground was higher than that between soil respiration rate and soil temperature for the three communities. The environmental effects on soil respiration differed among plant community types. It was concluded that environmental changes would alter the daily soil respiration patterns for three plant communities.