[关键词]
[摘要]
为探究温带河口湿地原生芦苇群落和人工棉田群落的土壤碳通量特征及其与各环境因子的关系,利用Li-8100开路式土壤碳通量测量系统对黄河三角洲湿地棉田和芦苇两种植被覆盖下的土壤呼吸速率进行了监测,同时测定了土壤和大气的温度、湿度,分析了两种不同利用方式的土壤呼吸变化规律及相关影响因子。结果表明:棉花群落和芦苇群落样地的土壤呼吸速率日变化曲线均呈不对称的单峰形式,且变化趋势基本相同,在12:00-14:00达到峰值,在6:00-8:00到达谷值,棉田的土壤呼吸高于芦苇地,且平均呼吸速率表现为棉花群落(0.927μmol?m-2?s-1)高于芦苇群落(0.705μmol?m-2?s-1),这证明人为耕作会增加土壤碳通量的释放,导致碳排放量的增加。经相关性分析得出,土壤温度和大气湿度是影响棉花群落和芦苇群落土壤呼吸日变化的主要因素,其中前者对芦苇地影响更大,而后者对棉田的影响更大。
[Key word]
[Abstract]
To discuss the variations in Carbon Di-Oxide emission rate between reed and cotton fields of estuary wetland in temperate zone, we set an experiment to examine the differences of soil respiration rate between cotton community and reed community. The experiment was held in Autumn,10,6,2012. and experiment field lay in Yellow River Delt, the youngest wetland in temperate area. The soil respiration rate was measured by Li-8100 (produced by USA), the data of soil temperature and moisture were also collected by the instrument of Li-8100, atmospheric temperature and relative humidity were monitored synchronously. The results show that the daily changing curves of soil respiratory rate of both cotton community and reed community were asymmetric unimodal, the maximum rate appeared at 12:00-14:00, and the minimum rate took place at 6:00-8:00. However, the mean respiratory rate of the two communities showed great difference, the average respiratory rate of cotton community and reed community were 0.927 μmol?m-2?s-1 and 0.725μmol?m-2?s-1 respectively, this phenomena tells us that cultivated wetland can lead to the increase in carbon emission and contributes to the global warming. The correlation analysis discloses that soil temperature and atmospheric humidity were the main factors influencing soil respiration of the two communities. In detail, soil temperature was the primary environmental factor influencing soil respiration of reed community, and the atmospheric humidity influenced soil respiration of cotton community mainly. The experiment data can be used as the parameters of estuary wetland ecosystem carbon cycle.
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[基金项目]
国家科技支撑计划项目(2014BAC15B02),国家自然科学基金(40901276),山东省优秀中青年科学家科研奖励基金(2011BSB01256);聊城大学大学生创新项目(SF2013136)