不同荒漠生态系统下有机碳和微生物碳的分布特征

基于新疆古尔班通古特沙漠南缘原始盐生旱生荒漠的3种建群灌木琵琶柴(Reaumuria soongori-ca)、多枝柽柳(Tamarix ramosissima)和梭梭(Haloxylon ammodendron)生态系统下土壤剖面实测数据,分析了土壤有机碳(SOC)和土壤微生物量碳(Mc)的垂直分布特征及其与土壤理化因子的关系。结果表明:3个生态系统类型之间土壤剖面SOC分布状况和含量不存在显著差别,但每个生态系统土壤剖面土层之间存在显著差别。各生态系统土壤上层均存在着一定厚度的SOC富集层,中部(10～30cm)SOC含量迅速下降,下部有机碳含量低而稳定。Mc分布与含量与SOC存在相似的规律。Mc对90cm以上的土壤碳循环起着重要的作用,而对深层次的碳库影响不大,不会对全球变化做出响应,但意义更重要,它们可以更长期保留于土壤中而不释放回大气圈。

Distribution characteristics of soil organic carbon and microbio biomass carbon in different desert ecosystems

The soil organic carbon(SOC),soil microbial biomass carbon(Mc) and their relationship of the following soils were investigated to assess the impacts of location and soil depth on the contents and to cumulate the first dates to comprehend the soil C in the southern boundary of the Garbantunggut desert.The result showed that the contents of SOC and Mc are not significant different among different vegetation types,but in the same vegetation type there are significant different among different layers.In the same location,the contents of SOC and Mc in the profiles decrease remarkably within 10-30cm,decreased slightly within 30-500cm.Mc is significantly related with SOC(P<0.01).Mc between 0-90cm plays an important role in soil carbon cycle,and to deep carbon library the impact is not big,but it has more important significance,they can be retained in soil in more long-term and not be released back into the atmosphere.