艾比湖湿地土壤有机碳及储量空间分布特征

土壤碳储量的研究是全球碳循环研究的热点,土壤碳库的变化对全球气候变暖、维护生态平衡都有着重要的意义。新疆的艾比湖湿地是干旱区典型的盐湖湿地,为探明该湿地有机碳特性及储量,选择艾比湖湿地1m深度的土壤作为研究对象,测试有机碳含量后,对艾比湖湿地土壤有机碳特性进行分析并分层定量测算有机碳储量,结果显示:(1)艾比湖湿地土壤有机碳整体偏低,随土层加深,含量依次递减的规律比较显著。湿地7种不同植被覆盖类型的土壤有机碳含量垂直空间变异性差异明显,其中荒漠河岸林、盐化草甸、小乔木荒漠大多属于强变异,而其它植被覆盖的土壤类型多属于中等变异。(2)艾比湖湿地7种不同植被类型土壤有机碳含量在相同土层的分布特征为:有机碳集中分布在浅表层(0—20 cm),从40 cm以下变幅缓慢,分布较为均匀。不同植被类型土壤有机碳在不同土层的分配比例差异比较明显,但表层(0—20 cm)大多占到30%以上。(3)艾比湖湿地土壤有机碳储量排序依次为小乔木荒漠盐化草甸干涸湖底灌木荒漠盐生灌丛荒漠河岸林寒湿性针叶林。湿地有机碳蓄积总量为7086862.83 kgC。上述研究结果可为新疆干旱区湿地生态系统恢复、保护与科学管理提供科技支撑。

The characteristics and storage of soil organic carbon in the Ebinur lake wetland

Wetlands are an integral part of the environment, and have received tremendous scientific attention, especially in the arid zone. This research plays a very important role in our understanding of the sustainable development of an ecosystem. In this study, the Ebinur Lake wetland in Xinjiang was chosen as the study area, a typical arid area in China. Field investigation, analytical chemistry, and geostatistics methods were employed to ascertain the regularity of the differentiation of the organic carbon and related components of the soil. Their formation mechanisms were discussed, and a survey of organic carbon and total nitrogen was conducted. This study not only greatly enriches theoretical research on wetlands in arid areas, but also reveals sequestration mechanisms and the carbon sequestration potential of wetland ecosystems. In addition, it furthers our understanding of the regulator function of wetlands, evaluates the potential environmental impacts of ecosystems, and provides a practical reference for the rational utilization of these ecosystems and the coordination of the relationship between environmental protection and the sustainable development of the regional economy. The main conclusions are as follows:(1) the soil organic carbon content is low, and decreases as soil layer depth increases. The analysis of the nutrient variation coefficient of the soil organic carbon shows that desert riparian forest, salt meadow, and small trees in the desert exhibited strong variability, whereas the others exhibited medium variation; (2) the distribution of the soil organic carbon from seven vegetation types shows that organic carbon was concentrated 0-20 cm below the surface. The distribution is more uniform in the soil layer 40-100 cm deep. The allocation ratio of soil organic carbon in differs among vegetation types; however, the surface layer (0-20 cm) accounted for more than 30%. Finally, (3)the organic carbon accumulation in the Ebinur Lake wetland by landcover type is as follows:Microphanerophytes desert > saline meadow > dry lakebed > desert shrub > halophyte shrub > desert riparian forest > alpine coniferous forest. The total organic carbon accumulation of the soil is 7086862.83 kgC.