内蒙古阿拉善西部荒漠土壤有机碳含量特征

Characterization of soil organic carbon content in western desert of Alagxa League of Inner Mongolia

对内蒙古阿拉善西部荒漠典型荒漠区和极旱荒漠区中14个优势植物群落的土壤有机碳含量及其空间分布特征进行了分析。结果表明,在水平分布上,依据显著性分析将植物群落间的土壤有机碳含量分为Ⅰ~Ⅳ级,Ⅰ级为柽柳群落和合头藜群落(平均有机碳含量3.62g/kg),Ⅱ级为盐爪爪群落、黄沙蒿群落和星毛短舌菊群落(平均有机碳含量2.38g/kg),Ⅲ级为珍珠群落和绵刺群落(平均有机碳含量1.66g/kg),Ⅳ级为白沙蒿群落、泡泡刺群落、梭梭群落、红砂群落、白刺群落、膜果麻黄群落和刺旋花群落(平均有机碳含量1.00g/kg);在垂直分布上,土壤有机碳含量与土层深度间呈曲线形相关或直线形相关,且群落间土壤有机碳含量皆随土层深度的增加而减少。

The objective of this study was to characterize the soil organic carbon content and its spatial distribution of 14 dominant plant communities in typical desert area and extremely dry desert area in western desert of Alagxa League of Inner Mongolia.The significance analysis results demonstrated that in the aspect of horizontal distribution,the soil organic carbon content among the varied plant communities were categorized into the followingⅠ-Ⅳ levels: the communities of Tamarix chinensis and Sympema regelii were determined as levelⅠwith average organic carbon content of 3.62 g/kg;the communities of Kalidium foliatum,Artemisia xanthochroa and Brachanthemum pulvinatum were included in level Ⅱ with average organic carbon content of 2.38 g/kg;the communities of Salsola passerine and Potaninia mongolica were classified in level Ⅲ with average organic carbon content of 1.66 g/kg;the communities of Artemisia sphaerocephala,Nitraria sphaerocarpa,Haloxylon ammodendron,Reaumuria soongorica,Nitraria tangutorum,Ephedra przewalskii and Convolvulus tragacanthoide were sorted in level Ⅳ with average organic carbon content of 1.00 g/kg.Furthermore,in the aspect of vertical distribution,there was a curve or linear correlation between soil organic carbon content and soil depth,and the soil organic carbon content were all decreased with the increase of soil depth among the observed plant communities.