荒漠草原区不同植被恢复模式土壤微生物菌落分布特征及其与土壤理化性质的相关性

Distribution Characteristics of Soil Microbial Communities of Different Vegetation Restoration Models and Their Correlation with Soil Physical and Chemical Properties in Desert Steppe

研究土壤微生物菌落变化对土壤肥力的影响,对荒漠草原区草地的恢复管理具有重要的意义。本文以宁夏典型荒漠草原区的天然草地为对照,以平茬人工柠条林地、人工柠条林地、天然柠条林地为研究对象,采用稀释平板法估算各样地0~5,5~10,10~20,20~40 cm土层中微生物菌落数量,并测定对应土层的土壤理化性质及6种可溶性氮组分。通过分析样地内土壤微生物菌落数量变化特征及其与土壤理化性质的相关性可知:人工植被恢复加速土壤微生物菌落结构变化;人工柠条林地下土壤微生物群落数量较多、土壤结构及肥力较好;平茬措施可增加人工柠条林地微生物菌落数量,但微生物菌落总数仍低于未平茬前。综上所述,人工种植柠条更有利于荒漠草原区植被恢复。

It is of great significance for the restoration and management of grassland in desert steppe to study the effects of microbial colony changes on soil fertility.In this study,a typical desert steppe in Ningxia was selected as research area,with the natural grassland(NG)as control and pruned artificial Caragana Intermedia(PACI),artificial Caragana Intermedia(ACI)and natural Caragana Intermedia(NCI)as research objects.Soil from different soil layers were collected to estimate the amount of microbial community in various soil layers of 0~5,5~10,10~20 and 20~40 cm by the dilution plate method.Soil physical and chemical properties and 6 soluble organic nitrogen components of the corresponding soil layer were measured at the same time.The quantity variation characteristics of soil microbial communities in different sample plots and their correlation between soil physical and chemical properties were analyzed.The results showed that:the restoration process of artificial vegetation might accelerate the optimization of soil microbial colony structures.The number of microbial colonies of artificial C.intermedia forest was more and its soil microbial colony structures and fertility were better.Pruning could increase the umber of microbial colonies in artificial C.Intermedia forest,but it was still lower than that before pruned.In conclusion,planting C.Intermedia was more conducive to vegetation restoration in desert steppe.