封育对蒿类荒漠草地土壤微生物碳源利用特征的影响OA北大核心

This study was conducted in Hutubi and Manas Counties of Changji Hui Autonomous Prefecture in Xinjiang Uygur Autonomous Region,and investigated how soil microbial carbon source utilization patterns in sagebrush desert grassland changed in response to fencing enclosure.Field investigation and laboratory analyses were combined to measure and analyze the characteristics of soil microbial carbon source utilization both inside and outside the enclosure.Factors driving responses were examined based on vegetation characteristics and physicochemical properties of the soil.The results showed:1)After fencing enclosure,the aboveground biomass(AGB)and litter biomass(LB)of sagebrush desert grassland were significantly increased by 142.53%-250.05% and 135.68%-259.84% (P<0.05),respectively.The contents of soil organic carbon(SOC),total nitrogen(TN)and total phosphorus(TP)in 0-10 cm and 30-50 cm soil layers were increased by 4.88%-35.33%,10.48%-46.58% and 4.48%-21.88%,respectively,and the contents of total nitrogen and total phosphorus also showed significant changes(P<0.05).2)The utilization by soil microbial communities of six categories of carbon source increased significantly after enclosure,and the behavior of surface and deeper soil layers was consistent(P>0.05).3)After enclosure,the McIntosh index and Shannon-Wiener index increased by 14.72%-47.01% and 36.29%-74.76%,respectively,while the Simpson index decreased by 1.09%-7.53% (P>0.05),except in the 0-10 cm soil horizon in Hutubi County.Enclosure improved the microbial diversity of sagebrush desert grassland.4)Through redundancy analysis,it was found that the main driving factors of microbial carbon source in the 0-10 cm soil layer were SOC and litter biomass,while the driving factors in the 30-50 cm soil layer were soil TP and aboveground biomass.In conclusion,the enclosure by fencing in sagebrush desert grassland was found to enhance the metabolic activity of soil microorganisms,thereby fostering nutrient cycling and transformation within the ecosystem,specifically in terms of SOC,TN and TP.Furthermore,this practice led to an improvement in microbial diversity,ultimately promoting the restoration of degraded grassland and enhancing the overall health and resilience of the sagebrush desert grassland ecosystem.