生态学报2024，Vol.44Issue(15)：6630-6641,12.DOI:10.20103/j.stxb.202311092431
荒漠草原灌丛转变土壤有机碳矿化及其对降水梯度的响应
Soil organic carbon mineralization and its response to precipitation gradients during anthropogenic shrub encroachment in desert steppe
摘要
Abstract
To explore the impact of the anthropogenic transition from grassland to shrubland on soil organic carbon stability,a nearly 40 years typical grassland-shrubland mosaic(desert grassland,grassland edge,shrubland edge,shrubland)was selected to investigate soil organic carbon mineralization and its response characteristics of the precipitation(+40％,+20％,CK,-20％,-40％)by field in-situ observations combined with indoor incubation in the transition process.The main results were that soil organic carbon,total nitrogen and total phosphorus contents were significantly reduced and the cumulative soil organic carbon mineralization,the mineralization rate of soil organic carbon,carbon mineralization,and microbial metabolic entropy all showed an increasing trend with the transition process.It increased by 26.6％,27％,25.8％,and 26.8％in shrubland compared to desert grassland.The potentially mineralized carbon increased with transition fluctuations and was significantly higher in shrubland than in desert grassland by 31.55％.Under different precipitation gradients,the cumulative soil organic carbon mineralization in each transition site tended to increase with incubation time,and the mineralization rate of soil organic carbon tended to decrease.However,soil organic carbon mineralization was higher in shrubland and shrubland edge than in desert grassland and grassland edge.Soil organic carbon mineralization in shrubland and its edge was more sensitive and cheerful in response to reduced precipitation.In a conclusion,microbial mineralization of soil organic carbon was accelerated,and its capability of responding to drought was enhanced during these vegetation shifts.The results suggested that the transition process enhanced the microbial mineralization of soil organic carbon and its capacity to cope with drought,a capacity that perhaps came at the cost of higher microbial metabolic entropy and CO2 fluxes.关键词
荒漠草原/人为灌丛化/土壤碳矿化/降水梯度Key words
desert steppe/anthropogenic shrub encroachment/soil carbon mineralization/precipitation gradient引用本文复制引用
赵晓钰,陈彦硕,李志刚,王红梅,张振杰,李志丽,苏荣霞,赵亚楠..荒漠草原灌丛转变土壤有机碳矿化及其对降水梯度的响应[J].生态学报,2024,44(15):6630-6641,12.基金项目
国家自然科学基金项目(32260348,31860677) （32260348,31860677）
宁夏高等学校一流学科建设项目(NXYLXK2017A01) （NXYLXK2017A01）
