不同土地利用方式对土壤惰性碳的影响  

Effects of different land use methods on inert soil carbon

作　　者：左超 罗彩云[1,2] 赵亮 赵新全[1,2] 常小峰[4] 潘思辰[1,2,3] ZUO Chao;LUO Cai-yun;ZHAO Liang;ZHAO Xin-quan;CHANG Xiao-feng;PAN Si-chen(Northwest Institute of Plateau Biology,Chinese Academy of Sciences,Xinin,810008,China;Institute of Sanjiangyuan National Park,Chinese Academy of Sciences,Xining 810008,China;University of Chinese Academy of Sciences,Beijing 100049,China;Institute of Soil and Water Conservation,Northwest A&F University,Yangling 712100,China)

机构地区：[1]中国科学院西北高原生物研究所,青海西宁810008 [2]中国科学院三江源国家公园研究院,青海西宁810008 [3]中国科学院大学,北京100049 [4]西北农林科技大学水土保持研究所,陕西杨凌712100

出　　处：《草原与草坪》2024年第2期96-105,共10页Grassland and Turf

基　　金：第二次青藏高原综合科学考察研究项目(2019QZKK 040104):祁连山国家公园开放课题(GKQ 2019-01)。

摘　　要：【目的】研究不同土地利用方式对草地土壤惰性碳的影响,对于客观认识草地在减少大气CO_(2)排放中的作用,制定草地碳增汇策略,合理利用草地资源具有重要意义。【方法】在中国科学院海北高寒草甸生态系统研究站3种不同利用方式土地(冬季自由放牧—冬牧、围封禁牧—禁牧、开垦播种燕麦—燕麦),采用梅花形5点采样法采集野外样品,结合室内酸水解等分析方法,对0~30 cm土层的土壤总有机碳和惰性碳进行分层研究。【结果】1)0~10 cm土层土壤有机碳含量以冬牧最高(95.15 g/kg),禁牧次之(70.56 g/kg),开垦播种燕麦最小(54.44 g/kg)。冬牧土壤惰性碳含量比禁牧高27.77%,冬牧比燕麦高32.54%。2)与冬牧相比,禁牧16年土壤0~10 cm土层有机碳下降了25.84%,开垦30年0~10 cm土层土壤有机碳下降了42.79%。禁牧16年土壤0~30 cm土层有机碳下降了10.89%,开垦30年0~30 cm土层土壤有机碳下降了9.48%。0~30 cm土层惰性碳平均含量冬牧比禁牧高22.67%,冬牧比燕麦高3.60%;与开垦相比,禁牧使惰性碳降低了19.78%。3)不同土地利用方式土壤理化性质与土壤碳库组成存在显著相关,土壤理化性质的改变是引起不同草地类型土壤碳库组成变化的重要原因。【结论】禁牧后土壤惰性碳含量降低的幅度大于开垦,冬牧有利于土壤惰性碳的积累;健康草地禁牧之后降低了土壤惰性碳的含量,减弱了土壤有机碳的稳定性。不同土地利用方式主要通过影响土壤理化性质及养分含量影响土壤有机碳和惰性碳含量。因此,通过改善放牧管理,可以维持或进一步增加有机碳存储以及土壤有机碳的稳定性,健康草地禁牧不利于土壤有机碳的积累。【Objective】Investigating the effects of different land uses on soil inert carbon in grassland is of great significance for objectively understanding the role of grassland in mitigating atmospheric carbon dioxide emissions,de⁃veloping strategies for carbon sequestration in grassland,and rational utilization of grassland resources.【Method】The total organic carbon and inert carbon of soil at Haibei Alpine Meadow Ecosystem Research Station of the Chi⁃nese Academy of Sciences were studied under three different land use methods(i.e.,free grazing in winter(winter grazing),grazing exclosure(grazing exclosure),and cultivated annual oats(oats)).【Result】1)Soil organic carbon content in the 0~10 cm soil layer was the highest under winter grazing(95.15 g/kg),followed by grazing exclosure(70.56 g/kg),and cultivated annual oats(54.44 g/kg),The content of soil inert carbon under winter grazing was 27.77%higher than that under grazing exclosure,and 32.54%higher than that under cultivated annual oats.2)Com⁃pared with winter grazing,soil organic carbon in the 0~10 cm layer decreased by 25.84%after 16 years of grazing ex⁃closure,and soil organic carbon in the 0~10 cm layer decreased by 42.79%after 30 years of cultivation,Compared to free grazing,the organic carbon in the 0~30 cm soil layer decreased by 10.89%after 16 years of grazing exclosure,and by 9.48%in the 0~30 cm soil layer after 30 years of cultivation,The average inert carbon content in the 0~30 cm soil layer was 22.67%higher under winter grazing than under grazing exclosure,and 3.60%higher under winter grazing than under annual oats,Compared with cultivation,grazing exclosure reduced the inert carbon by 19.78%.3)There was a significant correlation between soil physical and chemical properties and soil carbon pool composition un⁃der different land use methods,and the change in soil physical and chemical properties was an important reason for the change in soil carbon pool composition under different grassland use methods.【Conclusion】The decrease of

关 键 词：高寒草甸 不同土地利用方式 土壤有机碳 惰性碳 

分 类 号：S812.2[农业科学—草业科学]