黄土高原生物结皮覆盖下表层土壤有机碳组分对模拟气候暖湿化的响应  

Responses of organic carbon fractions in biocrust-covered surface soil to simulated warming and wetting on the Loess Plateau,Northwest China

作　　者：冼海英 肖波 姚小萌[3] 窦韦强 XIAN Haiying;XIAO Bo;YAO Xiaomeng;DOU Weiqiang(College of Land Science and Technology,China Agricultural University/Key Laboratory of Arable Land Conservation in North China,Ministry of Agriculture and Rural Affairs,Beijing 100193,China;State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling 712100,Shaanxi,China;Hebei Key Laboratory of Environmental Change and Ecological Construction,College of Resources and Environmental Science,Hebei Normal University,Shijiazhuang 050024,China)

机构地区：[1]中国农业大学土地科学与技术学院/农业农村部华北耕地保育重点实验室,北京100193 [2]中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [3]河北师范大学资源与环境科学学院环境演变与生态建设实验室,石家庄050024

出　　处：《应用生态学报》2025年第1期132-140,共9页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金面上项目(42077010);中国科学院“西部之光”人才培养引进计划项目(2019)资助。

摘　　要：全球气候变化加剧可能会导致干旱半干旱区气温上升和降雨量增加。生物结皮作为干旱半干旱区重要的地表覆被物,其所覆盖土壤中有机碳组分与稳定性如何响应未来气候暖湿化尚不明确。本研究以黄土高原藓类生物结皮为对象,探究了土壤有机碳组分及其稳定性对持续两年增温(增加约3℃)、增温+增雨10%、增温+增雨30%和增温+增雨50%的响应。结果表明:1)与不增温增雨的对照相比,单独增温和增温增雨均显著提高了藓类生物结皮覆盖土壤表层总有机碳及其组分含量,但降低了土壤有机碳稳定性。增温和增温增雨处理使土壤总有机碳、活性有机碳(易氧化有机碳、可溶性有机碳和微生物生物量碳)和惰性有机碳含量分别平均增加了28%、51%和24%,同时使土壤有机碳活性指数平均提高了28%。与增温处理相比,增温增雨处理下土壤总有机碳、活性有机碳和惰性有机碳含量随增雨幅度的升高分别平均增加了25%、30%和22%,同时土壤有机碳活性指数平均提高了15%。2)模拟暖湿化气候条件下,土壤总有机碳、活性有机碳和惰性有机碳含量与生物结皮盖度、苔藓生物量和密度以及铵态氮和硝态氮含量呈显著正相关;年降雨量平均解释了土壤有机碳组分变化的88%。综上,气候暖湿化改变了生物结皮的碳转化策略,提高了土壤有机碳组分含量及其活性,但其活性增强导致稳定性下降。因此,未来暖湿气候加剧背景下,黄土高原地区藓类生物结皮覆盖土壤中有机碳含量可能会增加,土壤碳库的动态变化可能更剧烈。The intensification of global climate change may increase temperature and precipitation in drylands. Biocrust is one of the important surface covers in drylands. The responses of soil organic carbon(SOC) fractions and their stability in biocrusts-covered soil to climate warming and wetting remain unclear. We investigated the response of SOC fractions and stability under moss-dominated biocrusts in the Loess Plateau to two years warming(approximately 3 ℃ increase) crossed with 10%, 30% and 50% increases in precipitation. The results showed that: 1)The contents of SOC and its fractions in the surface layer covered by moss biocrusts were significantly increased by both warming and warming combined with wetting, whereas SOC stability was decreased. Both warming and warming combined with wetting increased the contents of SOC, labile organic carbon(LOC, including microbial biomass carbon, dissolved organic carbon and easily oxidized organic carbon) and recalcitrant organic carbon(ROC) by 28%, 51% and 24% on average, respectively. They also increased the labile index of organic carbon(LIC) by an average of 28%. In contrast to only warming, the treatments that combined warming and wetting resulted in average increases in SOC, LOC and ROC of 25%, 30% and 22%, together with a 15% rise in LIC. 2) There were significant and positive correlations between the contents of SOC, LOC and ROC and biocrust cover, moss biomass, moss density, and ammonium and nitrate contents under simulated warming and wetting. Furthermore, annual precipita-tion accounted for an average of 88% of the variation in SOC components. In conclusion, the warming and wetting climate changed the carbon conversion strategies of biocrusts, increased the content and activity of SOC components and decreased SOC stability. Therefore, in future intensified warming and wetting scenarios, SOC content in moss-dominated biocrust-covered soils in the Loess Plateau region may increase, with more pronounced dynamic changes in soil carbon pools.

关 键 词：气候变化 生物土壤结皮 碳循环 碳转化 黄土高原 

分 类 号：S153.6[农业科学—土壤学]