摘要
生物结皮是干旱区生态系统光合固碳的重要贡献者,固碳功能菌是生物结皮碳固定过程中的关键功能群,而毛乌素沙地生物结皮有关固碳功能菌群落多样性的研究未见详细报道。通过qPCR和高通量测序,研究了毛乌素沙地固碳功能菌基因丰度、群落多样性在生物结皮发育过程中的演变规律及其关键环境因子。结果表明,form IAB、IC和ID的基因丰度均随生物结皮发育呈升高趋势,在地衣结皮最高,在藓结皮又明显降低;form IAB的Chao1和form IC的Shannon指数随生物结皮演替呈显著上升趋势,而form IC和ID的Chao1则在藻结皮达到峰值。物种组成上,IAB型固碳功能菌以蓝藻门的颤藻目占优势,其相对丰度在藻结皮最高,随生物结皮演替逐渐降低;IC型固碳功能菌在裸沙中以土壤红杆菌目为主,而在三种生物结皮中以生丝微菌目、亚硝化单胞菌目和红螺菌目占优势;ID型固碳菌则以硅藻门的舟形藻目占优势,其丰度在裸沙中最高。IAB和IC型固碳功能菌群落结构在藻结皮和地衣结皮类似,而与裸沙和藓结皮差异显著,裸沙与藓结皮亦具显著差异。生物结皮演替过程中生物类群和土壤理化特征的改变为固碳功能菌提供了不同的生态位,土壤总有机碳、全氮、铵态氮、全磷、速效磷和pH对固碳功能菌群落进行综合调控,通过对固碳功能菌的筛选作用,最终改变固碳功能菌群落组成和结构。为深入理解荒漠生态系统生物结皮的光合固碳功能的微生物学机制提供了理论支撑。
Biological soil crusts(BSCs)are key contributor of carbon sequestration of arid land ecosystem.Carbon-fixing microbes are the critical functional groups in the carbon sequestration in biological soil crusts.However,the detailed research on carbon-fixing microbial diversity of BSCs in Mu Us Sandy Land was not reported.To explore the variation of the abundance and community diversity of autotrophs in the succession of biological soil crusts,qPCR and Micseq sequencing were performed for the samples from Mu Us Sandy Land.The key environmental factors driving carbon-fixing microbial community were also explored.The results indicated that the abundance of form IAB,IC and ID gene increased with the development of BSCs and reached the highest in lichen crusts,then decreased clearly in moss crusts.Chao1 of form IAB and Shannon index of form IC showed the increasing trends with the succession of BSCs,whereas Chao1 of form IC and ID reached the highest in algal crusts.In terms of species composition,IAB-type autotrophic microbes were dominated by Oscillatoriales of Cyanobacteria,their relative abundance reached the highest in algal crusts and gradually decreased with the succession of BSCs.In the bare sand,IC type autotrophic microbes were dominated by Solirubrobacterales,Hyphomicrobiales,Nitrosomonadales and Rhodospirillales were dominated in BSCs.Naviculales of Bacillariophyta dominated the ID type microbes,and their abundance reached the highest in bare sand.The community structure of IAB and IC type autotrophic microbes were similar in algal crusts and lichen crusts,but significantly different from that in bare sand and moss crusts,which also had significant differences.The variations of biological groups and soil physicochemical properties provided different microhabitats(niches)for autotrophs.The total organic carbon,total nitrogen,ammonium nitrogen,total phosphorus,available phosphorus,and pH regulated autotrophic microbial communities comprehensively.Through the screening of carbon-fixing microbes,the community comp
作者
李凯凯
张丙昌
赵康
张雅丽
刘燕晋
LI Kaikai;ZHANG Bingchang;ZHAO Kang;ZHANG Yali;LIU Yanjin(School of Geographical Science,Shanxi Normal University,Taiyuan 030031,China;School of Biological Science,Shanxi Normal University,Taiyuan 030031,China;Research Center of Ecological Environment in the Middle Reaches of the Yellow River,Shanxi Normal University,Taiyuan 030031,China)
出处
《生态学报》
CAS
CSCD
北大核心
2024年第3期1177-1190,共14页
Acta Ecologica Sinica
基金
国家自然科学基金(42271067,U2003214)。
关键词
生物结皮
固碳功能菌
群落多样性
环境因素
毛乌素沙地
biological soil crusts
carbon-fixing microbes
community diversity
environmental factors
Mu Us Sandy Land
