生物结皮演替对黄土高原水蚀风蚀交错区土壤氮素转化及微生物活性的促进效应  

Promoting effect of biological soil crusts succession on soil nitrogen transformation and microbial activity in water-wind erosion crisscross region of Loess Plateau

作　　者：焦冰洁 张丙昌 赵康 闫丽霞 武志芳 Bingjie Jiao;Bingchang Zhang;Kang Zhao;Lixia Yan;Zhifang Wu(School of Geographical Sciences/,Shanxi Normal University,Taiyuan 030000,China;School of Life Science,Shanxi Normal University,Taiyuan 030000,China;The First Senior High School of Funing,Funing 224400,Jiangsu,China)

机构地区：[1]山西师范大学,地理科学学院,山西太原030000 [2]山西师范大学,生命科学学院,山西太原030000 [3]阜宁第一高级中学,江苏阜宁224400

出　　处：《中国沙漠》2023年第4期191-199,共9页Journal of Desert Research

基　　金：国家自然科学基金项目(U2003214)。

摘　　要：以黄土高原风蚀水蚀交错区六道沟小流域的生物结皮为研究对象,探索了土壤氮素含量、氮转化相关酶活性及微生物数量对生物结皮演替的响应规律及其在不同土层上的变化特征。结果表明:生物结皮演替显著增加了结皮层的有机碳(SOC)和NO3--N含量(P<0.05);结皮演替后期阶段的总氮(TN)、NH4+-N含量也逐渐增加;除脲酶、亚硝酸还原酶外,结皮层中固氮酶活性、蛋白酶活性、硝酸还原酶活性均随结皮演替呈显著增加趋势(P<0.05);微生物量碳和氮(MBC、MBN)亦随生物结皮演替而呈显著升高趋势(P<0.05);细菌、真菌同样在结皮演替后期数量增加。生物结皮层的土壤养分、酶活性和微生物数量等多数指标显著高于结皮下层土壤;生物结皮下层土壤的SOC含量、硝酸还原酶活性显著高于裸地下层,但不同结皮类型的下层土壤之间无显著差异;苔藓结皮下层土壤的脲酶活性和MBN最高,显著高于藻结皮和裸地下层土壤。土壤碳氮含量、微生物量与氮转化相关酶活性之间多数具有显著的相关关系。在生物结皮演替过程中,土壤SOC的积累增加了微生物量与细菌、真菌数量,氮功能微生物提高了氮素含量和相关酶活性,在氮素积累和转化过程中发挥着关键作用,为植物的繁衍与生长提供了宝贵的养分,促进黄土高原水蚀风蚀区的水土保持与地表稳定。Biological soil crusts(BSCs)are widely developed and play critical ecological functions in water-wind erosion crisscross region on the Loess Plateau.In this paper,we analyze the response of soil nitrogen contents(SOC,TN,NH-N,NO-N),enzyme activities related with N,and microbial biomass to BSCs succession and their changing properties in different soil layers BSCs and deeper soil.The results indicated that BSCs succession significantly increase the contents of organic C and nitrate(NO-N).The TN,NH-N contents also gradually increased in the late stage of biological nodulation.Except urease and nitrite reductase,the activities of nitrogenase,nitrogenase,protease,nitrate reductase in BSCs showed a significant increase trend with BSCs succession(P<0.05).The microbial biomass C,N(MBC,MBN)also represented the same trend.Bacteria and fungi likewise increase in number later in the crusting succession.Most of the soil nutrient,enzyme activity and microorganism quantity in BSCs were significantly higher than those in 0-5 cm soil layer below BSCs(P<0.05).In 0-5 cm soil layer,the content of organic carbon and nitrate reductase activities in BSCs showed no significant differences among algal crusts,lichen crusts and moss crusts,but were significantly higher than those in the bare soil.Urease activity and microbial biomass N were the highest in 0-5 cm soil layer below moss crusts and significantly higher than in same soil layer under algal crust and bare soil.In the process of BSCs succession,the accumulation of soil organic carbon increase MBC,MBN and the number of bacteria and fungi.The N-related microorganism improve the content of nitrogen and enzyme activities related N in BSCs and play a key roles in N accumulation and transformation.They provide valuable nutrients for plant reproduction and growth,then promote soil and water conservation,and surface stability in water and wind erosion crisscross in the loess plateau.

关 键 词：水蚀风蚀交错区 生物结皮 土壤养分 微生物量 土壤酶活性 

分 类 号：Q948.1[生物学—植物学]