白芨滩地区不同生物土壤结皮类型对微生物群落结构和组成的影响

Effects of Different Biological Soil Crust Types on Microbial Community Structure and Composition in Baijitan,China

白芨滩国家级自然保护区及其周边植被恢复有利于改善区域生态环境,而植被恢复良好的区域内镶嵌分布着大面积藓结皮和藻结皮,其在防风固沙、改善荒漠生态系统地表土壤质量等方面发挥着重要作用。为深入了解该区域不同生物土壤结皮中微生物群落结构及其差异,选取藓结皮和藻结皮镶嵌分布的地表覆盖区设置取样点,分别对藓结皮和藻结皮进行细菌和真菌的Illumina MiSeq测序。结果表明,不同生物土壤结皮中细菌群落和真菌群落α多样性趋于一致,仅反映细菌群落丰富度的ACE和Chao指数在藓结皮中显著高于藻结皮。不同生物土壤结皮形成以微枝形杆菌属、红色杆菌属、地嗜皮菌属、芽球菌属、鞘氨醇单胞菌属、土壤红杆菌属、微红微球菌属、类诺卡氏菌属和苔藓杆菌属等为主要类群的细菌群落结构以及以赤霉菌属、Knufia、被孢霉属、石果衣属、链格孢属、Bahusakala、Phaeomycocentrospora、光黑壳属和Omphalina等属为主要已知类群的真菌群落结构。藓结皮中,红色杆菌属细菌相对丰度显著低于藻结皮,而苔藓杆菌属细菌相对丰度显著高于藻结皮。藓结皮中,Knufia、Bahusakala、Omphalina、Lamprospora、Vishniacozyma、Phoma、Entoloma和Trichoderma等属真菌相对丰度显著高于藻结皮;而藓结皮中,Powellomyces、Sporormiella、Thielavia、Iodophanus、Agaricus和Acrophialophora等属真菌相对丰度显著低于藻结皮。生物土壤结皮类型对细菌和真菌群落结构均产生显著影响,分别能够解释不同生物土壤结皮细菌和真菌群落结构差异的14%和8%。这些结果可为深入认识该区域不同生物土壤结皮在荒漠生态系统恢复过程中所具备的生态功能提供微生物多样性数据支撑。

Vegetation restoration on the Baijitan National Nature Reserve and in the surrounding areas promotes improvements in the regional ecological environment.A large area of mossy and algal biocrust with a mosaic structure is distributed within the vegetation restoration zone,and this plays an important role in blocking wind,fixing sand and improving the surface soil quality of this desert ecosystem.To fully understand the microbial community structure and differences in different biological soil crusts,sampling sites with a mosaic distribution of mossy and algal biocrust were selected,and the bacteria and fungi within the biocrust were sequenced using Illumina MiSeq technology.The results show that the α diversity of the bacterial and fungal communities in different biological soil crusts tended to be consistent.The Ace and Chao indices,which only reflected the richness of the bacterial community,were significantly higher in the moss biocrust than in the algal biocrust.The bacterial community was mainly composed of Microvirga,Rubrobacter,Geodermatophilus,Blastococcus,Sphingomonas,Solirubrobacter,Rubellimicrobium,Nocardioides and Bryobacter genera,while the fungal community mainly included Gibberella,Knufia,Mortierella,Endocarpon,Alternaria,Bahusakala,Phaeomycocentrospora,Preussia and Omphalina genera.The relative abundance of Rubrobacter in the mossy biocrust was significantly lower than in the algal biocrust,while the relative abundance of Bryobacter was significantly higher in the mossy biocrust than in the algal biocrust.The relative abundance of Knufia,Bahusakala,Omphalina,Lamprospora,Vishniacozyma,Phoma,Entoloma and Trichoderma genera in the mossy biocrust was significantly higher than in the algal biocrust,while the relative abundance of Powellomyces,Sporormiella,Thielavia,Iodophanus,Agaricus and Acrophialophora genera in the mossy biocrust was significantly lower than in the algal biocrust.Biological soil crust types have a significant impact on the bacterial and fungal community structure,and can explain 14% of the differences in the bacterial community structure and 8% of the differences in the fungal community structure.These results can provide microbial diversity data for an in-depth understanding of the ecological functions of different biological soil crusts in the process of desert ecosystem restoration.