Newsham Kevin K, Davey Marie L, Hopkins David W, Dennis Paul G
British Antarctic Survey, Natural Environment Research Council, Cambridge, United Kingdom.
Norwegian Institute for Nature Research, Trondheim, Norway.
Front Microbiol. 2021 Jan 26;11:615659. doi: 10.3389/fmicb.2020.615659. eCollection 2020.
We report a metabarcoding study documenting the fungal taxa in 29 barren fellfield soils sampled from along a 1,650 km transect encompassing almost the entire maritime Antarctic (60-72°S) and the environmental factors structuring the richness, relative abundance, and taxonomic composition of three guilds and growth forms. The richness of the lichenised fungal guild, which accounted for 19% of the total fungal community, was positively associated with mean annual surface air temperature (MASAT), with an increase of 1.7 operational taxonomic units (OTUs) of lichenised fungi per degree Celsius rise in air temperature. Soil Mn concentration, MASAT, C:N ratio, and pH value determined the taxonomic composition of the lichenised guild, and the relative abundance of the guild was best predicted by soil Mn concentration. There was a 3% decrease in the relative abundance of the saprotrophic fungal guild in the total community for each degree Celsius rise in air temperature, and the OTU richness of the guild, which accounted for 39% of the community, was negatively associated with Mn concentration. The taxonomic composition of the saprotrophic guild varied with MASAT, pH value, and Mn, NH -N, and SO concentrations. The richness of the yeast community, which comprised 3% of the total fungal community, was positively associated with soil K concentration, with its composition being determined by C:N ratio. In contrast with a similar study in the Arctic, the relative abundance and richness of lichenised fungi declined between 60°S and 69°S, with those of saprotrophic Agaricales also declining sharply in soils beyond 63°S. Basidiomycota, which accounted for 4% of reads, were much less frequent than in vegetated soils at lower latitudes, with the Ascomycota (70% of reads) being the dominant phylum. We conclude that the richness, relative abundance, and taxonomic composition of guilds and growth forms of maritime Antarctic soil fungi are influenced by air temperature and edaphic factors, with implications for the soils of the region as its climate changes during the 21st century.
我们报告了一项元条形码研究，该研究记录了从一条长达1650公里的样带沿线采集的29份贫瘠苔原土壤中的真菌分类群，该样带几乎覆盖了整个南极海洋区域（南纬60 - 72°），以及构建三个真菌类群和生长形式的丰富度、相对丰度和分类组成的环境因素。地衣化真菌类群的丰富度占真菌群落总数的19%，与年平均地表气温（MASAT）呈正相关，气温每升高1摄氏度，地衣化真菌的操作分类单元（OTU）增加1.7个。土壤锰浓度、MASAT、碳氮比和pH值决定了地衣化真菌类群的分类组成，该类群的相对丰度最好由土壤锰浓度预测。气温每升高1摄氏度，腐生真菌类群在总群落中的相对丰度下降3%，该类群的OTU丰富度占群落的39%，与锰浓度呈负相关。腐生真菌类群的分类组成随MASAT、pH值以及锰、铵态氮和硫酸根浓度而变化。酵母群落的丰富度占真菌群落总数的3%，与土壤钾浓度呈正相关，其组成由碳氮比决定。与北极的一项类似研究相比，地衣化真菌的相对丰度和丰富度在南纬60°至69°之间下降，腐生伞菌目真菌在南纬63°以南的土壤中也急剧下降。担子菌门占读数的4%，比低纬度植被土壤中的频率低得多，子囊菌门（占读数的70%）是优势门。我们得出结论，南极海洋土壤真菌类群和生长形式的丰富度、相对丰度和分类组成受气温和土壤因素影响，这对该地区在21世纪气候变化期间的土壤具有重要意义。
