Data from: Long-term experimental warming alters community composition of ascomycetes in Alaskan moist and dry arctic tundra

Arctic tundra regions have been responding to global warming with visible changes in plant community composition, including expansion of shrubs and declines in lichens and bryophytes. Even though it is well-known that the majority of arctic plants are associated with their symbiotic fungi, how fungal community composition will be different with climate warming remains largely unknown. In this study, we addressed the effects of long-term (18 years) experimental warming on the community composition and taxonomic richness of soil ascomycetes in dry and moist tundra types. Using deep Ion Torrent sequencing we quantified how OTU assemblage and richness of different orders of Ascomycota changed in response to summer warming. Experimental warming significantly altered ascomycete communities with stronger responses observed in the moist tundra compared to dry tundra. The proportion of several lichenized and moss-associated fungi decreased with warming, while the proportion of several plant and insect pathogens and saprotrophic species was higher in the warming treatment. The observed alterations in both taxonomic and ecological groups of ascomycetes are discussed in relation to previously reported warming-induced shifts in arctic plant communities, including decline in lichens and bryophytes and increase in coverage and biomass of shrubs.

北极苔原区域已响应全球变暖，植物群落组成发生显著变化，具体表现为灌木扩张，地衣与苔藓植物（bryophytes）的丰度下降。尽管学界已证实多数北极植物与其共生真菌存在共生关系，但气候变暖将如何改变真菌群落组成，目前仍鲜有研究探明。本研究针对为期18年的长期实验增温处理，探究了其对干燥苔原与湿润苔原两种生境中土壤子囊真菌（ascomycetes）的群落组成及分类学丰富度的影响。本研究采用深度离子激流测序（Ion Torrent）技术，量化了子囊菌门（Ascomycota）不同目级类群的操作分类单元（OTU）集合与丰富度对夏季增温的响应变化。实验增温显著改变了子囊真菌群落结构，且相较于干燥苔原，湿润苔原的群落响应更为显著。若干地衣共生真菌与苔藓相关真菌的相对占比随增温处理出现下降，而若干植物病原菌、昆虫病原菌及腐生营养物种的相对占比在增温实验组中更高。本研究结合此前报道的变暖诱导的北极植物群落转变——包括地衣与苔藓植物丰度下降、灌木盖度及生物量提升——对子囊真菌分类群与生态类群的上述改变展开了讨论。