Natural Resources Institute Finland, Ounasjoentie 6, FI-96200 Rovaniemi, Finland.
Ecology and Genetics Research Unit, University of Oulu, Pentti Kaiteran katu 1, FI-90014 Oulu, Finland.
FEMS Microbiol Ecol. 2024 Mar 12;100(4). doi: 10.1093/femsec/fiae036.
Climate change is affecting winter snow conditions significantly in northern ecosystems but the effects of the changing conditions for soil microbial communities are not well-understood. We utilized naturally occurring differences in snow accumulation to understand how the wintertime subnivean conditions shape bacterial and fungal communities in dwarf shrub-dominated sub-Arctic Fennoscandian tundra sampled in mid-winter, early, and late growing season. Phospholipid fatty acid (PLFA) and quantitative PCR analyses indicated that fungal abundance was higher in windswept tundra heaths with low snow accumulation and lower nutrient availability. This was associated with clear differences in the microbial community structure throughout the season. Members of Clavaria spp. and Sebacinales were especially dominant in the windswept heaths. Bacterial biomass proxies were higher in the snow-accumulating tundra heaths in the late growing season but there were only minor differences in the biomass or community structure in winter. Bacterial communities were dominated by members of Alphaproteobacteria, Actinomycetota, and Acidobacteriota and were less affected by the snow conditions than the fungal communities. The results suggest that small-scale spatial patterns in snow accumulation leading to a mosaic of differing tundra heath vegetation shapes bacterial and fungal communities as well as soil carbon and nutrient availability.
气候变化显著影响了北方生态系统的冬季积雪条件，但土壤微生物群落变化条件的影响还没有被很好地理解。我们利用自然发生的积雪积累差异，了解冬季亚北极芬诺斯堪的亚矮灌丛主导冻原的土壤微生物群落如何在中冬季、早期和晚期生长季节形成。磷脂脂肪酸 (PLFA) 和定量 PCR 分析表明，在积雪少、养分供应低的风吹灌丛苔原中，真菌丰度更高。这与整个季节微生物群落结构的明显差异有关。Clavaria spp. 和 Sebacinales 的成员在风吹灌丛苔原中尤为占优势。在生长后期，积雪积累的冻原苔原中的细菌生物量指标较高，但在冬季，生物量或群落结构只有微小差异。细菌群落主要由 Alphaproteobacteria、Actinomycetota 和 Acidobacteriota 的成员组成，受雪况的影响小于真菌群落。研究结果表明，导致不同冻原苔原植被镶嵌的小规模空间尺度积雪积累模式会塑造细菌和真菌群落以及土壤碳和养分的可利用性。
