Data from: Warming-induced effects on microbial communities and nitrogen cycling capacity in tundra litter

Abstract Climate warming is changing tundra vegetation in the Arctic, with implications for plant litter properties. To address potential warming effects, we characterized the responses of bacterial and fungal communities and their genetically encoded capacity for inorganic nitrogen-transformations in the litter layer, as well as 15N natural abundance in the underlying soil layer as an integrated measure of nitrogen processes in the soil, in 16 long-term alpine and Arctic tundra warming experiments distributed across 12 circumpolar locations. While local conditions primarily shaped microbial communities, warming indirectly affected microbial nitrogen-cycling potentials through changes in herb dominance and litter mass, resulting in enhanced links between litter nitrogen cycling potentials and δ¹⁵N in the underlying soil. Our results suggest that warming-driven vegetation changes may intensify nitrogen-cycling with possible positive feedback on plant growth and ecosystem respiration across the tundra biome. The data includes 1) Sample metadata, including site information, and litter sample measurements of abiotic properties, abundance of nitrogen cycling genes, and abundance and composition of bacterial and fungal communities (Data Table 1, including "README"), 2) and Plant community data in each sampled plot or OTC at the sites (Data Table 2, including "README"). The 16S rRNA gene and ITS2 sequences of prokaryotic and fungal communities, respectively, are deposited at the NCBI database under the BioProject PRJNA760312 (https://www.ncbi.nlm.nih.gov/bioproject/).