Data for: Warming increases negative interactions of a juvenile fescue and nearby plants in a tundra, moss facilitates mycorrhizae

In systems where low temperatures limit plant productivity, facilitative effects of surrounding vegetation on juvenile plants may outweigh effects of competition for resources, mainly through temperature buffering but also via increased availability of root mutualists such as mycorrhizal fungi. Climate warming could cause this balance between facilitation and competition to shift. We investigated how first-year plant performance, biomass allocation, and mycorrhizal colonization were affected by neighboring vegetation, both under ambient temperatures and under experimental warming. Juveniles of the grass species Festuca ovina (L., Poaceae) were planted into an alpine tundra ecosystem in central Norway, into one of four microsite types: a moss and lichen layer, other graminoids, both groups, or neither (bare soil). Half of the microsites experienced ambient conditions and half were located within open-top warming chambers. Warming increased shoot biomass of F. ovina, but only if planted i..., , , # Data for: Warming increases negative interactions of a juvenile fescue and nearby plants in a tundra, moss facilitates mycorrhizae

[https://doi.org/10.5061/dryad.qbzkh18tx](https://doi.org/10.5061/dryad.qbzkh18tx)

## Description of the data and file structure

This dataset contains all the data and software necessary to recreate the analyses and figures presented in our manuscript entitled \"Warming increases negative interactions of a juvenile fescue and nearby plants in a tundra, moss facilitates mycorrhizae\". In brief, in central Norway (The study site is located at 62.30553 °N, 9.65095 °E, at 1352 m a.s.l. on a west-facing slope in the Dovrefjell mountains of Norway), we planted individuals of the perennial grass *Festuca ovina* into four types of naturally occurring microsites (characterized by presence/absence of grass and moss-lichen complexes). Within each of these microsites, we implemented an experimental warming treatment using open-top chambers. Each microsite class recei...,