Herbivory modifies the role of spatial processes in a grassland plant metacommunity

Trophic interactions can strongly influence metacommunity dynamics and patterns of biodiversity in spatially heterogeneous environments. Herbivory is predicted to facilitate plant species coexistence on small scales by reducing extinctions and promoting colonisations, but could lead to a reduction in the size of the regional species pool and homogenization at larger scales. We examined how mammalian herbivory interacts with habitat size and connectivity to affect plant diversity in a natural grassland metacommunity. We found that herbivory increased plant diversity across scales of measurement. In addition, herbivory reversed the diversity-area relationship such that there was a positive diversity-area relationship in grazed grasslands, but a negative relationship in ungrazed grasslands. Connectivity exhibited a unimodal relationship with diversity but did not interact with herbivory. Our results demonstrate that herbivores can promote plant coexistence across scales and highlight the i..., , # Herbivory modifies the role of spatial processes in a grassland plant metacommunity

Dryad DOI: https://doi.org/10.5061/dryad.2bvq83c2p

This file describes the variables in the datasets that accompany:\
Lena Huovinen, Marjo Saastamoinen, Jonathan M. Chase, Anna-Liisa Laine, Aleksi Räsänen and Anu Eskelinen\
Herbivory modifies the role of spatial processes in a grassland plant metacommunity.\
Ecology Letters.

dataset: vegetation_trait_data_aland.csv\
Variable Description:\
shannon: Shannon diversity H = - Σipilog1pi, where pi is the proportional abundance of species (Hurlbert 1971)\
evenness: Evenness = H/log(richness) (Pielou 1966)\
richness: species richness as the number of vascular plant species in each 1 m2 plot\
patch_nr: grassland patch identifier\
plot: plot replicate nr in each patch\
herbivory: grazed, ungrazed\
connect: Connectivity = Σ j≠i, di,j ≤r Aj * (r-di,j), where r = maximum dispersal distance, here defined as 1 km, di,j = the distance between sampled focal patch i ...,