DOI: 10.5061/dryad.2bvq83c2p
title: Herbivory modifies the role of spatial processes in a grassland plant metacommunity

description: 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
 interplay between habitat area and trophic interactions in facilitating
 plant biodiversity in grassland metacommunities.
description: # 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 and adjacent patch j. Aj equals the area of the adjacent patch.\
 near_dist: distance calculated from edge to edge of two adjacent patches,
 (m)\ area: patch area (m2)\ dispersal_distance: CWM dispersal potential,
 which is calculated as the relative abundance of the species (% cover)
 multiplied by the species’ dispersal potential (Lososova et al. 2023) and
 summed across species.\ SLA: CWM of SLA (cm2 g-1), which is calculated as
 the relative abundance of the species (% cover) multiplied by the species´
 SLA and summed across species.\ tannin: CWM of foliar condensed tannin (mg
 g-1), which is calculated as the relative abundance of the species (%
 cover) multiplied by the species´ tannin and summed across species.\
 height: CWM of plant height (cm), which is calculated as the relative
 abundance of the species (% cover) multiplied by the species´ height and
 summed across species.\ wue: CWM of water use efficiency (WUE, proportion
 of the isotopes 237 13C/12C compared to the VPDB standard), which is
 calculated as the relative abundance of the species (% cover) multiplied
 by the species´ WUE and summed across species.\ cn: CWM of C:N (from C,
 N%), which is calculated as the relative abundance of the species (%
 cover) multiplied by the species´ C:N and summed across species. dataset:
 whole_patch_vegetation_aland.csv\ Variable Description\ patch_nr:
 grassland patch identifier\ richness: whole patch richness, the number of
 vascular plant species summed across the plots and transects within each
 patch\ herbivory: grazed, ungrazed\ area: patch area (m2)\ connectivity:
 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 and adjacent patch j. Aj equals the area of the adjacent patch.\
 near_dist: distance calculated from edge to edge of two adjacent patches
 (m) \ X: X coordinates in the EUREF-FIN ETRS-TM35FIN coordinate system.
 Please note that as these coordinates include sensitive information, we
 have obscured the last 4 digits of both y- and x-coordinates with the
 permission of the journal. The analyses run with these obscured
 coordinates will therefore likely give different results than those
 reported in the article, and are not correct. \ Y: Y coordinates in the
 EUREF-FIN ETRS-TM35FIN coordinate system. Please note that as these
 coordinates include sensitive information, we have obscured the last 4
 digits of both y- and x-coordinates with the permission of the journal.
 The analyses run with these obscured coordinates will therefore likely
 give different results than those reported in the article, and are not
 correct.\ N: Total soil nitrogen (%) averaged per site from air-dried
 samples and analysed with the Flash Smart CHNS/O (Thermo Scientific).\
 Moisture: Soil moisture (VWC%; TDR 100, Spectrum Technologies, USA)
 averaged per site measured during plant community sampling\
 Artificial_surface_percent_1000m: percentage of land cover type Artificial
 Surface within 1000 m of the edge of the patch. Calculation based on 20 m
 spatial resolution CORINE Land Cover 2018 data from the Finnish
 Environment Institute (Syke)
 ([https://ckan.ymparisto.fi/dataset/corine-maanpeite-2018](https://ckan.ymparisto.fi/dataset/corine-maanpeite-2018)).\ Artificial_surface_percent_100m: percentage of land cover type Artificial Surface within 100 m of the edge of the patch. Calculation based on 20 m spatial resolution CORINE Land Cover 2018 data from the Finnish Environment Institute (Syke) ([https://ckan.ymparisto.fi/dataset/corine-maanpeite-2018](https://ckan.ymparisto.fi/dataset/corine-maanpeite-2018)).\ Arable_land_plantations_percent_1000m: percentage of land cover type Arable Lands within 1000 m of the edge of the patch. Calculation based on 20 m spatial resolution CORINE Land Cover 2018 data from the Finnish Environment Institute (Syke) ([https://ckan.ymparisto.fi/dataset/corine-maanpeite-2018](https://ckan.ymparisto.fi/dataset/corine-maanpeite-2018)).\ Arable_land_plantations_percent_100m: percentage of land cover type Arable Lands within 100 m of the edge of the patch. Calculation based on 20 m spatial resolution CORINE Land Cover 2018 data from the Finnish Environment Institute (Syke) ([https://ckan.ymparisto.fi/dataset/corine-maanpeite-2018](https://ckan.ymparisto.fi/dataset/corine-maanpeite-2018)).\ Forest_percent_1000m: percentage of land cover type Forest within 1000 m of the edge of the patch. Calculation based on 20 m spatial resolution CORINE Land Cover 2018 data from the Finnish Environment Institute (Syke) ([https://ckan.ymparisto.fi/dataset/corine-maanpeite-2018](https://ckan.ymparisto.fi/dataset/corine-maanpeite-2018)).\ Forest_percent_100m: percentage of land cover type Forest within 100 m of the edge of the patch. Calculation based on 20 m spatial resolution CORINE Land Cover 2018 data from the Finnish Environment Institute (Syke) ([https://ckan.ymparisto.fi/dataset/corine-maanpeite-2018](https://ckan.ymparisto.fi/dataset/corine-maanpeite-2018)).\ Water_percent_1000m: percentage of land cover type Water within 1000 m of the edge of the patch. Calculation based on 20 m spatial resolution CORINE Land Cover 2018 data from the Finnish Environment Institute (Syke) ([https://ckan.ymparisto.fi/dataset/corine-maanpeite-2018](https://ckan.ymparisto.fi/dataset/corine-maanpeite-2018)).\ Water_percent_100m: percentage of land cover type Water within 100 m of the edge of the patch. Calculation based on 20 m spatial resolution CORINE Land Cover 2018 data from the Finnish Environment Institute (Syke) ([https://ckan.ymparisto.fi/dataset/corine-maanpeite-2018](https://ckan.ymparisto.fi/dataset/corine-maanpeite-2018)).