DOI: 10.5061/dryad.m2t17cc
title: Data from: Experimental rewilding enhances grassland functional composition and pollinator habitat use

description: 1. Semi-natural grasslands are rich in biodiversity and thus important
 habitats for conservation, yet subjected to rapid declines due to
 agricultural intensification or abandonment. Promoting a more diverse
 mammalian herbivore community, including large and megaherbivores, may
 result in positive cascade effects for biodiversity and ecosystem
 functioning. Therefore, reintroducing an ecologically functional
 substitute of an extinct large herbivore could mitigate current
 biodiversity declines and foster semi-natural grassland conservation. 2.
 To test this hypothesis, we set up a 3-year rewilding experiment where 12
 feral horses were introduced in three 10-hectare enclosure replicates
 (four horses per enclosure). We used community-weighted mean plant
 functional traits to elucidate plant community changes induced by grazing
 through time. We additionally investigated the effects of the experimental
 treatment on insect pollinated plants and on pollinator habitat use. 3.
 The grassland community exerted a mixed tolerance/avoidance response to
 grazing. This resulted in plant functional compositional changes which
 favoured prostrate plant species with higher specific leaf area,
 characteristic of ruderal communities. 4. Plant species richness was
 higher in grazed compared to ungrazed areas. Butterfly and bumblebee
 habitat use, as well as feeding and resting activities were also higher in
 grazed areas. Moreover, the number of pollinators increased with plant
 species richness. 5. Synthesis and applications. This study demonstrates
 that to enhance the diversity of a given herbivore community with an
 ecologically functional substitute of extinct wild horses can have
 significant effects on the functional composition of grasslands, mitigate
 plant species declines, and boost pollinator habitat use. Thus, rewilding
 interventions with large herbivores may offset current biodiversity
 declines by maintaining important functional links between plants and
 pollinators in grassland ecosystems.
description: Grime's CSR trait
 dataCommunity Weighted Mean
 values of CSR to test the changes of the grassland community in relation
 to grazing and timecsr trait
 data.csvWestoby's LHS trait
 dataCommunity Weighted Mean
 (log-transformed) LHS trait values to test the effect of horse grazing and
 time on the functional composition of grasslandslhs trait
 data.csvButterfly and Bumblebee
 counts in relation to plantspecies richnessButterfly and Bumblebee
 counts and feeding and resting activities in relation to mean number of
 plant species per plotpollinator and plant
 richness.csvPollinator species and
 behaviour in relation to treatmentButterfly and Bumblebee
 species counts and feeding and resting activities in relation to
 treatment, i.e., grazed vs ungrazed conditionspollinator species and
 behaviour.csvWind pollinated plant
 coverWind-pollinated plant
 cover to test the effect of grazing and timewind pollinated
 plants.csvGeneralist pollinated
 plant coverGeneralist insect
 pollinated plant cover to test the effect of grazing and time in such
 plantsgeneralist pollinated
 plants.csvBee pollinated plant
 coverCover of plants needing
 pollination by bees to test the effect of gazing and time on
 thembeepollinated
 plants.csvPlant species richness
 dataPlant species richness
 at plot level to test the effect of the treatment (grazed vs ungrazed
 conditions) and time on plant species richnessplant species richness
 data.csv