Experimental rewilding enhances grassland functional composition and pollinator habitat use

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...