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...1. 半自然草原（semi-natural grasslands）生物多样性丰富，是重要的保护生境，但因农业集约化或弃耕而正经历快速衰退。培育包含大型及巨型草食动物在内的更多样化的哺乳动物草食动物群落，或可为生物多样性与生态系统功能带来正向级联效应。因此，重新引入已灭绝大型草食动物的生态功能替代物，或可缓解当前的生物多样性衰退，助力半自然草原保护。2. 为验证这一假说，我们开展了一项为期3年的再野化实验（rewilding experiment）：将12匹野化马（feral horses）引入3个面积为10公顷的重复围栏样地中，每个围栏样地放养4匹马。我们采用群落加权平均植物功能性状（community-weighted mean plant functional traits），阐明放牧随时间推移对植物群落造成的改变；此外，我们还探究了该实验处理对虫媒植物（insect pollinated plants）及传粉者生境利用（pollinator habitat use）的影响。3. 该草原群落……