The effects of livestock grazing on biodiversity are multi‐trophic: a meta‐analysis. (5th May 2020)

• Record Type: Journal Article
• Authors: Filazzola, Alessandro; Brown, Charlotte; Dettlaff, Margarete A.; Batbaatar, Amgaa; Grenke, Jessica; Bao, Tan; Peetoom Heida, Isaac; Cahill, James F.
• Editors: Seabloom, Eric
• Is Part Of: Ecology letters. Volume 23:Number 8(2020)
• Page Start: 1298
• Page End: 1309
• Publication Date: 2020-05-05
• Subjects: Conservation -- disturbance -- domestic grazers -- exclosure -- global -- graze -- herbivory -- trophic cascade; Ecology -- Periodicals; 577
• DOI: 10.1111/ele.13527
• Languages: English
• ISSNs: 1461-023X

Abstract

Abstract: Anthropogenic disturbance has generated a significant loss of biodiversity worldwide and grazing by domestic herbivores is a contributing disturbance. Although the effects of grazing on plants are commonly explored, here we address the potential multi‐trophic effects on animal biodiversity (e.g. herbivores, pollinators and predators). We conducted a meta‐analysis on 109 independent studies that tested the response of animals or plants to livestock grazing relative to livestock excluded. Across all animals, livestock exclusion increased abundance and diversity, but these effects were greatest for trophic levels directly dependent on plants, such as herbivores and pollinators. Detritivores were the only trophic level whose abundance decreased with livestock exclusion. We also found that the number of years since livestock was excluded influenced the community and that the effects of grazer exclusion on animal diversity were strongest in temperate climates. These findings synthesise the effects of livestock grazing beyond plants and demonstrate the indirect impacts of livestock grazing on multiple trophic levels in the animal community. We identified the potentially long‐term impacts that livestock grazing can have on lower trophic levels and consequences for biological conservation. We also highlight the potentially inevitable cost to global biodiversity from livestock grazing that must be balanced against socio‐economic benefits. Abstract : Livestock grazing reduces the abundance and diversity of animals, but the effects are dependent on trophic level of responding species. Herbivores and pollinators are most impacted, while detritivores increase with livestock present. There is also an effect of livestock exclusion over time on the animal community.