# Livestock grazing boosts plant diversity in the Greater Serengeti–Mara Ecosystem

## TL;DR

Livestock grazing in the Serengeti-Mara area boosts plant diversity by reducing competition and creating new habitats.

## Contribution

The study shows livestock grazing increases plant diversity and suggests conservation should include managed grazing.

## Key findings

- Livestock grazing increased alpha diversity by 71%, especially for forbs.
- Livestock grazing areas had 85 unique plant species compared to protected areas.
- Grazing reduces competition and fire, promoting plant coexistence and diversity.

## Abstract

Intensifying land use is a global threat to biodiversity, and livestock grazing—occupying 26% of terrestrial land—is one of such threats. Designated protected areas are one of the key conservation strategies to halt biodiversity loss, but their effectiveness is debated, in part because of data shortage at relevant spatial scales (>1 ha). We investigate how livestock grazing affects plant diversity in the Greater Serengeti–Mara Ecosystem, Tanzania. We recorded plant diversity in sites with and without livestock across different scales: from 1‐m2 plots to nine sites spanning a 600–1000 mm year−1 rainfall gradient. We find livestock grazing strongly increased alpha diversity (71%), with forb species richness increasing the most. Beta diversity decreased in pastoral areas both within and between sites. The total number of plant species at the landscape level was almost the same in Maasai rangelands (N = 210) and Serengeti National Park (N = 212), with a distinct vegetation composition and 85 unique species in livestock‐grazed areas. Our results suggest that livestock grazing—reducing light competition and eliminating fire—facilitates coexistence at local scales, biotically homogenizes across the rainfall gradient, yet provides novel niches at the landscape scale. We conclude that livestock grazing in the Greater Serengeti–Mara Ecosystem—with a long history of pastoralism—increases plant diversity by creating a diverse and distinct plant community, so that a mosaic of livestock‐grazed and ungrazed areas yields the highest value for conservation. We recommend rethinking current conservation strategies that focus on expanding protected area cover and upgrading protected area status, and instead invest in facilitating local communities in their efforts to sustainably coexist with nature.