Sheep and Goat Grazing in Sustainable Agroecosystems: A Meta-Analysis of Soil Functioning, Biodiversity, and Climate Trade-Offs

Sheep and goats play a multifunctional role in agroecosystems, extending beyond their traditional

contribution to food production. This study aimed to synthesize the environmental impacts of small

ruminant grazing on soil functioning, biodiversity, and climate-related processes using a metaanalytical framework. A systematic literature search was conducted across major scientific

databases, and studies meeting predefined inclusion criteria were evaluated using a random-effects

model. Effect sizes were expressed as log response ratios (lnRR) to compare grazed and non-grazed

or differently managed systems. The results indicated that grazing by sheep and goats had a positive

effect on soil organic carbon (SOC) (mean lnRR = 0.120), suggesting enhanced carbon

sequestration potential under appropriate management conditions. Biodiversity responses were

even stronger (mean lnRR = 0.215), reflecting increased plant species richness and habitat

heterogeneity. In contrast, greenhouse gas (GHG) emissions exhibited a negative effect size (lnRR

= −0.143), indicating potential reductions in emission intensity under well-managed grazing

systems. Heterogeneity among studies was moderate to high (I² = 64%), highlighting the importance

of context-dependent factors such as grazing intensity, ecosystem type, and species composition.

Subgroup analyses demonstrated that moderate grazing intensity and mixed grazing systems

produced the most favourable environmental outcomes. Overall, the findings suggest that small

ruminants can function as ecological regulators within agroecosystems, with their environmental

impact being strongly dependent on management practices. This study provides quantitative

evidence supporting the integration of sheep and goat systems into sustainable land-use strategies

and climate-resilient agricultural frameworks.