Diversifying livestock promotes multidiversity and multifunctionality in managed grasslands

TLDR

Increasing plant diversity can enhance ecosystem functioning, stability, and services in grasslands, but the effects of herbivore diversity, especially livestock diversity, are poorly understood. The study aimed to experimentally evaluate how diversifying livestock (sheep, cattle, or both) affects multidiversity and ecosystem multifunctionality in managed grasslands, and to assess whether multifunctionality depends on multidiversity. Researchers conducted a large-scale grazing experiment in the world’s largest remaining grassland, manipulating livestock species composition and measuring multidiversity across plants, insects, soil microbes, and nematodes, along with multifunctionality indicators such as biomass, nutrient cycling, soil carbon, water regulation, and plant–microbe symbiosis. Livestock diversification markedly increased ecosystem multifunctionality by boosting multidiversity, with the multidiversity–multifunctionality relationship consistently stronger than that of any single diversity component, underscoring the value of multitrophic diversity for sustaining multifunctionality in managed ecosystems.

Abstract

Increasing plant diversity can increase ecosystem functioning, stability, and services in both natural and managed grasslands, but the effects of herbivore diversity, and especially of livestock diversity, remain underexplored. Given that managed grazing is the most extensive land use worldwide, and that land managers can readily change livestock diversity, we experimentally tested how livestock diversification (sheep, cattle, or both) influenced multidiversity (the diversity of plants, insects, soil microbes, and nematodes) and ecosystem multifunctionality (including plant biomass production, plant leaf N and P, above-ground insect abundance, nutrient cycling, soil C stocks, water regulation, and plant–microbe symbiosis) in the world’s largest remaining grassland. We also considered the potential dependence of ecosystem multifunctionality on multidiversity. We found that livestock diversification substantially increased ecosystem multifunctionality by increasing multidiversity. The link between multidiversity and ecosystem multifunctionality was always stronger than the link between single diversity components and functions. Our work provides insights into the importance of multitrophic diversity to maintain multifunctionality in managed ecosystems and suggests that diversifying livestock could promote both multidiversity and ecosystem multifunctionality in an increasingly managed world.