Data from: navigating uncertainty: managing herbivore communities enhances savanna ecosystem resilience under climate change

Savannas are characterized by water scarcity and degradation, making them
highly vulnerable to increased uncertainties in water availability
resulting from climate change. This poses a significant threat to
ecosystem services and rural livelihoods that depend on them. In addition,
the lack of consensus among climate models on precipitation change makes
it difficult for land managers to plan for the future. Therefore, savanna
rangeland management needs to develop strategies that can sustain savanna
resilience and avoid tipping points under an uncertain future climate. Our
study aims to analyze the impacts of climate change and rangeland
management on degradation in savanna ecosystems of southern Africa,
providing insights for the management of semi-arid savannas under
uncertain conditions worldwide. To achieve this, we simulated the effects
of projected changes in temperature and precipitation, as predicted by ten
global climate models, on water resources and vegetation (cover,
functional diversity, tipping points (transition from grass-dominated to
shrub-dominated vegetation)). We simulated three different rangeland
management options (herbivore community dominated by grazers, by browser
and by mixed-feeders), each with low and high animal densities using the
ecohydrological model EcoHyD. Our results identified intensive grazing as
the primary contributor to the increased risk of degradation in response
to changing climatic conditions across all climate change scenarios. This
degradation encompassed a reduction in available water for plant growth
within the context of predicted climate change. It also entails a decline
in the overall vegetation cover, the loss of functionally important plant
species, and the inefficient utilization of available water resources,
leading to earlier tipping points. Our findings underscore that in the
face of climate uncertainty, farmers' most effective strategy for
securing their livelihoods and ecosystem stability is to integrate
browsers and apply management of mixed herbivore communities. This
management approach not only significantly delays or averts tipping points
but also maintained greater plant functional diversity, fostering a more
robust and resilient ecosystem that acts as a vital buffer against adverse
climatic conditions.