PhD defence Yuhong Li
Yuhong Li (ConsEco)
Promotor: Prof. H. Olff; copromotor: Dr M.P. Veldhuis (Leiden University)
Forage quality and resource partitioning of herbivores across a protected area and rangelands
Conserving biodiversity is one of the most pressing challenges facing humanity. Although protected areas are central to conservation strategies, they often fail to capture the full spatial dynamics of ecosystems or the movements of wildlife populations. Many species therefore depend on surrounding multi-use landscapes. Rangelands—extensively managed ecosystems dominated by grasses, forbs, and shrubs—cover vast areas of the Earth and support both wildlife and pastoralist livelihoods. Understanding ecological processes across the interface between protected areas and pastoral lands is therefore crucial for conserving biodiversity while sustaining human livelihoods.
This thesis examines how large-scale environmental gradients and land use shape forage resources, vegetation diversity, and herbivore resource use across the Greater Serengeti–Mara Ecosystem in northern Tanzania. First, it shows that spatial variation in plant nutrient availability arises from both species turnover and within-species variation, with their relative importance differing among nutrients. These patterns can shape how herbivores partition resources in space and among plant species. Second, comparisons between protected areas and adjacent rangelands reveal that livestock grazing can replace fire as the dominant consumer of grass biomass and override natural environmental gradients, creating more homogeneous but nutrient-rich forage landscapes. Third, livestock grazing increases local plant diversity while reducing compositional differences among sites, yet pastoral lands maintain distinct plant communities. Finally, livestock alter herbivore diets and coexistence patterns by reducing resources for grazers while facilitating some non-grazer species. Together, these findings highlight that rangelands are not merely buffer zones but can play an important role in sustaining biodiversity in human-dominated landscapes.
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