Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Megaherbivore Distributions and Their Effects on Savanna Herbivore Community Structure

Auteur : Hartfelder, Jack Oliver

Université de soutenance : University of Florida

Grade : Master of Science (MS) 2021

Résumé
To properly understand the basic ecology of a species, it is necessary to understand its distribution and its impacts on the environment around them. The distribution of one species may directly and indirectly affect the distributions of countless others. This is especially pronounced in megaherbivores, plant-feeding mammals weighing over 1000 kilograms. Megaherbivores play a critical role in structuring ecosystems but we often have a limited understanding of their spatial extent and the mechanics behind their impacts on ecosystems Our study investigated the environmental determinants of megaherbivores and how those megaherbivores are shaping the community of animals around them. We used megaherbivores and a suite of meso-herbivores in Kruger National Park, South Africa, to meet our research goals. Our objectives were to understand the factors associated with the distribution of megaherbivores and understand the role megaherbivores have in structuring the meso-herbivore community. We identified key environmental features, like surface water availability and woody canopy cover effect on megaherbivores daytime distribution. These responses are potentially concerning as current and future projections of global change suggest reductions of surface water and increases in canopy cover across African savannas. We also demonstrated that even over a short temporal period (6-12 months) megaherbivores can impact the structuring of meso-herbivore communities around them through positive interactions with browsing species. Megaherbivores are extremely sensitive to human impacts and vulnerable to extinction, making these results highly valuable to their conservation

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