Biodiversity of bats in Africa: Baobab (Adansonia digitata) reproductive success with focus on fruit bat pollination services and multidimensionality of bat assemblage along an elevation gradient

Biodiversity is a critical driver of ecosystem resilience and function and can be characterized in a multitude of ways. Bats are a diverse taxonomic group that provide ecosystem services in the form of pollination, seed dispersal, and pest consumption. One such bat-pollinated system is the baobab (Adansonia digitata) pollination system, where fruit bat and hawkmoth pollination occur regionally. Characteristics of pollinators, including flight capability, body size, and dietary restraints, influence their pollinator efficacy, which has direct impacts on baobab reproductive success. This dissertation aimed to further research two factors of baobab pollination ecology. The first determined how differences in pollinator characteristics producing likely variation in pollen load, genetic diversity of pollen donors, and number of pollen donors would affect baobab reproductive success. This was accomplished with a hand-pollination experiment in South African baobabs. Baobabs were found to experience pollen limitation in southern Africa. The second assessed the interplay of individual baobab characteristics and landscape context surrounding a baobab in affecting reproductive success, with an emphasis on fruit bat foraging behavior. Fruit production, landscape variables, and individual baobab metrics in south-central Kenya were quantified to identify the relative effects across multiple spatial scales. At small spatial scales—nearer a baobab—individual baobab characteristics were more important to reproductive success, but at larger scales, landscape variables were primary drivers. Pollination is one of many ecosystem services sustained by biodiverse ecosystems. Biodiversity is multidimensional, and quantifying aspects of taxonomic, functional, and phylogenetic diversity are now commonplace in ecological studies. Bats, including insectivores and baobab-pollinating frugivores on mainland Africa, are subject to many environmental limitations, including vast elevational changes. The third goal of this dissertation quantified taxonomic, functional, and phylogenetic diversity across a broad-scale elevational gradient. This was accomplished using museum records and genetic sequences of bats in and near Mount Elgon National Park. In addition, taxonomic classification was evaluated for its effect on quantifying biodiversity. Taxonomic diversity significantly declined with elevation gain whereas functional and phylogenetic diversity did not. Taxonomic and phylogenetic beta diversity were primarily driven by turnover whereas functional beta diversity was driven by nestedness. Taxonomic diversity experienced no effect of taxonomic generalization, whereas functional and phylogenetic diversity indices were significantly altered by broadening taxonomic classification.