Compositional distinctiveness and patterns of woody species abundance distribution in Ghana’s Mole National Park, Savannah Region

Abstract

Abstract The vegetation in many African national parks is undergoing notable changes due to disturbances at various spatial and temporal scales. Understanding the responses of species can help with predicting future impacts of human-induced disturbance-related drivers on the vegetation in Mole National Park. This study aimed to examine how woody species react to disturbance-related factors in five vegetation types (woodland, savannah forest, riparian forest, swamp forest, and boval vegetation) across the park. We tested the hypothesis that the effects of wildfires, herbivory activities, invasive alien plant species, erosion, and bare ground on the tree community structure differ among the five vegetation types, as individual species respond differently to these drivers. Our results showed that the impact of fire regimes, invasive alien plant species, herbivory, erosion, and bare ground accounted for 59% of the low abundance of the individuals observed in the riparian and swamp forest vegetation types. Similar disturbances, especially fire regimes and invasive alien plants, also contributed to the presence of rarer species such as Afraegle paniculata and Isoberlinia doka in the woodland and boval vegetation types. However, the dominance and wide distribution of Detarium microcarpum, Combretum adenogonium, Terminalia avicennioides, and Icacina senegalensis in these two vegetation types suggest their resistance to these disturbance-related factors, particularly fire regimes, through the use of adaptive fire-cued mechanisms. We conclude that increased disturbances may lead to the extinction of many rarer species, while the few resistant and resilient species are likely to experience a decline in their populations in such resource-limited environments.