Ecological niche modelling of Brachystegia spiciformis in Southern Africa

Author

Shungu, Princess V.

Title

Ecological niche modelling of Brachystegia spiciformis in Southern Africa

Abstract

Climate change is a serious global environmental issue, negatively impacting species distribution. Brachystegia spiciformis is a tree species that is endemic to Southern Africa. The tree species is currently identified as 'Least Concern' according to the IUCN Red List of Endangered Species, as it is not significantly threatened by habitat degradation or population decline, among others. However, the likely effects of climate change on this species remain unaccounted for and hence require further study. Understanding why species inhabit their current locations and forecasting where they might relocate under various climate change scenarios is crucial to biodiversity conservation. Considering how climate change is progressing, species modelling is one of the powerful tools that can aid biodiversity conservation as it helps predict species distribution under different climate change possibilities. This study determined to model the current distribution of B. spiciformis and predict its distributions under distinct environmental future scenarios using the Maximum Entropy (Maxent) method. The future distribution was forecasted for 2061-2080 and 2081- 2100 under three Shared Socio-economic Pathways, which are SSP126, SSP245 and SSP585 scenarios. Four thousand sixty-six species presence records and five bioclimatic variables (Bio 1, Bio 3, Bio 5, Bio 13 and Bio 15) were used to model the species' distribution. The results suggest that annual mean Temperature (Bio1), precipitation of the wettest month (Bio13) and precipitation seasonality (Bio15) were the most important variables determining the current distribution of B. spiciformis. While the species' current range appears relatively stable, the future projections indicate a potential northward shift in suitable habitat under all climate change scenarios. By 2100, the suitable area is predicted to decrease by 15-32% compared to the current distribution. Even though the findings of this particular study give valuable insight into the potential impacts of climate change on this essential species in Southern Africa, the outcomes must be grasped cautiously and further research is needed to develop robust conservation and management strategies. Integrating these ecological niche modelling results with on-the-ground monitoring and adaptation measures will ensure the long-term persistence of B. spiciformis in the region.

Date

May 2024

Publisher

BUSE

Keywords

Climate change

Ecological niche modelling

Species distribution

Brachystegia spiciformis

Southern Africa

Supervisor

Dr. A. Mureva,