How has woody vegetation changed in north-east Namibia in response to land use, climate and fire?

Bush encroachment or the thickening of woody vegetation is a phenomenon occurring throughout savannas, which tends to be more pronounced in small protected areas. The consequences of bush encroachment are often negative for the conservation of biodiversity, for the promotion of tourism and the prevention of wildfires. Hence, effective monitoring of woody vegetation and the factors which influence its spread are essential. This is particularly the case for protected areas such as that of Bwabwata National Park (BNP) in north-east Namibia. With a complex land use history and different fire management approaches being adopted throughout the area, the effect of fire on woody vegetation in BNP is currently poorly understood. This study used a 20-year-old repeat photography monitoring project and satellite-based remote sensing products to explore woody cover dynamics in BNP. Results revealed that woody cover has increased by 13% since 1999 in BNP. Furthermore, the results show differences in the structure of woody vegetation. Repeated late dry season fires in the west of the park have driven an increasing dominance of 3m in eastern sections of the park. This influence of different fire regimes spatially across BNP, suggests that local fire management is a significant determinant of woody vegetation change. Woody vegetation change differs spatially across BNP due to frequent late dry season fires prevailing in the west and less frequent earlier season fires occurring in the east. Therefore, in order to reduce the mortality of woody species and conserve heterogenous height structure in the west, a reduction of frequent late dry season fires is required. Early dry season fires are shown to reduce the rate of increasing total woody cover change and, therefore, this fire management strategy arguably contributes towards the reduction of wildfire risk, conservation of biodiversity and promotion of tourism.

Grantor

FitzPatrick Institute of African Ornithology

Year dc:date.issued

2020

Author dc:creator

• Eastment, Conor

Advisors dc:contributor.advisor

• Gillson, Lindsey
• Humphrey, Glynis
• Hoffman, Timm

• Conservation Biology
• woody vegetation change
• repeat photography
• fire management

Handle dc:identifier.uri

http://hdl.handle.net/11427/32258

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/32258