Integrating random forest classification and Markov chain analysis to assess vegetation and land cover change in the Chobe Enclave, Botswana
摘要
This study evaluated historical changes in land cover in the Chobe Enclave, Botswana, by characterising the landscape and illustrating its spatiotemporal changes to establish insights into the extent to which the National Conservation strategy of 1990 has facilitated conservation of the landscape. Previous research in the area has focused on changes in broad land cover categories, reporting a continuous and ongoing shift from woodlands to shrublands and grasslands. Our study clarifies the species-level dynamics shaping the observed structural change in plant functional types. We used a random forest classifier to identify 15 land covers and account for the fractional cover of photosynthetic and non-photosynthetic vegetation. We confirm an ongoing structural shift in plant functional types. The shift involves the displacement of the historically abundant Colophospermum mopane by generally short-statured communities, such as Terminalia sericea and Dichrostachys cinerea. The Dichrostachys cinerea accounted for 27.5%, 29.0%, 30.5%, and 25.3% in 1990, 2000, 2010, and 2020, respectively. Concurrently, the Terminalia sericea accounted for 24.3%, 25.1%, 28.1%, and 25.6% in 1990, 2000, 2010, and 2020, respectively. The communities showed aggressive encroachment towards the Colophospermum mopane, alongside other confounding factors. In this case, the vegetation was inversely correlated to elephant, cattle, and buffalo populations at rs = −0.8, −0.8, and −0.2, respectively. The observations highlight that the envisioned sustainable management of natural resources through the National Conservation Strategy has not been fully addressed, as indicated by the continual disruption of the ecological integrity of the landscape and the detrimental implications posed on the support services it provides.