Species composition and phytogeographical significance of an afromontane forest fragment in the Mpumalanga province, South Africa

Abstract

SYNOPSIS A floristic survey of an afromontane forest fragment, Pedlar's Bush, was done as part of an effort to proclaim this forest as a national heritage site. A checklist of 245 plant taxa has been compiled for Pedlar's Bush. The phytogeographical relationship of this forest with thirteen Afromontane and Coastal Lowland forests of the region was also investigated. Results show that Pedlar's Bush consists of tree species rare and uncommon for the region. The forest is also phytogeographically important because it forms a centre where species distribution endpoints overlap. The forest contains a number of tropical afromontane species such as Cola greenwayi var. greenwayi, Allophylus chaunostachys, Aphloia theiformis and Ocotea kenyensis which have a restricted and geographically isolated distribution pattern in South Africa. Pedlar's Bush is also situated on the periphery of a number of tree species distribution patterns, such as Chionanthus foveolatus subsp. major, Garcinia gerrardii, Maytenus nemorosa and Cryptocarya transvaalensis. Pedlar's Bush forms part of a system of forest fragments that contain a number of endemic species such as Pavetta barbertonensis, Heteropyxis canescens, Bowkeria cymosa, Polystichum macleae and Streptocarpus wilmsii on the eastern Drakensberg Escarpment. Results indicated the phytogeographical importance of this and probably other forest in the region of Barberton. Conservation of Pedlar's Bush, as largest remaining fragment, must be considered of high priority.