Post-exploitation bark recovery rates of some medicinal tree species in Ghana

Abstract

Unregulated harvest of tree bark for medicinal purposes has led to overexploitation and extinction of some valuable tree species. The study assessed bark recovery rates of four medicinal tree species and determined their regenerative abilities, stress shoot production and susceptibility to wood borers. A total of 192 trees of Bombax buonopozense, Mangifera indica, Azadirachta indica and Blighia sapida were randomly selected outside protected forests in the Moist Semi-deciduous (MSD) and Guinea Savannah (GS) ecological zones of Ghana. The trees were harvested using three harvesting intensities, 25%, 50%, and 75% bark removal. Edge and sheet re-growth, stress shoot production and wood borer attack were recorded for each tree in twelfth months. Our results show that the bark of B. buonopozense (29.4% at MSD and 21.4% at GS), M. indica (22.3% at MSD and 16.1% at GS) and A. indica (13.5% at MSD and 12.8% at GS) showed higher regeneration percentage compared to B. sapida (3.8% at MSD and 3.7% at GS), while stress shoot growth percentage was limited to only B. buonopozense (4.7% at MSD and 25% at GS). Though no tree died during the study period, borer attack was recorded for all the species except A. indica. We recommend that forest managers should allow minimum harvesting of B. sapida as they showed slow recovery, while rotation period for repeated harvest can also be prescribed for B. buonopozense and M. indica. Moreover, the coppicing ability of B. buonopozense needs to be examined since it produced a higher number of stress shoots.