The effects of repeated cutting on coppice response of Terminalia sericea

Abstract

Key message: Although exposure to multiple cutting cycles reduces stored reserves, shootdiameter and shoot length, it, however, increases shoot production per resprouting stump and foliar nitrogen. Abstract: In disturbance-prone environments with fluctuating seasonal rainfall such as savannas, the repeated cutting of the same trees eventually results in a possible decline in tree abundance. The effects of subjecting Terminalia sericea trees to one, two and multiple (eight) cutting events over a period of 2 years on coppice response were investigated in a savanna woodland in South Africa. Resprout shoot diameter, shoot length and the total cumulative diameter were lower in trees exposed to a high number of cutting events compared to trees exposed to one cutting event. Increasing the number of cutting events significantly reduced stem total non-structural carbohydrate levels in trees indicating a depletion of stored reserves. Foliar carbon content remained largely the same, while leaf nitrogen and phosphorus concentrations significantly increased with each cutting event, relative to uncut trees. Results indicate that trees cut once had not replenished depleted carbohydrate reserves even after a period of 18 months during which no cutting took place. Sustainable utilization of this tree species must allow for at least more than 18 months of undisturbed growth between harvests to allow for the replenishing of reserves.