Woody biomass increases across three contrasting land uses in Hurungwe, mid-Zambezi valley, Zimbabwe

Abstract

Globally, Miombo woodlands store important quantities of carbon, with tree cover and carbon stocks strongly determined by human use. We assessed woodland cover and aboveground carbon (AGC) stocks of miombo along a utilisation gradient on three different land use types, that is, a national park, a buffer zone and a communal area. Woodland cover and carbon stock changes were assessed through mapping of AGC between 2007 and 2017 using Phased Array L-Band Synthetic Aperture Radar observations (ALOS-PALSAR 1 and 2). Woodland cover was higher in the national park and the buffer zone than in the communal area for both 2007 and 2017. In 2007, mean AGC stock was not significantly different (p = 0.05) across all three land use types. However, in 2017, mean AGC was significantly lower (p < 0.001) in the buffer zone and communal area than in the national park. In all three land use types, Miombo woodland cover and mean AGC gains outweighed losses over the 10-year period. AGC gains were significantly higher (p < 0.001) in the national park than in both the buffer zone and the communal area. Results of the study indicate that woodland cover and aboveground carbon increased in all three land use types despite the observed human disturbance over the study period. Both variables recorded a lower increase with elevated utilisation. The study concluded that sustainable resource utilisation is possible without loss of such ecosystem services as carbon sequestration and climate change mitigation.