A Spatio-Temporal Based Estimation of Sequestered Carbon in the Tarkwa Mining Area of Ghana

Abstract

The vegetation in the Tarkwa Mining Area (TMA) has experienced changes as a result of population growth, urbanization, mining activities and illegal chainsaw operations and this has led to an increase in temperature over the past years. Therefore, studying its forest biomass carbon (C) stock and its spatio-temporal change is important to the sustainability of forest resources and understanding of the forest C budget in the TMA. In this study, aboveground forest biomass/carbon stock and its changes in the TMA were estimated from three nested-circular plots of horizontal radii 12.62 m, 8 m and 4 m using stratified random sampling from sixty locations in five land use/cover types as well as GIS/Remote Sensing techniques over a 21 year period. An estimated total of 1 250.93 ± 7 Mg/km² carbon was recorded in the TMA. Carbon in different land-use/cover types ranges from 587.76 ± 4 Mg/km² carbon in closed canopy to 270.23 ± 2 Mg/km² carbon in shrubs/herbaceous. The TMA also experienced an average of 412.14 Gg of carbon (equivalent to 19.63 Gg carbon per year) lost between 1986 and 2007 due to the changes in the land use/cover types. The study area is however, considered a net source of carbon.

Keywords: Spatio-Temporal, Carbon, Mining, Biomass, GIS