Carbon storage potential of trees outside forests under private and communal tenure regimes in ng’iresi village,

Abstract

Though people are getting benefits by favour of ToF in form of lumber, firewood, fruits honey and such products, little has been documented on their potential in timber supply, carbon sequestration and storage. This study was carried out to determine carbon storage potential of Trees outside Forests (ToF) that fall on private and communal tenure regimes in Ng’iresi village, Arumeru district, Tanzania. The village was stratified into 5 main strata; trees around homesteads, agroforestry, woodlots, natural springs, and trees growing in line plantings (along borders of farm blocks, village roads and “Songota” river and its tributary known as “Maridadi”). Trees were measured for diameter at breast height (dbh) and total height for the computation of stand parameters. In addition trees basic densities were obtained through laboratory analysis of the tree cores taken at dbh point. Data on ToF establishment costs (site preparation and planting costs), management costs and revenue accrued from sale of tree products was established based on market prices. The results show that ToF occupied 56% of total area of village land (326 ha). Student’s t-test revealed that ToF under communal tenure regime stored significantly higher amount of carbon (p= 4.35E-08) averaged at 40.35 tC/ha than for private tenure regime estimated at 8.16 tC/ha. The stock parameters of communal tenure regime are higher than for private tenure regime presumably due to type of management in the former which favours less harvesting of trees so as to conserve the natural springs. ToF under communal tenure regime have shown higher and positive land expectation value due to presence of springs which are conserved. It is worth investing on communal ToF land (especially around natural springs/water sheds) so as to get extra benefits including carbon storage benefits.