A METHOD FOR ESTIMATING THE CURRENT AND FUTURE CARBON CONTENT OF STANDING BIOMASS APPLIED TO GISHWATI FOREST RESERVE, RWANDA

摘要

The carbon content of standing tree biomass was determined in the Gishwati Forest Reserve in north-western Rwanda and growth potential of the forest was estimated using a straightforward, generalisable model of natural forest regeneration. A survey was conducted on 2289 trees in plots throughout the reserve. Wood density data were obtained from literature and tree biomass was estimated using a recent pan-tropical allometric equation. A survey on United Nations Framework Convention on Climate Change (UNFCCC) Clean Development Mechanism (CDM) projects showed that current methods of growth rate projection for mixed, non-plantation forests might significantly overestimate the amount of carbon sequestered. The current study identified an alternative potential method for the estimation of sequestration rates that did not depend upon compiling single-species growth rates and reduced the risk that error would lead to significant over- or underestimation of total biomass sequestration potential. This method used remote-sensing data to estimate total biomass potential in a mature forest based upon local samples and assumes a standard growth trajectory based upon literature values. The benefits in terms of accuracy and ease of model construction are likely to be high. It was found that tree biomass in Gishwati forest contained 53.9 +/- 10 CO2 equivalent(e) ha(-1) and was expected to sequester an average of 1.01 (0.80-1.38) Mg CO(2)e ha(-1) per annum over the next 30 years.