Methodology development and simulations for estimating greenhouse gas emission reductions from improved forest management with reduced impact logging

摘要

A method was developed to estimate greenhouse gas (GHG) emission reductions, using a set of calculations to quantify the changes in biomass carbon when conventional logging (CL) is replaced by improved forest management (IFM) with reduced impact logging (RIL). A case study of 30,000 ha net harvestable area of tropical rainforest in Paragominas, Para, Brazil, was employed, where 25 m^ ha“' was harvested over 30 years. To simulate changes from CL to RIL, the residual stand damage factor was reduced from 1.94 to 1.5 Mg C damaged per Mg C extracted, losses in harvested wood volumes were reduced from 16 to 5 while the lumber recovery fraction was increased from 0.47 to 0.55, the area for landing, roads and skid trails was decreased from 20 to 10, andregrowth rate increased from 0.5 to 2.5 Mg of dry matter ha~(-1) yr~(-1). The simulations attained emissions reductions in the order of 3,175,212 Mg COa-e, which equates to 28.8 Mg C ha~(-1) or 0.96 Mg C ha~(-1) yr~(-1), an approximate 82 reduction from CL baseline emissions. The increase in regrowth rate in RIL areas provided the largest affect on emission reductions (51). The simulated results were comparable with both field and model studies, and demonstrate that RIL can achieve carbon credit revenue of USD 105,840 per year, or approximately USD 3,175,212 after 30 years, based on a 2014 carbon price of USD 1.00 per Voluntary Carbon Unit (VCU).