The Rimba Raya Biodiversity Reserve REDD Project

GHG removals from oil palm sequestration. Growth curves forpalm oil were constructed from literature data. Equations 43-­‐46from the proposed methodology were used to estimate theaccumulation of biomass carbon on the future plantation sites.Biomass data used to formulate a non-­‐linear growth curve arecited in Cannell (1982) but reported originally in Ng et al. (1968).In Malaysia, one or two palms of average size were sampled fromeach high-­‐yielding, fertilized stand on marine clay with fine sandyloams. Stand values were obtained by multiplying mean valuesby the number of palms per hectare (palms ha -­‐1 = 148 at all ageclasses). Dry biomass values for stem wood and bark werecombined with values for branches, fruit, and foliage to computea total aboveground biomass value, which was then multiplied by0.47 to calculate total carbon per hectare. The use of these datais conservative because oil palm would likely have lower growthrates on peat soils than on high-­‐yielding, fertilized stands onmineral soils.Equation 44 of the proposed methodology requires the use offour parameters to calibrate the non-­‐linear growth function.Model parameters for the oil palm growth function are as follow,and modeled growth curve and data points used to fit the curveare shown in Figure 31:MaxYld = 70, Prm1 = 0.176, Prm 2 = 2.5, Prm3 = 0.6It is assumed that the concession areas would have been drained,cleared, and burned one year prior to planting. Planting wasassumed to occur at a rate of 2,000 ha yr -­‐1 , for a total of threeage “cohorts” of trees in the northern two concessions and four“cohorts” of trees in the southernmost concession.Sequestration on each concession is shown in Table 23 below.Aboveground Carbon Stocks (t C/ha)80706050403020100Modeled t C/ha95% CI upper bound95% CI lower boundMeasured Data0 5 10 15 20Stand age (years)r 2 = 0.95Figure 31. Modelled growth curve for oil palm.Emissions from PeatPeat burningBased on pertinent scientific literature, it was assumed thatthe average depth of peat burned for initial land clearing is0.3 m (estimates ranged between 30 and 80 cm). The bulkdensity of peat is assumed to be 0.15 g cm-­‐3 (or t m-­‐3) basedon a review of several sources. Local emission factors forburning peat at 480 C are 185,000 g CO 2 per ton of peat and5,785 g CH4 per ton of peat. Total emissions from peatburned for initial land clearing over the first ten years of theproject are estimated as 5.47 million tCO 2 e, or approximately5,478,802 tCO@e per year over the first ten years (Table 24).114