美国怀俄明州西黄松林分碳库和经济收益比较

Comparisons of carbon pools and economic profitability for managed ponderosa pine stands in Wyoming,USA

A forest carbon (C) sequestration project was conducted to evaluate the economic incentives that would be required by landowners to engage in C trading under different management regimes. Costs associated with joint management for C sequestration and timber would be valuable for establishing sound forest C trading systems. In this study, we calculated the C yield and amortized value of three Wyoming, ponderosa pine stands. The management practices examined were, unmanaged, even-aged (regeneration after clear-cut) and uneven-aged (selectively harvested). Costs and revenues associated with three stands were converted into 2006 real dollars using the all commodity producer price index to facilitate a comparison among the net revenues of three stands. Net revenues were annualized using a conservative annual interest rate of 4.5%. Our even-aged stand had the highest annual average C yield of 2.48 Mg·ha^?1·a¹, whereas, the uneven-aged stand had the lowest C accumulation (1.98 Mg·ha^?1·a^?1). Alternatively, the even-aged stand had the highest amortized net return of $276·ha^?1·a^?1 and the unmanaged stand had the lowest net return of $276·ha^?1·a^?1 and the unmanaged stand had the lowest net return of 64 ·ha^?1·a^?1. On the plots examined, an annual payment of $22 for each additional Mg of C sequestered would encourage a change from uneven aged management to an unmanaged stand that sequesters additional C, in the absence of transactions costs.