碳汇目标下农户森林经营最优决策及碳汇供给能力——基于浙江和江西两省调查

增加森林碳汇已成为应对气候变化的重要举措.基于浙江和江西两省农户调研数据,以杉木为案例树种,引用生长模型、修正的Faustmann模型碳密度和价格数据,对单一和碳汇木材复合经营目标下的杉木最佳轮伐期和林地期望值进行比较研究,并模拟了不同碳价格和利率水平下的变化,同时绘制了农户的碳汇供给曲线.可以发现,在碳汇林经营模式下,基于目前的杉木市场价格远高于碳价格的现实,农户的经营采伐决策并不会发生明显改变,从而导致在大范围的碳价格变动下碳汇的供给也没有显著增加,这也说明木材收益和碳收益的两个不同经营目标是协调的.同时,基于碳汇经营模式下的杉木林地期望值增长迅速,碳汇林地潜在投资价值巨大,也意味着森林碳汇对于土地利用改变可能会产生巨大影响.

Household optimal forest management decision and carbon supply: case from Zhejiang and Jiangxi Provinces

Using forest for carbon sequestration is widely accepted as an important strategy to mitigate climate change. Using data collected from rural households' survey in Zhejiang and Jiangxi, Faustmann model was applied to investigate the optimal rotation age and forestland expectation value between traditional timber management and joint timber and carbon management for Chinese fir. Carbon supply curve was developed and sensitivity analysis was conducted with various interest rate and carbon price. It was found that the optimal rotation of Chinese fir in the joint management does not change from traditional timber management due to the fact that timber price is much higher than carbon price, suggesting that optimal decision for Chinese fir management will not change significantly and carbon sequestration supply from current Chinese fir forestland would not increase significantly within a large range change of carbon price. However, including carbon value would significantly increase the land value for forest management against alternative land uses, and will expand the forest area, which also increase the carbon storage in the expanded forestland.