考量碳給付與病蟲害對土地期望價值之經濟分析

The Effects of the Pests and Diseases on the Optimal Forest Rotation and Land Expected Value Considering the Payment of Environmental Services

病蟲害對環境資源管理與土地利用管理決策有著重大影響，根據前人文獻可知，臺灣關於病蟲害影響土地期望價值與最適輪伐期之著作付之闕如，因此本研究考慮病蟲害與碳給付影響土地期望價值與最適輪伐期之研究，將臺灣的林業現況應用於其中，模擬病蟲害對臺灣森林經營之最適輪伐期與最大土地期望價值的影響。由本研究之模擬結果顯示，與無病蟲害之情境相較，病蟲害存在之情境有較短的最適輪伐期與較低的最大土地期望價值。由本研究之敏感度分析顯示，在無病蟲害與病蟲害存在之情境下，碳價格、單位木材價格及伐採後地租收入 (材積分收率) 的提高將延長最適輪伐期與增加最大土地期望價值，伐採成本及伐採後碳釋放比例的提高將延長最適輪伐期與減少最大土地期望價值，折現率的提高將縮短最適輪伐期與減少最大土地期望價值；而在病蟲害存在之情境下發現感染率的提升不一定縮短最適輪伐期，但最大土地期望價值將會降低。

 

Pets and disease have many impacts on the environmental management and land use decision-making. Previous works less discussed about the effect of disease and carbon payment on the optimal rotation length. This study models the effect of disease on the optimal rotation length and the maximum land expectation value of Taiwan forest management. In the empitical analysis of this study, the situation of disease has a shorter optimal rotation length and a lower maximum land expectation value than the situation of no disease. In the sensitivity analysis of this study, at the both of the situation of no disease and disease, the increase of the carbon price, per-cubic-metre price of timber and land rent after harvesting (distribution rate of timber volumn) will increase the optimal rotation length and maximum land expectation value. The increase of the timber logging cost and carbon release rate after harvesting will increase the optimal rotation length and decrease the maximum land expectation value. The increase of the discount rate will decrease the optimal rotation length and maximum land expectation value. In the situation of disease, the increase of the infection rate will not necessarily decrease the optimal rotation length, but the maximum land expectation value will be decreased.