地主參與碳給付機制下最適輪伐期與碳吸存成本之分析

A Study on Optimal Forest Rotation and Carbon Sequestration Cost under Carbon Payment Mechanisms

林國慶(Kuo-Ching Lin) ； 柳婉郁(Wan-Yu Liu)

《中華林學季刊》 44卷1期 (2011/03) Pp. 103-119

https://doi.org/10.30064/QJCF.201103.0009

摘要

近年來世界各國開始重視以森林碳吸存作爲二氧化碳排放減量之政策工具，將部份農地轉爲造林地來增加碳吸存。爲提升農地地主造林誘因，政府或社會設計各種碳給付機制。我國目前對於碳吸存與碳釋放並沒有進行補貼或課稅，然而此議題十分重要，並屬未來政策規劃之範圍，故私有地主參與相關碳給付機制所產生之效果是值得關注的問題。本研究推導出地主參與四種碳給付機制下之最適輪伐期，進一步以我國爲例分析我國地主參與四種碳給付機制之最適輪伐期與碳吸存收入與成本。根據本研究之模擬結果，若我國政府實施碳給付機制，則地主不一定會延長輪伐期。當碳給付價格過低時，地主會縮短輪伐期，造成在有碳給付機制下輪伐期反而變得更短。其次，就造林地主之收入而言，地主參加碳給付機制後收入現值會增加，其中又以在逐年給付與事先給付情境下之收入現值增加的幅度最大，木材收入佔總收入之比例會隨著碳給付價格之增加而越來越小；就平均碳成本與邊際碳成本而言，各種給付情境中以理想給付情境之平均碳吸存成本與邊際碳吸存成本最低；整體而言，理想給付機制的政府給付成本較低，而逐年給付機制之地主收入及木材價值相對較高。

關鍵字

最適輪伐期 ； 碳給付機制 ； 森林碳吸存

並列摘要

Recently each country on the world has been emphasizing the policy tools of applying forest carbon sequestration to eliminating carbon emission. While applying those tools to transforming agricultural land into forest land so that the amount of carbon sequestration is increased, the government or the society has to establish economic incentive programs, so as to transform forest carbon sequestration into monetary values and increase the incentives of landowners' afforestation. Although Taiwan has not imposed subsidies or taxes on the emission and storage of carbon sequestration so far, those will be considered in the scope of Taiwan's policy planning in the future. Therefore, the effects of landowners' participation in related programs should be concerned. In this paper, the optimal forest rotation period under four different carbon payment measures is derived, respectively; furthermore, an analysis of the optimal forest rotation and carbon sequestration costs under four carbon payment measures in Taiwan is conducted. According to the results from the above empirical analysis, if the Taiwan government carries out the carbon payment programs, landowners may not always lengthen their forest rotation period. When the level of the carbon payment price is too low, landowners would shorten their forest rotation period, so that the forest rotation period may become much shorter instead. The current value of landowners' income must be increased after landowners participate in carbon payment programs; especially, the range of the increase on the current value of landowners' income is the largest in both the tonne-year and ex-ante full crediting scenarios. The ratio of the timber income to the total income is getting less and less while the carbon price is getter larger; the average and the marginal carbon costs in the ideal payment scenario are the smallest among other scenarios, which are mainly because in this scenario landowners have carbon expenditures while cutting forests so that the cost of the total carbon sequestration of the society becomes less.

並列關鍵字

Optimal Forest Rotation ； Carbon Payment Mechanism ； Carbon Sequestration