기후변화협약에 대응한 산림의 역할과 관리 최적화 방안

Abstract

이 연구는 기후변화협약에 적극 대처하며 타산업의 부담을 감소하기 위한 산림의 역할을 규명하고, 온실가스 배출 및 흡수를 감안한 지속가능한 산림관리의 적정성을 판단하여 최적화된 온실가스 흡수원으로서의 산림 부문 관리방안을 마련하는 데 목적이 있다.

산림을 이용한 기후변화 완화방안에는 재조림과 신규조림을 통하여 탄소흡수원을 확충하는 방법, 효율적인 산림경영을 통하여 탄소흡수를 최대화하는 방법 등이 있다. 현재 선진국들은 탄소배출권을 인정받기 위하여 산림부문에서 신규조림, 재조림, 산림전용 및 산림경영활동 등에 대한 정책을 수립하고 있다. 특히, 비용과 시간이 많이 드는 신규조림 및 재조림 보다는 산림경영활동을 통한 탄소배출권을 인정받기 위한 노력이 지속적으로 이루어지고 있으며, 의무당사국 대부분이 산림경영을 기후변화협약하의 산림활동으로 선택하고 있다. 그러나 이러한 노력들은 대부분 사회경제적 가치를 고려한 산림경영의 효율성에 대해서는 간과하고 있는 실정이다. 산림경영에 따른 탄소흡수 및 배출의 탄소계정은 산림 전체 차원에서 매년 계산되지만, 이를 증가시키기 위해서는 결국 임분 단위에서 탄소의 흡수를 증가시킬 수 있는 방안을 마련할 필요가 있다.

This study is design to define the roles of forest and to find the optimized management schemes if the value of carbon abatement is included in existing forest stands. Mitigation schemes to climate change by forest include reforestation, afforestation and efficient forest management to maximize carbon absorption. Many Annex I industrialized countries try to establish various policies for forest carbon abatement, which can be approved as permissions or credits of carbon emission from Kyoto Protocol. They prefer to focus on forest management rather than expensive reforestation or afforestation. These countries take forest management under Convention on Climate Change as forest management schemes. These efforts to get permissions or credits for carbon emission, however, do not consider the efficiency of forest management, which includes socioeconomic values. Each country needs to account carbon relevant to forest management as a whole, but schemes for each stands are required to enhance carbon absorption. Therefore this study finds optimal forest management schemes. The rotation period is extended if the value of carbon absorption as well as the timber values are considered for the stands of pine trees and Korean pine trees. The current management method is also analyzed and compared with the optimal scheme. The result says that for the case of pine trees the rotation period is optimal with the current method. But the rotation period decreases and the function value(objective value) increases if the optimal scheme is applied. The reasons are that the late execution of the second thinning brings about slow progress of volume increment and extends rotation period. By the longer rotation period the present value from stands are discounted more seriously. To enhance the value of stands the current rotation should be shorten, and the thinning should be executed at a time. For the case of Korean pine trees the current rotation period is too short, and it is not optimal even under current management method. Under the optimal management scheme, however, the rotation period becomes shorter than the current method. This happens because the current method includes four times of silvicultural treatments, and they last until 35 years after plantation. The costs for the treatments could not be recovered until after 100 years of plantation. Hence it is required to reduce the number as well as the age of the last application of silvicultural treatments. The results of simulation says that the rotation period becomes shorter if the discount rate increases. And it becomes longer if the price of carbon dioxide increases. It is well known that the rotation period lengthens if public values are added to the stands. It is also possible to find optimal management scheme, however, by adjusting the number and the age of silvicultural treatments. Consequently, it could not be an optimal method of forest management to apply long and flat rotation period even some public values are added, but it is required to adjust and apply various rotation period according to the treatment numbers and ages for each species. The current effort to protect forest fire does not satisfy optimal conditions. The social value of forest increases if we put more efforts on fire protection. Consequently it is necessary to extend the efforts on fire protection by increasing the government budget.

Researchers: Sang-Min Lee; Kyeong-Duk Kim and Seong-Hwan Song E-mail address: smlee@krei.re.kr