Developing methods for estimating forest areas under article 3.4 of the Kyoto Protocol: A case study on private lands in Gifu prefecture, Japan

This study aims to develop a methodology to account for and identify forests under Article 3.4 of the Kyoto Protocol (forests under Art. 3.4), and then to calculate forest area under Art. 3.4. Forests under Art. 3.4 can be defined as "forests receiving silvicultural practices such as planting, weeding, pruning, pre-commercial thinning, and commercial thinning from 1990." Two approaches can be considered to calculate forest area under Art. 3.4 by using 1) the forest register and 2) practice records of the private plantations in Gifu Prefecture, Japan. As a result, we found that practice records were more suitable than the forest register for calculating the forest area under Art. 3.4. However, it might be possible to use both types of data, depending on their purpose and/or availability, since there were no significant differences between the two data sets. In addition, the two approaches together suggested that the forest area under Art. 3.4 covered approximately half of the plantations in the period 1990 to 2000.