Fire and human impact on the vegetation of the western Tamba Highlands, Kyoto, Japan during the late Holocene

摘要

In the areas adjacent to Kyoto, an ancient capital of Japan, the regional vegetation is mostly secondary forest. In order to reconstruct the fire and vegetation history of the area and to estimate when and how the secondary forest was established, peat cores were obtained from a small basin in the western Tamba Highlands, 35-km northwest of Kyoto city. Pollen, plant macrofossil and charcoal records from the site indicate that the cool-temperate forest characterized by beech (Fagus crenata) with Japanese cedar (Cryptomeria japonica) developed in the middle Holocene (c. 4700-2400 cal BP). Forest fires were rare during this period. In the late Holocene, charcoal data indicate that at least two major fire events occurred. Following a fire c. 2500 cal BP, the vegetation changed from beech-dominated cool-temperate forest with Japanese cedar to a forest with less beech and increased pine. The next conspicuous fire took place at c. 900 cal BP, after which the vegetation shifted to a deciduous oak and pine-dominated forest, similar to the present vegetation around the site. The Gramineae pollen percentage was continuously high since the second fire event, suggesting that grassland was maintained. In the western Tamba Highlands, secondary forests were established during the eleventh century, but resource depletion was less serious and open secondary forest has been maintained by human activities.