Twenty-one Years Post-fire Succession in a Small Watershed on Etajima Island, Hiroshima Prefecture, Southwestern Japan 【Article】

This study was conducted in a small watershed in Etajima Island, southwestern Japan to ascertainspecies performance 21 years after the fire using the Braun-Blanquet's method. Five plots were laid outin the burnt area for the interpretation of succession taking the edaphic or topographic conditions into consideration. Two fern species, Gleichenia japonicaand Dicrapnopteris dichotoma, that grew from surviving subterranean organs a year after the fire helped much in the recovery of the vegetation. At theonset of succession, soil erosion was controlled and trees invasion prevented due to the rapid growth anddistribution of these ferns. Vegetation growth showed variations as could be gleaned from the length oftime when the shrub, sub tree and tree layers have pervaded the area. In 1996, the tree layer appeared ina NW-valley side slope (Plot 3) with Pinus densifloraenlarging its crown over other broad-leaved trees.Clethra barbinervis, on the other hand, started developing in the sub tree layer in the plot on valley bot-tom at lower slope (Plot 1), middle valley bottom slope (Plot 2), and NE-valley side slope (Plot 4) in1980, 1989, and 1985, respectively. In 1990, Pinus densifloradeveloped in NW-valley side slope (Plot3) and on the ridge plot (Plot 5). Shrub layer developed in all plots two years after the fire except theplot on the ridge (Plot 5) where shrub appeared after four years.