2018 Volume 17 Issue 2 Pages 117-131
Understanding post-disturbance reforestation processes could make a valuable contribution towards predicting the impacts of future changes in disturbance regimes on forest ecosystems. In this study, we aimed to estimate biomass dynamics in a wave-regenerated fir forest following blowdown. Three research forest stands at different developmental stages (young, intermediate, and mature; 19, 36, and 59 years-old, respectively) were established in a wave-regenerated Abies forest on Mt. Shimagare in central Japan, where a severe large-scale windthrow event occurred during a typhoon landfall in 1959 (Typhoon “Vera”). For each stand, above- and below-ground biomass was estimated using tree census data measured repeatedly from 2001 to 2008 and size-mass allometric equations developed based on the sample trees’ data. Growth patterns were also examined by tree ring analysis. The estimated biomass was the lowest in the young stand, but reached a similar level in both intermediate and mature stands. During the research period, mean height and estimated mass of trees were increasing in all sites but plot biomass were not increasing in the mature site because of mortalities of canopy trees. In the intermediate stand, tree ring analysis showed that post-typhoon seedlings could grow fast and thus a similar biomass accumulated to that in the mature stand, where trees originated from advanced seedlings that existed in high density prior to the disturbance. Compared to mature wave-regenerated fir forest without disturbance, mature forest in this study had lower biomass and the onset of mortality started earlier. These results suggest that typhoon disturbance affect subsequent forest structures and biomass accumulation.
