Ecological and growth characteristics of trees after resumption of management in  abandoned substitution forest in Japan

Since the 1950s, secondary (substitution) forests known as Satoyama woods have been abandoned due to changes in human lifestyle. The aim of this study was to investigate the relationships between human activity and substitution forests to better understand the traditional management required to prevent succession to evergreen forest. An objective was to identify the tree species, their numbers of trunks (NT), and the basal area (BA) (collectively, the stand density) in the woods today, half a century after people abandoned the substitution forests. Another goal was to compare, over a six-year period, the figures for total NT, BA, and the number of living, dead or fallen trunks between an abandoned substitution forest (a control plot) and a mown plot. NT decreased from 700 trunks/ha to 600 trunks/ha on the control, and from 600 trunks/ha to 400 trunks/ha on the mown plot at ground level over six years. The total BA increased annually on the control plot but decreased from 48m2/ha to 38m2/ha on the mown plot over six years. Many hydrophytes (Alnus japonica, etc.), Quercus serrata, and other trees species were found dead on the mown plots. All Quercus myrsinaefolia (evergreen trees) were still alive by the sixth year. These results demonstrate that the vegetation in these forests succeeded to Quercetum myrsinaefoliae, Tyoische Subass., which is therefore shown as the potential vegetation of succession over this timescale. If it is desired to maintain the traditional vegetation type, then the study suggests that it is necessary to manage the substitution forest. This is in order to prevent succession to evergreen forest and can be achieved by cutting Pleioblastus chino, climbing plants, and shade plants (evergreen trees).