2014 Volume 19 Issue 2 Pages 51-58
Species composition and biomass of shrubs was investigated at the forest floors of 8 stands suffered mass mortality caused by Oak wilt diseases at Shonai district in Yamagata. Another 8 stands without mass mortality were also investigated. All of these understories were covered with dense shrubs, while very few oak seedlings could be found. Relative light levels estimated by rPPFD at 0, 0.5 and 1.5 m above ground were approximately 2, 4 and 8%, respectively. Thus regeneration of oak trees seems to be difficult due to sever suppression by dense shrubs. Removing the shrubs from the forest floor would be effective to enhance seedling growth, because the rPPFD were significantly improved over 20% after the operation. Three kinds of the removed shrubs, i.e., Lindera umbellate, Clethra barbinervis and Camellia rusticana were chipped and given to cattle as feed. Even though the cattle did not prefer the shrubs very much, chips were available as feed. As is the case in pruning branch of the fruit tree, silage fermentation might improve the quality as feed of wood chips and may offer one option contributing to forest restoration and steady supply of food.
