Effects of habitat selection of wood mice on the diversity of canopy tree species in mixed forests.

本研究的目的是阐明混交林中林鼠、树种和苗木捕食者的栖息地选择对树冠树种多样性的影响。检验了三个工作假说：1.混交林中，由于林冠结构和树种决定了林地地面光照强度的不均一性，林下草本植被盖度因林冠层的开阔而改变，并构成了木鼠的栖息地，构成了各种斑块2：木鼠(Apodemus orosus和A.argenteus)的栖息地选择随季节变化，但成熟山毛榉(Fagus Crenata)林和日本柳杉(Cryptomeria Japan Onica)人工林都选择了密度较大的草本斑块。3：由于林鼠活动开阔地低于封闭地，木鼠种子捕食压力随树冠结构的变化而不是随种子密度的变化而变化，混交林具有多样性的物种组成和林分结构。林分结构特别是草本结构改变了木鼠的种类组成、种群密度和活动能力。从这些结果来看，通过控制林鼠捕食种子和苗木的压力来改变森林更新过程为集约化管理草本植被结构是可能的。因此，林冠层的集约管理可能会导致森林生态系统的生物多样性管理。

Aim of this study is to clarify the effects of the habitat selection of wood mice, tree seed and seedling predator, on the species diversity of canopy trees in mixed forests. Three working hypothesizes were inspected.1:In the mixed forest, because of heterogeneity of light intensity on the forest floor, which determined by the canopy structure and tree species, herbaceous vegetation coverage of under growth was changed by the openness of canopy layer and constructs the habitats of wood mice that comprise the various patches2:Wood mice(Apodemus speciosus and A. argenteus) habitat selection was changed seasonally, but selects the dense herbaceous patch both in mature beech (Fagus crenata) forests and a sugi (Cryptomeria japonica) plantation.3:As wood mice activity of the open site was low than that of the close site, wood mice seed predation presser was changed depend on the crown structure not on the seed density.Mixed forests had variety of species composition and stand structure. Wood mice species composition, population density and activity were changed by the stand structure, especially by the herbaceous structure. From the these results, it will be possible to change the forest regeneration process through the control the presser of seed and seedling predation by wood mice to intensive management for herbaceous vegetation structure. And in consequence intensive management of canopy layer may result in the bio-diversity management in forested ecosystems.