Analysis of species and genetic diversities' dynamics in natural forest management.

东京大学农学部大学森林研究所在北海道的大学森林研究所实施的天然林的可持续经营体系--大规模择伐，被认为是可持续木材生产的保证。然而，目前对这种经营方式下天然林物种多样性和遗传多样性变化的研究还很少。然后对天然林择伐利用中存在的问题进行了整理，并从物种多样性的角度进行了讨论。以高山冷杉林为例，探讨了择伐的遗传效应。研究结果表明：（1）天然林的择伐改变了林分结构，尤其是林木直径结构。因此，有必要对阔叶树种进行采伐，以维持森林的物种多样性。2)选择伐降低了高山冷杉天然林中同质等位基因组合的比例，增加了异质等位基因组合的比例。但等位基因频率在人群中没有显著变化。3)不同海拔高山冷杉种群间存在遗传分化。在北海道的大学森林里的大六先生。

It is thought that sustainable wood product is secured by the extensive selection cutting which is a sustainable management system of natural forest conducted in University Forest in Hokkaido, The University Forests, Faculty of Agriculture, The University of Tokyo. However there is little research on the changes in species diversity and genetic diversity of the natural forest where this management was conducted. Then we put the problems in the utilization of natural forest by the extensive selection cutting in order and discussed on them from the viewpoint of species diversity. We discussed on the genetic effect of selection cutting of Abies sachalinensis forest as an practical sample. And we also revealed the actual genetic diversity of Abies sachalinensis forests in the University Forest in Hokkaido.Following results were obtained by this research ; 1) Forest structure, especially in diameter of trees, had been changing by the selection cutting in the natural forest. Then it seemed to be necessary to cut broad-leaved species to maintain the species diversity of the forest. 2) Percentage of homogeneous allele combinations was decreased and heterogeneous allele combinations were increase in the natural stand of Abies sachalinensis by the selection cutting. However there was not significant change in allele frequencies in the population. 3) Genetic differentiation was detected among Abies sachalinensis populations distributed a different altitude on Mt. Tairoku-san in University Forest in Hokkaido.