Effects of thinning and mixing canopy tree species on species diversity of forest plants in cool temperate Satoyama area

日本的许多林区都被废弃的矮林和人工针叶林所占据。未受林业活动影响的天然林仅限于小面积。由于短时间内多次采伐干扰了林分的演替过程，使得弃耕萌生林和人工针叶林的森林结构相对单一。因此，在废弃的矮林和人工针叶林中，由不同更新阶段组成的异质镶嵌结构已经消失。本项目研究了不同林冠条件和森林经营对冷温带典型森林植物物种多样性的影响。本研究以日本中部新泻县上川村为研究对象，在第一章中，对废弃矮林地区潜在的植物物种多样性进行了估算。第二章研究了不同林冠条件对人工柳杉林、针阔混交林和废弃矮林地被层光环境和植物物种多样性的影响。揭示了不同林冠条件下各林型植物种的功能团。第三章对森林植物物种保护的森林经营体系进行了研究。第四章研究了人工林林隙中阔叶树种的更新情况，在人工林隙建立后，连续三年进行更新调查。在每一节中，讨论了恢复里山地区森林植物物种多样性的管理方法。

A lot of forest areas in Japan have been dominated by abandoned coppice and artificial coniferous forests. Natural forests which have not been affected by forestry activity are restricted to small areas. Forest structure in the abandoned coppice forests and artificial coniferous forests is relatively homogeneous due to interruption of succession by repeated cutting in a short period. Therefore heterogeneous mosaic structure which is comprised of various regeneration phases has been disappeared in the abandoned coppice and artificial coniferous forests.This project examined how different canopy conditions and forest management affected specie diversity of forest plants in representative forests of cool temperate zone. The study of this project is conducted in Kamikawa village, Niigata Prefecture, central Japan.In the first chapter, potential plant species diversity was estimated in the abandoned coppice forest areas. In the second chapter, the effect of different canopy condition on light environment of forest floor and plant species diversity was examined in artificial Japanese cedar forests, broadleaf-conifer mixed forests and abandoned coppice forests. The guilds of plant species in each forest type with different canopy conditions were revealed. In the third chapter, forest management system conserving forest plant species was examined. In the forth chapter, regeneration of broad-leaf tree species in artificial canopy gaps was investigated after successive three years after creating the gaps. In each section, management method which restores the species diversity of forest plants in Satoyama area was discussed.