兵庫県南東部における照葉樹林の樹林面積と種多様性,種組成の関係

抄録

We investigated 29 fragmented lucidophyllous forests preserved in the precincts of shrines and temples in southeastern Hyogo Pref. to clarify species-area relationships. The correlation between the number of component species of lucidophyllous forest and the log of area was related by a highly significant linear regression. Area also showed a strong correlation with the number of micro-landform units and relative height of the forests. We classified the component species of lucidophyllous forest into (1) four species groups by the similarity of their distributional patterns along the areal gradient, (2) seven species groups by lifeforms, (3) six species groups by their tendency for occurrence in micro-landform units, (4) four species groups by the similarity of their occurrence probability for area and (5) four species groups by the similarity of their tolerance for human disturbance. In small forests, the species that prefered suitable soil moisture were absent due to the lack of mesic micro-landforms. The species with low occurrence in the biggest forest showed a tendency to be absent in smaller forests. The species whose occurrence was unaffected by the decrease of area were fairly common in secondary forests and distributed over a wide range of climatic, topographic and geographic conditions. Based on the species-area relationship, we proposed the necessary areas for conserving the lucidophyllous forest.