Abstract
The survival of tree seedlings and the amount of dispersed and buried seeds were surveyed. Also, the possibility of plant recovery was discussed on the nearly bare site; which is the result of browsing and trampling by sika deer (Cervus nippon yezoensis) in the broad-leaved stands of Nakanoshima Island, Hokkaido. Tree seedlings disappeared by 70-90% in first twenty days of observation and by 90% within fifty days in all plots. Browsing was the most serious factor, causing more than 80% of seedling damage. The number of dispersed seeds was 238-5,820/m^2 and 21-394/m^2 in 1995 and 1996, respectively. The number of seed species was 11-22 and 7-19 in 1995 and 1996, respectively. A considerable number of viable buried seeds were found, 50-2,700/m^2, and they were composed of 8-20 plant species. Both dispersed and buried seeds contained a large percentage of woody plant species. The number of buried seeds, the number of species and the ratio of viable seeds varied among the study sites, and there were no clear differences between open sites and sites in which the deer were excluded by enclosures. Therefore, the trampling of the forest floor by sika deer did not greatly influence the survival of buried seeds. According to the results of this study, plant recovery is difficult under heavy use by sika deer, however, potential revegetation appears to be possible, for the present.
