環境科学院 植物生態学セミナー   2012-01-31 (Tue) 10:30
(Room: A809 )

Establishment patterns of native and non-native trees on an abandoned skislope

Tomoaki Yoshida
(Chairperson: ?? )

After the abandonment of skislopes that has been increased due to economic reasons in the worldwide, the restoration on skislopes is required for returning natural ecosystem. To detect the characteristics of tree regeneration that may assist forest restoration, tree establishment patterns were examined by tree census and tree-ring analysis on an abandoned skislope in Hokkaido, Japan. The skislope abandoned in 1999 was enclosed by native birch (Betula spp.) forests and non-native larch (Larix kaempferi) plantations. On the slope, the locations of trees were measured in three belt transects at three elevations in 2009 and the stem disks were sampled from the base. The dominant tree taxa were Larix and Betula on the skislope, showing that the revegetation was distorted . Although the ranges of ages did not differ between the two taxa, i.e., ranged from 2 to 15 on Larix and from 2 to 14 on Betula, the immigration patterns differed, i.e., Larix immigrated concurrently soon after the abandonment but Betula immigrated steadily. Larix tended to immigrate in areas where trees had not established but Betula did not show such pattern. Therefore, Larix established intensively on bareground or grassland where trees had not been established soon after the abandonment, but immigrated less thereafter. The diameter growth was faster on Larix than on Betula. The growths of both Larix and Betula were reduced by crowding. Betula reduced the growth with increasing distance from forests. These results suggest that the restriction of larch immigration soon after the skislope abandonment, in particular, on the central areas of skislopes, support steady immigration and growth of native trees.


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