Abstract
An experiment plot (1 ha) was established in the Yamanashi prefectural forest of Hokuto City on the east slope of Mts. Yatsugatake to preserve the endangered species Picea koyamae. Comparative observations of trees in the plot were carried out in 2005 and 2017. During this period, the alive stem number greatly decreased from 2,755 to 1,248, the basal area at breast height (BA) increased from 30.0 m2 to 31.4 m2, and the number of confirmed taxa decreased from 37 to 29. We guessed that the decreases in number of stems and number of c onfirmed taxa were due to damage by Cervus nippon. The number of mother trees of P. koyamae larger than 20 cm in diameter at breast height (DBH) slightly decreased from 42 to 36 due to the positive influence of bark guards attached in 2005. However, it of younger trees smaller than 20 cm in DBH decreased significantly from eight to two. We propose that propagation of seedlings is necessary due to the lack of successful saplings for its in situ conservation.
