A 370-year dendroecological history of an old-growth Abies-Acer-Quercus forest in Hokkaido, northern Japan

Dendroecological techniques were used to study the dynamics and species rec ruitment patterns, spanning nearly four centuries, for a mesic, montane, ol d-growth forest in Hokkaido, northern Japan. The forest is dominated by Abi es sachalinensis (Masters), Acer palmatum (Thunb.), Quercus mongolica var. grosseserrata (Rehd.), and Cercidiphyllum japonicum (Sieb.). From 1620 to 1 750 and 1820 to 1840, Q. mongolica exhibited continuous recruitment into th e overstory. A lack of recruitment for all tree species from 1750 to 1820 f ollowed a 1739 volcanic eruption 200 km from the study area. Release events for individual trees occurred almost every decade of the stand history, in dicating that frequent small-scale disturbances coupled with infrequent lar ge-scale disturbances, impact tree growth and species recruitment. From 187 0 to 1950, canopy recruitment of Abies and Acer dominated the forest, while recruitment of Quercus ceased. These later successional species appeared t o be replacing Quercus, suggesting that the syndrome of declining oak domin ance is an increasingly global phenomenon. However, successional patterns i n the forest are difficult to predict because intensive deer browsing has r ecently prevented canopy recruitment of all tree species and the possibilit y of future large-scale disturbances, such as fire and volcanic eruption.