open access

https://hdl.handle.net/2115/22091

Shifting mosaic in maintaining diversity of floodplain tree species in the northern temperate zone of Japan

英語

Rekifune River

2007-03-30

Elsevier B.V.

Forest Ecology and Management

241(1-3)

28-38

We examined the relationships between floodplain forest structure and disturbance frequencies in bar-braided and incised-meandering channel sections of the Rekifune River, northern Japan. This was undertaken with special reference to the life history traits at seedling and reproductively mature stages of eight dominant species (Chosenia arbutifolia, Populus maximowiczii, Toisusu urbaniana, Salix sachalinensis, Salix pet-susu, Alnus hirsuta, Ulmus japonica, and Fraxinus mandshurica var. japonica). These species were generally arranged along the flood frequency and intensity gradient represented by five geomorphic surface types: gravel bar, lower and upper floodplain, secondary channel, and terrace. However, habitat separation between seedlings and conspecific mature stands occurred with geomorphic surface type in four of the eight species, suggesting that these species require more than one geomorphic surface type to complete their life cycles. Comparisons of stand-replacement disturbances between the bar-braided and incised-meandering rivers suggested that the shifting mosaic pattern in association with the evolution of land surfaces plays a vital role in maintaining variety in regeneration habitats and development of riparian forests in a half-century time scale. We conclude that the key factors maintaining the diversity of floodplain tree species in the studied northern temperate forests are: (1) the development of diverse geomorphic surfaces providing regeneration and habitat niches, and (2) the timing of maturation and lifespan of early and mid-successional species consistent with the disturbance frequency.

学術雑誌論文

Accepted Manuscript

0378-1127