|| 要旨トップ | 目次 |||日本生態学会第59回全国大会 (2012年3月，大津) 講演要旨
一般講演（ポスター発表） P3-024A (Poster presentation)
In the Tanzawa Mountains located in the Kanagawa Prefecture, Japan, the decline of beech forests has been observed since 1980. Various studies were conducted thereafter, and O3 and water shortage in addition to beech sawfly, were suspected of the decline factors. We examined the ecophysiological characteristics of beech seedlings using environment-controlled cabinets, to clarify the acute and chronic effects of O3 and water stress singly or combined on this species. The seedlings were exposed to 70, 50 or 0 ppb O3 with different water treatment such as 1200, 840 or 600 mm in terms of growing period precipitation, and harvested after 12 weeks. With increasing O3 concentration or water stress, the dry weights were decreased, while the NAR similar to the RGR showed a decreasing tendency to O3 concentration or water stress. However, effect of water stress on 70ppb O3 treated seedlings and that of O3 concentration on 600 mm treated seedlings were ambiguous. In the present experiment, some ecophysiological activities and biomass production were reduced with increasing concentration of O3 and with increasing water stress, while these two factors acted additively from the statistical analysis, which was strongly suggested that O3 and water shortage induced the observed decline of beech forests in the Tanzawa Mountains.