The potential of hinoki (Chamaecyparis obtusa [Sieb. et Zucc.] Endlicher) plantation forests for the restoration of the original plant community in Japan

We estimated the potential of plantation forests for the restoration of the original plant community. We compared the understory vegetation in hinoki (Chamaecyparis obtusa [Sieb. et Zucc.] Endlicher) plantations at the understory re-initiation stage and in adjacent natural forests. To estimate the effect of the original natural forests on the understory species composition of plantation forests, we established study sites in five types of natural forests (mature evergreen broadleaf, mature deciduous broadleaf, mature evergreen coniferous, immature deciduous broadleaf warm-temperate, and immature deciduous broadleaf cool-temperate) and nearby plantation forests. The understory vegetation of the plantation forests had a higher species richness, a higher proportion of early-seral species, and a higher proportion of herb or fern species than the natural forests. The differences between natural and plantation forests varied according to the species composition of the natural forests. The composition of the understory vegetation of the plantations at the understory re-initiation stage was similar to that of the immature deciduous forests. The characteristics of immature, disturbed forests remained in the understory vegetation of the hinoki forests. No great loss of species was observed. Our findings suggest that most of the original forest species still survive in the understory of the plantation forests. These forests have the potential to follow the successional pathway to broadleaf or mixed forests via thinning or clear-cutting without planting.     

The effects of clearcuts and forest buffer size on post-breeding emigration of adult wood frogs (Lithobates sylvaticus)

The establishment of terrestrial buffer zones around vernal pools has been recommended to provide upland habitat for pool-breeding amphibians in areas where forestry practices occur adjacent to breeding sites. However, few studies have empirically tested the effectiveness of buffers. We assessed post-breeding emigration behavior (net emigration distance, rate of movement, proportionate use of available habitats) of radio-tagged adult wood frogs (Lithobates sylvaticus) at nine vernal pools with experimental forest buffer treatments in central Maine, USA. Buffer treatments were either 30-m (N = 3) or 100-m (N = 3) forest buffers surrounded by a 100-m wide clearcut; pools surrounded by uncut forest served as reference sites (N = 3). We tracked 33 individuals in 2004 and 2005, for an average of 41 days, as they emigrated from breeding pools. Recently clearcut habitat was permeable to emigrating adult wood frogs, particularly females. A higher proportion of frogs at 30-m buffer sites than at 100-m buffer sites traveled through the clearcuts to reach intact forest beyond, suggesting that 30-m buffers may not provide sufficient upland habitat to support adult wood frog populations. There was high variability in emigration behavior among frogs, regardless of buffer treatment, and males and females tended to exhibit differential responses to different buffer sizes and to clearcut habitat. Although wood frogs in this study utilized both 30-m and 100-m forest buffers, variability between sexes and density-dependent effects could render small buffers (e.g., 30 m or less) inadequate to support these populations.