Abandonment of coppicing in secondary forests is thought to be one of the major causes of the recent decrease in plant species diversity in man-made landscapes.　Resuming traditional forest floor management has been attempted for conservation purposes elsewhere in Japan.　In recent years, cutting of evergreen trees invading and grown below shrub layer has also been attempted.　There are few reports that the effect of the management of forest understory was evaluated by the plant functional groups.　We examined the effect of management on plant diversity of the herb layer by comparing four management treatments:mowing understory and removing tree leaf litter （MR）, mowing understory （M）, cutting evergreen trees below the shrub layer （C）, and abandonment （A）.　Study sites were located in Quercus serrata secondary forests in the northern part of Musashino terrace, south-eastern Kanto district, Japan.　We recorded plant species occurrence and coverage in 90 plots （8×8m）, and compared species richness and the Shannon diversity index.　We classified species into seven plant functional groups （PFGs） using results of cluster analysis for nine functional traits of plants occurring in the herb layer.　We compared functional diversity and composition among the management types using CCA （Canonical Correspondence Analysis）.　Species richness, Shannon diversity index, and functional diversity of the herb layer were the highest in MR.　Effect of management treatments was stronger on PFGs composition than on species composition.　Some PFGs showed biased appearances in specific management types.　The species richness of four PFGs:PFG2 that included crowding grasses blooming in spring, pollinated by wind, fruiting in autumn, and dispersed by gravity;PFG5 that included deciduous herbs fruiting in autumn and dispersed by wind;PFG6 that included herbs blooming in spring and pollinated by insects;and PFG7 that included deciduous herbs blooming in summer or autumn and fruiting in autumn were high in MR and M.　As many threatened species were present in PFG2, PFG5, and PFG6 and many ruderal species were present in PFG7, we concluded that it was important to conserve plant species of PFG2, PFG5, and PFG6 by mowing and removing tree leaf litter as the preferred vegetation management practice for preserving biodiversity in coppice forests.　This study clarified that evaluating by functional composition reflects the influence of forest floor management rather than species composition in secondary forests.

Yakushima, Kuroshima, Kuchinoshima, and Nakanoshima Island are located between Kyushu Island and the Amami Islands in southern Japan.　Natural evergreen broad-leaved forests dominated by Castanopsis sieboldii are distributed on these islands.　The aim of this study was to examine the differences in species composition and richness among these forests and identify the influencing factors.　Fifty-six stands of forests on the four islands were investigated.　Species composition of the stands was analyzed using the phytosociological tabulation method.　The stands were divided into four types, A, B, C, and D, which were distributed on Yakushima, Nakanoshima, Kuroshima, and Kuchinoshima Island, respectively.　The results of the detrended correspondence analysis showed that the species composition differed among the four stand types and that the difference between type A and the other three stand types was relatively high.　Species richness （number of species per 100 m²） of type A stand was significantly higher than that of the other three stand types.　Several species found in type A stand were not observed in Kuroshima, Kuchinoshima, and Nakanoshima Island.　The differences in species composition and richness between type A and the other three stand types reflect to some extent the difference in flora between Yakushima Island and the other three islands.　Furthermore, the distance from the nearest coastline to type A stand was considerably longer than that to the other three stand types, suggesting that the sea breeze conditions differed considerably between type A and the other three stand types.　Additionally, an analysis using the general linear model showed that the sea breeze conditions significantly affected the species composition and richness of the stands.　Taken together, these findings indicate that the flora and sea breeze conditions were the main factors influencing the species composition and richness of natural evergreen broad-leaved forests dominated by C. sieboldii on the four islands.

We monitored the deer grazing pressure on a population of an unpalatable perennial, Primula japonica in a long-term grazed habitat by sika deer, using an enclosure treatment with cages for two years. The two-year census showed that all unenclosed individuals of this species lost their aboveground parts due to grazing, whereas all enclosed individuals survived and most of them elongated inflorescences at the end of the census period.　Although inflorescences extended outside cages, no grazing on the reproductive organs was observed. We also quantified the main chemical compound of the species using the gas chromatography and evaluated variations in the concentration of the compound among regions (a high deer-density site and a low deer-density site) and among organs (leaves and inflorescences), which identified flavone as the main compound and detected a higher flavone concentration in flowers than in leaves but little difference among regions. Although the results showed a possibility that flavone can contribute to protecting reproductive organs from deer grazing, we could not demonstrate clear evidence that flavone has toxic effects on deer. Future studies need to evaluate whether deer also graze other unpalatable plants in high-deer density regions and to verify mechanisms on how sika deer can overcome the chemical defence of unpalatable plants.

Changes in vegetation were investigated for three years in a newly constructed and afforested coastal area that had been disturbed by the tsunami caused by the Great East Japan Earthquake. The maximum vegetation coverage was less than 20% throughout the study period. A total of 62 species appeared during the study period with 25 （40.3%） of them appearing continuously, while the occurrence of the other 37 species changed from year to year. Few new invasions were among the few woody species and coastal species that occurred during the survey period. The number of alien plants accounted for per year was 30-40% of the total number of species. Successional trends in vegetation, such as an increase in perennial species, were not observed clearly.　Successional change was slow compared to that of the natural coastal forests that were disturbed by the tsunami, probably due to low water permeability of soil and poor seed sources caused by land reclamation using sand collected from sediments from nearby hills. A more comprehensive survey is needed to understand the impact of the subsequent large-scale restoration/reconstruction of infrastructure on coastal vegetation after tsunami disasters.

Viola grayi Franch. et Sav. is a threatened coastal dune plant endemic to Japan.　We examined the distribution of V. grayi along shoreline-inland gradients of sandy coastal areas to improve our understanding of the habitat traits of this threatened violet.　A belt-transect survey was conducted in seven study sites, and relationships between the spatial arrangement of vegetation zones and the distribution of V. grayi along shoreline-inland gradients were illustrated.　The dune vegetation consisted, in the following order from the shore to inland, of a tidal drift zone, herb zone, dwarf shrub zone, and shrub zone.　Viola grayi was found mainly on the inland part of the herb zone and the dwarf shrub zone.　In most cases, the habitat width of V. grayi was narrower than that of major dominant dune plants such as Calystegia soldanella, Carex kobomugi, Glehnia littoralis, and Vitex rotundifolia. These results suggest that preventing the reduction of beach-dune areas is important for the conservation of V. grayi.