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Questions In many places worldwide, dune vegetation has rapidly declined owing to the expansion of various land uses, which pose a serious threat to many native dune plant species. A better understanding of species–area relationships in coastal sandy patches (i.e., beaches and dunes) is valuable for designing effective management strategies for the conservation of beach–dune flora in coastal regions. We investigated how the area and other attributes of sandy patches affect the number of species (dune, inland, and alien species) and whether the occurrence of all dune species is area‐dependent. Location Sandy coast of San'in Kaigan National Park, western Japan. Methods All vascular plants at 43 sites (sandy patches) were recorded. Using generalized linear models, we analyzed the relationships of the area and other attributes of sandy patches with the number of species and the relationship between the area of sandy patches and the occurrence (presence/absence) of each dune species. Results Larger sandy patches maintained a greater number of dune species and harbored some nationally threatened ones. The number of inland and alien species also increased with an increasing area of sandy patches, although the effects of other size and site attributes varied; shoreline length, beach–dune height, and high openness of the beach were selected as important positive factors for the number of dune species. Furthermore, most dune species in herb and dwarf shrub zones were area‐dependent and tended to occur in larger sandy patches, whereas some species of the tidal drift zone, including locally threatened dune species, were area‐independent. Conclusions Effective conservation of beach–dune flora demands not only the protection of larger sandy patches but also the selective preservation of sandy patches with better developed dunes. Moreover, the maintenance of unstable habitats for area‐independent dune species is important.

：Miscanthus sinensis grasslands can be dominated by dwarf bamboo such as Pleioblastus chino var. viridis after abandonment, leading to decrease diversity in the communities. We investigated the effect of mowing on recovery of grassland species richness and cover, and overall species composition over three years. Two treatments were tested: mowing above ground vegetation every autumn and mowing above ground vegetation every autumn with selective cutting of P. chino var. viridis in the first summer. The number of grassland plant species increased slightly under both treatments, although M. sinensis did not return as the dominant species in either treatment after the restoration. The addition of selective cutting of P. chino var. viridis resulted in greater cover of M. sinensis and higher richness and cover of grassland species. These results show that selective cutting of P. chino var. viridis in summer enhance the effect of management for restoring grassland species diversity in long-abandoned semi-natural grassland communities.

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Premise In temperate sand dunes, rising air temperature from climate change could not only further elevate surface soil temperatures during summers, but also drastically change the range of soil temperatures in other seasons. Winter warming may shift the timing of seed germination of dune species that require cold stratification for dormancy release. Methods We assessed the effects of temperature on dormancy and germination of Viola grayi seeds and evaluated whether winter warming could affect its germination phenology by conducting germination experiments and analyzing soil temperature data in cold and warm winters. Results Viola grayi seeds were dormant when dispersed in spring. One‐month moist‐chilling treatment (4°C) effectively released dormancy, while short, intermittent lower temperatures (alternating 20°/5°C) did not. Continuous higher temperatures induced secondary dormancy in nondormant seeds. During a cold, snowy winter, the surface soil temperatures of the sand dune remained at 0°–2°C for approximately 1 month owing to the accumulated snow, while the period of such stable low soil temperatures was much shorter during a warm, less‐snowy winter, and the highest soil temperature reached 20°–25°C. These results suggest that dispersed seeds germinate in the following spring after winter chilling, but they may remain dormant after warm winters. Conclusions With winter warming, seed dormancy of V. grayi seeds could be prolonged and the associated germination delayed. Assessing the minimum requirements for dormancy release and the potential to form persistent soil seed banks is important for judging the necessity and urgency of conservation efforts for temperate dune species.