We examined the species composition of soil seed banks of Quercus serrata secondary forest by germination test, which was reserved in artificial banking covered with plastic sheet for 6 years. The seed density was 131.4 seeds/L and 52.7 species. The dominant species in the seed banks were Eurya japonica var. japonica, Mallotus japonicus, Solidago altissima, Hypericum laxum, Pseudognaphalium affine, Cyperus flaccidus and others, and these dominant species are common in the seed bank of Q. serrata forests. Compared to the species composition of the seed banks non-reserved and reserved for one year, the soil reserved for 6 years did not contain some species such as Alnus japonica and Erigeron philadelphicus. The seeds of these species would lose their germinability for 6 years, since the period of dormancy is different from species. Therefore, our forest topsoil reserved for 6 years could have ability for the material of revegetation, because the soil had as much as woody buried seeds as the common soil seed bank in Q. serrata forests, however, it is required to consider sufficiently that some species may lose their germinability.
In total, 3,310 fern communities established on hardscapes (hard landscape elements such as walls, stone walls, open areas between buildings, or roadside openings) in 60 urban areas in Chubu region, Honshu, Japan, were investigated to analyze the habitat preferences of each fern species and examine the impact of urbanization on the distribution of each species. The analysis was conducted using a strategy similar to that employed in a previous study conducted in Kinki and Chugoku regions. Results showed that the impact to presence/absence of each species by urbanization was confirmed in 19 species (52.7%). Almost all species that preferred open areas between buildings were forest species, those that preferred walls were epiphytic species, whereas stone wall habitats were preferred by various species, in particular those which were originally adapted to inhabiting cliffs and rocks. Stone walls could be important as urban secondary habitats for rock or cliff ferns, including epiphytic species. These sites may serve as habitats for rare/endangered species. The fern species that particularly preferred the stone wall habitat could be useful as urban revegetation material, such as for wall greenings. Although each type of hardscape has its own utilization value, stone walls, which provide urban habitats for many fern species, need to be repaired and renewed in appropriate ways from the viewpoint of urban biodiversity conservation.