The flora and ecology of bryophytes and the changes over two decades was studied in Chiba City and Yotsukaidou City, Chiba Prefecture. The study area consisted of seven sites representative of various urban and natural environments; nature park, agricultural area, urban park, street residential district, housing complex district, commercial district and industrial district. The total number of bryophytes species in the study area in 1975 identified 83 bryophytes species, in 1995, 78 species was recorded. The total number of bryophytes species decreased during the two decades, but the number of species at each individual site increased for most sites. Agricultural district was the only site in which the number of species decreased. Species of erect forms increased at all sites, while prostrate forms decreased sharply at the nature park and agricultural district sites. Thalloid form increased greatly at the nature park site. Erect forms remained the only type found in the industrial district site. The most commonly encounted substrata for both years was soil, followed by tree trunk in 1975 and by concrete in 1995. Four species groups were recognized. Group 1 occurred at all sites from rural to heavily urbanized area. Group 2 found from rural to moderately urbanized areas. Group 3 occurred mainly in rural areas. Group 4 restricted to natural and rural areas. A positive correlation was observed between woody vegetation cover area and number of bryophytes species. The results suggest that bryophytes are useful as bioindicators to help understand environmental changes due to urbanization.

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The relationship between climatic conditions and the distribution of Dichelyma japonicum was investigated in Niigata Prefecture and its adjacent regions, central Japan. This species is frequently distributed in the interior mountainous areas where there is deep snow in winter. It grows on shrubs beside ponds or streams, where high air humidity persists at snow-free times of the year. In winter, deep snow covers the moss together with host shrubs. The distribution of this moss is restricted to within wet areas where there is deep snow in winter and higher precipitation in summer. It is probably excluded from the highest altitudes and high latitudes, due to late sporophyte maturation.

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Spores of Riccia fluitans L. were reported on the basis of a plant collected at Hamasaka-cho, Hyogo Prefecture, central Japan. Judging from its choromosome number(n=8) and ventral scales, which were arranged in one row, this plant was R. fluitans sense strict.

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The polysety of Pogonatum fastigiatum Mitt., Rhodobryum ontariense (Kindb.) Kindb., Mnium spinosum (Voit) Schwaegr. and Rhizomnium magnifolium (Horik.) T. Kop. was studied based on the Chinese materials. In Pogonatum fastigiatum, over 90 % of the fertile shoots were monosetous, though one shoot with three setae was present. In Rhodobryum ontariense, the number of setae in a shoot varied from one to five, and one appears to be the most common. Very few shoots had more than three setae. In Mnium spinosum, about 80 % of the fertile shoots were polysetous. More than two setae were found on about 50 % of the shoots. In Rhizomnium magnifolium, the number of setae in a shoot varied from one to four, and one appears to be the most common. The population from Sichuan Province showed a higher degree of polysety than that of Yunnan Province.

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