Two spring-head plant communities, the Montia fontana community and the Rumex gmelinii community, were newly recognized in the border area between Kushiro Mire and the surrounding hills. Species composition (1 m×1 m) and habitat character were recorded, and compared to other plant communities which were previously reported. Ground surface profiles were also recorded in one typical habitat. Montia fontana and R. gmelinii were predominant in each plant community, and a few other plant species (1-10, 6-13, respectively) accompanied them. The M. fontana community and the R. gmelinii community were concluded to belong to Angelico-genuflexae-Cardaminion Ohba 1975, because they have Cardamine regeliana and Angelica genuflexa which are character species of Angelico-genuflexae-Cardaminion Ohba 1975. The R. gmelinii community was distinguished from Rumeco-Calthetum palustris var. enkoso Ko. Ito et Matsuda 1992 by the existence of Cardamine regeliana and A. genuflexa, and by the absence of Phalaris arundinacea, Impatiens textori and Carex rhynchophysa. The M. fontana community and the R. gmelinii community represented different springhead habitats. The former existed on sandy flats that are widely soaked with shallow flowing spring water, while the latter existed on muddy gentle slopes into which spring water seeps. The difference in habitats of these two plant communities seemed to be caused by the height gap between the spring-head and the bottom flat. The gap was small in the M. fontana community and relatively large in the R. gmeliii community.

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The establishment of a Japanese alder （Alnus japonica） forest was studied at the northwestern coast of Lake Utonai, located in the southern area of Ishikari Depression, and its causal factors were examined. To assess its topographical features, we established five lines of length 230-320 m that extended from the lakeshore to the inland mesic forest. A 5 m wide transect was also set up along each line to determine the size and age structure of the Japanese alders. The ground level of the inland mesic forest on the Holocene terrace was approximately 0.5 m higher than that of the coastal plain that was covered by the alder forest. On the coastal plain, the alder forest had replaced the large parts of the fen meadow that had been widely distributed in the 1970s. The alder forest is characterized by canopy trees of relatively uniform diameter within the range of 20–30 cm, and abundant small stems of sprouts originating from underneath the canopy. However, no seedlings and saplings of the Japanese alder grew in the forest and the remaining fen meadow. The ages of the canopy alder trees converged into a narrow range, from 55 to 25 years, irrespective of tree forms; single stem or multistem originating from sprouts. The duration of the mass establishment of Japanese alder trees corresponded well with the period of the major land development, including road and river improvements conducted by the national government.　Thus, the lowering of the water level or draining of Lake Utonai that was caused by the land development resulted in the creation of a suitable site for the seed germination of the Japanese alder, which in turn facilitated in the establishment of the alder forest. In conclusion, the expansion of the alder forest has already ceased in the study area.

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Cryptomeria japonica plantations with developed understory (shrub and herb layers) in the lowland parts of Yakushima Island were surveyed to examine their potential function providing habitats for lucidophyllous forest elements. In analysis, the species composition and species richness (the number of species per 100-m² plot) of C. japonica plantations, secondary lucidophyllous forests, and primeval lucidophyllous forests were compared to clarify the differences in those attributes among the forest types. The results showed that species composition differed among the forest types: with respect to lucidophyllous forest elements, C. japonica plantations were mainly characterized by the luxuriance of terrestrial pteridophytes and the scarcity of evergreen trees and evergreen shrubs in comparison with secondary lucidophyllous forests and primeval lucidophyllous forests. Lack of epiphytic pteridophytes is also significant in C. japonica plantations compared with primeval lucidophyllous forests. Species richness was lower in C. japonica plantations than in primeval lucidophyllous forests with respect to lucidophyllous forest elements, while the attribute was similar between C. japonica plantations and secondary lucidophyllous forests. The ratio of the number of lucidophyllous forest elements showing higher occurrence frequency to the total number of lucidophyllous forest elements was similar between C. japonica plantations and lucidophyllous forests. Meanwhile, most of lucidophyllous forest elements showing lower occurrence frequency in lucidophyllous forests also indicated lower occurrence frequency in C. japonica plantations. These findings suggest that, although C. japonica plantations are capable of functioning as habitats for lucidophyllous forest elements to some degree, it is unreasonable to expect the plantations to facilitate the establishment of all types of lucidophyllous forest elements.

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We investigated the effect of shifting the frequency and timing of mowing a grass embankment of the Tama River that was dominated by Festuca arundinacea over a nine year period in Akiruno City, Tokyo. Mowing frequency was shifted from three or four times a year to twice a year (i.e. in spring and autumn). The spring mow was done in March when only wintergreen F. arundinacea was dominant and almost all of the native species had not yet emerged. Changing the frequency of mowing resulted in a decrease in F. arundinacea coverage. In the ninth year, F. arundinacea disappeared in more than half of the quadrats and the coverage decreased to less than 1%. Conversely, the coverage of Miscanthus sinensis increased gradually over the same period.The reduction in F. arundinacea coverage was attributed directly to mowing in spring, and indirectly to an increase in the dominance of native plants through competition. The results showed that changes in the timing and frequency of mowing was effective for reducing F. arundinacea.

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An artificial lucidophyllous (evergreen broad-leaved) forest dominated by planted Cinnamomum camphora is located in the urban area of Nishinomiya City, Hyogo Prefecture. Afforestation occurred several hundred years ago, and the forest has been conserved as a shrine forest of the Nishinomiya Shrine. We surveyed the flora and vegetation of this artificial forest to assess its species composition. We observed 37 late-successional species distributed across the forest. This species number was much lower than that calculated using two formulae for species-area relationship reported in a study of natural lucidophyllous forests in the southeastern area of Hyogo Prefecture. In addition, species composition was very different between the artificial and natural forests, with many late-successional species not seen in the artificial forest. These results indicate that the artificial forest of the Nishinomiya Shrine has a much simpler species composition than do natural lucidophyllous forests.

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