Many types of wind-exposed plant communities occur in the alpine zone of Mt. Chogatake in the Japanese Alps, each type being related to the lithology of the site of occurrence. A study was made of the development, coarseness and stability of the slopes of the alpine zone in an attempt to elucidate the formative conditions of these plant communities.
The relation between the variance and the mean of individual size in a population is important for understanding population structure. Using monocultures of Larix leptolepis, we examined the relations between the variance and the mean of individual weight with reference to population growth and density. The variance of individual weight increased with an increase of the mean in accordance with an empirical equation consisting of the power equation of the mean. Properties of the coefficients in the equation were discussed briefly.
At higher elevations on Mt. Asakusa, one of the mountains characterized by deep snow accumulation in Japan, the relationship between snow depth and the distribution pattern of plant communities was studied in connection with topographical conditions. Dwarfed Fagus crenata forests in the northwestern〜western part (N〜W slope), and scrubs and meadows in the southern〜eastern part(S〜E slope). The snow depth in meadows was the deepest among the four plant communities, and that in scrubs was deeper than those in Fagus crenata forests and dwarfed Fagus crenata communities. However, little difference in snow depth was found between Fagus crenata forests and dwarfed Fagus crenata communities. Therefore, it is difficult to explain the distribution of plant communities only by the snow depth. It is presumed that topographical conditions affect not only the distribution of snow depth but also the effects of the snow on plants, and that consequently the distribution pattern of plant communities is determined through the influence of the topography.
Observations on the shoot-population in M. sinensis patches were made in order to describe and analyse the course of growth of those patches. A simple logistic formula was applicable to a description of the yearly increasing course in standing shoot-numbers in each month from winter to early summer. Also, a logarithmic difference equation was applied to the description of the course of increase for each of the shoot-populations of the other months. The logistic equations tracing patch growth in different habitats were given by changing the parameter-a of the logistic one for the patches in Shizuoka City. Requisite times for reaching 95% of the maximal shoot-numbers(the parameter-Nmax)were computed by those equations. The requisite time appeared to be very sensitive to the parameter-a related to the tillering times of a patch.
Time budgets and home range utilization of the brown dipper were investigated in central Kyushu from 1982 to 1985. The dippers preferred shallows mainly for foraging but avoided pools. Both sexes utilized the same parts of the territory during the breeding season. Foraging for themselves occupied 20-50%, and resting including preening occupied 20-50% of daytime activity throughout the year. A large amount of loafing time and small foraging time may be an adaptation to the temporally adverse food condition owing to spates. Foraging activity when they were feeding young occupied up to 60-80% of daytime activity. Energy expenditure was high during the nest building and rearing stages and low during the incubation stage. Only females incubated eggs and brooded young, but both sexes contributed equally to nest building and feeding of young. A large expenditure of time and energy for nest building and feeding of young may be one of the reasons why the brown dipper maintains a monogamous mating system.
The train millipedes, Parafontaria laminata group, are endemic in Central Japan and notorious for stopping trains during their outbreaks. Recently, it was established that the train millipede contains 3 species and 1 subspecies (P. laminata laminata ATTEMS, P. laminata armigera VERHOEFF, P. kuhlgatzi VERHOEFF and P. echizenensis SHINOHARA). The distribution of each species is restricted to a certain locality. P. laminata armigera is distributed in the mountainous region of Central Japan. Outbreaks occurred in autumn, at 8 year intervals, or in both 7th and 8th years in this region. The outbreak population consisted mainly of adults, but also 7th instars at times. The adult P. l. armigera laid eggs early in the next summer and died. The eggs hatched in the summer and the 1st instar larvae hibernated in the winter without molting. The larvae lived in the soil, molted once a year, and became adults after the 7th molt. The adults and some 7th instars swarmed on the soil surface in autumn, which was regarded as the outbreak. The swarming records of the other train millipedes were arranged according to the locality, although the periodicity of the outbreak is not clear.
The current status and research efforts on forest decline in Central Europe, possibly affected by deposition of atmospheric air pollutants, are reported. Information is drawn from recent review articles and the author's observation and personal communications during Excursion No. 13 of the XIV International Botanical Congress in Summer 1987. The forest decline is intensifying and spreading rapidly throughout Central Europe. In most cases, Picea abies trees at altitudes between 700-1300m show damage symptoms, such as yellowing and early loss of needles, loss of fine roots, and decreased growth, leading to premature deaths. The combination of symptoms and degree of damage to the forest trees varies greatly among sites as well as the suspected causes including soil acidification, ozon injury, and climatic stresses. An increasing number of researchers agree that multiple stress factors. both natural and anthropogenic, predispose trees to damages, Strong disagreements exist over whether or not the deposition of atmospheric pollutants(acid rain)is the common primary cause for the widespread forest decline. For an objective evaluation of different hypotheses, standardization of data collections, as well as more active exchange of opinions and research techniques among different research techniques among different research groups within and among nations is necessary.