The block count method was applied to serow (Capricornis crispus) populations, and its efficiency was examined in Wakinosawa Village, Aomori Prefecture, and Agatsuma-gun, Gunma Prefecture, in 1976 and 1977. Each count area covered about 200 ha and was divided about equally into the count units, which varied in size from about 5 to 50 ha at each count series. The number of serows counted increased as the unit size decreased. This relation was described as the n-s curve, a reversed S-shaped curve, with the upper asymptote in favorable visibility conditions such as unclosed coniferous stands and deciduous forests after defoliation. In low visbility conditions such as young-aged coniferous forests, densely grown sasa (dwarf bamboo) communities and summer full leaves, the n-s curve showed an incomplete shape, a reversed J-shaped curve. Using the n-s curve, it was concluded that the highest accuracy was obtained in the 5-ha unit and in 1.5-hour counts under conditions of usual visibility and also could be obtained in the 10-ha unit in two-hour counts under conditions of favorable visibility.
The effect of defoliation by the larvae of a swallowtail butterfly, Papilio xuthus, on the radial and height growth patterns of the host tree, Zanthoxylum ailanthoides, was investigated in a deforested area, Large differences in growth of the tree height were due to suppressions by other plant species at the experimental plots. Each tree was classified into three groups ("tall", "medium"and "short"trees) on the basis of the value of mean relative height (MRH), which was calculated according to its relative height to the surrounding plants. A correlation was observed between the value of MRH in each tree and the radius excluding the bark thickness at the ground level or shoot growth. Higher value of MRH means a "tall" tree which is not covered by other plants. Stem analysis showed that the highest growth rate of annual ring width increment of all trees was achieved within 4 or 5 years after germination. There was a significant time delay in germination between "tall" and "short" trees. Thus, "short" trees, which are suitable hosts of the butterfly larvae, existed in the deforested area only for several years after clear cutting. The females of the swallowtail butterfly concentrated their egg laying on the trees of low MRH. High larval densities did not necessarily cause the low ring width increment of the host tree. The radial and height growth patterns of the host trees are discussed with reference to the ephemerals of habitat suitability for P. xuthus.
Pieris rapae crucivora and P. napi nesis live in the same area and feed on the same plant in Sapporo, northern Japan. The sympatric relation of these two species was reconsidered spatiotemporally at the immature and adult stages. Though no segregation pattern was found at the adult stage, vertical segregation at the immature stage between the two species was found on a common food plant, Rorippa sylvestris. Origin of the vertcial segregation as being limited to the immature stage is discussed preliminarily.
The biota in the water-filled internode of live bamboos was periodically sampled for a year in Nagasaki, Japan. At least 40 species of Metazoa were collected. The larva of a Dasyhelea KIEFER species (Ceratopogonidae), and that of Culicidae, Oribatidae, Formicidae, and Collembola were most abundant in this order, of which only the dipterous larvae were aquatic. The culicid larvae included Topomyia yanbarensis MIYAGI and Tripteroides bambusa bambusa (YAMADA), of which the former were dominant. Bacteria, Fungi Imperfecti, and Protozoa were also common in the water. The larva of Dasyhelea species was found throughout the year. Also, To. Yanbarensis larvae were collected all year round except midwinter when only dead bodies were found. No preference for the height of internodes was recognized for these Diptera species, at least in the range examined (up to 1.7 m above the ground). The Topomyia distribution per internode changed from contagious in the eggs to uniform in the 4th instar larvae via the random in the intermediate developmental stages. A single 4th instar larva usually occupied a single internode. Tr. b. bambusa increased in number when Topomyia density was low. This species occurred exclusively in the internodes near the ground.
A new distribution function of plant sizes in a stand was adopted to examine the stand structure of Cryptomeria japonica plantations. This distribution function was similar to PEARSON's type VII distribution. Limited by the 3/2nd power law of self-thinning, all the coefficients of this distribution density function were expressed as empirical equations of the population density of trees. As a result, a normalized distribution density function of individual tree weight in a stand corresponded to the 3/2nd power law of self-thinning.
Concentrations of Zn, Cu, Cd, and Pb in surface soils and annual plants, Capsella bursa-pastoris (L.) MEDIK. and Poa annua L., collected from 76 sites in Sakai City near Osaka were measured. The correlations among the concentrations of Cu, Cd, and Pb in the plants were significant (p<0.01), whereas correlations between Zn and the other heavy metals were not significant, and a negative correlation for Capsella suggested an antagonistic relation. Distribution maps of the heavy metals in the plants indicate that the main sources of the pollutants exist in the coastal industrial area and the adjacent downtown area in the northwestern section of the city. A power function was obtained between the distance from the center of pollution and the concentration of the heavy metals in the surface soils and plants. Except for Cd, the mean levels of heavy metal pollution in soils and plants in Sakai City showed that the soil and plant pollution has already progressed too far in Sakai City.
Field studies are described on the amounts of dissolved organic carbon (DOC) X in the soil solutions of a mixed forest and an intensive farm in situ on the campus of Tokyo Univ. of Agri. & Tech., Fuchu, Tokyo. Diurnal and seasonal fluctuations in the amount X of the two soils at a depth of 5 cm were almost independent of the changes in the soil temperature, the contents of soil water, the amounts of ammonium and those of nitrate ion in the soil solutions. The average amount X (g C/m^2,to a depth of 10 cm) and the coefficient of variation (%) throughout the year was 0.328 and 28.0 in the forest soil, and 0.160 and 36.3 in the farm, respectively. Being controlled strongly by the temperature, the rate of CO_2 evolution Y (g C/m^2/day) at 5 and 25℃, for example, was 0.73 and 2.13 for the forest excluding the respiration of root and macrofauna, and 0.51 and 1.22 for the farm, respectively. Assuming that the DOC was the respiratory substrate for the soil microbes, the higher rate Y of the forest than that of the farm was attributed to the difference in the amounts X between the two soils. Furthermore, the turnover rates per day of the amount X (ratio of the rate Y to the amount X) were calculated, assuming that all the CO_2 was evolved from the upper layer to a depth of 10 cm. Being controlled by the temperature, the turnover rate at 5 and 25℃, for example, was 2.2 and 6.5 for the forest, and 3.2 and 7.6 for the farm, respectively. The high turnover rate suggests the active production and consumption of DOC
Changes in the amounts and nutrient concentrations of litterfall in a forest in relation to soil fertility were studied. The results obtained in four 26-year-old Chamaecyparis obtusa stands and in 19 plots of natural deciduous broadleaved forests, all of which grew in different soil conditions, indicated that the production of leaf and total litterfall was positively correlated with soil fertility when the annual increment of stem velume of the stand or the mean height of the trees were used as an index of soil fertility. The weighted annual mean concentrations of N and P of leaf and total litterfall decreased with the decrease in soil fertility. There was no relationship between soil fertility and the concentrations of Ca, Mg and K in the litterfall. The quantitative effects exerted by soil fertility on the rate and nutrient concentrations of litterfall could not be assessed using the present experimental data. However, data showed that the amount of nutrients contained in the litterfall decreased in the poor soil compared to the rich soil, particularly for N and P, due to the decrease in production and nutrient concentration of the litterfall.
Precipitation (P) and stream flow rate (Q) were measured simultaneously in three watersheds : strongly burnt, moderately burnt and undamaged natural forests through the year from December of 1979 till November of 1980 at Etajima Island, Hiroshima Prefecture, west Japan, where a fire occurred in June of 1978. Rain fall (2077-2156 mm) in the year studied was 500 mm more than that in usual years (1575 mm), and threre was little difference of precipitation among the watersheds. On the other hand, discharge from each watershed increased at the burnt forest ; therefore, annual evapotranspiration, calculated as the difference between precipitation and discharge, decreased after the forest fire due to the loss of interception by the forest canopy and transpiration by plants. Annual ratio of discharge to precipitation (Q/P) was estimated at 0.657,0.604 and 0.519 in the strongly burnt, moderately burnt and natural forests respectively. This finding suggests that the discharge increased or the evapotranspiration decreased in proportion to the ratio of burnt area to its watershed area. Loss of the discharge per burnt ratio was calculated at 2.7mm/%, which was comparable to the value estimated from the data obtained in the deforested watersheds.
Concentration and mass of nutrients, pH and temperature in rain and stream water were measured every ten days throughout a year (December of 1979-November of 1980) at three watersheds : strongly burnt, moderately burnt and natural forests in Etajima Island, where a fire occurred in June of 1978 and burnt 1005 ha of forest, in Hiroshima Prefecture, west Japan. Annual range of temperature in the stream water was wider in the burnt forests than in the natural forest, and pH value of the stream water in the strongly burnt forest was always recorded lowest and nearest to that of the rain water in all sites. This finding indicates the problem of reduced buffer action of pH in the watershed-ecosystem after the fire. The concentration of nutrients in the stream was increased (K, Mg and Ca) or decreased (Na) with the increase of flow rate of discharge at all the watersheds. The relation between flow rate of nutrients (qV) and discharge (Q) was approximated closely by an equation : qV=a.Q^b+1. There was little difference in the value of coefficient b among the same nutriests whether the forest was burnt or not, while the value of coefficient α increased in proportion to the intensity of damage to forest by the fire. This suggests that coefficient α is a good indicator of degradation in a watershed-ecosystem. All nutrient balances, which were calculated as the difference between input (precipitation) and output (discharge), changed to minus at the three watersheds, but net loss of nutrients (except calcium)
To elucidate the factors and the significance of troop desertion by females which scarcely reported in Japanese macaque Macaca fuscata, 35 adult females who disappeared from T-troop in the Hakone area between April 1972 and March 1979 were examined. Of these females, 18 were discovered alive in this area. Most deserters were the aged and the eldest daughters of their matriarchs. Deserters tended to issue from lower rank kin-groups in the troop. There were inverse correlation between food supply and number of disappeared and/or deserted females. Behaviour of females after desertion was classified into eight categories : remaining alone or only with their babies, forming a pair with an adult male, forming new troops with members of her previous troop or with strangers, and immigration into an adjacent troop. The new type of troop formation here described differs from those by troop-fission so far reported. Female desertion probably caused by unbalance between food supply and the troop size was concentrated after a change of top-ranking male in the troop or during the mating season. Troopfission and deserters of both sexes function as one of the population controlling mechanisms within the troop and the expansion of the species habitat. Troop desertion by females is one of the phenomena that necessitate reconsideration of the social structure of Japanese macaques generally accepted.
In the alpine zone of the Daisetsu Mountains, there exist permafrost areas represented by special plant communities. To clarify the cause of this distribution, depth of active layer in middle July, vertical changes of soil temperature and depth of water table were examined.
The annual production rate of pollen grains was studied in 55-and 60-year-old plantations of Japanese cypress, Chamaecyparis obtusa SIEB. et ZUCC. in Mt. Hiei, Kyoto, for three years, 1978 to 1980. The production rates of male flowers after pollen release caught by litter traps were 11.35 kg ha^<-1>y^<-1> to 163.3 kg ha^<-1>y^<-1>, Mean dry weight of pollen grains produced per male flower (1.12mg) was obtained as the difference between mean dry weight of male flowers just before pollen release (1.99mg) and that after pollen release (0.870mg). The production rates of pollen grains in dry weight ranged from 14.59 kg ha^<-1>y^<-1> to 209.9 kg ha^<-1>y^<-1>, based on the ratio of dry weight of pollen grains per male flower to that of male flower after pollen release. One pollen sac of C. obtusa contained 2,495 to 4,675 pollen grains on an average, according to the position of cone scales on a floral axis and the number of pollen sacs per cone scale. Accordingly the mean number of pollen grains per male flower amounted to 198,200. The maximum value of production rates of pollen grains in number reached 3.72×10^<13> No. ha^<-1>y^<-1> for 1978,based on the ratio of number to dry weight of pollen grains per male flower.