SATOO, Taisitiroo (Dept. For., Fac. Agr., Univ. Tokyo). 1979. Production of reproductive organs in plantations of Chamaecyparis obtusa near an electric power plant in Owase, Mie. Jap. J. Ecol. 29 : 315-321. The production of cones, seeds, and male-flowers was estimated on three sample plots described in the previous paper. Production of cone and seed was much smaller in plots located within the same basin as the power plant than a plot located outside of it. Seed-fall was very slight before December when the greater portion of the seed fell, and it continued to decrease gradually until April. Any specific trend was not recognized in the seasonal pattern of cone-fall. Except for the largest trees, among the trees of the same diameter at breast height, production of cones and seeds was larger in the plot located outside the basin than those within it. Shedding of male flower occurred in April and May. Production of reproductive organs in the sample plots within the same basin as the power plant was much smaller than those in the plot which is separated from the plant by a mountain range.
OOHATA Sei-ichi (Kyoto Univ. For. Agr., Kyoto Univ., Kyoto) & SHINOZAKI Kichiro (Sci. Educ. Inst. Sakai City, Sakai). 1979. A statical model of plant form-Further analysis of the Pipe Model Theory. Jap. J. Ecol., 29 : 323-335. In the present study, the structure of stems in plant communities was analyzed as an extension of the Pipe Model Theory proposed by SHINOZAKI et al. (1964). A close correlation was found between the amount of non-photosynthetic tissue [C (z)] at the stratum z and the cumulative amount of plant weight [T (z)] from the top to that stratum. The relation between T (z) and C (z) is always linear, at least in the leafless range (trunk) in plant communities. A characteristic constant of this linear relation is herein referred to as the Specific Stress Length (SSL). This linear relation implies that the amount of nonphotosynthetic tissue increases exponentially downward. This trunk form may be physically interpreted in terms of a compressive stress distribution that is constant regardless of elevation. Statically, this form may be ideally suited for the purpose of supporting the plant body. Among the plant communities investigated, the values of SSL were always proportional to the community height. This statical model of woody tissue may be construed as a consequence of the pattern of accumulation of disused pipes that was proposed by SHINOZAKI et al. (1964).
ABE, Takuya (Dep. Biol., Sci. & Eng. Div., Univ. Ryukyus, Naha) & MATSUMOTO, Tadao (Dep. Biol., Fac. Sci., Tokyo Metropolitan Univ., Tokyo). 1979. Studies on the distribution and ecological role of termites in a lowland rain forest of West Malaysia (3) Distribution and abundance of termites in Pasoh Forest Reserve. Jap. J. Ecol., 29 : 337-351. The distribution and abundance of termites were studied in a lowland rain forest (Pasoh Forest Reserve) of West Malaysia. Fifty-two species were found in a 1-ha plot, 14 species in a 16 m^2 area and 10 species in a 2 m^2 area. Density and biomass of the entire termite population were estimated at 3000-4000/m^2 and 2.2-2.6 g. d.w./m^2 respectively. Dominant termites were Macrotermes malaccensis, M. carbonarius and Dicuspiditermes nemorosus. More than half of the entire termites (in biomass) cultivated fungi in their nests. Termites occupied all strata of the forest from the height of more than 30 m on and in the standing trees down to the depth of 30 cm in the soil. Termites living deeper in the soil than 30 cm are very scarce. Termites making subterranean and intermediate nests shared about two thirds of the total termite population in the number of species, density and biomass. Mound builders are not predominant, though they are important termites. The populations of arboreal nest making termites were low. The termites occupied an overwhelmingly dominant position among soil macrofauna in Pasoh Forest.
HIGUCHI, Hiroyoshi (Lab. For. Zool., Fac. Agr., Univ. Tokyo). 1979. Habitat segregation between the Jungle and Carrion Crows, Corvus macrorhynchos and C. corone, in Japan. Jap. J. Ecol., 29 : 353-358. Corvus macrorhynchos and C. corone use a wide variety of natural resources for food and habitat, and are typical ecological generalists. Because their food is already well known, the habitats of these generalists were investigated. A clear habitat segregation was recognized in this study, which was rather different from the general habitat description appearing in many bird books in Japan. The differences of habitats shown in this study were supported by the results of the examination of stomach contents. By comparison with the situations on the Asian continent, it was suggested that in Japan the habitat of C. macrorhynchos is constricted by sympatry with C. corone.
KACHI, Naoki (Div. Environ. Biol., Nat. Inst. Environ. Studies, Yatabe, Ibaraki) & HIROSE, Tadaki (Dep. Bot., Fac. Sci., Univ. Tokyo, Tokyo). 1979. Multivariate approaches to the plant communities related with edaphic factors in the dune system at Azigaura, Ibaraki Pref. II. Ordination. Jap. J. Ecol., 29 : 359-368. An ordination method of reciprocal averaging proposed by HILL was used in the study of the dune vegetation at Azigaura, Ibaraki Pref. and its relation to the edaphic environment was examined. Two types of vegetation pattern were recognized ; the one represented the changes of vegetation from the coastline to the inland and the other represented that in the inland dune area with a topographical gradient from concave areas to convex dunes. The former pattern of vegetation showed positive correlations with organic matter content and soil surface hardness and negative correlations with exchangeable cations. These environmental trends were considered to reflect the chronosequence of dune stabilization and soil formation which result from the decrease in salt spray, the leaching of minerals and the accumulation of organic matter. The latter pattern of vegetation showed positive correlations with organic matter content and mineral nutrients and a negative correlation with soil moisture. These environmental trends were related to the toposequence in the inland dune area-from moist, rather infertile low-lying areas to well drained, fertile dunes.
A.K. SINGH (Lab. Ecol., Fac. Sci., Chiba Univ., Chiba, Japan), R.S. AMBASHT & K.N. MISRA (Dept. Bot., Banaras Hindu Univ., Varanasi, India). 1979. Weight-loss and energy release of decomposing grass litter in a savanna ecosystem. Jap. J. Ecol. 29 : 369-374. Decomposition studies of grass litter, with respect to weight-loss and energy release, were made during May 1976 to May 1977 in a savanna ecosystem of Chandraprabha Sanctuary (24°52′ to 24°58′ N lat., 83°3′ to 83°12′ E long.) in Varanasi forest division. Known quantity of grass litter was kept in nylon bags and placed at soil surface in savanna stand. It decomposed at a fast rate and about 93.66 per cent of the total litter decomposed within a year, out of which three seasons rainy, winter and summer accounted for 64.48,18.60 and 10.58 per cent, respectively. CO_2 evolution rate, which was measured at monthly intervals, was correlated statistically with weight-loss and moisture content of litter. Highly significant (p<0.001) relations were achieved among them. Caloric values per gram of organic matter increased significantly till the end of rainy season possibly due to preferential decaying of lower energy content substrates, and after that it decreased cotinously. Annual loss of energy in the decomposition was 93.68 per cent of the total energy placed in the litter bag. Positive linear correlation significant at 0.001 per cent level was obtained between energy release (Kcal) and weight-loss (g).
SUZUKI, Eizi (Department of Biology, Faculty of Science, Osaka City University). 1979. Regeneration of Tsuga sieboldii forest. I. Dynamics of development of a mature stand revealed by stem analysis data. Jap. J. Ecol., 29 : 375-386. The process of regeneration was studied in a mature Japanese hemlock stand on Kubotani-yama, Kochi Pref., Shikoku, based on the stem analysis data obtained by clear-felling a 400 m^2 plot. The age distribution in trees and the restored change in their growth rates during sapling stage indicated that a strong disturbance and subsequent regeneration occurred some 270 years ago. The DBH census on wider areas made by the district forestry office suggested that such a large-scale regeneration might have taken place in mosaics of a few to several tens hectares, possibly due to the destruction by strong typhoons. Local disturbances and regeneration on a much smaller sacle were also presumed. The hemlock forest in this district seemed to have been maintained by these two types of regeneraton. Component species of the four layers (tall tree, mid-tree, small tree and shrub) were found to have respectively different growth rates, age limits and regeneration cycles.
KAWAHARA, Teruhiko, TADAKI, Yoshiya, TAKEUCHI, Ikuo, SATO, Akira, HIGUCHI, Kunio & KAMO, Koichi (For. & For. Prod. Inst. Ibaragi). 1979. Productivity and cycling of organic matter in natural Fagus Crenata and two planted Chamaecyparis obtusa forests. Jap. J. Ecol., 29 : 387-395. Amount of litter fall, soil respiration, net productivity and decomposition rate were measured in order to know the difference of organic matter cycling among five different areas ; Fagas crenata stand, middle aged and young Chamaecyparis obtusa stands and cut-over areas of both species. The values of biomass and net productivity in those stands showed reasonable ranges. There was little differences in amount of litter fall among the vegatations, but soil respiration at cut-over area was larger than at the forests. These facts suggest that the balance of soil organic matter is desturbed temporarily by destruction of trees, but recoverd gradually with the growth of planted seedlings. The steady state may be realized in Chamaecyparis obtusa plantations older than 40 years.
KOBAYASHI, Katsumi (Seikogakuin, Shizuoka) 1979. Studies on the growth and maintenance of patch of Miscanthus sinensis Anderss. I. Dynamics of shoot population and its relationships to expansion of patch area. Jap. J. Ecol., 397-401. The relationships between the dynamics of shoot population and the expansion or increment of patch areas of M. sinensis were investigated for two years from 1975 to 1977. A few of new shoots emerged at early spring and the main shoot gain was observed from early summer to late autumn. The latter period corresponded to the expansion period of patch area. But the course of areal increment of patch did not agree with that of shoot gain. The contributory rate of new shoot to patch area increment showed a remarkable seasonal variation. Three tillering times were distinguished during this period, and this suggested that the three tillerings formed different distributional patterns of new shoots from each other. The course of shoot loss had three peaks in a year, early summer, autumn, and winter. These shoot loss little affected the patch area. Many of the secondary and the tertiary tillers were overwintered, and these overwintered shoots played an important role in the ear production of shoot population.