A palynological study was made on the Holocene sediments of two sites in south western Japan, Ukishima-no-mori moor, Shingu City, Wakayama Prefecture, and the Mutotsu River, Muroto City, Kochi Prefecture. At Ukishima-no-mori moor, the pollen diagram was divisible into three local fossil pollen assemblage zones, (1) the Quercus (Lepidobalanus)-Carpinus zone, (2) the Castanopsis-Quercus (Cyclobalanopsis) zone, and (3) the Cryptomeria-Pinus zone. It was estimated that broad-leaved deciduous forest had changed into lucidophyllous forest prior to the KAh ash fall which occurred about 6,300 years ago and that lucidophyllous forest, especially Castanopsis-type, would be dominant around this moor. This transitional age preceeded that occurring in Central south western Japan. At the Murotsu River, it seemed that the Castanopsis forest, which was accompanied by Podocarpus and Myrica spp., reached its climax phase about 8,500 years ago. These findings may be explained by the fact that in the early Holocene, the surveyed areas were situated on the Pacific coast and had been influenced by the warm Kuroshio current.
A survey was made of the distribution and habitats of water striders at various ponds in Toyama prefecture, Japan. Six species were recorded, Gerris elongatus, G. paludum japonicus, G. gracilicornis, G. yezoensis, G. insularis and G. latiabdominis. G. yezoensis was distributed from the upper mountain zone up to the alpine zone, whereas the other species were found from the coastal zone up to the mountain zone. G. elongatus and G. paludum japonicus live mainly on wide and sunlit areas of water, G. gracilicornis and G. insularis on narrow areas and G. latiabdominis on sunlit areas. Within the area of a pond, water striders were found to distribute from the shore to the center in order of body size, smaller to larger, respectively. Thus, each species utilizes a different part of the pond surface ; a spacing mechanism which enables several species to coexist in a pond.
The canopy of forests formed in the low areas of Kushiro moor was composed of only one species, Alnus japonica var. arguta. Leaf emergence and leaf fall of this species in the forests is discussed. Leaf emergence began in late May and continued until July. Leaf fall began in June, increasing in early July, and by October, all leaves had fallen. There were three peaks in the leaf fall pattern of this species in Kushiro moor. The first peak occurred from early to middle July and was mainly due to the leaf fall of the first and second leaves of shoots which had short longevity. This peak was, however, small in mass because the size of these leaves were very small. The second peak occurred in early August and the third peak, between September and October. These latter two peaks were large in both mass and the number of fallen leaves.
Life histories of 16 males and 3 females and survival records of 9 injured individuals of the Japanese toad, Bufo japonicus japonicus, are described. Sixteen males which lived from 8 to 11 years participated in the breeding ritual an average of 5.1 times, mated females an average of 1.3 times, and reached 119.7mm in snout-vent length throught their lives. Three females which lived from 7 to 9 years spawned 2.7 times and reached 117.0mm. Extensive data was provided by one male without a left hind leg which was recaptred 55 times during his 8 years life. The fact that this male participated in the breeding ritual 4 times, successfully copulated once, and reached 114mm in body length illustrates that intraspecific competition in the Japanese toad is not as severe as in other species.
Paddy fields and ditches around irrigation creeks constitute temporary waters flooded only in summer. In order to consider the significance of such temporary waters for fishes, the movement and behaviour of fishes in temporary waters and a permanently filled creek were investigated near the town of Yagi, Kyoto Prefecture. Among twenty-three species identified in the study area, seven species frequently entered the temporary waters, six of which utilized these waters as spawning sites. Two species were seldom found in the temporary waters, in spite of their abun dance in the permanent creek. The remaining fourteen identified species were rare in the study area. Fishes which frequently utilized the temporary waters for spawning had a similar reproductive habit, i. e., they scattered many eggs widely and showed no parental care. It is considered that many fishes, including juveniles, were foraging on the plankton which became abundant in the temporary waters after irrigation. It is surmised that newly emerged habitats of temporary waters with high productivity serve for the maintenance of a rich fish fauna in irrigation creeks.