Budburst timings of Castanopsis, Machilus and Quercus (subgen. Cyclobalanopsis) were studied at 17 different areas, from Natori in the Tohoku District to Iriomote Island in the Ryukyu Islands. Budburst is defined here as a stage in which the blades of the first new leaves just begin to unfold. Firstly, sprouting processes of Castanopsis and Machilus shoots were frequently observed in Chiba. Secondly, sprouting stages of new shoots were recorded for these three genera at a suitable season in each area. Based on the data regarding sprouting processes obtained in Chiba, and the sprouting stages observed at different dates and areas, budburst timing at each area was determined. Resultant budburst timings of Castanopsis in the areas from south to north were as follows : late Dec. to early Jan. in Iriomote : mid-Feb. to early Mar. in Okinawa ; late Mar. in Tokunoshima ; mid-Mar. in Yakushima ; late Mar. to late Apr. in Ohsumi Peninsula ; late Apr. in Nara ; early Apr. to late Apr. in Boso Peninsula and early to middle May in Natori. Many of the Machilus and Cyclobalanopsis species also seemed to open their buds around the same time as the budburst of Castanopsis, at all the places. Dominant species of lucidophyll forests thus sprouted earlier in the south and later in the north, although the delay due to the variation of latitude and annual mean temperature was smaller in the north. These observations were generally consistent with the rough descriptions on shoot sprouting which is reported locally in other literatures. Therefore budburst timing of dominant species of lucidophyll forests in Japan seems to be delayed towards the north, while keeping its synchronism among species.

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Differences of budburst timing of Castanopsis sieboldii (Makino) Hatusima ex Yamazaki et Mashiba (incl. ssp. lutchuensis (Koids.) H. Ohba) reported in Japan, were discussed from the point of view of air temperatures around the budburst period, frost period and the optimum for maximizing annual photosynthetic gain. Firstly, daily mean, maximum, and minimum temperatures during and immediately before the budburst were compared. It revealed that air temperatures were generally different between mainland Japan and the Ryukyu Islands, and within the Ryukyu Islands themselves. This suggests that later budburst in the north cannot be fully ascribed to the delayed arrival of the same warm temperature conditions. Secondly, actual budburst timing of Castanopsis sieboldii and the normal frost period of the areas were compared. Budburst timing generally corresponded to the end of frost period in mainland Japan. Thirdly, a model for estimating the annual photosynthetic gain was proposed using the maturation and aging process of Castanopsis sieboldii leaves, and the relationship between photosynthetic rate and temperature. By simulating this model using the air temperature data at six different locations in Japan, optimal timing of budburst for maximizing the annual photosynthetic gain was obtained. The resultant optimal timings of budburst coincided with the actual timing in Ryukyu Islands where no frost occurs. In mainland Japan, the optimal timings fell within the frost period and did not coincide with the actual budburst timing. However, actual budburst timings in mainland Japan led to the largest annual photosysnthetic gain in the simulation outside the frost period. Therefore, budburst timing of Castanopsis sieboldii may be scheduled to maximize the annual photosynthetic gain, while avoiding frost damage.

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Owase District in Mie Prefecture, located on the south-east side of Kii Peninsula, is one of the wettest region in Japan. Annual precipitation in Owase city is more than 4,000 mm, and warmth index is 128.7℃・Month. Consequently, laurel forests have been able to develop on lowland and mountain slopes. Firstly, a phytosociological study was made of the laurel forests, which were classified into six community types : A, B, C, D, E and F. Pittosporum tobira community (A) is located on the seashore. Quercus phillyraeoides -Pittosporum tobira community (B) is on windy, steep slope, near the seashore. Quercus phillyraeoides - Dicarnopteris dicotoma community (C) is on sites with conditions similar to those of community (B). Castanopsis cuspidata var. sieboldii - Symplocos glauca community (D) and Castanopsis cuspidata - Photinia glabra community (E) are located from the seashore to lower elevations of mountainsides (<400m). On higher mountainsides (about 400〜700m) Quercus salicina - Cleyera japonica community (F) is found. Secondly, I investigated the relatioship between the six community types and site conditions. Owase District is a very wet region, but there are dry sites on the mountainsides where communities A, B and C are found. On less xeric sites, Communities D and E are distributed. On the basis of these results, the relationship between environmental gradient and community structure (complex sinusia) is discussed.

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Floristic composition was investigated in the Malus baccata var. mandshurica bush on the sand dunes along the Sea of Okhotsk, in eastern Hokkaido. A phytosociological association, Lonicero - Maletum baccatae, was newly recognized. Its characteristic species are Malus baccata var. mandshurica, Lonicera chrysantha var. crassipes and Sambucus sieboldiana var. miquelii. In the case of the M. baccata var. mandshurica bush, only Roso〜Maletum mandshuricae (Tatewaki 1961) Ohba, Miyawaki et Tx. 1973, has been reported. It belongs to Rosion rugosae Ohba, Miyawaki et Tx. Lonicero-Maletum baccatae lacks Rosa rugosa and Artemisia japonica, but it has many species common to the Angelico anomalae - Quercetum dentatae (Tatewaki 1961) Ohba, Miyawaki et Tx. 1973, the climax forest on coastal sand dunes. It also has many of the character and differential species of its upper unit. Thus Lonicero-Maletum baccatae belongs to Quercion dentatae Miyawaki et Yasushi Sasaki 1980. Fixation of trees in coastal sand dunes is difficult because of the severe environment as a dense sand dune vegetation cover, the strong sea wind and so on. Seeds of M. baccata var. mandshurica are dispersed by birds and can produce root-suckers, allowing it to grow in coastal sand dunes as a pioneer shrub.

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Butterfly assemblages were investigated using route census surveys, at Flowertown in Sanda from April to October, 1994. In order to evaluate the naturalness of vegetation through the species composition of butterflies, we proposed a butterfly index, which indicated the degree of naturalness of the habitat. The values of species diversity, averages of the butterfly index, and values calculated by the Bray-Curtis ordination method were calculated for eight vegetational conditions ; outside fragmented forest ; inside fragmented forest ; outside grassland ; inside grassland ; park ; detached house ; multiple dwelling house ; bare area. The results showed that the species diversity and butterfly index were highest in fragmented forests, and were lowest in the bare area. Ecological distribution of butterflies was classified into four types ; forest-type ; grassland-type ; park-type ; others. Many butterflies belonged to the forest-type classification, since there were many plant communities in the fragmented forests, such as Rhododendro macrosepali-Pinetum densiflorae, Quercetum variavili-serratae, Alnus japonica-Ligustrum obtusifolium Comm. Apanantho-Celtidetum japonicae, Querces acutissima Comm. etc. It seemes that fragmented forests are a very important habitat for butterflies, in spite of the small size of such forests. Butterfly assemblages at Flowertown were compared with other localities, including Mino Park, Hattori-ryokuchi Park, Osaka Castle Park, etc. Mino Park, Mt. Nijosan and Mt. Sanageyama were estimated to be at the secondary vegetational stage, while Osaka Castle Park, Nagai Park and Daisen Park were estimated to be at the urban stage. Although Flowertown was at the secondary vegetational stage in terms of butterfly fauna, it was at the residential-urban stage in terms of butterfly assemblages.

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Effects of burrowing by streaked shearwaters (Calonectris leucomelas) on the lucidophyllous forest (association : Arachniodo-Castanopsietum sieboldii) were studied on Ohshima Island in Mie, Japan in 1991. The association was divided into a Damnacanthus indicus variant (differential species : Damnacanthus indicus and Eurya japonica) and a Cocculus orbiculatus variant (differential species : Cocculus orbiculatus, Pueraria lobata and Menispermum dauricum, etc.) which were non-burrowing sites and burrowing sites, respectively. The D. indicus variant was characterized by forest floor species including character species of Camellietea japonicae, while the C. orbiculatus variant was characterized by forest edge species including character species of Rosetea multiflorae. The vegetative differences between the D. indicus variant and the C. orbiculatus variant clearly reflected the ecological characteristics of non-burrowing and burrowing sites. The burrow density of the seabird was low (6.0 + 2.0/100 m^2) on the island. The burrows were found mostly under the roots of trees (62.2%) , and their distribution pattern was aggregated (1_δ=1.67). This may suggest some selection of habitat by streaked shearwaters. The percentage of therophyte (annual plant) was significantly high in the burrowing sites, while the percentages of character species of Camellietea japonicae and canopy cover were significantly low. It is suggested that biotic interactions by streaked shearwaters tended to modify vegetation and destroy forest structure, even though the rookery density was low. The relationship between vegetative structure and habitat of streaked shearwaters, and rookery site selection in the vegetation are discussed.

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