An investigation was performed to establish the mathematical theories of a vibration for the plant growth and a wave distribution of a plant population on the boundary condition of a limiting factor in the environment. The mathematical theories of the plant growth vibration and wave distribution had been elucidated by the plant growth and the timber line on the middle slope of the west side of Mt. Paektu. The Betula ermaruii composes the timber line on about 2,060 m elevation of sea label, has a growth vibration on the ground surface and takes a wave distribution due to a boundary condition of alpine temperature gradient.

Mt. Paektu(2,749.6m)m the biggest mountain in Northeast Asia, located on the border line of Korea and China is characterized as an aspite with broad gentle mountain area and rich biota. however, it seems that the study of forest vegetational feature or vegetation zones in the whole area of this mountain is not yet sufficient in spite of contribution by many investigators. in this paper thermal climatic approach was carried out for the determination of vegetation zones of the mountain with the meteorological data of four stations including Cheonjj and various vegetational data. the application of Warmth Index and/or coldness Index(Kira 1977) for the determination of forest vegetation boundary was useful also here, and their boundaries largely coincided with those of thermal indicies obtained in the Korean Peninsula(Yim and Kira, 1975), including the lapse rate of air temperature along increasing elevation. However, in the mountain the boundary of vegetation zones in not clear like those of mountains in Korea. It may be due so the topographic differences between this area and the Korean Peninsula. Besides, the broad ecotones between different vegetations in this area support the vegetation continum concept rather than the unit concept, and the limit of timber line or tree line reflects various hypothesis(Steven and fox 1991). Therefore, for the explantion of vegetation zone of this area should be considered topography or soil condition, for example, as known the hierachy of ecological units (zonobiomes, orobiomes and pedobiomes, Walter, 1973).

The vegetation of alpine and subalpine zone from timber line, 2,000m altitude, to the upper area of Mt. Packtu were investigated by phytosociological method. The plant distribution along to the different altitudes shown as follows: Betula ermani community with Rhododendron redowskianum occupied dominantly at 2,000m area as patch forms, Rhododendron redowskianum community with Vaccinium uliginosum, at 2,180-2,200m area, both Vaccinium uliginosum and Rhododendron redowskianum community were compatible with each other at 2,243m area. Rhododendron redowskianum community at 2,250, Salix rotundifolia community, Erigeron thunbergii var. glabrata community, Dryas octopetala var. asiatica community and Carex atrata community were occurred frequently at 2,263m around Chonji Lake. Rhododendron aureum, Thunbergii coccinea and V accinium uliginosum showed higher cover degree than other species at 2,370m area, Phyllodoce coerulea-Rhododendron aureum community at 2,400m, Rhododendron redowskianum community at 2,470m, Rhododendron aureum community at 2,490m, Salix rotundifolia at 2,520m, Rhododendron redowskianum community at 2,580m, Dryas octopetala var. asiatica community, Salix rotundifolia, and bistorta achotensis etc. at 2,650 altitude area were settled as sparse, creeping shape on the surface soil and dwarf plants of about 15cm heights.

This study was carried in Mt. Paektu on the border between North Korea and China. The dominant communities of evergreen broad-leaved trees were Rhododendron aureum community, Dryas octopetala var. asiatica community, Rhododendron redowskianum community and Phyllodoce coerulea community. The evergreen broad-leaved trees investigated consist of a total 34 taxa : 4 forms, 16 varieties, 14 species, 10 genera, 5 families in Mt Paektu and North Korea(in literature). The soil organic matter and available phosphorus were different according to plant community and altitude.

The flora and vegetation of the alpine grassland at Dalmoon on Mt. Paektu were investigated on July 24, 1997 by 1 m ${\times}$ 1 m quadrat method. The flora of the vascular plants investigated on this alpine grassland was 36 taxa belonging to 17 families, 35 genera, 29 species, 3 subspecies, 4 varieties. Te leading families were Compositae (7 taxa) and Gramineae (4 species), and the forb was more than the grass. Four dwarf shrubs which were Salix metaformosa, Dryas octopetala var. asiatica, Rhododendron aureum and Vaccinium vitis-idaea were found at the studied sites. This alpine grassland was composed of 17 communities, Astragalus uliginosus, Sanguisorba sitchensis, Deschampsia caespitosa were dominated over 18, 5 and 4 quadrats, respectively.

The results of a week-long exploration, which was conducted on the soil mite of Mt. Paektu area by our team of the Ecological Society of Korea from July 22nd till July 27th of 1997, are as follows. All mite were picked and examined from the soil of 2,000 cm$^{2}$ from eight respective zones. The total number collected was 384 individuals with 20 families, 33 genera, 38 species including 42 individuals of unknown species. They were classified and identified as 13 families 18 genera 22 species of Oribatei, 4 families 11 genera 12 species of Mesostigmata, 2 families 3 genera 3 species of Prostigmata. Among them 5 species of Laelaptidae, Ascidae and Uropodidae couldn't be classified and identified owing to the shortage of reference. in alphine tundra zone 91 individuals were found, which outnumbered than that of the other surveyed areas. The mite that existed evenly in all around the surveyed areas was Tectocepheus sp. and 32 individuals of them were collected from the virgin forest zone. A comparatively small number of mite was found from sungsaha and the intersection of three streets in Mt. Paektu and Songkangjin town, which accoumts for soil picking from unsuitable places.

The occurrence and distribution of dictyostelid cellualr slime molds were investigated in forests of Mt. Paektu. Fourteen species were isolated from forest soils of thirteen sites as follows Dictyostelium minutum, D. brefeldianum, D. crassicaule, D. capitatum, D. mucoroides var. stoloniferum, D. macrocephalum, D. mucoroides, D. septentrionalis, D. purpureum, D. aureo-stipes, P. violaceum, P. pallidum and two unidentified speceis. Mean total clones and species found were 4,415.69 No./g and 2.92, respectively. Dominant species were D. minutum, D. brefeldianum and D. crassicaule in this study area, and first widespread species was D. minutum. All sepecies that found in Mt. Paektu were isolated from forests of South Korea. But dominant species was different from those of South Korea. Total clones and species were more in subalpine Eurya japonica than in low elevated abies nephrolepis. It was thought that distribution of dictyostelids was related to soil microenvironments by vegetation, not or not more elevation.

In order to clarify the species composition of freshwater zooplankton community inhabiting Lake Sochonji and chonji on the top of Mt. Paektu, the present study have been carried out based on the materials collected during the periods from 24 to 25 July, 1997. As a result of examing the specimens, from the Lake Chonji, a total of 10 species (Keratella cochlearis cochlearis, K. quadrata quadrata, K. valga valga, Notholca squmula squmula, Colurella adriatica adriatica, Lepadella patella patella, Lecane hua luna, L. (Monostyla) bulla bulla, Cephalodella gibba gibba, philodina roseola) appeared rotifers only. >From the lake Sochonji, a total of 7 species were identified. It consists of 3 species (Keratella valga valga, Cephalodella gibba gibba, Asplanchna (Asplanchnella) brightwelli) of rotifers, 2 species (Daphnia hyalina, Alona quadrangularis) of cladocerans, and 2 species (Acanthodiaptomus pacificus, Bryocamptus zschokkei caucassicus) of copepods, respectively. Also, appeared nauplius of copepoda.

Physicochemical factors, microbial population size and the properties of the bacterial isolates were assessed to find out the nature of soil ecosystem of Mt. Paektu. Samples were obtained from the surface layer of soils on which specific plant community is developed. Average content of moisture, organic matter and avaiable phosphate of the soils were 21.6%, 17.3% and 2.48mg/100g, respectively. These values were similar to those of developing forest soils, but were slightly lower than those of climax ecosystem such as Piagol in Mt. Chiri. The population size of soil bacteria ranged from 2.7 to $202.5{\times}10^5$ CFU/g.dry soil, and the size is somewhat dependent on the content of moisture and oranic matter of the forest soil. A large number of bacteria was able to decompose macromolecules such as starch, elastin and gelatin. While the distribution rate of resistant bacteria to antibiotics was high, that to toxic chemicals was low. This means that the competition between microorgani는 predominate over the interference with artificial behaviour such as spread of pesticides in the surveyed region. Bacterial species composition of each soil was comparatively simple. Pseudomonas, Agrobacterium, Flavobacterium and Xanthomonas which are Gram-negative short rods were widely distributed in the forest soils. The endospore forming Bacillus species were also main constituents of the soil microflroa. any one of the strains was not identified as Azospirillum or Micrococcus which are known to be one of major constituents of the forest soil. for the correct identification of isolates chemotaxonomic studies will be proceeded, and the strains are to be stored in the Type collection Center.