The structure and species composition as well as their changes in a climax forest, dominated byPinus koraiensis-Tilia amurensis andFraxinus koraiensis, were observed with an interval of 10 years. The number of tree species was 16 in 1981, which was kept unchanged. Density was increased from 510 to 535 stems/hm², and basal area from 35.19 to 38.17 m²/hm². Average stand DBH remained nearly unchanged. The total mortality of the stand was very low, 0.61% per year.Fraxinus andPinus were declining in population size, the highest mortality rate for the former, and the largest death number for the latter.Tilia showed a rapid increasing of 14.9%, and the density of saplings (DBH 3-8 cm) was 71 stems/hm², led the top among canopy-layer species.Acer mono, similar toTilia, showed a type of continuous regeneration which was represented by the reverse J-shape of DBH distribution and compensation ability to mortality. Sub-canopy species such asAcer pseudo-sieboldianum, Maackia amurensis etc. presented a stable status by self-maintenance. Based on the fact of the decreasing of dominant populations, it is predicted that the composition of the community was changing gradually, the rising of broad-leaved components versus the declining of coniferous species.

Recovery of species diversity after catastrophic disturbance was influenced by a few factors, such as intensity of disturbance, availability of propagules, and the environmental conditions. In this paper, we examined pattems of species development after nearly 60a succession in burned broad-leaved Korean pine mixed forest on northem slope of Changbai Mountain. We assessed the recovery of plant species diversity in 3 types of forests under the condition with gradient of soil moisture. Results revealed that recovery of plant species diversity varied greatly under different environmental conditions. Species richness of secondary forests greatly related to the site condition. Secondary birch forest on mesic site had the greatest number of plant species and the following was poplar-birch forest and larch-birch forest. Most of characteristic taxa could be found in birch forest after 60a succession. For larch-birch forest on hydra site, most of climax species were still not able to invade, so it had the lowest species diversity.

The modification in structure, composition, and diversity, shrub, as well as herb strata ofPinus koraiensis-Tilia amurensis-Abies nephrolepis forest after 16a of selection cutting in northeastern China was studied. In the selection cutting forest, individuals with small DBH classes characterized size distribution. The virgin forest, on the other hand, was mainly composed of individuals having larger DBH classes. The density of dominant species and the species diversity at tree stratum in the selection-cutting stand was significantly larger than that of in the primeval forest. The shrub layer also showed a similar result. However, the herb layer had comparatively low species diversity. Large growing space and strong light in the artificial gaps must have provided opportunities for the species of shade tolerance or shade intolerance to establish on the stand. The juveniles of non-pioneer species, which were hardly found in highly shaded virgin forest, were also released by the disturbance. Regeneration in the selection-cutting stand was prompted by the disturbance, where the density of saplings occurred nearly 3 times as much as that in the virgin stand. The growth of shrub layer was improved due to the alteration in light condition. The projection volume of the herb layer was less affected. Restoration of a semi-virgin forest to the original status after selection cutting could be possible in several decades. However, for those subjected to clear cutting, it might take several centuries. In order to promote biodiversity, it is reasonable to practice selection cutting in communities for consisting of species with various levels of shade tolerance.

With the concern of regeneration, characteristics of canopy gaps in broad-leaved Korean pine forest were studied. The areas of actual gap, expanded gap and maximum gap were analyzed respectively. The species composition, number, origin, decayed class and sizes of gap makers were studied comprehensively. The comparative studies of regeneration inside and outside of canopy gap showed that the density of regeneration inside canopy gaps was 30% higher than that outside canopy gaps. The specific species regeneration response to canopy gap varied greatly.Pinus koraiensis, Picea jezoensis Fraxinus mandshurica, Juglans mandshurica andAcer mono generally did not response to canopy gap disturbance. The Regeneration Importanice Value (RIV) ofAbies nephrolepis, Ulmus Japonica increased with canopy gap disturbance. RIV ofTilia amurensis, Acer madshurica and Ulmus laciniata decreased with canopy gap disturbance. Canopy gap disturbance was not strong enough to result in the regeneration of some species of shade intolerance such asLarix olgensis, Betula platyphylla.

A simulation study on the responses of forests in Northeastern China to possible climate change was done by running NEWCOP, a computer model of forest stands “gap” dynamics with a set of parameters of 24 tree species. Based on the simulation, climate change will continue to make coniferous trees less and less and deciduous trees more and more. By the end of 100a transient process and 100a equilibrium climate period, forest biomass is reduced by a total of 6,531 million t dry material for the whole region of NE China. There is only a small area in the north on which there stands more biomass than without climate change. Korean pine will be first tree species which decrease by the most amount. In the northern part of NE China, oak forest will cover much more area with climate change and the larch forest may cover less area than it does at present. In the middle part areas, coniferous and broad-leaved mixed forest will remain, but the portion of deciduous species in composition of forest will increase. In the southem part areas, Korean pine will become companion tree species and its distribution area will greatly decrease.

Studies were carried out on the spatial pattems of dominant species and gaps, and the influence of which on the regeneration in the broad-leaved Korean pine forest on the north slope of Mt. Changbai. The result showed that many deciduous tree species have high growth rates and become more competitive due to the more mild and humid climate at Mt. Changbai. No obvious aggregated distribution pattern was showed. In this forest small gaps are most frequent, with even distribution, which may be beneficial to survival and growth ofPinus koraiensis saplings.

A succession and silviculture model (ZELIG.CBA) for broad-leaved Korean pine forest of Changbai Moutain Area was developed based on the framework of ZELIG model and characteristics of Broad-leaved Korean pine forests of Changbai area. ZELIG.CBA model consists four sub-models: growth model simulating annual increment of individual tree in forest, regeneration model simulating annual establishment of different tree species, mortality model simulating annual agerelated and stress-related morality; and silviculture model simulating the forest response to different silviculture scenario. The validation of the ZELIG.CBA showed that the accuracy of the model for the forest growth was more than 95%. The succession from clear cutting site simulating showed that the ZELIG.CBA model was stable for long term simulation. And selective cutting experiment showed that the optimal scenario for broad-leaved Korean pine forests was removal volume 30% combining with 30a rotation.

Based on a vast of field investigation on stamps inTilia broad-leaved Korean pine forest on northern slope of Changbai Mountain, age structure of some major species were studied in this paper. The results showed that Korean pine population was composed of grouped patches with different ages. There were not strict intervals among the dominated generations, and the curve of age structure often had two or more peaks. The distribution of broad-leaved species in natural Korean pine forest was grouped or scattered, and age distribution was also uneven-aged. There existed close relation between quality of broad-leaved species and Korean pine. So, it shaped multi-storied and uneven-aged mixed forest. The model of age structure and growth demonstrated their passive correlation, but growth became slow when woods had reached old age.

Soil samples were taken from different soil depth of different forest soil story in the Natural Reserve of Changbai Mountain, and their saturated conductivity and effective porosity were measured. The variation of saturated conductivity and effective porosity with different soil depth were studied by regressive analysis and a logarithmic model. The results were compared with the exponential model (Beven 1982). The results of comparison showed that the logarithmic model was more accurate and reasonable than the exponential model for forest catchment.

The soil CO₂ evolution rate was measured in a virgin Korean pine forest. The results in June showed that the lowest value of evolution rate was 220 mg/(m²·h) and appeared at 6:00 a.m. The highest value was 460 mg/(m²·h) at 18:00. The rates of CO₂ evolution were related with soil temperature. On the basis of the constructed regression equation and the monthly average values of temperature, the magnitude of CO₂ evolution from Korean pine forest soil was 10.4 t/hm² during a growing season.

Fallen wood decomposition rate ofPinus koraiensis andTilia amurensis in broadleaved Korean pine forest was studied in this paper. The result showed that decomposition rate of fallen wood was different from that of little diameter wood and coarse woody debris for the same tree species. Fallen wood decomposition was generally rotten from outside to inside. And decomposition speed of fallen woods was different according to tree species and site, and it was also related to diameter of fallen woods. Decomposition depth ofTilia amurensis fallen wood for 17 years was 14 cm, but that ofPinus koraiensis in the same condition was less than 7 cm.Tilia amurensis was decomposed faster thanPinus koraiensis. For same tree species, if the diameter was small, the decomposition speed was quick.

The spring home range and social behavior of Hazel grouse, (Bonasa bonasia) were studied at Changbai Mountain using radiotelemetry in 1993–94. Flock dissolution and pair formation started in mid-March. Paired males held territories in spring, the area was from 3.2 hm² to 17.3 hm² (n=2). Hazel grouse was proved to be monogamous by radiotelemetry work. The overlap of home range between paired No.10 and No.8 was 82.4%. The time of birds being together was 83.0% of the time during the prelaying period (n=53), showing that the pair bond was stable. Unpaired males showed different behavior, held a territory or wandering, and they changed their behavior in early May. The study suggested that unpaired males gave up their reproduction goal, and the acquisition for survival became more important in early May, when female started incubation.

Changbai pine (Pinus sylvestris var.Sylvestriformis) is an endemic and important tree species in Changbai Mountain. There were only 63 plant species in Changbai pine plantation, where hemicryptophyte was dominant(39.68%). Simpson diversity index was 0.87, Shannon-Wiener diversity index was 2.96, and evenness index was 0.82. Community structure were divided into three layers: tree layer, shrub layer and herb layer. The total biomass and net production were 111.982 t/hm² and 8942.80 kg/(hm² a) respectively. The total biomass for tree, shrub and herb layers were 106.150, 2.230, 2.264 t/hm², accounting for 94.79%, 1.99%, and 2.02%, respectively, and net production for those were 7465, 223, and 1182 kg/(hm² a), accounting for 83.47%, 2.49%, and 13.22% of the total respectively. The nutrient content in various organs is in the order of needle> branch> root> bark> trunk, For the assimilated organ, the nutrient content is in the order of N> K> Ca> P> Mg, and that in absorption organ is in the order of Ca> N> K> P> Mg. For the whole plantation ecosystem, nutrient content is in the order of soil> litter> herb layer> shrub layer> tree layer. Nutrient storage and its accumulation rate in tree layer take up 88.79% and 76.43% of the total, respectively.

The flux of N in broad-leaved Korean pine forest land, Changbai Mountain, Northeast China was studied with thein situ sequential coring technique. The results showed that, in the growing season of 1994 (May to September), net rate of mineralization was 47.96 kg/hm², plant uptake 28.37 kg/hm² and leaching losses 20.47 kg/hm². Net N mineralization rate exceeded plant uptake requirements. On the basis of the N budget, this forest land could be characterized as N saturated though more detailed studies are needed.

Ecotourism has been suggested as the altemative for the conflicts between tourism development and nature conservation especially for the protected area, such as biosphere reserve. Based on investigation of tourism resources of The Changbaishan Biosphere Reserve (CBR) and tourism impacts on environment, economy and society, the potential of ecotourism development is analyzed in and around CBR. The results showed that the conditions in the study area are suitable for development of ecotourism, which is an effective approach for sustainable development of CBR.

This paper is focused on ecological assessment of the status of bio-diversity, and a strategic plant for biodiversity conservation on a sustainable basis. It described the present situation, the causes of bio-diversity degradation, and the approaches for conserving, utilizing and developing bio-diversity in Changbaishan Biosphere Reserve.

The water beetles recorded from Changbai Mountain are listed. Amphizoa sinica Yu & Stork and Ametor scabrosus (Horn) are distributed only in Changbai Mountain area. The habitat of water beetles in each locality is described.

Bases on studies of bryophytes collected by Cao Tong in August 1997 from North Korea, 81 species belonging to 52 genera, 26 families of mosses and 16 species belonging to 12 genera, 10 families of hepatics are recorded. Among these, 6 species and 1 form are new to bryoflora of the Korean Peninsula. These are:Campylopus gracilis (Mitt.) Jaeg.,Grimmia leavigata (Brid.) Brid.,Okamura hakoniensis f.mutiflagellifera (Okam.) Nog.,Orthotrichum erubescens C. Muell.,Scapania verrucosa Heeg.,Schistidium strictum (Turn.) Loeske ex O. Maort. andSchistidium subconfertum (Broth.) Deguchi.