This paper reviews the researches on old-growth korean pine (Pinus koraoensis) forest in Northeast China. The ecological characteristics of the forest were summarized. According to the research results, the importance of studying and reserving on the old-growth forest was addressed, which were the indispensable research laboratory and classroom for forest managers. The conclusions indicate that the future of Korean pine forest management should be based on the research results of old-growth forests.

From ecological viewpoint, the most fragile river system among the four basins in China which are Zhujiang, Changjiang, Huanghe, and Heilongjiang is Heilongjiang Basin. The reasons are long-term “paying attention to utilization rather than to maintaining” in agriculture and “paying attention to getting rather than to giving” in forestry in addition to its scarce water resource, weak self-cleaning capacity, thin and soft soil, weak capacity of vegetation recover, etc. Those cause that the resources are consumed extravagantly, and ecological environments evidently worsen. To check the situation above and carry out sustainable development of forestry, we have to change the basic concepts, to set up the nature viewpoint of harmonious development of human and nature, to acknowledge that forestry can produces not only economic products but special ecological and spiritual products as well as, of which the latter two can not enter markets for circulation so that a compensation system must be set up in the national economy, to confirm that the soil and water conservation functions of mountainous forests are the key in region planning, to keep that the minimum slope is 6° for safe guarding the soil and water of erosion in mountainous area, and forcefully to develop ecological forestry of which the core is “low lose but high efficiency.”

The regeneration, tree growth, and community structure and dynamics were studied in old-growth Korean pine (Pinus koraienisis) forest The results showed that the formation of tree fonn and growth character have been obviously related with the gap-phase regeneration. The ecological effects of the gap suppress the tree growth in diameter, and control that young tree stem fork in early stage. The heterogeneity of tree growth in time and space is the results of high quality in tree height and diameter. The hardwood species which mixed with Korean pine have different ecological effect on regeneration and tree growth of Korean pine in the early stage of gap reconstructing. Community dynamics depends on tree gaps occurs, in which a “cyclic succession” between Korean pine and hard wood species may occurs. The process would take about 200 years.

Korean pine (Pinus koraiensis) interspecific competition and intraspecific companioned with other species competition in old growth Korean pine forest in Northeast China were studied using Hegyi’s competition index model for individual tree. The results show that differences of competitive intensity exist in interspecific and intraspecific for Korean pine with an order of intraspecific >Abies nephrolepis Picea koraiensis Tilia amurensis Betula costala Acer mono Ulmus propinqua Populus davidiana, and that relationship of competitive index to individual size (in DBH) of objective tree follows closely multiplicate equation and that competitive intensity gradually reduces with increasing of individual size of objective tree, but it is tending towards stability after individual of objective tree increase to specified size (DBH about 20 cm).It provided a serviceable approach for researches of intraspecific relationship in population ecology.

The generation identification of Korean pine forest is discussed from a variety of aspects. Traditional methods of generation identification (according to age structure or morphological data) are thought to be inaccurate. Only when the connotation of generation is expanded, that is, the spatial property be considered, can the generation be identified correctly and digenesis be explained reasonably.

A new method was proposed to study the dynamics of stem form of natural Korean pine (Pinus koraiensis) tree. In natural Korean Pine forest, the occurring time of maximum height and diameter is very difference. This paper connected stem form to stage of tree growth to analysis the form dynamic of Korean pine. The monpmolecular equation was chosen as the stem model. The result shows that the maximum growth year of natural Korean pine is earlier than diameter.

Shannon diversity index and its evenness are used to analyze the difference of higher plants in broad-leaved Korean pine forest and secondary birch forest. The result show that the species diversity of higher plants in secondary birch forest is higher than that in broad-leaved Korean pine forest. Many of rare species existing in broad-leaved Korean pine forest are few or absent in secondary birch forest. The diversity of herbs both in broad-leaved Korean pine and in secondary birch forest is very rich and has a great change in different seasons.

Investigation of higher plant diversity in different age cutovers indicated those diversity indices of herb, xylophyta and advanced plants increased gradually in the cutovers from 1984 to 1994, and diversity indices had obviously positive correlation with richness and evenness.

The old-growth hardwood-Korean pine(Pinus koraiensis) forests in the Xiaoxingan Mts. hold a vital base in timber production in the whole country. These forests have been exploited more than 40 years and forested area and volume have been greatly decreased. The objective of the present study is to examine how to accelerate the process of stand rehabilitation or. the cutovers. The early growth characteristics of Korean pine and its regeneration on the logged area with various types of site were studied. The measures to regenerate and to grow it well have been explored in the light of the tendency of succession. This paper essentially emphasizes the fact that the artificial regeneration not only should be put into action, but the great potential of natural Korean pine reproduction should be also developed, together worked with proper treatment and sound silviculture system. It is expected that all courses of development towards the hardwood-Korean pine forest to be restored would be accelerated in the region.

After expounding the theory and feasibility of regeneration approaches of Korean pine (Pinus koraieusis) forests, the concrete measurements are put forth. There are two ways for Korean pine regeneration on clearcutting blanks: One is to keep such broad-leaved trees as birch that is naturally generated and to plant Korean pine trees with low rather than high densities so as to develop even aged broad-leaved Korean pine stands; The other is to regenerate r-strategy species with high density as transition stands at first; and then to form pure Korean pine forests through thinning. To regenerate Korean pine under canopies is an efficient approach to quicken Korean pine stands recovering, especially under such broad-leaved forests as oak stands.

According to a great deal of field investigation and detailed indoor analysis, the natural regeneration pattern and process of Korean pine population under natural Poplar-birch forest has been uncovered. The results show that the regeneration quantity and quality of Korean pine population under mountainous Poplar-birch forest and mountainous white birch forest are better than those under valley moss-grass White Birch forest and virgin broad-leaved Korean pine forest. Korean pine population shows aggregated distribution, the mass-occurrence period of Korean pine population is behind the mass-occurrence period of Poplar-birch population. Various aged Korean pines growth is affected by different stand structure factors. Man-made lighting tending can accelerate the regeneration process and increase the regeneration quality of Korean pine population. It is feasible to set up regeneration recombination of upper layer White Birch and lower layer Korean pines.

The basic principle of life table method is described, and the method of tree height instead of tree age in static life table is suggested, and it is also discussed that the possibility of natural poplar-birch forest recover to broad-leaf Korean pine forest on low pitches in the Xiaoxing’an Mountains by this method. If there is no particular situation, Korean pines after high than 5m under natural Poplar-birch forest will basically survive and make their way into dominant canopy accompanied by climax broad-leaf species.

The reference and recent working results about ecology of ash (Fraxinus mandshurica) were reviewed, which including: distribution range, suitable site, phonology, growth, photosynthesis, productivity, natural regeneration effect and mixture effect. Synthesizing above, it was suggest that the ecological characters of ash such as distribution range, limited factors, growth site etc., as well as its biology characters, features in forest, should be considered as an important basis to develop this species by different regeneration ways such as natural regeneration, artificial regeneration and natural regeneration by man-help. And experiment in artificial regeneration showed that the mixture of ash with larch has benefit to being free from or alleviating frost injury and enhancing growth

After the investigation and long-lenn research, the structure, succession, energy flow, nutrient and water cycles, productivity, etc. of Mongolian oak (Quercus mongolica) forest ecosystems are synthetically summarized. The oak, with a simple stand composition, naturally distributes at hilltops, where the soil is and and infertile and lots of tree species can not grow, and stabilizes for a long period for its high adaptive capacity and long longevity, but it will grow better in good sites. Compared with other forest ecosystems in temperate zone, the oak forest has not only more intensive biological cycles of nutrients but higher productivity as well. Among the nine elements determined, the concentrations of Ca and Zn are the highest and lowest, amounting to 41.99% and 0.0015%, respectively. In the vegetation, the largest nutrient pool is root system, making up 47.75%; and the trunk steps the following, 25.13%. Among the main secondary forest types in Maoershan region, the oak stands have not only highest biomass but best biomass structure for in which the biomass of tree stratum reaches 95.6% of the total of the stands and that of trunk does 68.9% of the total of the tree. The oak stands have high stemflow, which amounts to 15.6% of the precipitation and carries a lot of nutrients, and high evapotranspiration, which is as high as 504.1 mm and for which 77.45% of the total radiation (123.3 KJ. cm^-2) is consumed as latent heat transfer in the growing reason. The clearculting of the oak stands will result in not only increasing the surface runoff and interflow percentage but also intensifying the loses of N, Ca. Mg and Fe. Finally, it is proposed to pay a great attention to cultivating, rejuvenating and even planting the oak as high yield timber and water conservation forests.

Permanent sample plots were set up for researching interspecific relationship of the artificial larch stand mixed with natural ash in the slash site in Maoershan Experiment Forestry Farm of Northeast Forestry University. All trees in the plots were taken as objective trees and tree number, DBH, distance between trees and that of crown diameter were measured in range of 1–6m from every objective tree. Then study by Alemdag competition index, variance analysis and quantitation method were made. The result showed that the intraspecilic competition was more intensive than the interspecific competition. Especially the competition between larch and ash was least relatively For these kinds of site, the suitable mixture at 20–30 ages should be 2800 Ind./hm² in density and 2 larch: 1 ash in mixed ratio, which might improve site condition to promote stand productivity.

Differences in germination ofA. Senticosus, an important shrub under the Korean Pine broad-leavd forest and its secondary forest in heterogeneous habitats and the dynamics of its seed pool have been studied by observations in location. The results showed that transformation rates from seeds to seedlings were in the following order: 16.8% in Larch plantations, 4.1% in Mongolian oak forests, 2.7% in Birch forests, 1.8% in Korean Pine plantations, and 0.5% in hard wood forests. The life-span of seeds was determined to be four years in the simulating seed pool under Larch plantations. The percentage of the seedling output was, 14.5% in the 2nd year, 10.1% in the 3rd year, and 1.8% in the 4th year. Other types of the seed output were those: decayed 33.1%, senescent, 22.3%, predated by mice 14.1%, which was variable due to the variation in the number of mouse, and only 1.17% were eaten by insects and ofher soil animals.

Each link in initial process of artificial regeneration ofPinus koraiensis in clear cutting site was researched. The seedling recovery processes after transplantation, the affecting seedlings survival factors in different time, and the characters of seedling growth were analyzed. Results of this study suggest that the root recovery of Korean pine seedlings after transplanting is the key link in the artificial regeneration management. The synthetically management was proposed on basis of seedling root recovery process.

The artificial pure and mixed Korean pine (Pinus koraiensis) forests were investigated at Dailing Forestry Bureau in Xiaoxing’an mountains from 1990 to 1992. Depending on the distance between the samplings of Korean pine and their neighbor trees, the neighbor tree height, the size of neighbor tree canopy, and dimension of neighbor tree. The forest structure was classified into three types: (l)Growth of a tree in the light (open); (2) Growth of a tree in the canopy gap (Gap); (3)Growth of a tree under broad-leaved tree canopy. The frequency, height, and age of stem divergence of Korean pine tree were investigated by sampling trees. The temporal and spatial model of the tree growth was applied on basis of the height of stem divergence, ratio of height and DBH, and character of tree stem. The morphology and growth character of Korean pine trees during different development stage were forecasted.

Principal ideas, research approaches and installations in both Liangshui and Maoershan Ecological Stations were discussed. Significance of comparability and synchronous determination in research methods were stressed. Comparison analysis was done on the results gained from different methods. Adaptive mechanisms of Mongolian oak (Quercus mongolica) to drought and unproductive sites were expounded through hydrological cycling studies. Surface runoff and flood peak were decreased and the developing processes of flood peak were postponed or delayed because of the presence of huge forest canopy and forest floor. However, the conclusions of forest influences on total runoff, especially in spring and in the dry season t are significant to agricultural practices in northeast China and turned out contrary for watershed sizes or different approaches, which should be studied further.

Based on the data obtained by single watershed experiment, the changes in streamflow by forest fire had been studied. The results showed the most forest fire in Daxing’an Mountains in 1987 resulted in the increase of annual runoff in the initial stage, snowmelt runoff reduced in May. The relationship between precipitation and streamflow was closed. The changes in streamflow relied more on the precipitation.

Chemical and biochemical analysis methods were used to monitor the variations of nitrogen nutrient among the dominance trees species in secondary succession process of the mixed broad -leaved/Korean pine forest on Changbai Mountains, Northeast China. Amounts of total nitrogen, ammonium and NRA in soils of virgin broad-leaved/Korean pine forest which is in climax were higher than those ofsecondary birch forests those are in succession stage. The amount of nitrate was in the other hand. In climax, dominance trees species are tolerant mesophytic trees such asPinus Koraiensis, Tilia amurensis, Acer mono and alsoFraxinus mandshurica, they are all ammonium + nitrate adapted species, but they show a preference for the ammonium rather than those of the pioneer trees species in secondary birch forest, such asPopulus davidiava andBetula platyphylla. Because they have more ammonium in their leaves and roots, especiallyPinus koraiensis. Populus davidvana andBetula platyphlla are intolerant trees, amounts of nitrate and total nitrogen is higher in their leaves and roots and also NRA in their leaves, so they preference for the nitrate rather than the others. In secondary birch forest, the regeneration trees species adapt their nitrogen nutrient to the variation of nitrogen nutrient situation in soil, finally they could survival well and the secondary birch forest would succession to climax. In climax, dominance trees species adapt their Nitrogen nutrient to the situation in soil and there are not strong competition in nitrogen nutrient among them, so they can coexist well and keep the climax as stable vegetation.

The yield increasing mechanism of the manchurian ash (Fraxinus mandchurica) and dahurian larch(Larix gmelini) mixed stand was studied on nutrition status of soil and leaves. The results showed that nutrient contents of leaves and contents of the available nutrients of soil in the mixed and pure stands varied with seasons of the year. The available phosphorus contents of the soil in the larch belt were much higher than those in the manchurian ash belt during growing season, with the highest value of 3.5 mg/100g, 2–3 times of the latter. The nitrogen contents of leaves of the manchurian ash trees nearest from dahurian larch belt were 12.7%–80.8% higher than those of its pure stand, and phosphorus 13.4%–140.8%. The different uptake rhythm of the nutrients modified the interspecific competition. The general conclusion is that the high contents of available phosphorus of the soil in dahurian larch belt improved the growing condition of nearby manchurian ash trees.

The characters and effects of available phosphorus in dahurian larch-Manchuria ash mixed stand was analyzed through measuring available phosphorus of rhizosphere-soil, phosphorus of living and withered leaves and tree height. The study results showed that the phosphorus of living leaves of larch was equal to or less than that of ash. For 5-year-old larch-ash mixed seedlings stand, larch has more available phosphorus in soil, which is not caused by the decomposition of leaves, but the acts of root. The root of larch activates available phosphorus by acidoid fine rhizosphere-soil. At the site with a high concentration of available phosphorus (growing bean before), 5 aged larch grows faster than the same aged ash in pure stand. The ash at the site with a high concentration of available phosphorus at 20 cm soil layer showed a trend to grow over larch, and at the site, with a low concentration of available phosphorus at 20 cm soil layer, had a trend to be suppressed by same aged larch.

Based on a large number field investigation and experiment inlaboratory and the corresponding qualitative and quantitative analysis, 6 fuel type groups and 12 fuel types were classified to the east mountains in northeast China in this paper. The characteristics, distribution and fire behavior of these fuel types are also widely discussed.

Based on the great field investigation and experiment in laboratory, four fuel types were classified for all broad-leaved/Korean pine forests and its plantations in northeast China in this paper. Various kinds of fuel loads, combustibility and potential energy are calculated and discussed. The relationships between fuel types, fire environment and fire behavior are also widely expounds, and some research results and management suggestion on Korean pine forests are also given in the paper.

The paper concerns objects are the functional leaves ofPopulus davidiana three years old in natural environmental. We discuss mainly the structure, function, motional law of the ecological boundary and its ecological effects.