Wang Qing-li

Relationships of climate change and tree ring of Betula ermanii tree line forest in Changbai Mountain

Based on the tree-ring growth characteristics of Ermans birch (Betula ermanii charm.) and the relationships between it and climatic factors at elevation of 1950m, the sensitivity of tree lines in Changbai Mountain to climatic factors was assessed. The results indicated tree line forest in Changbai Mountain had an obvious, sensitivity to climate factors. However, difference from other study sits is that the main climatic control factor on tree-ring growth was not current growth season temperatures, as might be expected, but previous winter and current March temperature. Although the precipitation in the region was quite abundant, the tree-ring growth was still significantly correlated with the precipitation during previous winter and current spring. Additionally, climatic factors which influenced the Ermans birch growth were not the yearly variables, but seasonal and monthly variables. Therefore the reported increase in yearly mean temperature and total yearly precipitation since 1980s was not responded by sustained increase in ring widths in recent decades.

Effect of soil moisture gradient on structure of broad-leaved /Korean pine forest in Changbai Mountain

A 112 m×8 m sample pot which includes 14 sub-plots was set up along the slope in Hongshi Forestry Farm of Baihe Forestry Bureau (127°55′E, 42°30′ N), Jilin Province in August 2002. Community structure, soil moisture contents at 0–10 cm and 10–20 cm in depth, water content of litter as well as the contents of C, N and P of litter, living leaves and branches in the broad-leaved/Korean pine (Pinus korraiensis) forest were measured in each sub-plot on different slope positions. The analytical results showed that there existed an obvious soil moisture gradient along the slope: upper slope <middle slope< lower slope. The difference in soil moisture contents on different positions of slope led to a change of the stand structure of the braod-leaved/Korean pine forest. The proportion ofQuercus mongolica gradually increased with the decrease of soil moisture content and that of other major tree species in the broad-leaved/Korean pine forest gradually decreased or disappeared. The dynamic of soil moisture contents in the litter layer was as same as that in mineral soils. The decomposition rates of the litter on different slope positions were different and the dry weights of existent litter varied significantly. The soil nutrients in the litter on the lower slope was richer than that on the upper slope due to the different stand structure on the different slope positions. The moisture content and nutrient contents of soil had effects on the composition, decomposition, and the nutrient release of litter, thus affecting stands growth and stand structure and finally leading to the change of ecosystem.

Species frequency of communities along northern slope of Changbai Mountain, Northeast China

The species distribution frequency of communities from 700 m to 1900 m along northern slope of Changbai Mountain was studied by using Raunkiaers frequency analysis methods in summer of 1999. The variation on composition and structure of communities with the increase of elevation was displayed from the point of view of frequency. The results showed that for all the species of community including tree, shrub and herb, the frequency presented a “L” shape even though there were difference among communities. The percentage of high frequency species increased with the increase of elevation. As one of important index in reflecting species spatial patterns, frequency not only show up the importance of species, but also the evenness of spatial distribution in community. Frequency figure could reveal the complexity and diversity of community at some extent.

The changes of co-possession of plant species between communities with altitudes on northern slope of Changbai Mountain

Twenty plots were investigated on northern slope of Changbai Mountain at an attitude interval of 100 m (from 700 to 2 600 m). The species co-possession between plant communities at different altitudes was analyzed by Jaccard index. The analytical results showed that the co-possession calculated according to species in different layers or all species between adjacent communities was higher than that between disjunct communities. The co-possessions between adjacent communities calculated by species in different layers had comparability and dissimilarity. If the two adjacent communities belong to different types of vegetation, then their co-possession was lower. The peak values and valley values of species co-possession between communities along elevation gradient just matched vegetation gradient patterns, and species subrogation of shrubs had more obvious rule on northern slope of Changbai Mountain. Co-possessions between communities with same altitude difference were much similar, and it decreased as the increase of elevation difference, which showed that species compositions in different layers of the communities were highly related.

Study on height growth model ofPinus koraiensis

Growth model is an efficient way to study growing process of some factors of plants quantitatively. Height growth of Korean pine (Pinus koraiensis) was studied by using Hyperbola equation, Logistic equation, Richards equation with three parameters, and Richards equation with four parameters in this paper. The results showed that Richards equation with four parameters was the most suitable and could be turned into other theoretical equations when some parameters were given different value. The maximum height of trees could be given in advance when using Richards equation with four parameters, and it was even more corresponding to reality. In addition, a height growth model with real height of fixed age as a parameter was discussed in this paper. This kind of growth model could be used to calculate height growth of a given tree effectively.

Dynamics of dominant tree species in a forest ecotone on the northern slop of Changbai Mountain

The competition and dynamics of dominant trees species in the forest ecotone between the broad-leaved/Korean pine (Pinus koraiensis) mixed forest and the spruce-fir forest (also known as dark conifer forest) in Changbai Mountain, Jilin Province in Northeast China were studied by using Lotka-Volterra model, based on the data from twenty-eight sample plots with area of 20 m×90 m for each one. Results showed that under natural condition, differentiation of communities followed two directions: one would be Spruce (Picea jezoensis and few P. koraiensis) and fir (Abies nephrolepis) co-dominant conifer forest, and at the equilibrium fir was absolutely preponderant (77.1% of relative dominance (RD)); the other would be the confier and broad-leaved mixed forest, and at equilibrium, the broad-leaved tree species was 50% of RD in the broad-leaved/Korean pine mixed forest and 66% of RD in the broad-leaved and spruce-fir mixed forest. The study demonstrated that both broad-leaved/Korean pine mixed forest and dark conifer forest were climax community, the ecotone had transitional characteristics, and the diversification of the forest communities suggested that the direction of succession was affected by local habitat.

A preliminary study on in-stream large woody debrids in broadleaved and Korean pine forest in Changbai Mountain, Northeast China

This study was conducted in Erdaobaihe River passing through the broadleaved and Korean pine forest located on the north slope of Changbai Mountain. In-stream large woody debris (LWD) in two segments of the river channel was investigated with base diameter, top diameter, length, and decay class. To study relationship between in-stream LWD and adjacent riparian forest, species of each log of LWD in segment 1 was identified, and the riparian forest was examined by setting a 32m×24m quadrat consisting of twelve 8m×8m small quadrats. The results showed that, in segment 1, in-stream LWD loading was 1.733 m3/100m or 10.83 m3·hm−2, and in segment 2, it was 1.709 m3/100m or 21.36 m3·hm−2. In-stream LWD in decay class III and IV were accounted for a high proportion, which was different from that in the broadleaved and Korean pine forest, and the possible reason might be different decomposing velocities due to different decomposing conditions. Logs of LWD in stream and living trees in riparian forest declined as diameter increased, and it was in a reverse J-shaped distribution except logs of LWD in segment 1 in the first diameter class. Volumes of LWD in stream and living trees in riparian forest increased as diameter increased, and it was in a typical J-shaped distribution. Loading and species component of in-stream LWD were correlative to status of riparian forest to a certain extent, and there also existed difference. Comparing the correlation and difference was helpful to study on dynamic of the riparian forest.

Ecosystem management and forestry

In this paper, the conceptions and developments of ecosystem and ecosystem ecology were reviewed and summarized. Then, the conception, connotation, objective, and development of ecosystem management were expounded. Based on these discussions, forest ecosystem management was discussed. The viewpoint was that the former unreasonable forest resources management should be changed and forest ecosystem management was a suitable way to sustainable development of forestry. The chief research contents were also pointed out in this paper.

On forest ecosystem health and its Connotations

This paper cursorily introduced some ideas and approaches of ecosystem health researches. The definition and connotations of forest ecosystem health have also been expatiated. Defining forest ecosystem health has been discussed from the management objective approach, and integration approach. To impel the relative researches in China, more attention on the properties of a forest ecosystem should be paid.

Review of forest ecology studies in China

As the most important type or component in the terrestrial ecosystems, forest ecosystem makes its role obviously prominent and important on environment and human being. It possesses non-substitutable functions in the process of sustainable development. However, due to the complexity of the forest ecosystem and the relatively delay or lack of the related research technology, the science is still in the case of immature and questions. This paper summarized and reviewed briefly the development and the present case of the forest ecology, then pointed out the existing problems in the forest ecosystem researches. In the end, we discussed several fields that need to pay more attention to in future researches.