Comparing with an affinity and widespread speciesAdenophora potaninii, the age structures of A.lobophylla population, an endangered plant species were studied. 29 sample plots were investigated in the centered distribution area, Jinchuan county from altitude 2 300 m to 3 400 m. The main factors which influence the population age structures of A.lobophylla were analyzed. The principal characteristics of A.lobophylla populations are that the number of seedling and the density of population are much less than these of A.potaninii population. Below altitude of 2 700 m, the age structures of most A.lobophylla populations show the declining status, only above altitude of 2 700 m they are stable, while age structures of all populations of A.potaninii populations at corresponding altitude perform stable and developing features. The age structure patterns, relations between age (x) and number of individual (y) of stable populations of A.lobophylla can be expressed by equation: y =e(^a-bx), and the longest life span is 25a. Whereas A.potaninii populations can be expressed by the equation: y =ax^-b, and the longest life span of individual is 21a. The external factors, which constrain the extension of A.lobophylla population, are extreme environmental conditions such as serious drought, external disturbance and low temperature.

In this paper, root-shoot relationships of seedlings of Manchurican ash (Fraxinus mandchurica) in pots is studied in green house. The results show that roots and shoots have the co-ordination of growth and roots and shoots of ash have the same growth dynamics. There are very close relationships between total root mass and total shoot mass, between fine root mass and leaf mass in this experiments. At the end growing season, ash root-shoot mass ratio and fine root-leaf mass ratio are 1.85 and 2.01 respectively. These ratios are difference during growth season. There are larger roots than shoots on seedling stage. Low nitrogen and phosphorus produce higher root-shoot ratio, and high nutrient concentrations decrease the ratios.

Conditions have been established for the callus initiation and subculture ofT. chinensis. The calli were induced by the explants cultured first on the medium MS supplemented with 1.0 mg/L 2,4-D, 2g/L CH, and 25g/L sucrose, then on The medium: MS+1.0 mg/L NAA+0.5 mg/L BA+2g/L CH+25g/L sucrose. When the callus was subcultured and tamed several times, it could grow fast and stable on the medium: MS+0.2mg/L 2,4-D+0.5 mg/L NAA+0.5 mg/L BA+2g/LCH+25 g/L sucrose. The contamination of explants was a result of endophytic microbes ofT. chinensis. This could be avoided by adopting the tender shoots 3–5 cm long collected in early spring as the source of explants. The browning of the cultures could be prevented and controlled by means of the selection of a suitable explants, hormonal regime in the medium, culture methods and the use of antioxidants.

The paper presents the results of biometrical study of the seeds and cones of larch taxa from Northeast of China. Fourteen characters are considered and their analyses showed that the seeds and cones of the larch taxa were relative greatly variable. Cluster analysis and principal component analysis for all 6 larch taxa were made. The analysis results proved that the dominant larch population in Toudao Farm fell within the range of variation ofLarix olgensis. The key taxonomic characters are the length of seed wing, length of cone, length of seed, the length/width ratio of seed and number of scales.

Many methods of restoration and rebuilding of forestry ecosystem were used, because the function of the secondary broad-leaved forests declined. One of these methods was the artificial regeneration carried out with gap technique in the forest. The results showed that the communities had been getting to Korean pine forests mixed with broad-leaved trees and the speed of development was much faster than before.

In this paper a general introduction is given to research advances in genetics improvement and breeding of Chinese aspen (Populus davidiana Dode) in China. This introduction includes natural distribution and collection, conservation, gene diversity, provenance trial, crossing breeding, vegetative propagation and disease resistant etc. Based on the current situation of forest tree breeding in China, some strategic suggestions concerning the future development of Chinese aspen genetics improvement in China are presented, taking into consideration the existing domestic demands of forestry production and international trends in forest tree breeding.

The ornamental characters, nutritious composition, edible value and medical value of thirteen kinds of major wild fruit resources in Xiaoxing’an Mountains Region were synthetically analyzed such asRosa spp.,Actinidia spp. and so on. The results showed that the wild fruit resources in this region had important garden ornamental value, edible value and medical value. A lot of good germplasm resources and honey plant resources hadn’t been effectively protected and enough utilized. The right way of appropriate arrangement and reasonable exploitation of wild fruit resources in this region should be benefit to get rid of economic crisis early in this region.

Faced with the conflict between the environmental protection and timber production, the concept of new forestry and the effect of new forestry objectives on existing harvesting techniques and equipment have been introduced. Adaptive management—a help tool for developing new harvesting techniques and equipment has been proposed. An adaptive approach for developing a forest harvesting for new forestry should be composed of careful planing, considerable hypotheses, detailed testing and evaluating as well as correct and fast feedback. New forestry practices are by no means easy because the complexity of the problem and almost every thing is new. We will see more successful new harvesting techniques and equipment being developing by adaptive approach for new forestry in the future.

The growth of ash (Fraxinus mandshurica) in different mixed stands with larch (Larix gmelini), Korean pine (Pinus koraiensis) and spruce (Picea koraiensis) had been investigated. Meanwhile, the relationship between the growth gain of mixed stand and topographic factor, and the growth comparison of ash in pure and mixed stands with different age-stages were presented in this paper. The results show that the effect of ash and larch mixed stand is very significant. The growth gain of ash in mixed stand on east slope is better than that on west. The growth effect is the most significant on east upper slope and on west down slope. The growth of ash can be increased significantly during different age-stages, but of Larch only through its occupying dominant position in above-ground competition.

The relationship between the change of forest resources and climatic factor in the, “Three-North” region of China were studied in this paper. The predicting equations of climatic factor (dependent variable) with regional independent variable (longitude, latitude and altitude) and stand independent variable (forest coverage rate), were developed by extensively using the linear and nonlinear regression methods. With these models, we can calculate the ecological benefit of Shelter-belt forest.

The biomass of spruce (Picea koraiensis) plantation in the Suiling district of Heilongjiang Province was systematicly studied. Net productivities and their distribution biomass of the stem, bark, branch, leaf and root on the arborous layer of spruce plantation from 6 to 31 a were investigated and stem analyses using mean sample method. The regression equations for estimating the biomass of different organs of individual trees were set up. The result showed that the biomass of stand was 151 t/hm⁻² and net productivity was 11∼14 t/(hm^2·a).

The microscopical observation and karyoltype analysis of embryo root cells of healthy Xingkai Lake pine and Xingkai Lake pine infected byCronartium quercuum were conducted. The results showed that the dividing phase of embryo root cells decreased and the viscidity of cells in dividing phase increased when Xingkai Lake pine was infected byC. quercuum. The karyoltype changed from the contract 4A to 4B, but the number of cell chromosome and karyoltype component did not change.

This paper reports the histological observation of larvae ofZethenia rufescentaria Motsch. after infection by ZrNPV. Histopathologic study revealed that ZrNPV were multiplied within the nuclear of fat body, epidermis cell, midgut cell, tracheal matrix and blood cell. These cells showed obvious cytopathic effects. The nucleus of infected cells underwent swelled. Under electron microscope, virus and polyhedral of ZrNPV were clearly observed in these nucleus of infected cells. The nucleus of susceptible tissues were fulfilled with polyhedra after 70–140 h.

The Daxing’an Mountains and Hulunber Grassland are located in the northeastern border area of China. This region covers a large area of rich biodiversity. The natural environment here is well protected because of low pressure of human activity. There are 5 species of cranes here. They are Red-crowned crane (Grus japonensis), White-napped crane (Grus vipio), Siberian White crane (Grus leucogeranus), Grey crane (Grus lifordi) and Demoiselle crane (Anthropoides virgo). Red-crowned crane is a breeding species that is widely distributed in this area. The main breeding population of this species is in Heilongjiang Province. They migrate to the south of China in winter. White-napped crane, Grey crane, Demoiselle crane are also summer birds. It remains unknown if Siberian White crane breeds here. Since the population of Red-crowned crane, White-napped crane, Siberian White crane in China are at the edge of endangering, so they are listed in the namelist of national protected species. But Grey crane, Demoiselle crane have a larger population, and are widely distributed.

The constituents of essential oil of Asternovi-belgii were analyzed by GC and GC/MS. 18 peaks were separated by GC and 14 compounds were identified. The identified constituent’s accounts for 99.10% of GC peak areas of essential oil. The major chemical constituents of Asternovi-belgii are β-Pinene (38.33%), α-pinene (31.23%), and thujene (16.71%).

Experiments on spaying Penzhangjing on seedlings ofLarix leptolepis was conducted for a year. The height growth and diameter at foot of experimental seedlings increased by 34.3% and 35.5%, respectively, compared with control seedlings. Variance analysis concludes that Penzhangjing have obvious effect on growth of height and diameter at foot of seedlings.

The log float technology from timber depot at the reservoir to log feeding rolls was studied by model tests. The model test was taken with the rule of gravitation similitude and ratio of 1∶10. Main parameters, like the amount of tug boats, hydro-accelerators and the structure of feeding rolls, were determined. The more suitable float process is put forward and the reliable basis for the design is supplied.