By taking soil samples from field at different soil depth in different undestroyed forest soil in the Natural Preserve Region of Changbai Mountain, measuring their saturated conductivity and effective porosity, we put forward logarithmic submodels that saturated conductivity and effective porosity vary with depth. Then, substituting those submodels into Sloan's storage-discharge model, a simple modified storagedischarge model of interflow based on the balance of water and kinematic assumption was presented in this paper. The interflow processes of two rainfall events were simulated separately on a simulated hillslope of forest catchment in Forest Hydrological Modeling Laboratory of Changbai Mountain Forest Ecosystem Research Station, Chinese Academy of Sciences, and the modified model was tested and verified by comparing the hydrograph of interflow predicted by the model with measured hydrograph. The simulated hillslope used the hillslope of broad-leaved Korean pine forest in catchment of Erdaobai River as background. At the same time, we compared our model, Sloan's model and Robinson's model with the measured results simultaneously, too. The results of comparison show that our model is better than the others, especially, our model yields excellent results at simulating total volume of interflow, peak time, peak flow, and delay time.

The stand productivity, soil fertility under the management pattern of planting 30-year-old Chinese fir with keeping broad-leaved trees (PCKB) and pure Chinese fir stand (control) were studied. The results indicated that the tree size of Chinese fir in PCKB was bigger than that of the control. The stand total volume of PCKB was 11.35% higher than that of the control. Compared with the control, the soil structure and moisture condition were improved, the activities of soil biochemistry and the activation of soil humus strengthened, the amount of available nutrient supply and the amount of soil microorganism increased. The soil fertility was improved obviously and it promote tree growth of PCKB stand.

Mitochondrial (mt) coxI, atp6 and orf25 DNA fragments for 12 species, which belong to two subgenera Pinus and Strobus of the genus Pinus, were amplified by polymerase chain reaction using gene specific primers. Their partial sequences were obtained by directly sequencing the PCR products with the same sets of primers. No sequence difference in coxI was observed among 12 species. However, nucleotide substitutions in both atp6 and orf25 between and within two subgenera were found. These results indicated that the variation of mitochondrial gene sequences were gene dependent, although the intensive RNA editing existed in mitochondrial genome could stimulate the divergence of the genomic DNA sequences. The phylogenetic trees of 12 species using atp6 and orf25 sequences agreed with their taxonomy positions, and the genetic relationships between the species within each subgenus were resolved additionally. This suggests that the mitochondrial gene sequences can be used in the phylogenetic analysis below the genus level in gymnosperms.

The effective meiosis period and treating duration of pollen chromosome doubling were researched, based on mastering the meiosis law of microsporocy te of Populus tomentosa ×P. bolleana. The results indicated (1) A certain proportion of the bigger pollen grains could be gotten from the male flower buds induced by cochicine solution, the highest proportion was up to 88% and these bigger pollen grains contained 38 chromosomes by microscopic examination, and could normally germinate by both the common medium and the vivi-fertilization; (2) Generally, so long as the buds were cultured with water for 40 hours, the colour of anther changed from light green to yellowish-green, not to get red, i. e. during the period from the end of bouquet stage to the beginning of diplotene, in which the best doubling effect could be obtained. (3) During the suitable treating duration, there was correlation between the treating frequency and the amount of obtained pollen, considering the 2n pollen ratio and the amount of obtained pollen, the better treating frequency was from 3 to 5 times, the interval between two treatments should be 5 ~ 7 hours.

The genomic DNA variations of J. hopeiensis、J. mandshurica、J. regia、J. hidsii ×J. regia and J. regia ×J. mandshurica were analyzed using random amplified polymorphism DNA(RAPD) in the present study. Twenty-eight decanucleotide arbitrary primers generated 332 RAPD bands with the size ranging from 259 bp to 3054 bp, 243 of these bands were polymorphic (73.2 %). The similarities and genetic distances among them were analyzed with Jaccard's and Nei's methods respectively. The dendrogram based on the genetic distances supports the hypothesis that J. hopeiensis originated from the nature hybrid of J. regia and J. mandshurica. In addition, the J. mandshurica gave more genetic contribution than J. regia to the hybrid. Therefore the J. mandshurica is suggested in the Sect. Cardiocaryon, which agrees with the conventional taxonomic position.

The graft tests were performed under the sterile and in vitro cultured conditions using infected plantlets with phytoplasmas and seven phytoplasma-free clones of Paulownia spp. displaying different degrees of natural resistance. DAPI fluorescence microscopy and polymerase chain reaction(PCR) based on the phytoplasma 16S rRNA gene sequence were taken for the pathogen detection. The result indicates that the graft transmission of phytoplasma from diseased scion to healthy rootstock or from diseased rootstock to the healthy scion is a new efficient way to evaluate the resistance of Paulownia against phytoplasmas as well as to acquire infected clone materials. The clone C125 and XuH demonstrated strong necrotic reaction along the stem of the inoculated rootstocks from graft joints, ZH and T35-028 with moderate degree of necrosis, while QLM, C020 and C161 with slight reaction. Plant growth regulators(6-BA, NAA) added to MS medium reduced the necrotic effects, therefore increasing graft efficiency, while salicylic acid(SA) in the medium, or the removal of the roots and leaves from inoculated rootstock aggravated it. The reliable graft of diseased scion on QLM rootstock showing natural resistance did not induce witches' broom symptoms on QLM rootstock, despite the fact that pathogens were detected in the grafted rootstock plantlets by PCR. However, by grafting healthy QLM shoot on diseased rootstock, QLM scion was likely to develop typical witches' broom symptoms, which indicates some correlated resistance with that of roots or mature leaves. The phytoplasmas were graft-transmitted into all clones, except C125, and induced indistinguishable witches' broom symptoms to one another. In the phloem of infected tissues of each clone, the bright autofluorescence accumulated gradually, with the development of symptoms; and the intensity of the autofluorescence was correlated with clone's resistance to some extent

The bark beetle species on Pinus armandi and their niches were studied in the middle areas of Qinling Mountains. The results showed that 19 species of bark beetles infecting and damaging Pinus armandi in pine ecosystem of Qinling Mountains were found, but only 11 species of them could be competitive and coexistent one another. Although each of the 11 species of the bark beetle had its own spatial niche and overlogs niche, they could attain competitive equilibrium and coexistance according to their requirment for different nutrition and space, the interference of population density and the different time interval attacking the host tree. In the construction of the ecosystems of bark beetles on Pinus armandi in Qinling Mountains, the bark beetles first attacked the healthy tree, carrying the blue stain fungi into it, quickly weakened the trees vigor, then the mainly secondary bark beetles Ips acuminatus, Pityogenes japonicus and Ips sexdentatus attacked the weakened trees. Finally, other bark beetles infected to the withered trees, and utilizing the surplus spatial niche and trophic niche of the host trees. Consequently, the relatively steady ecosystem of the bark beetles on Pinus armandi could be constructed.

The precent paper reports that the hybridization could be easily done between Masson-pine caterpillar, Dendrolimus punctatus Walker(1858), Korean-pine caterpillar, D.spectabilis Butler(1877), Larch caterpillar, D.superans(Butler) (1908), and Chinese-pine caterpillar, D.tabulaeformis Tsai et Liu (1962).Except Larch caterpillar, whether direct cross or reciprocal cross could produce a fertile filial generation (F₁) respectively, which selfing to F₂ generation, so they were identified to be of the same species, more correctly as a subspecies, for in consideration of there to be some differences in morphological and ecological features, and accoding to the International Code of Zoological Nomenclature and regulations concerned, i.e.the Korean-pine caterpillar is a subspecies of the Masson-pine caterpillar, Dendrolimus punctatus spectabilis (Butler) as the Chinese-pine caterpillar, Dendrolimus punctatus tabulaeformis (Tsai et Liu).While as the larch caterpillar with them, the process of crossing was often foiled, or its hybrid, F₁ generation with higher mortality and ofter went into diapause, and after selfing the F₂ generation was not obtained so far, the genetic relationship between the Larch caterpillar and other species needs to be proved further.

A new R-Ⅱequation infered from the heat equation of prerignition int roduced by Rothermel(1972), was given as follows:△Q=H(1-M_f)-4.1816M_f△T_b-2256.68kM_f - 1.599△T_g(1-M_f) where△Q-Net heat value released per kg of fresh fuels; △T_b-Difference between 100 ℃ and atmo-spheric temperature; △T_g-Difference between fuel ignition temperature and atmospheric tempe rature; H-Gross caloric value of fuels; M_f-Moisture content of fuels; k-Ratio of the evaporation capabilty of pure water to that of the water contained in different fuels. Our equation was used to calculate and classify the aloric value by fuels made from 40 kinds of trees and 8 shrubs. The ca lculated net heat values provide an important index for the evaluation of trees resistance to fire. According to the R-Ⅲ equation, the combustion of all woody plants studied can be classified into 3groupe more resistant plants (3590 kJ, 13 spedies), moderately resistant plants(3590 ~ 5822 kJ, 19 species), and poorly resistant plants(> 5822 kJ, 16 species). The species with the lowest combustion values such as Idesia polycarpa, Cratagus pinnatifida, Poqpulus davidiana, Acea davidi, Ligustrum lucidum, Betula luminifera, Populus tomentosa, Juglans regia, Magnolia denudata, Picea wilsoni, Salix matsudana, Plantycaryar strobilacea, Rhus verniciflua, can be selected for use as fire resistant tree plants.

The contributivity of solid wood properties to LVL strength can measure how much LVL strength is originated from solid wood properties.The proportion of end-use selection and their difference values, which were calculated by contributivity between solid wood and LVL, were used to judge the enduse selection of plantation poplar as solid wood or LVL in this paper.The results showed that the different values of Poplar 69, Poplar 72, Poplar 63 were 57 %, -15 %, -29 %, respectively, and indicated that Poplar 69 was suitably used in solid wood, Poplar 63 and Poplar 72 in LVL.When 3 kinds of LVL were assembled with veneers of 3.565 mm, 2.614 mm and 1.545 mm in thickness, their differences were 43 %, -13 %, -43 %, respectively.These indicated that poplar was suitably used in solid wood compared with LVL with thick veneers, but in LVL compared with LVL with thin veneers.In addition to all of 6 properties, poplar was suitably used in solid wood to the properties of shear strength, modulus of elasticity and impact toughness because of their positive differences, but in LVL to the properties of modulus of rupture, compressive strength and hardness because of their negative differences.

Results from the measurements of vascular bundle density and fiber coverage, and the tests of density, moisture content, shrinkage, tangential bending strength and longitudinal compressive strength showed that the textures and physical and mechanical properties of four typical thick-growing structural bamboos in Yunnan, Dendroncalamus giganteus, D.brandisii, D.membranaceus and Bambusa lapidea, are quite different from not only among the species but also the positions within a bamboo pole along the radial, tangential and longitudinal directions.Compared with the vascular bundle density, the fiber coverage should be more appropriate to reflect the relationships between the textures and the physical and mechanical properties of the bamboos.It was found that the relationships between the fiber coverage and density, tangential bending streng thand longitudinal compressive streng thare direct, but the relationship between the fiber coverage and the full moisture content is inverse.

Hot spots analyses afford theoretical basis for us to make strategies and determine different classes of biodiversity conservation for different places.Mainly because of heavy human perturbations, many species and ecosystems in the world are in endangered plight.The loss of biodiversity in tropical rain forests are most serious.Although hot spots occupy very small part of the earth surface, they own a large percentage of the global species pool.Special attention should be paid to biodiversity loss of these regions. The extinction vulnerability of different species is different.Rare species and long lived species are especially vulnerable to extinction.As for keystone species, once endangered, many species which depend on them will likely go to extinction.The loss of genetic diversity is an important aspect of biodiversity loss.The loss of genetic diversity in population are mainly due to founder effect, demog raphic bottleneck, genetic drift and inbreeding.Species conservation should include conservation for genetic diversity in species.Mechnisms of population dy namics and source-sink population dynamics have important implications for biodiversity conservation.Population viability analysis is a new method to understand mechanisms of species endangering.Interrelationships of species in communities and natural disturbance regimes are important aspects to be considered in the conservation of biodiversity.Human caused habitat fragmentation is different from the heterogeneity of natural landscapes.Habitat fragmentation may cause a series of biological effects such as edge effect and crowding effect, etc.

This paper reviews research achievements about biological fo rest fire control, states selection and application of fire-resistance tree species, and discusses the current advances in the technology of establishing firebreaks and mixed plantations.The firebreaks play an important role in forest regions of southern China and will more widely be applied in the future.More research will be needed in the mechanism of firebreaks, both quantitatively and qualitatively.The architecture of firebreaks should be built up with multiple tree species and in complex structure.Meanwhile, integrated management of forestry should also be encouraged.

Over the past 20 years,many efforts have been expended to elucidate the structure of ureaformaldehyde (UF)resins for obtaining more effective UF resin adhesives with optimized strucutres.Several modern analytical tools and techniques have been applied as they become available.Fourier transform infrared spectroscopy (FTIR)and ¹³C nuclear magnetic resonance(¹³CNMR)are the most useful and powerful tools.Characterization of the structure of UF resins by ¹³C NMR of their solution is well established and is the most important technique,and it is the best method at molecular level of characterizing and documenting the variations in resin chemistry for UF adhesives.This paper gives a review on history,methods and results about the study on the structure of UF resins.

Forestry classification management is an important measure for forestry reforming which is put forward by Ministry of Forestry. How to classify Commercial Forest(CF) and Public benefical forest (PB) scientificly and rationally is the problem to be solved urgently for forestry classification management. The paper approaches the subjects of the forest functional classification system, PB and CF classifying index system and technical standard from the systematic, feasibly and scientific angles. According to forest dominant functions, forests are classified into two groups of PB and CF, five subgroups and 21 forest types from three levels. Two complex indexes of ecological fragility class and ecological importance class are used by PBF. The classification index system of CF is consisted of four indexes, invest profit, net value, forest volume increment and site convenience class. The technical criteria are determined according to the forest types.

Based on the climatic data of 40 representative plots in the distribution area of Pinus bungeana Zucc., the distribution area can be divided into 6 climatic regions: the North, the West, the middle, the south-middle, the south-west and the South respectively by the method of PCA(principle components analysis) and ISODATA cluster analysis. The results show that in the distribution area of P. bungeana Zucc., the geographical locations of different climatic regions are discontinuous and the differences of climatic condition among the regions are very significant. The growth pattern of trees and distribution trends is related to climatic condition closely. Furthermore, the typical picking sites for provenance test are selected.

Permanent sample plots were located in solonchak area in Hetao Plain, Inner Mongolia. The water-salt movement was observed in unfreeze periods during 3 years, and over 400 soil and ground water samples were measured. It is found that the dynamics of salt in soil can be divided into following stages: evaporation-salinization stages in spring and autumn, leaching-desalinization stages in summer(because of rainfall and irrigaiton), and relative stable stages in winter. The fluctuation of ground-water table was closely related to the water amount of irrigation. Mineralization of ground-water and pH value was rather stable. Salt accumulation in the top soil layer of solonchak was existed in experiment area over the years.

Mechanical injury or pathogen and insect invasion usually involves a seties of defence-related gene expression in plants, Some of these genes show distinct wound-inducibility.One of the wound-inducible win3 multigene families from hybrid poplar, encoding a protein similar to sweet potato sporamins and legume trypsin inhibitors, was previously isolated by Bradshaw et al.(1989).To further understand the role of its upstream regulatory region in wound-mediated response, and its possibility to be used in geNetic engineering for the control of the expression of foreign genes, the win3 gene promoter WINP(705bp)and WIDP(791bp)were amplified from P.nigra and P.deltoides, respectively.Both promoters were fused to the E.coli β-glucuronidase(GUS)reporter gene, and introduced into tobacco plants by virtue of Agrobacte rium-Ti system.This study demonstrated that GUS expression responded to wounding locally and remotely in transgenic tobacco under the WIN(D)P control, and the biochemical and histochemical assays of GUS activity for 8 transgenic lines gave the similar expression pattern as reported by Hollick et al. (1995).It was also observed that the responsibility to wounding of WINP was always stronger than that of WIDP, both on the injured or uninjured sites.Further modification of both promoters is necessary to increase their ability to enhance the expression thus to be used in genetic engineering to obtain wound-inducible expression of foreign gene(s).

The green environment will produce a positive effect on the human health. It is the purpose of this experiment to quantify the effect. By means of physilogical reactions of selected groups in different green environments, such as urban district of Beijing and National Mangshan Forest Park, we strive to obtain the quantified index of environmental quality in medicine.

The paper firstly describes the basic concept of GPS and its technique. Then a differential GPS used to monitor and control forest insects in CAF is introduced, and experimental results are given. Experiments show that the GPS technique have great potential in forest resource management. Finally, some suggestions to apply the GPS technique in forest production are given.

This paper presents the reliability design method of driveaxle housing for forestry mechanary. On the condition that the probability distribution of the basic random variables is given, an effective and practical method for this design is put forward with the technique from perturbation method and reliability design theory. The theoretical formulae of the reliability design are induced. The correspondin computer program is made and can be used to accurately and quickly obtain the parameters of the reliability design of driveaxle housing.