Dynamics of concentrations of organic free radicals (OFR), content of Vc and activity of SOD was monitored for overwintering needles of Pinus sylvestris var. mongolica and Picea koraiensis in the Changbai Mountain. It showed that the patterns of variation in concentrations of OFR in needles of Pinus koraiensis differed clearly from all other tree species, which was closely related to the severe photoxidation injury. The maximum peaks of Vc content and SOD activity of needles were found that during winter they played an important role in protecting needles from the injury induced by free radicals. SOD activity of Pinus koraiensis needles was much lower than that of Picea koraiensis, which was probably the important reason for susceptible photoxidation injury in winter. The relations among freezing, light and oxidative stress were discussed in terms of free radicals and scavengers.

The leaves of Ammopiptanthus mongolicus possess dense epidermal haires,thick cutides,close connection of epidermal cells,and well-developed palisade tissue,but few spongy tissue.The tonopalsts of the palisade cell often occur a large amount of endocytosis to form various membrance-shaped structures in the vacuoles, some of them happens with near cytoplasm, vosicles, as well as endoplasm reticulum together to form cytolasm protuberance which further develops into cytolasm band. Therefore, the vacuoles are broken up continuously, the volumes of vacuoles get smaller and smaller, and the numbers and scattered degree increase greatly. The small vacuoles are rich in granular and fibroid substance, but no many membrance-shaped structures are found.

In this paper, a new method was proposed for sit information, which was applicable to predicting suitbility of tree species in large areas and the space distribution expectation data of 33 climatic elements, and constituted a imformation network. In this method the mixed model with localizing founctions was established by means of large-scale topographic map, in which the surveying information was regarded as independant variable corresponding to dependant variable——the information of tree increment and climatic elements collected from indoor or outdoor investigation. The expectation data of the designed position could be abtained by soluting regression equation in which the surveying informations examined from kilometer network of the topographic map in a horizontal distance form the ordinate and abscissa were taken as independant variable, so the space distribution information network covering the whole investigated area could be constitued.

The relations between understory in Chinese fir plantation, forest stand and site are expounded systematically by anatyzing data inves tagated from 53 sample plots. The results show that the understory in Chinese fir plantation has a great indication, which can be used as one of bases for site classification and evaluation of Chinese fir plantions. However, this indication value is limited unless the understories grow and develop to a certain stage, and results from this indication investigation can not be exaggerated.

Omphisa plagialis Wileman is an important insect pest of Catalpa bungei C.A.Meyer and causes severe damage to the growth of the young trees.The bionomics and control methods were studied in the laboratory and in the field from 1986—1990.It has two generations per year in Henan and overwinters as full grown larva in the branches and in the trunks.The peak period of eclosion of the second generation adult and hatching of the first generation larva (May) are the best period for chemical control.In this period, the control efficacy reaches 100% with 20% Fenvalerate(1:10000) or with 2.5% Decamethrin EC (1:5000); the plastochrone is 5—10 days (spray 3 and 4 times, respectively). Embedding 3% Carbofuran granules around the roots to control the larvae of 1—2 year young trees, the dosage is 25g per tree, the control effect is 97.87—98.10%.

This paper deals with the relationship between meteorological factors and larch leaf cast (Mycos-phaerella larici-leptolepis), and analyse the selected meteorological factors of the different monthes. The results showed that the rainfall and the ralative humidity during June and July and the mean air temperature in April and May were worked out as the disease forecasting factors. The current year forecasting formula of y = b₀ + b₁x₁ + b₂x₂ +……b₍₁₂₎x₍₁₂₎(x₁: values of forecasting factor before 1—12 years, b₁: regression coefficient) was established. Based on the accumulated data of disease and weather condition of 23 years, the disease forecasting formula of y = 68.31-1.68x₁-0.5638x₂ + 0.36x₃(x₁: the mean air temperature, x₂: the ralative humidity, x₃: rainfall) was made. The spread area of the disease can be calculated with the equition of y=(-0.13325 + 0.00533x)Sy (x: forecasting disease index, Sy: area of larch plantation in Jilin Province). The disease level and disease area can be determined with the ratio coefficient of a given disease level. Thus the area needed to be controlled was the combination of serious and medial disease areas plus 20 percent of light disease area.

Three species of the ant genus Acropyga (Hymenoptera: Formicidae) are found in China. Among them one is new to science. A key to the Chinese species of Acropyga is presented. The type specimens are kept in Insect Collection, The Forest Research Institute,The Chinese Academy of Forestry.Acropyga (Atopodon) jiangxiensis n.sp. (figs. 1—4)Worker (Holotype cited first): total length (TL) 2.0, 2.0—2.1; head length (HL) 0.58, 0.57—0.61; head width (HW) 0.47, 0.46—0.49; scape length (SL) 0.37, 0.37—0.42; head index (HI) 81, 79—83; scape index (SI) 79, 76—91; Weber's length of alitrunk (WL) 0.51, 0.49—0.54. (Unit: mm, Five individuals were measured)Head slightly longer than wide, with slightly convex sides and shallowly concave occipital border. Mandibles subtriangular with 5 teeth. The apical 3 teeth smaller and poited, the 4th larger than the 3rd, slightly smaller than the apical 2; basal tooth heavy and truncate. Eyes smalle, 0.03mm in maximum diameter. Antennae 11-segmented; 10th as long as broad} last segment 2.1—2.9 × as long as broad. Clypeus convex, without median crina; its anterior border slightly convex. Frontal area distinct, subtrian-gular. Maxillary palpi 2-segmented; labial palpi 3-segmented.Lateral view of the alitrunk convex, propodeum very sloping; pro-mesonotal and mesonotal-propodeal surture distinct. viewed from the above, pronotum 1.5—2.0 × as broad as long, petiole with the general shape.Head, alitrunk and gaster shagreened. Mandibles shining, with some shallow punctures. Clypeus with sparsely punctures. Anterior part of head with several long haires. Anterior border of clypeus with no more than 3 long hairs. Suberect hairs abscent on other part of the head and antennae. Alitrunk with several pairs of erect hairs. Apex of petiole node without erect hairs or with 1 to 2 hairs. The whole body covered with dense pubescence.Color white to pale yellow; with the tibiae, antennae and mandibles reddish; mandible teeth reddish brown.Male: TL 2.4: HL 0.37—0.41; HW 0.25—0.33; SL 0.28—0.29; HL 68 —80; SI 89—110; WL 0.75—0.76. (Two individuals were measured)Head longer than wide. Eyes large and very convex, 0.16—0.18 mm in maximun diameter. Mandibles 4 teeth, the apical 3 sharp poited, basal tooth large, more round, not rectangular. Antennae 12-segmented, the 2nd 2.3—2.7 × as long as broad, 3th-llth longer than wide, or approximatedy as long as broad. Ratio of length from 10th segment to last one, 4:5:14. Maxillary palpi 2-segmented, slender. Labial palpi 3-segmented.Dorsal outline of alitrunk round, petiole node thin. Wing veins as in figures.Body subopaque with sparse punctures, covered with dense pubescence. Mandibles with several long hairs. Gaster with sparse hairs.Color pale yellow, slightly brownish, Area near ocelli blackish brown. Terminal antennae segment a little darker than the others. Mandible teeth reddish brown.Holotype: worker, 11. Ⅸ. 1989, Dagang Mt., Fenyi County, Jiangxi Provin., Wang Changlu leg..Paratypes: 14 workers, 2 males, same as the holotype.This species resembles closely with A. baodaoensis Terayama, but differs from the latter in the following characters of worker: l.Head and antennae without numerous suberect hairs, anterior border of clypeus with no more than 3 long hairs, apex of petiole with 1—2 hairs or without hairs. 2. Clypeus without median crina. 3. Vertex without large dark subtriangular spot. 4. 4th tooth not distinctly larger than the apical 2. Male of the new species differing in the following characters: 1. Second segment of antennae 2.3—2.7 × as long as broad (3.0× as long as broad in baodaoensis). 2. Terminal mandible tooth triangularshaped.

In order to balance production in log yard, we need tree-length storages. The key is where tree-length storages are, at log yard, langing or both. The problem is still in arguing. The article regards the forest logging system as a study object, and establishs calculating mobels about the cost consumption of tree-length storages in logging, transporting and log yard stages, and also deduces relacionships among them and distributing coefficient of tree-length storages (α) in landing. The article developes a function of total tree-length storage cost and α, However, after calculating practicaily if the total tree-length storages Q is<200 thousands m³, would be a minus value, This means that the total tree-length storages should be in log yard. In general, the total tree-length storages of an enterprise cann't exceed 200 thousands m³. Therefore,the distribution problem of tree-length storayes does not need to be considered at present.

This paper dealt with the longitudinal air permeability of 40 important Chinese woods. Their perweable characteristics and laws were revealed. The air permeabilities measured at about 10% M. C for softwoods were between 0. 00957 and 1. 87173 darcy,while for hardwoods were 0. 00195 to 13. 49867 darcy. The permeability of sapwood of both softwoods and hardwoods was much higher than that of heartwood. The permeability of wood was not related to its density in regardless of softwood or hardwoodand the same or different species. In the 40 species studied, the permeability of heartwood of all softwoods, about 70% ring-porous and about 30% diffuse porous or hemidiffuse porous woods was below 0.1 darcy, which belonged to a low range of permeability. The species of low permeability in softwoods were more than that in hardwoods because the numbers of cell cross per unit length in axial direction which hinder flow of fluid in the former were more than that in the latter. The species of low permeability in ring-porous woods were more than that in diffuse porous or hemidiffuse porous woods as a result of the existance of tylosis or gum which obstructed vessels and pit membrane openings between vessels. As far as softwood was concerned, the difference of permeability relied on the effective radius and number of pit membrane openings, as for ring-porous woods was also dependent on the existance and number of tylosis or gum in the vessels, even the number and size of openings in the tylosis in addition to the pit membrane openings between vessels, and as for diffuse or hemidiffuse porous woods resulted from the radius and number of pit membrane openings between vessels, the type of perforation plate contained in the vessels and the radius and number of vessels.

The main mechanical properties of Ph. pubescens and Ph. Bambusoides with and without nodal were investigated. The results showed that static bending strength, compression strength parallel to grain, shear scrength parallel to grain, tensile strength parallel to grain and toughness in impact bending of the bamboo wood with nodal tend to reduce in a degree. Howerer cleavage strength and tensile strength perpendicular to grain increased obviously. The main factors affecting the mechanical properties of bamboo wood included the quanty of vascular bundle, the orientation of vascular hundles and the fiber strength in vascular bundles. The regularity as indicated above was important for the structure bionic of the composite materials.

Young stems, leaves and callus of Gypsphila paniculata were inoculated separately with Agrobacterium rhizogenes strain LBA 9402. After 18 days from inoculation hairy roots were induced on the sites inoculated, which had not geotropism, grew luxurianlly and produceed branches on MS medium without any hormone. Calli were induced by exposing hairy root fragmants to MS medium supplemented with 2, 4-D 2mg/L and BAP 0. 5mg/L, which were subcultured for 7-8 weeks on MS medium containing 2,4-D 0.2mg/L, zeatin 2mg/L, and then transfered to hormone free MS medium for a regenerated plant. Agropine and mannopine were found out in the hairy roots, calli derived from hairy roots and the regenerated plants by means of electrophoresis examination, indicating that Ri T-DNA of Agrobacterium rhizogenes was conformed into nuclear gene group of G, paniculata.

Rhzobia enteres the nodule cells of leucaena roots with the aid of infection thread which contains rhizobia in embedding matrix when the infection thread penetrated the nodule cells. This matrix surrounded by the infection thread wall of host plant is probably a product secreted by bacteria. While the infection thread wall is surrounded by plasmalemma whichn connected with infection cells. During the process of nodule development, bacteria released from the top or side of infection thread enteres the cytoplasm of infection cells again. Morphological and structural changes hapen in both infected cells and non-infected cells. The characteristics of the change in cell structure related to nitrogen-fixing function are pointed out.

The results of investigation showed that: there existed obviously a "slow-fast-slow" growth rhythm in height growth process of one-year-old Cinnamomum platyphyllum seedlings. This growth process could be simulated with Logistic curve. The different growth stages could be divided with derivating the Logistic equation. There was a positive correlation between rate of height growth and rate of leaf area increament. The nitrogen (N) content in leaf of the seedlings was the first important for height growth, phosphorus (P)content was the second, and then was potassium(K). The growth rate of height was closly related to air temperature. Proper shading, irragating in time as well as solving the contradictions between the supply and demand for water, fertilizer and temperature at the fast growth stage were the key techniques for growing good saplings.

To make level terraces for planting trees in mountainous areas in northern China, an explosive technique was developed for intansive site preparation. It was found that the phisical and chemical properties of soil could be very much improved through explosion and the sheet erosion was also obviously reduced. Another effect of explosion on site was that more suitable environment was created for the development of tree root systems. This technique was particularly effective measure for establishing economic forest plantations on rocky sites. It was also found, however,that the effects varied with explosion depth and explosive amount.

Density trial of populus' Zhaolin 6' in intensive culture plantation was conducted in Jianping County, in the semi-arid area of West Liaoning Province from 1984 to 1989. The results showed, (1) There were great differences in forest tree growth, stand structure and economic benefit among the 3 planting densities treated in this trial. (2) The numbers of forest trees showed a normal distribution by allocation of diameter classes. (3) The shape of tree stem and its ampitude were also affected by density. (4) Diameter class and yield of forest trees were determined by forest tree density, therefore which had great influence on price of trees and economic benefit of plantation; the average annual production value of 6-year-old stands with density of 4m×4m, 4m×6m and 5m×6m was 3300.27yuan/hm², 3361.00 yuan/hm² and 3009.50yuan/hm² respectively; under local conditions plantations of 4m×4m and 4m×6m were suitable for developing middle-diameter timber, cutting at 10-12-year-old, and plantation of 5m × 6m was suitable for developing large-diameter timber, cutting at 12-15-year-old, from which the satisfactory timber yield and the great economic benefit could be achieved.

Eupterote sapivora Yang is a new forest insect pest injuring 22 tree species belonging to 15 families. It mainly attacks Panlownia tomentosa, Toona sinensis, and Sapium sebiferum. There is one generation a year in Guizhou Province. It overwinters in the pupal scage. There 7 instars in the larval stage 1-3 instar larvae feed on leaves on the upper part of the tree, while 4-7 instar ones are distributed on the middle and lower part of the trees. At daytime, the larvae remain still gregariously and form a ball. While at night, they feed on the leaves. The larvae appears in the middle of June. The peak period of infestation is from August to September. The larvae pupate in middle October. The outbreak of the pest is related with temperature, humtdity, altitude, slope, slope inclination, tree species and age of the tree.

M=a₁H_t^b₁c₁ and M=a₂D^b₂N^c₂. are regarded as the binary mathematical models for the equiheight line and equidiameter line respectively, and M = a₃D^b₂H^c₂N^d₂ as the cubic mathematical model for the complex equiheight-equidiameter line, which can fully reflect the relation among stand density and amount of volume and its changing rule precisely. It is proved that the bases and method for drawing up the models are significant widely.