The differences in forest structure display significant functions. In two different structured Korean pine stands, the global radiation, reflection, penetrance, biomass, productivity and leaf areas have been analyzed in the eastern mountains of the Northeastern China (N15°23′—26′, E127°36′—39′). It is identified that the productivity and biomass of "doublelayered forest" is higher than that of "singlelayerd forest", even though they grow in the same site, expose to the same enviroment, and receice the same rediation input. The main reason for this is that the doublelayered forest can effectively absorb and ultilize the light energy, highly accumulate organic matter in the stand and vertically distribute relatively large amount of leaf area. Those can attribute to the ratioal structure of doublelayered Korean pine Forest.

The observed data of poplar Beijing plantation in 1986 and 1988 were processed, a quantity of parameters and functions and the logical network (the physio-ecological model) were determined from the Soil-Plant-Atmosphere continous system (SPAC system). Based on this models, the short term (10 day) variation of the physio-ecological index of the water absorption, storage, water potential, transpiration of the Beijing poplar in SPAC system were predicted hourly and daily by microcomputer. The relative errors were below 8% and the maximum individual error were not exeeding 15%.

Various compositional elements of the tissue where laticiferous canal lies in T. verniciflum contain osmiophilic droplets. According to the lipophilic property of lacquer, these osmiophilic substances may be lacquer or its precursors. Electron microscope photographs suggest that lacquer is synthesized in ER cirsternae in T. verniciflum, and that they may be eliminated from protoplast to the space between the plasmalemma and the wall in two ways: (1) by the vesicles from ER and Golgi body approaching the plasmalemma and fusing their membranes with the latter; (2) by their becoming surrounded by plasmalemma invaginations, and then they are transited to secretory cells of the laticiferous canals by the channels of plasmodesmata and percolation through the wall.

In six kinds of densities. above-ground biomass of six-year-old poplar plantation (Ⅰ-72/58)was compared on intensively cultured plots in Shan dong province. The average-sampling-tree method was used to estimate the biomass and the net production of the poplar plantation of different age The biomass yields of six-year-old poplar plantation ranged from 64 to 122 t/ha in six kinds of densities; The higher the density, the more biomss of plantation was. The greatest net production was 20 t/ha. yr. in higher planting density (1000 trees/ha) and some others were over 10 t/ha. The proportions of biomass composition. (stems, barks, branches and leaves) were respectively as follows: 60—70%: 10—12%: 12—21%: 3—5%. The yield of biomass was increasing rapidly after second year in each density plantation and it still kept the increasing tendency when they were investigated. Allometric method was used too. The results of above mentioned two methods were compared. The comparision showed that both ways to estimate the biomass of poplar (Ⅰ-72) plantation were suitable.

Beijinga utila Yang is an ectoparasite and monoparasitism insect. It is an important natural enemy against Eulecanium gigantea (Shiji) and Eulecanium kuwanai (Kanda 1934). It has one generation each year. The pupa cocoons overwinters under the scales of female host adults. Its imagos emerge till the first or the second ten-day of May, which are corresponding with imago stage of the female host insects. So the scale insects can be effectively suppressed. The average parasitiztion is 32.7% (from 22.5% to 44.2%) on Eulecanium gigatea (Sliji) during 4 years, and 15.1% (from 7.4% to 21.5%) on Eulecanium kuwanai (Kanda 1934) during 3 years. It choices the host. Parthenogenesis is not occurred in this species, and the larvae usually kills each other.The larvae of Beijinga utila Yang is obviously not affected by the poisons when chmicals is used to control the new-hatched nymphae, the last 1st-instar and early 2nd-instar nymphae of the scale insects. Temperature has a greater effects than relative humidity on ernergnce, coition and ortposition. But its incubation dos not demand the strict temperature and relative humidity.

The white wax insects are insects of resources produced specially in China. They are distributed over vavious areas in China. Our experiments have shown that the white wax insects bred in different areas have notable differences in the output and quality of white wax insects. The white wax insects which can bring much oviposition amount, high male egg's ratio, long wax producing time, much wax producing capacity and high output of wax insects are bred in the lower reaches of the Jinshajiang River, a contiguous area to Yunnan, Sichuan and Guizhou provinces. Therefor, they are fine varieties of white wax insect in China.

The overall design of a forestry bureau is a complex socio-economic system engineering. It plays a very important part in the decision procedure of the development and research of a forest region. The paper, in the practical need of the overall design of a forestry bureau, makes a systematic research and inquiry into a forestry bureauts system objective, function) and structure optimization and the effect assessment of its system development design as well.

The overlaying process of particleboard involves a compressive rheological behaviour to the particleboard itself. In order to get a better understanding of the process and controling the thickness tolerance of overlaid particleboard, a rheological analysis can be adopted to the study of the behaviours of particleboard under compression perpendicular to its surface.Four kinds of creep-recovery curves can be identified in the wide range of compressive stresses as the creep behaves differently at different stress levels. The statistical results reveal that: the standard error of instantaneous elastic deformation is smaller and relatively constant; that of instantaneous plastic deformation is relatively larger and increasing as the stress inereases; the standard error of time-dependant plastic deformation increases with stress, and similar to that of the retarded elastic deformation, which increases as the creep time prolongates; the changing pattern of standard error of thickness decrement is consistant with that of instantaneous and time-dependant plastic deformation.Because the big voids in the most wood particles have been compressed during the manufacture of particleboard, the values of compressive theological parameters of particleboard are smaller than those of the original poplar wood.

A Safety and allowable high-strain formula for band Saw-blades is proposed, according to the endurance limit of alternating stress in unsymmetrical bending (or pulsating) circulation, and comparisons with those formula given in the Japanese Hand-Book of wood Industry(1982)and with high-strain upper limit curve in Kockums Group (sweden) were also observed. The investigation revealed that an allowable maximum fluctuating stress, converted to iso-effective pulsating circulation, acting on the sawblade, is approximately 250N/mm². when the tensile stress increases, it is necessary to use a thinner saw-blade in order to decrease the bending stress to compensate the increased tensile stress rendering the total stress maintaining approximacely unchanged.

This paper presents studied the water—physical and chemical charater and the soil nutrient of forest soil in loess region. The results obtained are summarized as follows:The water—physical charater of follen leaves and humus horizon of forest soil are; volume weight lower, noncapillary porosity development, capillary porosity nondevelopment and content of saturaed water higher, these charater all advantaged admit precipitation, conservative water and soil and avoid flow-off.The chemical charater of forest soil are: lower pH, content of calcium carbonate reduced in follen leaves and humus horizon; organic matter, total nitrogen and total phosphate in accordance with index equation(Y=Ae^B/X) in distrebution of porofile. But total potassium accordance with index equation (Y=Ae^-B/X).The available nitrogen, phosphate and potassium of lower with increase of depth.

The biomass is determined and the mineral content is analyzed for the hardwood-Korean pine forest in the Lesser Xingan Mountains: The total biomass of the forest is 363.9 t/ha, which consists of three compart ments, korean pine 304.5 t/ha, broadleaved trees 47.4 t/ha, and understory vegetation 11.7 t/ha.Most of biomass accumulates in trunks, 191.0 t/ha, which is more than 1/2 of the total biomass. The root biomass is 89.3 t/ha, about one fourth of the total. Rests are accumulated: in leaves, branches and barks.The total amount of nine nutrient elements including Cu, Zn, Mn, Fe, K, Ca, Mg, P, and N, is 3174.1 t/ha, which is 0.87% of the total biomass. The elements with high contents in the biomass are N (1056 kg/ha), Ca (999.3 kg/ha), and K (763.6 kg/ha). The elements with low contents are Cu (2.4 kg/ha) and Zn (7.0 kg/ha). The nutrient content in korean pine accounts for 63.7% of the total nutrient amount, broadleaved trees 27.4%, and understory vegetation 8.9%.

The growth and the accumulation prosess of dry matter of the Chinese Pine's and Chinese Arborvitae's containerized-seedlings under the plastic greenhouse condition which not being controlled are studied in this paper and compared with those (seedling) grown under the field condition. The main results obtained as following:1. The biomass of the containerized-seedling under the condition of the plastic greenhouse are lower than those under the fiold condition, the difference between the two conditions is highly significant.2. The overwintering survival rate of the seedlings in the plastic greenhouse shows also a relatively lower percentage compared with those under the field conditions.3. The difference of the net assimilation rate among the three treatments in both species is extremely significant, the highest net assimilation of Chinese Pine's seedlings appeared in May and June, while that of the Chinese Arborvitae seedlings appeared in July and August.4. The major factor which influences the net assimilation rate is the high temperature.

Rooting mechanism for Populus tomentosa was studied by using ¹⁴C-α-NAA trace technique in this paper. Obsergations on ~(14)C-activities from ¹⁴C-microautoradiograph showed that the acting location of NAA was in cortical parenchyma cells which would produce meristematic cells. The role of NAA in the formation of root primordium is the induction of cortical cells to differentiate meristematic cells which possess meristematic ability. The root primordium distributed mainly in the parts of cuttings treated with NAA, which did not relate to the polarity of cutting icself. 590ppm NAA will be good for producting roots since adventitious root formation can be promoted obviously while its growth can not be inhibited by NAA. On the average, 8 adventitious roots per cutting will be induced from cuttings treated with 500ppm NAA for 40 days at soil tempematures of approximately 20℃, which have an average length of 4.5cm.