The study deals mainly with the principle and practice of juvenile seedling grafting of walnut for four years from 1978 to 1982. The results are summarized as follows:1. The survival percentage of juvenile seedling is 80% or so.2. It gives fine quality seedling.3. The period of raising seedling is one or two years less than that of seedling by the ordinary cleft grafting method.4. The average total cost is 45% lower than that of cleft grafting.

The geographical differentiation of Pinus tabulaeformis Carr. Is discussed and illustrated by means of multivariate analysis with data from 18 morphological traits of needle, cone and seed in 54 natural forest stands. According to the results obtained from cluster analysis and principal component analysis, nine local populations are classified.

The paper is concerned with the seasonal variability in rooting capability of×Populus pekinensis stem cuttings and the effect of buds treated with IBA. The endogenous plant hormones are extracted and sisolated from the buds and bark in the different time of the year, and the relaton between plant hortnone level and rooting capability of×Populus pekinensis cuttings has changes in different seasons. However, the cuttings with buds root always better than those without buds. The effect of IBA on rooting capability is different in cuttings with or without buds. It is also changing in different seasons. It is proved by bioassay and GC measurements that the capability of sprouting and rooting of×Populus pekingensis cuttings is closely related to inhibitoris, among the endogenous ABA appears the most effective component.

Plant height (H), leaf area (a), total leaf areas of individual plant (A), length of branch (L), dry weight of stem (h), net photosynthetic rate (t) and dry matter productivity of each plant (T), etc. were measured in annual cuttings of 20 clones of 10 willow species. Genetic variations and correlations of photosynthetic characteristics were studied by means of variance, correlation and path analysis. Results show that genetic variations of photosynthetic characteristics among species and clones varied considerablly. Direct influence of total leaf areas on plant height is greatest, that is P_(HA)=11.3838. The components of correlative coefficients between plant heigh and photosynthetic characteristics also show significantly positive effect of total leaf areas (A). Therefore the key factor for breeding willows for timber production is to increase total leaf areas of the individual plant.

Erythrophloeum fordii is one kind of protected and rare trees in our country. It has special economic value. The percentage of hard seeds in E. fordii is very high. Under natural condition, the germination of the seed is very difficult.This paper studies the following problems: (a) the structure of the seed coat, (b) the function of the fissure in the hilum, the germination inhibitors and promoters in the seeds.The results show that the structure of the testa which prevents water uptake appears to be a layer of palisade cells. The cells which arrange closely possess thick walls and narrow cavities. Treatment with sulphuric acid may alter the impermeability of the seed to water, because the layer of palisade cells is destroyed.The results also show that the fissure of the hilum operates as a hygroscopically-controlled valve. It opens when the seed is placed in dry air, and closes in moist air.The author measures the total activity of extracts from testa and embryo. The results of paper chromatography and bioassay, show that there arc inhibitors in the testa and embryo. After soaking the seeds, the inhibitors are decreased obviously and the promoters are produced.

This paper deals mainly with the application of computerized successive-regression to the forecast of incidence quantity of Dendrolimus punctatus Walker, with its focus on the analysis of the effect peculiarity shewed by climatic conditions.Historical records and infomation from 29. counties, city or forest farms in ten provinces and one autonomous region are analysed and a series of forecast mathematical models worked out by the computerized successive-regression. The author also divides the incidence of D. punctatus walker into three areas in China.

It has been known that' the mechanical preparation of wood surfaces or exposure of them to the ordinary atmosphere will induce free radical formation due to molecular fractures of wood chemical components. Thus, mechanical or photochemical actions may lead. to the modification of wood surface characteristics both chemically and physically. The present paper is dealing with some results of ESR investigation of free radical formation and decaying behaviors in the processes of wood cutting and photo-irradiations. Attempts are made to the identification of those free radicals and their reactivities with adhesives and the mechanism of photo-chemical reactions of wood are also discussed.

The arabinogalactans from Larix gmekini and L. olgensis are isolated and characterized, correspondingly, the cotents are 7% and 10.2%, the molecular weights (MW) are 53000 and 44000, respectively. Both species are resemble each other in sugar composition which includes galactose, arabinose and uronic residues, and the ratio of galactose to arabinose is approximately 6. The results of SEM and DTA show that the effect of arabinogalactan on hydration and crystallization of Portland cement is seriously harmful. It is an inhibitor of setting and hardening of Portland cement.

In connection with the practical problems of the curvature conveyor in wood production this paper puts forward a plan for improving the supporting structure of the track in the curved parts of the conveyor on the basis of investigations and some analyses and calculations in theory are made on the curvature radius, the main parameter of the curvature conveyor. As the result, a general formula of the curvature radius is obtained.

The transpiration rate has been determined for three tree species by fixed-point through a year in Guangzhou. The results shew that the water transpiration yearly (1395 trees per hectare) is 4817.60 ton/hectare, 9944.06 ton/hectare, and 13631.72 ton/hectare, respectively by Eucalyptus torelliana, Cunninghamia lanceolata and Acaia auriculaeformis.Statistical analysis proved that the variance of transpiration rate is mainly limited by the environmental factors of light intensity and temperature. The practical equation established from multiple regression analysis is a simple method to measure the transpiration rate for those tree species.

The paper studies mainly the following problems:(a) The allometry phenomenon of Pinus yunnanensis. (b)The law of allometry constant "K" in different age of a plant.

Survey has been conducted on the vegetative coverage in some different typical types of environment covered with trees and other plants for testing the environmental factors and the effects on eliminating the physical weariness.The tests show that the good vegetative environments are of great advantages in eliminating the physical weariness and improving the health of the human body. These advantages may be also expressed in numerical index.

In order to improve management level of Pinus massoniana forest, the author designs a management-calculation diagram, which is a improvement on the old stand density diagram. Because of the equivalent height curve and equivalent diameter curve replaced by two parallel graduated lines the new techniques adopted in the preparation of the diagram makes its structure simpler than that of the old stand density diagram. It provides a new way for timber cruise, estimation of growth and afforestation design. Its precision is high enough to meet the user's requirements of productive units.

The predatory stink bug (Arma chinensis Fallou) is commonly found in North China. It attacks many lepidopterous and coleopterous hosts. In the laboratory under various constant temperature conditions the biological constants are computed. The results are shown as follows:

Sparganothis pilleriana is a kind of more-eating injarious insect. It is new discovery to harm L. olyersis. When the tip of a young tree is harmed, it decreases about 65.2% in the high growth of L. olgensis and cause branches off.It has one generation a year. The adult ovipoits on the back of herbal leaves, and larva moves to young L. olgensis, when hatched. They have many natural enemies.With the use of Bacillus thuringiensis (1—2×10⁸/ml) or 800—1000 times 1605 for the larva and of 621 for the adult, more than 80%pests of S. pilleriana in L. olgensis can be killed.

Pinus massoniana is one of the main conifers indigenous to china. The analysis of variance indicates there is a significant difference (a=0.01) among wood pH values of different height within a trunk and among the trees. On an average, its wood pH value is 5.33, and total buffering capacity is 2.33. This report also includes regression analyses for pH variation of wood extract solution with respect to adding nominal 0.0250N sulfuric acid or sodium hydroxide solution.

Dalbergia fusca is a tree species belonging to the Papilionaceae, and an endemic species in the Xishuangbana area of Yunnan province This paper deals with its wood structure, physical and mechanical properties and uses.The heartwood of Dalbergia fusca is dark-brown to black in colour, extremely heavy and hard (air-dry density 1.13 g/cm³, hardness 1232 kg/cm² in the transverse plane), and small in volume shrinkage. Some qualities and uses of the wood are similar to imported rosewood. It is a valuable timber for making musical instruments, high-classed furnitures and carvings, etc. Some experimental results in factories are reported in this paper.