Seeds of Pinus bungeana from 4 different provenances were studied. Results showed that seed size, 1000-seed-weight as well as the compositions of fat acid and amino acid of seeds varied according to provenances. Seeds from Lin-feng and Ling-chuan appeared to be more dormant and more resistant to osmotic water stress. Under the temperatures of 25/20 and 25/15(day/night), however, seeds of all the 4 provenances germinated quite well, dictating no significant combination effect of provenance and temperature.

This paper is based on the studies of 14-year-old Masson pine plantations of four density group at Mount. Loufong in Guangxi autonomous region during 1978—1981. It dealed with the change laws of nutrient contents of the pine organ and the accumulation, distribution and biologic cycles of nutrient elements of various density Masson pine stand of pole stage. The results indicated that Ⅱ density group (3210 stems/ha) stand had the greatest biomass and accumulation of nutrients and the highest rate of nutrient using. As a reference the studies is significant for regulating and controlling stem-density of pole stage of Masson pine stand, tending and thinning and applying fertilizer and maintaining ecologic balance and high productivity of forest site.

Root-rot is a destructive disease in the tung-oil tree (Aleurites fordii Hemsl.) of Sichuan. The causal fungus identified as Fusarium solani (Mart.) Sacc. was isolated from diseased tung-oil tree roots.Studies on morphology and cultural characteristics indicate that there are many differences between this root-rot fungus and other 8 forma speciales of F. solani from different hosts in China in the size of macrospores and the rate of growth.Test on pathogenisity confirmed that the pathogen is pathogenic to host plant and inoculation experiments of 7 species plants were negative. Artificial inoculation with 8 forma speciales of F. solani to tung-oil tree are unsuccessful.The changes in esterase isozyme of this pathogen and other tested strains was studied with polyacrylamide gel electrophoresis technique. It has been shown that esterase isozyme band, the number and relative rate of migration of the pathogen and all 8 strains could be discriminated.Hence the pathogen of root-rot of tung-oil tree is idefied to be a new forma speciales of F. solani, and is diagnosed as Fusarium solani (Mart.) Sacc. Sp. F. aleuritidis Chen et Xiao f. sp. Nov.

The tendency of development of forest growth and yield research as well as the superiority of compatible growth and yield models were discussed. Chinese white poplar (Populus tementosa Carr.) is an important fast growing tree species in China. The applicability of compatible growth and yield models for loblolly pine developed by Clutter to Chinese white poplar plantations was examined. Clutter's models were fitted to data obtained from 129 temporary plots (60 of them obtained from poplar wood lots, other 69 from shelter-belts) in Hebei and Shandong Provinces, as well as Tianjin City. In fitting poplar data, Clutter's basal area growth model has been modified, because of age structure and growth characteristics of poplar stands. The result of examination demonstrated that Clutter's compatible growth and yield models were basically applicable to Chinese white poplar. These models were also fitted to merchantable volume data. As a result of the present study, equations were developed, on the basis of Clutter's models, for total stand volume yield and growth, basal area growth, merchantable volume yield and growth prediction of Chinese white poplar wood lots and shelter-belts. In the meantime, site index curves for this species have also been prepared.

The mathematics models and their theory inferences are founded for the optimum design of the skyline on forestry cableway in this paper. The BASIC program designed can be used for the optimum design of the skyline of single span or multispan cableways. The program passed in Chinese or English on PC-1500 or APPLE-Ⅱ.The software is efficient, accurate, versatile, easy to operate and fast to calculate.

This paper has reported a new method of reaction between urea and formaldehyde under low temperature and low pH value. Investigations show the different reaction mechanism between urea and formaldehyde. The process of reaction involves a relatively short cycle time. The chemical structure and skeleton of the resin are basically changed. It contains much more methylene functionality than methylene other functionality in the cured resin. The resin exhibits hydrolytic stability and the formaldehyde emission is greatly reduced. Authors suggest that the reaction resultant of urea and formaldehyde under low temperature and low pH value can be considered as a prepolymer (basic resin) to solve the difficult issues, in which the storage life of urea resin adhesive is not long and gelling systems are usually obtained since the ambient temperature variation in storage and shipping.

Most structural timber species now used in the North China's rural areas are poplar, willow, elm etc, which are fast growing trees but whose woods are very susceptible to biological deterioration. It is, therefore, very important to conduct some simple and effective treatments in those region including both laboratory tests and field studies. Some water-borne and oil-borne preservatives have been were selected for these purposes. Field tests were performed at Daxing County, southern suburb of Beijing.Eighteen different preservatives were prepared and their effectiveness to the preservation of Populus tomentosa Carr were based on their toxicities against wood decaying fungi and termites. As well, through two years observations in the rural areas, no cases of decay and insect-bite were found on these structural wood members which had been previously treated with those selected preservatives. On the other hand, several insect-bite evidences cases were found on some individual untreated purlins.

In this paper, a comparison analysis was made based on the investigative data of 70 plots on the relationship between the site factors and the biomass of the organs in Cunninghamia lanceolata plantation of Xijiang river district, an estimative model was related to the biomass and the site factors was established; and the scope values of the fitter site conditions to cultivate plantation of Cunninghamia lanceolata for this district and the biomass of stemwood depending upon the relation with the biomass of the branches and roots were given. A theoretical basis for to select and make a plan for Cunninghamia lanceolata planting-site, and its management was provided for Xijiang river district.

According to the equation of one-dimational flow through unsaturated homogenous soil and the consideration of plant transpiration and soil surface evaporation, a mathematical model has been developed using the ALPHA computer to simulate the soil water movement in the population of Populus beijingensis seedlings. Results indicate that the predictive data are nearly in accordance with the determinative, their relative errors generally under 5%, the maximum of them under 8% too.

This paper describes the sixteen treatments that have been adopted to stimulate the germination of Larix principis-rupprechtii seeds. Three treatments with better promoting effects on the seeds were finally selected:1. Prechilling in snow followed by dehydration and hydration treatments twice;2. 0.1%CaCl₂-12hours;3. 0.5%KNO₃-12 hours.In the three treatment, the effect of prechilling in snow followed by dehydration and hydration treatment twice was the best.In the process of this study, eight indices such as germination percent (GP) germination energy (GE), absolute germination percent (AGP), mean germination speed (MGS), fresh weight of young plant (FWYP), Ⅰ—Ⅲ plant percent (Ⅰ—Ⅲp%), germination value (GV) and germination index (GV) of each treatment were calculated separately. Finally, GI was adopted to comprehensively evaluate the promoting sole of the sixteen treatments in seed germination.

A mathematical model is developed in the paper based on measurement of litterfall in the forests. This model can describe the litterfall process including its amount and rate in a year. Its parameters are easy to be calculated and its accuracy is very satisfactory. It is somewhat similar to the logistic equation in form.

There is a close relationship between the amount of content of P and K in soil and the incidence of the disease. When the content of P in soil is high, the incidence of the disease would be slight. When the content of K in soil is high the incidence of the disease would be serious. Index of invasion is in a negative correlation with P/K based upon the results, ³²P and ⁸⁶Rb were used as radioisotope tracer in uptake by diseased twigs and leaves of Paulownia. Results indicated that the species which is resistant to the disease absorbed more K and less P than the species which is susceptible.

The paper deals with the life history, the life habits and its happen relations with the tree seed, terrain, climate and spreading leaves of Rhynchaenus empopulifolis Chen. At last, the controling measures are suggested in this paper.

This paper deals with Lithosiidae, one of the families of insect fauna at Jianfengling forest area in Hainan Island. Insect capture with moth-killing lamp in the four types of forest vegetation has been done 231 times in 1981-1983 and 44 species 20 genera of this family have been collected. Among them, 20 species have been found for the new records in Guangdong Province. The capturing quantities show that the populations of the insects of Lithosiidae are very small. There are many groups with small population and a few with large population. It is concluded from the species and quanutities of every forest vegetation type that most of the insect species of Lithosiidae are in the tropical mountain rain forest. This can be explained by the fact that there are many host plants such as moss and lichen in this habitat. The appearance poriods of the adults in the fourth quarter and least in the first quarter. Some 82.35% of the insects with previous record in distribution are distributed in Oriental Region.

Napocheima robiniae is a serious pest of the black locust in Shanxi, Shanxi, Shandong, Henan, Hebei Provinces of China. The area of serious damage was only about 10000 mu in Shanxi early in the sixties, but it is more than 100000 mu in the eigties. It was controlled with poison pencil that poisoned female moths over 80%. The number of larvae decreased 98% when bound band of plastic film on the trunk, and wiped out the eggs on it. The mortality of the first instar larvae reached 98.4-99.9% when sprayed dimilin to the eggs cluster, spraying the water suspension of Bacillus thuringiensis and Beauveria bassiana to the 3—4 instar and fullgrown larvae a 60.0—81.3% and 49.0—55.6% mortality was obtained respectively. The increment of timber reached 0.178—0.225m³ per mu for the control.

According to the special features of wood X-ray picture, the authors use a new method—Double Filtering Pseudo Colour Processing, to enhance the wood defect pictures. There are two main parts in this paper; processing and pseudo colour processing. The first part includes mid—filtering, low—pass filtering and edge smoothing; the second part is mapping different gray—level of white—black pictures to corresponding colour of pseudo colour images. Two typical defect pictures, thick—adding and thick—losing, are processed in the article and the experimental results indicate that the new processing method is quite effective in both cases.