In order to research the influnce of provenances of Cunninghamia lanceolata on koryotype, seeds are collected from 20 different provenances, they are kept on the damp filters under the condition of 25℃ for germinating till their roots grow to 0.5cm in length. After being treated with 0.02M 8-hydxoxy quinoline for 4 hrs, they should be taken the slide preparation.Every chromosome complement consists of 22 chromosomes, and 1 or 2 B-chromosomes have been found among 5 provenances. The karyotype is one that has the nature of polymorphism which is characterized by its satellite shape and location and its heterozygous nature relevant to the shape and the location mentioned above. The satellites can be classigied into big-satellite, smallsatellite, compplex-satellite, linesatellite and T-satellite. The satellites usually settle down in a certain pair of chromosomes, they change their locations from one pair to another among the 1st to 5th pair as well. More often than not, the satellites are located on the short arms of the chromosomes, but a few of them have also been observed on the long arms of the chromosomes at times.Through miltivariate analysis, it is verified that the karyotype from Dechang provenances in Sichuan province is more individually geographical and ecological type than that of those which are from any other provenances. Gene drifting of that isn't obvious. Though the type is widely distributed among 19 provenances, its type are the same. It isn't influnce for latitude and longitude on variety, of satellite.

In order to breed a fast-growing species with high tolerance to less favorable environment in northwest and northen regions of China In 1957, Populus simonii as female parent was crossed with mixed pollens (in 1:8) of P. pyramidalis and Salix matsudana used as male parents. Created by this combination were hybrid seedlings, from which 10 best young trees were selected to form a new cultivar named 'POPULARIS' which including 10 individual clones (CV. 35-CV. 44).The tests for identifying the characteristics of 'Popularis' shows that 'Popularis' possess the following advantages: fastgrowing, high efficiency of photosynthesis, tolerance to salinealkali soil, drought-resisting, resistance to Cytospora and Dothiorella diseases as well as fine timber quality.Its isoenzyme analysis and immunochemistry test also show that Salix plays a part in crossing produre.Regional tests have proved that 'Popularis' is suitable to grow in the Northwest, North and Northeast China.

The materials studied in many years have shown that there was a worse change of ecological conditions on the cutting areas in the west subalpine belt of Sichuan province. For example, there is great difference in temperatures and the soil moisture percentage decreases. The water-holding power is weaker than before.Some shrubs and weeds invaded, etc. If no better management given to that area the condition will be worse and worse. So that we shall cut reasonably and regenerate on time in woodland. Then, the forest will be reestablished on most cutting areas and a new ecological balance will be taking place.

The site type of a stand is the material basis for the growth of forest crop. In forestry practice establishing the site type of a stand exclusively by professional knowledge and practical experience may sometimes fall into fallacy, resulting in inadequate forest operations, hence economic loss.Based on the theory of Bayes and using factors closely related to site types of stands, the author developed a functional formula for site type identification. In practice, through tentative determination of the site type of a stand by experience supported by calculation with the identification formula, it is possible to secure a very precise assessment of the site type, thus providing a theoretical basis for adopting desirable silvicultural measures.

The blister rust of Mongolian pine is an important disease. The pathogenic fungus is identified as Cronartium flaccidum (Alb. Et Schw.) Winter, its telia host under natural conditions in Heilongjiang Province is Paeonia species. The fungus also infects Melaplexis japonica under inoculation. The spreading period in woods for its aeciospore is 56 days and the spore can be caught at the distance of 30m, the vertical is about 5m high with abundant collection of spores. Aeciospore is binucleate, only one germ tube has priority to grow. On the 2% agar water membrane with temperature 20℃ under saturated moisture, and pH about 7 the germination rate reached 80%. The germination rate of uredium can be raised about 15% if exposuring in the sunshine before germination. The germinating rate of urediospore, on 2% agar water membrane under 25℃, reach 78.4% for 48 hours. The overwintered urediospore on diseased leaves of Paeonia species still can germinate (2.96%) and infect. The teliospore will mature in three days after its formation and then germinate under the temperature 16—21℃ and 3 hours wet condition, producing basidiospores. Hyphae beneath the canker bark of Mongolian pine are perennial, septate, monocaryotic, and grow between host cells, entering cells to form haustoria. Some weed killers may eradicate Paeonia leaves. Using 10%, 20% NaCl solution or 5—10 grams, 10—20 grams of NaCl crystal to spread around the roots can kill Paeonia roots. Smearing chemical medicine on the surface of diseased stems, such as N-dodecyl-12.6-dimethyl morpholine (1000 times), the solution of creosote and machine oil mixed with corn germ oil (1:3 or 1:5), will kill aeciospore although there are chemical harm for twigs and young branches. Pruning including cutting off diseased shoots is an ideal measure to promote the growth of forest trees and the disease prevention.

Tungoil trees dieback is a serious twig disease of Aleurititis fordii Hemsl. in Siehuan. It caused a large quantity of dead twigs. According to its morphology, cuhural, and artificial inoculation, the pathogen has been identified a new species of Nectria aleuritidia sp. Nov.Perithecia are gregarious in groups of 13—19 and usually develop on bursted lenticel. They are globose, or ellipsoid with a pointed ostiolar when mature, red, later become reddishbrown in colour, with a smooth wall and measure 223.1×197.0μm in diameter.The section, the lateral wall of perithecium is 44—53μm wide and formed of two indistinct regions. The outer is 33—38μm, has thickwalled cells, globose and variation in the shape, 4—9×3—4μm. The inner is formed of 4—5 layers of thinwalled elongate cells, 9—13×2—3μm.The asci are clavate, without an apical collar, and with 8 obliquely monostichous to apically distichous ascospores, they measure 58.1×12.7μm (50.6—91.4×12.7—16.6μm).The ascospores are hyaline, ellipsoid, with non constriction or a slight constriction at the central septum. When the spores are mature, they measure 15.7×7.1μm (11.1—23.0×5.5—9.02μm.)

The Larch casebearer in China has hitherto appeared in literature as Coleophora laricella (Hübner). In recent years (1978 to 1982), author collected many specimens of it and studied. The result is that: the Lerch casebearer in China is not Coleophora laricella (Hübner), but C. dahurica Flkv., C. sibiricella Flkv. and C. sinensis Yang. The former is distributed in Heilongjiang, Jilin, Lioning and Hopei province as well as Inner Mongolia Autonomous Region of China; their hostplants are Larix gmelini (Rupr.), L. olgensis Herry, L. leptolepis Gordon. and L. principis-rupprechtii Mayr. And the latter was only found in Sinkiang Uighur Autonomous Region; their host plants are L. sibirica Ledeb.According to the structural character of genitalia for C. dahuria and C. longisignella as well as their host plants, geographical distribution, life history and habits, author hold the understanding that, they may be the same rather than the different kinds.

The poplar-trunk clearwing (Sphecia siningensis Hsu) is a new important insect pest of poplar trees in Qinghai province.It took 2 years to complete its life cycle which may extend over 3 years, in Sining, The adults show emergence period characterized by main group and non-staple group, which reach maxima in August and June respectivelly. The early boring stage of the larval occurred in mid and late July and late September to mid October mainly. The larval stage was seen to consist of 8 instars. The larvae can grow 1 to 4 (or 5) instars in the first year, and 6 to 8 instars in the seconed year. The larvae bore into the xylem alburnums in L-shaped burrows, and all will cocoon, pupate, emergence in its burrows in the third year. Therefore, a lot of the adults and the larvae of the pest population are always presented in each year, due to the succession between different year-group.The females lay the most eggs at the place within 1 m of D. B. H. and at the base of crown near the point of branches. 1. In the early boring stages to spray the tree trunks with 50% Phosphamidon in concentrations 1:50 to 1:100 was good to kill the new larvae. 2. To inject into the burrows on the trunks 40% Rogor or 80% Dichlorvos crude emulsion was effective to kill the older larvae.

This paper deals with the correlation analysis in the light of the principle of mathematical statistics for the economic index of logging railway and truck transportation of logs in Heilongjian Forest Region. The experienced formula for unit costs which varied with annual hauling volume and average haul distance is constructed.The logging railway and truck transportation have their own appropreate ranges as far as the unitcosts are concerned. Accordingly, they should be considered separately in view of economic advantages in the future development of log transportation system. For the best economic advantages it is necessary to evaluate the feasibility of changing the logging railway into truck system as well as their joint transportation.

Calculating output value of silvieulture must follow the general principles of output value calculation and reflects the particularities of silviculture production. In this paper, two concepts calculated price of output value and coefficient of increment are put forward, with which the problem of calculating output value of silviculture is solved in theory. According to the simple and convenient principle in practical application, the concept of coefficient for output value calculation and its principle for application is suggested and the caleulating formula is simplified.

In view of the main problems existing in statistics of the output value of silviculture, this paper suggests a method for calculating value of standing timber which is the main product of silviculture. The gross output value of silviculture should be the total value of all standing timber products, and it can be derived by multiplying standing timber production in the reporting period by relevant stumpage value. The net output value of silviculture reflects the results of living labour in silvicultural activities, and it can be calculated by detucting the value of depleted materials from the gross output value. The output value of silvicultural commodities is reflected in the value of standing timber products, which can be used for commodity circulation in the reporting period.

Results from the experiment show that the inhibiting substance contained in the seed affect the germination of the seeds of Taxodium assendens. This inhibiting substance can be removed by soaking under the fluctuating temperature of 20—30℃ the seeds germinate rapidly, and the absolute germinating percentage can reach above 90%. When temperature is below 30℃, red light can accelerate germination of Taaodium assendens, green light inhibits the process, while in darkness, the germinating rate is quite low. After the soaking, the seeds are mixed with sand, and then, wrap up with plastic filme and place in the sun and the germination hastening can be achieved with the natural temperature change. After sowing by these seeds, the seedling output can be raised.

The roots vigor of young artificial seedling stands of Phyllostachys pubescens strengthens gradually with years. The three years old roots is the most vigorous, the vigor of four years old roots weakens sharply. The yearly growth period of the roots is from late March to the middle of November. Their growth is the best from June to September. The roots growth is assoiated with the sugar and protein content in them.

Through the eight years' study from 1975 to 1983, it is confirmed that the man-made mixed forest plantation (Locust mixed with Poplar) has the following characteristics in comparison with the pure Poplar plantation under the similar conditions:There are less forest diseases and insect pests; The stock volume per unit area is increased by 40—80%.The mechanism of the increase of production from the mixed forest plantation is closely connected with the soil ecological system, e. g. the utilization ratio of photosynthesis, by trees in the mixed forest plantation is raised, the nutrients in the soil of the mixed plantation are absorbed respectively by the deep and shallow roots of the trees; The Locust in the mixed plantation can also improve the fertility of the soil; The out-break of forest diseases and insect pests can be controlled under the environmental conditions of the mixed forest plantation as well.

In this paper, the population dynamics in the process of the progressing succession of the forest vegetations in the Maxian Mountains Forest Region is studied by mathematical analytical methods. The typical and particular pattern of the progressing succession of the vegetations can be divided into the following four stages: stage of shrub, stage of small leaf broadleaf, stage of mixed forest and stage of coniferous forest. Mathematical models of succession laws are also established in this paper.Finally, we put forward the proposals of artificial regeneration and tending in this forest region.

The present paper reports the bionomics and control of the bostrychid, Calophagus pekinensis, which attacks the wood and the wood products. It is considered that the different periods of cutting wood have the different degrees of infestation apperantly, with relation to the transformation of material in store from the different seasons of trees. The degree of infestation is the lightest in June and July.

The method of detecting defects in wood by non-destructive X-ray transmissive technique is studied in this paper and the experimental results indicate that most of wood defects can be detected reliably. According to the difference of their X-ray absorbing, the defects are divided into two types——thick-adding and thick-losing. The theoretical analysis of the above-mentioned experimental results is made.