This paper deals with the relationship between soils and mean annual Increment single poplar tree in the vast plain of eastern China. According to the climate, the geomorphy, the parent materials, and the groundwater level, soils of this region may be divided into ten types. The sequence of their fertility is as follows: grey fluvo-aquic soil, red clayed fluvo-aquic soil, loamy fluvo-aquic soil, fluvo-aquic cinnamon soil, desaline fluvo-aquic soil, carbonate cinnamon soil, shajiang black soil, saline fluvo-aquic, sandy fluvoaquic soil and solonchak. Compared with the forest soil in mountainous region, the organic matter content and total nitrogen content in all plain soils are poor. Except soil available potassium, most plain soils are also poor in available nitrogen and especially available phosphate. Both in the soil or in the ground water all over the plain the calcium is very abundant, it suits poplar-calciphile very well. The datum of mean annual increment of 16 poplar clones and 3 other broad-leaved tree species in different soils have been given in this paper. According to the results of the former study, it is proved that each poplar species has its own suitable site.

On the basis of analysing 34 forest ecological factors about climate, soil, landforms and. geology, 42 forest ecological counties are classified with cluster analysis and principal component analysis (PCA) and the reliability of 5 alternative of classification are examined with the method of discriminant analysis. With the aid of said numerical classification, 42 forest ecological counties of Jilin Province has merged into five forest ecological districts.Brief description of each district is given which will provide scientific basis for the conservancy and administration of forest ecological system.

The use of improved ER medium will enable cotyledons basis and cotyledon petiole of the Thea sinensis L. to develop embryoid. The cytohistological and morphological investigations on the changes in developing process of embryoid have been made in detail. Our works reveal that the embryoid of Thea sinensis L. are differentiated from the epidermal cell of cotyledons. The initial separating patterns of the embryogensis in embryo and embryoid are different. But it js more similar in their form-formative processes. We also found that the different kinds exogenous growth regulators and their quantity used for the cultural medium will affect the differentiations of embryoid and the formation of young plants.

The red pine bast scale, Matsucocous koraiensis Young et Hu, is a pest of Korean pine (Pinus koraiensis) widely distributed over the virgin forests in the eastern mountains of the Heilongjiang and Jilin provinces. In Fenlin district the Korean pine bast scale has one generation a year and overwinters in the 1st instar. After overwintering the 2nd inster larval stage is a chiefly injuring period. The adult emerges in early June and become abundant in mid-June. Reproduction is sexual, but we observed that one of the females produced eggs before copulation. On an average, each female oviosits about 96 eggs. The young larva hatches in the later part of June and becomes abundant in mid-July. The Korean pine bast scale insects mainly in the virgin forest of the Korean pine distributed on the southern or south-western slope. Eight blocks of the younger pine plantation were recently investigated, but no bast scale was found. Some scale insects have been inoculated against the plantation, but whether they could overwinter or not must be determined by further observation. Aphislions and ants are the important natural enemies which considerably control the population density of this pest.

In order to find out the law of the growth and decline of D.puntatus Walk. and develop a mathematical forecast model, the writers collected the 17 years' historical material of D. puntatus Walk. And the meteorological factors at Lianjiang County in Fujian Province. Twelve main factors were selected and then graded. The calculation method of probability regression in the theory of quantization was used for developing the mathematical forecast model. With this model for forecasting 100% accuracy can be achieved. The predictions of the degree of harmness of this insect in 1978,1979 and 1980 were successful.

Two species of sawflies new to science are described in the present paper. Type specimens are deposited in the insect collection of the Forest Research Institute, the Chinese Academy of Forestry, Beijing, China. 1. Conaspidia kalopanaeis Xiao et Huang sp. nov. This species resembles Conaspidia guttata (Matsumura), but distinguished from it by mesonotum entiraly yellowishbrown, female mesopleura with fewbig shallow punctures, lancet with 21 annuls, each serrula with regular small teeth. Holotype:, Jiangxi province. Allotype:, the same as for the holotype. Paratype; 4,8, the same as for the holotype. 2. Messa taianensis Xiao et Zhou sp. nov. Nearest to Messa leucostoma (Rohwer), but differs from it in antennal segments 1—2 basally and segments 3—4 dorsally black, the rest yellowish brown, ventral surface of antenna yellowish, head black except for clypeus, labrum being yellowish, lancet with 1st serrula with four posterior subbasal teeth, 2—3 serrulae with five posterior subbasal teeth, 4—11 serrulae with 6—8 posterior subbasal teeth. Holotype:, Liaoning province. Allotype:, the same as for the holotype. Paratype: 5, 4, the same as for the holotype.

Olive anthracnose, Colletotrichum gloeosporioides, was prevalent in the South of Qin-ling in Shanxi. When the disease was serious, it caused 30.4—40.3% decrease in the yield of oil of olive fruits. The pathogen mainly attacks the Olive at asexual stage. The pathogenic fungi are made of 2 types:the mycelial type producing abundant mycelium and few conidia; and the conindial type producing many conidia with seta and very few mycelium. The incubation period is to be 2—7 days. The difference in disease resistance of varieties was notable. It seemed that the structure of the epidermal cells of Olive fruits was relative to the disease resistance. When the disease was prevailing, the control using 800 times 50%Tuzet or 1% Bordeaux mixture resulted in satisfaction.

The process of Wood Plastic Combination (PWC) is discussed in the paper. Timber is injected with polyvinyl element with positive and negative bases of styrene and maeic anhydride mixed with equimolar ratio and PWC is made through proper heating, reacting, heat releasing and self-polymerizing. The mechanical properties and dimensional stability of PWC are significantly improved in comparison with that of plain timber. It is indeed a good method for timber modification and improvement of wood quality for fast-growing species.

Whether the log-dropout sorting system can be adopted or not by gravity for dropping out the logs eccentrically loading on toggles, it is of vital importance to its popularization and development. The theory of this system is discussed in this paper. It is verified by experiment and the formular for calculating the distance from the centre of log to centre Hne of the conveyor is given. Authors of this paper hold that all kinds of log can be successfully dropped themselves out along the ground when their centre of gravity is located inside the guide c (See Fig. 2).