Eucalyptus, extensively used in fibre industry, occupy perhaps one fifth of the world's man-made forests. The output of wood of this species is one of the three chief tree species in the world. In quest of rapidly breeding tissue culture technique of Eucalyptus has been tested and many rooted plantlets had been regenerated from organ culture and callus culture, but the plantlets induced from embryoid has not been reported yet.Our Institute has been succeeded in inducing the cellular masses culture into embryoids. The materials used are from plus trees №.46 and №.9 of Eucalyptus "leichow №. 1". In the same embryonic cellular mass culture, the unsynchronous embryoid fromation, such as spherical proembryo, heart-shaped embryo, torpedo-stage embryo, embryonic root and embryonic bud, could be observed. The embryonic cellular mass culture was deep red in color, bound together in structure, unever and superficially granulated. They are very active when transferred to subculture, it would increase 10-30 times and further differentiate into numerous rooted plantlets. The plantlets are very easy to be transferred to the soil.

The effect of improving the eco-environmental factors of a crop field by a network of shelterbelts is investigated and compared with that of a single shelterbelt. The effect of promoting the growing, development and yield of crop (wheat) was analysed also. The result of analysis is given as follows: (1) The effect of a network of shelterbelt is 10% higher than that of a single belt. (2) The variation of wind direction casts no significant influence on the improving effect of a net with a shape of approximate square. (3) The region of shading effect of a shelterbelt is confined within a distance of 0.5 height of the belt. (4) An effect of lengthening the periods of the nutritive growing and the accumulation of meterial of grain was investigated. (5) The yield of crop was increased by about 5.5%.

This paper presents the studies of the bionomics of the Yunnan pine bast scale, Matsucoccus yunnanensis Ferris (Homoptera: Coccidae). The results of the studies are summarized as follows:1. The scale insect causes a serious damage to Pinus yunnanensis Franch.2. The insect has two generations a year in the area of kunming, Yunnan. The two generations overlap each other. In the whole year around various stages of the insect, from eggs to adults, occur in the said area.3. It is found for the first time that the insect undergoes the parthenogenetic reproduction in both generations of its life time. Its allied species, Matsucoccus pini Green undergoes parthenogenetic reproduction in England only in the first generation but not in the second generation.4. The insect lays eggs intensively in the early and middle period. It could lay eggs continuously several days at day and night time. Most eggs are laid during 5—12 P. M. and 1—8 A. M. On average, 104—189 eggs are laid by a female.5. The degree of infestation of the insect is more serious in the pure forest than in the mixed forest.

Cytology of mycelia, aeciospores, and aeciospore germ tubes of Korean pine (Pinus koraiensis) blister rust, Cronartium ribicola J. C. Fisch., were studied by the phase contrast microscope. The rust mycelia in the cortical parenchyma of the pine host bark, examined in paraffin sections, had one nucleus per cell. Mature aeciospores were usually binucleate. Upon germination, spores produced non-septate branched or unbranched germ tubes. Germinating spores usually produced one germ tube. No nuclear divisions occurred, and the two nuclei migrated together towards the tip of the germ tube. No appressorium and infection peg were observed at the tip of the germ tube. This type of nuclear behavior and germ tube growth is characteristic of host-alternating races, and it is distinguished from pine-to-pine races. Finally, the nature of heteroecious phenomenon of the Korean pine blister rust is also briefly discussed.

The white fly Aleurotrachelus camelliae Kuwana is one of the most destructive pests of the oil tea tree Camellia oleitera Abel. in China. There is one generation per year in Cheking province. The larvae overwintered on the leaves of the oil tea tree. The adults emerge and oviposit in April. Hatching occurs in late June. The larva has two instars and the second instar causes serious damages to the oil tea tree. Field survey showed that the fungus Aschesonia sp. Had a great pathogenecity to the first instar larvae.Spraying 25% imidan emulsion with a dilution of 1:2000; and 50% malathion emulsion with 1:1000 in late June to late July gave good results.

The purpose of site classification is to predict productivity and to devise an accurate choice of planting area in order to achieve better yield for Chinese fir.In the period of 1978—1980, the site type is classified and the potential productivity of Chinese fir is properly estimated in some of major planting areas. In this paper, surrey data of southern proveinces for Chinese fir are summarized to cope with the complexity of natural environmental condition in each surrey area a multiple-factor method, integrating with geomorghology, feature of bedrock, local topography, soil and Chinese fir growth is established. The type district, type subdistrict, type section and site type are determined based on above-mentioned factors respectively. A vast amount of surrey data also showed that the classification system is quite suitable for the conditions of Chinese fir forest and it may be used in the silviculture practice.

The flower-bud initiation of Chinese fir was studied in Nanpin, Fujian. The materials in this study were collected from five-year grafting tree in the seed orchard in 7—10 day's intervals beginning from summer of 1978 to spring of 1979 and repeated the collective from summer of 1979 to spring of 1980. The paraffin-microton-sectioning method was used in the study. The result are summerized as follows:It was found that male cone primodia of Chinese fir started to differentiate at the last decade of June. The microstrobilus primodia appeared to differentiate in the first ten days of August. Then the microstrobillus differentiated out the microsporophyll and microsporangium in the last decade of October. Mother-cell of microspore formed in January next year.The ovulate strobilus primodia of Chinese fir appeared to differentiate in the first ten days of August. It is two month more later than the male cone. Bract scale formed at the middle of October. The ovuliferous scale primodia differentiated at middle of December and ovule primodia differentiated right after it in the first ten days of January. The ovule formed in eary February.

Cuninghamia Ianceolata Hook. Is an important timber tree in China and has been widely planted in subtropical region of China at least over 500 years. However, a very large part of the Chinese fir has been planted in unsuitable sites in recent years, as a result, many of the stands are of poor growth. Therefore, it is of special significance for us to investigate the climatic regions for Chinese fir growth areas, so as to study the potentiality for the production of Chinese fir in different areas. At the same time, the suitable areas for producing commercial timber should be determined, the principle of culture practice provided too.The principle of component analysis (PCA) has been applied in this study. Seven variables of water and heat factors relating to growth of Chinese fir have been chosen from 131 weather stations within the range of Chinese fir, ie mean annual temperature, average january temperature, average july temperature, the months of mean month temperature above 15℃, the months of mean month temperature 20—26℃, arerage annual precipitation, months of month precipitation below 100mm. And computation was done by electric computer. Results of PCA are shown clearly to have discontinuous 6 groups and its two dimensional ordination by PCA can attain 74% of the total information content. Accordingly, the range of the Chinese fir is divided into three zones and six regions, namely, eastern region of northern zone, western region of northern zone, eastern region of central zone, middle region of central zone, east-southeast region of central zone, and only one region of south zone. The productivity of Chinese fir varies notably in different zones of regions.

The truck train consisted of universal truck and semi-triler for the treelength transportation is equipped with carting beam.Itis very important to set the optimum location of carting beam, which would realize rated load of the front and the rear axles under condition of full load, static state and flat rood, thus making truck develop the highest efficiency. It is under the direction of said idea that this paper, considering the circumstances in which the technical eguipments for log transportation are installed on the trucks and the down-grade characteristics hauling direction on forest road in China, proposes by the principle of mechanics a formula with the help of which the optinum location of carring beam can be determined, and presents some examples of calculation.

Dehydroabietylamiue and its acetate are new optical resolving agents with the advantages of low cost, less toxicity and high efficency. They are prepared from disproportionated rosin through amination, hydrogenation, salt formation and alkaliuation.Their physical constants and IR spectra conform to those given in the literature. Their resolving power for dl-2-(6-methoxy-2-naphthyl) propionic acid, an intermediate of a new medicine "Naproxen", has been proved satisfactory.

In order to study the possibility and precision of the early growing forecast of Pinus sylvestris var. mongolica annual increment in height and diameter has been measured actually to 1500 stocks according to different site and types in plantation of P. Sylvestris var. mongolica with 14 and 25 ages. We also have computed coefficients of correlation of annual inorement of height with diameter age-grade. Results have shown that coefficients of correlation are greater when it grows both in early and later ages. Almost completely have arrived quite evident level in statistical test. Besides have done stem analysis to plus trees and their dominant trees of P. Sylvestris var. mongolica for confirmation result about the comput to coefficient of correlation.Conclusions show that early growing forecast of P. Sylvestris var. mongolica in the Jing Yue Tan is reliable and feasible. It was important that factor of forecast may select height of tree. Forecast was possible form 5 to 25 years.

Numerous scientific investigations and field experiments have been carried out over the past 16 years in the introduction of olive trees from Mediterranean countries to China. Major achievements obtained including:(1) Areas adaptable for growing olive trees have been found. Field trials conducted in 16 provinces, municipalities and Autonomous regions as well as in thousands of experimental plots indicate that for the development of olive trees, the most favorable for growing are located in the south of the Chinglin Ranges, the northern slope of Da Ba Shan Mountain, western Hupeh and areas of low hills of the three Gorgies of the Yangtze River. Maximum annual yields of fruit for a single tree at 10—15 years of age average 737kg (5529.5kg/ha) in four year period. This represents a production of edible oil in the order of 1150.5kg/ha. The temperature and rainful in this region, particularly the annual distribution of precipitation and length of solar radiation comparatively suits their growth. Furthermore, there are suitable growing areas and the surrounding districts.(2) New cultivars and strains have been breeded. Plus trees (elite) such as Midxj-Jiu-Feng, Frant-oio-Feng 2, etc. have been selected from introkuced regions thus formed our own cultivars: through selection of the most superior trees from the seedlings, strains, new cultivars have been produced such as Zhong Shan₂₄, Yun Tai₍₁₄₎ Cheng-gu₍₃₂₎ etc; and new hybrids between cultivars and species have now being tried.(3) We first worked out the culture techniques suitable to our natural conditions. In view of the climatic conditions in our subtropic region differs from that of the Mediterranean countries, Particularly the rainful distribution and lengthe of sunlight, as well as the soil conditions. The results of study revealed particular attention should be given to the drainage in raining season and soil loosening, regulation of pit and application of boron, phosphorous, calcium and manganese as fertilizers, dwarf tree forms and prunning, These culture techniques are particularly suitable to our conditions.Research also reveals not only the introducion practices would be considered from the point of view of its climatic analogy, but also not limited by it. This is because the genetic character must be remolded through scientific treatment and different culture technique should be taken according to field local conditions.