The optimum nutrient requirements (macronutrients) for maximum growth rate of Paulownia elongata and Robinia pseudoacacia have been studied based on the principles of steady state nutrition, by using a growth technique that the nutrients consumed were compensated by means of daily determinations and adjustments of pH and conductivity titrition.The seedlings were grown under controlled conditions, the nutrient status in seedlings and its maximum growth rate remained stable during the experimental period. To obtain a high relative growth rate over 25% per day in Paulownia elongata and about 15% per day in Robinia pseudoacacia, suitable proportions by weight may be 100N:75K:18P:7Ca:8.5Mg and 100N:60K:15P:8Ca:9Mg respectively.The optimum nutrient requitements by weight and its perspective of applications in fertilizations of nursery and young forest stands were also discussed in this paper.

Based on the investigation of symptoms of the infected Chinese pine tree and the amount of their nymph, the infected trees are graded into four classes. There is in the ratio of 9:3:3:1 among the four classes of trees. The gradation is not related to the environment. There is a negative correlation between the tree growing capacity and the amount of the nymph, but not significant. The trees of class Ⅰ grow normally without symptoms. The difference of growth between Ⅰ and Ⅲ, Ⅳ class of trees is very significant. The symptoms occured on the infected trees which are six years old. If no symptoms occured on such trees they will not occur ever. The chances of infection will become much less when the trees are over 15 years old. For this reason, the age of stand in which the plus trees with the resistance are selected will be over 15 years old. By using the method of 5 dominant trees, the plus trees shall be selected among the trees of class Ⅰ and its DBH and H must be larger than the average by 15% and 5% respectively.

The dividing line of geographic distribution and morphological differences between Pinus henryi Mast. and Pinus tabulaeformis Carr. were studied by means of numerical analysis. Data were taken from 24 morphological trails of cones, seeds and needles in natural stands, which included the entire range of Pinus henryi Mast. and the southern part of the range of Pinus tabulaeformis Carr. The results show that the morphological differences between Pinus henryi Mast. and Pinus tabulaeformis Carr. are highly significant. It was confirmed that Pinus henryi Mast. and Pinus tabulaeformis Carr. Are indeed two separate species, and the dividing line of geographic distribution between them is located in the Mi-Cang Mountain to the Da-Ba Mountain.

Among several secondary metabolic products of Camellia oleifera the injury of saponin to Colletotrichum camelliae is the severest at 200-400μg/ml concentration, but the concentration is so high that it is indicated that saponin can not be regarded as physiologically active substance. However, after saponin is hydrolyzed by 6N HCl and forms sapogenin, the injury of sapogenin to C. camelliae is severer than saponin, for example, 0.05 mM saponin causes increasing of amino-acid which is leaked into medium by C. camelliae mycelium at 0.43 times more than control, and 0.05mM sapogenin causes increasing in amino-acid at 16.86 times more than con- trol. The leakage of large number of amino acid results in death of C. camelliae mycelium. Therefore Camellia oleifera sapogenin is the main compound to inhibit C. camelliae. In plant, saponin transforms into sapogenin, that is resulted in catabolized reaction by β-glucosidase. The experiments in vitro demonstrate that Camellia oleifera saponin transforms into sapogenin by β-glucosidase, and sapogenin injures C.camelliae and brings C. camelliae mycelium to leak off aminoacid. Therefore it may be conjectured that the metabolic process which saponin transforms into sapogenin by β-glucosidase will play an important role in resistance of Camellia oleifera to C. camelliae.

Three strains of Bacillus thuringiensis were isolated from the larvae of Dendrolimus sibiricus, Pyralis farinalis and from forest soil. The parasporal crystals of the strains were examined by electronic microscopy, wich showed three kinds of form: the bipyramidal and mosaic the cuboidal and the irregular. The biochemical characters of the three strains and esterase analysis of vegetative cell were examined. The three strains showed different toxicity to the test insects.

A survey of ectomycorrhizal fungi was carried out under 7 chief forest types in alpine coniferous forests between altitudes from 3000 to 4000 m. in the northwestern part of Yunnan Province in Summers of 1985 and 1986 by use of method of observation in standard stands. During the 2 years, 26 stands were investigated, which were grouped into 7 forest types. Under these forests were also collected more than 500 higher fungal specimens, 140 ectomycorrhizal specimens and 20 soil samples. There are 33 genera about 140 species of ectomycorrhizal fungi listed under these 7 forest types. Their distribution shows a certain regularity, it varies with the tree species, soils and topographic factors, such as altitude, aspects, slope position and steepness of slopes. The common ectomycorrhizal fungi presenting in all the forest types are those of genera Amanita, Cortinarius, Russula, Lactarius, Laccaria, Cantharellus, Boletus and Suillus, but their species and abundance in the different forests may be different. this paper is also attached a list of ectomycorrhizal fungi and their distribution under these 7 forest types.

This artical is focused on the relationship between the effects of water and soil conservation and vegetation. The results are as follows:Ⅰ. The recovery increments of vegetationIn mountainous area:On the northern slope is 9.2% / per year, on the southern slope is 9.0% / per year.In hill area:On the northern slope is 8.3% / per year, on the southern slope is 7.6% / per year.Ⅱ. The increasing effects of vegetation on runoff are as follows:1. Shortening the process of runoff, 2. Lowering the peak of flow, 3. Increasing the permeability of the soil, 4. Lessening the amount of runoff.Thus when vegetation increased 1% the coefficient of runoff would be decreased 1.04— 1.2% accordingly. If vegetation increased to 90%, the runoff would be fundamentaly controlled.Ⅲ. The relationship between vegetation and the soil surface erosion are as follows:The relationship between vegetation and soil surface erosion is in inverse proportion.When vegetation is less than 60%, the curve of the soil surface erosion prets a elevation manner by a 45° angle. When vegetation increases to 90%, the soil surface erosion is basicaly controlled.

According to the structural parameters of GJ-85 chain saw made domestically, a series of imitating tests have were been made by using dual regression orthogonality test on the test table. The relationships between cutting power, cutting productivity, the consumed energy per unit-area and cutting speed of chain, cutting force and cutting length have were been obtained by analysing and treating the measured data, according which, the best match parameters have were been found out. The theoretical basis of improvement and the conditions of reseanable application have were been put forward to the GJ-85 chain saw by analysing and calculating.

Warty layers on the inner surface of tracheids in 11 families, 41 genera, 99 species of the Chinese gymnosperms were observed systematically. Present or absent, distributing densities, sizes and shapes of the warty layers are some valuable for the classification of families, genera and even species of the gymnospermous woods.1. Warty layers on the inner surface of tracheids have been found in concentrating in Taxodiaceae (except Taiwania, Taxodium, Metasequoia), Cupressaceae (except Thujopsis, Thuja), and Keteleeria, Abies, Tsuga, Cedrus, and part of the species in Pinus of Pinaceae, but have not been observed in Podocarpaceae, Cephalotaxaceae, Taxaceae (except Pseudotaxus, Torreya), and Pseudotsuga, Picea and Larix of Pinaceae.2. Warts in Pinus bungeana are more bigger than the other species of subgen. Strobus. There are distinct warts on the inner wall and rare warts on the border of pits in their tracheids. Based on its anatomical characteristics of wood, chemical composition of heartwood and strure of needles, suggestion may be proposed that P. bungeana would be promoted from Sect. Parrya to Subgen. Parrya.3. Within an annual ring, the warts diameter of latewood tracheids were generally larger than those in earlywood tracheids and their distributing density was in decreasing. And less difference was found in size and distributing density of warts between both the radial and tangential walls of a tracheid.4. When wood sections (12 species) were treated with 0.5% sodium hypochlorite, the warts of 7 species on the inside of tracheid lumens decreased 57%, its distributing density decreased 52%. The warts have not been seen in the other 5 species.5. The warty layers (in 6 species) also can be dissolved by white rot and some soft rot species.

The properties of particleboard used as substrate for overlaying with a single sheet resin impregnated decorative paper should have some differences from those specified in GB4986-4905-85 for general uses. Most grades of the domestic commercial particleboards have atained or even exceeded the specification class 1 of GB4986-4905-85. However, if any particleboard manufacturer attemts to use their own products for the above mentioned type of substrate, it is necessary to regulate some of their properties. The most important point is to decrease the thickness tolerance of the unsanded particleboard. Particles for surface layer must be fine enough because micro-particle fraction is much necessary on the board surface. The appropriate density of this type substrate should be around 0.68g/cm³, within the range of 0.65g/cm³—0.73g/cm³. There would be no considerable difficulties to produce this type of substrate by the present domestic particleboard plants, especially in those having the scale of 30,000 to 50,000m³/year.

In order to overcome the difficulties of drawing design and counting the number of seedlings, the author thinks it is better using the patten of mixed forestation instead of the drawing. The patten contains two parts, namely, elementary and composing pattens, the fomer includes the pattens of mixed in line, in belt and in blocks, the latter can be make up according to the elementary pattens, the formula of the number of seedlings have been given, three examples using the pattens also have been given.

Because the tree-crown of mean wood assortment in China are obviously greater, the numbers of trees in a stand are counted by projected areas of tree-crown of dominant trees, the trees above mean trees and double indexes, mean trees, all trees of a stand (N=10000/(π/4)(CWD)², CWD--diameter of tree-crown). Except special kinds of trees, the numbers of trees are different greatly with greatest density of stand. Form the above, the conclusions can be drawn: It is lack of fully theoretical bases that the numbers of trees counted by projected areas of tree-crown are as greatest density of a stand.

In this paper, the germplasm resources, classificatory distribution, as well as ecobiological characteristics of Hippophae in Gansu province have been investigated. Three species and two subspecies have been found in Gansu, named H. rhamnoides subsp. sinensis; H. rhamnoides subsp. turkestanica, H. neurocarpa and H. thibetana, and described from morphological characters to contents in fruits uspectively. Meanwhile, the relationships between its distribution and elevation, air temperature, and precipitation have been analized. It is shown that Hippophae L. is a kind of water loving, sun deciduous trees, resistant to drought, cold and barren. According to its ecobiological traits, the Hippophae growing areas in Gansu can be divided into following three districts: 1) Gannan-qilianshan district; 2) Hexi desert district; 3) Lanzhou and east of it district. As its dioecious pollination and facultative vegetative propagation, Hippophae is rich in germplasm resources so that it is necessary to build up specific plantations for its utilization propect, thus some good ideas about how to protect, further develop it, and strong then research work also been propounded in this paper.

The author chose 45 OTU' s (namely 45 poplar rusts species) from the world, and chose 24 non-redandant characters in Uredinia, Telia, hosts and alternate hosts of these 45 OTU's. The operational basis of numerical taxonomy as presented by Sneath and Sokal. In this study 24 non-redundant equally weighted qualitative or qualitative characters representing 45 OTU's were entered into a basis data matrix, Cluster analysis (UPGMA) and principal component analysis (PCA) were produced from the original matrix. The results of UPGMA and PCA are the same, and show that 45 OTU's are classified into 14 groups. It means there are 14 poplar rusts species in the world. The 14 species are the following:1 M. pruinosae Tranz. 2 M. laricis Hartig. 3 M. pinitorqua Rost. 4 M. pulcherrima Maire. 5 M. magnusiana Wagn. 6 M. rostrupii Wagn. 7 M. abietis-populi S. Imai ex S. Ito 8 M. medusae Thuem. 9 M. abietis-canadensis (Farl,) Ludwig. 10 M. occidentalis Jacks. 11 M. ciliata Barcl. 12 M. microspora Tranz. 13 M. larici-populina Kleb. 14 M. allii-populina Kleb.The present paper gives the difference of some similar species. The author also discuss the affinity of the species and the evolution of some species, and think that it is very important to know all the poplar species and the affinity of them for the poplar introducing and the poplar resistant breeding.