A group of equations relating stand mean attributes to stand diameter cumulative distribution has been developed which can be used to build relations among whole stand model, size class model, and distance-independent individual tree model. These equations can be used to allocate stand gross basal area growth to each individual tree. Parameters in diameter growth and mortality models can be recovered using these equations and based on arithmetic mean diameter and quadratic mean diameter, therefore the compatibility between estimations from stand model, size class model, and individual tree model are guaranteed. An error function in the group is used to describe diffrentiation process of trees with the same diameter at initial stage and it has been proved that estimated diameter range will be smaller than the real one if such an error function is ingnored. Introducing this error function into the models improves the models' accuracy in predicting diameter distribution. An example is given to show the models' applicability.

Tree volume estimate of forest stand or sample plot by using the current one-way tree volume table is significantly biased, and on the other hand, the workload for measuring heights of sample trees in field is rather heavy if two-way tree volume table is directly used. To Dealing with counter this problem existed in practice, a new approach is presented in this paper that two-way tree volume table can be employed directly to estimate the volume of forest stand or sample plot based on the establishment of a variable relative height curve model. By using this approach, the precision of volume estimate is almost as high as that by using tree height curve, but in this case, it is not necessary to measure heights of sample trees, so the workload in field is reduced evidently. The general form of variable relative tree height curve model presented in this paper is: RH_i, =[1-e^{-f₁(${\bar D}$)})]^{-f₂(${\bar D}$)}*[1-e^{-f₁(${\bar D}$)*RD_f}]^{-f₂(${\bar D}$)}.

Phosphatidyl glycerol (PG) was isolated from leaves of different cold resistant varie ties of poplar and their hybrids, and phase-transition temperatures were determined by electronic spin resonance spectroscopy (ESR) method using Tempo [2, 2, 6, 6-tetram-ethylpiperidine-I-oxy1 (structure)] as the spin label. The fatty acid composition of their PG was analyzed by gas-chromato-graphy method. The results showed that PG from the cold-sensitive plant Cottonwood (Populus deltoides cv. ' Lux' I-69/55, female parent) underwent a thermotropic phase-separation at about 4 ℃. In contract, PG from the cold-resistant poplar Populus euramericana cv. I-45 /51 (male parent) went into the phase-separation state at about -12 ℃. PG from the six hybrids entered the phase-separation state at the temperature ranging from -2 ℃ to 11 ℃. The analyzation of fatty acids compositions in phosphatide suggest that saturated fatty acids level (the sum of palmiate plus hexadeca-trans-3-enoate plus stearate) as a proportion of total phosphatidyl glycerol fatty acids was closely related to the thermotropic phase-transition behavior of phosphatidyI glycerol from different cold-resistance varieties. The saturated fatty acid level of PG from cold-resistance plant was lower than that from cold-sensitive plant so that the phase-transition temperature of PG from the former was lower than that of the latter and displayed the cold resistance.

Mating systems in three populations of Masson pine (Pinus massonina Lamb.), including a clonal seed orchard, a plantation near the seed orchard and a clone bank were studied by isozyme analysis with the help of level starch gel electrophoresis. The results were as follows: the multi-locus estimate of outcrossing rate (t_m) of the seed orchard was 0.792 (se=0.062) (standard errors in parenthesis); the outcrossing rates (t_m) of clones in the central blocks and in the fringal blocks were 0.801 (se=0.075) and 0.800 (se=0.067), respectively; the estimate of t_m for the plantation near the seed orchard was 0.821 (se=0.188), while in the clone bank the t_m was 0.431 (se=0.131). It indicated that the outcrossing rates in this seed orchard were lower, which might be an important obstacle to increase the quantity and quality of seed. The paper discussed the main factors affecting the mating systems of populations. It analyzed the probable reasons for the low outcrossing rates of Masson pine and presented some suggestion for further studies in this area.

An investigation at Youxi and Yangkou seed orchard of Chinese fir from 1991 to 1994 has been made to study two cone crop prediction methods counting number of visible cones in crown from an observation point and counting number of cones in certain informative section of crown. Prediction models were developed for each method. The results verified at different seed orchards showed that the models could be used precisely and easily.

In 1989-1995, the natural population life table of zizyphus geometrid Sucra jujuba Chu was studied in Taigu County and Jishan County, Shanxi Province Based on the investigatory data, five yearly natural population life tables and one average life table in five years were developed The results showed as follow:1.All the survival curves from the life tables belong to Price's type A. 2. The trend index of one average population was 1.203.3.there was significant suppression effect of natural enemies on the larvae of zizyphus geometrid and the index of population control (IPC) was 5.793.4.The death of overwintering pupae was the key factor affecting population dynam-ics, and the pupals stage was the key stage.5. A prediction model for the larvl density of zizyphus geometrid was established.The accuracy rate of forecast as used in Taigu County and Jishan County in 1995 was more than 90% it is quite available for the control of this insect.

28 species of parasitic wasps of Dryocosmus kuriphilus were found in Shandong Province, which almost belong to chalcidoidea and ten of them are more important.A key to the species is provided.The parasitic wasps are either monoparasitic or polyparasitic, either protoparasitic or epiparasitic, either ectoparasitic or endoparasitic.4-5 species of them are more significantly affect the change of the population of Dryocosmus kuriphilus which occupy a certain niche in different environments.Torymus sinensis K.Which is the most important parasitic wasp leads the periodical change of population density of Dryocosmus kuriphilus.

Dioryctria yiai Mutura et Munroe is an important insect pest damaging 2-year-old cone of Pinus massoniana Lamb in China. The transfer damage of the overwintered larvae of the pest and its density estimate were studied on the basis of the reproductive charcteristics of the male flower of Pinus massoniana in seed orchard.The results showed that on the 7 whorls crown of host trees, the overwintered larvae distributed principally to 2-year-old cone of the 6th and 7th whorls, the rate of the cone damaged reached 53.6%, the percentage of the larvae reached 58.8% The larval damaged rate and the number of larvae increase with the increase of the inflorescence rate. The relationship between the darnaged rate of 2-year-old cone (y₁), number of larvae (y₂) and the male inflorescence rate (X) were estimated as y₁=0.660+0.473X, y₂=0.829+0.303X, respectively.

To study the mechanism of reaction between wood and crosslinking agent in compressed wood, lignin, holocellulose, cellulose, α-cellulose and hemicellulose were isolated from populus ussuriensis and reacted with melamine-formaldehyde.The distribution and reactivity of reacted chemicals in wood cell wall components were determined. The order of reactivity was found to be lignin > hemicellulose > holocellulose > α-cellulose > cellulose.The chemical construction of holocellulose, cellulose and lignin before and after crosslinking reaction were analysed.Using infrared(IR) spectra, thus the changes of main chemical groups of modificated wood were qualitatively determined.

Isoion spectrum, Fourier Transform Infrared Spectroscopy and Electron spin resonance spectrum were used to analyze chemical properties of the wood in different year-ring parts in this experiment.The results showed that there was a greater variation in chemical characteristics between wetheartwood and normal sapwood.Compared with sapwood, wetheartwood contained much higher ash and the inorganic elements such as K, Ca, Na, etc.It is evident that there were polyphenols acids, esters and free radicals which affected the colour and the water content in the heartwood.Moreover, it appeared that the characteristic of wetheartwood depanded mainly on the genotype of the clones.

The morphologic feature, growth and development, leaf screen and leaf biomass of four Ginkgo caltivars in China were studied in this paper, which were Kuijin, Mating 5^#, Jiafushou and Dongtinghuang.Leaves of Ginkgo are categorized:fan shape.semicircle shape and the heart shape.The heterophylly of Ginkgo is related with age of shoots and location of leaves growth.The phyllotaxis of cutivars are proved to be 3/8.The annual dynamic change in leaf length, leaf width, petide length, leaf area, dry and fresh weight of leaf can be expressed。"S"-shaped curves.Water content in leaves sharply declines as the leaves growth period prolongs.Length of long shoot is 583cm, numbers of leaves are 402, leaf area is 9735cm², fresh weight of leaves is 355g, leaf area index is 2.58 for a 3-year-old young grafted tree.

Schizotetranychus bambusae Reck is an important pest injuring the leaves of bamboo. The mite hibernates on fallen leaves.In the soil chink of the basis of bamboo and in the leaf sheaths as impregnated female adults.They move out in the first decade of April the next year and hibernate slowly in October.The period of each dcvdopmental stage is negatively correlated with temperature Ianged from 20℃to 30℃.The developmental peri-od of one generation is 20 days at 20℃, and 10.3 days at 30℃.The period of oviposition is the longest(17.8 days)at 20℃.Average egg number per female is the largest (28.0)at 25℃.The peak of oviposition is on 4-8 days after hatching.The effective accumulated temperature of one generation is 204.7 day—degree and the developmental zero is 9.6℃.

Cephalcia tianmua Maa is a forest insect pest injurious to leaves of Pinus massoniana Lamb.. It can cause defoliation on large areas when reproducing on a large scale. It hasone generation during a year, and the paiod of feeding is more than one month. It hibernates as prepupa in the soil and pupates and emerges in next spring.Natural enemies are significant factors for restricting its population increace.

Using the method of wood property analysing and sulphate pulp-making, we studied the chemical composition, physicla nature, pulp making process and pulp charactereistics, and pointed out the effect of age site condition, density and produdive region on pulp wood property, pulp making process and pulp charactereistics.It is shown that the wood property and pulp index of Larix olgensis pulp plantation which is elderthan 15 years old can satisfy the pulping and paper making.For cultivation short rotation Larix olgensis pulp plantation, we should harvest wood elder than 15 years after planting.The better the sitc condition and the more suitable the plantation desity, the better the wood propery, which would be beneficial to pulping and paper making But But the influence of site condition and population density on pulp physics intensity is not obvious.On the same condition the wood property of Larix olgensis pulp plantation in southe productive region is superor to that in north productive region.