During the period 1987-1988, 6 plots representing 5, 10,and 20-year-old Chinese fir stands with good and poor site quality were laid out in Fudong Branch of Fengshushan Forest Station,Jiangxi province,and the differences of chlorophyll, arginine and ammonia nitrogen contents in needles and twigs of different tree classes among the stands of different ages on various sites during different seasons were studied. There were significant differences in chlorophyll content in needles during bud flush and pre-dormancy among the stands of different ages, but insignificant during fast-growing seasons.Chlorophyll content in needles during fast-growing seasons was much higher than that during bud flush and pre-dormancy,especially during the second fast-growing season. It was generally higher on the good sites than that on the poor sites during all seasons in all stands. It reached 2.50,2.24,and 2.14.mg/gf.w.in the needles of dominant trees on the good sites in 5, 10,and 20-year-old stands respectively. There were significant linear relationships between chlorophyll contents in needle during bud flush,the first and secondfastgrowing season and corresponding nitrogen concentration (r=0.86, 0.76, and 0.81 respectively). Chlorophyll content can be used as a physiological index to evaluate nitrogen nutritional status in Chinese fir plantations. Arginine and ammonia nitrogen contents in current needles and twigs on the good sites were higher than those on the poor sites. Arginine contents in current needle were 47.55, 43.37, and 29.44mg/100gf. W. during the second fast-growing season in the stands of 5, 10,and 20-year-old respectively,while it were 28.16, 26.42,and 14.95mg/100gf.w. on the poor sites.

This paper reports the research results of fertilization of the grated seed orchard of Chinese fir (Cunninghamia lanceolata Hook.) in Dongan, Hunan province. The results revealed that it was the best plan for fertilization to improve the production of conelets that each tree was spreaded 0.2kg ofpotassium chloride, 0.4kg of urea and 0.3kg of superphosphate in every middle 10 days of March, June and August. The seed quality by fertilization was not obviously effected. Analyses of nutrient elements in needles and soil showed the reason why the seed production was so low in the orchard was that Mn content was too high and B content was deficient. It was suggested that lime should be added to the soil and B be spraied on the foliage, and the mostsuitable period for spreading N, P, K fertilizers was from March to August in a year. The desirable period of collecting leaf samples for nurtientdiagnosis was August. It was found that the critical values of different nutrient elements in the needles were N 0.8%, P 0.2%,K 0.7% with the suitable ranges N 0.8-1.2%, K 0.7-0.9%. Ploughing and weeding could not significantly improve seed production of the orchard.

To identify hybrid vigour how to resist insect damage, a research project was carried out with Pinus thunbergii,p. densiflora,P. tabulaeformis and some natural hybrids between these species in the areas where Matsucoccus matsumurae Kuwana had occurred through comparison in morphology and growth,PCA and peroxidase isozyme analysis. Two hybrid types, 'black densiflora'and 'black tabulaeformis', Were selected. Ten-year old trees of these two hybrid types were at all not attacked by the insect, in contrast, P.tabulaeformis and P. densiflora, which were used as control in the experiment, were damaged at rates 22.9% and 30.7% respectively. These two hybrid typesselected could be extended for commercial plantings to the central and eastern parts of Liaoning Province, China.

Based on the extensive data collection of phenology of Chinesefir(Cunninghamia lanceolata Hook.), geographical variation of phenological phases in Chinese fir was analysed and it was found that there was a correlation between the productivity, and growing period. The main results were asfollow: (1) the indication of geographical variation of phenological phases of Chinese fir, and the establishment of mathematical models of mainphenological phases patterns of geographical variation of Chinese fir.(2)demonstration that there was a square curve correlation between length of growong period and productivity, when the length of growing period was in anarrange of 200 to 250 days (mid-zone), the productivity was higher, resching 8-18 t/ha.a; while the length was more than 250 (in south-zone) or less than 200 days(in north-zone), the productivity was lower,only 3-8 t/ha.a.These rgsults were effected synthetically by eco-genetic characteristics of Chinese fir and the environmental conditions.

Bioassay of four Escherichia coli of experessing Bacillus thuringiensis δ-endotoxin gene against forest pests (Lymantria dispar, Apocheimacinerarius, Dendrolimus punctatus, Clostera anachoreta) showed: The four cloned strains had high toxicity against above-mentioned pests and could inhibit growth and development of the pests.

The osier weevil is a wide destroyer of poplar in some parts of the world.This pest is mainly controlled by using conventional pesticides atpresent. These pesticides not only pollute the enviroment, but also cost a lots.From 1987 to 1990, the oil solution and flowable oil colloid ofbenzoylphenol uera No. 3, which are safe, high effective and low cost, weremanufactured, and the spot treatment and hole block methods were used in thecontrolling of the osier weevil in the larval and the adult stages. Themechanisms of the effect of benzoylphenol urea No. 3 on the larva and the adult of this pest is discussed. Experimental results showed that comparing with the larvae of untreated group, more than 15 per cent chitins in theendocuticle of treated larvae was reduced. The spraying of 15%-25% of flowable oil colloid of benzoylphenol urea No. 3 made the ovary and the testis can not develop, and the number of eggs laid by the treated hatching rate of those eggs became zero. The oil solution and flowable oil colloid ofnenzoyphenol urea No. 3 can be effectively used in the control both of the larva and the adult of the oser weevil. The use of these insecticides opens a new way for the control of the osier weevil.

Lathrostizus shenyangensis, sp. nov. (Figs. 1-6)The new species is similar to L. lugens (Grav.) and L. flexicauda (Holm.),but it can be distinguished from L. lugens by the characters: Clypeus nearly flat, antenna 30 segments, postpectal carina straight or with a very weak notch in the middle and not raised near the notch; from L. flexieauda by the characters: Ovipositor very strongly upcurved, gaster of female mostly redbrown.Holotype: , Shenyang (41.6°N, 122.8°E), Liaoning Prov. 12- V-1992,Xu Gongtian. Paratype: 14, 8, the same data as holotype.Host: The larva of Pteridea sp. was collected from Salix babylonica.The holotype is kept in the General Station of Forest Pests Management,Ministry of Forestry; the paratypes are kept in the above mentioned General Station and Shenyang Administrative Office of Green Planting.

Two kinds of egg parasites Ooencyrtus kuwanae (Howard) and Anastatus japonicus Ashmead of gypsy moth Lymantria dispar, were studied in Beijing area from 1987 to 1988 O. kuwanae and A. japonicus has 4 - 5 and 2 - 3generations per year on gypsy moth eggs respectively. The parasitism varied with the dates of the egg masses collected, from 0.64-0.66% of A. japonicus in the eggs collected in late July to 2.26-4.18% in the eggs collected from middle July to middle August, for instance. The adult of these two egg parasites emerged in a two-year period. The emergence rate of O. kuwanae and A. japonicus were 99.35%, 81.0% and 0.7%, 19.0% in the current year and the next year respectively. For the purpose of the preservation of these two egg parasites,the best time to remove gypsy moth egg masses as a control measure is from late September in the current year to late March of the next year.

A time-dependent Markov model was developed to predict diameter growth of mountain ash(Eucalyptus regnans F.Muell) plantations. Themodel was established using data from a Nelder espacement trial. Thecomponents of diameter growth was based on multinomial logit regression using two-stage generalized least square procedures: The first stage comprising regressions of diameter transition probabilities against logarithm on stocking and age for each diameter class and the second relating the first stagecoeficients to diameter. Comparisons between this model and conventionalmethods (variously Normal, Weibull and Sb distributions) were made and it was showed that the time-dependent Markov model was markedly acclurater than the others. This time-dependent Markov model could be used to predict diameter growth for plantations with site index range 28-44m.

The general goal of macro-controling the timber circulation is to implement the inside reform of the forestry department, based on the social founctions of forestry performed well. The subject excuting the macro-control is an adminastrating system headed by forestry department with other relevant adminastrating departments, and the object is the present timber market.The whole system runs as follows: the subject draws up policies according to the goal of macro-control and makes the object under control by suitable measures, and the effects are sent back to the subject to adapt the policies.

The effect of steaming on the permeability of spruce (Picea jezoensis var. komarovii), fir (Abies nephrolepis) and pine (Pines koraiensis) woods were studied. The green and air-dried specimens (2 ×2 ×5cm) for treatment were steamed at 120℃(1kg/cm²) and 100℃ (1kg/cm²) for 8 hours under water vapor saturated conditions and then subjected to air-drying untill about 10% moisture content. A rising-water volume-displacement method was used to measure air permeability in the longitudinal direction of the wood. The gas permeabilities of the steamed specimens were compared with those of matched unsteamed controls (m. c. ≈10%). The result showed that the effect of steaming on the permeability of wood is variable due to that the change of wood structure and chemical composition caused by steaming is not the same in different wood species with different properties. The average permeability of steamed at 120℃ and 100℃ air-dried pine sapwood and heartwood was increased by approximately 60%, 90% and 40%, 130%respectively. The average permeability of steamed at 120℃ green sprucesapwood and steamed at 100℃ air-dried spruce heartwood were increased by approximately 326% and 80%. The increase in permeability of steamed wood was attributed to produce crack in pit membrane and torus after steaming.Paired comparison analyses (t) were carried out between the steamed and the matched unsteamed specimens. Significant was at the 90-99.9% level.However, steam treatment had no effect on the permeability of steamed green spruce heartwood, air-dried sapwood and heartwood, as well as steamed green fir heartwood, air-dried sapwood and heartwood.

Bamboo forests are widely distributed in the subtropics of China. Agroforestry systems have been recommended, e.g. raising cattle in bamboo stands, to enhance the economic return. A Bamboo-Cattle-Grass agroforestry system has been designed to explore the feasibility of that kind of systems.Data were collected from the experiments conducted in Dagangshan, Jiangxi province, and a simulation model was developed. Productivity, cost,economic return, impacts of crown density on undergrowth, impacts of cattle on volume weight of soils etc.and feedback loops among them were taken into consideration in the model. Seven scenarios are set up based on cut-age of bamboo stands. The results show that as the crown density becomes lower the economic return grows up, but a disastrous ecological impact follows.The soil is compacted by cattle and low carrying capacity and serious land degradation will happen.Introduction of quality grass species and cage-feeding method can much improve the productivity of grass and soil conditions,but the economic return is not high. Neither grazing under canopy norcagefeeding of cattle favoures the improvement of economics of bamboo regions.If appropriate techneques and markets are available meat-targeted ormilktargeted cattle in cage-feeding may be profitable. However, these conditions are generally not available in the present bamboo regions. The later policy may have hopeful perspectives. A successful evaluation needs a futhersocial-economic-production model.

A simple, rapid and very efficient methord is discribed for nucleic acid extration, purification, reannealing, and hybrization of pines. The procedure can widely be used for analyses of plant nuclear DNA, especially for conifers in a simply-equiped liboratory.

The larvae of the red-headed blister beetles can eat the eggs of the bamboo locust (Ceracris kiangsu), and the adults of these beetles like to eat the leaves of paulownia trees. It is a good idea to use the red-headed blistel beetles to control the bamboo locusts.So far two species of the red-headed blister beetles have been found in Jing'an county, Jiangxi province: one is Epicauta ruficeps Illiger, the other is Denierella serrala Kaszab. The adults of the beetles lay eggs in the same place as the locusts do. One larva of the red-headed bliter beetle can eat up an egg mass of the locust.It is recommend that paulownia trees are suitable to plant at the foot of the hill where bamboo grows or in the open places of the bamboo forest or along the roads near the forest. The number of paulownia trees planted is 2 in 10 mu bamboo forest. Paulownia trees can lure many red-headed blister beetles in three years after they are planted, and in 4 or 5 years the outbreak of the bamboo locusts will be controlled.

The adults Apriona germari (Hope) were separately fed on shoot bark of paper-mulberry and Populus deltoides cv. "Lux" Ⅰ-69/55. The results of feeding showed that the average longevity of female adults fed on shoot bark of paper-mulbety was 74. 2 days longer than that fed on shoot bark of poplar, and the average longevity of male adult fed on shoot bark of papermulberry was 58.8 days longer than that fed on shoot bark of poplar. The female adults fed on shoot bark of poplar could not lay eggs. Planting paper-mulberry in poplar plantation to attract and kill adults of Apriona germari (Hope) and clearing away paper-mulberry. And mulberry tress within 500m around poplar plantation were proved to be effective. The percentage of trees infected by larvae in poplar plantation with planted paper-mulberry as attractive trees was lower than that of control plantation by 61. 6% after two years. The percentage of trees infected by larvae in poplar plantation cleared from mulberry and paper-mulberry was lower than that of control plantation by 42. 3%-77% in the year of question.

In this paper, we studied and analysed the idle vibration state of the Woodworking Single-side Thick-nessing Planer by using the MB 106A as a experimental machine, so we got the vibration accelerating values of the worktable,the distributive rule of the worktable vibration values. We also founded out the main vibration sources of the machine. This paper provided experimental data for the dynamic design of the Woodworking Thicknessing Planer. And it will provid a efficient way for the vibration research of the similar machine tools in the future.