Based on study of component,structure,function of degraded Karst forest in the natural restoration process in Maolan National Reserve of Guizhou Province,three evaluation indexes such as restoration potential degree (RP),restoration degree(RD),restoration speed(RS) and their calculating methods were proposed.Variation and comprehensive evaluation of RP,RD and RS of community feature indexes which reflected component,height,coverage,seedlings/total trees,dominance and biomass were analyzed.The results showed that there were the highest RP between the lower and the next to higher succession stage,so as that natural restoration of degraded community was a process in which lower community was replaced by its next higher one successively.There were higher RP but lowest RD and slower RS in the early stage;the highest RP,the fast RS and moderate RD in the mid-stage;the lowest RP,the slowest RS and the highest RD in the late stage.The RP of community was slower than that of community feature indexes,and the RS of total function was slower than its part one.In community feature indexes,RS of component,height,coverage,seedlings/total trees and dominance were faster than that of biomass,the fact indicated that RS of structure was fast than that of function.The natural restoration strategy was that the regeneration in early stage changed into the community structure adjustment in mid-stage,and finally to the structure and function coordination or improvement in late stage.The normal community component,physiognomy,structure could be presented after 40 to 50 years natural restoration,but it take a long time to restore total community function.

Plant communities in Baotianman,Henan Province were studied by the methods of Two-Way INdicators SPecies ANalysis (TWINSPAN) and Detrended Correspondence Analysis (DCA) in this paper.The results are as follows:Plant communitites were classified into 23 formations by TWINSPAN,they are Form.Quercus acrodenta, Form.Carpinus cordata,Form.Ostrya japonica+Kalopanax septemlobus,Form. Q.variabilis+Platycarya strobilacea,Form.Q.variabilis,Form.Q.variabilis+Castanea seguinii,Form.C.seguinii,Form.Q.aliena var.acuteserrata+P.strobilacea,Form.Q.glandulifera var.brevipetiolata+Q.aliena var. acuteserrata,Form.Populus davidiand + Betula platyphylla From.Q.aliena var.acuteserrata,From.P.strobilacea+Toxicodendron verniciflnum+Acer davidii,Form.Q.glauca,Form.Rhododendron purdomii,Form.A.robustum+Fraxinus mandshurica,Form.Macrocarpium officinalis,Form.Koelreuteria paniculata,Form.Catalpa ovata+Pterocarya stenoptera,Form.A.oblongum,Form.Pteroceltis tatarinowii,Form.Vitex negundo,Form.Dipteronia sinensis+Tapiscia sinensis and Form.Euptelea pleiospermum. Results of ordination by DCA reflect basically the relationship between plant communities and environmental factors,axis 1 and axis 2 reflect mainly the thermal and moisture gradients respectively.

Based on quantitative analyzing the economic benefits and fixed position measuring the indexes of soil fertility, regeneration of cut woodland and water and soil preserving, using Multi objectives Decision and Analytic Hierarchy process, the comprehensive benefits(economic and ecological)of different harvesting and cultivating operation systems were calculated in this paper. The results showed that the operation system which composed by 40% selective cutting, skidding by man force, removing slash in strips and natural regeneration with man promoting is the optimum model for natural secondary forests of Masson pine. The model is suitable to be used in the north of Fujian Province and other similar areas.

The spatial characteristics of distribution for 16 major tree species (genus) at NECT which is basically a gradient driven by moisture were studied by geostatistics and fractal methods.The patch size for Populus davidiana,Qucercus mongolica,Acer mono and Betula platyphylla were about 372 km,but the patch size for Pinus koraiensis,Phellodendron amurense,Betula costata,Tilia spp.,Juglans mandshurica,Ulmus spp.,Fraxinus mandshurica,Fraxinus rhynchophylla,Betula dahurica,Picea spp., Abies nephrolepis,Larix spp. were less than 10 km.The distribution of tree species(genus)were figured out by kriging.Betula dahurica,Populus davidiana,Tilia spp and Qucercus mongolica were distributed in the whole study area from 130°E～131°E so that they had strong drought tolerance,however,Larix spp.,Abies nephrolepis,Picea spp.,Betula platyphylla,Acer mono,Betula costata and Pinus Koraiensis were located in 126.6°E～131.3°E so that they had strong drought intolerance.Phellodendron amurense,Juglans mandshurica,Fraxinus mandshurica,Ulmus spp. and Fraxinus rhynchophy which located in 125.9°E～129.1°E had middle class of drought tolerance,so that they had the highest average fractal dimension and the most complex spatial distribution than the species of drought tolerance and drought intolerance.

Since May 1998, we had made the assorted technique studies on raising the effect of Casuarina equisetifolia afforestation on the frontal dry sandy land in the draught of C.equistifolia backbone forest strips on Chihu Forest Farm, Hui\'an County and Chishan Forest Farm, Dongshan County both in Fujian Province. Through the experimental studies for about two years, on the basis of analysing the main reasons for the afforestation failure on difficult sites in the draught, the preserving rate of C.equisetifolia afforestation on the sandy land in the draught was raised to 80%～90% by means of selecting the resistant C.equisetifolia strains for application, determining the afforestation models in line with local conditions and adopting the drought-resistant afforestation assorted techniques, including digging deeply for site preparation, putting into the earth removed from other places, mixing mud, making the afforestation season earlier, selecting largely rainy days for afforestation, planting deeply with big seedlings, etc., as well as adopting the combinative afforestation methods of ridging tending for preserving the soil moisture and watering for keeping seedlings in the drought season with the dampproof and windproof engineering measures of building sandy dikes and setting up windbreaks. The important breakthrough has been obtained in the respect of afforestation techniques, which provides the useful experience for the national special protective forest strip engineering construction on difficult sites in the draught in coastal zones.

The distributions of biomass and nutrients in different rotation plantations of Chinese fir are studied by the investigation of different aged plantations in the central productive area of Chinese fir. The results are as follows: There are significant differences among Chinese fir plantations of different rotations concerned with stand biomass(SB) and nutrients distribution. The ratios of branch/SB, leaves/SB, root/SB, sapwood/SB, canopy/SB, sapwood/heartwood and canopy/stem decrease gradually and the ratios of stem/SB, bark/SB and heartwood/SB increase as the age increases. The shorter rotation is, the more nutrients are taken away per unit biomass by harvesting and the more nutrient of soil is consumed. Moreover, short rotation results in increase of soil disturbing frequency by cutting, control burning and site preparation and inhibition of its underground vegetation development. Therefore, rotation is an important factor influencing the site productivity of Chinese fir plantation. The ecological mature age of Chinese fir must be taken into consideration in the future and rotation should be prolonged in order to offer plantation a period for site nutrient recovery and buffer the pressure on the site by plantation management.

Based on specimen correlation matrix, the main economic character of 9 varieties of apricot for using nucleolus were determined by pincipal component analysis,which included fruit yield per tree,weight per fruit,flesh rate,stone rate,kernel rate,dry stone weight,dry kernel weignt,kernel yield per tree,and amount of stone to produce one kilogram kernel.According to more than 85% of the cumulative variance proportion,the results proposed two principal components and its function equations which reflected the main economic characters of apricot for using nucleolus.The key principal component values of various varietics were calculated,it will be applied to selecting fine varieties,the results were similar to practical phenotype.The method of principal component analysis was more scientific and simple than the method of qiving a mark of main economic characters while evaluating main economic characters of apricot using for nucleolus copmprehensively.It will provide a theoretical basis for selecting fine varieties of apricot using for nucleolus.

Sixty-one bamboo species belonging to twenty-three genera in Yunnan which had been in flowering and fruit bearing in past fifteen years were recorded in this paper.The study shows for the first time that the flowering and fruit bearing phenomena of bamboos closely relate to their living states,wild or cultivated,and also are connected with their taxonomical position in genus level.The main points are as follows.(1)Around 88% wild bamboo species are in the type of flowering wholly.On the contrary,64% cultivated bamboo species are in the type of flowering fragmentarily.(2)Furthermore,the most bamboo species in the genera of Melocalamus,Schizostachyum,Cephalostachyum, Gigantochloa,Indosasa,Ampelocalamus act.are in the type of flowering wholly,and the most bamboo species in the genera of Bambusa,Dedrocalamus,Neosinocalamus,Pseudostachyum act.are in the type of flowering fragmentarily.(3)The most species in the genera Melocalamus,Schizostachyum,Gigantochloa,Cephalostachyum,Ampelocalamus act.are dead after flowering.And those in Neomicrocalamus,Bambusa,Indosasa act.are deadless after flowering.(4)About 79% wild bamboo species could bear fruits after flowering,only 27% in cultivated species.It means that most wild bamboo species can reproduce naturally by seeds,and most cultivated bamboo species have lost their ability to multiply by sexsual reproduction.The authors here try to explain the flowering phenomena of bamboo in the viewpoint-Environment-Endopathic Presumpution.It is considered that bamboo will flower when they grow to physiological maturity.The evironmental factors could affect the course of bamboo flowering,such as advancing,delaying or terminating the flowering.The this kind of effect,however,can only occur in the period during which bamboo has almost developed to physiological maturity.

By the method of fixed plots,underground structure of mixed forest of Chinese fir and Phyllostachys heterocycla cv.pubescens,which was established in 1974 by planting the pure Chinese fir forests on felled bamboo forests,was investigated.The results showed that the growth of bamboo rhizomes was atimulated by Chinese fir trees and the proportion of healthy buds increased.When the density of Chinese fir was 900～1350 trees per hectare,the proportion of healthy rhizomes root was higher,and underground structure of bamboo was optimization.There were about 92.8 percent of healthy rhizomes in the depth of 0～40cm soil layer,over 60 percent of which distributed in the depth of 0～20cm soil layer.Chinese fir trees stimulated rhizomes growing deeper.With the increase of Chinese fir density,rhizomes number in the depth of 0～20cm soil layer decreased and which in both 20～40cm and over 40?cm soil layer increased obviously.

In the present study a three-generation Populus deltoides (R)×P.cathayana (S) hybrid poplar pedigree,comprising F₁ and F₂ progenies,was used to investigate the genetic control of resistance to Alternaria alternata (Ala).The susceptibility of parents,F₁ and F₂ to Ala was tested in both the greenhouse and the field.The results suggested that the resistance be determined by a single recessive gene for P.deltoides. To identify the markers linked to Ala resistance,using RAPD markers,in combination with bulked segregant analysis,we analyzed approximately 4200 selectively amplified DNA fragments using 400 primers and identified two markers linked to this resistance gene. Ala is mapped on group 3,and 3.60 cM from RPH12-6 or RPH12-4.The results are the basis for molecular marker assisted selection and early identification of disease resistance varieties.

The Pinus armandi blister rust and the aphid Pineus armandicola were usually occurred during the same period within the harmful bioecosystem of armand pine forest,and there was conplex relationship between them.So,if the unitary object control threshold was applied under this condition,the outcome would be biased,the danger that the loss ratio of the timber volume exceeded the economical injury level would be occurred. In order to avoid this case,the compound damage of both the disease and the pest was studied on No.220 Forest Farm,Dongchuan District of Kunming City,Yunnan Province.The result showed that the interrelationship of both the representative value of the damage grade of the Pinus armandi blister rust and that of the aphid Pineus armandicola with the loss ratio of the volume was evident,which could be expressed in a regression equation:Y=10.574+8.11324X₁+7.01964X₂ X₁ —the representative value of damage grade of Pinus armandi blister rust,X₂ —the representative value of damage grade of Pineus armandicola On the basis of the regression equation,and taking the differences of the timber volume,log price,control cost and control effect into account future,the compound control threshold dynamic model of both the disease and the pest can be formulated as:8.11324X₁+7.01964X₂=[C/(D×J×E) ]×100-10.574　 C—control cost,D—checked volueme,J—log price,E—control effect This model provides the theoretical basis for the integrated control of the diseses and pests of the armand pine.

The distribution of the cellulolytic enzymes namely Endo-β-1,4-glucanase (C_X),cellobiohydrolase (CBH) and β-1,4-glucosidase activities in gut and salivery glands of Apriona germari (Hope) was measured.97.13% C_X,95.7% β-1,4-glucosidase and 97.03% CBH activities were found in the midgut and not detected in salivary glands.This showed that the major origin of cellulases were endogeneous.

Apriona swainsoni(Hope), eating branch and stem of trees, is one of the most serious forest plant quarantine pests in China. Study results showed that once the larvae bored into xylem of trees, it was very difficult to control them by any preventive measure. So it is very important to forecast accurately ovipositing occurrence time of Apriona swainsoni (Hope). Based on the results observed and measured by feeding in condition of variable and constant temperature during 1997～1999,initial temperature for egg development(C), effective accumulated temperature(K) and theoretical equations (Y and N) were found and put forward. They were respectively C=12.29±3.10 or C=12.26±0.81 or C=12.02±1.57;K=164.63±32.12 or K=174.67±9.02 or K=175.52±16.30, Y=12.29±164.42X, r=0.9831>r_0.01=0.6055 or Y=12.26±174.67X, r=0.9910>r_0.01=0.6835 or Y=12.02±175.52X, r=0.9334>r_0.01=0.4487. Prediction formulation: N=164.42±32.12T-(12.29±3.10) or N=174.67±9.02T-(12.26±0.81) or N=175.52±16.30T-(12.02±1.57). It was more simple and practical to feed them in condition of variable temperature. It will be more rationalization and accuracy using the method of weighted variable temperature.

Observation and analysis were made on changes in morphology and physiology of seeds and seedlings of Ligustrum lucidum which were subjected to a simulated acid rain adjusted to different pH levels. The results showed that differences in germination rates were not statistically significant among the treatments, but pH2.0 and pH3.5 acid treatments were found to inhibit germination slightly. Under the exposure to pH2.0 treatment, seedling growth was severely retarded, due to the visible damage to foliage, decreased chlorophyll contents, elevated leaf cell permeability, and acidified leaf sap. While no significant morphological and physiological changes were observed, seedlings exhibited growth declines by pH3.5 treatment. Top growth was stimulated by pH5.0 acid treatment. No significant treatment effects were observed at pH 6.0.

The tree ring width, pH value, wood chemical composition and element contents of poplars selected from healthy and acid rain damaged forests were analysed to evaluate the possible impacts on wood properties. Acid rain affected tree growth slower, tree-ring width narrower, tree-ring width of diseased tree decreased 12.67%. The pH values did not significantly differ. Compared with healthy trees, the content of holocellulose in diseased tree decreased 3.45%, but pentosan and lignin contents in diseased trees were higher than in healthy trees. Extractive content between diseased trees and healthy trees showed significant difference. The contents of K, Na, Ca, Mg in diseased trees were lower, but the content of Cu and S in diseased trees were significantly higher. Soluble sugars content in diseased trees was higher than in healthy trees. The results showed that there were a lot of differences in wood chemical properties between diseased trees and healthy trees.

The results of x-ray wood density of Ginkgo showed that the wood density was fractal in inter ring, intra-ring and whole-disc. The fractal dimension of Ginkgo wood from Jiangsu Province was 1.4430, respectively. Fractal dimension was a very important quantity of wood properties, it has relation with the ring width and has little relation with the ring density. The application of fractal theory is at the beginning of going into the wood science. It will make a great development in the wood science in future.

About 30 years achievements of the studies on the regulation of flower sex differentiation ,decreasing empty bundle, raising the rates of fruit,green branch cutting and grafting surviving,regulating seed sprouting,improving the properties of storing etc.of Chinese chestnut are reviewed in view of the application of plant growth regulator and many chemicals related to nutrition physiology for regulating the substance metabolism and physiological function of Chinese chestnut growth process. Meanwhile, this paper also discusses on the research current situation and main research directions of chestnut chemical regulation in future.

Current studies on flavonids of Ginkgo biloba leaves have been reviewed. Flavonoids come from the derivatives of the products of shikimate pathway and acetate-malonate pathway. Flavonoids contents in Ginkgo biloba leaves are controlled by genes to a great extent. However, other factors also play important roles, including photosynthesis, season, year, tree age, leaf maturity, plant seed-load, the reproductive ways of nursery stock, the variety, time and quantity of the fertilizer application and so on. The influence of the ecological factors on flavonolds content mainly takes place at young stage of Ginkgo biloba trees. Among all ecological factors, light and temperature are the most important. Recent reports have showed that the significance of the principal ecological factors influencing flavonoids content is in the following order:latitude, annual precipitation, annual mean sunshine percentage, and annual mean temperature. Regulating enzymes in flavonoids biosynthesis include L-phenylalanine ammonia-lyase(PAL), chalcone synthase(CHS), chalcone isomerase(CHI), UDP\|3\|O\|glucosyltransferase(UFGT),4\|coumanate coa ligase(4CL) according to recent research reports. Regulating mechanism of PAL was relatively known best. Ethylene and abscisic acid enhance flavonoids biosynthesis, while gibberellic acid has opposite effect. The effects of the growth promoting hormones have exhibited inconsistency. It is said that the mechanisms of plant hormones are connected with the regulation of enzyme activities and maturing process. The great progress in producing flavonoids by means of biological technology and chemical synthesis has been made. The inconsistent relationship between leaf yield and flavonoids content has been observed. The methods of increasing flavonoid content in \%Ginkgo biloba\% leaf have been commented and their outlook has been analysed in this paper.

Based on coordinates differential modes, using Portable GPS Receiver by near-real time process, the positioning precision is about ±5 m. It can be used in forest to do many positioning. Position test to be done under crown measuring more than 4 satellites by synchronous measure, positioning precision is less than ±5 m. When measure time is more than 20 minutes. In addition, why differential-positioning precision is better has been analyzed.

Through experiment, the effective accumulated temperature and the threshold temperature for development of Chouioia cunea Yang (Hymenoptera:Eulophidae), a powerful pupa endoparasitoid of the intruded insect pest-fall webworm, Hyphantria cunea Drury (Lepidoptera:Arctiidae), are 365.12 degree-day and 6.14℃, respectively. Meanwhile, the curve diagram of functional relationship between theoretical development duration and temperature is given. These data are important in mass-rearing the wasp for biological control of the pest.