Dynamics of a degraded Karst forest in the process of natural restoration,Maolan National Reserve in Guizhou province was studied.The structure of adaptive grade species groups was taken to indicated the change of species composition.The dominator in succession stages was pioneer species in herbaceous and herbaceous scrub stages,sub pioneer species and transition species in scrub shrub and shrub tree stages,sub climax species and climax species in evergreen and deciduous broad leaved forest,and climax stages.The pattern of species group replacement was that dominance of species groups to be transferred from pioneer species to transition species up to climax species.With natural restoration of degraded karst forest,community height,coverage,dominance were raised gradually,and their range were 0.6～16.9m,0.29～0.79,0.8720～21.8981 cm²·m^-2,respectively.Density was increased in early stages,then decreased.Species number(S),Shannon Wiener index(H '),evenness(J)were increased but ecological dominance(C)was decreased,and their values were 16～50,0.99～4.72,0.77～0.83,0.16～0.05,respectively.Community biomass accumulated gradually from 3.49 t·hm^-2 to 87.45 t·hm^-2 .Percentage of seedlings in total trees increased,and community regeneration strategy was that asexual regeneration in early stages changed into seedling regeneration in later stages.

Based on the investigation of 33 plots in Anhui Province,the effect of soil-forming rock on macro-element and micro-element contents in the bark of wingceltis,the effect of soil pH values on the mineral element contents in the bark of wingceltis and the relationship between the mineral element contents in aboveground biomass components were studied.The results indicated that the highest N and P contents in the bark of wingceltis were achieved in the stand growing on the soil from sandstone,and the highest K content in the bark occurred in the stand growing on the soil from limestone.However,the N,P and K contents in the bark for different sprout age were in the order of age 1>age 2>age 3.Compared with other soil-forming rock,the Ca and Mg contents in the bark which grew on the soil from limestone were the highest,especially the Ca content reaching 17.3g·kg^-1,which was 1.48 and 1.68 times of the soils from phyllite and slate respectively.With the increasing of sprout age,the Ca content in the bark increased,and the Ca content in the bark with 3-year-old sprout was 2 times of 1-year-old sprout.The highest Cu and Zn contents in the bark were also achieved in the stand growing on the soil from limestone,but the highest Mo and B contents in the bark took place in the stand growing on the soil from slate and the Mn content in the bark was the greatest in the stand growing on the soil from phyllite.Soil pH values have a remarkable impact on the mineral element contents in the bark of wingceltis.The Ca,Mg,B and Cu contents in the bark were in the order of alkaline soil(pH7.5～8.5)>neutral soil(pH6.5～7.5)>acid soil(pH5.5～6.5),Mo and Zn contents in the bark were neutral soil>alkaline soil>acid soil,and Mn content in the bark was acid soil>neutral soil>alkaline soil.The relationships between the mineral element contents in aboveground biomass components were complicated,however the Ca and Mg contents in the bark were highly correlated with the contents in the xylem.

Plant functional types can be defined as sets of plants exhibiting similar responses to environmental variations and having similar effects on the dominant processes in ecosystems. In the present paper, 23 plant functional types were identified from five zonal woody plant communities occurred in Gansu province, NW of China. This paper has made some explorations on the relationship between the patterns of zonal woody plant functional types and the hydrothermic factors to which they subjected. Some conclusions are as follows: Environments with warm humid combinations would result in well developed plant communities characterized by arbor, big shrubs, lianas and parasites as the dominant life forms and key fruit, nut, drupe, follicle, caryopsis as the dominant fruit types, while dry cold habitats are always correspond to those with shrubs, small shrubs and deciduous trees as well as capsule as the dominant life forms and fruit types. The trade off of species relative richness between dry fruit and sarcocarp in a given plant community may be strongly influenced by the humidity level in plant's growing seasons. In addition, plants of cone fruit types are specially favored by wet cold habitats. A precipitation gradient is one of the decisive factors shaping the patterns of both species richness and richness of plant function types (in terms of plant stature and fruit types) among these five zonal woody plant communities in the study area, while environments with optimal hydrothermic combinations would lead to the highest diversity of fruits types.

In this paper, the Wangqing Forestry Bureau was taken as a case of overcutting forestry area in northeast China. Not only the influence of the classified management and proportion of special public area on forest resources and industrial structure were simulated ,but also the sensibility analyses of proportion of selective area and proportion of special public area we carried out and the desirable project of structure regulation was given. Results are as followed: by now, wood logging & transportation still has been the dominant industry of Wangqing Forestry Bureau. It is helpful to increase forest growing by implementing classified management and improving proportion of special public area.

This paper dealt with callus induction from different Paulownia plant leaves and their plantlet regenerations. The results indicated that MS meidium was optimum one for induction of callus from 5 species of Paulownia plant leaves; that induction media from plant leaves of Paulownia tomentosa, P. australis, P. fortunei, P. elongata and P. tmentosa×P. fortunei were MS+0.5NAA+4BA、MS+0.3NAA+2BA、MS+0.5NAA+4BA、MS+0.3NAA+6BA and MS+0.3NAA+8BA; that bud induction ones from those plant leaf calli were MS+0.3NAA+12BA, MS+0.3NAA+12BA, MS+0.5NAA+12BA, MS+0.5NAA+12BA, MS+0.7NAA+12BA;and that 1/2MS+0.1NAA, 1/2MS+0.1NAA, 1/2MS, 1/2MS+0.3NAA and 1/2MS+0.5NAA were those rooting media.

The poplar(.Populus tomentosa Carr.) shading on farm field, with shading index and shading degree, was reported under poplar crop intercropping system in Northern China farm region. The results demonstrate that poplar young growth (spacing 3 m×2 m×18 m) brought on shading index 1.3%～67.8% and shading degree 0.3%～16.5% on farm field when stand ages were 1～7 years, and near and mature stand (spacing 4 m×30 m) resulted in shading index 51.3%～76.0% and shading degree 22.8%～28.1% when stand 10～14 years as well. But using shading degree to express shading on farm field is better than shading index, and shading degree 15% is suggested the maximum shading degree that could be accepted in farm field.

Sophora japonica L. Seedlings were grown under atmospheric CO₂ enrichment levels of 600、800、1000、1500 and 2000?μmol·mol^-1 within film greenhouse with monitorring CO₂ concentration by BEM 1 system for 3～5 hours every day and lasted 80 days CO₂ enrichment promoted significantly seedling growth,1500?μmol·mol ^-1 CO₂2 level was proved to be best one among 5 CO₂ enrichment levels,with 41.45%、 44.95% and 160% increase of dry weight、starch content and photosynthetic rate respectively. stomatal resistances of seedlings grown under high CO₂ enrichment levels were higher than the control,which was benefical to improve water use efficiency(WUE),total amino acid contents was lower,which increased C/N of seedlings,microstructure of chloroplast shown that starch acclimation of the seedlings grown under high CO₂ level reduced grana formation,which may result in down regulation on photosynthesis,thus,1000～1500?μmol·mol^-1 CO₂ enrichment level with N fertilizer was recommended to Sophora japonica L. seedling cultivation

This paper was based on the study of the physiological and ecological characters of main species within family of Ulmaceae, and the analysis of the soil type and climatic conditions in Mt. Lanya. The suitability of tree species there were also studied. The results showed that Pteroceltis tatarinowii, Zelkova schneideriana, Ulmus chenmoui, U.gaussenii, etc. in family Ulmaceae were the best species for limestone mountains in the eastern of Anhui Prvovince, because their physiological characters and succession suitability are adaptable to the high calcium and lacking water habitat.

Response of dominant tree seedlings from secondary successional forests to gradients of pH value,moisture,nutrients and light was studied in order to further test the adaptability of dominant tree seedlings to the environment in the south subtropical zone,Guangdong Province,China.These species were Pinus massoniana (pioneer species),Schima superba and Castanopsis fissa (transitional species),Cryptocarya concinna (late-successional species).The techniques to determine the response of these species seedlings to the gradients of the environment were ecophysiological technique by combining niche breadth,niche overlap and deviation from the central value of the niche.The data were the rate of net photosynthesis and the export and distribution of photosynthetic product determined by ¹⁴C-glucose treatment.The pioneer seedlings exhibited the highest rate of net photosynthesis and export and distribution of photosynthetic product to growth bud in the high light,also exhibited the largest niche breadth and deviation value at the soil moisture gradient,the late successional species seedlings was contrary.These values in the pioneer seedlings decreased when seedlings were transferred to low light condition for l year,and the seedlings of both transitional and late-successional species had the highest rate of these in the forest gap habitats,no in some shade habitats. Because of the development of root system,the transitional tree seedlings showed the largest niche breadth and deviation value at the nutrient and pH value gradient,and pioneer seedlings were contrary at nutrient gradient,late-successional seedlings were contrary.Finally,the value of the niche overlap of these seedlings showed that strong competition among tree species in the successional forest communities.

Based on the data about Pinus taiwanensis population and the theory of survival analysis and spectral analysis,the static life table,the curves of survival,mortality rate,killing power and hazard rate are drown in this paper.At the same time,the authors analyzed the population dynamics by spectral analysis method.The results showed that the curve of survival generally trend to the DeeveyⅡ—Ⅲ,and there was two peaks of mortality.Their death intensity and the time when they have mortality peaks had significant difference in different areas.The results from spectral analysis showed that Pinus taiwanensis in different areas had different growth periods,too.All these were related to the difference of geographical environment,climate and so on.

Shortage of large timber of Popular has seriously restricted the sustainable development of plywood and its relative industry. By ten years' research on how to utilize the abundant resources of flood land in Southeast Coast to build large area bases of large timber of poplar, some key techniques were proposed, such as introduction to new clones, main site restriction factors, density and technical maturation period of stands, compound rotation management, control of nodal scar, determination rational rotation and optimization of culture pattern, which would provide scientific basis for building large area bases of fine large timber of poplar.

The choice behaviors of Oligonychus ununguis to host plants and Amblyseius finlandicus were determined with a Y-tube olfactometer. Result showed that the spruce spider mites were attracted by the odors from the leaves of Quercus acutissima Carr.,Quercus variabilis Bl.,Castanea mollissima BL. and Quercus dentata Thunb. uninfested by Oligonychus ununguis. But the odors from the leaves of Q.dentata were less attactive to the spider mites than those from Q.acutissima,Q.variabilis and C.mollissima. The needle leaves odors of Pinus tabulaeformis Caff. and Picea koraiensis Nakai were repulsive to the spider mites. When the uninfested leaves and infested leaves with O. ununguis of the same host plant were compared in the olfactometer, the spider mites showed an obvious preference to odors released from the infestd leaves. The spider mites showed a greater preference to the infested leaves with spider mites and their products than to the infested leaves from which all the spider mites and their products had been removed. The host plants infested or not, the infested host plants with spider mites or without had significant influence on the taxis of A.finlandicus. A. finlandicus could be attracted by the odors from uninjured leaves and injured leaves by O.ununguis. But it showed a greater preference to the latter than to the former. There was a significant difference between the response of A.finlandicus to the infested leaves with spider mites and their products and to the infested leaves without spider mites or their products.

Pineus armandicola Zhang is an important defoliator of armand pine(Pinus armandi). The study of the biology of the pest was carried out systematically in the No.222 Forest Farm, Dongchuan District of Kunming, Yunnan Province. The alternate host —likiang spruce and the sexual generation of the pest were found for the first time. That shows Pineus armandicola has a complete life cycle. It lives and attacks on both armand pine and likiang spruce, and its sexual generation takes place on the first host. The morphs on likiang spruce are sexules, fundatrices(overwintering by second or third instar nymphs in the leaf sheaths of likiang spruce) and gallicolae in proper order. Finally the alate gallicolae fly to armand pine and produces sistens, and overwinter by nymphs in the leaf sheaths and bark crevices of armand pine. Independently, the pest can also finish its incomplete life history on armand pine as alienicola, which can at most have six generations per year through female parthenogensis in Dongchuan district. The phenomenon of generation overlapping is common.

The spatial and temporal dynamics and statistical distribution of forest fires in Heilongjiang province was studied here based on fire data of the province during 1980～1999 by means of GIS software. The results showed that the 20 years fire history can be divided into two phases: low fire occurrence stage before 1987 and high fire occurrence stage after 1987 The annual fire number and anthropogenic fire number are positively correlated with similar spectrum cycles of 2.3, 4.6 and 16 years and a size spectrum cycle of 6 years. Annual areas burned by lightning caused fires is irrelevant to its number, the former cycles every 9.1 years and the later every 9.1 and 3.0 years in each spectrum. Fires occur mainly in April and May with more burned areas in March and April for anthropogenic fires and May for lightning caused ones. The fires spatially distributed as a belt from northwest to southeast with 5 high fire occurrence regions and few burns in the west, southwest and northeast parts of the province. The fire size, averaged area expanding rate and burning time follow lognormal distribution with a self organizing character with respective fractal dimensions of 0.86、1.045 and 0.68 Discussion is made on fire cycles, self organizing characters and suitable frequency and intensity of human introduced fires in ecosystems. It is emphasized that although self organizing function links the spatial characters of fire with temporal ones, a lower limit exits when describing self organizing character with negative power functions and a formula for calculating the limit is presented here. Comparison is also made between fire fractals of different regions.

Variation in growth ring width,wood basic density and hot extracts content of rubbertree were reported in this paper and its wood improvement and processing utilization of its wood resources were also discussed.The significant difference in wood basic density was found between the individuals within clones(DF95,PR107 and PRIM600),but not found among clones.Wood basic density in radial direction within trees of PR107 first increased gradually,levelled off after the 6～7th growth ring and decreased a little within over matured wood near bark.Wood basic density in longitudinal direction within trees augmented from base to top until its maximum,then reduced.Variant range of wood basic density within trees varied from 0.470 g·cm^-3 to 0.650 g·cm^-1,its variant coefficient was within range of 3.0% to 8.2%. Variant range of wood basic density between trees varied from 0.421 g·cm^-1 to 0.580 g·cm^-3 and its variant coefficient was within range of 5.16% to 7.05%.The hot extracted content of rubberwood was high compared to the others hardwoods and it varied from 6.65% to 11.53% within trees and among trees.The positive correlation equations of extracted wood density with unextracted wood density of three clones of rubbertree were significant at 0.01 level or 0.001 level.Relationship models of growth ring width and wood basic density of rubbertree clones with the tree age were expressed with equations of 5～6 times multinomial.Their relationship coefficients were from 0.8362 to 0.9787.

The cambium of Populus tomentosa Carr. trees planted in Beijing have entered resuming phase before bud swelling. However, initiation of cambial activity with cell proliferation and increase in immature phloem cells was about a week later than bud sprouting. In active phase, phloem differentiation got rapid before mid-April and then continued up to early September with a slow speed. On the contrary, the xylem production commenced in late April (three weeks after appearance of immature phloem cells) and increased fleetly during June before declining in August. Meanwhile, the appearance of mature xylem cells was about a month later than that of mature phloem cells. Different from results of other researches, the cell number of immature and mature xylem of Populus tomentosa Carr. increased rapidly between late April to late June as cambium and immature phloem declined. The cambial tissue entered dormant phase from late September and remained till the following spring. After electrophoresis, there were totally eight peroxidase isozyme bands in dormant cambial region. The number and deepness of bands in zymogram during cambial activity phase were lower than that in other phases. Especially, POI₁, POI₂, POII₁ and POII₂ in peroxidase isozyme bands probably had a mutual relation with activity of cambial cell and differentiation of xylem. The result of histochemical reaction also showed that distribution and activity of peroxidase in different type of tissues or cells had significant difference. These indicated that peroxidase isozyme in cambial region was related to the level of endogenous IAA and differentiation of vascular tissues.

Based on the data observed continuously in fixed positions, various benefit losses resulted from cutting the Chinese fir plantation were analized by isobenefit correlation substitution method. The Chinese fir plantation was located in Huitong County, Hunan Province. The results showed that compared with forest area, the amoun t of water storage in cutover area decreased 646 m³·hm^-2 The capacity of regulating flood in cutover area was 786 m³·hm^-2 less than that in forest area. The amount of water supply during water exhaustion in cutover area was 318m³·hm^-2 less than that in forest area. The amount of mud and sand losed every year in cutover area was 48t·hm^-2 more than that in forest area, which resulted in more nutrient substance losed from the cutover area each year, e.g. N 0.087 t·hm^-2, P 0.047t·hm², K 0.101 t·hm^-2. According to the relative calculation the annual benefit loss of water resource containment would be 849 yuan if one hectare of cut Chinese fir plantation which was cut, that of soil fixation and fertility would be 504 yuan, that of soil improvement 102 yuan, totally 1455 yuan. The reliable scientific basis was provided for rational utilization of forest resources and the evaluation of loss after cutting forest.

Modern wood transportation planning requires not only a lot of numeric data but also spatial data. GIS-based Decision Support System for Wood Transportation Planning (GDSSPP) was combined with linear programming (LP) method utilizing GIS-based techniques. The combined costs of road and off road transport was taken as the objective function to find the least cost route and the optimal landing locations of wood transportation. The transport costs and allowable wood volume of stands were calculated. An LP model was developed to allocate timber resources among mills in order to minimize the wood transport costs from harvesting sites to mills. The parameters of the LP model, including the transport costs, allowable wood volume and wood orders, were written into a text file in MPS format which were then accessed by solver LINDO to solve the LP problem. The system is an effective tool for forest managers to complete wood tactical planning in wood procurement. Basic information for operative planning is also supplied by the system.

In this paper, the five main factors, site index, stand age, stand density, habitat type, and stand structure, markedly influencing stand growth and yield, were described, specially about habitat type and stand structure. Some representative model systems of stand growth and yield prediction were introduced, classified as the three model systems, e.g. whole stand model systems, stand class model systems, and individual tree model systems. Some typical growth and mortality models were also introduced. Tree and stand are two different level ecosystems. Based on ecosystem attributes, such as integrality and simultaneous feature of systems, intercross correlation among components, and so on, systematizing models were proposed. The reality and precsion of stand growth and yield prediction models will be improved by establishing simultaneous equation system and by fitting its regression parameters with three-stage least-squares method.

De-farming and reafforestation is a complex socioeconomic systems engineering, which involve provisions, technology, financing and labor force. Based on the review and analysis of necessity and contradiction, de-farming and reafforestation policy efficiency was construced. According to the result, this article pointed out that problems such as too much economic forest, too much government administration and singularity of vegetation species, and some suggests were given. At last, the article considered that consummate of the eco-environmental compensation system is the key of sustainable implement.

We used a experimental procedure of wood drying to show the nature of the pore space in wood. Cubic blocks of Ginkgo biloba and Castanea mollissima wood were executed, and posting them in oven, the temperature was increased after 4 hours and measured the mass changes of weight and volume at the same time, the plots of the mass versus block edge sizes are straight lines whose slopes correspond to the fractal dimensions of the void volume in the wood. Results for different species and for distinct temperature are shown. Suggesting the fractal dimension as a new relvant to parameter to characterize the porosity of wood.

Through field investigation and observation in the arboretum of Jianfengling of Hainan island,the major tropical trees in the arboretum were preliminarily assessed into the different types of architectural models.Some tropical tree species were determined as certain types of the architectural models,and some were listed in the possible architectural models.Further research and observations are needed in order to determine the precise architectural models to which the tree species belong.

By using the modified method of growth increment, in this article the competitive increment models of individual tree for Chinese fir have been developed, the estimate models of diameter growth percentage for Chinese fir have been obtained in Huitong, Human. On the basis of the relationship between height, volume and diameter, the models of height and volume growth percentage were derived.

Fourteen 10 mer primers were used for RAPD (Random amplified polymorphic DNA) analysis across a fullsib family, including 2 parents and 18 sibs, of Liriodendron chinense×L. Tulipifera. Of the total 57 fragments amplified, 20 (35.09%) were polymorphic between the 2 parents and 28 (49.12%) segregants in the sibs, indicting a little lower of polymorphism and heterozygosity at RAPD loci in the 2 species, compared with other tree species studied. Of the 20 polymorphic loci, 4 (appeared in the male parent) did not segregate in the progeny, indicating the genotype in these loci were AA (α=0.5¹⁸), so, may be used as paternal markers for paternal identification. Fourteen parental polymorphic loci (24.56%) segregated 1∶1 in the progeny as expected, and 12 parental monomorphic loci (21.05%) segregated 3∶1 as expected, showing a Mendelian dominant inheritance fashion for an allele. Two parental monomorphic loci (3.51%) were detected to segregate in aberration from the expected ratios (3∶1).

RAPD technique was used to detect the genetic relationship among seven Betula species.233 loci in total were amplified by using 14 random primers.The percentage of polymorphic loci varied from 12.02% to 36.91%,in which B.costata had the highest variation level.The dendrogram of genetic relationship was constructed on the basis of the genetic distances among species.According to genetic distance in more than 1.22,six species were clustered into two groups,where B.fruticosal was one group and others,including B.davurica,B.pendula,B.platyphylla,B.schmidtii and B.costata, were grouped together.It indicated that the result of genetic relationship obtained by RAPD technique was closely consistent with that classified by traditional morphological classification.The analysis of genetic relationship among Betula species would validly guide the parental selection and interspecies crossing for Betula species.

The bark beetle, Dendroctonus valens LeConte, infested mainly pine tree over 30-year-old. It has been a disaster of pine forest in Shanxi province and part areas of Hebei and Henan provinces since 1998. This research reported the results of infectivity of 7 species belonged to Steinernema and Heterorhabditis to matural larvae of the bark beetle Dendroctonus valens LeConte in laboratory. Steinernema ceratophorum, isolated from Jilin province in Northeast China, was the best nematode species for infection of the pest larvae among the 7 species of nematodes. The mortality of insect larvae reached to 90% after exposure to nematode for 96 hours. The LC₅₀ based on 3 day insect mortality was 24±4.2 infective juveniles. Other nematode species tested in this trial were not sensitive to the larvae of Dendroctonus valens. Each host cadaver could produce 6770 infective juveniles. These new generation nematodes would provide nematode resource to infect healthy insect larvae living in bark during field application. This result would be helpful for finding a new way to the integrated control of the bark beetle Dendroctonus valens.

The results showed that the contents of free serine、glutamate、proline、alanine、cystine、valine、isoleucine and total amino acid in the resistant varieties after inoculation during incubation period gradually decreased and reached the lowest point at 168 h after inoculation,the contents of the free aspartate、threonine、serine、glycine、alanine、cystine、valine、isoleucine、leucine、phenylalanine and total amino acid in the middle resistant varieties gradually decreased and reached the lowest point at 168 h,the content of free glutamate in the middle susceptible varieties after inoculation during incubation period gradually increased and reached the highest point at 168 h,other kinds of amino acid in the middle susceptible varieties didn′t show regular changes,the content of free proline in the susceptible varieties after inoculation during incubation period gradually increased and the other kinds of amino acid didn′t show regular changes.Before inoculation the contents of total free amino acid in different resistant varieties didn′t show regular changes,but those of free alanine and cystine were positively relative to the susceptibility of the host,and that of the free phenylalanine were positively relative to the resistance of the variety.At 168h after inoculation the contents of free proline\,glutamate\,serine\,glycine\,alanine and cystine were negatively relative to the resistance of variety.

Two Populus deltoides clones (P.deltoides Bartr.cl.‘55/65’and P.deltoides Bartr.cl.‘2KEN8’)with high resistance to Anoplophora glabripennis (Resistant rate are 96.16%,97.37%,respectively) were used as parents and crossed by artificial controlled pollination,37 among of which F₁ progenies were planted in Shuyang,Jiangsu province and tested for insect resistance with the borer Apriona germari Hope.Under artificial inoculation and natural infestation with Apriona germari Hope,significant variations of oviposition and larval development were observed between progenies.Both artificial inoculation and natural infestation alow the characterization of plant resistance to insect,although insect behavioral responses sometimes differ between free choice (natural infestation) and no choice experiment (inoculation).

Using shock tube and coherent experimental technique, the sweeping process of shock wave in ground, forest belt and flame field is photographed, the sudden extinguish time of flame and the overpressure of shock wave was measured. The research showed that it was obvious for shock wave extinguishing forest fire, the high dynamic pressure induced by shock wave may be the immediate cause of extinguishing flame. Moreover the overpressure, negative pressure and temperature rise of air causing by shock wave would make the combustible pyrolysis gas of forest tree mix with atmosphere then ignite and burn out, which probably is an important effect in restraining forest fire.

In this paper, we have compared veins and stomates in the leaves of Calamus egregius, C.simplicifolius, C.tetradactylus, C.dioicus, Daemonorops margaritae and D.jenkinsiana. Still farther with the E.M., we have observed the ultrastructure of seedlings and culture seedlings of C.simplicifolius, C.tetradactylus and Daemonorops margaritae. We aim at distinguishing rattanc and improving the cultural technique.