The influence of canopy on the rainfall size distribution and on the raindrop kinetic energy was researched quantitatively and on the basis of effect mechanism for the tree species of Mao-bamboo (Phyllostachys pubescens),Chinese fir (Cunninghamia lanceolata),Black locust (Robinia pseudoacacia).Such research is the basis for further researches on the benefits of forest in terms of hydrology and soil protection.The study showed,that the raindrop size (D,raindrop diameter,mm) distribution is basically not influenced by the type and intensity of rainfall in open field,i.e.it is fairly stable.When the raindrop size distribution of canopy rainfall is expressed with the equation of F=1-exp(-(10D/α)n),the value of parameter α is 2.7718、2.5939、2.5112 and parameter n is 1.7593、1.9175、2.6126 for Mao-bamboo,Chinese fir,Black locust respectively.The raindrop kinetic energy per unit canopy rainfall is also basically not influenced by the type and intensity of rainfall outside of forest.When the falling height of raindrop (H,m) is big enough so that all raindrops can fall with their terminal velocity,the potential kinetic energy of raindrop per unit canopy rainfall is 24.163J·m^-2mm^-1,23.214J·m^-2mm^-1,23.713J·m^-2mm^-1for Mao-bamboo,Chinese fir,Black locust respectively.The difference among the 3 tree species is small.In this study the models to calculate the raindrop kinetic energy per unit canopy rainfall according to the falling height were established,they are e_c=24.129[1-exp(0.0023H²-0.3259H)],e_c=23.214[1-exp(0.0025H²-0.3409H)],e_c=23.713[1-exp(0.0015H²-0.3467H)] for Mao-bamboo,Chinese fir,Black locust respectively.The raindrop kinetic energy per unit canopy rainfall decreases with falling height markedly in the range of 0～5m;relative markedly in the range of 5～10m,and no more obviously in the range of above 10m.The relations between raindrop kinetic energy per unit rainfall in open field and the rainfall intensity for different rainfall types were researched.The method to evaluate the influence of forest canopy on the rainfall kinetic energy and the possible approach to do such evaluation in a regional scale were also discussed.

The concentration,storage and allocation of nutrient element in Picea balfouriana plantation in west Sichuan forest region were investigated using field investigation, sample tree and plot harvest.The results show that,the total nutrient element storage of plant subventride in system were 1229.502kg·hm^-2,the storage in the tree layer was the largest,and constituted 77.22%.the sequence in which storage element varied among different layer was as follows:litter layer (205.872kg·hm^-2,16.73%),shrub layer (42.856kg·hm^-2,3.4%),herb layer (15.951kg·hm^-2,1.30%),bryophyte layer (15.361kg·hm^-2,1.25%),respectively.The total nutrient element storage in plantation ecosystem including N\,P\,K\,Ca and Mg,amout to 211696.097kg·hm^-2,in which storage in soil subventricle amount to 210493.2kg·hm^-2,and constituted 99.432%,the other in plant subventricle amount to 1202.892kg·hm^-2,and consitituted 0.568%.After analysing the nutrient situation in soil of the slash,the plantation and the virgin forest,it is put forward that the element storage in soil could meet the needs of normal growth of the plantation, and that the high density of the plantation was one of the main factors causing the decline of the tree growth after the stands 26-year-old.

Using ultrathin section and transmission electron microscopy,the developmental process of oil and mucilage cells in Cinnamomum longepaniculatum was observed.According to the development of three wall layers,the process can be divided into 4 stages.In stage 1,the cell wall is consist only of primary (the out) cellulose layer.This stage can also be divided into two periods:one of which is oil cell initial and another is vacuolizing oil cell.During this stage,there are some small electron translucent vesicles and quite different size dark osmiophilic drops in different shaped plastids.Similarly,there also exist dark and gray osmiophilic materials in ground cytoplasm,and their coalescence with vacuoles was observed too.In stage 2,suberized layer is present,and the lamellated suberin layer accumulates inside the primary cellulose layer.In stage 3,the inner cellulose wall layer is formed.Thicker and looser inner cellulose wall layer is piled up gradually inside the suberin layer.In this stage,because of the accumulation of a great quantity of osmiophilic material,the big vacuole becomes into an oil sac filled with osmiophilic lipophilic substances.In stage 4,oil cell matures and the cytoplasm disintegrates.After oil cell maturity,the ground cytoplasm starts to disintegrate,and becomes more electron opaque or exhibits a disordered state.Oil sac is enveloped by plasmalemma and attached to the cupule,which is formed by the protuberance of inner cellulose wall layer into the lumen.Mucilage cells come from parts of oil cells.There are two developmental patterns.One is that mucilage cell comes from oil cell whose inner cellulose layer has already formed.In the ground cytoplasm of such an oil cell,some multimembrane structures whose membrane arranged like concentric circles or like a spiral come out gradually and fill up the whole lumen.Finally,the multimembrane structures disintegrate and become into filiform or granular mucilage.Another pattern is that mucilage cell comes from fully matured oil cell,whose cytoplasm has already disintegrated.In such an oil sac,osmiophilic oil shows an inhomogeneous state.Many local disintegrative sites take place in the different electronic density oil,and these sites expand gradually.Finally,oil disintegrated completely into filiform or granular mucilage.This studies on the developmental ultrastructure of oil and mucilage cells verified that mucilage cell comes from oil cell.

Based on the investigation data from the sample plots of Eucalyptus spp.,Cunninghamia lanceolata, Pinus massoniana, Larix spp. and Pinus sylvestris var. Mongolica etc, and combining with other results of research projects on plantation, main natural factors and social factors which effect the productivity of Chinese plantation were studied systematically. The results showed: (1) The plantation productivity of the collective owned stand in the south of China was only 44.6% of that of state owned plantation, and whice contributed a 28% reduction in the plantation productivity in whole China. (2) The problem of unmatching species with the site was less serious than that people think of it usually in China, and it contributes only about 5% reduction in the productivity of Chinese forest plantation. (3) The low silviculture techniques were not the key facts that made the low productivity result of Chinese forest plantation. In fact, it was the product and incarnation of the economic development level of China in past decades as a result of interacting between natural factors, social factors and economic law.

The length,width,shell thinckness and percentage of kernel of Ginkgo fruit-stone collected from more than 200 mother trees located whole-wide range were measured.The results showed that all of the characters,except for single fruit-stone weight,no significant differences among the climatic zones were observed,but the differences among populations (or locations) within a climatic zone and individuals within population were very significant.The variation coefficients for each of four characters varied from 3.0% for kernel rate to 21.3% for single pit weight.These data indicated that the genetic improvement of Ginkgo through individual selection within population should be more effective than among populations,and much than among the climatic zones.Because the adaptability is one of the most important traits for inten sive cultivation,the genetic improvement efforts should be within each climatic zone and do not carry out throughout whole range.

Based on the data determined for 8 years from a Liriodendron chinense provenance trial located at Shaowu city of Fujian Province including 15 seed sources representing the natural range of the species was used to study firstly genetic variation between provenances and geographic differentiation pattern for main economic traits such as mortality,stem forking by branch formed, growth,stem form and wood basic density.The results indicated that there were great provenance effects for most traits.A classical clinal variation pattern for main economic traits beside wood basic density was not found because of effects of habitat fragmentation on genetic structure of the population (small population effect and isolation by distance effect,etc.).The range of the species in China can be divided roughly into two provenance regions and four sub-regions by cluster analysis.Superior provenances could be selected and recommended for pulpwood slash and plywood respectively.Marked sensitivity to site condition was observed,there were significant interactions between provenance and site environment,which must be considered in commercial plantation development.

After Long years sited experiment,recovery and reconstruction system of close,improvement and solid collocation are put forward against the worsen degradation.The experiment show that after 3～5 years of close,the main community biomass of S.bungeana and T.mongolicus increased 5.1～7.5 times than that of the unclosed,after reasonable close duration of S.grandis,i.e.,5 years,the biomass increased by 1.5～5.0 times.The fitted combinations of improved grassland in barren hill by bunch planting are S.bungeana+forb,L.davurica+S.bungeana,biomass increased 6.1～6.4 times than than of the unimproved.Ditch planting in wasteland of S.bungeana+A.frigida, S.bungeana+O.viciaefolia,S.bungeana+L.davurica,its biomass increased 4.6～4.8 times than that of the implanted.Ploughed planting of every two strip in barren hills are A.splendens,S.bungeana+M.sativa,S.bungeana+E.sibiricus+L.davurica,the biomass increased 4.5～6.5times than that of the implanted.Shrub-grass solid collocation,which are Caragana korshinskii+A.splendens+H.hamnoicle+M.suaveolens and P.davidiana+A.splendens,have formed stable renewable communities.The experiment,demonstration and popularization provide the quick recovery of shrub-grass in semi-arid region of Loess Plateau with scientific foundation.

The experimental results showed that the bead tree (Melia azedarach.) had strong alluring ability to the adult of the long-horned beetle Anoplophora chinensis.The alluring distance was over 200m,and the number of the beetle allured in June and July accounted for 71.6% in the whole alluring period,the time for the beetle to take food,have rest and mate in the tree was 2～7 h once.Setting up alluring tree should be on sides of ventilate and sunny forest road or in forest windows with a less crown density.The forest horder having a certain distance from the host plant is better.Alluring the adult beetle with filter paper and block alluring core made of extractives from leaves and twigs of Melia azedarach L.soaked in 5 solvents.It was showed that toluene,acetone,ethanol were better than the other two solvents,especially the toluene with which the time of a single adult beetle biting alluring core was up to 37min 46s,and adult male showed blowing action.Through the test by infra-red instrument and analysis of alluring effect,it was supposed that the active alluring compositions in bead tree would be compounds of alcoholates and aromatics.In forest stands the control of the adult beetles with chemical insecticide indicated that 8% “green mine”at 300× dilution at 25 days after treatment had the best effect.It was better of 15 days after treatment if at 400×dilution of 50% methamidonhos or at 400×dilution of omethoate.

The influence of urban air pollutants SO₂ and Pb on the Comstocki mealybug's population density in Ginkgo biloba (Linn.)and Fraxinus Chinensis (Roxb.) were stuidied in Taiyuan City.The accumulated contents of environmental air pollutants SO₂ and Pb in the bodies of the scale insects, their host trees and natural enemies were determined by the method of analytical chemistry.The results showed as follows: 1.Pseudococcus comstocki (Kuwana) could parasite on Ginkgo trees,and brought about damage severely was found for the first time. 2.The Air pollutants,sulphur dioxide and lead,were absorbed and then accumulated in the bodies of the scale insects,their natural enemies,and the host trees (Ginkgo and Fraxinus)。 3.The Air pollutants,sulphur dioxide and lead could promote the development of Pseadococcus comstocki compared with the light polluted areas,oviposit period in the heavy polluted area was moved up 2～3d,oviposit amounts increased by 20.7～29.4 Ova/each in G.biloba and 32.5～49.9 Ova/each in F.chinensis. 4.The Air pollute level,pollutants contents in the bodies of the host trees were positively correlated with scale insect population density (SIP). The greater pollutants contents of host trees,the greater its SIP was. 5.The heavy pollution environment had changed the amino acid component of the trees. In the bodies of G.biloba the content of 13 amino acid component was increased by 24.4%～76.19%;the total carbohydrate and soluble carbohydrate were increased by 1.78% and 6.46% respectively. 6.Pseudococcus comstocki could develop largely in the pollution environment, the responsible reasons could be the weaken resistance of the host tree,the reduction of natural enemies and the improvement of scale insect tolerance.

The EAG responses of male Holcocerus insuleris Staudinger to standard compounds Z3-14:Ac,Z3E5-14:Ac,E3-14:Ac and Z9-14:Ac were strong,but only Z3-14:Ac showed an obvious attraction and specificity in trapping tests.On an average,2.66 male moths were caught by a trap baited with 500μg of Z3-14:Ac per day,which was 1.8 time as many as the moths caught by a trap baited with one virgin female.The attractant-baited trap can be used to detect both the presence and density of the moths in the field.The sex attractant Z3-14:Ac discovered will provide a new way for integrated prevention and control of Holcocerus insuleris Staudinger.

The wood of artificially infected 3-year-old black pine,naturally infected over 15-year-old black pine and masson pine were extracted and purified elementarily by high pressure boiling and CHCL3/base Procedures.The results of bioassay by application of extracts to seedlings of black pine and masson pine indicated that wilting toxic compounds existed not in healthy pines and naturally infected pines which had died for 1 year,but in naturally and artificially infected pines which were still alive.After each of primary purified compounds was analyzed qualitatively by GC/MS System,benzeneacetic acid and 2-methoxycinnamic acid were found only in wilting toxic compounds and benzaldehyde was found in all compounds including toxic and non-toxic ones.Both benzeneacetic acid and 2-methoxycinnamic acid are phenolic compounds and important secondary metabolites in plants.It follows that wilting toxic substances related to benzeneacetic acid and 2-methoxycinnammic acid were abnormal metabolites synthesized in Bursaphelenchus xylophilus infected pines,and benzaldehyde was a normal metabolite of pines.

The average percentage of tracheid volume is over 90% for softwoods species. Gas permeability of softwoods is in close relationship with the flow of gas through the tracheids. The thorough knowledge of the gas permeability of softwoods can be gained by the flow-resistor of tracheids for the flow of gas. Based on the structural model for tracheid, the expressions of flow-resistors of tracheid in three directions of grain are reduced with the theories of fluid mechanics. The gas permeability of tracheids also calculated from their flow-resistors in this paper. The calculation show that flow-resistor can depict the resistance distribution in tracheid and the differences in gas permeability in three directions of grain. The flow-resistor is a useful way of studying on the gas permeability of softwoods and it can reveal the flow nature of gas through wood at level of woody cells.

Hand two-stroke gasoline engine is popular in China. The operation life of cylinder, which is a very important part in hand two-stroke gasoline engine, is always less than 800 hours because of its' operation performance, structure, material, as well as surface strengthening technology. Based on tribology, the reason why cylinder doesn't have long operation life is analyzed, and a new type of cylinder plated with two layers of metals is presented in the paper. It is demonstrated that the operation life of the new cylinder will be up to 1000 hours under the existing technical conditions in domestic plants.

Fiber length within trees of plantation of Cinnamomum camphora increases from pith to bark in radial direction and it levels off after the 10～11 rings. Wood basic density decreases from pith to the 4^th ring, then increases gradually and levels off after the 9^th ring to bark in radial direction. The relationship model of fiber length (FB) of camphortree to tree age (x) is FB=626+73.5661x+0.4171x²-0.3639x³+0.0157x⁴-0.0002x⁵(r²=0.9545,1《x《40) and that of wood basic density (BD) is BD=0.4674306/[1+0.095907x³·EXP (-0.1306871x)] (r²=0.8059,1《x《40). Variation of fiber length within a given tree of Cinnamomum camphora is greater than that between trees. Variation of wood basic density and hot-extracts content are distinctly different from fiber length and their variation between trees are greater than those within a given tree of camphor. Juvenile wood range of camphor trees is within 1～7^th or 1～9^th rings near pith. The significant difference of fiber length between juvenile and mature wood within a given tree of camphor was found. No clear differences were found in wood basic density and hot-extracts content between juvenile and mature wood. Growth rate has no distinctly negative effect on fiber length, basic density and hot-extracts content of camphor tree. Variation of wood properties within camphor trees is very small and there is great variation of wood properties between the trees. Stem form of camphor trees is not straight and often lean in stand. Additionally there is more serious interlocked grain within trees. Controlling tree stem form and better its interlocked grain are main ways to improve wood properties of camphor trees through silviculture and tree genetic breeding.

Based on the calculation of economical benefits and ecological benefits of different operational models,and used of Multi-objectives Decision and Analytic Hierarchy Process,the comprehensive benefits of different operational models,which include economical benefits and ecological benefits,were calculated in this paper,which provides the scientific scheme for determining the productive technology in cutting area.The results showed that the clear cutting operation by suspended cableway skidding is the optimum model,which is suitable to be used in the north of Fujian province and other areas.

The anti-swelling effectiveness(ASE)and MOE/MOR of masson pine and poplar treated by chlorothalonil,ACQ and copper citrate were conducted according to Chinese national standard in this paper.The results indicated that chlorothalonil had little effect on ASE of Populus tomentosa at the retention of 11.48 kg/m3 while the ASE of treated wood at other retention increased between 3.9%～28.0% in soaked condition according to GB1934.2-91.MOE of Pinus massoniana treated with chlorothalonil,ACQ and copper citrate was not significantly changed as the control,but MOE of Populus tomentosa treated with ACQ and copper citrate increased 6.3%～8.1%.MOR of both Pinus massoniana and Populus tomentosa treated with Chlorothalonil,ACQ and copper citrate was not significantly changed.

The increased deposition of atmospheric nitrogen due to the air pollution has exceeded the demands of forest ecosystems in many areas.The chemical and biochemical reactions of nitrogen in soils have significant effects on the production and consumption of H⁺.The balance between the inputs and outputs of NH⁺₄ and NO^-₃ determines the rate of acidification of the soil-soil solution system. Excessive nitrogen deposition will enhance the nitrification of NH⁺₄ and the leaching of NO^-₃,which are the processes of strong acidification.An increase in the NO^-₃ concentration will increase the acidity and aluminium concentration in the soil solution.Basic cations will be leached out for accompanying the NO^-₃ leaching,resulting in the acceleration of soil acidification.Soil acidification is harmful to forest.

A series of techniques including the analysis of variance,χ²-test,association coefficient,Ochiai′s coefficient,Czekanowski′s coefficient and Jaccard′s coefficient were used based upon a 2×2 contingency table to determine the overall association of all species,the statistical significance and the coefficient of the each species-pair association of the 48 dominant species in the vegetation layer in C.kawakamii forest.The results showed the inter-specific association of dominant species in the layer in C.kawakamii forest can be adequately interpreted by using the techniques mentioned above.The overall association of all species is significantly positive.By AC values analyzed,464 species-pair are positive and 655 species-pair are negative,and the others are fully independent.1128 species-pair were checked by χ²-test,in which 27 species-pair were observed to have significant positive association at P=0.01,18 species-pair at P=0.05 and 17 species-pair revealed significant negative association at P=0.01,94 species-pair at P=0.05.The results still showed only 5 species,such as,C.tibetana,S.tzumu,C.fabri,C.subavenium and H.fragrans,are significantly negatively related with C.kawakamii,which is relatively weak with the other majority species in the layer in C.kawakamii forest.

By the methods of sampling soil profiles which A,B,and C represent humus horizons,illuvial horizons,and parent materials horizons respectively,relationships between the activities of soil enzymes (which include catalase,invertase,protease,and acid phosphatase) and plant species diversity in three secondary successional plant communitites of forest ecosystem in Mt.Jinyun were studied in this paper.Results showed that different degree′s correlations existed between soil enzymic activities and plant species diversity indice (PSDI) which included Shannon-Wiener H′index and Hill′s species diversity indice family N_A,moreover,the degree of correlation depended on the horizon of soils,the type of enzymes,and the life form of plants (i.e.,tree,or shrub or grass).The degree of correlation between PSDI and soilenzymic activities decreased by the orders of A→B→C.The most significant correlation with PSDI was the activity of soil catalase,and in turn,was the activity of soil invertase,On the whole,the correlation between soil enzymic activities and tree layer′s PSDI was the most evident.Tree layer′s PSDI were positively and significantly (P<0.05) or very significantly (P<0.01) correlated with the activities of catalase and invertase of A and B horizons,and of protease and acid phosphatase of A horizons.Grass layer′s PSDI were also positively and significantly (P<0.05) correlated with the activities of catalase and invertase of A horizons.Shrub layer′s PSDI were not significantly correlated with soil enzymic activities.

Phosphorus is an important element for larch (Larix gmelinii Rupr.)root development.P-availability in rhizosphere is close with root exudates or excretions,e.g.,organic acid exudation,proton excretion.These materials from roots will affect pH value of rhizosphere.The aim of this paper were to study on pH changes at different P-stress conditions,and to test on the relation between available P and pH in rhizosphere.This work was carried out under pot experiment and field soil smaple analysis.Larch seedlings,1 and 2-year-old,were planted into sand pots.Nutrient solution with different P contents (0,0.035,0.071 and 0.142g·L^-1 respectively) were supplied everyday.There were 2 replicates for 1-year-old seedlings,5 replicates for 2-year-old seedlings at ecch P-level treatment.After 1-year-old seedlings growing for 40 days and 2-year-old seedlings growing for 90 days,seedlings were taken out and used to visualize acidification by means of an agar plate technique.The result showed that pH of rhizosphere decreased from 6.40 to 4.73～4.84 in 1-year-old seedlings and to 5.30～5.50 in 2-year-old after 36h incubation.Average pH decreased were 1.56～1.67 for 1-year-old seedlings,and 0.90～1.10 for 2-year-old seedlings.There was not significant,for pH variations in rhizosphere,among four kind treatments.The pH change was not affected by P-level.The result of soil sample analysis,from 12-year-old,21-year-old,and 40-year-old pure larch stands respectively,indicated that the pH changes in rhizosphere is 0.11,0.04,and 0.09,respectively,lower than that in the non-rhizosphere,acidification is not significant,While the available P in the rhizosphere is 18.1%,86.5% and 23.4%,higher than that in the non-rhizosphere in three stands.The correlation between pH variations and available P was not remarkable at this analysis.This means that there was no relationship between the available P and pH change of rhizosphere in larch root system.

Lancang River Basin is a typical mountain ecology system.With the cooperation development of the basin,mountain ecology system in this area is destroyed easily.Forest cover is a key fact about region environment changes resulted by human action.Monitoring forest cover is very important for sustainable development of Lancang-Meigong international river.The main purpose of this study is to develop a monitoring methodology to acquire forest cover in mountain area of Lancang River Basin.Study results show that:the approach of monitoring forest cover in mountain area based on NDVI process such as in this study is of well practical value.This methodology is simple and the process is easy performed.Accuracy of monitoring forest cover satisfied the need of the cooperation development of Lancang River Basin.The methodology is suitable to apply in this mountain area.

Thirty superior trees of Chinese fir from eight provinces were analyzed on genetic variation with RAPD method.A total of 284 bands,including 190 polymorphic ones,were produced with 26 primers, and mean genetic distance between the thirty superior trees was 0.4909,indicating a high level of genetic diversity among the tress tested.Two superior trees,coded as ZJZ 01 and JXS26,showed a high value in genetic similarity,which meant that only one of them could be essentially preserved in gene bank.The clustering analysis indicated that most of the superior trees could be clustered at a relatively high genetic distance and rich genetic variation could be expected in the superior tree population.This might be valuable for marker-assisted germplasm collection,parent grouping in hybridization and genetic diversity evaluation on breeding materials in improvement of Chinese fir.

CAD system and NC-working on the sawteeth shape were disscussed.Automatic programming was realized by senior language in this system and by means of test,conclutsion was available satisfied.