According to the data of total solar radiation and Photosynthetically Active Radiation(PAR) in intensive and extensive silviculture poplar plantation, the equations of transforming from total radiation to ground PAR were established. Combined with the leaf Area Index(LAI) and its vertical distribution in the canopy, the extinction coefficients(k) and vertical distribution of PAR in the two stands were calculated respectively. The daily and seasonal change of K and PAR transmittance were discussed also. The relationship between PAR transmittance and cumulative LAI within the canopy was established, the result showed it is a linear model. Compared the absorbtion of PAR in two stands, since intensive culture stands with higher leaf area in the different layers of canopy, so the interception of PAR in intensive culture stand is higher than that in the extensive culture stand, this resulted the higher productivity in the former.

In this paper the potted seedlings of Pinus sylvestris var. mongolica Litv. were treated by soil drought stress to study the activity levels of SOD, MDA content, the composition of membrane fatty acids and the amount of ethylene release of needles. The results showed that the SOD activity levels first increased and then decreased with the aggravating of drought stress; The change trends of MDA content was to increase to the highest level, and then decrease to a still high level; IUFA started to decrease under serious stress; Ethylene released obviously when the IUFA level dropped drastically, at the same time the seedlings began to die. These results show that be the drought stress damage of needles of Pinus sylvestris var. mongolica Litv. is caused by membrane-lipid peroxidation; the increase of MDA content aggravates peroxidation, which causes the obvious decrease of IUFA level and ethylene evolution, and then seedlings begin to die.

The light utilization coefficents(LUC) of poplar-crop intercropping system and pure crops(CK) were both simulated by measuring the actual parameters of crop or poplar, i.e. light intensity, maximum photosynthetic rate(PR) and quantum efficiency, leaf area index in different phenophases and light extinction coefficient of leaf curtains. The results demonstrated that, in intercropping system, the crop photosynthesis cuulating decreased with the daily light cumulating decreasing, which they were linear positive correlation. The crop PR in intercropping system was slightly higher than that in pure crop system when its relative light intensity(RLI) was more than 60%, but they were similar when RLI was less than 50%, bucause its respiration did not decrease under weak light intensity. The total LUC of three intercropping systems were higher than that of pure crop system by 27.56%～48.64%. It showed that the ratio of weighted average yield of intercropping system and pure crop system was similar to their ratio of daily photosynthesis cumulating, which prove that the simulation method is practicable.

Photosynthetic characteristics for different ages of 18-year-old Chinese fir shoots at different positions within crown were measured in 3 growing seasons. Results showed that the photonsynthetic rate of current shoots was the greatest in summer(mid-season) followed by late spring(fast-growing season) and autumn(late season), while that of 1-year-old and 2-year-old shoots decreased from late spring through summer to autumn. Light saturation point(LSP) for net photosynthetic rate and dark respiration rate(R_d) also decreased from late spring to autumn while apparent photon utilization efficiency(α) increased, especially those from summer to autumn. Except that light compensation point for photosynthesis (LCP) of current shoots in late spring was remarkably higher than in summer and autumn, there was no obvious difference of LCP among different seasons. In regard to differences of shoot ages, the photosynthetic rate of current shoots was highest followed by 1-year-old and 2-year-old shoots except for the late spring that the photosynthetic rate of current shoots was similar to 1-year-old shoots. The older the shoots, the lower the LSP,LCP and R_d,but the higher the α. For the different positions within tree crown, the photosynthetic rate, LSP,LCP and R_d of all shoots decreased from upper crown throught midcrown to lower crown while α increased, particularly differences between the upper-mid-crown and lower crown were quite remarkable. Differences among seasons were thought to be associated with photosynthetic biological activities of shoots, while differences among shoots at different positions within crown were related to acclimated light environment; however, differences among shoot ages were resulted from not only the biological activities but also the light environments. The daily courses of net photosynthetic rate(P_n) were also measured. The daily course of P_n in cloudy day was single peaked and P_n was mainly affected by photosynthetic photon flux density (PPFD) but also by changes of temperature, humidity, vapour pressure deficit(VPD) and ambient CO₂ to a small extent. However in clear day, the daily course of P_n was double peaked and PP_n was significantly infuenced by temperature, humidity and VPD as well as PPFD. The high temperature and VPD and low humidity resulted in the remarkable decrease of P_n at noon. The daily courses of P_n for current shoots and shoots at mid-upper crown were more remarkable than old shoots and shoots at lower crown.

5　1600m² plots were established in Fujian Sanming Nature Reserve of Castanopsis kawakamii for the obtaining of sampling data by tally in the contiguous quadrats. Analysis of the structure and spatial patterns of Castanopsis kawakamii population indicates that the population structure of Castanopsis kawakamii has abundant seedlings, 3523 stems/hm², and big trees, 145 stems/hm², but relatively few young trees, 73 stems/hm², which is similar to that of 1981, and that the fragmentation of population structure is easily found in certain successional communities. Generally speaking, the Castanopsis kawakamii forest has not reached a climatic climax while Castanopsis kawakamii population exhibits recession. Spatial patterns of population varies with different developmental stage, with an overall trend from aggregated to random distribution, for example, K varies averagely from 1.643 to -5.990. Aggregated pattern is prevalent at different successional stages of communities. Different size of blocks has been found to have an effect on the spatial patterns. As for the endangerment of Castanopsis kawakamii, fragmentation of habitats, barries to population regeneration, decreased population nummber due to human disturbance and unstable community environment due to ecotonal locality are the main causes. Conservational strategies should be focussed on ex situ conservation as well as in situ conservation, reducing human disturbance and enhancing inter-population genetic exchange.

According to the characteristics of forestry and agriculture and the feature of agroforestry system on slope in the hilly region of Sichuan Basin, the internal structure of agroforestry system was systematically studied, and the positive and negative effects of the forest belts to the crops were investigated. On the basis of analysing the distributing pattern of the scattering radiation, the feature of water and soil loss, the distributing pattern of the yield, and the distance between two forest belts on slope, the distance between two forest belts on slope which shoud be no less than three\|fold average height of forest belt has been provided in a position to guarantee against decreasing yield. Meanwhile, a contrastive analysis on the synthetical efficiencies of agroforestry system model and agriculture system was finished. The results showed that the productivity was improved, the energy transforming ratio, and the utilization efficiency of nutrient, value and labor force were also increased in agroforestry system on slope. It was provided with the more great producing potential.

A clonal selection program of its genetic improvement had been conducted during 1981～1997 on Kaihua Forest Farm, Zhejiang Province. A multiple step clonal test and selection strategy or stepwise screening procedure was adopted to ensure accurate selection and rapid application of the best clones to plantations. The strategy included four test steps: (1)Selecting of plus individuals as ortests from the full-sib and half-sib progeny and provenance trials, and then cloning them by sproutings collected from trunk base in nursery for establishment of cutting garden. From them a lot of cuttings had been harvested for sequent tests; (2) Preliminary clonal test with a great number of clones by row plot with 5 ramets and 4 replications; (3) Second time clonal test with 15～20 clones selected from preliminary trials by row plot with 5～6 ramets and 4～6 replications; (4) Final clonal test with a few clones selected from second time test by block planting with 36～50 ramets and multiple replications to accurately examine their realized productivity. The selection criteria included growth rate, stem form, form ratio, crown form, bark rate, and resistibility. In every trial the seedlings of seed orchard and super provenance were used as controls. Generally, the selection was carried out at 4～6 years after planting. In order to accelerate the process of test and selection in favour of clonal plantation establishment as early as possible, every clonal test type may be set up simultaneously during successive years in several sites, if the clones display superior at preliminary test. In addition, a number of clones well displayed may involve simultaneously in several test trials for re-verification. Up to now 143 clonal trials with 257 clones and covering total of 81.6 hm² were established. Recently, 10 super clones were selected from original clones, based on performances on multiple step tests. The wood properties of five clones were measured. Results shown that their individual volume based on second time test and volume per unit area (hm²) based on final selection test were increased 60%～100% in comparison with the local seed orchard offsprings. However, the wood properties presented almost the same as control.

DNA was isolated from germinating embryos of 5 and 7 natural populations of Cunninghamia lanceolata and Taiwania flousiana, respectively. Two different techniques were used for the DNA isolation. Similar results in terms of quantity and quality of DNA were obtained and the economical one was selected as main method. The best DNA amplification condition was obtained after experiments. AMOVA was studied by using the software of Arlequin and PHYLIP. Results showed that the cpSSR was sensitive in revealing the genetic variation between 2 tree species and among the populations inside species, it is of special importance in studing the evolution history of coniferous tree species, gene resources conservation strategy and tree breeding strategy.

Given the stand factors of subcompartment, such as mean height and mean diameter of various tree species composed stand, age, number of stems per hectare, crown density, volume of open grown tree, the forest resource data of subcompartment without human disturbance could be updated completely and predicted continually by using natural stand growth models. These models were of taking composing tree species as updating basis, with site class index representing site quality of a subcompartment, with prediction interval substituting age, and more suitable for updating the data in the natural mixed-species and uneven-aged subcompartment. Based on 108 permanent plots from Wangqing Forest Bureau in Jilin Province, the test results showed that the predictions by using the natural stand growth models were better than those by using growth rate in production units at present.

According to the 6-year-old data of Alnus cremastogyne,the experiment analysis has been made for the 13 provenances in 5 sites. It proved that there was a highly significant difference among provenances in height (H) and single tree volume(V)(F=7.93^{* *} andF=4.83^{* *} ), and the interaction between provenance and environment was also highly significant(F=2.70^{* *} and F=2.21^{* *} ). Their genetic stability and growth adaptability have been evaluated using Eberhart etc's trait regression parameters (b_i and s²_di), Wrick's ecovalue parameter (W_i) and Additive Main Effects and Multiplicative Interaction analysis (AMMI).The estimates of AMMI were greatly concordant with the estimates of ecovalue. Age age correlation analysis results showed that there were significant correlation in heights at 6 years and 14 years(r=0.7580), which showed the reliability of early selection. The provenance heritablities and standard errors of main growth traits in H, diameter of breast height (DBH) and V were respectively 0.8738±0.0482、0.7961±0.0718 and 0.7929±0.0727. If the best provenance or 2～3 superior provenances were selected in each site respectively, the expected gain for volume is 39.03%, the average genetic gain for the volume is 27.57% respectively. According to the main effective values and stability parameters, the suitable regions for the provenances were estimated.

The study on the structure and dynamics of C.glauca populations was carried out at hills around West Lake, Hangzhou, with the methods of plant population ecology. On the basis of census of all individuals of the populations at different plots, the structure and dynamics of the populations were described. The result showed that C.glauca populations were stable intermittent populations, while the spatial patterns followed contagious type which changed with size classes of the populations. It was found that seedling or sapling class showed contagious type, while the small, middle and big tree classes exhibited radom types, reflecting the spatial patterns of the populations changed with the time during its development. Additionally, the seed and clonal regeneration or propagation of C.glauca populations in different habitats were studied and discussed, together with their ecology strategies. According to the results above-studied, the dynamic characteristics or adaptive mechanism of C.glauca populations was discussed respectively.

In this paper, two new species infesting bamboo in Southwest of China are described and illustrated,Bambusiphaga maculata Chen et Li sp. nov. and Epeurysa jiangjinensis Chen et Chiang sp.nov.,which are very harmful to bamboo by sucking sap and laying eggs. All type specimens are deposited in the Institute of Entomology, Guizhou University.

Since the use of light and the ultra-light planes to spray pure spore of Beauveria bassiana, fenvalerate,thiophanate methyl liquid etc.in ultra-low volum to control forest insect pests and diseases such as Dendrolimus punctatus,Pantana phyllostachysae in Sanming City,Fujian Province for twelve years (1987～1998).The easy temporary airport and the GPS satellite locating system were used.The operation tests were done about 941 times and test area reached 22.47 thousand hectare totally.An effective and useful operation technic was obtained and the social,ecological and economic benefits were significant.

934 to 1,022 of Saunder's gull(Larus saunderst) were directly counted at the coast around Yancheng,Jiangsu Province,in June of 1998.Another 920 flying individuals of Saunder's gull over its breeding colony were counted and 212 nests in the colony, of which 148 nests filled with eggs were found.The average nest density was 1.06 nest/hm²(XD=0.82,n=10),and the egg-filled nest density was 0.71 nest/hm²(XD=0.71,n=10). The correlation between the number of flying indivduals of Saunder's Gull over the breeding colony with the nest density and the number of nests with eggs was significant (R=0.989 and 0.978). The distribution of nests in breeding areas was tending to even distributing and inclining to random distribution (R=1.101),although Saunder's gull had the habit of colonial breeding. Moreover, about 2,550 pairs of Saunder's gull in this breeding area according to the colonial area and the egg-filled nest density were estimated.

To look for the relationship between wood structures and wood dyeing effects is a more important research field developed in recent years.Seventeen parameters of wood structure and their wood dyeing effects for 29 pieces of sample panel from 5 trees of Chinese fir from plantation were determined and based on the data to carry on the multiple regression analysis.The regression results showed that each variable of wood dyeing effects has higher relationship with the wood structures,and the multiple correlation coefficients between each variable of wood effects and wood structures were 0.5630～0.7913;The main factors of wood structures influencing wood dyeing were proportion of wood ray,proportion of tracheid,tangential thickness of cell wall of late wood and ratio of cell wall of late wood to cavity according to comparing the standardized regression coefficients of multiple regression equation.

Significant progress on the somatic embryogenesis and transformation in walnut (Juglans) has been made in the past decade.Somatic embryogenesis has been achieved in 5 species of walnut.Cotyledons and zygotic embryos from immature fruit were routinely used as the explants for inducing somatic embryogenesis of walnut.Repetitive somatic embryogenesis has been used for the clonal production of in vitro plants and for gene transformation and regeneration of transgenic plants.Using Agrobacterium-mediated transformation of somatic embryos as a method,genes of interest have been transformed into walnut.The transgenic plants successfully expressed the transformed genes.An overview of the progress on those areas in walnut was presented in this article.It focuses on the points of induction of somatic embryogenesis and repetitive somatic embryogenesis as well as somatic embryos germination and their conversion.A model of using Agrobacterium-mediated transformation of somatic embryos for the production of transgenic plants in walnut was also presented.

The total area of the world's forest was in 1995 estimated to be 3454 million hectares of which 3% was made of plantations. Forest plantation is essential forest ecosystem with fundamental functions and roles in wood production, environmental protection and landscape design. It is the supplementary function of forest plantations in wood supply that the natural forests can more efficiently used for environmental protection, biodiversity conservation and recreation. The forest plantations can sustainably managed under the preconditions of a combination of correct species selection with silvicultural arts and forestry policy by which the combination is enhanced. Exotic tree species are components of forest genetic resources and play an increasingly important role in the development of commercial plantation forests, in particular, in the tropics and subtropics. The sustainable management of forest plantations is driven by dynamic tree breeding and tree improvement and creative forest management. To practice the essence of sustainable forest management, the Chinese forestry is challenged by both technological and economic systems, however, the way by which the forest plantations can be managed towards sustainability is to reform the economic system of forestry and to follow the mechanism of market economy which has effectively been used in agriculture so that it is possible to establish forest plantation industry in China.

According to the classification system of life-form provided by Raunkiaer,the life-forms of 290 vascular plants of 10 Quercus mongolica communities in north-east China were analyzed.The results showed that the hemicryptophytes were the dominant life-forms,accounted for 32.4% of all the forest vascular plants,followed by geocryptophytes,accounted for 23.1%,mesophanerophytes and nanophanerophytes were about 14.6% and 13.9% separately.Altitude and latitude could affect the ratio of geocryptophytes.With the increasing of altitude and latitude,the ratio of geocryptophytes had a trend to develop.The regression analysis among geocryptophytes,hemicryptophytes,altitude and latitude were done.The water content in soil could affect the ratio of therophytes.The ratio of mesophanerophytes,nanophanerophytes,hemicryptophytes and chamaephytes didn't change significantly with the increasing of altitude and latitude.

Microfibril angles of bamboo cell wall in different part of culm have been measured by using X-ray diffraction(002)peaks. Its distribution shows that:(1)microfibril angle increases slightly along radial direction from the culm's surface to its interior part. The Ansade Cortex consists of amorphous material.(2)The microfibril angles of the different parts along vertical direction in the same internode are the same.(3)The relationship between microfibril angle(θ) and internode length(L) can be satisfactorily expressed as:L=b cos θ+a,in which a, b is constant respectively.

The mixture of synthetical reaction of N－Hydroxy－N nitrosocyclohexanamine potassium salt by RP-HPLC on C₁₈ column and with 70% CH₃OH-30% H₂O as mobile phase and UV detector at 230nm. Three compounds were separated well. The mechanism of separation was studied.

In this paper, the targets evaluating wood collapse defect was studied which included, three targets of collapse depth, collapse factors, volumetric shrinkage rate, and their measuring methods. The main point of 3 targets and the relationship of 3 targets were analyzed when collapse was evaluated. Based on the study of aspen wood collapse, collapse was classified,proceeding to show that different collapse should use different evaluating targets. The collapse properties of different standard Daqing Aspen were studied using above evaluating targets and classification methods.