A semi-theoretical model for rainfall interception of forest canopy, which combines the methodology of both theoretical model and empirical model, was presented. The new model tallies with data very well, and with a theoretical model.

Based on the data collected from sample plots with an area of 10000m², the species composition, physiognomy, and spatial structure of Castanopsis kawakamii community in Sanming, Fujian, were analysed. The community is composed of 110 vascular plant species belonging to 42 families and 68 genera, 67.6 percent of genera contain only single species. The spatial patterns of dominant tree populations, except Castanopsis kawakamii which exhibits random dispersion, conform to aggregated distribution. The tree layer can be divided into 3 sublayers in terms of height. The comparative analyses on life form spectrum, leaf characters and species diversity of the community showed that this forest is a transitional type from south-subtropical rain forest to mid-subtropical evergreen broad-leaved forest.

Explants of hybrid poplar 741 [Populus alba L.×(P.davidiana Dode+P.simonii Carr.)×P.tomentosa Carr.] were transformed with Agrobacterium tumefaciens LBA4404 harboring the expression vector pBtiA containing two insect-resistant genes. Conditions for selection of poplar transforments, especially the critical concentrations of Kanamycin(Km') were determined. 80% of the transforments selected on rooting medium containing Km' gave out positive results by PCR detection. The gene-transformed plants preliminaries selected were given to insect feeding tests with Clostera anachoreta Fabricius and Lymantria dispar Linnacus.And the tested insects were divided into four groups, high, middle, low and control according to mortality. In the meantime, the insect mortality in fixed period and the effects of delaying the growth and development of insects were comparatively studied to provide the basis for selecting plants or clones, which significantly resist to insect. The results of detailed insect-bioassay and molecular biology analysis demonstrate that the two foreign genes have been integrated into the genomes of insect resistant plants. Transforments with normal phenotype, growth rate as that of the non-transformed control and high insect-resistant were selected and accounted for 38.1% of the transformed tested.

Absorption and utilization of ³²P of Larix olgensis Henry and Fraxinus mandshurica Rupr, applied by pouring and with tube, were studied in pure and mixed stand. The result showed that absorption and transport of ³²P of trees were very fast, and ³²P reached crown at the date treated. ³²P distributing in higher level of crown was the most; that in middle level of crown came second; and that in lower level of crown was the least.³²P distributing in sun face of crown was more when appling ³²P by pouring; while that in shade face of crown was more when appling ³²P with tube. Absorption of ³²P of trees in mixed stand was more than that in pure stand when appling by pouring; while that in pure stand was more than that in mixed stand when appling with tube. Absorption of ³²P of F.mandshurica was more than that of L.olgensis in differnt stand type. Trees could exchange³²P directly through root system connection, and the mount of exchange of ³²P between different tree species was the most in mixed stand. The nutrition relationship between L. olgensis and F.mandshurica was harmonious, and in mixed stand the root system connected more extensively and distributed more rationally, which improved P nutrition condition of trees and raised productivity.

In order to update the forest resource data of subcompartment in forest bureau and forest farm in natural forest region without human disturbance, combined with integrated stand model, stand-level growth model group is developed based on 848 permanent plots of forest management inventory in 1997, taking Wangqing Forest Bureau in Jilin province as an example. The model group is made of many growth or change models used in stand measurement and calculating factors, such as stand density index, mean height, basal area, form-height, canopy density. By composing tree species of the subcompartment, taking site class index, stand density index, and prediction interval as independent variables for updating the data of natural growth subcompartment, the model group is more suitable for updating the data in the natural mixed-species and uneven-aged subcompartment. Given the stand factors of subcompartment, such as mean height and mean diameter of stand composed tree species, age, number of stems per hectare, canopy density, volume of open grown tree, the forest resource data of subcompartment without human disturbance can be updated completely and predicted continually by using the proposed model group.

The characters of gap edge effect of the forest communities are studied in Longxi Mountain, Fujian Province. The species diversity and ecological dominance as well as the index of the edge effect of 27 forest gaps which in different stands and different developing periods are measured by means of using Shannon-wiener index, Simpson index and the index of the edge effect. The results show that based on the measurement of the species diversity, the index of the gap edge effect in subtropical forest communities of Longxi Mountain is about 0.6～2.5, and on the basis of the ecological dominance index, the former result is about 0.4～1.3. The edge effect in gap edge areas have the trends to increase the species diversity of forest communities. This study can provide theoretical basis for maintenance of species diversity and forest management.

In this paper, more than 70 species of cultivated woody plants in the Bejing Botanical Garden have been classified according to the combination characteristics of occurrence dates of different phenophases including leaf emergence and leaf coloration, leaf emergence and all leaf shedding, leaf coloration and all leaf shedding, and first flowering and leaf emergence. This kind of plant classification has provided an useful procedure for objectively evaluating ornamental values of different woody plants in respect of the seasonal aspect. By selecting woody plants with specific phenophase combinations in the plant landscape making, the spatial and temporal rhythm of a landscape can be strengthened and the dynamic relationship between various seasonal aspects in the landscape can be harmonised, so that the aesthetic perception will be fully demonstrated.

Based on the studies of geographical distribution of dovetree, a GIS, named INDRISI, and designed software of ecological information system GREEN, were applied in this paper to find the climate parameter suitable for dovetree growth, from which the natural distribution scope of dovetree was defined. Furthermore, according to the prediction of climate change in 2030 by GCM s, the possible effects of climate changes on the distribution of dovetree were predicted. It suggests that the geographical distribution of dovetree will change in 2030 with 0°18′～1°18′ longitude moving toward west in the east boundary and 0°18′～1°54′ longitude toward east in the southeast part of west boundary and no changes in the south and north boundary. By 2030, the area of dovetree will decrease 20% compared to nowdays. The effect of climate changes on dovetree was further discussed according to its biological characteristics and adaptation to climate changes.

Seed production, interval yielding and bearing habits of different clones were analysed systematically based on the data from 1973～1995 in the seed orchard of L. Kaempferi on Dagujia Forest Farm, Liaoning Province. The Primary seed orchard with 158 clones was established in 1965 coving an area of 14.7 hectares. The mother trees are taller due to failure to keep the height under well control. Seed collection started in 1973 though a few of trees flowered and beared in 1971. Up to the year of 1995, 1935.58kg seed was harvested in total. Seed production was quiet low within 16 years since the orchard had been established, and the maximum yield was no more than 2.1kg/hm²·a. Seed yield increased to 25.0kg/hm² when the orchard was 25 years old, yet productivity still remained in low level (5.81kg/hm²·a) during the orchard was 22～26-year-old. Interval yielding was obviously in the seed orchard of L. Kaempferi and aboundant year occurred 5～6 year interval. There were significant to extremly significant positive correlation between seed yield and age of orchard, number of producing trees, but significant negative corretion was found between seed qulity(Percentage of empty seeds) and age of orchard, number of producing tree, seed production. Significant to extremely significant positive correlations were also found between crown diameter of mother trees and cone production in aboundant year, total cones produced in recently three years, but there was not any obvious correlation between the height of mother trees and cone yielded. Cone production differed obviously for different clones. Rank correlation analysis indicated that there was significant correlation between cone yield at the early and final stage. It is possible that the early selection of high-yield clones of L.Kaempferi can be conducted according to the cone yield in the first three years, and five years later, final selection could be made according to cone yield in the first eight years. The main factors to lead low productivity of the Jepanese Larch Orchard are extremely difference of seed production on-year and off year, a long interval period between on-years, and less high-yield clones.

Crown structure (including vertical distribution of primary branches, crown form, vertical changes of branch inclinations, vertical distribution of leaf area and cumulative leaf area index) of intensively and extensively cultivated poplar plantations were studied here. The results showed that the layer with maximum branch length of trees in intensive management plantation was relatively lower than that of extensive ones. Most trees in intensive management plantation were with coniform crowns, but in extensive management plantation, crown form appeared parabolical cylinder crowns. The distribution pattern of primary branch of trees in intensive management benefit to light interception. Branch inclination angle was also varied significantly with crown length. The estimated LAI by destructive method was 3.0362 m²m^-2 for intensive management plantation, and 2.1786m²m^-2 for extensive management plantation. The CLAI for intensive and extensive management plantations can be simulated by the folowing models: I_CLAI=0.2 607*Z^1.8030e^-0.1643Z(R²=0.9919) and E_CLAI=0.0639*Z^{2.64 80}e^-0.2530(R²=0.9960) . If simulated by the crown length of standard trees in two plantations, the CLAI was 3.1221 m²m^-2 and 2 2619 m²m^-2 for intensive and extensive management plantations, which was only about 2\^8% and 3.8% difference compared with these by destructive method estimations respectively. There were high linear correlation relationship between the standard tree and simulated model for both plantations. The cultivation measures have significant effects on the crown structure. The conical\|shaped crown, large branch inclination and higher CLAI are contributed to the higher productivity for intensive management poplar plantation.

Based on setting up the model system of growth and yield, management model system of Masson pine plantation was established by studying the effects of site, provenance, site preparation, fertilization, and thinning on stand growth. According to cultivation objectives, cutting age and economic evaluation result of multitudinous silvicuture schem were optimized and compared one by one using the management model, then optimum cultivation patterns for different site indexes were obtained. The results showed that cultivating large timber, middle wood and small logs by the optimum cultivation patterns, their cutting age were respectively shorter 4～6a, 9～12a, 8～12a than those being used at present. IRR was respectively raised 1.6%～2.8%, 1.8%～4.1%, 2.1%～4.0% than those of conventional cultivation patterns. NPV was respectively increased 1300～2790, 2009～3447, 1137～3168 yuan·hm^-2. IRR% of optimum cultivation patterns were more than 12%. To cultivating building timber, high planting density does not make good economic benefit, and rational thinning may raise economic benefit. The main models were significance at levels of 5% and 1%, by using F- test and residual error analysis, so management model system and optimum cultivation patterns may be used in study area.

Botryosphaeria Ces. et de Not., its a sexual phase is Dothiorella Sacc., causes canker of many varieties of trees and its distribution region is very wide. These two agents cause molecular gene diversity. PCR-amplified 28S rDNA products of 30 isolates from 5 regions and 14 varieties of host trees were the same. The polymorphism on digestion with six restriction enzymes was nearly the same. So, the 28S rDNA-PCR-RFLP analysis was not suitable for differentiating the species within genera. RAPD analysis of all the isolates showed that there was abundant polymorphic DNA within the genera(92.81%). All the tested isolates were divided into 13 clusters according to 0.845 similarity. One part of isolates manifested the differentiation because of different origin and host. The pathogen of Cedrus deodara canker was proved to be B.dothidea according to its DNA polymorphism. So, the host of the pathogen was very wide, including angiosperm and gymnosperm. Two primers of RAPD analysis, K16 and R14, could be the identification primers as differentiating the isolates of Shanxi province and Hunan province from others. RAPD analysis demonstrated that the traditional taxonomy of B.berengeriana de Not.f.sp.piricola (Nose)Koganezawa et Sakuma as the specialization of B.berengeriana de Not. Was reasonable. And these two pathogens causing apple canker were different species from that one causing Poplar canker.

After the host callus cells were inoculated with the toxin, the many bubbles in cell plasma were observed in 2 days. The toxin could induce the more O₂ and spur a peroxidation reaction of the lipid in host callus plasmolemma. And then lead to change the lipid acids composition of the plasmolemma. The toxin could also make the quantity of MDA increased in 4h, and the electrolyte leakage in 6h. Finally, the plasmolemma was damaged, and the cells were killed.

Biochemical index changes of Populus ‘beijingensis’ bark induced by the formation of associations with vesicular arbuscular mycorrhizal(VAM)fungi and their ralation to canker resistance were studied. The results showed that mycorrhizal formation was positively correlated with relative turgidity, enzyme activities(peroxidase and polyphenoloxidase), available phosphorus and total phenolic content of bark, but negatively correlated with total soluble sugars in bark. The growth of Dothiorella gregaria was negatively correlated with VAM formation. VAM fungi increased canker tolerance of poplars by promoting the uptake of water and nutrients(mainly phosphorus), which in turn increased the growth and vigor of trees. Induced peroxidase and polyphenoloxidase activities of poplars should result in increases in substances such as phenolics which are likely to be important parts of the canker resistance mechanisms of poplars.

Poplars was seriously attacked by insects usually in many areas and insect resistant poplars are expected in forest production. In the experiment, the modified Bacillus thuringiensis (Bt) δ-endotoxin gene and proteinase inhibitor(PI)gene were contransformed to the explants of Populus nigra mediated by Agrobacterium tumefaciens. The integration of Bacillus thuringiensis gene and proteinase inhibitor(PI)gene were confirmed by PCR analysis and Southern hybridization. The results of bioassay showed that the transgenic plants had toxicity to the larvae of Lymantria dispar L., and that the transgenic plants containing Bt gene and PI gene had enhanced toxicity to larvae by comparison with plants containing only Bt gene.

Physokermes shanxiensis Tang is a newly found pest of ornamental plants in China. In recent years it has caused serious damage to Picea meyeri in the central part of Shanxi Province, China. In this paper, its hosts, distribution and damage to Picea meyeri are reported; the morphology of immature stages are described and the bionomics is observed. The result shows that this scale develops one generation a year in Taigu county, Shanxi Province, overwinters on 1-year old twigs and needles in second nymphal stage, adult females and males emerge in early\|April and late-April respectively, and the feeding or damaging peak is from early-April to mid-May. They reproduce bisexually. Each female lays 15～1143 eggs, 602.3 on an average. The natural enemies include Harmonia oxyridis(Pallas) and Adalia bipunctata (Linnaeus), the former one is more important. Besides, the control measures are also proposed.

The nature of moisture flux and heat flux in wood pre-heating is analyzed by means of coupled flux equations,which are derived from the linear theories of non-equilibrium thermodynamics.The coupled flux equation is solved by integrating on the boundary of the wood sample and the moisture change in the sample is work out.The calculation is in agreement with the previous results from experiment.It shows that the coupled flux equations are effective on analyzing the coupling between the heat flux and moisture flux.They can both depict the heat flux and moisture flux qualitatively and also estimate the magnitude of flux quantiatively.Because the temperature inside wood sample is lower than that of pre-heating,moisture thermal diffusion occurs due to the Soret effect and the moisture of wood sample will increase to some degree in the pre-heating process.During that period,the moisture and energy transported into wood amount to almost all of both total magnitudes within two hours.The conclusions for wood pre-heating obtained in this paper can be used in the wood drying techniques and are useful to practical production.

The wood samples of 20 open-pollinated families taken from a 13-year-old progeny test of masson pine were used to study the genetics of wood chemical compositions including percentages of ash,pantosan,lignin,holocellulose,hot-water extractive and 1% NaOH extractive.The results showed that there were significant differences between families tested for wood chemical compositions,basic density and growth traits which were found to be under moderate or strong genetic control.Among 6 chemical components of wood,the heritabilities of contents of ash,pantosan and 1% NaOH extractive were higher than ones of content of lignin,holocellulose and hotwater extractive.The growth traits such as tree height,diameter at breast height and stem volume were significantly and negatively related to wood basic density and seemed to be independent of wood chemical components.Genetic correlations suggest that ash and hot-water extractive content could be good indicators to predicate percentage holocellulose and lignin respectively.The absolute differences between families for holocellulose and lignin content are small,however,i.e.2 to 3%,suggesting that it is impractical to breed for increased cellulose content through a selection program.The differences among individuals or clones can be utilized through vegetative propagation.

The succession process of evergreen broadleaf forest in the subtropical zone of China commonly covers coniferous forest stage,mixed forest stage including both coniferous and broadleaf trees but taking the coniferous tree as the dominant component,mixed forest stage taking light-loving broadleaf tree as the dominant component,ever-green broadleaf forest stage taking light-loving broadleaf tree as the dominant component,climax stages divided into two stages based on the spatial pattems of dominant tree species:unperfectly developed climax stage and perfectly developed climax stage.According to view of the above,the deliberated ever-green broadleaf forest community in this study was judged to be in uperfectly developed climax stage.The extent of population extension of strongly light-loving tree species was positively correlated with the disturbance intensity.The disturbance leading the strongly light-loving tree species to be come the first dominant species of the community was called disturbance leading regressive succession.The disturbance leading the strongly light-loving tree species to be a dominant species of the community but not the first dominant species was called disturbance non leading regressive succession.The intensity of a disturbance leading regressive succession was stranger than that of a disturbance non leading regressive succession.The judgement of succession stage and the evaluation of disturbance intensity form a set of material on the judgmet and the evaluation of succession situation for a natural forest community.

Based on the data collected from sampling plots in Batula luminifera natural forest community located in Shaowu Fujian Province,the important values of main tree species in the comnunity were determined,the community appearance,vertical ctructure,and population dynamics were analysed.The results showed that the community was dominated by Betula luminifera,Catsanopsis lamontii and Liquidambar formosana. The community could be divided into 4 layers.The tree layer could be divided into 3 sulayers in terms of height.The dominance of Betula luminifera in the forest will decrease as the succession proceeds.

This paper deals with the morphological and quantitative characters of secondary xylem of Aegiceras corniculatum and Sonneratia caseolaris. The relation between the structure of wood and the environmental influences has also been discussed.The features of small vessel diameter,many vessel numbers and high vessel frequency ensure the safety for water transportation inside plant.The ratios(2W/L), namely thickness of fiber wall(W)and width of fiber cavity(L),of both Aegiceras corniculatum(0.67)and Sonneratia caseolaris(0.45)are less than 1,demonstrating their timbers are the good raw materials for papers making.