Forest gap leads to the formation of environmental heterogeneity,which plays an important role in the distribution of species,community dynamics and biodiversity.Further,it also influences forest regeneration and succession.The influence of temperature on forest gaps based on our observations of soil suface and air(1.5 m) temperatures located at 8 direction (located at 45°,from center to interior)within the gap in a tropical secondary forest in Xishuangbanna during different seasons wee discussed. The results indicated the existence of distinctly temporal and spatial differences during different seasons due to fog,solar altitude and trees at the edge of gap indicating the influence of temperature.The maximum temperature occured at the edges of gap and not at the centre,whose position and intensity vary with time and season.In addition,the directions of heat transfer between medium(air,soil surface)varied with space and time.Especially at the noon of dry\|season,differences between air temperature and soil surface temperature wee different in sites,which even induce direction of heat transferring inverse.All these facts result in induce direction of heat transferring inverse.All these facts result in environmental heterogeneity within the gap.Further,they affected germination of seed,growth and development of seedling and distribution of plant community,which finally influenceed the forest regeneration and succession.

Different fractions of soil C were detected in Phyllostachys praecox stands. It was found that the total soil organic C (C_T) was almost the same as that of Pinus massoniana natural stands, but higher than that of Castnea mollissima stands which is adjacent to Phyllostachys praecox stands. Soil microbial biomass C (C_MB) decreased by 23.12% (compared to Pinus massoniana) and 12.63% (compared to Castnea mollissima).C_MB and C_MB/C_T declined more apparently in continuous chemical fertilizer application stands.C_MB and C_MB/C_T decreased by 61.54% and 58.82% respectively in 3-year chemical fertilizer application stand compared to the stands with mixed application of chemical and organic fertilizer. Continuous mulching with organic material in winter, however, was detected an increase in C_MB and C_MB/C_T. Soil active C (C_A) measured by 333 mmol·L^-1 KMnO₄ and C_A/C_T sustained the same level with Pinus massoniana.C_A and C_A/C_T were respective 1.39 and 1.23 times over in 3-year combining application of chemical and organic fertilizer relative to monotonous chemical fertilizer application and C_A was increasing with the mulching years. Mulching material in winter was also observed to result a growing in water-soluble C (C_WS), one times of increase in C_WS was measured from 1-year to 5-year mulching stands and corresponding C_WS/C_T increased 0.75 folds, but unactive C (C_UA) was observed no increase. Significant relationships (P<0.01) were detected between C_T and C_A,C_WS, between C_A and C_WS, between C_T,C_A,C_WS and total N(N_T), hydrolyzable N(N_H), available-P(P_A), available-K(K_A). There was no good relationship between C_MB and C_T,C_A,C_WS,N_T, N_H, P_A, K_A.

The secondary metabolites in Eucommia ulmoides organs under the same entironmental condirings were determined. Significant differences of different metabolites were showed among different plants and different organs within the same plant. Considering the contents of one kind of metabolites: chlorogenic acid:leaves>staminate flowers> bark>fruit; aucubin: fruit>leaves>bark>staminate flowers; flavonoids: staminate flowers>leaves>bark>fruit; gutta: fruit>bark>leaves>staminate flowers. Considering the contents of different metabolites in different organs, leaves: chlorogenic acid>flavonoids>gutta>aucubin; bark: gutta>aucubin>chlorogenic acid>flavonoids; staminate flowers: flavonoids>aucubin>chlorogenic acid; fruit: gutta>aucubin>flavonoids>chlorogenic acid. The results show that the contents of chlorogenic and aucubin and flavonoids in the leaves are higher than those in the bark, which indicate that the leaves can substitute for the bark. Besides the α-linolenic acid oil (51%), the fruit is also rich in gutta and aucubin, showing that the fruit is a new kind of natural resource to be developed. The contents of flavonoids are the highest in the staminate flower and lots of chlorogenic acid and aucubin are also in the staminate flower, which is a new organ needed to be developed.

Species diversity of plant communities in Baotianman was studied in this paper.Distribution trends of species richness indices,species diversity indices and species evenness indices along the community gradient were almost the same.They reflected the different species composition of different plant communities.Species richness indices of herb layer were higher than that of both tree and shrub layer,and its variations along the community gradient were higher than that of shurb layer,while shrub layer were higher than of tree layer.Species diversity indices of tree layer were lower than that of shrub and herb layer,variations of shrub layer along the community gradient were lower than that of both herb and tree layer obviously.Species evenness indices of shrub layer were higher than that of both tree and herb layer,and its variations along the community gradient were lower than that of both tree and herb layer.Species richness indices and diversity indices of the plant communities that distribute at both high and low altitude were higher than the plant communities at middle altitude.The plant communities at middle altitude had lower species evenness indices mostly,but higher values occurred in the plant communites at all altitude.The higher species richness indices and diversity indices of herb layer occurred at low altitude,the lower occurred at middle altitude.The patterns of all kinds of indices of tree and shrub layer and species evenness indices of herb layer along altitude gradient were variable.

This article dealt with the correlation between the nutrient contents of N,P,K,Ca,Mg,Cu,Zn,Mn,Fe in foliages and the height growth, current height growth, and the growth of DBH of young Chinese fir plantation during the first and second rotation grown under hill site conditions. Then the scientific basis was provided for increasing timber yield and preventing and curing soil fertility degradation from the angle of forest tree nutrition. The research results showed that there was a closely positive correlation between the growth of young Chinese fir plantation in the second rotation and the contents of N,P,Mg,Cu,Mn,Fe. The coefficient values of complex correlation was lower for the first rotation, compared with the second rotation, suggesting that there was not obvious influence of soil nutrient content on the normal growth of young Chinese fir plantation in the first rotation.

Transformation of mtlD/gutD divalent genes to Populus deltoids × P.cathayana by means of leaf disc was undertaken. Through successive selection in shoot and root induction stage under high level kanamycin pressure, 38 kanamycin-resistant rooted plants were obtained. PCR analysis showed that 28 of these kanamycin-resistant rooted plants were positive. 5 of these 28 PCR positive plants were taken out for Southern blot and Western blot, and the result indicated that 4 of the 5 plants were positive for both. This meant that mtlD/gutD divalent genes were successfully integrated into the genome of these 4 plants, and the proteins expressed by mtlD/gutD divalent genes were synthesized. The salt resistant test demonstrated that salt tolerance ability of these 4 plants was enhanced to some extent.

double cross hybrid clones of white poplar,whose hybridization combination is (Populus tomentosa×Populus bolleana)×(Populus alba×Populus tremula),as the experimental materials,the growth and physiological characteristics under water stress were studied,index system on comprehensive judgement of drought resistance ability of the clones were suggested and the drought resistance ability of the clones were judged comprehensively.On this basis,the indices of adaptability to drought and of productivity to drought were analyzed.The plant height,single leaf area,net photosynthesis rate, transpiration,leaf water-losing rate and the ability of osmotic adjustment were suggested to be used as comprehensive judgment indexes in drought-resistance clones selection.

Thirty three trees from a seventeen years old plantation of Chinese tulip tree (Liriodendron chinense) in Fenyi county, Jiangxi Province were randomly selected, and their basic density, and fiber length of each growth ring for the increment core samples at breast height were measured. The results showed that the radial pattern appeared a “V” type curve for basic density and an exponential one for fiber length. Age-age correlation analysis showed the earlier selection for basic density and fiber length was at a cambial age not younger than 5 at the breast height. Compared with provenance trials with 15 sevenyears old provenances, analysis results showed that the radial pattern curves were basically parallel for both seven-year-old and seventeen-year-old plantations, and indicated the earlier selection was also applicable(α=0.05) for the provenance trials. Finally, the variation trend of mean age-age correlation coefficients (MACC) with age interval was discussed. MACC of both basic density and fiber length in L. chinense decreased with the increase of age interval value although the decreasing rate of basic density was more violent. According to the MACC analysis, the result also suggested that it was feasible for earlier selection of the two main wood characteristics, but earlier selection would be more reliable when the plantation age is older than seven years old in practice.

Based on introduction and selective breeding of Michelia tsoi, genetic variations of 6 M. tsoi types were determined using ISSR marker assays. 12 primers were screened from 30 primers, and total 134 DNA bands were amplified, 67 of which (50%) were polymorphic. The average number of DNA bands amplified by each primer was 11.167. DNA profiles based on ISSR16, ISSR19 and ISSR2 have revealed potential diagnostic fingerprints and specific bands for various types. The ISSR specific bands are useful for the identification of cultivated germplasm, and testing trueness of cultivars. Key steps of ISSR-PCR analysis techniques and application to testing trueness and purity of M. tsoi types were discussed. A dendrogram was constructed by using UPGMA algorithm.

Chinese fir is an important timber species in south China.Since the productivity of Chinese fir plantation had been seriously declining after successive planting,the sustainable management of Chinese fir plantation becomes extremely important.In order to select the clones growing fast in degraded soil,High-nitrogen-efficiency-genotypes of Chinese fir clones were studied under three sorts of nitrogen stresses(glight nitrogen deficiency,medium nitrogen deficiency,heavy nitrogen deficiency)throught the physiological process analysis of Chinese fir clones.The results were as follows:there were significant differences in nitrogen utilization efficiencies among different Chinese fir clones.As the degree of nitrogen stress increased,nitrate reductase activities and light saturation points of different clones decreased,CO₂ compensation points increased and responses of different clones to nitrogen stresses became more obvious.The tested clones may be classified into three categories:strong,weak and intermediate capacity to nitrogen stresses according to their responses to nitrogen stress.Among the tested clones,No.163 and No.301 were the High-nitrogen-efficiency clones that could produce high yield in the site of low nitrogen concentration and ought to be popularized for poor site.These clones have practical significance to buffer the increasingly sever soil degradation and provide a new approach to control the productivity decline for successive planting of Chinese fir.

The two international provenance trials of Casuarina junghuhniana Miq. were established in Zhangzhou, Fujian Province and Dianbai, Guangdong Province in southern China. The 28 seedlots of seeds all came from Australian Tree Seed Centre, CSIRO. A complete randomized block design was employed for each site, with 16 or 25 trees per plot and 4 blocks or replicates. From 1 to 4 years old, tree height (H, m) and diameter at breast height (DBH, cm) were measured, calculated single tree volume (V) and tree survival percentage (S, %). The results showed that there were significant differences in all traits between sites, between provenances, and between interaction of provenance x site (G x E) , which indicated that those provenances were not only genetic variation in tree growth indexes at each site but also genotype x site interaction. Provenance broad heritability was calculated. Using H, DBH,V and S at 4 years, by the Multiple Objective Strategic Decision Analysis method, provenances in each trial was optimized and ranked. On the purpose of high wood yield in plantation, the selected provenance rate was 25% of the total seedlots in the trials. Then the 7 seedlots 19238, 18847, 18853, 17877,18950,18852 and18949 at Zhangzhou (E 966), and the 7 seedlots 18844, 19489, 19240, 17877, 19491, 19490 and 19239 at Dianbai (E 968), were screened out as better provenances. These seedlot comprehensive estimating index values (Wi) were significantly bigger than the mean value of the whole seedlots. Genetic variation coefficients and broad-sense heritability (H²) of provenance in all traits were estimated from 1 to 4 years after planting. The early age-age phenotypic/genetic correlation coefficients of tree heights from 1 to 4 years old, and between H, DBH, V and S traits were all.significant positive, which could be benefited to the early age-age prediction for tree height, or indirect selection and comprehensive selection for provenance. Possible suitable areas of Casuarina junghuhniana provenances were predicted in southern China, by means of Booth's model.

The effects of sulfur dioxide pollution from local factories to the outbreak of Diprion.jingyuanensis Xiao and Zhang were studied. Simulated pollution experiment in laboratory indicated that mean relative growth rate (MRGR) of D.jingyuanenisis larvae increased by 17% compared to CK, after they were fed with pine (Pinus tabulaeformis Carr.) needle which were fumigated by SO₂ (the highest concentration in a day was 255 μL) and the difference was remarkable (n=5,α=0.05,P=0.017). This revealed that the growth of D.jingyuanensis larvae could be enhanced after they were fed with contaminated needles in certain sulfur dioxide concentration. D.jingyuanensis in polluted area was easy to outbreak. Nevertheless, MRGR of D.jingyuanensis larvae was reduced by 8% compared to CK. after they were fed with pine needles which were fumigated by high concentration SO₂ (510 μL), and the difference was striking (n=5,α=0.05,P=0.01). High concentration of SO₂ seemed to hamper the growth of D.jingyuanensis larva. In the field the damage degree and cocoons density in polluted area was higher than non pollution area. In addition, the mechanism why SO₂ pollution was able to accelerate the outbreak of the sawfly was explored. The content of sulfur in pine needle in sulfur dioxide polluted territory was significantly higher than non SO₂ pollution area (α=0.05,P=0.09),but the content of nitrogen in needles at SO₂ polluted place was lower than non SO₂ pollution area.

The fat content of adult healthy Masked civet and Nutria were measured. The value of iodine, saponification,acid PH composition of fatty acids of grease has been analyzed chemically and by apparatus. The results showed that PH acid of Masked civets fat and Nutrias fat were 0.87 and 1.79,respectively. Iodine value of them were 53.90 and 48.32;saponifications value were 98.80 and 100.23;unsaturation point were 60.05% and 58.85%. The fats of the two kinds of anincls contain the Eicosaietraenoic acid(C-20∶4) which is of great significance for nutrition and metabolism in human body.They could be widely exploited and utilized in health protection and cosmetics industry.

The dynamics of component structures and nutrient classes diversity of the arthropod community were analyzing using species and nutrient classes and guilds in different intercropping and managing jujube yard ecosystems in Taigu. The results indicated that the species diversity>guilds diversity>nutrient classes diversity in all treatment fields. The correlation among nutrient classes diversity, guilds diversity and species diversity were obviously significant (P<0.01). The variable trend of guild's biodiversity was similar to that of the species biodiversity, the fluctuation of nutrient classes diversity was less. If the species was replaced by guilds in studying the structure and function of community, the complicated network relationship among species in the community would be simplified. The function of natural enemy in the community should be evaluated on the numbers, the temporal and spatial niches of natural enemies, pests and neutral insects. The neutral insects in jujube yards arthropod community play an important role in the nutrient chain of the pests and natural enemies.

Forest harvesting slash disposal is one of the important parts of forest operations. A field survey for investigating slash disposal was carried out in a forest sector in Heilongjiang Province, northeast China. Through the research, it is explicit that slash disposal has also affected on the physical and chemical properties of soil on the harvested sites. The presented results of this study show that both of piling method and burning method do not affect the physical properties of soil very much, but impact the chemical properties of soil quite significantly, and the burning method may cause soil erosion if handling poorly.

This paper developed the theory on the three-dimensional flow-resistor network for gas permeability of softwoods from longitudinal to radial and tangential directions. The two-dimensional equivalent connection of the secondary flow-resistor network was presented for the flow of gas in the radial and tangential direction. The method had been given in this paper to determine the number of flow resistor elements in the network and the way to resolve the network. The radial and tangential gas permeability of Masson pine (Pinus massoniana) was evaluated with the flow-resistor network. Comparison is carried out between the calculated and measured values of radial and tangential gas permeability, and result shows that there is agreement between the both. The three dimensional flow-resistor network can be use to describe the mechanism that gas flows through the softwoods and to evaluate the gas permeability in longitudinal, radial and tangential directions provided that the previous work on the longitudinal gas permeability joins up with those done in this paper. The work done in this paper is useful for wood processing.

By means of ESCA, Si content of wheat straw surface was studied under different temperatures and sputtered by Ar⁺.In the cross section of wheat straw, Si content was the largest in the middle section. As temperature going up, Si content of wheat straw surface was rising after decrease. Of all selected temperatures, Si content was the smallest at 170℃ and 220℃. After surface sputtered by Ar⁺, Si content was rising with the depth from exterior to interior. The chemical surrounding of Si in wheat straw was closed to that of methyl-silicone.

The smoke inhibiting property of FRW, a new fire retardant for wood, was systematically studid by cone calorimeter and Dricon fire retardant was used for comparison. Th results showed that ,at a heat reflux of 50 kW·m^-2, the values of Smoke Ratio(SR),Specific Extinction Area (SEA), the concentration of carbon dioxide (CO₂) and the yield of carbon dioxide (Y_CO2) of FRW treated wood decreased more considerable than the untreated wood. The FRW treatment of wood had a minor influence on the generation of carbon monoxide. Both FRW and Dricon had strong smoke inhibiting effect on wood and their efficiency were similar.

The particularity about applying the principles of linear elastic fracture mechanics (LEFM) to wood were expounded. The fracture toughness K^TL_IC parallel to grain of wood of Chinese fir (C.lanceolata) and Masson pine (P.massoniana) were determined with different samples and methods. The results showed that LEMF based on isotropic material is suited for wood crack growth parallel to grain. The fracture toughness parallel to grain is a basic property of wood.

In terms of the mechanisms for the formation and maintenance of biodiversity, different hypothesis had existed, but a general theory system was not available now. Based on their research objectives, different researchers have examined the complicated interaction relationships between the various ecological factors and biodiversity, and they have obtained numerous interesting conclusions; however, many controversies have been induced at the same time. In this paper, we mainly discussed the relationships between biotic factors (such as primary productivity, biomass, the relationship between species, soil microorganisms, and etc.), abiotic factors (such as disturbance and heterogeneity, climatic and soil factors, and etc.) and biodiversity, and the effects of human being actions on biodiversity. In the end, we simply introduced the applications of the information techniques (such as GIS, RS and GPS) and mathematical methods to biodiversity field. In a word, in order to obtain a perfect theory regarding the mechanisms of the formation and maintenance of biodiversity, we should insist on the integrative idea and deeply research the interaction between the biological and the abiotic factors and the biodiversity at the different time and space scales at different layers.

The molecular taxonomy of Phytoplasmas achieved the tremendous progress due to DNA-based method was introduced from 1990s,the Phytoplasma was determined as a candidatus genus of the Mullicutes.At present,through combining DNA molecular data such as RFLP patterns,DNA sequences,nearly three hundred Phytoplasmas were classified into 14 or 20 major phylogenetic groups according to the Lee or Semmuller identification scheme,respectively.Every group or subgroup was representative of candidatus species of Phytoplasma,totally five candidatus species of Phytoplasma were published,i.e.“Candidatus Phytoplasma aurantifolia”,“Candidatus P.australiense”,“Candidatus P.australasia”,“Candidatus P.fraxini” and “Candidatus P.japonicum”.The Lee's identification scheme was listed.The problems of candidatus species concept in Phytoplasmas were discussed in detail.

The effect of cold acclimation on the freezing resistance and total soluble protein content in Populus tomentosa seedlings was studied for the first time in this paper. The results showed that in order to acquire higher freezing resistance, cold acclimation of Populus tomentosa seedlings might get through three periods, in which temperatures were -1℃、-2℃and -3℃ respectively. The freezing resistance of seedlings began to be induced by -1℃,but the third period of cold acclimation at -3℃ had most effect on the development of seedling freezing resistance. Suitable light could increase the freezing resistance and the content of total soluble protein of seedlings during cold acclimation, whereas 20 mg·L^-1 of cycloheximide pretreatment of seedlings obviously decreased the freezing resistance and the content of total soluble protein. Further analysis found that the enhancement of total soluble protein content was closely related to the freezing resistance during cold acclimation.

The calli formation and organ regeneration from different explants in vitro of Betula platyphylla were discribed.The calli of stem and petiole mainly originated from cortex parenchymatous cells in wound, and that of leaf produced from epidermis and the parenchymatous cells under it. The meristematic nodules were formed at high frenquency in developing callus . They further developed into vascular nodules which could grow at single direction and form adventitious roots. The adventitious buds occurred in the meristematic cell mass in the surface area of calli where the suberized periderm was lacking .In axillary bud proliferation way, adventitious buds originated from the epidermis and underepidermis of stem in axillary and nearby areas. The induced adventitious roots were mainly initiated from the ray cell near the cambium.It seemed that callus inhibited rooting.

The quality character, the dehydrogenase activities and the α-amylase activity of Castanea mollissima conserved materials, including the seeds and the excised embryos, were analyzed for purpose of the feasibility of long term storage associated with cryopreservation. The results showed that moisture content was the critical factor deciding the cryopreservation effects of seeds, which were desiccated down to 20% necessarily. Under the conditions of the cryoprotectants, the freezing injury reduced largely, and dehydrogenase activities remained well. Moreover the cryoconserved scale of moisture content was enlarged. A proper combination of cryopreserved factors contributed to maintain the seed vigor, the dehydrogenase activity and α-amylase activity of excised embryos during cryopreservation.

The germination capacity of Pinus tabulaeformis seeds was obviously improved after the seeds were soaked with the different concentrations of natural brassinolide. The germination rate and germination energy of the seeds were increased by 23.1% and 14.94% respectively, and the mean germination speed ( i.e. germination time) of the seeds was cut down by 1 day under the best concentration (0.05 mg·L^-1) treatment, compared with the control. After Robinia pseudoacacia seeds were treated with the best concentration(0.1 mg·L^-1) of natural brassinolide, the germination rate and germination energy of the seeds were increased by 10.9% and 15.9% respectively, and the mean germination speed of the seeds was cut down by 1.26 day, compared with the control. After hypocotyls of Pinus tabulaeformis and Robinia pseudoacacia were treated with the natural brassinolide, the elongation of their hypocotyls was obviously increased. 0.01 mg·L^-1 concentration of the natural brassinolide was the most suitable for the elongation of Pinus tabulaeformis hypocotyls,and 0.005 mg·L^-1 concentration was the best for the elongation of Robinia pseudoacacia hypocotyls.

The principal felling age of poplar on Changjiang River beach was studied in Nangen forest farm of Huaining County of Anhui Province. Based on beach altitude, the beach was divided into two site conditions: the higher beach(15～16.5 m) and lower beach(14～15 m). Model y=a+b lnA was selected as the growth model of poplar plantation. The yield table of poplar plantation was compiled by growth model. At the same time, the assortment yield table of poplar plantation was compiled based on the univariate volume ratio model. According to volume yield table and assortment yield table, the quantitative maturity age both two sites should be 7 years, technical maturity age of match blocks for higher beach and lower beach were 5 years and 6 years respectively. Economic maturity age was 10～13 years for higher beach(P=10%、8%、6%) and 11～12 years for lower beach (P=10%、8%) on the basis of the maximum net present value. In conclusion, according to the three maturity age and management purposes the principal felling age of poplar plantation should be 10～14 years for higher beach and 8～12 years for lower beach.

Baculum chongxinense chen et He has one generation every two years in Chongxin county, Gansu province. It overwinters as egg under the litter and in the soil. The egg diapause in the second year. It reproduces as parthenenesis. The larva has 3 instar. Each female laid about 40 eggs. The adult female feeds on the host voraciously. The use of Lindan smokes at the rate of 15 kg·hm^-2, Lindan dust at 30 kg·hm^-2, and 2.5% Gongfu EC or 2.5% Decis EC at 8 000～10000×or ultra low volume concentrates at 3?kg·hm^-2 for the control of the pest obtained over 90% mortality respectively.

To set up compensation system for ecological benefits of forest is important safeguard that can coordinate the benefit relationship between forest manager and person who benefit from environmental services function of forest,ensure funds for forest protection and management be firmly invested.By analyzing the problems confronted with study and practice in compensation system for ecological benefits of forest,author put forward that environmental reproduction is one of theoretical base of compensation system for ecological benefits of forest.The paper make systematic discussion about why compensation system for ecological benefits of forest should be made,how much funds should be compensated,who should supply with compensation funds and how to compensate.Meanwhile,the contents about how to use compensation funds,who should use funds and how to monitor the use of funds are also discussed.Finally,the overall train of though for directing study and practices be put forward.