To study the monthly dynamics of forest leaf litterfall, the leaf litters of 7 forests in Pingxiang of Guangxi were collected and their chemical components (N, P, K, Ca and Mg) were determined during the period from May of 2006 to April of 2007 The results indicated that the monthly variations of leaf litter's nutrient contents of N, P, K, Ca and Mg in leaf litters from seven standshad common trends. The contents of N and P in the leaf litterfall were high, while the content of K was low in the rain season (from April to September) when the temperature was high and trees grew vigorously. By contrast in the dry season (from October to next March) when the temperature was low and trees grew slowly or was in dormancy, the concentration of K was high, and the contents of N and P were low in the leaf litterfall. It suggested that N and P concentrations in the leaf litterfall were positively related to growth of tree, whereas the concentration of K in foliage litter was negatively related with the trees growth. The content of Ca was stable all the year within a forest, however it varied significantly from one stand to another. The monthly variation of Mg in leaf litterfall fluctuated significantly. The leaf litterfall's nutrient contents of different forests varied greatly. The highest content of N (14.44 g·kg^-1) occurred in Betula alnoides plantation and the lowest N (5.11 g·kg^-1) in Michelia macelureiplantation, the highest P (1.20 g·kg^-1) in the secondary natural forest and the lowest P (0.53 g·kg^-1) in Pinus massoniana plantation. Like to P, the highest of K was in the secondary natural forest with 5.16 g·kg^-1 and the lowest in Pinus massoniana plantation with 1.71 g·kg^-1. Ca of leaf litterfall in Cunninghamia lanceolata plantation was the highest (11.10g·kg^-1), and that in Pinus massoniana plantation was the lowest with 3.76 g·kg^-1. Mg of leaf litter fall in the secondary natural forest was 3.03 g·kg^-1 (highest), and that in Pinus massoniana plantation was 1.18 g·kg^-1 (lowest). Among the 7 experimental forests, the ratio of the highest content to the lowest content of every nutrient in the leaf litterfall was more than two.

The landscape pattern and dynamics in Beitun of Irtysh River Basin in Xinjiang from 1972 to 2000 were analyzed by using RS and GIS in integrating with the landform maps, vegetation maps and field investigations, based on the theory of landscape ecology. The remote sensing image data included MSS, TM, and ETM+. Quantitative indices of landscape pattern, including patch numbers, mean patch size, mean patch shape index, mean patch fractal dimension, Shannon diversity index, and Shannon evenness index, were chosen to analyze the landscape pattern changes. The results showed that desert was the matrix of the landscape inBeitun of Irtysh River Basin in the 28 years. During the period, the farmland area percent increased 9.62%, the desert area decreased 11.75%, the residence area increased 0.15%, the riparian forest area decreased 0.44%, and the wetland area decreased 1.06%. The landscape pattern analysis results showed, in the 28 years the patch number increased and the mean patch size decreased, which indicated that landscape in Beitun of Irtysh River Basin in 2000 was more fragmentized than the landscape in 1972. Up to 2000, the landscape in Beitun of Irtysh River Basin had many small patches. Both the mean patch shape index and mean patch fractal dimension index had a rise trend from 1972 to 2000, which showed that landscape patch shape was becoming more complex in Beitun of Irtysh River Basin. The Shannon diversity index behaved a rise trend from 1972 to 2000, which explained that the landscape heterogeneity decreased among the landscape types in Beitun of Irtysh River Basin. The Shannon evenness indexhad a similar trend, which showed that landscape types in Beitun of Irtysh River Basin distributed more evenly. Analysis of the transition matrix of landscape types in Beitun of Irtysh River Basin from 1972 to 2000 indicated that riparian forests were the most unstable type, and the main transition direction was grassland, secondly was farmland. The reason for riparian forest transferred to grassland and farmland would probably be due to the increased population and livestock numbers, the policy contradiction between graze and forestry management, extracting and intercepting water and so on.

In this study, growth and physiological adaptability of 18 plant species used in Cangnan alum mining tailings phytoremediation had been analyzed through ANOVA and subordinate function analysis. The results showed that there were highly significant differences in increase of the tiller height among three grasses, and in growth of the canopy diameter among woody plants. There were also highly significant differences in physiological indexes (including content of chlorophyll, activities of superoxide dismutase and catalase) among all different species. Different growth and physiological performance of different species reflected their adaptability variations on the alum mining tailings. The results also indicated that screening of plants would be an essential step for phytoremediation. Lespedeza formosa, Leucaena leucocephalacv. salvador, Broussonetia papyriferaand Vetiveria zizanioideshad been found as fitness pioneer species for alum mining tailings ecological restoration according to integration evaluation of the growth and the physiological properties. It would be beneficial to accumulate nitrogen and organic matter in tailing soil via planting Lespedeza formosa and Leucaena leucocephala which have capacity of biological nitrogen fixation.

In this study, a fulllength cDNA clone encoding GA20Oxwas isolated from the cDNA prepared from immature xylem zone of Populus simonii by the RTPCR method. The cDNA is 1 403 bp in length with an open reading frame (ORF) which is capable of encoding a protein of 385 AA. The deduced aa sequence of the PsGA20Oxproteins shares 66.0% and 57.0％ identity with those of Arabidopsis thaliana and Oryza sativa, respectively. Tissue differential expression indicated that PsGA20Ox transcripts had their mRNA products in stems, leaves and apical shoot meristems, with different abundant in them. The PsGA20Ox transcripts were the most abundant in mature xylem, followed by in the immaturity xylem and young leaf, and then in apical shoot meristems and the lowest transcripts were found in cambium. The genomic sequences of PsGA20Ox in 36 individuals were aligned, compared and analyzed using the software MEGA4.0 and DnaSP4.50 4. A total of 49 SNPs were detected and the frequency was 1/35 bp. Of the 49 SNPs, there were 15 common SNPs and 34 rare SNPs. There were 37 transition and 12 transversion mutation types. A total of 26 SNPs were detected in the coding regions of PsGA20Ox, of which 23 were silent mutations and 3 were missense mutations. The linkage disequilibrium of SNPs in the PsGA20Oxwas detected and the result showed that LD declined rapidly within the gene regions of PsGA20Ox with the nucleotide length. It suggests that in Populusgenome wide LD mapping may not be feasible and not be necessary, but candidate gene based LD mapping could be particularly useful in breeding programs of forest trees. The results, therefore, provided the important knowledge for the associated genetics of PsGA20Ox gene and the geneassisted breeding in terms of growth and development in P. simonii.

Genetic diversity of ten cultivars of Phyllostachys edulis and two affined species were investigated with 40 ACGM markers exploited from rice in this study. A total of 35 pairs of primers exhibited specific PCR products in at least one sample.Among those, 27 pairs of primers exhibited polymorphism PCR products in all samples, accounting for 67.5% of total primers. Eight pairs of primers had no polymorphism among all samples, and the sequences amplified with the same primer had little difference among randomly chosen five samples. Some genes, which were single copy in rice, exhibited multicopy in bamboo. The results of the cluster analysis showed that P. cv.Viridisulcata was closely related to P. cv. Luteosulcata, while P.cv. Tubaeformis had the fartherest relation to the other cultivars of P. edulis.

Amplified fragment length polymorphism (AFLP) analysis was used to reveal the relationships of species in Malus. A total of 72 samples representing 34 species, varieties, and hybrid species, and 38 cultivars were assayed. Six pairs of primer combinations selected from 64 combinations tested produced 1 692 legible loci, of which 1 547 (91.4%) were polymorphic. The genetic similarity coefficient among these 72 samples varied from 0.54 to 0.82. Four groups of taxa were assigned based on the results of cluster analysis with the genetic similarity coefficient at 0.60. First one was Malus florentina. The second contained the taxa of Sect. Choromeles. The third included the taxa of Sect. Docyniopsis. The taxa in Sect. Sorbomalus, Sect. Gymnomeles and Sect. Malusof Malus were clustered into the last group. All cultivars of apples and flowering crabapples distributed in the last group originated in Asia. The wild species in Asia played a very important role in the development of cultivars in Malus. A new section (Sect. Florentinae Cheng M. H.) was supported by the AFLP result. Sections of Sect. Sorbomalus and Sect. Gymnomeleswere suggested to merge into Sect. Malus (except Malus florentina) based on the results.

The physiological mechanism of bamboo aging was investigated by measuring endogenious phyto hormones, nutrients and C/N of the multched Phyllostachys violascens stands with different age. This study intended to develop a bamboo aging theory and find measures for improvment and rejuvinization of degraded bamboo stands. The results showed: 1) Bamboo aging promoted by multching was initiated in the rhizome, not involved in leaves. 2) Bamboo aging was regulated and controlled by the hormonal ratio of GA3/ABA, IAA/ABA, (GA3＋IAA)/ABA, i.e. bamboo aging was trigged when (GA3＋IAA)/ABA ratio declined below a threshold value, otherwise, the aging was prevented as its ratio was higher than a threshold value. In addition, GA3/ABA played a more important role than IAA/ABA in promoting senescence. Bamboo aging was involved in neither less synthesis of CTK in root, nor less upward transportation from root. CTK was not the hormone for inhibiting aging, and did not play role in aging inhibition. The results suggested the bamboo had a particular aging mechanism different with general plant, which may be attributed to its biological characteristics. 3) Bamboo aging was not caused by nutrient deficiency or rise of C/N, and rise of C/N was a result of hormonal regulation, but not a reason for the bamboo aging. The bamboo aging was regulated and controlled by hormones.

There were much hydroxybenzenes, polysaccharides, glucosides, flavone compounds found in flowers and the buds of Tilia amurensis, and proteins, coumarins and cardiac glycosides were also detected by systematically pretesting the chemical composition. In addition, tannins were found in buds. Hydroxybenzenes, polysaccharides, glucosides, flavones, coumarins and tannins were detected in fruits. The contents of soluble sugars, total phenolics and flavones in flowers and fruits of T. amurensis at different latitudes and elevations were investigated, and the results indicated that the contents of the three compositions varied with the latitude and elevation. Except total phenolics in flowers, the contents of other compositions in flowers and fruits decreased with increasing latitude and elevation. The content of soluble sugars in flowers was obvious higher than that in fruits, while other chemical composition contents were similar in flowers to that in fruits. By comparing the clustering analysis on the chemical compositions and genetic distance analysis of T. amurensis, we found that the variations of the content of chemical compositions were discontinuous at latitudes gradients while they are continuous at different elevation gradients.

Thermal dissipation probe (TDP) was applied to measure the sap flow dynamics of Robinia pseudoacacia in Ansai County in semi arid region of the Loess Plateau from April 26 to May 31, 2008. Soil water content, photosynthetic active radiation (PAR), air temperature, relative air humidity, water vapor pressure deficit (VPD) and wind speed were measured at the same time. The results showed that the leafflushing period in a R. pseudoacaciaplantation was divided into four stages: bud swollen, the beginning of leafflushing, the middle period of leaf flushing and the fully expanded leaf period. Sap flow velocity of R. pseudoacaciagradually increased along with the leaf flushing phenology and became stable untill the fullleaf period. Diurnal variation of sapflow velocity displayed a singlepeak curve with fastrising and slowdeclining trends, peak value in the full leaf period of leafflushing is about 0.002 7 cm·s^-1. Sap flow velocity was significantly correlated with PAR, air temperature, VPD and wind speed, and was negatively correlated with air relative humidity during the monitoring period. The correlation coefficients declined following an order of PAR, air temperature, VPD, relative humidity, and wind speed. Simple linear equations were tightly fitted with the variables of PAR and air temperature, and the regressive coefficients were highly significant. Soil water content was gradually declined around the leafflushing period, but its' influence on the sap flow was not significant. Diurnal variations of sap flow velocity for four individual trees had the same trend, and total water transpiration of each individual tree was correlated with its stem diameter. A close linear relationship was detected between total water consumption for transpiration of R. pseudoacacia tree and its diameter at breast height (DBH), which may be used to estimate total water consumption for transpiration of R. pseudoacacia plantation around the leafflushing period.

A 1∶50 000 scale aerial image of Chongming Island in 2005 was interpreted. GIS spatial analysis integrated with landscape pattern method were used to investigate community composition and structure of the coastal shelterbelts intending to comprehensively understand the structure and function heterogeneity with the calculation of completeness, pattern metrics and porosities. The result showed that completeness of the coastal shelterbelt in the Island was only 21% with obvious spatial heterogeneity. The completeness of the west and south coast was higher than those of the north and east part. Landscape metrics analysis disclosed that current shelterbelts were inconsecutive with small dispersedly distributing patches. The west and east coast had better continuity than the south and north part. Community structure and function investigation revealed that porosities of only a few plots can attain the optimum value, and wind breaking effect of the existing shelterbelts were poor. This paper proposed suggestions concerning quantity, structure and spatial distribution of future coastal shelterbelts construction, and also put forward the orientation of further research method and content in regard to coastal shelterbelts.

In the present study, life cycle and transmission of Guignardia mangiferae were determined by conventional isolation of endophytic fungi from asymptomatic leaves, withered leaves, cuttage seedlings, seeds and seedlings of various tea plants. The results showed that the highest isolation rate of G. mangiferae was found from species of Camellia sinensis, followed by C. oleifera and then C. japonica. There was also significant difference in G. mangiferaecolonization among various tea cultivars. In tea plants, the newlyflushed leaves were endophytefree. As the leaf was developing, colonization of G. mangiferaegradually increased, and the highest isolation rate of G. mangiferae reached to 73.5% in the mature. Isolation rate of G. mangiferae was also affected by other factors such as date of sprouting, harvest stages, temperature and precipitation. The low isolation rates of G. mangiferae were observed in spring, from February through June, whereas higher isolation rates were observed in May, July August and December. There was a temporal variation of endophytic G. mangiferaein leaves of tea plants in Fujian Province. G. mangiferae was not isolated from seeds and the newly germinated seedlings. With the seedlings developed, G. mangiferae colonized on the seedlings gradually. G. mangiferaecould grow out from the spores collected from the air in tea orchards. G. mangiferaecould transmit from mother stocks to cuttage seedlings, which showed a special pattern of vertical transmission. Based on these data, we suggest that G. mangiferae has two modes of transmission in tea plant orchards, horizontal transmission by ascospores and vertical transmission by mother stocks.

Effects of volatiles and their change of Larix gmeliniion the hostplant selection of a larch defoliator (Dendrolimus superans) were studied. The larch seedlings were treated by being cut, and the defoliator larva was feeding with 25% or 50% needles before bioassay experiments. The results showed that the mated female moths preferred to oviposite on healthy seedlings of Larix gmelinii, which accounted for 86.1%～89.5% of total eggs. Among different injuries, they preferred to oviposite on lightly injured plants, and the oviposition quantities were more on mechanically injured plants than on insect feeding plants. It was found that 92.4% eggs were laid on the ground and nets, and only 7.6% were deposited on plants after the female antennae were cut. The larvae tended to healthy plants rather than injured plants, which was consistent with the results of adult oviposition choice. β ocimene, myrcene and 3carene in the volatiles had repellent effects to femal adults, while camphene and phytol of 0.01, 0.1, 0.2, 0.5 μL·μL^－1 showed repellent effects to the males Besides, βpinene and S αpinene were attractive to both male and female adults in low concentrations, however showed repellent effect in high concentrations. Olfactory responses indicated that larvae were attracted by Rαpinene, phellandren, camphene and 3 carene, and repelled by myrcene.

The adults of Dastarcus helophoroideswere reared in grooves of wood blocks, and their eggs were preserved at 5 ℃ to maintain the egg viabilities of D. helophoroides. This study observed the behavior and parasitical rates of newly hatched larvae of D. helophoroides to larvae of Anoplophora glabripennis, and compared the control effect to A. glabripennis between releasing D. helophoroideseggs in forests and injecting a pesticide, Omethoate, in trunks. The results showed hatching rates of D. helophoroides eggs preserved in low temperature for 49 d had no difference from those of newly laid eggs. First instars larva of D. helophoroides survived 1～8 d in laboratory, with an average of 2.26 d.Crawling speed of a larva was 65～100 cm·h^－1, on average of 2523 cm·h^－1. Newly hatched larvae released in both laboratory and forest could find and parasitize their hosts. With proper temperature and humidity environment, the parasitical rate could reach 90% if releasing 15～20 D. helophoroideseggs per one A. glabripennis larvaThe population of A. glabripennis declined more than 85% after both releasing eggs of D. helophoroides in forests and injecting the pesticide in trucks. It was proved there was no difference in control effect to A. glabripennis between the two methods.

The defense response of hemolymph in the larvae of Apriona germari to Beauveria　bassianawere studied. The result showed that the kind and number of hemocytes in control Apriona germari larvae were stable, while Beauveria bassiana conidia had significant impact on the number of the hemocytes in Apriona germari larvae. The total number of hemocytes did not change significantly within the 1stday after inoculation. It increased gradually after one day, and reached to maximum in two and half days after inoculation. Then it decreased gradually to the lowest level. The counts of Plasmatocyte and Granulocyte of the hemocytes in the infected Apriona germari larvae showed similar pattern.

The insect community structure and temporalspatial niche of dominant species in a peach orchard were investigated in Beijing suburb. The results showed that the insect community was abundant, which including 9 order, 25 families, 34 species, and the dominant species were Carposina niponensis, Pseudaula caspis pentagona, Dichocrocis punctiferalis, Lyonetia clerkella, Pseudaulacaspis pentagona, Myzus persicae, Orius sauteri, Leis axyridis, Epistrophe balteata, Chrysopa phyllochroma and Chilocorus rubidus. The species number, individuals of species, diversity indices, and evenness changed with time. In pest subcommunity, the niche breadth of Pseudaulacaspis pentagona was the biggest, successively followed by Myzus persicae, Lyonetia clerkella, Pseudaulacaspis pentagona, Dichocrocis punctiferalis and Carposina niponensis. In natural enemies subcommunity the niche breadth of Chilocorus rubidus was the biggest, successively followed by Leis axyridis, Epistrophe balteata, Chrysopa Phyllochroma, Orius sauteri. The niche of Chilocorus rubidusoverlapped with insect pests more than that of other natural enemies did with insect pests, and the synchrony in temporal dimension and similarity in spatial dimension between Chilocorus rubidus and Pseudaulacaspis pentagonawere better than other enemy insects. The results indicated that these natural enemies populations should be protected and utilized to control pests in peach orchards.

In the 35 diferent Pestalotia funerea strains，the toxicity of metabolic substances of the strain PF-11 (from Pinus tabulaeformis) was the highest，and that of strain PF-2 (from P. massoniana) was second. Using PF-11 as original strain，ten mutants were obtained by 3 continuous times under ultraviolet muta genesis dosage which was less than lethal dosage. Three active fractions with the Rf values of 0.83，0.79，0.80 were separated from P11 metabolic substances by gel H60 column chromatography with nbutanol∶methanol∶water (4∶1∶2) as the mobile phase．Four active fractions with the Rf values of 0.83，0.79，0.80，0.60 were purified from the ultraviolet mutant of P11-4，which showed one more active fraction was produced affer treated with ultraviolet. The formula was C₁₂H₂₃O₉N(M r=325) with the structure of O O O NHCH₂CH₂CH₃indentified by IR，MS and 1HNMR. The ultraviolet mutant were used to investigate their weeding effect, and the results showed that three mutants were negative with no toxicity to objective weed； five mutatants didnt increased obviously on toxicity； however PF11-4 and PF11-6, were positive mutants and their toxicity against objective weed were increased obviously.

Resonance board is an important component of piano，which predominates the acoustical quality of piano. This study attempts to establish a relationship between the vibration properties of resonance board and the acoustical quality of piano. The vibration properties of the two resonance boards made from each species of Picea glehnii，P. jezoensis，P. spinlosa and P. sitchensis were measured by analyzing the resonance spectrum based on FFT. The modules of elasticity (MOE)，velocity of longitudinal wave (V L) of resonance board，the MOE of samples cut from the edge of the resonance board and the response time for vibration of soundboard of piano were calculated. Then the resonance boards were made to pianos，and piano experts evaluated their acoustical qualities. The results showed that it possesses a significant correlation between subjective evaluation and the experimental vibration properties of resonance board in the y direction，but insignificant in the x direction. That may be explained on the fact that the strings in high and intermediate frequency region array nearly parallel to y direction，and that the angle between strings in low frequency region and y direction is smaller than that between strings and xdirection of the soundboard. It suggests that the acoustical quality of piano may be bettered by improving the vibration properties in y direction of resonance board.

Bamboo carbons were prepared by bamboo butt，bamboo burl and bamboo branch，then the bamboo activated carbons were prepared by bamboo carbons at 700 ℃ under different concentration of KOH solution by using KOH as activator，the adsorption of bamboo activated carbon with best adsorption capability to phenol was measured at different time and solution concentration，and the structure of different carbon was also characterized. The results show that the bamboo activated carbon has best adsorption capability to phenol when the concentration of KOH solution is 16.0 g·L^-1，and the bamboo butt activated carbon has best adsorption capability to phenol among the bamboo activated carbons prepared by butt，burl and branch respectively. The adsorption of bamboo butt activated carbon to phenol can reach to equilibrium when the adsorption time is within 40 min，and the adsorption capacity of bamboo butt activated carbon to phenol reaches to 83.4 mg·g^-1 which tend to saturation at 30 ℃. The porosity rate of bamboo butt carbon，bamboo burl carbon and bamboo branch carbon is 0.656，0.698 and 0.740 respectively，and the porosity rate of bamboo butt activated carbon，bamboo burl activated carbon and bamboo branch activated carbon is 0.688，0.748 and 0.790 respectively. The specific surface area of bamboo butt carbon and bamboo butt activated carbon is 110.4 and 475.7 m²·g^-1 respectively，and the pore volume is 0.09 and 0.26 mL·g^-1 respectively，the average pore size is 3.16 and 2.19 nm respectively.

Chinese Fir (Cunninghamia lanceolata) wood powder from agriculture and forest waste was pyrolyzed in onestep carbonization process and two step heating carbonization process at 900 ℃．The study indicated that onestep heating and two step heating carbonization process could enhance the micropore and mesopore of wood charcoal．With the analysis of the N₂ adsorption isotherm，both one step process and two step process were good for improving the specific surface area of wood charcoal, and the two techniques were good for developing the total pore volume，the value was 0.561 and 0.784 mL·g^-1 respectively, both the pore radius were concentrated on 0.6～2.0 nm．As a whole，the two step process was better than one step process．With the optimized techniques process，the specific surface area，the total pore volume，the iodine value of two step process was 1 288.4 m²·g^-1，0.784 mL·g^-1，1 038.2 mg·g^-1，respectively. As the result of XRD and Raman，two step heating carbonization process was more benefitcial than onestep heating carbonization process．

Logistic models were developed to explain investment on afforestation and management, and on developing understory economy respectively through a survey of 195 contract households participating in national forest property right system reform in Yichun city of Heilongjiang Province. Based on the two models, the key factors influencing subsequent management behavior of contract households were analyzed. The results showed that policy of forest right certification, site grade of forestland and regional dummy variable had significant influence on investment on afforestation and management, and on developing understory economy, and policy of forest management scheme and forestland rent, education level of householders, and familys monthearning had significant influence on investment on afforestation and management from contract householders while policy of cutting quota, distance from home to forestland, forestland area, sex and extra job of householders and timber production of forestry bureau had significant influence on investment on developing understory economy from contract householders. According to the results of regression analysis, a few suggestions were put forward. First, policies related to national forest property right system reform should be improved in time. Second, developing understory economy needs more support from government. Third, more attention should be paid by government to the comparison between the policy of charging forestland rent and exempting agricultural tax for contract householders.

The forest ecosystem services evaluation is one of the hot spots on forest ecosystem research. We assessed the quantity value and the economic value of Chinese Fir (Cunninghamia lanceolata) forest ecosystem services on the basis of the longterm observation of several ecosystem research stations which belonged to the chinese forest ecosystem research network（CFERN）, the data of forest resource in China and the data of social commonality. The research was carried out in three aspects （provide air anion, absorb pollutants and the dust catching property）. The results showed that the total economic value of Chinese Fir forest ecosystem in 1994—1998 and 1999—2003 respectively are 15 643.82×10.8yuan·a^-1 and 17 043.86×10.8yuan·a^-1, the unit area quantity value respectively are 12.62×10.4 yuan·hm^-2a^-1 and 12.34×10.4 yuan·hm^-2a^-1 The sequence of the six services which we assessed is water supply > nutrition storage > carbon fixed and oxygen released > biodiversity conservation > atmosphere environmental purification > soil conservation.

This paper described the problem of growth and yield model anciently and the meaning of mixed effects models in forest growth model. The expressive forms and arithmetic of linear mixed effects models and nonlinear mixed effects models was introduced separately. The study's evolve of mixed effects models about the height, the basal area and tree volume is reviewed in detail. The problem and research foreground of the future was pointed out.

There are abundant genetic resources of poplars in southwest China, which is believed as a centre of Sect. Tacamahaca natural distribution and evolution. The resources have played an important role in the poplar researches and application. However the resources are not well known by the rest of the world, and their value has not drawn enough attention of most poplar researchers. There are 28 species, 22 varieties, and about 10 natural hybrids of genus Populus in the region. Among them, 25 species are endemic in China, and 18 species are indigenous in southwest China. Although there have been many studies on the classification of Populus, some contradictions still exist. The genetic diversity of P. cathayana and P. yunnanensis was determined by molecular markers, while the other species have not been involved in this kind of study. The native poplars are grown extensively to provide timber, fuel and forage, and to protect the agricultural fields, grazing lands, cities, villages and houses along roads and channels, but the lack of improved variety and cultivation technique has limited the development of poplar plantation. On genetic improvement, only a few works such as selection of superior trees was sporadically carried out, and no breeding achievement was reported in the past. At present, there is no effectivemeasure to conserve the native poplar, and the genetic resource has been facing severe damage from extensively economic construction, especially hydropower exploitation. Therefore, more attention and support are needed from the local government for the conservation, application and research on the poplar resources.

Water holding capacity, absorption rate and saturated water stock of a different forest’s floor were studied in Liu Pan Mountain. The results showed that at the beginning of dipping in water, the absorption rate was high, and then it leveled off with the time going on. Undecomposed litter and halfdecomposed litter were saturated with water in 2 and 4 h, respectively. Except Pinus tabulaeformis litter, water holding capacity of halfdecomposed layer was 3.5 to 8 times as the dried weight and the water holding capacity of halfdecomposed layer was 1.8 to 7.6 as the dried weight. The water holding capacity of broadleaved litter was greater more than that of needle litter, and the capacity of moss was greater than branch litter. The water absorption rate was regressed to the time with the equation of Y＝a+bt^-1. Litter saturated water reflects hydrologic function. Litter saturated water Larix principisrupprechtii and Quercus Liaotungensis were larger than other species in the valley. Additionally, there was abundant grass stock in Larix principisrupprechtii and Betula platyphylla forest, and the grass water stock was respectively 5.4 t·hm^-2, 3.9 t·hm^-2, which accounted for 9.3% and 12.0% of that of litter in the two forests.

Pre column derivation of and high performance liquid chromatography (HPLC) with ultraviolet detection were used to detect the epurated artemisinin in Artemisia annua, and the artemisinin content and biomass yield were compared between the introduced A. annuaand the local wild A. annua. The result showed that the quantity of artemisinin was mainly affected by the genetic background, and secondly influenced by the environment and climate of the cultivated region. The seedlings raised with the integrated platetype paper containers method in greenhouse had longer growth period of A. annua by about 45 days in frigid area. The highest content of artemisinin was 0.555% and the highest biomass yield was (3 526.7±378) kg·hm^-2. High artemisinin content and biomass yield together contributed to artimisinin production. The introduced cultivars had a strong capacity to quickly adapt to the circumstance in Heilongjiang. The artemisinin contents reached to the purchasing level. The mean biomass of individual plant was greater than that in its original region.

The article investigated the changes of nutrients (total sugar, total nitrogen, total sugar/total N) and oxidases (IAAO, POD, PPO) of Catalpa bungeicl. ‘Yu1' in the cutting rooting process. The results showed that: C. bungei cl. ‘Yu1' cutting rooting initiated from the lenticel .The soluble protein in the forcedsprouting cuttings decreased dramatically in the early stage, and then the decrease tended to slow. The total sugar content slowly increased throughout. The total nitrogen had a little change. The total sugar/total nitrogen ratio had same trend with total sugar. The IAAO, PPO activity of the forcedsprouting cuttings showed up down up down pattern in the rooting process, The POD activity rose in undulation pattern. The role of three oxidases was both independent with each other, and related to one another in the process of rooting by which affected rooting in integration.

Gas exchange, chlorophyll a fluorescence kinetics, chloroplast pigments and spectral reflectance were investigated to explore the variations of photosynthetic capacity, primary photochemical reactions and development of photoprotective mechanisms in chestnut leaves from emergence to full expansion under field conditions. The results showed that during leaf development, net photosynthetic rate (P_n) gradually increased. Although the maximum quantum yield of PSII photochemistry (φPo) was quite high at the initial stages of leaf development, P _F was markedly lower than that in fully expanded leaves. When the relative leaf area (RLA) was about 10%, φPo and electron transport per active reaction centers (ETO/RC) were just a little lower than that in fully expanded leaves, indicating that its primary photochemical capability had been nearly completed. Due to low chlorophyll concentration, absorption flux per excited crosssection (ABS/CS) in a young leaf was less，nevertheless the absorption flux per reaction center (ABS/RC) was more than that in a mature leaf because of lower density of reaction centers (RC/CS) in the young leaf. High ABS/RC as well as low Pnresulted in more heat dissipation per reaction center (DI O/RC).The changes of chlorophyll were in opposition to the deepoxidating degree of xanthophyll cycle pigments (ΔPRI) at various expanding stages of leaf. The content of chlorophyll per leaf area (ChlNDI) increased steadily with the progress of leaf expansion. When exposed to high irradiance at midday, the deepoxidation of xanthophyll cycle pigments in newly developing leaves was considerably enhanced compared with fully expanded ones, which indicated that xanthophyll cycle might play a key role in excessive energy dissipation in young chestnut leaves. Anthocyanin accumulation was observed in newly emerging leaves of chestnut. The foliage was not photostable and was vulnearable to photodamage because levels of light utilization and its capacity to dissipate excess energy were low. Above results implied that anthocyanins could protect newlyemerging leaves against high light stress, which could interprey why the deepoxidating degree of xanthophyll cycle pigments (ΔPRI) at 10% RLA leaves was appreciably lower than that of 30% RLA leaves. We propose that the timely development of the above photoprotective mechanisms in young leaves is a reason of protecting their photosynthetic apparatus from photodestruction.

This paper compared chemical constituents and antimicrobial activity of the volatile oil from Solidago canadensis and S. decurrens. The volatile oils were respectively obtained from fresh leaves of the two species with hydrodistillation. S. canadensis a newly extended invasive species in east China and S. decurren is a traditional Chinese medical plant in wild. Major chemical constituents of the volatile oil were identified and analyzed by GC MS analyses. Antimicrobial activity was tested by the disc diffusion method. The results exhibited that the greatest component of the volatile oil from leaves of S. canadensis was germacrene D(44.24%). The greatest component of the volatile oil from leaves of S. decurrens was δelemene(21.73%). High content of a component acted as anticancer activity in the oil from S. decurrens was detected. The antibacterial activity of the volatile oil from S. canadensis was lower than that from S. decurrens. Chemical constituents of the volatile oil from S. canadensiswere obviously different from that of the volatile oil from S. decurrens.The volatile oil from S. canadensiscould not replace the volatile oil from S. decurrenson values of medicines.