Four treatments of Chinese Fir needle litter, Chinese Fir needle litter with addition of 2 g and 4 g NaNO₃ respestively, and Chinese Fir needle litter mixed with leaves from understorey plants were designed to investigate the effects of nutrient status on the decomposition rates and nutrient releases of Chinese Fir needle litter using the litter bag technique. The results showed that both adding NO^-₃-N and mixing with leaves from understorey plants to some extent accelerated the decomposition rate of Chinese Fir needle. The dry mass loss percentage, decomposition rate and half-life time of Chinese Fir needle were 20.49%, 0.001 6 per day and 1.2 a, respectively. Chinese Fir needle litter mixed with leaves from understorey plants had the highest decomposition rate with dry mass loss percentage of 43.67%, decomposition rate of 0.004 3 per day and half life time of 0.44 a. In the whole decomposition processes, there was a significant difference of decomposition rate between Chinese Fir needle litter mixed with leaves from understorey plants and Chinese Fir needle litter. The amount of NaNO₃ addition also affected the decomposition rate. Addition of 4 g NaNO₃ had higher decomposition rate with dry mass loss percentage of 42.07%, decomposition rate of 0.003 7 per day and half life time of 0.51 a than addition of 2 g NaNO₃ with dry mass loss percentage of 29.13%, decomposition rate of 0.002 2 per day and half life time of 0.86 a. The decomposition rate accelerations could be attributed to improvement in litter quality, in particular N content increase and C∶N ratio decline, because the relationship between the initial litter C∶N ratio and the proportion of dry mass remaining was significant. The N content in litter after NO^-₃-N addition and shrub leaves mixing had been increased as many 0.6～1.6 times as that in Chinese Fir needle litter. The reduction of C∶N ratios was 0.4～0.6 times. Nitrogen immobilization was observed in the decomposition processes of Chinese Fir needle while N mineralization followed by stabilization were found in the litter of treatments of NaNO₃ addition and mixing leaves from understorey plants. Understorey plants management and appropriate amount of NO^-₃-N fertilizer application would accelerate Chinese Fir needle litter decomposition and provide soil nutrient supply for plant growth.

Seedlings of five hardwood tree species, Castanopsis lamontii, Cyclobalanopsis myrsinaefolia, Castanopsis fissa, Castanopsis kawakamii, and Castanopsis sclerophylla were separately planted under 25-year-old Masson Pine plantation. After sixteen years following planting, the amount, nutrient contents and turnover time of forest litter were investigated in the above five types of mixed uneven-aged stands and pure Masson Pine forest. Results revealed that annual litterfall in the five mixed stands were 6 149.1, 7 533.2, 6 741.1, 7 151.5 and 8 041.7 kg·hm^-2 respectively, but only 3 442.8 kg·hm^-2 in pure Masson Pine stand. Binomial patterns was found for seasonal dynamics of litter in the mixed stands. The first peak occurred from February to April, the second occurred in August or September. Leaves account for 50%～71% of the total litter, branches 6%～26%, barks 9%～19%, fruits about 1%, and other components 5%～17%. In the mixed stands, 50%～58% of the total litterfall came from Masson Pine trees, 42%～50% from the respective hardwood trees, with significant difference existing between their litter composition. Nutrient concentrations of litterfall were different, with N ranging from 3.25～12.98、0.37～6.55、0.24～0.97、12.77～35.40 and My to 2.35～6.10 g·kg^-1. Total return of the five nutrient elements via litterfall for the six stands consistently decreased in the order: Ca>N>Mg>K>P. From annual litterfall the total return of five nutrient elements were 238.05, 213.77, 223.93, 289.90 and 304.12 kg·hm^-2 respectively, for the five mixed communities, and 142.01 kg·hm^-2 for pure Masson Pine stand. Litter accumulation in the forest floor in the five mixed stands were up to (8 448.0,) (15 565.8,) (11 993.7,) 12 718.6, and 6 974.2 kg·hm^-2 respectively, and 5 020.0 kg·hm^-2 for pure Masson Pine forest, with layer L making up of 47.2%, 59.6%, 51.3%, 61.0%, 85.4%, and 86.3% of the total respectively, averaged 61.7%. Significant differences in nutrient concentrations existed between forest communities and litter components, but the elements consistently revealed the same trend, decreasing in the order: Ca>N>Mg or K>P. Based on comparative analysis on litter accumulation and annual litterfall, the turnover time of litter in the six stands was estimated to be 1.15, 0.76, 1.42, 0.97, 1.17, 0.84 and 1.52 years respectively. Branches had longer turnover time than leafves. The branches and leaf from Masson Pine generally exhibited greater turnover time than that from the corresponding hardwood species interplanted under the pine canopy.

The research demonstrates variation and adaptive countermeasures of Quercus variabilis population through a discussion of its size, number of seedlings, characters differentiation and interior gene arrangement and offers the ecological strategies of Quercus variabilis population answering different habitats from mechanism. Both size and number of stump-sprouting vary from place to place seen from its distribution and the number of stump-sprouting is relatively less in Qinling distribution center, whereas almost every size class has a good few number of stump-sprouting on north slope of Bashan Mountain and Huanglong Mountain. These stump-sprouting offsets the shortage of seedlings, and help Q. variabilis population get through the pinch period thus regenerate themselves. At the same time, the branch length, ramification angle, ramification ratio, allele frequencies and differentiation coefficients of Q. variabilis population give birth to variance. From distribution center to margin, the branch length that every year diminishes while ramification angle and leaf obliquity takes on increscent trend, gradual ramification ratio R_1∶2, R_2∶3 and total ramification ratio R_b are also distinctly different. Gene variance frequencies of EST and SOD gradually diminish with that of POD gradually diminish along with age class augment, whereas the differentiation coefficients of EST, SOD, PGI, ACP and ADH wear increscent trend. These changes are adaptive response that Q. variabilis population reply to environments, and thereby, open out the ecological strategies and evolutional mechanism of Q. variabilis population.

This study investigated the carbohydrates and their metabolic enzymes to research the effects of acid precipitation (pH 6.0、4.0、3.0、2.0) and Al (theoretical concentrations were 75, 150 μmol·L^-1) on the sugar accumulation and transportation in Pinus massoniana with and without inoculating mycorrhizal fungus Pisolithus tinctorius. The results revealed that the acid precipitation and Al inhibited the chlorophyll and dry weights, between whom the great positive correlation (r=0.949) existed. The contents of soluble sugars decreased in leaves; the light acid precipitation induced sugar accumulation in the roots and stems, but the strong acid precipitation inhibited it; the acid precipitation and Al prevented the sugars transporting down to the roots. The trehalose accumulation was inhibited by the acid precipitation in mycorrhizal roots under the low Al stress, but it was induced under the high Al stress, which showed negative correlation with the activities of trehalase (r=-0.857). The light acid precipitation induced glucose accumulation in the roots, stems and leaves, but the strong acid precipitation inhibited it. The activities of glucose-6-phosphate dehydrogenase and trehalase were induced by the low Al stress, but they were obviously inhibited by the high Al stress. Inoculating mycorrhizal fungus at the roots induced the dry weights, prevented the sugars transforming into glucoses.

Four different kinds of water treatment were applied to compare the photosynthetic characteristics of Taxodium distichum and T. ascendens seedlings under simulation of soil water change of the hydro-fluctuation belt in the Three Gorges Reservoir Area. The aim was to shed light on the plants' physio-ecological adaptation to changing water levels for tree species selection and revegetation purposes. The water treatments were normal growth water condition (I.e. CK with soil water content being 60%～63% of soil water field capacity), light drought water stress condition (I.e. T₁ with soil water content being 47%～50% of soil water field capacity), soil water saturation condition (I.e. T₂ with soil water content being saturated) and soil submersion condition (I.e. T₃ with soil being submerged 1 cm). The results showed that the photosynthetic pigment content of T. distichum was significantly lower than that of T. ascendens both in T₂ and T₃. In CK, the seedlings of T. distichum did not differ from the seedlings of T. ascendens in net photosynthetic rate (P_n), transpiration rate (T_r), stomatal conductance (G_s), water use efficiency (WUE), apparent light use efficiency (LUE_app) or apparent CO₂ use efficiency (CUE_app). However, the seedlings of T. distichum had significantly lower P_n, lower LUE_app and lower CUE_app in T₂ as well as significantly higher G_s in T₃ than those of the T. ascendens seedlings in the same treatment. In T₁, the seedlings of both T. distichum and T. ascendens had significantly lower P_n, lower LUE_app and lower CUE_app than those of their respective other three treatments. The Tr and G_s of T. ascendens seedlings in T₁ did not differ from those of its CK, whereas the T_r and G_s of T. distichum seedlings in T₁ were significantly lower than those of its CK. The results verified that both T. distichum and T. ascendens took on features of water-tolerant and hydrophilic plants, which can be considered as two species to be chosen for the building of protection forest system of the hydro-fluctuation belt in the Three Gorges Reservoir Area. When compared with T. distichum seedlings, the T. ascendens seedlings have better capacity to tolerate water and drought stress, and can grow very well under soil water saturation.

A pair of primers were designed according to published Populus trichocarpa gene (PTD), and PtAP3, an AP3 homologous gene from P. tomentosa was isolated by PCR using genomic DNA of male clone of Populus tomentosa (L50) as template. The result indicated that the sequence was 1 813 bp (BamHⅠ and SacⅠ were introduced at the 5'and 3' end) including 7 exons and 6 introns, coding 238 amino acids. It was found to have 52%～82% homology to proteins from Lilium regale (AF503913), Petunia hybrida(AF230704), Gerbera hybrida (AJ009724), Rosa rugosa (AB055966), Malus domestica (AJ251116) and P. trichocarpa (AF057708) by blast analysis in GenBank. There was a highly conserved MADS-box motif in the protein of PtAP3, so it was putatived to be a transcription factor. The result of Southern blot analysis indicated that there were double copies of PtAP3 or two members which had a high homology to each other in P. tomentosa (L50, male) genomic DNA, and there was single copy PtAP3 in P.tomentosa (5082, female) genomic DNA. Sense and anti-sense expression vectors of PtAP3 were constructed by PCR and restriction enzymes digestion identification, and transformed into tobacco (Nicotiana tabacum) by Agrobacterium GV3101 and LBA4404. Some transgenic tobacco plantlets were obtained by PCR identification. The results above mentioned have provided important data to understand the molecular mechanism of male flower development of P.tomentosa, and also contributed to study on controlling flowering of P. tomentosa by gene engineering.

Variation of traits was analyzed included height, diameter at breast height (DBH), stem volume, crown width, straightness, wood basic density, tracheid length and width of open-pollinated progenies from clonal seed orchard of Pinus massoniana. Traits of growth, stem form and wood quality among families were significant differences that indicated the improvement potential was notable. Heritability of the height growth and wood basic density reached 0.691 and 0.640, respectively. According to the correlation analysis between traits, stem straightness could be improved indirectly when growth traits were improved, growth traits were significant correlated with wood basic density, and wood basic density was not significantly correlated with length and width of tracheid. Under the selection ratio of 10 percent, genetic gain was 19.74 and 19.32 percent respectively, and selected families from the progeny test stands at age of 5 years and 8 years were the same. And genetic correlation of height, DBH and stem volume was significant at level of 0.01. These all showed that selection of the short rotation of P. massoniana for pulp and paper use would be efficient for trees of 5-year-old. Comparing the heritability of all the traits and with the result of canonical correlation analysis, the trait of height growth could be the most important index for selection. Consideration was given to wood quality of all the families, and flowering and fruit setting of the clones in seed orchard, twelve plus families were selected under 10 percent selection ratio of height growth and stem volume.

The contents of 9 nutrient elements (N、P、K、Ca、Mg、Cu、Zn、Mn、SiO₂) in stem-flow, rainfall were measured in 4 tree species at 22～25-year-old grown in Zhuzhou, Hunan Province, such as Cinnamomum camphora、Liquidambar formosana、Eucommia ulmoides、Osmanthus fragrans from April of 2003 to July of 2004. The results showed that the content's of the nutrients in rainfall varied according to the month;the content sequence of the nutrient elements in precipitation were as follows: Ca>SiO₂>Zn>NH₄⁺-N>K>NO₃^--N>Fe>Mg>Mn>P>Cu; the content of the nutrients in stem-flow also varied in the same way and changed seasonally; compared with rainfall, most of them increased. The nutrient characteristics of stem-flow for different tree species were different significantly, the content sequence of the total nutrient elements in stem-flow was as follows: Liquidambar formosana、Eucommia ulmoides、Cinnamomum camphora、Osmanthus fragrans. The proportions of nutrient in stem-flow of different tree species also varied significantly, among all analysed nutrients, the content was found highest for K、Ca、NH₄⁺_N、SiO₂, middle for NO₃^--N、Mg、Mn、Zn, and lowest for Fe、P、Cu; the contents of Fe and Zn in stem-flow were lower than those in rainfall, significant variation was especially noted for Zn in the four tree species.

Based on investigation for three years, the medicinal plants in Changbai Mountain Notional Nature Reserve were studied first in the present paper. 613 species of medicinal plants belonging to 333 genera and 106 families, which accounted for 58.21%,69.66% and 88.21% of the total species, genera and families of wild medicinal plant resources in Jinlin Province respectively. Of which 39 rare and endangered medicinal plants accounted for 63.93% of the endangered medicinal plants in Changbai Mountain. 19 species of native medicinal plants in the northeast. 413 species of perennial herbs medicinal plants, which accounted for 67.37% of total medicinal plants in Nature Reserve. In this area, the medicinal plants of whole plant(herb),roots,and rhizomes used for medicinal materials accounted for 50.08%,16.48% and 12.89% of the total number of medicinal plants,respectively. 46.10% of species belonged to north temperate type. 94.29% of species distributed in Korean Pine broad-conifer mixed forests zone with an altitude of 720～(1 000 m). Dominant families were mainly Composiatae,Ranunculaceae,Rosaceae,and so on. Dominant genera were mainly Polygonum,Aconitum, and so on. The concrete suggestions of protection and exploitation were put forward.

Staghorn Sumac(Rhus typhina) is an alien tree species. It is a clonal woody plant with the distinguished characteristics, which the front part of the horizontal lateral root in the Staghorn Sumac is much bigger than the back part. In order to analyze the causes of the distinctive asymmetry of the lateral root diameter of the clonal ramets in Staghorn Sumac, samples were taken during the growth period in 2003.Nine individual plants at age of 1 year with their intact underground organs were carefully digged out and planted in the potters for feeding ¹⁴C isotope. The lateral roots of each individual plants at age from one to three or four were also taken for testing or observing in laboratory. Then the distribution of photosynthetic products in the clonal ramets were tested by means of isotope ¹⁴C tracer technique, the contents of hormone such as IAA,GA₃ and ABA of different organs in Staghorn Sumac were determined and the anatomical structure characteristics were observed. The experimental results showed that: 1)The abundances of isotope ¹⁴C in different organs of 9 clonal ramets of Staghorn Sumac were ranked as follows: feeding leaves>stem>the front part of the lateral root>the back part. 2) As the result of the higher density and larger diameter of vessel in the front part(RDF) of the lateral root of the clonal ramets, the abundant nutrition in the central part of the lateral root and the much numerous layer in the cambium, the width of the secondary xylem of the front part in the clonal ramets at age from 1 to 4 years was much larger than that of the back part(RDB). 3)IAA/GA₃ ratio of the front part in the clonal ramet at age of 1 and 3 was much higher than that of the back part. Therefore, it was concluded that the asymmetry of the lateral root diameter between the front part and the back part in Staghorn Sumac clonal ramet would be induced by the nonbalance accumulation of photosynthetic products, which accumulated in the front part of the lateral root of the clonal ramet much more than the back part, and related to the hormone level and the cambium activity closely. The stem of the clonal ramet and its front part of the lateral root would belong to the dominant and subdominant growth and the store center of photosynthetic products respectively.

The law of stump sprouting of broad-leaved tree species was studied in eastern forest area in Northeast China by the investigation of fixed sampling. The results revealed that the annual number of stump sprout of tree species was related to the diameter of stump obviously, it increased as the increase of stump diameter, then it decreased as the stump diameter increasing too large. According to the analysis on the relation between the number of stump sprout and the height of stump, the broad-leaved tree species in the study site were divided into three types of stump sprouting: the logarithmic increasing pattern, linear increasing pattern and exponential increasing pattern. The annual height growth of stump sprout was not related to the diameter and height of stump, but it was different in each tree species. Furthermore, the relationship between the number of stump sprout and the stump diameter in the second year was the same as that in the first year, and there were some stumps which could grow a few of new sprouts. The difference between the annual stump sprouting and biennial one was that certain number of sprouts were dead in the second year, and the number of dead sprout increased as the sprout number increasing of each stump. On the other hand, the rate of the stump with living sprouts was different in each tree species, the survival rate of Fraxinus mandshurica was 96.2%, Phellodendron amurense and Juglans mandshulica about 70%, maple(Acer spp.) 23.3%, and elm(Ulmus spp.) 21.8%. The investigation of selected-cut forest stand before 1990 proved that some stump sprouts of each tree species mentioned above could develop into big tree instead of the cut and fallen trunk.

The quadratic regression orthogonal design with five factors was adopted to shoot-used Dendrocalamus latiflorus forest planted on hills in Nanjing stated_owned forest farm. Results showed that the regression equation between fertilizer of N,P,K, organic fertilizer and shoot yield fitted very well, and that of N,P and shoots number fitted well too. The best fertilizing project was that N, P(₂O₅),K and peanut cake to be applied at 0.219 5,0.825 8,0.190 6,2.305 5 t5hm^-2 respectively. The fertilizing project for the highest yield was that N, P(₂O₅),K and peanut cake applied respectively at (0.218 6,) (0.826 2,)(0.189 9,) and (2.306 4) t5hm^-2.

Two theoretical-hypotheses were studied on forest ecological benefits compensation falsification. The economic activity with external economics needs to be compensated, the forest ecological benefits namely forest ecological value. The studies on the forest ecological benefits compensation lacks the supporting of essential theory. Forestry subsidization is the system designed by government for encouraging the silvicultural production to subsidize the silvicultural activities, its theoretical foundation is that interests are led, namely the factor of production flows to the trade of high rate of return on investment. Forest compensation is a measure of making up for a loss caused by government limit forest tree ownership of forest owner to perform for ecological safety, theoretical foundation are having right theory, fair burden theory, and specific sacrifice theory. Structuring system, of forestry subsidization and forest tree compensation so as to substitute the current forest ecological benefits compensation is a reform that suit the development of forestry production.

The climate of Hexi corridor is very dry, and the evaporation is 20 times of the precipitation. The earth being sandy causes continuously seepage loss and poor water protection, which leads to larger amount of water consumption in turf planting, high cost and poor_quality turf. In this region, the experiment of turf planting was conducted with the water_saving techniques, such as spray irrigation, film_bottomed tillage. Compared with the traditional water flood irrigation, it indicated that film_bottomed tillage irrigation can largely improve water_saving (only 1/3 of the water of the wild flooding irrigation). The film_bottomed tillage irrigation and spray irrigation were employed at the same time, only 1/4 of the water was needed in comparison with the flood irrigation. The quality of grassland planted by three measures was observed, including overlay degree, chlorophyll content, number of tillering, homogeneity, quality, disease_resistance, etc. Through evaluating the turf by using the correlative method of the Grey Systematic Theory, we found that the turf quality was the best with the film_bottomed tillage irrigation and spray irrigation combined. Although the technique of turf plant with film_bottomed tillage and water saving irrigation need much manpower investment for the first year, but the life of film is according to 15 years, this planting effect is much better than the general planting method, economical benefit is very prominent. From long run, this technique has more economical benefit, can save water 5 000 m³·hm^-2 per year, and establish the well foundation of water saving irrigation in the arid desert region.

The automatically classifying and identifying the TM remote sensing images of forest plays an important role in the monitoring and management of forest resources. In order to improve the performance of BP artificial neural network(BP ANN), many measures, such as standardizing input vectors, increasing verifying set volume, promoting training study algorithm, expanding layers of input-output and main factor analysis, were applied in the TM image data processing. Taking Wangqing Forestry Bureau of Jilin Province as the example study area, the authors studied the automatically classifying and identifying the TM remote sensing images of forest mixed with conifer and broadleaves using the improved BP ANN. The results show that accuracy of automatically classification and identification has been increased significantly, 19.14% higher than that of the traditional ANN method and 8.55% higher than that of traditional unsupervised classifying method respectively. The research also indicates that the classification and identification accuracy rate can be increased further with expanding the BP ANN network volume.

There are three different views regarding pathogenic mechanism of pinewood nematode disease: enzymes, cavitation, toxins.Most conclusions are based upon the change of the morphology of infected wood, but fail in expounding the internal mechanism on the molecular level. A immuno-cytochemical method for detecting BX (Bursaphelenchus xylophilus)antigen in pinewood section was established with anti-BX serum. The method not only showed a new potential for the direct detection of BX on pine wood section, but also discovered yield information about BX and nematode solvable antigen in wood tissues, and could be further confirmed synthetic matrices on pathogen distribution. Combining aspects of ELISA and immunoblot, the method was specific to nematode antigen two species of Bursaphelenchus genus, and could identify 0.1 μg nematode protein on the surface of pinewood section. With this method, it was detected that the BX antigen in tracheid tissue of Pinus thunbergii which were representative of a natural infestation.

In the dry substance of Parasarcophaga crassipalpis (PC) and Aldrichina grahami (AG), the protein contents were more than 60% in the maggots, and more than 70% in flies. The amount of essential amino acid [g·(100 g)^-1 protein] was between 46 and 59, higher than 35, the standard content of FAO/WHO. The ratios of the essential to total amino acid were higher than standard mode 40% of FAO/WHO. Among essential amino acids, all of the contents were higher than standard mode except Valine and Methionine plus Cysteine. The grease contents were around 20% in maggots, and less than 10% in flies. The ratios of unsaturated fatty acid to total fatty acid were more than 70% no matter in maggots or in flies. Essential fatty acid was Linoleic Acid, its contents were more than 40% in maggots and around 17% in flies. In PC and AG maggots, the contents of iron and zinc were opulent, the results of iron were 684 and 664 μg·g^-1 and the zinc were 170.5 and 158.0 μg·g^-1 respectively. The calcium contents were not more than perfect soybean, the amount were 0.46% and 0.48% respectively. The phosphorus contents were higher than normal milk powder, the amount were 0.57% and 0.54%. The ratios of calcium to phosphorus were 0.81 and 0.79 respectively, both higher than ideal value 0.5.

Forest fire is an important natural factor influencing the balance of atmospheric carbon in global change. In recent years, due to the human activities and some terrific climate events associated with global change, forest fires are aggravated day by day and effects global forest ecosystem. The influence of global climatic change from greenhouse gas included carbon from forest fires cause more attention. Based on the data of forest fire accounting from 1980 to 1999 and ground biomass estimation for some forest types in Heilongjiang Province, the amount of mean annual consumed biomass of forest was estimated to be {391 758.65～}522 344.95 t,about 6.4%～8.4% of total national consummation from forest fires, and the amount of carbon released to be 176 291.39～235 055.23 t, about 8% of total national emissions from forest fires. CO₂、CO、CH₄ and NMHC emission from forest fires every year in Heilongjiang Province were 581 761.6～775 682.25 t、34 892.275～46 523.04 t、(14 091.11～)18 788.15 t和6 500～9 000 t.

The rule of wind speed in the aweather area of the firebreak tree belt with three structures (sparse structure, tight structure and ventilate structure) was tested using simulating method in the wind tunnel experiment. The isogram of relative wind speed in the aweather area of firebreak tree belt with the three structures were drawn. Based on the feature of the wind speed, the forecasting models of wind speed in the aweather area of the firebreak tree belt had been established using the multi_model optimization. The results showed that the minimal relative wind speed in the windward area of firebreak tree belt with a sparse and tight structure was down to 70% below , but in the windward area of the ventilate structure was only down to about 80%. The sparse and tight structure had a better effect of shelterbelt than the ventilate structure in the windward area of the firebreak tree belt. The firebreak effect of the sparse structure was the best.

The significance of the effects of the protein level(crude protein,CP)and energy density(gross energy,GE) of the concentrated diets on the diets digestibility of four adult Giant Pandas was studied by grouping according to two-factors intersecting each other(2CP×2GE).The results indicated that the CP level of the concentrated diets had extremely significant effect on the digestibility of both crude protein and that of crude fat of the diets(P<0.01,positive corelation);the GE density had significant effect on the digestibility of crude protein of the diets(P<0.05,negative corelation);interacting effect of the two factors was significant on the digestibility of crude protein(P<0.05);the two factors & their interacting effect had no significant effect on the other kinds of digestibilities.By comparing every kind of digestibility of the diets(using LSR method) between different trials,formula 4 of concentrated diets(CP2×GE1,ie.CP20.61%×GE18.08 MJ·kg^-1) was the optimum formula.The research indicated that in general, some effects on diets digestibility for Giant Pandas were produced by CP and GE of the concentrated diets,and it seemed that adult Giant Pandas were inclined to concentrated diets with comparatively high protein and low energy.

It aimed at offering technique reference for studying the product line of wood strength's real time rating. It adopted the nature frequency measurement system of fast fourier transform(FFT) to auto_measure the dynamic modulus of elasticity(DMOE), and adopted mechanical test machine to measure the static modulus of elasticity(E_S) of air-drying lumber which were buying from the market. The species are including Fraxinus mandshurica, Pinus koraiensis, Juglans mandshurica. Some results were gained and described as follows: 1)The correlation between every species' E_S and transverse vibration DMOE(E_F), longitudinal vibration DMOE(E_L) are significant. 2)For whole species, the correlation between E_S and E_F, E_L are more significant than that the single sort of species'. It indicated that the method of FFT is universal. 3)The correlations between E_S and sample's density(ρ) are significant, but the correlation coefficient of E_S and ρ is lower those between E_F, E_L and E_S. It indicated that wood E_S is more exact by the method of estimating based on FFT measuring than the method of estimating based on density.

The thesis took wide belt sanders, belts four feet wide, two sides belts, model B229, made in China, as studying target. By means of the method of the framework dynamic design, beginning from its produced easily the horizontal lines defect to study its vibration characteristics and undertook respectively EMA (experimental modal analysis) and PSD(power spectrum density) to its sand shelf parts and whole machine etc. The modal test main takes cross spots testing method of fixed testing spots and alters the excitation vibration spots to result in its frequency response function of the fixed spots every excitation vibration spots, moreover applying SISO and taking advantage of frequency response function curve to modify completing mode parameter recognize so that getting its typical frequency response function chart of whole equipment and sand shelf part, as well as two classes mode shapes charts. It got sander's whole amplitude_frequency spectrums through PSD analysis and force frequency etc.

Wood flour/polypropylene composites were prepared by the special designed twin screw/single screw extruder system. The effect of EPDM-MA on water absorption, static and dynamic mechanical properties of wood flour (WF)/polypropylene (PP) composites were studied by static test, dynamic mechanical thermal analysis and scan electron microscope. The static mechanical properties of polypropylene/wood flour composites showed that the tensile strength and flexural strength were improved with the maleic anhydride modified ethylene propylene diene rubber (EPDM-MA), especially the impact strength of the composites was improved remarkably but decreased the composites' stiffness. The dynamic mechanical spectra of the composites showed that the storage modulus and tanδ peak values were decreased with increasing EPDM-MA loading. The reduction of the tanδ peak values revealed an improved interfacial adhesion between wood flour and polypropylene matrix. An increase in the main transition temperature implied the effect of EPDM-MA on thermal properties of composites. The second transition peak was also found from the spectra of DMTA about -50℃, which was especially in favor of improving impact properties. The scanning electron microscope study verifies an improved interfacial adhesion between wood flour and polypropylene matrix with EPDM-MA. EPDM-MA rubber domains were dispersed in the PP matrix, and the diameter of domains is between 0.1～1 μm. The water absorption of the composites was also decreased by EPDM-MA. EPDM-MA played a dual role, not only as a toughening agent but also as compatibilizer between wood and the polypropylene matrix.

This study was conducted for fully understanding of gutta-percha content characters in samaras from different variance-types, which as a result provided theoretical guidance for selections of valuable resources and effective utilization of Eucommia ulmoides. Typical sample-tree selection and random selection were applied and integrated extraction was used for the gutta-percha content rate test in this study. The result showed that there existed remarkable differences of samara's shape and size among four main variance-types. These differences of samara's configuration and size indicated the growth characters among variances. Furthermore, significant differences of gutta-percha content rate in both kernel and pericarp were observed among variance-types. The highest gum content in kernel and pericap was obtained from while forma crackle lowest from forma split.

In this paper, the 25 mm thickness Italian poplar thin board had been dried in the condition of comprehensive vapor drying technology with combination of high temperature drying and normal temperature drying technology in this experiment for more than one year. During preheated stage, the board was completely steamed, then changed to high temperature drying stage with over-heat steam in conventional pressure, the drying was continued till moisture content reached 25%, and then changed to normal temperature drying technology until the end of drying. The test results showed that the comprehensive vapor drying technology would not only shorten drying time, but also improve drying quality, as well as increase efficiency of produce.

Increasing carbon dioxide and other greenhouse gas concentration in atmosphere have resulted in global warming that threats sustainable development of human beings. International communities are taking action plans aiming to mitigate greenhouse gas emissions and to stabilize carbon dioxide concentration in the atmosphere. Forests and forestry activities play a significant role in these actions. Atmospheric carbon dioxide can be sequestered through tree growth and as a result forest ecosystems play as an important carbon pool and carbon sink in terrestrial and atmospheric carbon exchanges. Carbon sequestration by growing forests has been shown to be a cost-effective option for mitigation of global climatic change. On the other hand, deforestation, especially in the tropics, behind fossil fuel burning, was believed to be the second largest source of rising atmospheric CO₂ concentration. Therefore, such forestry activities as afforestation, reforestation, forest management, deforestation avoiding and so on are believed to be effective ways to enhance terrestrial carbon sinks and protect existing carbon pools. Wood products can also be used either directly as fuels or as substitutes for energy-consuming products (steel, cement, etc.) and at the end reduce greenhouse gas emission in energy production and industrial process. We reviewed global and China's forest ecosystems in relations to global carbon cycle, and discussed potentials of forestry activities in the mitigation of greenhouse gas emission.

Plant polyphenols, as one of the important natural products, widely exists in plants. It have been used in many traditional industries, such as leather-making, chemical engineering, medicine, agriculture, food and material. Especially in the recent years, the encouragement to environmental protection and green science accelerated plant polyphenols research and progress. In this paper, development trend and use prospect of this research field is summarized from its applications on traditional industry and fine chemicals utilizations industry.

It was researched that the numbers and biomass of soil microorganisms in different development stage of Chinese Fir plantation in Shanxia Farm of Sub-tropical Forestry Center, CAF in Fenyi Country, Jiangxi Province. The trend of the numbers and biomass of soil microorganism, the numbers of bacteria and the content of available N, P was decreased from juvenile to medium plantation, and increased from medium to mature plantation. But it was not found the trend from the numbers of fungi and actinomycetes, the content of available K,total N, P, K, in different development stage of Chinese Fir plantation.

Based on the whole stand model of Daqingshan, using simulation method, the impact of measurement error of number of trees per hectare, average diameter, dominant height, average height and form height on the whole stand model were studied. The result indicated that, beting estimated by least square method, basal area model, average diameter model, number of trees per hectare model had obvious biases, but dominant height model, average height model and form height model had no clear biases.

The physiological and anatomical changes in leaves of Poinsettia (Euphorbia pulcherrima) tube-plantlets occurred in the process of transplantation and acclimation were investigated in this paper. Before transplantation and acclimation, leaves of the tube_plantlets were apparently thin and the vascular system was not well developed, and the net photosynthetic rate of the plantlet was low, but the stomatal conductance and transpiration rate of the leaves were relatively high. At the early stage of transplantation, the tube-plantlet was vulnerable to relative low humidity and intense light that could resulted in wilting of leaves due to excess water loss. During the acclimatization, the net photosynthetic rate of the plantlets increased progressively and the stomatal conductance and transpiration rate decreased gradually, accompanied by an increase in the thickness of the leaves and the size of leaf epidermal cells, together with the fully development of vascular system, palisade and spongy tissues in leaves. The results indicated that the acclimatization could greatly improve the photoautotrophic ability of the tube-plantlets, bring anatomical changes to the plantlets in order to avoid excessive leaf dehydration for the gradual adaptation of the plantlets to natural environment.

The radiation energy environment, energy balance and water environment have been studied by means of the 3 treatments of covering plastic film, straw and planting Trifolium repens on the ground of Zanthoxylum bungeanum plantation in Feng County, Shaanxi. The results showed that the ground reflectivity and the canopy net radiation increased in the conditions of covering plastic film, straw and planting T. repens on the ground, so that the reflections in the middle part increased 53.3%,26.3% and 0.8% than that of the contrast. In the heat balance, the hidden heat flux in the conditions of covering plastic film, straw and planting T. repens accounts for 60.2%,62.4% and 65.8% of the net radiation energy, the reaction heat flux accounts for 30.4%,29.7% and 27.1%, and the soil heat flux accounts for 9.4%,7.9% and 7.1%. The soil water content in 0～50 cm were higher 5.6%,8.7% and 13.9% in covering plastic film, straw and planting T. repens on the ground than in the contrast. The transpiration rate of the leaves of Z. bungeanum were 1.6,1.4,1.1 times in planting T. repens,covering plastic film and straw on the ground as that of the contrast in May.

The aseptic seedlings of Albizia julibrissin were divided into two groups. One group was inoculated by rhizobia and the other was designed as control without inoculation. These two groups were all cultivated in sterilized cultured liquid for about two weeks. In the first group,the root hairs did not form on the main roots,but formed a lot on the base part of the lateral roots. In the second group, the root hairs did not form not only on the main roots but also on the lateral roots. The root segments which have distinctive deformation of root hairs from first group were cut off and fixed, in the meanwhile the corresponding root segments were cut off from the contrastive group and fixed. These two groups of roots segments were treated as semi-thin section and ultrathin sections, then were observed by optical microscope and transmission electron microscope. The result showed that the transfer cells with wall ingrowths on the tangential exowall of the root's epiderm and exodermis cells, are easy to be found in the root segments which has distinctive deformation of root hair. The wall ingrowth lies not only in root epidermal cells but also in the root exodermis cells, while there is no wall ingrowth in root epiderm and exodermis cells of A. julibrissin which is not inoculated by rhizobia. This suggested that the forming of root hairs and transfer cells in epiderm and exodermis of A. julibrissin is resulted from the inducement of rhizobia of A. julibrissin.

Rust of Sambucus williamsii and hyperparasite of the rust were found in Fengtong Zhai national nature sanctuary area. The pathogen was identified as Aecidium sambuci. The hyperparasite occurred on lower leaf surface rust spot. The characteristics of hyperparasitism was henna powdery. The hyperparasite live on aecium of A. sambucii and hinder the releasing of aeciospore. The hyperparasite was identified as Tuberculina sp.. This paper reported the symptom of the rust and the morphological characteristics of the rust pathogen. The hyperparasitism of A. sambuci and the morphological characteristics of the Tuberculina sp. Were also reported.

Wikstroemia chamedaphne was investigated for its acarocidal activity against Tetranychus viennensis, a serious pest of many crops including apple trees in China. Its active constitutes were extracted,separated and purified. The results indicated that the extraction of petroleum ether from WCME (Wikstroemia chamaedaphne methanol extract) appeared a strong acarocidal activity. The adjusted mortalities of egg,larva and female mite were 74.48%,100.00% and 100.00% respectively, while the LC_(50) values were 2.106 2、0.304 1 and 0.771 6 mg·mL^-1 respectively.

This paper investigates the possibility of measuring the surface roughness of wood by the laser displacement sensor. Ten points_based mean roughness of the planed surface of Douglas, Hinoki, Beech and Padauk was measured by using the laser displacement meter and the stylus instrument to clarify the characteristics of both instrument. The measured roughness from the laser displacement sensor at the processing speed of 6 m·min^-1 for forth wood specimens coincided with the value obtained from the stylus instrument by using a proportion coefficient between them.

The two methods of making rectangle_section curve woods were bending shape process or milling, which was analyzed in this paper. The difference of fibrin distributing and the variety of strength that caused were explained. The material mechanical theory was used to the numerical analysis of curve wood strength. The bending wood was stronger than milled curve wood,which was improved by the theory in this paper.With the curvature's increasing,the strength difference between them was greater.According to this theory,the strength difference of bending wood and milled wood was worked out by several parameters.In the application of curve wood,the theory of strength analysis was provided.

Growth quality of urban trees should include exterior growth quality, interior growth quality and anti-natural-calamity ability. To determine the whole growth quality of a tree, it is necessary to observe exterior characters of every part of the tree carefully. The hollows of the roots caused by decay or rot can be detected by Resistograph, and the hollows of the trunks can be detected by Resistograph and a stress wave meter.