This research examined monthly dynamics of soil respiration and their relationships with soil temperature at 5 cm depth (using Lci Portable Photosynthesis System (SRS-1000)) and seasonal variations of fine root (<2 mm) biomass in 0～50 cm depth (soil core method) in an age series (1～6-year-old) of Eucalyptus grandis. The results showed that monthly (early month) soil respiration rate (SRR) ranged from 0.35 to 1.71 μmol·m^-2 s^-1, and the seasonal values were different as following descending sequence: summer (1.55), autumn (1.16), spring (0.62), winter (0.41 μmol·m^-2 s^-1) (P<0.01), and in different ages showed that 6-year-old (1.10)>5(0.99)>2(0.93)>1 (0.82)>3(0.80)>4(0.67 μmol·m^-2 s^-1) (P<0.01). The relationship between early monthly dynamics of SRR and soil temperature at 5 cm depth was significant (R²=0.706 3～0.965 7, P<0.05). The exponential equation of R_s=a·e^(b·T) and Q₁₀=e^{10b were applied to search the relationships of monthly soil temperature at 5 cm depth and SRR, and the temperature sensitivity (Q₁₀) was from 1.73 to 2.29. The binary linear regression between soil temperature at 5 cm depth, fine root (<2 mm) biomass in 0～50 cm depth and SRR is significant (P<0.01).}

Carbon storages and distribution in three patterns of poplar-crop intercropping patterns were studied with a biomass measurement method in the North of Jiangsu Province. The results indicated that total soil carbon in 100 cm ranged from 0.64 to 15.27 g·kg^-1. For the three patterns, soil carbon storage of K, P and W patterns was 71.19, 40.67 and 42.64 t·hm^-2 respectively. There was a significant difference in carbon density between fine roots and other components of the poplar, but carbon storage in poplar stem ranked first compared with other poplar components. Carbon density in roots of corps was significantly lower than that of other components of the crops investigated, and the carbon storage in the harvested parts (ears or pods) was higher than that of the other parts, accounting for about around 50% for wheat, maize and bean, while around 45% for rice. However, the highest carbon storage of the crops was observed in the annual cropping system of wheat+corn among three poplar intercropping patterns. The annual carbon return in litterfall was (0.78±0.23)，(0.73±0.22) and (0.37±0.09)t·hm^-2a^-1 respectively for K, W and P pattern. Carbon storage in poplar-crop intercropping ecosystem for the three patterns was in an order of K pattern＞W pattern＞ P pattern, while the carbon storage in the various parts of the agroforestry system was soil＞crop＞poplar＞litterfall for all the three poplar-crop intercropping patterns.

The paper studied the application of reduced glutathione(GSH) in increasing the chilling resistance of young loquat(Eriobotrya japonica cv. Zaozhong No.6) fruits. The container seedling of three-year-old loquat were treated with 100, 300 and 500 mg·L^-1 of GSH to investigate the effects of exogenous GSH on AsA-GSH circulation metabolism in chloroplasts of young loquat fruits under low temperature stress, and its effects on the resistance to low temperature stress. The results showed that the contents of reduced glutathione(GSH) and ascorbic acid(AsA) in chloroplasts decreased and the activities of ascorbate peroxidase(APX, EC 1.11.1.11), glutathione reductase(GR, EC 1.6.4.2), dehydroascorbate reductase(DHAR, EC 1.8.5.1) and monodehydroascorbate reductase (MDHAR, EC 1.6.5.4) were also inhibited decreased when the young loquat fruits were under low temperature stress. The treatment with 100 mg·L^-1 of GSH on young loquat fruits could significantly increase the GSH, AsA contents and APX, GR, MDHAR activities. Furthermore, the treatment promoted AsA-GSH circulation metabolism, and improved the ability of free radicals to scavenge in chloroplasts. The results demonstrated that exogenous GSH played a role in the low temperature stress resistance of young loquat fruits.

Growth of pollen tube and style physiology characteristic index after pollination were studied for Self-compatible apple cultivar ‘Zaohongxiang' and self-incompatible apple cultivars ‘Dounan', ‘Fuji', ‘Golden Delicious'. The results showed that: pollen tube grew normally and entered into the style base after self-pollination of self-compatible cultivar and cross-pollination of self-incompatible cultivar. Self-pollination pollen tube of self-incompatible cultivars grew normally after self-pollination within 24 h and stopped growing after 48～72 h when the pollen tube reached the 1/2 of the style to stigma. The style SOD, POD and CAT activities of self-compatible cultivar ‘Zaohongxiang' were relatively stable within 48 h after self-pollination. The SOD, POD, CAT activities and MDA content of self-incompatible cultivars had great changes after self-pollination 24～72 h when the pollen tube stopped growing. Style GA3 content of self-compatible cultivar ‘Zaohongxiang' had a peak and the ABA decreased in 24 h after self-pollination. Style ABA content of self-incompatible cultivars increased significantly after self-pollination 12～48 h. The（IAA+GA3）/ABA ratio sharply increased at 12～24 h after self-pollination and then decreased in ‘Zaohongxiang', but it still was higher than that of self-in compatible cultivars.

A method combining on microwave sample digestion and inductively coupled plasma-mass spectrometry (ICP-MS) detection was established for determining of multiply inorganic elements in Bamboo leaves. Determination limits of 19 elements were in a range of 0.001～0.30 μg·g^-1, coefficients of variation (CV) were in a range of 2.19%～7.30%, and the recoveries of elements were in a range of 80.7%～122.4%. The results indicated that the method is simple, rapid, sensitive and accurate, and can meet the demand for 18 elements analysis in bamboo leaves. Ca, Mg, Fe, Al, Mn is relative abundant in the bamboo leaves.

Amplified fragment length polymorphism (AFLP) was used to study DNA diversity of 16 species in Indocalamus and other 5 similar bamboo species. Genomic DNA was digested with EcoRⅠ and MseⅠ enzymes and amplified with 9 (EcoRⅠ+3)／(MseⅠ+3)　primer combinations. In the 21 samples, 9 EcoRⅠ-MseⅠ AFLP primer combinations produced 1 367 legible bands, of which there were 115 common bands, 273 specific bands and 72 specific missing bands. In the 16 samples of Indocalamus, 1 193 legible bands were obtained by using 9 primer combinations，with 190 common bands, 177 specific bands and 98 specific missing bands. All the specific bands and specific missing bands would be used as molecular markers to identify these species. The AFLP markers indicated that I. Migoi and I. Latifolius were the same species.

Five Chinese White Pear (Pyrus bretschneideri) cultivars， with known S-genotypes， were used in this study. The genomic DNAs were extracted and amplified by PCR with three pairs of primers corresponding to pear SFBB-alpha, SFBB-beta and SFBB-gamma genes, respectively. Results showed that only one primer pair PSFBG-F/PSFBG-R successfully amplified a fragment of approximately 1 300 bp from ‘Jinhua’ (S₁₃S₁₈)，‘Jinhuasihao’ (S₁₃S₁₈) and ‘Eli’ (S₁₃S₃₄) corresponding to pear SFBB-gamma gene. This gene was named PbSFBB13-gamma (Pyrus bretschneideri SFBB13-gamma) and deposited under GenBank accession No. EU081892. RT-PCR revealed that the PbSFBB13-gamma was expressed specifically in the pollen grains. The coding region of the PbSFBB13-gamma was 1 191 bp in length encoding 396 amino acids with a predicted molecular weight of 45.4 ku and isoeletric point of 4.63. The SFBB13-gamma displayed the typical structural characterization of SFB/SLF genes, I.e. an F-box motif and four variable regions. At the deduced amino acid level, it shared 17.8% to 97.7% similarities with other SFB/SLFs of rosaceous plants. These characteristics of PbSFBB13-gamma fully demonstrate that it is a candidate of pollen S-gene although its function in gametophytic self-incompatibility (GSI) response is not confirmed yet. Phylogenetic analysis revealed that 34 rosaceous SFB/SLFs were dived into two subfamily-specific groups, but did not further form species-specific subgroup. The evolutionary pattern of SFB/SLFs concurs with that of rosaceous S-Rnases, suggesting that SFB/SLFs occur after divergence of subfamily but before the divergence of species as S-Rnases do in Rosaceae. The present study could provide a scientific base for fully clarifying the mechanism of pear GSI at the molecular level.

Genotypes of six natural populations of Sorbus pohuashanensis were studied using horizontal starch gel electrophoresis and the mating system was analysed at eight loci(Pgm-1, Pgm-2, Pgm-3, Pgi-1, Pgi-2, Pgd-1, Pgd-2, Pgd-3) using MLT software. Results indicated that the gametes ratio of each locus in pollen and ovule pools was mainly in balance in the six populations. The multi-locus outcrossing rates were above 0.981. The margin of multi-locus minus single-locus outcrossing rate(t_m-t_s) showed that slight inbreeding existed in the populations. Therefore, the mating system of S. pohuashanensis in the 6 populations is predominantly outcrossing. The inferred inbreeding depression(δ=1) from the electrophoresis data indicated severe inbreeding depression in the natural populations of the species.

Seeds of Picea asperata were dried from 82 g·kg^-1 to 64，52，41 and 29 g·kg^-1 moisture content in a desiccator with silica gel. After the desiccation, seed vigor and physiological indices, including seed germination energy, germination percentage, germination index, relative conductivity, dehydrogenase activity and isocitrate lyase activity were measured. The results showed that the seeds had high desiccation tolerance.When dried to 41 g·kg^-1，the seeds still had stable viability，the relatively integral cell membrane structure，the high dehydrogenase and isocitrate lyase activities.To some extent, the seed kept genetic stability by artificial aging test.

This study was conducted in a small watershed of Huodigou, which is a part of natural forest region located at a medium altitude on the south-facing slopes of the Qinling Mountains. Water samples were collected from rainfall, throughfall, litter drainage, subsurface flow, stream water in the tributaries within the watershed, and flow water at the watershed outlet for two years. The samples were analyzed for Cd, Pb, Mn and Zn mass fractions. The effects of different components of the forest ecosystem in the watershed on heavy metals in water during the rainfall-runoff process were studied with comparisons and mechanistic analyses. The results showed that Cd, Pb, Mn and Zn mass fraction decreased by 0.721 μg·kg^-1, 6.482 μg·kg^-1, 0.012 8 mg·kg^-1 and 1.467 4 mg·kg^-1, respectively, and input of Cd, Pb, Mn and Zn through rainfalls was immobilized over 90% by the forest ecosystem. Cd, Pb, Mn and Zn mass fractions decreased stepwise with the rainfalls through out the canopy and the litter. In subsurface flow, Cd, Pb and Mn mass fractions increased while Zn mass fraction decreased. In tributary stream water, Cd, Pb and Mn mass fraction decreased sharply but Zn increased. In flow water at the watershed outlet, Cd, Pb, Mn and Zn mass fraction increased in varying extent. The canopy reduced Cd, Pb, Mn and Zn mass fraction by 0.697 μg·kg^-1, 6.194 μg·kg^-1, 0.008 9 mg·kg^-1 and 1.476 3 mg·kg^-1, respectively, and therefore was a crucially important layer of the forest ecosystem for reducing the heavy metals in water during the rainfall-runoff processes, followed by the litter layer.

Soil water content is crucial to vegetation rehabilitation on the hilly loess plateau. Dynamics of soil water under three types of water and soil conservation forests was monitored in this study with an EnviroSMART monitoring system. Soil water content was recorded at 20 cm intervals over a 0～150 cm soil profile every 30 minutes during the whole growing period. Results showed that the soil profile in the secondary forest had similar soil water storage to that in Pinus tabulaeformis plantation on terrace, and the storage in both forests was 1.4 times of that in Robinia pseudoacacia plantation. Secondary forests mainly used precipitation and soil water in upper layer, while plantation consumed water from deep layer.of the soil. Soil water content in the secondary forest increased from top to lower layer; in contrast, it decreased downward along the soil profile in P. tabulaeformis plantation. For the three types of forests, variation coefficients of soil water content decreased downward over the soil profile and soil water storage reached to the lowest level in August. Relatively, water storage in deeper layer delayed to deplete. Soil water in the 90～150 cm soil layer decreased from May to October in all tested forests. During the whole growing season, R. pseudoacacia plantation consumed 249.73 mm of soil water from the 0～150 cm layer with the largest daily consumption 4.70 mm, P. tabulaeformis plantation consumed 248.09 mm with the largest daily consumption 4.77 mm, and secondary forest consumed 129.40 mm with the largest daily consumption 2.28 mm. Results demonstrated that plantation consumes significantly more water than secondary forest; therefore, soil and water conservation forests should be established by imitating secondary forests.

A pot experiment with twenty-three open-pollinated Liriodendron chinense families from Liping of Guizhou at two nitrogen levels was conducted to investigate family variation and inheritance of nitrogen absorption and utilization efficiency related to nitrogen supply. The growth response of different families to nitrogen supply was found to be significant. Nitrogen efficiency of the families varied from 17.5% to 98.8%. The families were classified into two types according to the nitrogen efficiency, namely a stable type with high nitrogen efficiency and a sensitive type with low nitrogen efficiency. There existed significant family variation for nitrogen absorption and utilization efficiency among various organs and total plants at different nitrogen levels, besides leaf nitrogen utilization efficiency at low nitrogen level. The variation was under moderate or strong genetic control with family heritabilities ranged from 0.511 5 to 0.963 0. Stable type of families with high nitrogen efficiency exhibited greater biomass accumulation, more and larger leaves, more developed lateral and fibrous roots under low nitrogen level, because of high nitrogen and phosphorus absorption efficiency. However, the families had lower leaf nitrogen utilization efficiency.

Variations in amount and ring number of sapwood and heartwood were analyzed by using 350 benzidine-stained wood disks from 40 sampled trees of four Pinus tabulaeformis stands in limestone area of Taihang Mountain，varying in age and density. At the within tree level heartwood radius and sapwood width have no significant difference among four stem orientations (P>0.05). Sapwood width remained relatively constant along the tree stems from 0.50～1.00 m above the stem bases to 2.46～3.22 m below treetops，heartwood radius，heartwood area and sapwood area decreased with tree height，their longitudinal variations were well explained by stem cross-section diameter. At the individual tree level sapwood and heartwood amount varied greatly，and correlated best to DBH among selected tree variables. At the stand level sapwood and heartwood amount had significant difference (P<0.05)，their variation patterns were same as the stand age and stand growth level. The heartwood initiation cambial age was 13 years，number of heartwood rings increased with cambial age，the latter can account for 97.9% of variation of the former. Heartwood formation expressed as the number of new heartwood rings formed each year was found to increase from 0.5 rings per year at a cambial age of 40 years to 0.7 rings per year at a cambial age of 60 years. These results imply that it seems feasible to predict sapwood and heartwood amount and heartwood ring number by using inventory factors.

Different tree species have different sensitivities to damages from different kinds of fungi, insects, and vertebrates. Prices of forest products from different tree species also change over time. Mixed forests provide valuable options for sequential adaptive management. An adaptive optimization model under the risk of moose damage and prices variation has been developed to determine the initial proportion of Norway Spruce and Scots Pine in a mixed-species stand that would maximize the expected net present value. The results showed that the mixed stand was superior to the pure pine stand even no risk was considered, due to the biological mixture effect. However, when the risk of moose damage was considered, the superiority of the mixed stand was increased by 5% and 24% with or without incorporating the minimum stem number requirement of the Forest Act, respectively. The superiority of the mixed stand over a pure pine stand could be further increased by 6% when the price risk and selective thinning were included, compared to that the price was fixed

Improving our forest resources quality is the critical factor to solve under supply of our forest resources and the problem of deterioration of ecological environment. Based on lots of literatures, the author reviews the change of forest resources quality in China. Then the status quo and international contrast analysis were finished. The basic conclusion is that our forest resources quality presented a downward trend, and there is a wide disparity comparing with other forestry developed countries and the average level of the world. This conclusion is not only showing the status quo of the low quality of our forest resources, but also indicating the potential of improving our forest productivity, and the potential and feasibility of increasing our forest resources quality to reply the contradiction of wood supply and demand, the improvement of our ecological environment and the change of climate.

Crude protein, crude fat, crude fiber, starch, reducing sugar, total soluble sugar, free amino acids, four major inorganic elements (Na，K，Ca，Mg) and four trace elements (Fe，Cu，Mn，Zn) in the phloem of healthy and a blue stain fugus-infected Pinus armandii, and in the excrement of Chinese white pine beetle (Dendroctonus armandi) were measured. The results showed that the utilization efficency of nutrition by D. armandi was: reducing sugar>crude fat> total soluble sugar> crude fiber> starch> crude> protein. There were 17 free amino acids in the phloem of P.armandii, among which nine are requaired by D.armandi. In D.armandi’s excrement, K content was the highest among the major elements of Na,K,Ca,Mg, and Fe content was higher that of the other trace elements probably because it has great influence on the growth of blue stain fungus. Meanwhile, the blue stain fungus was able to decompose the nutrients from the phloem to the xylem, which provided more nutrients for the bark beetle, thus accelerating the weakness and death of the attacked host tree.

A pathogen was isolated from the larva of Parocneria orienta whose body was atrophic and rubescent. Its pathogenicity was testified by law of KOCH. It was identified as Brevundimonas bullata by physiological、 biochemical test and molecular systematic analysis. Toxicity of the bacterium to larva of Parocneria orientia was assayed by means of oral infection. Results showed that the linear regression relationship between the logarithm(y) of the bacteria concentration and the probability(x) of corrected mortality is Y=-9.785 1+6.667X, and the median lethal concentration is LC₅₀=9.28×10⁸ cfu·mL^-1. The result also showed that this pathogen had obvious function of restraining infection larva from taking food. The survival larva were obviously under the antitheses in length of body,avoirdupois,the ratio of eclosion,amount of nit and the ratio of hatch.

The research focus on the optimum technological conditions of poplar bark volatiles CO₂ supercritical fluid extraction (SFE-CO₂) taking it rate as index by orthogonal experiment. The results showed that the extraction rate of the volatiles of Populus simonii, using SFE-CO₂, is 3.56% under the best condition of 25 Mpa pressure, 50 ℃ and the extracting time of 60 min. The volatiles of the barks of P.×xiaozhuanica cv. ‘Baicheng-2’, P.simonii，P. russkii, P. berolinensis, P.pseudo-simonii, P.pseudo-simonii×P.nigra,P. ussuriensis, P.stalintz,P.alba×P.berolinensis and P.simonii were extracted using the same condition. The chemical components of volatiles were analyzed using gas chromatography-mass spectrometry (GC-MS). The research found that the major components of the volatiles are aldehyde, ester, acid, hydrocarbon, and mainly acid, while, the content of other substances is lower, less other big molecule components such as naphthalene, quinine, azulene and ketone.There are more variety of special compounds in the barks of P.berolinensis and P.stalintz. The behavioral reactions of males and females X. rusticus to the volatiles, 100 Μl, of ten kinds of poplar barks to volatiles were tested respectively using Y-tube olfactometer. It showed that 54.17% of male X.rusticus choose P.pseudo-simonii, comparatively, 58.33% of females choose P.pseudo-simonii×P.nigra and 54.17% of female X. rusticus choose the votaliles of P.pseudo-simonii and P.berolinensis. ANOVA analysis showed that the difference among the percentages　of the male X.rusticus choosing the ten kinds of volatiles are not significant (P＞0.05), but the females shown the significant reaction differences to the different volatiles (P＜0.05).

In this paper, population genetic variability and genetic structure of five sub-populations of Dendrolimus punctatus tabulaeformis (Lepidoptera:Lasiocampidae) were analyzed by using microsatellite markers. Eight microsatellite loci were used to detecte genetic structure of five sub-populations of D. punctatus tabulaeformis. The fragments lengths were from 78 bp to 430 bp. For each locus, 1-6 alleles were amplified. We found the genetic variability level was relatively high in all five sub-populations, as shown by P=87.50%, A=3.125 0, He=0.474 7, Ds=0.070 3－0.419 7, Fst=0.215 9, Nm=0.908 1. In this study, the expected heterozygosity (He) values showed that the genetic diversity of the subpopulation in pure Pinus tabulaeformis forest was higher than that of other sub-populations. According to the heredity parameters, gene flow was low and genetic drift was one of primary factors to lead to the genetic differentiation among five sub-populations of D. punctatus tabulaeformis. Overall, population genetic subdivision is high and the differentiations are also significant among sub-populations. The differences would probably be induced by local selection pressure of the insecticide treatments and the pure host food.

In this paper，the chemical changes of the cunninghamia lanceolata thinning wood treated in hot air and hot vegetable oil respectively for different processing temperatures and times were analyzed by chemical component analysis and FTIR analysis. The results showed that there were different degree decreases in the content of the holocellulose of treated samples during the heat treatment compared to reference samples，as the whole the content of the degraded cellulose of treated samples was smaller，meanwhile，the content of both of benzene-alcohol and Klason lignin of treated samples were increased. The chemical compositions of treated samples vary much when processing temperature was increased and times was lengthened during the heat treatment. In addition，the effect of heat medium on the chemical changes of treated samples was obvious，and the chemical changes of the samples when the treatment of hot oil appeared to be slightly lower than that of samples when the treatment of hot air under the same condition. Analysis variance showed that chemical compositions of treated samples among different processing temperatures，processing times and different heat medium reached highly significant difference. The FTIR of specimens indicated that the hemicellulose decomposed firstly when wood samples treated at 180 ℃，and some degradation of the cellulose was occurred at temperature of 200 ℃. The degradation of polysaacharide was accelerated in atmosphere. The variations of absorption intensity both of glucosidic bonds at 3 412, 1 050, 898 cm^-1and carbonyl peak at 1 736 cm^-1 and C—H bond stretching at 2 907 cm^-1 can reflect the variations in the chemical compositions of the samples when the treatment for different processing times and temperatures，it showed a good correlation between the variations in the chemical compositions of the samples and the improved dimensional stability of heat treated wood.

The secondary growth of trees determines timber production and has important economic value. In this review, we focus on a woody model plant, poplar, and a herbaceous model plant, Arabidopsis thaliana, and describe the signaling mechanism and gene regulation responsible for the vascular morphogenesis and functional organization. The main content is divided into several parts including vascular tissue function and formation, vascular cambium cell types and gene expression specificity, xylem and phloem key genes related to cell polarity, vascular cambium stem cell differentiation mechanisms, and the hormone regulatory networks in developing vascular tissues, with the emphasis on comparison of similarities and differences between the two species models.

This paper reviews research advances in any effect of Eucalyptus plantation and some factors (such as, forest ages, logging and afforestation, wildfire etc.) on the evapotranspiration, water yield, soil water and ground water, and indicates some problems and proposes expectations. Generally, the interception loss varied greatly in different Ｅucalyptus forests and the transpiration usually ranged from 0.5 mm to 6.0 mm per day. The evapotranspiration was affected by the leaf area index (LAI), forest density, content of soil water and irrigation, forest ages and conversion of Eucalyptus and other vegetations. And the water yield of catchments increases after logging such as the clearfelling, thinning or selective cutting and decrease after afforestation. The transpiration reduced and water yield of catchments increased with the increase of forest ages when Eucalyptus forests were old enough. The wildfires can increase the water yield. Eucalyptus plantations may consume the shallow ground water in the dry area, however there was no evidence that Eucalyptus plantations took the deep ground water. There are many problems that need to be resolved about the research of the effects of Eucalyptus forest on the hydrology in China, and the researches in main directions and key fields need urgently to be strengthened.

Bio-fuels as a renewable energy attracts much attentions and has been dramatically developed in the last few years. However, with fast expansion of first generation bio-fuel (grain based), its impacts on food price, food security and environment start to loom, which initiates hot debates over development of bio-fuels. Therefore, many countries, including China, start to pay much attention to forest-based bio-diesels. In this paper multi-methods were used, including literature review, key person interviews, questionnaire and field survey. The results showed that: Bio-diesels industry is starting to boom in China, since government sectors has set up targets and incentive policies on bio-diesels, feedstock and bio-diesels refining plants are being developed in large scale. In long-term, bio-diesel may have a sound future, however as a new industry, it still face a series challenges and should not go forward too fast. Currently, we should pay much attention to research activities such as breeding improved variety and high-yield techniques related to feedstock planting. (4) We should adjust the mode of bio-diesel development and create appropriate industry environment for bio-diesel development.

Unique species of tree， selective nutrients absorption and special environmental effects of pure plantation may lead to soil degradation. So study on the biochemical characteristics of soil and its reaction to external C and N disturbances of pure plantation can theoretically direct the nutrients management of forestland and control of soil degradation. According to fix-positional soil sampling， determining and field disturbance experiments in 4 typical pure plantation of larix kaempferi， Pinus tabulaeformis， Catalpa fargesii and Quercus aliena var. acuteserrata in Qinling Mountain， we can get following conclusions： Contents of organic-C， total N， enzyme activities of urease， amounts of microbes and contents of micro-biomass C and N in soil of broad-leaved forests are all more than its of needle-leaved forests except for enzyme activities of sucrase and catalase. External fertilization of C (cane sugar) can popularly raise the enzyme activities of urease， sucrase and catalase， amounts of microbes and contents of micro-biomass C and N， and rates of litter decomposition of planted forests (both needle-leaved forests and broad-leaved forests). External fertilization of N (urea) can raise the enzyme activities of urease， amounts of microbes and contents of micro-biomass C and N， and rates of litter decomposition of needle-leaved forests， but lower the involved biochemical indices of broad-leaved forests. In summary， as a whole， broad-leaved forests are conductive to soil improvement， whereas， needle-leaved forests are harmful. Both C and N are limited nutrients for biochemical characteristics of needle-leaved forests， whereas， only C is limited for broad-leaved forests， and N is not lack， more N has no good but is harmful.

The eddy-covariance system monitored the carbon flux of Populus forest ecosystem in the middle and lower reaches of Yangtze River in Yueyang, Hunan Province. Daily and monthly variation of carbon flux between forest ecosystem and the relationship of carbon flux and environmental factors were analyzed. The results showed that the regulated variation and process of day and month of carbon flux of forest ecosystem. In daytime, the ecosystem began to absorb CO₂ at about 7:30 am, and reached to the max. at about 12:00, then went down slowly, at about 18:00, the ecosystem began to release CO₂. At the period of the end of March and the early of April, the Populus began to unfold leaves, and the forest ecosystem started to absorb CO₂, namely carbon sink. At the period of the end of October to the early of November, the photosynthesis of leaves stopped by defoliation, at the same time, the forest ecosystem became carbon source. The paper also analyzed the relationships of carbon flux of forest ecosystem and environmental factors. The results were as follows: when the PAR>1 μmol·m^-2s^-1, the relationship of carbon flux and PAR was different in different range of temperature. When the PAR>1 μmol·m^-2s^-1, air temperature and carbon flux had quadratic equation. Namely when the air temperature arose, the carbon flux of nighttime was augmented. The nighttime CO₂ flux and soil temperature in 5 cm deep had exponential correlation. Choosing a day from different month and ridding off the carbon flux for u*<0.2 m·s^-1, the 30 min average carbon flux in nighttime and soil heat flux in 2 cm deep that had the relationship of exponential correlation.

A short-term exposure experiment of 19 native plant species was carried out from May 2006 to August 2008 at two sites with different stresses of acid rain pollution (HP: Guangzhou Petrochemical Factory in Huangpu represents a contaminated area; LXH: Liuxihe National Forest Park represents a relative clean area). Total 76 soil samples, collected from rhizospheres of those tested plants and the nearby bulk soil, were analyzed to investigate chemical behaviors of rhizosphere soil under the different acid rain pollution. Meanwhile, soil samples of rhizosphere of Schima superba and the nearby bulk soil under a longer-term pollution were also collected and analyzed for further confirmation. The results showed: (1) Soil major ions (H⁺, Al³⁺, Cl^-, NO₃^-, SO₄^2-, K⁺, NH₄⁺) contents in the serious acid rain stress area were higher than that in the relative clean area and the serious acid rain stress induced an increase in leaching Ca²⁺, however promoted Ca²⁺ transfer from bulk soil to rhizosphere soil. (2) The nutrient content of rhizosphere soil was in general higher than that of bulk soil. (3) There were antagonistic actions and negative correlations between Ca²⁺ (as well as organic matter) and Al³⁺ in rhizosphere soil. (4) Acid rain significantly caused Al release, the ratio of exchangeable Al and exchangeable Ca (Al/Ca) of the soil in serious acid rain pollution area was larger than that in the relative clean area. (5) There was a close correlation between Al³⁺ and organic acid in the soil, which suggested that the plant roots would excrete more organic acid with the enhancing acid stress for complexing Al³⁺ in the root sphere to lessen the toxicity of aluminum.

‘Dashi Early Ripening' plums were treated with 0.1, 0.5, 1 μL·L^-1 1-methylcyclopropene (1-MCP) at ambient temperature for 12 h following harvest to evaluate the effectiveness of 1-MCP in extending the shelf life. The fruit firmness, soluble pectin, malondialdehyde (MDA) content, respiration rate, superoxide dismutase (SOD) and catalase (CAT) activities as well as soluble sugar and titratable acidity content of the treated plums were measured over thereafter 12 d during which the plums were stored in ambient temperature. The result showed that the plums treated with 1 μL·L^-1 1-MCP remained consumer quality better than that with the other treatments. Their firmness was 249% higher than that of control on the 3rd d of storage, their MDA content was 40% lower than that of control on the 9th d of storage, the titratable acidity was 16.5% higher and the soluble sugar content was 25% higher than that of control at the end of the storage. The treatment with 1 μL·L^-1 1-MCP lowered the respiration rate and soluble pectin content, and retarded the respiration peak in comparison with control. The treatment also maintained relative higher SOD, CAT activities. It was concluded that 1 μL·L^-1 1-MCP treatment was efficient for extending the shelf life and maintaining the quality of ‘Dashi Early Ripening' plums.