Dynamical patterns of mineral elements during decomposition processes were investigated for seven common canopy species in a subtropical evergreen broad-leaved forest by means of litterbag technique over 2 years. The species studied are representative for the vegetation in the study area and differed significantly in chemical qualities of their litter. No significant relationships were found between decomposition rate (percentage dry mass remaining and decomposition constant k) and initial element concentrations. However, there were significant correlations between the percentage of dry mass remaining and the mineral element concentrations in the remaining litter for most cases. The rank of the element mobility in decomposition process was as follows: Na = K > Mg ≧ Ca > N ≧ Mn ≧ Zn ≧ P > Cu ≫ Al ≫ Fe. Concentrations of K and Na decreased in all species as decomposition proceeded. Calcium and Mg also decreased in concentration but with a temporal increase in the initial phase of decomposition, while the concentrations of other elements (Zn, Cu, Al, and Fe) increased for all species with exception of Mn which revealed a different pattern in different species. In most species, microelements (Cu, Al, and Fe) significantly increased in absolute amounts at the end of the litterbag incubation, which could be ascribed to a large extent to the mechanism of abiotic fixation to humic substances rather than biological immobilization.

Community structure characteristics and vegetation damage degree were investigated and analyzed in a forest around village, which had been long term exposed to ambient atmospheric pollution stress, to study the influence of airborne pollutant emissions from the concentrated ceramic industries on vegetation. Field survey was carried out in a semi-natural secondary forest on hilly land, Nanhai District of Guangdong Province, for the tree layer in ten quadrates with the total area of 10×(10 m×10 m), and for shrub and herb layers in eight subquadrates with the total area of 4×(5 m×5 m). Results showed that exotic Eucalyptus exserta and Eucalyptus urophylla were dominated over the community, followed by native tree species, Schefflera octophylla and Bambusa gibba, with the importance value (Iv) of 26.75, 17.08, 16.27 and 11.50, respectively. Among all tree species, Eucalyptus exserta and Pinus massoniana were most severely damaged with nearly 100% damaged rate. Bambusa gibba and Dalbergia balansae were injured with damaged rate of 85.1%–68.3%, however, Eucalyptus urophylla, Celtis sinensis, Helicia cochinchinensis, Cinnamomum burmanni and Vitex negundo revealed moderate injuries (45%–57.5%). Most of other indigenous species including Schefflera octophylla, Viburnum odoratissimum, Desmos chinensis, etc. showed less injured symptoms under the pollution stress. Compared with species in tree layer, damages of undergrowths were largely less. These results suggested that attention and concern should be paid on those introduced Eucalyptus species which had ever been widely used for forest restoration in degraded hilly lands of south China since 1970–1980s, due to their fast growing aspect. The results also demonstrated the potentials and perspectives by developing native species as target plants for restoration of degraded area at similar polluted location, which may provide scientific base for scientists to study and understand the functional aspects of native species and process-based interactions with pollution stress.

The injury tolerance of cell plasma membrane and the correlative enzymes activities of plasma-membrane protection system in the Ulmus pumila leaves treated by nine concentrations (0.3%, 0.6%, 0.9%, 1.2%, 1.5%, 1.8%, 2.1%, 2.4%, 3.0%) of Na₂CO₃ and NaHCO₃ mixtures were studied in a greenhouse of Northeast Forestry University, Harbin, China. The rate of electrolyte leakage (REL) and SOD (Superoxide dismutase) activity in leaves of different samples were determined. Results showed that the REL in leaves of U. pumila presented a slowly increasing trend at the salt concentrations less than 1.5%, which indicated that cell plasma membrane of U. pumila leaves had rather strong resistance to the injury of salt ion, and had a significant increase at the salt concentrations more than 1.5%. The SOD activities in leaves of U. pumila presented an increased trend at salt concentrations less than 1.5%, the growth of seedlings did not decline, and tress and leaves had no symptom of injury, while the salt concentrations exceeded 1.5%, SOD activities sharply decreased and REL increased promptly.

DNA was extracted from the strain of pathogen of poplar leaf blight using a modified CTAB method. ITS sequence (601bp) was initially amplified from the pathogen by using the universal primers ITS1 and ITS4 (registered No. DQ011257). Comparing to the nucleotide sequences acquired from GenBank database, the strain is clustered into the homogeneity with Alternaria alternate (AY787684) and Alternaria alternate (AY354228), with a homology of 98%, thus the strain was checked as Alternaria alternata (Fr.) Keissler. The optimal conditions for conidia germination and mycelium growth of the pathogen were tested. The optimal temperature for conidia germinating and mycelium growth is 25°C, and the optimal pH value is 6. Mycelium grows rather slowly at 10 °C and 30 °C and growth stops at above 35 °C. Among the six culture mediums tested, PDA + poplar leaf juice medium is most favorable for mycelium growth.

Genetic diversities and genetic differentiations of the four Pinus koraiensis populations (Gaofeng Forestry Farm at Tangwanghe in Yichun City, Erdaobaihe Town in the Changbai Mountains, Shengshan Forestry Farm in Heihe City, in China, and the suburb of Vladivostok City in Russia) were analyzed by using ISSR-PCR technique. The results of 15 primers amplification showed that the ratio of polymorphic site of P. koraiensis population was 60.7%. Each primer had 3.6 polymorphic sites. The diversity levels of the four P. koraiensis populations were rather higher compared with those of other Pinaceae species. The genetic diversity levels of P. koraiensis populations grown in the center region were higher than those grown in the edge zone. The genetic diversity of P. koraiensis mainly came from the interior of the population, accounting for 73% of total genetic diversity. There were no positive correlation between genetic distances and geographical distances for the four P. koraiensis populations. The gradual decrease of natural distribution region of P. koraiensis was due to anthropic destroy and environmental factors (i.e. fire and wind throw), rather than the lower genetic diversity.

To assess the effects of savanna afforestation on soil phosphorus (P) transformations in eastern Horqin Sandy Land, China, P fractions and phosphomonoesterase activities were examined in two soil horizons (0–5 cm and 5–20 cm) under a savanna and an adjacent 30-year-old Mongolian pine (Pinus sylvestris L. var. mongolica Litv.) plantation on a P-deficient semi-arid sandy soil. The results showed that all soil P fractions and phosphomonoesterase activities decreased with soil depth at both sites except that labile organic P under the plantation was constant with soil depth. In contrast to savanna, soils under Mongolian pine plantation had lower phosphomonoesterase activities and concentrations of all P fractions (with an exception of Al-P), lower proportions of organic P and Ca-P in total P, and higher proportions of labile P, Al-P and Fe-P in total P. These results suggested that P transformations mainly occurred in surface soils, and P recycled through litter-fall was the most important source of plant available P. Mongolian pine afforestation enhanced the bioavailability of both organic P and Ca-P, simultaneously reduced soil P pools, indicating that protection of forest floor and P fertilization are necessary to maintain the sustainable functioning of Mongolian pine plantations.

Microorganism DNA of rhizosphere soil from Pinus koraiensis and Pinus sylvestriformis were extracted by proteinase K based on SDS method, CTAB method, PVP (polyvinylpolypyrrolidone) method, and freezing and thawing method and the crude DNA from rhizosphere soil were purified by dialysis method, silver beads absorption method, and squeezing DNA gel method. The results of different extracting and purifying methods were compared and evaluated. Results indicated that the best method of extraction for microorganism DNA in rhizosphere soil was proteinse K based on SDS method with high salt concentration of 1.0% (w/v) NaCl, which could effectively eliminate humic acids and other impurities. The dialysis method was suitable to purify DNA from rhizosphere soil because of effectively removing brown matters and humic acids and the purified products were suited to PCR amplification. Squeezing DNA gel method was also a good purification method with the advantage of inexpensive in cost and efficient in use.

In process of ecological construction in typical region of upper reaches of Yangtze River, China, the mixed plantations at the ages of 10–20 present a trend to be pure forests and degeneration. Soil samples including stratified soil and total soil were taken from 4 typical profiles in the mixed plantation of Alnus cremastogyne and Cupressus funebris in Yanting County in central Sichuan, China. Soil indices of the plantation were compared with those of natural forest in Gongga Mountain in the same region. The results revealed that structural quality of soil in plantation was significantly lower than that in natural forests. The degradation of structural quality of soil in plantation was one of key factors for plantation degeneration. The degradation causes of structural quality of soil were analyzed. Aanthropogenic disturbance and absence of effective protection and scientific management are the main reason for degradation of structural quality of soil in plantation. The main countermeasures, e.g. forest reservation, ecological rehabilitation, litter horizon rebuilding as well as organic fertilizer application, were proposed to improve the structural quality of soil in plantation.

The dynamics of soil organic carbon (SOC) was analyzed by using laboratory incubation and double exponential model that mineralizable SOC was separated into active carbon pools and slow carbon pools in forest soils derived from Changbai and Qilian Mountain areas. By analyzing and fitting the CO₂ evolved rates with SOC mineralization, the results showed that active carbon pools accounted for 1.0% to 8.5% of SOC with an average of mean resistant times (MRTs) for 24 days, and slow carbon pools accounted for 91% to 99% of SOC with an average of MRTs for 179 years. The sizes and MRTs of slow carbon pools showed that SOC in Qilian Mountain sites was more difficult to decompose than that in Changbai Mountain sites. By analyzing the effects of temperature, soil clay content and elevation on Soc mineralization, results indicated that mineralization of SOC was directly related to temperature and that content of accumulated SOC and size of slow carbon pools from Changbai Mountain and Qilian Mountain sites increased linearly with increasing clay content, respectively, which showed temperature and clay content could make greater effect on mineralization of SOC.

The prevalence of insect pests was studied on rice BR11 (mukta) as understory crop grown in association with 11 years old selected tree species viz, Akashmoni, Jhau and Albida in the field laboratory of the Department of Agroforestry, Bangladesh Agricultural University (BAU), Mymensingh during the period from July to December, 2003. Among the three species Albida and Jhau possessed the largest canopy and there light penetration rate were high. On the other hand, Akashmoni had the lowest canopy but it penetrated low amount of light. Albida-rice association showed the lowest infestation of major rice insects followed by Jhau-rice association, while Akashmoni-rice association showed the highest insect infestation. Light intensity in the control plot (absent of tree species) was maximum and it caused minimum severity of insects infestation as compared to other associations. From the result it appeared that light interception has the relationship with insect population in rice. Therefore, tree species having sparse canopy which allowed easy penetration of sunlight is suitable for tree-rice agroforestry system.

Garjan (Dipterocarpus turbinatus Gaertn. F) is a highly ectomycorrhizal tree species growing in hilly areas of Bangladesh. The horizontal distributions of ectomycorrhizas (ECM) in different distances (1, 2, 3 & 4m) from the tree base were determined in 5, 10 and 20-year-old D. turbinatus plantations of Chittagong University Campus (CUC) in 2003. The ECM infection (%) in roots was counted at three hill positions (top, mid and bottom) for each of the plantations. Samples of 1000 cm³ rhizosphere soil were collected from underneath the trees at different horizontal distances. The percentage of infection at different distances and hill elevations varied considerably. In 5 and 10-year-old plantations, the occurrence of infection (%) was rapidly declined with increasing distances, while in 20-year-old plantation, the infection increased sharply with increasing distances from the tree base. The highest infection (81.33%) was found at 4 m distance from the tree at bottom hill in 20-year-old plantation and the lowest (55.33%) at the same distance at the top of the hill in 5-year-old plantation.

The second-instar healthy larvae of Clostera anastomosis were collected in the artificial woodland of poplar in Shuangcheng Town, Heilongjiang Province, China. The dead larvae of C. anastomosis infected by granulosis virus (GV) of Clostera anastomosis were grinded to obtain GV. The GV viral pesticide was diluted to seven concentrations, 1.58×10³PIB·mL⁻¹, 1.58×10⁴ PIB·mL⁻¹, 1.58×10⁵ PIB·mL⁻¹, 1.58×10⁶ PIB·mL⁻¹, 1.58×10⁷ PIB·mL⁻¹, 1.58×10⁸ PIB·mL⁻¹ and 1.58×10⁹ PIB·mL⁻¹ and the fresh poplar leaves were dipped in the seven concentrations liquids to feed the larvae. After nine days the mortality of larvae was investigated. The minimum corrected mortality (7.32%) of larvae was observed at concentrations of 1.58×10³PIB·mL⁻¹ and the maximal mortality (97.36%) was observed at concentration of 1.58×10⁹ PIB·mL⁻¹. The regression equation between the logarithm of the virus concentration and the mortality was y=1.946+0.558x. The LC₅₀ was 2.97×10⁵PIB·mL⁻¹. The LT₅₀ for the virus concentration of 1.58×10⁵, 1.58×10⁶, 1.58×10⁷, 1.58×10⁸, 1.58×10⁹ PIB·mL⁻¹ were 8.55d, 6.89d, 5.9d, 4.65d, and 4.08d, respectively, shorting gradually with the concentration increasing. It is concluded that the toxicity of Clostera anastomosis GV is very strong and as a kind of insecticides it has big potential in practical application.

Electrical and electromagnetic shielding wood-metal composite was prepared by using electroless nickel plating. The effects of solution amount, plating time and plating temperature on surface resistivity and electromagnetic shielding effectiveness were investigated. And P content, microstructure and surface feature of layers obtained at different temperatures were analyzed by energy dispersion spectrometer (EDS), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that layers with higher electro-conductivity and electromagnetic shielding effectiveness were obtained under the optimum conditions that plating solution was 500 mL, plating time was 30 min and plating temperature was 62°C. The results showed by EDS analysis that P content increased gradually in a small extent with plating temperature increased. It was showed by XRD and SEM analysis that layers plated at different temperatures were all microcrystalline structure and uniform and successive, which had noticeable metal luster. Those indicated that plating temperature had little influence on microstructure and surface feature under pH value invariable.

The basal theory of Gauss-MRF is expounded and 2–5 order Gauss-MRF models are established. Parameters of the 2–5 order Gauss-MRF models for 300 wood samples’ surface texture are also estimated by using LMS. The data analysis shows that: 1) different texture parameters have a clear scattered distribution, 2) the main direction of texture is the direction represented by the maximum parameter of Gauss-MRF parameters, and 3) for those samples having the same main direction, the finer the texture is, the greater the corresponding parameter is, and the smaller the other parameters are; and the higher the order of Gauss-MRF is, the more clearly the texture is described. On the condition of the second order Gauss-MRF model, parameter B1, B2 of tangential texture are smaller than that of radial texture, while B3 and B4 of tangential texture are greater than that of radial texture. According to the value of separated criterion, the parameter of the fifth order Gauss-MRF is used as feature vector for Hamming neural network classification. As a result, the ratio of correctness reaches 88%.

A study was conducted on the isolation of poplar (Populus × euramaricana (Dode) Guineir cv. l-72/58) wood components with aqueous acetic acid (AcOH) containing small amounts of sulfuric acid. The reaction time, concentration of acetic acid, ratio of liquor to wood, and concentration of acid catalyst were investigated to examine their effects on the fractionation of wood components. The three main separated components were characterized. The results showed that the optimum conditions for fractionation of poplar wood components were: 0.3% H₂SO₄ in reaction solution, ratio of liquor to wood 6, reflux time 3 h, and 90% AcOH. The residues were mainly composed of α-Cellulose and hemicellulose. The water insoluble precipitate (acetic acid lignin, AcL) had a low weight-average molecular weight range from 341 to 253 (Mw) and a narrow molecular weight distribution from 1.1 to 1.2. The sugar analysis revealed the solubilized products resulted mainly from hemicellulose and exited as monosaccharides.

Chemical ecology of the spruce bark beetle Ips typographus (L.) was reviewed. The outbreak of I. typographus in central Europe triggered extensive research on chemical ecology. Males initiate host location and produce semiochemicals which attract both males and females. A successful mass attack must first overcome the resistance of the host tree. Pioneer I. typographus evolved to use the resin flow of host trees as kairomones in host location, and synthesized semiochemicals initially to detoxify the resin. If small bark beetle populations infest healthy trees, mass attack is prevented by host resistance. Nine monoterpene alcohols were found in male hind-guts, including cis-verbenol (cV) and 2-methyl-3-buten-2-ol (MB) which are regarded as primary aggregation pheromones, and a low proportion of Ipsdienol (Id) which increases attractiveness of cV and MB. Verbenone (Vn) and Ipsenol (Ie) are anti-aggregation pheromones, that play important roles in adjusting attack density and insect density under the bark. Non-host volatiles are repellent to I. typographus, so that beetles do not waste energy boring into non-host trees. The relationship between host resistance, pheromone compounds and behavior, non-host volatiles, bioassays and mass trapping are reviewed. Results of field bioassays stressed that traps baited with specific pheromones could be used as a reasonable protection measure.

Precipitation in Heilongjiang Province of China increased slightly from 1960 to 2000. Adopting the method proposed by Arthur N. Samel, we separated monsoon rainband rain and calculated the initial and final date of monsoon rainband of each year and each station. For the period of 1960–2000, the change of annual precipitation in Heilongjiang Province, with an increasing trend of 2.229 mm per decade, is not significant; the duration and total monsoon rain decreased significantly, with a decreasing trend of −6.9 day per decade and −17.5 mm per decade separately. That change comes from early leaving date of summer monsoon rainband for the period of 1960–1975 and later arriving date of summer monsoon rainband for the period of 1990–2000. The weakening of summer monsoon makes its contribution to the annual precipitation decreased significantly, with a decreasing trend of 4.4 % per decade.

This paper summarized the studies on biomass production, biomass growth models, biomass measurement, biomass and forest density, as well as carbon storage of poplars in China in recent 20 years. The existing problems on research of poplar biomass are discussed and some suggestions for enhancing biomass of poplars are put forward.

An investigation was conducted on distribution pattern, site condition and population structure of yew Taxus cuspidata Sieb. et Zucc. in Muling Forest Bureau of Heilongjiang Province, China in April, 2005. Results showed that yew is mainly distributed under the main storey of natural mixed forest of conifer and broadleaf, the soil moisture content of the yew site is high (40%–60%), the pH value of soil is relatively lower (4.7–5.5), and that the population structure of wild yew is not rational, belonging to the degeneration population, which is one of the reasons leading to the population decline. Although the site conditions of Muling area are suitable for the growth of wild yew, the population of wild yew shows a decline tendency, due to the fact that the middle-sized adult yew trees have been cut, young yews are often grazed by wildlife, and that the trunks of adult yew tend to be hollow.

Bacteriostasic activity experiments on anthocyanin extracted from Malva sylvestris inhibiting Staphylococcus aureus, Escherichia coli, Aspergillus niger, were conducted by using solid and liquid culture methods. The results showed that the anthocyanin of M. sylvestris had a great bacteriostasic activity to Staphylococcus aureus but had no bacteriostasic activity to both Escherichia coli and Aspergillus niger. The bacteriostasic activity to Staphylococcus aureus increased with increasing content of anthocyanin of Malva Sylvestris in the solid-culture experiment. The average diameters of bacteriostasic circle for Staphylococcus aureus was 6, 13.5, and 16.0 mm at 10g·L⁻¹, 20g·L⁻¹, and 30g·L⁻¹ contents of anthocyanin of M. sylvestris, respectively. Moreover, this bacteriostasic activity kept long time as anthocyanin was of the high concentration.