Collapse-type shrinkage is one of highly refractory drying defects in low-medium density plantation-grown eucalypt wood used as solid wood products. Basic density (BD), microfibril angle (MFA), double fibre cell wall thickness (DWT), proportion of ray parenchyma (RP), unit cell wall shrinkage, total shrinkage and residual collapse, which are associated with collapse-type shrinkage characteristics, were investigated by using simple regression method for three species of collapse-susceptibleEucalyptus urophyll,, E. grandis andE. urophylla×E.grandis, planted at Dong-Men Forest Farm in Guangxi autonomous region, China. The results indicated that: unit cell wall shrinkage had a extremely strong positive correlation with BD, moderately strong positive correlation with DWT, and a weakly or moderately negative correlation with RP and MFA; total shrinkage was positively correlated with BD, DWT and RP and negatively related to MFA, but not able to be predicted ideally by any examined factors alone owing to lower R² value (R²≦0.5712); residual collapse was negatively correlated with BD and DWT, linearly positively correlated with MFA, and had strongly positive linear correlation with RP. It is concluded that BD can be used as single factor (R²≥0.9412) to predicate unit cell wall shrinkage and RP is the relatively sound indicator for predicting residual collapse

Flavonoids in plants is very important in its ecological role and economic value. The dynamic features of flavonoids content in different organs of larch (Larix gmelinii) at different light and temperature conditions were investigated in this study. Results showed that the order of flavonoids content in different organs from high to low was 7.78% (stem bark)>2.79% (leaves) >1.72% (branches) >1.19% (stem xylem)and different organs had a great seasonal variation in flavonoids content, but the change of flavonoids content at different temperature was not obvious in different organs., The content of flavonoids in barck had, a positive correlation with temperature (R ²=0.75), but that in other organs had slight variation with the change of temperature. For all the tested organs, the flavonoids content in summer and autumn was approximately 3–4 times higher than in spring and winter. This is attributed to the great stress from environmental physical variables such as UV radiation, high temperature that induce the accumulation of flavonoids. The flavonoid content of sun leaves was evidently higher than that of shade leaves, and leaves at upper part of canopy had a higher flavonoids content compared with that at other parts. This result indicates that sun radiation could improve flavonoids production in leaves (R ²=0.76). The flavonoids may actively evolve in plant defenses to environmental stress, protecting larch from the damage of high temperature and radiation, and its main function is different in different organs.

Eight provenances of 19-year-oldPicea koraiensis Nakai from the provenance trials of Maoershan (45°20′N, 127°30′E), Liangshui (47°10′N, 128°53′E) and Jiagedaqi (50°24′N, 124°07′E) in Northeast China were investigated to analyze the genetic variation in growth characteristics (tree height and diameter) and wood characteristics (tracheid length, tracheid diameter, tracheid wall thickness, annual ring width as well as wood density). Great variation in height growth and breast height diameter growth was observed among the provenances, and along with the increase of tree age, these provenances presented different geographic adaptability. The growth characteristics ofPicea koraiensis stand at age of 10 in Maoershan and Liangshui provenance trials had a positive correlation with longitude, and with increase of tree age to 15 and 19, the tree growth of the provenances displayed a significant positive correlation with latitude as well as altitude. For wood characteristics, great variation was also found among the provenances. There exists a close relation between growth characteristics and wood properties of the provenance. The height and breast height diameter growth of the provenance had a positive correlation with tracheid diameter and annual ring width, and a negative correlation with tracheid wall thickness and wood density. Genetic performance of the provenance in all above characteristics was also investigated in order to provide more useful information for comprehensive selection of this species for pulpwood and plywood production.

Female inflorescence ofBetula platyphylla was sampled at an interval of each two days to analyze the background of gene expression in floral phase. On the basis of SMART strategy, the driver cDNA was obtained from total RNA of the last sample and the tester cDNA was from that of the others by RT-PCR which were subsequently used to construct a subtracted cDNA library. The result of the ESTs (expression sequence tags) blastX showed that the genes in the subtracted cDNA library could be mainly clustered into 5 groups related to metabolism, transportation and signal transduction, cell cycle, stress response, and regulation. The relationship between gene expression and development was also discussed.

The rates of soil N mineralization at soil depths of 0–15, 15–30, 30–45 and 45–60 cm and moisture regimes were measured at three sand-fixation plantations ofPinus sylvestris var.mongolica by laboratory aerobic incubation method. The results showed that average rates of soil net N-mineralization across soil depth varied from 1.06 to 7.52 mg·kg⁻¹·month⁻¹ at soil depths from 0 to 60 cm. Statistical analyses indicated that the effects of different soil depths, moistures and their interactions on net N-mineralization rates were significant (P<0.05). The net N-mineralization rates significantly decreased with increasing soil depths and at depth 0–15 cm accounted for 60.52% of that at depth of 0–60 cm. There was no difference in soil net N-mineralization rates between half and fully-saturated water treatments, however these rates were substantially higher than that without water treatment (P<0.05). The factors influencing N mineralization process have to be studied further in these semiarid pine ecosystems.

Three types of landscape boundary (forest/pepper field, forest/cabbage field, and forest/grassland) were selected in the aird valley of upper reaches of Minjiang River, southwestern China. On the basis of vegetation diversity, the depth of edge influence (DEI) on different types of landscape boundaries was estimated using principal components analysis (PCA) method and moving split-window techniques (MSWT). The results showed that in the 5 transects, PCA method was able to detect the edge influence depth with 3 transects, while MSWT could explain 4 transects. It is concluded that PCA and MSWT both can be used to detect the depth of edge influence within 50 m from the edge to the interior. Similar conclusions were drawn in the forest of each transect with the two methods, but no similar conclusions were drawn in the pepper field of each transect. Although the two methods have advantages and disadvantages respectively, they are useful tools for characterizing edge dynamics. Comparing the two methods, MSWT is more successful.

The flora and community physiognomy of degraded plantation ecosystems on purple soil were investigated in Ninghua County of Fujian Province, China to understand the relationship between plant diversity and ecosystem processe. Four different restoration communities (labeled as ecological restoration treatment I, II, III and IV) were selected by space-time replacement method according to the erosion intensity in degraded purple soil ecosystem. The results showed that there were totally 86 plant species belonging to 78 genera and 43 families in the degraded purple soil ecosystem. Of the 15 types of distribution area in spermatophyte genus, 12 types were found in the purple soil ecosystem. Along restoration gradient from low to high, plant growth type and life form spectra became abundant more and more, and the spermatophyte genera for each distribution area type and genera numbers for different foliage characters increased as well. It is concluded that the plant flora and physiognomy in ecological restoration process become more complex and diverse, indicating that the forest ecosystem on purple soil tends to be more stable.

Peltophorum dubium seeds were set to imbibe with four treatments, soaked with solution Captan 0.2% under 10 and 27°C, PEG 6000-1.0 MPa under 10 and 27°C. For each treatment there were four replicates with 40 seeds incubated in 9-cm Petri dishes with double filter paper moistened with testing solution. The imbibition curves showed that the final weight increase were from 70% to 150% in the treatments when inbibition entered a lag phase. Seeds were tested for effects on germination of five treatments: control group (nonprimed), primed with PEG6000-1.0 MPa at 10 and 27°C, primed with Captan 0.2% at 10 and 27°C. For each treatment, there were three sub-treatments: seeds were soaked in distilled water for 12,24 and 36h before the energy test. Germination percentages of nonprimed seeds and primed in PEG 27°C soaked in distilled water during 12 h were the highest, reaching 100%. The lowest germination percentage occurred primed seeds with PEG6000 27°C and soaked in distilled water during 36 h, which was only 52%. Germination mean time of primed seeds in PEG at 10°C, soaked 24 h was 1.08 days, mean time of primed seeds in PEG at 27°C soaked 12 h was 2.42 days. Accelerated ageing results showed low or no germination after ageing 72 h. Control group had a higher germination percentage and seeds were more resistant to deterioration than those in primed groups, both in Petri dish (27°C) and vermiculate (room temperature).

The age structure of the naturalZoysia japonica clonal population at Qipan Mountain in Huishan Scenic Spot of Shenyang, Liaoning Province, China was studied using the morphological method in 2003 and 2004. The dynamics of leaves were recorded and the dynamics of tiller and rhizome in the growing season were observed. The results indicated that the rhizomes formed in different years changed in color and rigidity. Its internodes produced in autumn became shorter. The number of naked nodes changed with the tiller age. Rhizome and tiller characters were used as a foundation for judging the ages of modules in this study. The longevity of tiller and rhizome was 3 years at most. At the beginning of the growing season, 2-year-old tillers and rhizomes predominated. Then 1-year-old tillers and rhizomes increased rapidly and became dominant in July. The proportion of buds to tillers on quantity was stable at about 30% in the mid-phase of the growing season and rose to about 50% in autumn. The seasonal dynamics of tiller, rhizome and bud was very important to guarantee the sustained existence of theZoysia japonica population. The turnover of modules was the mechanism of sustaining the rejuvenation of theZoysia japonica clonal population.

A new endophytic antagonistic fungus,Chaetomium spirale ND35 fromPopulus tomentosa, was reported. The bio-control trials ofC. spirale ND35 against theValsa Canker of apple were preliminarily investigated. The results of dual culture on PDA plate showed that C.spirale ND35 was capable of strong antagonism againstValsa ceratosperma, and for inhibiting the mycelial growth ofV. ceratosperma., the crude extract of liquid culture of corn steep powder broth was more effective than that one of malt extract broth (MEB). The results of bio-control in greenhouse and field indicated that the disease incidence of apple tree treated withC. spirale ND35 was lower significantly than that treated by other methods. The re-isolation experiment suggested thatC. spirale ND35 could colonize in stems and branches of apple trees successfully, and the ND35 colonization rate of the treatment with solid wheat bran culture was higher than that of corn steep powder broth, but the field experiment result the control effect of liquid culture ofC. spirale ND35 was better than that of solid culture.

The restoration of forest landscape has drawn much attention since the catastrophic fire took place on the northern slope of Great Xing'an Mountains in 1987. Forest canopy density, which has close relation to forest productivity, was selected as a key factor to find how much the forest quality was changed 13 years after fire, and how fire severity, regeneration way and terrain factors influenced the restoration of forest canopy density, based on forest inventory data in China, and using Kendall Bivariate Correlation Analysis, and Distances Correlation Analysis. The results showed that fire severity which was inversely correlated with forest canopy density grade was an initial factor among all that selected. Regeneration way which did not remarkably affect forest canopy density restoration in short period, may shorten the cycle of forest succession and promote the forest productivity of conophorium in the future. Among the three terrain factors, the effect of slope was the strongest, the position on slope was the second and the aspect was the last.

The correct method used in forest soil respiration measurement by Li-6400 is a premise of data quality control. According to the study in a larch plantation, collars should be inserted at 12 hours in advance to efficiently reduce the influence of CO₂ spring-out. Moreover, collar insertion depth substantially affected soil respiration measurement, i.e., when collar was shallowly inserted into soil, transversal gas diffusion and the CO₂ re-spring-out caused by unstable collars in the measurement could lead to overestimating soil respiration rate; however, when collar was deeply inserted into soil, root respiration decline caused by root-cut and the most active respiratory of the surface soil separated by the inserted collars could lead to underestimating soil respiration rate. Furthermore, an error less than 5% could be guaranteed in typical sunny day if the target [CO₂] was set to the mean value of ambient [CO₂] in most time of the day, but it should be carefully set in early morning and late afternoon according to changing ambient [CO₂]. This protocol of measurement is useful in real measurement.

C. acuminata seedlings cultivated in greenhouse were transplanted into the fields with 5 designed planting densities (11, 16, 25, 44 and 100 plants·m⁻²) in May of 2004 and were harvested in the middle of September of 2004. The seedling growth indexes including plant height and crown width, biomass allocation, camptothecin (CPT) content and CPT yield of different organs (young leaf, old leaf, stem, and root) were studied. For the 5 selected planting densities, the plant biomass, height, crown width, and total leaf area ofC. acuminata seedlings all showed highest values at the planting density of 25 plants·m⁻². CPT content in young leaves was higher than that in other organs of seedlings and presented an obvious change with the variation of planting densities and with the highest value at density of 100 plants·m⁻², while for other organs no significant variation in CPT content was found with change of planting density. The accumulation of CPT was enhanced significantly at the planting density of 25 plants·m⁻². It is concluded that for the purpose to get raw materials with more CPT fromC. acuminata, the optimal planting density ofC. acuminata seedlings should be designed as 25 plants·m⁻².

Experiment on ultrasound-associated extraction of seed oil of Korean pine (Pinus koraiensis) was conducted in Northeast Forestry University, Harbin, China. The factors affecting extraction yield, such as ultrasonic frequency, extracting temperature, extracting time and the ratio of material to liquid (ratio of Korean pine seed to absolute alcohol), were analyzed under specific condition and the optimal extracting parameters were obtained as the ultrasonic frequency 32 000 Hz, the extracting temperature 80°C, the extracting time 50 min, and the ratio of material to liquid 1: 30. The study demonstrates that ultrasound is a reliable and great efficiency tool for the fast extraction of Korean pine seed oil.

Bamboo forest is an important forest type in subropical and tropical areas. Due to its biological characteristic and growth habits, bamboo is not only an ideal economic investment that can be utilized in many different manners but also has enormous potential for alleviating many environmental problems facing the world today. This review describes ecological functions of the bamboo forest on soil erosion control, water conservation, land rehabilitation, and carbon sequestration.

The Sanjiang Plain is a vast area of alluvial floodplains and low hills in northeast Heilongjiang Province. It is the largest tract of wetlands in China and East Asia outside of Siberia. 28 wetland nature reserves exist on the Sanjiang Plain, and three of them have been listed as wetlands of international importance to water bird conservation by the Ramsar Convention Bureau. The wetlands of Sanjiang Plain are noteworthy for its rich biodiversity, but they continue to decline in area and deteriorate in quality currently. The main threats or constrains, immediate cause, root cause and required response are analyzed in this paper, and the four aspects opinion such as improvement of watershed management, enhancement of protection and restoration of habitats and biodiversity, alternative livelihoods of rural residents living in and near natural wetland reserve, and reinforcement of capacity building of natural reserves are brought forward as the effective measures for the Sanjiang Plain wetland protection.

Terpenes, aldehydes, ketones, benzene, and toluene are the important volatile organic compounds (VOCs) emitted from wood composites. A sampling apparatus of, VOCs for wood composites was designed and manufactured by Northeast Forestry University of China. The concentration of VOCs derived from wood based materials, such as flooring, panel wall, finishing, and furniture can be sampled in a small stainless steel chambers. A protocol is also developed in this study to sample and measure the new and representative specimens. Preliminary research showed that the properties of the equipment have good stability. The sort and the amount of different components can be detected from it. The apparatus is practicable.

A newly drying technology, intermittent-contact drying of veneer with flexible screen belt (lCD-fbs), was invented and used in poplar veneer drying. Productive test was carried out for validating the practical use of this drying method. The test result shows that to dispose flexible screen belts on the two sides of hot board could help steam discharge remarkably. The veneer dried using ICD-fsb method had smooth and level surface, less deformation and warping, even moisture content, and high utilization rate. The time for opening hot board to discharge steam, which, early or late, is a key to obtain good dyring result, was determined at the time when the core's temperature of veneer reaches 100°C (vaporization). Using ICD-fsb method, the shrinking rates in tangent of veneer were from 1.90% to 2.26% for veneer of 0.4 mm in thickness, 2.49% to 4.50% for veneer of 1 mm in thickness and 1.34% to 3.30% for veneer of 1.7 mm in thickness, which are much lower than the results obtained by other drying methods. The method of ICD-fsb offers a reliable technological guarantee for solving the deformation problem of veneer drying, especially the deformation of wood from quick-growing plantation.

The experiment on control ofLymantria dispar L by using different kinds of biological measures, including nuclear polyhedrosis virus (NPV) ofLymantria dispar L., BtMP-342, sex-attractant as well as botanical insecticide, was carried out in the forest regions of Inner Mongolia in 2003. Two concentrations (2.632×10⁶ PIB·ml⁻¹ and 2.632×10⁷ PIB·ml⁻¹) ofLymantria dispar L. NPV were sprayed on the 2rd-instar-larvae ofL. dispar and 70% and 77.8% control effect were obtained respectively. BtMP0-342 was applied to the 3rd- and 4th-instar larvae and the control effect was around 80%. The sex-attractant provided by Canada Pacific Forestry Research Center also showed a good result in trappingL. dispar adults. The self-produced botanical insecticide, which was extracted from a kind of poisonous plant distributed in Daxing'an Mountains, China, exhibited a good control result in controlling the larvae ofL. dispar, and 82% mortality was observed when spraying primary liquid of the botanical insecticide on the 3rd–5th-instar-larvae in lab.

The air microbial species and quantities in a wood mill in Harbin, China were measured using sedimentation plate method. Results showed that the microbial quantity in the air at the workshop without depurator (54939 cfu·m⁻³) was 2.1 times that of the workshop with depurator (25768 cfu·m⁻³). The depurator could purify air microorganisms at the workshop, with a purifying rate of 53.1%, but it did not reach the standards of clean air. Comparatively the depurator is effective in reducing the quantity of air actinomyces, and some kinds of air actinomyces, such asScabies, Cinereas andHygroscopicas, can be clean out, but it is not very effective to bacteria and fungi. It is suggested that more effective and feasible methods should be developed for purifying air microorganisms at the workshop in the future.