Phyllostachys edulis forests and soil in their central distribution area in subtropical China were selected as research object. This study discussed the effects of productivity level (Ⅰ: 30 000±1 000 kg·hm^-2a^-1; Ⅱ: 34 000±1 000 kg·hm^-2a^-1; Ⅲ: 37 000±1 000 kg·hm^-2a^-1; Ⅳ: 42 000±1 000 kg·hm^-2a^-1; Ⅴ: 47 000±1 000 kg·hm^-2a^-1) on the distribution of carbon (C), nitrogen (N) and phosphorus (P) and their stoichiometric characteristics of Phyllostachys edulis and soil by comparing C, N and P content of Phyllostachys edulis and soil, and their stoichiometric characteristics, which could provide theory evidence for long-term productivity maintenance in Phyllostachys edulis forests. The result showed that the productivity level had less effect on the distribution of plant C and P in different organs, and had more effects on N distribution. The difference of the distribution pattern of C and P of each organ in different productivity levels was not significant, except leaf C (P<0.01). Except bamboo stem, N distribution pattern in different organs in different productivity levels reached a highly significant level (P<0.01). The productivity levels had less impact on the stoichiometry of plant C:N, C:P and N:P, the difference in different productivity levels did not reach a significant level. Stoichiometry of main nutrients in Phyllostachys edulis forests was inherently stable, in line with "internal stability hypothesis". The productivity levels had significant impact on soil C, N, P, hydrolyzable N and available P, soil C:N, C:P, N:P, H-N:A-P reached a highly significant level in different productivity levels (P<0.01). When N:P < 14, the forests was mainly limited by N. In this study, soil N:P was 4.50-13.89, indicating Phyllostachys edulis forests in research area was mainly limited by N, rather than P. N:P decreased with the increase of productivity level, soil N:P was index to represent Phyllostachys edulis forests degradation succession process. Analysis the correlation between stoichiometry value of main nutrient of plant and soil indicated no significant level between the two.

The low-quality forest community stability was comprehensively evaluated by calculating subordinate function values of a model which was established based on fuzzy synthetic evaluation by a total of 30 factors of 5 indices of species diversity, soil physical properties, soil chemical properties, litter characteristics and soil carbon flux in 5 typical low-quality forest stands that mixed conifer and broadleaved forest, Populus davidiana forest, Quercus mongolica forest, Betula platyphylla forest and broadleaved mixed forest in the Greater Higgnan Mountains. The results showed that: The indices of species diversity, litter characteristics and soil carbon flux of mixed conifer and broadleaved forest are highest, the index of soil chemical properties of broadleaved mixed forest is highest, the index of soil physical properties of Quercus mongolica forest is highest, forest community stability of 5 types of forest communities in the Great Higgnan Mountains, ranked in the decreasing order of community of mixed conifer and broadleaved forest>broadleaved mixed forest>Quercus mongolica forest>Betula platyphylla forest>Populus davidiana forest. The evaluation results can provide theoretical basis for the ecosystem restoration of low-quality forest stands in the Greater Higgnan Mountains.

Three representative forest gaps were selected as experimental plots in Pinus koraiensis coniferous and broad-leaved mixed virgin forest in Liangshui National Nature Reserve, Dailing District, Yichun, Heilongjiang Province. Sampling points were set up by the grid method, the contents of soil particulate organic carbon (POC) and mineral-associated organic carbon (MOC) in surface soil layer (0-20 cm) were periodically measured from June to October during the growing season. Spatiotemporal heterogeneity of POC and MOC were analyzed by the methods of traditional statistics and geostatistics. The results showed that: soil POC and MOC changed significantly over months. Both of them roughly exhibited the following tendency, i.e., first increasing, then decreasing, after obviously increasing, but the change of MOC lagged behind the change of POC; Both of soil POC(coefficient of variation ranged from 50.5% to 94.4%) and MOC(coefficient of variation ranged from 21.0%to 61.0%) had spatial heterogeneity, their variability fell into moderately spatial variability; Variance analysis showed that month had highly significant influences on soil POC and MOC(P<0.01). The forest gap size had highly significant effect(P<0.01) on the former, but no significant impact on the latter(P>0.05); According to the proportion[C/(C₀+C)], both of POC and MOC had strongly spatial autocorrelation that was mainly caused by structural factors; Contour maps indicated that POC and MOC in surface soil layer had the characteristics of patchy or continuous distribution; Soil POC was lower in the forest gap center or near the center, patchy distribution was relatively obvious. The distributions of MOC were more even than that of POC, and low-value centers mostly distributed on the edge of forest gaps; The spatial distribution pattern of MOC over different months was relatively stable compared with that of POC.

The carbon density characteristics of two common types of shrubs (including Spiraea pubescens shrub and Corylus heterophylla shrub) were studied in the paper,which are distributed in northern mountain region of Hebei province. The results showed that Spiraea pubescens shrub was higher than Corylus heterophylla shrub in both the carbon density of every parts and total carbon density. The biological carbon density, litter carbon density, soil organ carbon density and total carbon density of Spiraea pubescens shrub were 5.91,0.23,54.31 and 60.44 t·hm^-2,and those of Corylus heterophylla shrub were 12.81,1.38,141.08 and 155.27 t·hm^-2. The biological carbon density of Spiraea pubescens shrub was lower than the average carbon density of shrub communities of China which was 10.88 t·hm^-2, and that of Corylus heterophylla shrub was higher than that. The total carbon density of Spiraea pubescens shrub was lower than that of Larix gmelinii forest,Populus davidiana forest, Betula platyphylla forest, Quercus mongolica forest and Pinus tabulaeformis forest, and the total carbon density was lower than that of Larix gmelinii forest,Populus davidiana forest, Betula platyphylla forest,and higher than that of Quercus mongolica forest and Pinus tabulaeformis forest. It was concluded that there is significant difference among various shrubs, and there is a bigger carbon density in the shrubs under better site conditions and free of disturbance for long time and the carbon density of shrubs should be considered when the carbon density is evaluated in regional scale, moreover, in order to enhance carbon sequestration of vegetation, some measurements should be carried out to lead a succession from shrubs to forests. Shrubs might be regarded as complementary for forests in carbon sequestration in temporal and spatial aspects.

Allometric biomass equations are widely used to predict above-ground biomass in forest ecosystems. It found the distribution of the parameters a and b of the allometry between above-ground biomass (M) and diameter at breast height(D), lnM=a + blnD, well approximated by a bivariate normal from analysis a data of 304 functions of 80 papers. ANOVA was tested to parameters in seven genera. In contrast to the parameter a, there was significant difference in parameter b. There were negative correlation between the parameter a and b, the parameter b and latitude. From this negative correlation, simultaneous-equation was used to build general model for parameters which were changed by latitude. Three methods which include established general model, minimum-least-square regression and Bayesian approach were used to fitting the above-ground biomass of Larix kaempferi in sub-tropical alpine area. The result showed that general model was the lowest precise quantifications(R²=0.892), but it could estimate the biomass where forest situated in latitude without samples. With sample size was more than 50, both Bayesian method and minimum-least-square regression was no significant difference in the mean absolute error. And it was less than 50, Bayesian method was better than minimum-least-square regression. Therefore, it was suggested that Bayesian method was used to estimate above-ground biomass when the sample size was less than 50.

So far, the approaches of nonlinear seemingly unrelated regression (NSUR), nonlinear adjustment in proportion (NAP) and nonlinear simultaneous equations (NSE) have been proposed to establish compatible biomass models. However, to our knowledge, systemic comparison of these methods is not studied. Therefore, the three methods NSUR, NAP and NSE were compared based on predictive accuracy using 150 masson pine (Pinus massoniana) biomass data in this study. Two alternative approaches, controlling jointly from level to level by ratio functions and controlling directly under total biomass by proportion functions were considered for the two approaches of NAP and NSE. Six candidate tree variables of diameter at breast height, tree height, ground diameter, age, under branch height and crown width were evaluated for their contribution to biomass models improvement. Single variable, bivariate and multivariate (three variables) biomass models were established based on the first three of the most significant tree characteristics. Heteroskedasticity in the biomass models was removed by weighted least square regression. Compatible biomass models were established and estimated based on single variable, bivariate and multivariate using NSUR, NAP and NSE. The results showed that the three analyzed methods could ensure efficiently that components of biomass added up to the total biomass with high prediction accuracy. However, overall, NSE had the highest prediction accuracy and most stable, following by NSUR, and NAP was the worst. For balancing the model prediction accuracy and survey cost, the NSE of controlling directly under total biomass with diameter at breast height and height as stand variables was proposed to construct compatible biomass model at considering or no considering stand origin situation based on the systemic comparison of modelling and validation data sets.

To build an efficient axillary bud multiplication system of Acacia mangium × A. auriculiformis, the aseptic plantlets of A. mangium × A. auriculiformis were used to screen the optimal protocol for in vitro multiplication. The optimal multiplication medium and period, length of the sterile stems, subculture times, rooting and transplant survival rate were studied. The results showed that after being cultured 7 times on improved-MS+ 0.5 mg·L^-16-BA+0.1 mg·L^-1 NAA +0.04 g·L^-1Ac(with combination of 3% sugar and 7 g·L^-1 agar),which was the best multiplication medium screened from the trial test, the average proliferation times of the stem with one axillary bud were 2.52, and the propagation coefficient of the plantlet was around 14.99 after 35 days. Moreover, the plantlets grew well and there was no obvious variation of the multiplication ratio. The aseptic stem with 2 or 3 axillary buds was inoculated to 1/2MS +IBA1.0 mg·L^-1+NAA0.5 mg·L^-1(with combination of 3% sugar and 7 g·L^-1 agar)for rooting culture, the rooting rate was 96.5% in 15 day and the transplant survival rate was 95.0%.

The genetic diversity and genetic structure of four natural populations of Taiwania cryptomerioides were investigated using inter-simple sequence repeat (ISSR). Of the 100 primers screened, 10 primers were selected and they generated 78 stable and distinct bands, among which 61 bands were polymorphic. The result of POPGENE indicated that T. cryptomerioides had a medium level of genetic variation at the species (the percentage of polymorphic bands PPB=78.21%, Nei's gene diversity H=0.249 4, Shannon's information index I=0.377 8) and population levels (PPB=52.56%, H=0.178 3, I=0.267 7). There was to a certain level genetic differentiation among four populations (G_ST: 0.285 1; Shannon's genetic differentiation: 29.14%; AMOVA genetic differentiation: 28.31%), and most of the genetic differentiation occurred within populations. The UPGMA clustering and Mantel test showed that there was no significant correlation between the geographical and genetic distance(r=0.043 3, P=0.435 6). Based on these findings, we propose appropriate conservation strategies for this endangered species.

A plant growth-promoting rhizobacterium (PGPR) was screened from plant rhizospheric soil by the bioassay methods of wheat leaf green retaining and radish cotyledon growth and isolated, and then, the PGPR was identified with molecular biology means. A pot experiment of Platycladus orientalis was conducted with controlled water supply (control, light drought stress, moderate drought stress and severe drought stress) and the PGPR was inoculated. Effects of the plant growth-promoting rhizobacteria on dry weight, antioxidant enzyme, and endogenous hormone of P. orientalis was studied in the present research. According to the morphologic characteristics, physiological biochemical properties and phylogenetic analysis of 16S rRNA genes, the PGPR isolated in the present study was identified as Bacillus cereus. Under well-watered conditions, there was little effect of PGPR inoculation on antioxidant enzyme, osmotic adjustment substance, and lipid peroxidation products of P. orientalis. Under drought stress conditions, B. cereus inoculation increased the antioxidant enzyme activities. However, osmotic adjustment substance, and lipid peroxidation products were decreased as a result of PGPR inoculation. Regardless of the water status, the contents of indoleacetic acid, gibberellins, and zeatin in P. orientalis were significantly increased as a result of B. cereus inoculation. Besides, PGPR decreased abscisic acid content by 23.81% under severe drought stress. The dry matter accumulation of P. orientalis was significantly improved due to B. cereus inoculation. Additionally, B. cereus inoculation promoted shoots dry matter accumulation of P. orientalis, however, it had a decreasing effect on roots dry mass accumulation with the increasing drought intensity. The results suggest that B. cereus inoculation could effectively alleviate the damage of drought stress to P. orientalis by regulating the antioxidant enzyme and osmotic adjustment substance, and stimulating some endogenous hormone production. In summary, PGPR inoculation could improve drought resistance of P. orientalis, and improve the shoot dry matter accumulation, and it would be a supplementary measure for afforestation in arid and semi-arid environment.

In this study, the daily changes of antioxidant enzyme activities,the contents of malondialdehyde (MDA) and osmoregulation substances were measured in leaves of Salix gordejevii, Artemisia halodendron, Melissitus ruthenicus, Salsola collina, Agropyron cristatum, Caragana microphylla, and Lespedeza bicolor in different family and genera grown respectively in natural habitats of Hulunbuir desert and Songnen desert. The results showed 1) Among 7 species of psammophytes, the maximum value of average daily MDA content was higher 2-3 times than the minimum one; the maximum value of average daily activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) was respectively higher 2.2, 7.5 and 2.5 times than the minimum one; the maximum value of average daily contents of proline, soluble protein and soluble sugar was respectively 35 times, 1 times and 2 times than the minimum one. 2) S. collina and A. halodendron had not only lower average daily content of MDA, but also lower average daily activities of SOD, POD, and CAT, and lower average daily contents of proline, soluble protein and soluble sugar. While, M. ruthenicus and C. microphylla had higher average daily content of MDA and activities of POD and CAT, and higher average daily contents of proline, soluble protein, indicating that the degree of membrane lipid peroxidation was positively correlated with antioxidant enzyme activity and osmoregulation substance contents. 3) In terms of kinds of osmotic adjustment substances, leguminous plants depended on proline, while S. gordejevii and A. cristatum depended on soluble sugar. In terms of kinds of antioxidant enzymes, M. ruthenicus, C. microphylla and A. cristatum hinged on CAT and POD; while, S. gordejevii and L. bicolor required for SOD. This study suggests that 7 species of psammophytes would keep higher activities of antioxidant enzymes and contents of osmotic adjustment substances to inhibit lipid peroxidation and maintain cell oxygen free radical metabolism balance to adapt to desert environment.

In an effort to determine the optimal nitrogen application rate for Xanthoceras sorbifolia, a series of pot trials were conducted to investigate the effects of different nitrogen application rates on the growth and photosynthetic characteristics of the species. Five nitrogen levels of 0 (N₀), 130 (N₁), 180 (N₂), 230 (N₃) and 280 (N₄) mg·seedling^-1 were applied with five replications. Fertilization in the form of urea was applied once a week and 12 times throughout a single growing season; the amount of fertilizer was the same in each nitrogen application. The results showed that N fertilizer was able to significantly improve growth indicators of seedlings in each period. N and P nutrient content of leaf in growing season of N₃ treatment increased by 13.64% and 60.97% compared with the controls. Dynamic accumulation of dry matter, N, P, K nutrient accumulation, and N nutrient content of root and leaf by the end of growing season increased by 42.70%, 27.43%, 7.71%, 105.36%, 77.55% and 38.83% compared with the controls. Photosynthetic characteristics in N₃ treatment were best, and total root biomass, volume and specific root length in N₃ significantly increased compared with other treatments. N₁ treatment promoted P absorption, and the P nutrient content of leaf in growing season was from 22.77% to 74.39% higher compared with other treatments. Taking into account other factors, the best application of N for X. sorbifolia seedlings was from 230 mg·seedling^-1 to 280 mg·seedling^-1.

In this paper, a southern fresh jujube, Zhongqiusucui, used in a comparative study on the growth period, leaf area and photosynthetic efficiency of lignified bearing shoot and non-lignified bearing shoot. The results showed that: 1) The growth period of lignified bearing shoot was longer than that of non-lignified bearing shoot. 2) The leaf area of lignified bearing shoot was significantly larger than that of non-lignified bearing shoot. 3) The net photosynthetic rate of lignified persistent bearing was higher than that of non-lignified bearing shoot. Under the strong light condition, lignified bearing shoot still maintained high photosynthetic rate. 4) Anatomy showed that the cell density of the palisade tissues of lignified bearing shoot was greater, and the conducting tissue of stem was stronger than that of non-lignified bearing shoot. 5) The chlorophyll a/b ratio of lignified bearing shoot was significantly greater than that of non-lignified bearing shoot. By comprehensive analysis on the comparison between lignified bearing shoot and non-lignified bearing shoot, the lignified bearing shoot had advantages in growth period, leaf area and photosynthetic efficiency, all of which indicate the lignified bearing shoot should have higher accumulation ability of photosynthetic product.

How to select appropriate target tree species used for constructing typhoon- and frost-resistant plantations is one of challenges in afforestation practice in the mountains area along coast. In this study, the typhoon- and frozen-damaged plantations of Cryptomeria fortunei in each of sloping face and concave slope area were reconstructed by planting functionally target-oriented tree species in Pan mountains of Tiantong region, Zhejiang province. Those tree species were selected based on their functional traits, including the strength in mechanical and frozen resistance. Variation in growth of functionally target-oriented species and forest structure were investigated after 7 years of site reclamation. The results showed that Cyclobalanopsis gracilis, Cyclobalanopsis gilva, Cyclobalanopsis myrsinaefolia, and Schima superba had strong ability of blizzard- and frost-resistance. Within the re-built plantations, the sub-tree layer was formed by the functionally target-oriented species with 5-6 m in height and above 15% in coverage; in the shrub layer, the height and coverage approached 2-4 m and 70%, respectively. The comprehensive importance value of the functionally target-oriented species was above 50% and 70% respectively in tree and shrub layer. Compared with the reference site, the growing stock increased 51.8% and 59.6% respectively in sloping face and concave slope area. In conclusion, the blizzard- and frost-resistant plantations constructed with the functionally target-oriented species quickly developed to multiple layers in community structure, and remarkably increased growing stock, thus, improved effectiveness of forest defense against typhoon- and frozen-induced stresses.

Large-area Cupressus funebris pure forests constructed for protection forests in Yangtze are a major forest type in hilly area Sichuan Basin, but are one of the two major low efficiency stands in Sichuan due to reasons. The plantations were reconstructed with planting different plant species in 2002.In this study, 6 planting patterns were selected to compare their soil anti-erodibility. The study area was located at Jingyang District, Deyang City, Sichuan Province. The experiment of soil anti-erodibility in different vegetable patterns was conducted in December 2010. The main results were: 1) There was significant influence of the reformation on soil physical properties, soil organic matter contents, fine root contents and water stable aggregates (P<0.05). Soil physical properties in BZQ were the best and those in CZ were the worst. The soil organic matter content was in the order: BZQ> BZ> BL> CB> LZ> CZ; the fine root contents were in the order: CZ> BZQ> BZ> CB> BL> LZ; water stable aggregates were in the order: BZQ> BL> BZ> CB> CZ> LZ. 2) Principal component analysis indicated that the sequences of soil anti-erodibility and water stable aggregates contents were fully consistent; the water stable aggregates were the largest contribution (58.93%) to the soil anti-erodibility in all parameters. Moreover, stepwise regression demonstrated that the comprehensive evaluation value was Y=97.236+1.889 X₅(P<0.01,R²=1.00). Comprehensive analysis of the above parameters showed that BZQ enhanced the ecological functions of C. funebris forests in Sichuan hilly area; consequently, BZQ was the best planting pattern among five patterns studied. This study suggests that the pattern selection is very important, and clearcutting should especially be careful. The appropriate pattern could improve soil corrosion resistance and reduce soil erosion, whereas improper patterns would exacerbate soil erosion.

To explore the pathogens of branch blight of Acer palmatum ‘Sangokaku’ in Zhejiang province,The infected samples were collected from Siming mountain area of Zhejiang in September 2013. The pathogens were isolated by tissue isolation method from blighted A. palmatum‘Sangokaku’ branch and cultured on standard medium. The obtained colonies were identified as Colletotrichum according to the taxonomic system of Sutton B C after being subcultured and single hyphal fragment. The results showed that the six isolates were obtained from the sampling sites. Their conidia were cylindrical, colorless single spore, with one oil ball, blunt ends, ranged from (18.23-11.76) μm × (4.46-2.94) μm (average 14.79 μm × 4.06 μ m). The appressoria were nearly round or irregular in shape, edge smoothing, pale brown, average 8.67 μm × 4.52 μ m. Conidia and appressoria were similar with Colletotrichum gloeosporioides in shape and size. Pathogenicity tests were performed by strain Z920121. After inoculation, the same branch blight was observed in 23 days on 100% of inoculated branches. DNA was directly extracted from the mycelium of Z920121 grown on PDA for 10 days. The identities of the isolates were confirmed by ITS1-5.8S-ITS2 rDNA sequence (GenBank Accession No. KF787111) analysis that showed 100% sequence similarity to C. gloeosporioides. (Accession No. KC493156.1,HQ645082.1). It was identified that the pathogen of branch blight of A.palmatum ‘Sangokaku’ in Zhejiang province was C. gloeosporioides. Treatment by spraying the plant with 40% EC 800-times diluted prochloraz liquid had a control effect on the disease up to 92.6%.

Based on the previous researches on management willingness of farmers and collective forest property right system reform (CFPRSR) performance, this study used Yong'an of Fujian as a case to conduct the performance comprehensive evaluation through building performance evaluation index of CFPRSR with analytic hierarchy process (AHP). Afterwards, the performance of CFPRSR was used as an impact factor to analyze its influence on farmers' will of forest management by constructing binary logistic model. The results showed that the comprehensive score on the performance evaluation of CFPRSR was 0.801, which indicated that Yong'an had an obvious performance, and the performance of CFPRSR had a relatively significant impact on farmers' forest management. The research results could provide scientific and theoretical guidance to the implementation of CFPRSR, which is helpful to stabilize the existing accomplishment, and the sustainable development of CFPRSR.

The resin yield and rosin components of Tongmian and Gupeng provenances of Pinus massoniana were compared respectively in the 6-, 8-, 10-, 12-, 15- and 20-year-old stands. The results showed that the resin yield of Tongmian was lower than Gupeng at the all ages, however the mature time of resin yield was about 4 years earlier than Gupeng's. The contents of resin acids, abietic resin acids, Hawasong type resin acids, dehydroabietic acid and the resin acid oxide were used as comprehensive evaluation index, by which the rosin quality of Tongmian provenance was higher than Gupeng's. The rosin quality of Tongmian and Gupeng reached to the highest when the trees were 10-year-old and 20-year-old, respectively. Based on the results, the Tongmian would be suitable to a short rotation used for resin production or timber and resin production stands. Resin tapping can be started at the 7^th to the 10^th year and felling can be conducted at the 17^th year. However, the Gupeng would be suitable to a long rotation. The tapping time is better to start during 11- to 15-year-old and the final felling can be conducted at 26 years old.

In this paper, the growth, wood basic density, diameter distribution and structure stability of Schima superba plantation were investigated in 12 sample plots with different biotopes, operating measures and ages in Nanping and Sanming city of Fujian province. Results showed that, the average tree height, diameter at breast height (DBH) and individual volume of stand in shady slope were significantly larger than that of plantation in sunny slope; The tree growth, especially in DBH and individual volume of stand, in lowerslope was obviously greater than that in the middleslope and the upperslope; The average tree height of the stand increased with initial planting density; However, DBH and individual volume displayed converse trend with increase of planting density; Growth of the plantation gradually increased with stand age; Average individual volume of trees at 29 age was over 4 times greater than of trees at 13 age, and the 46-year-old stand still grew fast. There were no significant differences in wood basic density between different aspects of slope; However, the wood basic density in upperslope was significantly greater than that in middleslope and lowerslope; The wood basic density was relatively greater when the initial spacing was set at 1 667 plants per hectare; The greater or less stand density significantly reduced the wood basic density and hence wood properties; Wood basic density progressively reduced with the forest age and the varied pattern met with the variation type of Pashin Ⅲ. Differentiation in height and diameter growth and wood basic density of the plantations with the same age in the same direction and position of slope was relatively small. But the initial stand density obviously affected growth. The smaller the initial planting density the greater the variation in diameter was. The diameter distribution of S. superba plantation in different habitats (slope, position of slope), with forest management measures (initial stem-numbers) and ages was well fitted to the cumulative distribution function of Weibull distribution; The diameter distribution exhibited a reverse "J" type, suggesting the stands had a stable structure with reasonable competition and strong adaptability. The class Ⅱ and Ⅲ were the main trees in the stands according to tree classification, which also lent support that the structure of the plantations was stable. Thus, a suitable site and stand density should be selected according to the goal of cultivation. For example, forestation for large diameter of S. superba the plantation should be conducted on the shady slopes, lowerslopes and initial planting density should be 1 667 stems per hectare. Although the structure differentiation of the plantation is not obvious, appropriate thinning and density control should be applied for large diameter timber.

Based on the data of the national continuous forest inventory from 2008 to 2013, single tree biomass of larch forest in northeastern China was estimate using biomass compatibility model of different tree species, and summed to plot biomass. Biomass expansion factor (BEF) was calculated to estimate forest biomass, and then biomass was transformed into carbon storage with carbon concentration. With the inventory statistics, carbon storages of provinces at different stages were summarized. The results indicated that: 1) vertical distribution of biomass for larch organs was: stem (48.11%)> root (23.04%)> branch (16.15%)> bark (7.2%)> foliage (4.76%), aboveground biomass made up 76.9% of the total, and root/shoot ratios were raised by age groups. 2) BEF values of larch field plot were reducing by age groups, around an average level of 0.95. 3) total carbon storage of northeastern China was 167.5×10⁶t, based on mid-aged forest, which accounting for 44.22%, the maximum carbon density of mature forest reached to 55.22 t·hm^-2, and the mean value of all age groups was only 37.06 t·hm^-2, both were far below to the national average. 4) Heilongjiang province carbon storage as 128.35×10⁶ t took the largest percentage of 76.63%, all three provinces had virtually equal carbon density, which increased with age group, but grew slower after near-mature stage.

This article mainly studied the influence of sugar content of ammonium lignosulfonate on the physical and mechanical properties of binderless medium density fibreboard. The purified ammonium lignosulfonate was prepared by alkali-solution and acid-isolation. The two different binderless medium density fibreboards (OLF and PLF) were produced with wood fiber as basic phase and original ammonium lignosulfonate (OL) and purified ammonium lignosulfonate (PL) as filler by flat-press process. The phenol-sulfuric-acid method was used to determine the sugar content. The chemical composition, degree of crystallinity and microstructure were characterized by fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. The results showed that the sugar content of OLF was 22.38%, while the sugar content of PLF was 13.37%. The physical and mechanical properties of OLF were better than that of PLF. The result of FTIR showed that hydroxyl of PLF decreases obviously, which was that it didn't help the forming of hydrogen bond. The XRD result showed that the relative crystallinity of OLF is higher than that of PLF. The SEM showed that the components of the OLF distributed uniformly, and combined closely among wood fiber.These results told that the binderless medium density fibreboard with ammonium lignosulfonate with higher sugar content as binder possessed better physical and mechanical properties.

Algorithms which were available in most literatures for whole layout of large scale rectangular parts gave solutions that resulted in frequent change of saw line and therefore dropped sawing velocity down. To solve this problem, a grouping and dimension-reducing heuristic rule which took areas of rectangular parts as priority was put forward in this paper. According to this rule, no more than three kinds of rectangular parts were considered in each layout calculation. Corresponding mathematical model was set up. Hybrid punishment function that was the combination of interior point method and exterior point one was applied to deal with constrains. Genetic algorithm (GA) was adopted to search global optimal solution for layout. It was proved by example that the algorithm used in this paper could provide layout solution which exactly fulfilled guillotine cutting requirement and had saw line in order and therefore was useful to increase of sawing efficiency.