[Objective] The ability of maintaining hydraulic structure and carbon balance is a key factor for plants to affect the survival and recovery from drought under drought stress. The main purposes of this study were to explore the interaction of hydraulic failure and carbon starvation on black locust(Robinia pseudoacacia) seedlings by monitoring the changes of hydraulic traits and nonstructural carbohydrates (NSC) reserves during drought and rewatering periods, with a particularly interest in the seedling's performances during the rewatering period after experiencing severe drought stress to explore the major factors limiting leaf recovery from drought. Results can illustrate the interaction pattern of hydraulic traits and carbon metabolism during drought and rewatering periods, meanwhile provide research idea and experimental evidence for revealing physiological mechanism of decline and die-off for black locust in arid and semi-arid region.[Method] We measured predawn and midday twig water potential, midday branch percentage loss of conductivity (PLC), net photosynthetic rate, stomatal conductance, leaf area of individual plant, and NSC concentration of branches and roots after drought-induced severe defoliation and with having regenerated leaves after rewatering. Stem vulnerability curve after severe drought was determined. Leaf area, specific leaf weight and net photosynthetic rate of leaves resprouting on stem base and top after rewatering were compared. Predawn and midday twig water potential, and midday PLC of branches resprouting on stem base and top after rewatering were also compared. [Result] At the time of drought-induced complete defoliation, predawn and midday twig water potential were -3.01 MPa and -3.73 MPa respectively, and they were significantly lower than those of control. The midday PLC defoliated seedlings reached to 91%, and was significantly higher compared to control. At the time of more than 90% leaves defoliation, leaf net photosynthetic rate was negative with near-zero of stomatal conductance. Midday branch PLC was 81% in 30 days after rewatering, still significantly higher than that of control. P₅₀ (the water potential causing a 50% conductivity loss) was -1.09 MPa for branches subjected to drought and rewatering, which was 0.37 MPa higher compared to control. Cavitation resistance in branch segments was significantly reduced by drought. NSC concentration in branches and roots markedly declined during drought and rewatering periods, and NSC concentration dropped more severe during rewatering. Total leaf area per individual resprouting plant was only 38% of the control. Leaves resprouted mainly on stem base and top, but leaf area, net photosynthetic rate and stomatal conductance of leaves on stem base was significantly greater than those of leaves on the top. Predawn and midday water potential of twigs resprouting on stem base was also significantly higher than that of twigs resprouting on the top.[Conclusion] Severe drought lowered water potential, increased xylem embolism, and constrained water transport, then reduced photosynthetic rate resulting in negative carbon balances. Severe drought induced cavitation fatigue, and the lowered NSC reserves limited resprouting ability during rewatering period. Reduced NSC reserves may also have impact on instant xylem cavitation repair. The interaction of hydraulic failure and carbon starvation exacerbated the effect of drought on black locust seedlings.

[Objective] This study aimed at obtaining the most suitable container type and size for growing Chinese pine (Pinus tabulaeformis) under sub-irrigation, and thus, the effects of container types and sizes on water consumption and growth of containerized Chinese pine seedlings with bottom infiltration irrigation was studied.[Method] A nest-designed trial was performed on containerized Chinese pine seedlings. There were hard plastic container with sizes of 3.8 cm(cell diameter)×14 cm(length), 3.8 cm×21 cm; non-woven fabrics container with sizes of 4.5 cm×10 cm, 4.5 cm×15 cm; black plastic container with sizes of 10 cm×10 cm, 10 cm×15 cm. All seedlings were infiltration-irrigated at the bottom of containers. Watering amount and frequency, seedling growth, including shoot height, root collar diameter, biomass, taproot length, and root length were measured. [Result] During the irrigation, the watering amount showed non-woven fabrics container > black plastic container > hard plastic container, and the mean values were 1453 mL per seedling, 964 mL per seedling, 442 mL per seedling, respectively. The watering frequency showed non-woven fabrics container > hard plastic container > black plastic container. Hard plastic container had the largest water use efficiency (WUE_i), especially in the long one. Both long and short hard plastic container had shoot height of 15 cm, root collar diameter of 2.6 mm. Also, the shoot biomass of seedlings in hard plastic container was the largest, especially in the long one in which the shoot biomass was 0.4 g. Seedlings in the black plastic container had the largest root biomass, and they were even larger in long black plastic container (0.65 g). The average taproot length in black plastic container was around 23 cm. The shoot height, root collar diameter and biomass of seedlings in non-woven fabrics were all in the lowest level. Seedling quality index (QI) showed black plastic container > hard plastic container > non-woven fabrics container, and the QI of long black plastic container was 2.48. There were no differences in root length, root surface, root volume and specific root length between hard plastic container and black plastic container, but they were all greater than those in non-woven fabrics container.[Conclusion] The most suitable container for growing Chinese pine with bottom infiltration irrigation was hard plastic container which consumed the least water to grow the best seedlings so that the WUE_i was the highest. Black plastic container had also provided large seedlings, but the root was circled. The quality of seedlings in non-woven fabrics container was the worst though it had cost much more water than the other two container types, and the WUE_i of seedlings in non-woven fabrics container was the lowest. Besides, long containers were proved to be good for growing bigger seedlings.

[Objective] In order to reveal the mechanism of increasing salinity tolerance of Elaeagnus angustifolia inoculated with arbuscular mycorrhizal fungi (AMF) and provide theoretic basis for application of the fungi in salinity soil, the effects of AMF on growth and physiology of E. angustifolia were investigated in this research. [Method] The growth effect of E. angustifolia seedlings respectively inoculated with Glomus intraradices (GI) and Glomus mosseae (GM) were determined in four kinds of soil salinity with a potted experiment. Meanwhile, physiological indicators, including photosynthetic characteristics, Na⁺ and K⁺ content, the level of malondialdehyde (MDA) and proline, were detected.[Results] In this experiment, the two AMF were all able to establish symbiotic relationship with E. angustifolia. The colonization rate of G. intraradices was significantly higher than that of G. mosseae. However, mycorrhizal colonization rate decreased with the increasing level of salinity in soil. In addition, the growth of E. angustifolia seedlings inoculated with AMF was significantly enhanced. In moderate salinity stress (total salt 1.56%, pH 9.52), the height of E. angustifolia seedlings inoculated with GI and GM increased by 20.07% and 9.68% than the non-mycorrhizal control, respectively. The dry biomass of mycorrhizal seedlings increased significantly. Besides, AMF significantly increased chlorophyll content and photosynthetic characteristics of E. angustifolia. The net photosynthetic rate (P_n), transpiration rate (Tr), stomatal conductance (G_s), and intercellular CO₂ concentration (C_i) were significantly higher than those of the non-inoculated control (P<0.05). In GI and GM treatments, the activity of SOD, CAT, and POD in leaves were higher than those of non-mycorrhizal seedlings. However, the content of MDA decreased in the roots and leaves of mycorrhizal seedlings. The proline content increased significantly. The Na⁺ concentrations significantly decreased in roots and leaves of GI and GM treated seedlings, but the K⁺ concentrations and K⁺/Na⁺ ratio increased. [Conclusion] Inoculation with AMF could promote the tolerance of E. angustifolia to salinity. The growth and physiological performance of E. angustifolia seedlings inoculated with G. intraradices were significantly better than those of seedlings inoculated with G. mosseae. This research results indicate that G. intraradices has good application prospect in the improvement of saline land.

[Objective] Studies of human-mediated introductions of organisms and resistance of communities to plant invasion has become one of the central issues of invasion ecology. In this study, we explored variation among dominant tree species from different communities in their resistance to exotic plant Rhus typhina. It will help us understanding the mechanisms underlying invasion resistance of plant communities. [Method] Quercus acutissima, Robinia pseudoacacia, Pinus densiflora, and P. thunbergii are common dominant species in hilly reas of Shandong Peninsula. Laboratory bioassays experiments were conducted to evaluate the allelopathic effects of litter leachates from 4 dominant tree species on the germination rate and seedling growth of R. typhina. In soil medium, chemical compounds can function directly or with the help of soil biota. To further elucidate the effects of 4 dominant trees on total biomass and biomass allocation of R. typhina seedlings, pot experiments with litter addition were done in greenhouse in Ludong University. [Result] Our results indicated that compared to treatments with litter leachates from R. pseudoacacia, P. densiflora and P. thunbergii, the litter leachates from Q. acutissima reduced the germination rate and seedling growth of R. typhina in laboratory bioassays. Likewise in pot experiments, the total biomass of R. typhina seedlings was inhibited when treated with Q. acutissima litter. Compared to treatments of the other 3 species, the leaf mass ratio of R. typhina decreased, the root mass ratio and root to shoot ratio increased with Q. acutissima litter addition. [Conclusion] Q. acutissima showed strong inhibitory allelopathic effects on R. typhina. It can be a new way to control the spread of R. typhina by building high resistance plant communities with Q. acutissima. And we could further screen effective allelochemicals from Q. acutissima to control the growth of R. typhina. Our results revealed that the dominant trees exerted different inhibitory effects on the performance of R. typhina, implying that the allelopathy of some dominant trees may play an important role in determining the community resistance to invasion. This study has important theoretical and practical implications for understanding the invasion processes and the risk-assessment and management of exotic plant invasions respectively.

[Objective] The SCARECROW(SCR) gene played important roles in asymmetric cell divisions to generate basic tissues in the root and shoot of plants. The structural features of SCR homologous gene PeSCR in Phyllostachys edulis were analyzed, the tissue specific expression of PeSCR was studied, the influence on PeSCR expression in roots treated with GA₃, ABA, drought and NaCl was investigated respectively, and the function was preliminarily identified by overexpressing PeSCR in Arabidopsis thaliana, which would be helpful to reveal the function of PeSCR and provide genetic resources for molecular breeding of bamboo.[Method] The sequence of SCR homologue gene PeSCR and its upstream regulatory sequence in P. edulis were retrieved from the bamboo database (BambooGDB) using bioinformatics methods. The gene structure was analyzed with Spidey and the acting elements in upstream regulatory sequence were detected using Plant CARE online softwares respectively. The tissue specific expression of PeSCR in different tissues, as well as the changes of PeSCR expression in roots treated with GA₃, ABA, drought and NaCl were analyzed using real-time quantitative PCR (qPCR). The expression vectors of sense and antisense PeSCR were constructed and transformed into A. thaliana, and the phenotype of transgenic plants was investigated to identify the function of PeSCR. [Result] A SCR homologous gene, PeSCR (GenBank No. FP094510) was obtained, the full length of cDNA was 2301 bp, including a 5' untranslated region (UTR) of 238 bp, a 3' UTR of 134 bp and an open reading frame (ORF) of 1929 bp. The genomic sequence corresponding to ORF of PeSCR was 2598 bp containing one intron of 672 bp. PeSCR encoded a protein with 642 amino acids, which had typical domains (LRⅠ, VHIID, LRⅡ, PFYRE and SAW) of GRAS family and belonged to AtSCR subfamily. PeSCR had high homology with SCRs from other monocots, among which the identities with OsSCR2 in rice and AtSCR in A. thaliana were 84.9% and 54.9%, respectively. The regulatory sequence upstream of PeSCR was 1820 bp, including many kinds of responsive elements such as cis-acting regulatory element (AuxRR-core) involved in auxin responsiveness, abscisic acid responsive element (Motif Ⅱb), MYB binding site (MBS) involved in drought-inducibility and light responsive elements, indicating that PeSCR might be regulated by hormones, drought, etc. The qPCR analysis indicated that PeSCR expressed constitutively at a high level in leaf, followed by root and stem, and the least was in sheath. The expression of PeSCR in root was inhibited by GA₃ in short time (within 1 h), but it was induced with prolonged treatment (up to 5 h). Overall, PeSCR was suppressed by exogenous ABA and NaCl, while it was induced initially and subsequently suppressed by drought. The expression of PeSCR in transgenic plants of A. thaliana was confirmed by RT-PCR. The phenotypes demonstrated that sense transgenic plants had a vigorous growth and well-developed root system compared to the wild type, while antisense transgenic plants were small and the growth of root was restrained. [Conclusion] The results indicated that the expression of PeSCR was constitutive in different tissues, and influenced by the GA₃, AAB, drought and NaCl in roots. The expression of sense PeSCR promoted the growth of transgenic plants, while that of antisense inhibited plant growth, suggesting that PeSCR might participate in regulating process of P. edulis growth and development.

[Objective] The Chinese fir(Cunninghamia lanceolata) timber forest in Longquan county of Zhejiang Province was taken as an example to establish a scientific and practical model for appraisal of forest resources assets in order to make the model applicable to appraisal of sub-compartment forest resources, such as mortgage of forest rights, forest insurance, accounting of forest biological assets.[Method] A reference stand was set up and a growth model was developed for the reference stands using production function. The relation between forest prices of the adjacent years was analyzed and used to design the recursive formula for calculating the sequential forest prices. Main factors that influence forest asset value were identified and used to develop assets appraisal model for sub-compartment forest resources assets based on the sequential forest prices. Applicability tests were then conducted for the appraisal model, including significance test of difference between estimated and actual values and accuracy test of the estimation. The recursive algorithm, regression method, and simulation method were used in the process of modeling. [Result] A table of the sequential forest prices of the reference stand was compiled, which objectively reflects the rises of forest values. The adjustment coefficient model parameters of the main factors that influence the forest asset value were fitted. Then the adjustment coefficient empirical equation for sub-compartment skidding distance was given. To mature forest sub-compartment, the adjustment coefficient empirical equations for stand average DBH and stand stock volume per unit area were obtained. The appraisal model of forest resources assets was applied to all sub-compartment appraisal of Chinese fir timber forest in Bajiao village, Yanzhang township, Longquan county. As the outcome of this application example, the forest resources assets list of each sub-compartment was calculated by the appraisal model, the total amounts of the forest resources assets for each farmer household and for the whole village were obtained by summarizing up. The test sample of 98 normal trading examples was used to calculate the test index of the appraisal model, total relative error was -0.16%, mean relative error was 1.25%, absolute value of mean relative error was 8.97%, and estimation accuracy was 97.6%. All the test indicators conformed to the requirements. [Conclusion] The forest resources assets appraisal model based on sequential forest prices was structured, intuitive and understandable, and the evaluation result was satisfactory. The assets appraisal model can be applied in forest resources assets appraisal practices of large number of sub-compartment related to non-transaction forest resources assets appraisals. By using the theory of production function, the matching between input and output in the forest management process of the reference stand was ensured. By using recursive formula, the variation rule of the sequential forest prices in the whole stand growth process can be studied better, and the fusion and mutual verification of 3 methods, the replacement cost method, the income method and the market value method, was realized. By using the age value coefficient, the list of the sequential forest prices of the reference stand can be updated, and the sub-compartment forest resources assets appraisal model can be updated synchronously. The regression models of the main influencing factors of forest price were established, and were better than the simple grading method to deal with the influence factors previously.

[Objective] This paper presents a new forest land type precise classification method based on hierachical classification strategy using high spatial resolution remote sensing image and multi-source auxiliary data in complex mountainous area, which locates in Baihua Forest Farm, Xiaolongshan Forestry Experimental Bureau, Gansu Province.[Method] In the test area, SPOT5 HRG2 and two scenes of GF-1 PMS2 images, ancillary information such as forest resources inventory results, forest form map and forest distribution map, and field measurement sample point data of land cover types and fine forest types were applied in classification process. The multivariate characteristics based on high resolution remote sensing images, including image spectral features, vegetation indices, textural features and image time-phase changed features, and topography characteristics, were used as the significant indicators to develop multi-level information extraction methods and forest type fine identification methods, which were particularly suitable for the complex mountainous terrain area of typical natural secondary forest region in warm temperate zone. Four vegetation indices,including NDVI(normalized difference vegetation index),RVI(ratio vegetation index),RSI(ratio shortwave infrared index)and DVI(difference vegetation index)and six textural features,that is ME(mean),HOM(homogeneity),DIS(dissimilarity),ENT(entropy),ASM(angular second moment)and RK(relative kurtosis)were developed and selected. Three topography characteristic factors related to spatial distribution of major forest types such as DEM elevation slope and aspect were also extracted and used in the hierarchical classification process. Threshold method, support vector machine(SVM), multiple classifier combination(MCC) and artificial neural network(ANN) classification methods were developed and applied in different levels of image. Classification results of different layers were combined into forest types fine classification result map of the whole research area. Finally, independent test samples of seven forest types based on stratified random sampling were selected and the confusion matrix and Kappa coefficient were examined to evaluate the accuracy of classification results. In order to further evaluate the validity of classification method and reliability of classification results on the whole, the performance of the classification method was discussed by comparing the statistic area about five main forest types based on classification results with the statistic results of forest resources inventory and image visual interpretation.[Result] The results showed that the method proposed in this paper had a good performance in forest type information extraction. Overall accuracy of seven forest types, including closed forest land, other types of forest land, nursery land and so on reached 92.28% and overall Kappa coefficient was 0.8996. Average relative accuracy of area statistic results of five main forest types of fine identification, including Pinus tabulaeformis, Pinus armandii, Larix kaempferi, Oak species dominant broad-leaved deciduous forest and other (hardwood species dominant) deciduous broad-leaved mixed forest, reached 92.4%.[Conclusion] The results of this study suggest that the hierarchical information extraction method based on multi-source data support is an effective approach of precise classification of forest land types, fine identification of forest types and accurate monitoring of forest resources, especially in mountainous area of complicated topography conditions. The proposed method in this paper have advantages in fine identification of forest land types with high accuracy and high reliability, and the detail degree of fine identification reaches dominant tree species, which could fully meet the needs of forestry applications such as forest resources investigation, forest land change monitoring and thematic map digital update, etc.

[Obiective] The Chinese pine caterpillar, Dendrolimus tabulaeformis, is a serious native pine defoliator with frequent outbreaks in northern China. The MaxEnt model is one of the most effective software packages available for modeling species' distributions. The main objective of the current study was to test and determine the possibility of using MaxEnt to simulate and predict future large-scale outbreaks of D. tabulaeformis based on county-level historical outbreak records (2002-2011), and daily meteorological data from 19 weather stations in Shanxi province. [Method] Using Principal Component Analysis and Step-wise Regression methods with actual pest outbreak data, the 8 most relevant factors were chosen from 80 outbreak-related bio-climate factors potentially affecting development of the insect. The key factors were X₂₉ (days with mean temperature<5℃ in October), X₄₃ (days with humidity >75% in July), X₅₄ (mean monthly wind speed in March), X₅₅ (mean monthly wind speed in April, May and June), X₅₆ (mean monthly wind speed in July and August), X₆₂ (days with wind speed >10 m·s^-1 in October), X₆₃ (maximum daily wind speed in September), X₆₇ (precipitations in April, May and June). [Result] With the 8 screened phenological factors, the MaxEnt model was used to make the training simulation with the actual disaster data. The Jackknife test showed that X₄₃, X₅₄ and X₅₅ were the three principle climatic factors that best simulated historical outbreaks using the MaxEnt model, and ROC (recevier operating characteristic curve) test showed an AUC (area uner the ROC curve) value of 0.82 with a STD(standard deviation) of 0.019. Based on data from the WorldClim database for future climate scenarios, pine caterpillar outbreak distribution maps for 2050 were generated via the MaxEnt model under RCP(representative concentration pathway)4.5 and RCP6.0. According to these maps, in the 2050s, Beijing and Hebei province, plus the southern border area of Inner Mongolia Autonomous Region with Hebei, will have a high risk of outbreaks under RCP4.5, while more serious outbreak area will be the south central region of Shanxi province under RCP6.0. [Conclusion] MaxEnt model is potentially useful for forecasting future pine caterpillar outbreaks under climate change.

[Obiective] This study was aimed to exam the structure and diversity of intestinal bacteria community from Atrijuglans hetaohei Yang and Dichocrocis punctiferalis Guenee larvae consuming walnut's green husk. [Method] The 16S rRNA PCR-denaturing gradient gel electrophoresis (PCR-DGGE) and the terminal-restriction fragment length polymorphism (T-RFLP) were employed to investigate the characteristics of intestinal bacteria community from the two main pests. [Results] 1)PCR-DGGE showed that the intestinal tract of A. hetaohei larvae had Wolbachia sp., Enterococcus sp., Enterobacter sp., Rhizobium sp. and Pseudomonas sp., with phylotypes of Wolbachia being the predominant group, accounted for 40% of the measured sequence; the intestinal tract of D. punctiferalis larvae had Wolbachia sp., Enterococcus sp., Rhizobium sp. and Pseudomonas sp., with phylotypes of Enterococcus being the predominant group, accounted for 62.9% of the measured sequence. 2)Phylogenetic analysis of the DGGE band revealed that in all the isolated strains, 72.5% of the strains belonged to Proteobacteria, 12.5% to Firmicutes, and 15% to Bacteroidetes in the intestinal tract of A. hetaohei larvae; 37% of the strains belonged to Proteobacteria and 63% belonged to Firmicutes in the intestinal tract of D. punctiferalis larvae.3)T-RFLP data showed 76 bp and 122 bp T-RFs were the predominant groups in the intestinal tract of A. hetaohei and D. punctiferalis larvae, respectively. Principal component analysis (PCA) and cluster analysis indicated that there were two structure categories for the intestinal bacteria communities in A. hetaohei and D. punctiferalis. 4)Both DGGE and T-RFLP analyses showed the diversity differences of intestinal bacteria from A. hetaohei larvae and D. punctiferalis larvae were not significant, and there was a difference in the proportion of bacteria composition. [Conclusion] This study revealed the characteristics of the intestinal microbial composition in two different insects, which provided a theoretical basis for further study on the relationship between the diets and intestinal microbes of the two different diet larvae consuming walnut's green husk.

[Objective] Populus simonii in Shaanxi mainly distributes in northern Shaanxi and in the north Qinling Mt., which are significant differences in geology and ecology. In this study, we carried out a basic research on population characteristics of the endophytic fungi in P. simonii in the two regions to further understand the influence of ecological factors on the geo-ecological distribution of P. simonii. [Method] The leaf samples were regularly collected from the targeted trees at the two different ecological regions, and strictly sterilized on the surfaces before culture. PDA medium and paper culture were implemented to isolate the endophytic fungi from the poplar leaves. The isolated fungi were identified by combinations with the morphology and molecular phylogenic technologies. The population diversity and structure of those endophytic fungi in the poplar leaves were analyzed with the SASS software. [Result] No significant difference of fungal community structure was found between the two distinct sampling regions, Baoji (BJ) and Yulin (YL) with high similar coefficient of 0.4445, and with similar dominant species of dark septal endophytic (DSE) fungi groups, which can be ascribed to the xerotolerant auxology of their host P. simonii. The dominant DSE fungi included Alternaria (RF=23.1%)(relative frequency,RF), Ulocladium (RF=22.5%), Phoma (RF=28.44%). However, the intra-regional similarity coefficients was higher than the inter-regions between BJ and YL, especially in the 3 sampling sites in YL region, whose similarity coefficients was high, ranging from 0.6667 to 0.6897;Inter-region similarity was higher among sites if they had similar host age and understory vegetation, such as Qingyun (QY) site and Yingge (YG) site. The amount, colonized frequency (CF), and RF of endophytic fungal communities in YL region were higher than those in BJ region, however, the Shannon-weiner index (H') of diversity of endophytic fungal communities was reversed. In the all six sampling sites, the index of diversity ranged from 1.53 to 2.62 in a descending order of Fengnan (FN) site, Taochuan (TC) site, YG site, QY site, Hongshan (HS) site and Wuding riverside (WDR), but without significant difference. There were deviations of endophytic fungal community structures between spring and autumn samplings. Total amount and RF of endophytes in autumn were higher than those in spring, but CF and H' were higher in spring than in autumn.[Conclusion] In general, communities of endophytic fungi in the leaves of P. simonii showed host plant specificity; distribution of endophytic fungal communities in the leaves of P. simonii was governed by their host species. The understory vegetation types and the host age also played important roles; however, climate had little effect on the diversity of endophytic fungi communities in P. simonii.

[Objective] In China, there are many iron tailings abandoned nowadays, their ecological restoration has always been the focus of attention. It is well known that the number of soil microbe and the soil enzymes activities are the important indicators of soil biological properties, and also to a certain extent affect the soil fertility. Study on the soil microbial number and soil enzyme activities in iron tailings under different vegetation restoration models can provide scientific basis for the ecological restoration of iron tailings wastelands. [Method] In this study, the soil biological properties of iron tailings under natural restoration and plantation in Qian'an city were targeted, and based on random samples and tracking observations, the soil microbial quantity and soil enzyme activities of different restoration chronosequences in iron tailings were detected and analyzed.[Result] The quantity of soil microbe was increased with the vegetation restoration years, and for the spatial distribution the quantity was decreased with the depth of soil. Of their total quantity, the number of bacteria was the most, followed by actinomyces, and the number of fungi was the least. Plantation had more soil microbial quantity and a higher growth rate than the naturally restored vegetation. After 11 years of restoration, compared with natural restoration, the quantity of bacteria, fungi and actinomyces in 0-20 cm layer of the plantation increased by 14.25%, 80.56% and 75.19%; the quantity of bacteria, fungi and actinomyces in 20-40 cm layer of the plantation increased by 22.78%, 125.80% and 0.51%; and the quantity of bacteria, fungi and actinomyces in 40-60 cm layer of the plantation increased by 8.41%, 145.45% and 55.70%. The soil enzyme activities also increased with the increase of the restoration year, and decreased with increasing soil depth. The soil enzyme activities in plantation were higher than that in natural restoration. After 11 years, compared with natural restoration, the activities of soil catalase, soil invertase, soil urease and soil phosphatase in 0-20 cm layer of the plantation increased by 26.39%, 51.11%, 51.68% and 49.60%; the activities of soil catalase, soil invertase, soil urease and soil phosphatase in 20-40 cm layer of the plantation increased by 23.69%, 5.13%, 19.83% and 46.20%; and the activities of soil catalase, soil invertase, soil urease and soil phosphatase in 40-60 cm layer of the plantation increased by 4.26%, 3.45%, 1.38% and 134.60%.[Conclusion] Vegetation recovery in iron tailings wastelands could improve soil biological properties. Both the natural restoration and plantation could improve the quantity of soil microbial and the activities of soil enzyme in iron tailings, and the improvement effect of plantation was better than the natural restoration.

[Objective] The forest pest disasters are increasing year by year, thus the disaster loss assessment is getting more and more attention by the forestry administrative department and the forestry research department, and it has become hot spot to construct a suitable index system of the forest pest damage assessment. [Method] In this paper, a forest pest damage assessment index system is constructed, including 3 first grade indexes, 14 second grade indexes and 30 third grade indexes, according to the scientific, systematic, hierarchical, feasibility and comparability principles, by using technical and economic approach, replacement cost approach, defensive expenditure approach, market value approach, and willing to pay approach.[Result] The 3 first grade indexes are for direct economic loss, ecological service function loss and social benefit loss. The 14 second grade indexes are for forest economic loss, fruit economic loss,prevention and treatment cost, afforestation and management cost, water conservation loss, soil conservation loss, carbon fixation and oxygen release loss, nutrient accumulation loss, atmosphere purification loss, forest protection loss, biodiversity conservation loss, forest recreation loss, forest culture loss, and non-forestry industry loss. The 30 third grade indexes are for forest stock volume loss, forest growth amount loss, timber grade lower loss, fruit production loss, fruit quality loss, prevention cost loss, treatment cost loss, afforestation cost loss, management cost loss, water adjustment loss, water quality purification loss, soil solidification loss, fertilizer retaining loss, carbon fixation loss, oxygen release loss, accumulation loss of N,P,K,OM, oxygen ion provision loss, pollution absorption loss, noise reduction loss, dust retardation loss, farmland protection loss, pasture protection loss, road drainage protection loss, biodiversity protection loss, recreation environment damage loss, forest culture impact loss, and other related industries losses caused by forest pest disaster. The evaluation index system standardized the meaning and quantitative calculation model of direct economic loss and ecological service function losses by forest pests. For forest recreation loss, forest culture loss, and other related industries losses which are difficult to be quantitative calculate, it could be calculated by the method of willing to pay is used, and the economic loss could also be calculated directly by using the survey method.[Conclusion] This assessment index system can be applied to not only forest pest disaster loss assessment in a region, but also the estimation of losses caused by other disasters, such as forest fire, forest meteorological damage, deforestation. Besides, the quantitative calculation methods of ecological service function losses are equally applicable to the assessment of forest ecological service function. The forest pest disaster loss assessment index system is of great significance for the forest pest control and forest resources management.

[Objective] The physical and mechanical properties of American black walnut were compared among ten strains:Bi (J. nigra ‘Bill 81-143’), LZ (J. nigra ‘Wrights G-4’), PN (J. nigra ‘Peanut’), HR (J. nigra ‘Hare’), SQ (J. nigra ‘Thatcher’), BJ (J. hindsii), QY (J. hindsii×J. regia ‘Paradox’), DG (J. major), PM (J. nigra ‘Pammel Park#20’) and AQ (J. nigra ‘Osage County#1’).[Method] Using Excel, SPSS Statistics and Origin 7.5, a comparative analysis was carried out on the strategy of air-dry density,absolute-dry density,air-dry shrinkage, absolute-dry shrinkage, compression strength parallel to grain, modulus of rupture, modulus of elasticity and hardness (radial surface, cross section and tangential surface). [Result] The results showed that the air-dry density, absolute-dry density, air-dry shrinkage ratio of tangential to radial, absolute-dry shrinkage ratio of tangential to radial, compression strength parallel to grain, modulus of rupture, modulus of elasticity and hardness (radial surface, cross section and tangential surface) were ranged 0.613-0.754 g·cm^-3, 0.575-0.708 g·cm^-3, 1.4-1.8, 1.5-2.4, 30.8-37.1 MPa, 86.5-123.7 MPa, 9.63-16.13 GPa, 4880-7120 N, 5720-8030 N and 4920-7270 N, respectively. The maximum value of each straits were HR (0.754 g·cm^-3), HR (0.708 g·cm^-3), BJ (1.8), BJ (2.4), AQ (37.1 MPa), AQ (123.7 MPa), AQ (16.13 GPa), HR (7120 N), HR (8030 N) and SQ (7270 N). The minimum value of each straits were BJ (0.613 g·cm^-3), BJ (0.575 g·cm^-3), PN (1.4), PN (1.5), DG (30.8 MPa), BJ (86.5 MPa), DG (9.63 GPa), Bi (4880 N), LZ (5720 N) and Bi (4920 N).[Conclusion] The results showed that there were significant difference among strains in air-dry density, absolute-dry density, absolute-dry shrinkage in tangential and the shrinkage ratio of tangential to radial, compression strength parallel to grain, modulus of rupture, modulus of elasticity and hardness. Wood physical and mechanical properties of American black walnut in Henan was better than those of Manchurian walnut and Walnut, and was similar with the American black walnut in American. All the ten strains of American black walnut could be used as furniture wood. Moreover, AQ and HR were the best in all strains.

[Objective] This paper aimed to reveal the chemical features in early-stage wood forming tissue of some main commercial wood species, and its differences among species were also analyzed. [Method] Both FTIR and XRD were employed to investigate the spectrum properties in early-stage wood forming tissue of ten commercial tree species. [Result] The results showed that the principal differences were found in finger region with the wave number from 900 cm^-1 to 2000 cm^-1 of FTIR. The peaks at 1735 cm^-1 for unconjugated CO in xylans exhibited significantly lower relative intensities in softwoods than hardwoods species. The absorption bands at 1511 cm^-1 for aromatic skeletal in lignin showed obviously in softwoods, especially in Larix gmelinii and Picea jezoensis. Both in softwoods and hardwoods, the different intensities and broad peaks at 1630-1660 cm^-1 attributed to vibration of amide compounds in protein peptides. After infrared spectroscopy treated by second derivative, conifer showed significant peaks at 1266 cm^-1 due to ring plus CO vibration in guaiacyl but not in hardwood. However, hardwood showed obviously peaks at 1245 cm^-1 which resulted from syringyl ring and C-O stretch I lignin. X-ray diffraction spectrogram showed the relative high intensities at I₀₀₂, but no obvious peaks at I_am, especially in hardwood. Therefore, it is suggested that the differences should be exist in crystal form, crystal cell or size of crystalline region between early-stage wood forming tissue and mature wood. [Conclusion] The results indicated that there were differences in lignin and hemicellulose deposition in wood formation between softwoods and hardwoods. All these would be helpful to reveal the change patterns of chemicals and structure in wood cell wall development.

Urban vegetation is an important sink for carbon cycling in urban ecosystems. This study aims to promote the understanding of carbon sequestration in urban ecosystems. The literature analysis software HistCite was used, to review current status of studies on carbon sequestration in urban ecosystems both in China and abroad. The review highlighted research methodology, capacity of carbon sequestration and influential factors, and priorities of carbon sequestration studies were identified. Study of carbon sequestration in urban vegetation started in the early 1990s and attracted increasing attention since 2009. The existing literatures focus on regional assessment and reduction in carbon emission. Ground survey and estimation based on remote sensing images were the main methods used in studying carbon sequestration in urban vegetation. Currently the ground survey mainly uses the methodology of forest ecological survey. However, due to different growing conditions and higher spatial heterogeneity in urban vegetation in comparison to natural forests, it is necessary to develop a new method for estimating carbon sequestration that is adaptive to urban ecosystems. The remote sensing method is better for large-scale analysis and is spatially explicit. Nevertheless, it also suffers from relatively low accuracy in land-cover classification in urban ecosystems. Even high spatial-resolution images are available, it is often very costly. Urban vegetation can reduce carbon concentration in the atmosphere directly via biomass accumulation or indirectly through the reduction in fossil fuel consumption. Such indirect pathways include the reduction in energy consumption of urban infrastructure, the alleviation of hot island effect, and the promotion of green transportation etc. In recent years, focus of the studies is shifting from carbon sequestration capacity assessment to the underlying mechanisms of its dynamics under both human and natural disturbance. Factors that influence carbon sequestration in urban vegetation mainly include plant growth and replacement, land cover and land use changes, human modification and management. Some clear results are:urban vegetation has a higher carbon sequestration capacity in its early growth stage; the change from forests to constructed areas in humid regions will reduce carbon sequestration; urban vegetation helps to offset the reduction in carbon sequestration in constructed areas; Garden maintenance and management increases carbon sequestration but its own carbon emission cannot be ignored. With improvement in understanding of carbon sequestration of urban vegetation, there will be more cities conducting assessments. Existing data are difficult to aggregate due to differences in methods of survey and estimation, becoming a bottleneck for the development of this research field. Using garden waste to produce biofuel may help to offset the carbon emission from garden maintenance and management. Research priorities for the next step should be set to methods for life cycle assessment and accounting for the carbon emission from human design and management.

Wood-plastic composite(WPC)belonging to bio-composites is a kind of non-toxic, recyclable and eco-friendly material. It has developed rapidly for two decades since the end of the 20th century. But now the development of WPC comes to a bottleneck. Low mechanical properties, especially poor toughness, make the application of WPC narrow, which is one of the main reasons what restrict the development of the WPC. Many researches show that adding fibers into WPC to produce multiple structural composite, is an effective way to improve the strength of WPC. In this paper, the current research status of fiber reinforced WPC is summarized. Fibers used as reinforcement for composites are divided into natural cellulose fibers, synthetic fibers, inorganic non-metallic fibers and metal fibers. The production methods and reinforcing effects of the WPCs reinforced with fiber, such as glass fiber, mineral fiber, carbon fiber, aramid fiber, polyethylene terephthalate fiber and hemp fiber et al., are reviewed. The results show that different fibers have different effects on strength or toughness of WPCs. There is a "critical value" for the addition quantity of short fibers. When the fiber content is less than the "critical value", the addition quantity and enhancement effects are positively correlated, however, contrarily negative correlated is observed when the fiber content above the "cirtical value". It is obviously that the effect of continuous glass fiber on the impact strength which increases 20 times. The natural cellulose fiber (NCF) reinforced WPCs have been used in auto parts field with high added value in Europe, though the application is not very popular. The enhanced mechanisms of fiber reinforced WPCs such as crazing mechanism of shearing band, rigid particles strengthening theory, multiple slit theory and the theory of composite mechanics, et al. are also summarized. These theories can be used to explain the mechanism of fiber reinforced WPC. And the latter two theories are most used. This article also points out that there is no one theory which can fully disclose mechanical behavior of WPC because of its complex structure tend after adding fiber. The influences of fiber addition on the mechanical properties, moisture and thermal properties of the composites are summarized. It is find that adding fiber can not only improve the mechanical strength of WPC, but also have a positive effect on reducing the moisture absorption and improving the thermal stability. Besides, some fibers can also improve the crystallinity of the matrix. The article concludes with the industry prospects and the problems of fiber-reinforced plastic composites. These issues include that improving production efficiency, developing special equipment for fiber-reinforced plastic composites, developing technology for continuous fiber-reinforced plastic composites and pioneering markets for high performance and high value-added WPC.

[Objective] In order to explore the effects of different regeneration pattern on the dynamic distribution of fine root biomass, and to examine the relationship between fine root biomass and soil properties, the fine root biomass and soil nutrient availability were investigated in primary forest, secondary forest and plantation, respectively. [Method] This study was carried out in mixed broadleaved-Korean pine(Pinus koraiensis) forest, secondary birch forest (natural regeneration after clear cutting), Korean pine plantation and Dahurian larch(Larix gmelinii) plantation (artificial planting after clear cutting) in Xiaoxing'an Mountains. Fine roots (≤2 mm in diameter) and soil samples were collected by taking soil cores successively from May to September in 2013 for each forest type. [Result] The results showed that fine root biomass in the mixed broadleaved-Korean pine forest and Korean pine plantation were significantly higher than that in secondary birch forest and Dahurian larch plantation. There were significant differences in the vertical distribution of fine root biomass in the four forest types. Fine root biomass was mainly distributed in 0-20 cm soil layer, and the highest was in the secondary birch forest (75.81%) and the lowest was in the mixed broadleaved-Korean pine forest (62.73%). There were seasonal fluctuations of fine root biomass in the four forest types. In each forest type, both fine root biomass and necromass showed two peaks. There was no significant correlation between soil temperature and fine root biomass in the four forest types, however, there was a highly significant positive correlation between soil moisture and fine root biomass in the three regenerated forest types (except the mixed broadleaved-Korean pine forest). The soil hydrolysis nitrogen content was highly significantly correlated with fine root biomass in all the four forest types. The available soil phosphate content was significantly negatively correlated with fine root biomass in the secondary birch forest. [Conclusion] Fine root biomass in the Korean pine plantation and mixed broadleaved-Korean pine forest were significantly higher than that in the secondary birth forest and Dahurian larch plantation dominated by pioneer species B. platyphylla and L. gmelinii, respectively. The vertical distribution of fine root biomass was not even, but mainly concentrated in the soil surface where nutrient availability was higher. Forests in climax stage adopted a more refined strategy of accession to resources than forests in early succession stage, thus the proportion of fine root biomass in bottom soil layers was significantly higher in the mixed broadleaved-Korean pine forest and Korean pine plantation. The seasonal dynamics of fine root biomass was consistent with phenological rhythm, and the peak of fine root biomass appeared in late spring and early autumn.

[Objective] Larix gmelinii plays a vital role in economic development and ecological environment construction in China, however it distributes in the region where summer drought intensity and drought frequency are high. Thus, it is necessary to clarify the water management strategy. [Method] A rainfall exclusion experiment including three water regime treatments (100% rainfall exclusion-100%RE, 50% rainfall exclusion-50%RE, and control-CK, i.e., ambient rainfall) was conducted in Dahurian larch plantations from May to September 2012 to monitor the water relations of trees including water potential, stomatal conductance, relative water content, and pressure-volume water parameters in a natural environment at Maoershan Forest Research Station, Northeast Forestry University. [Result] The midday water potential was lowest for the 100%RE treatment, followed by the 50%RE treatment, and the highest for the CK during the experiment period in which the decreasing precipitation directly led to a substantial reduction of soil moisture. The seasonal variation amplitude of midday water potential for 100%RE, 50%RE, and CK was 0.81, 0.68, and 0.54 MPa, respectively. The greatest difference in midday water potential between 100%RE, 50%RE and CK was 0.49, and 0.37 MPa, however the differences between predawn water potential and midday water potential for the three treatments were all similar, averaging about 0.71 MPa. The highest percentages of decrease in stomatal conductance for 100%RE and 50%RE were 84% and 79%, and the highest percentages of increase in water use efficiency (WUE) for 100%RE and 50%RE sample were 140% and 58% compared with the control. Moreover, the relative water content (RWC) of twigs for 100%RE and 50%RE was similar, and was 7% lower than that of the control. In addition, the main water parameters derived from pressure volume curves for the three treatments were similar, suggesting that the parameters were relatively stable in response to the decrease of soil water content.[Conclusion] The above results indicated that stressed L. gmelinii maintained the relatively constant RWC and water potential gradient measured as the difference between predawn and midday water potential by decreasing stomatal conductance, increasing WUE, and probably via osmotic adjustment. Regulation of water status for L. gmelinii is the near isohydric behavior along the isohydry/anisohydry continuum.

[Objective] This paper aimed at accurately assessing whether there are deviations or not and grasping the differences among tree volume tables of larch (Larix spp.) in different regions, so as to provide the basis for revising and improving the two-variable tree volume tables.[Method] Based on the newly collected volume data of 480 sample trees of larch from four regions, i.e., northeastern, northern, northwestern and southwestern regions, the current two-variable tree volume tables for different regions were examined using adaptability test method of regression equations, the differences of two-variable tree volume equations were analyzed using mixed model approach, and the two-variable tree volume equations with region-specific parameters were developed using dummy-variable model method.[Result] The validation results of 4 two-variable tree volume tables published as ministerial standards showed that the estimation errors of three tree volume tables exceeded allowable range (±3%) and the largest error reached to about 12%, indicating significantly systematic bias. From the results of difference significance test of two-variable tree volume equations for different regions, it was found that the four regions ranked by volume estimate from large to small as northeast, northwest, southwest and north; the difference of volume estimates between northeastern and northern regions was highly significant (P<0.01), that between northwestern and northern regions was significant (0.01≤ P< 0.05), that between northeastern and southwestern regions was lowly significant (0.05≤ P< 0.10), and those between any other two regions were not significant. The developed tree volume equations with region-specific parameters showed that little differences were existed among three modeling alternatives, i.e., one population only, two populations and four populations for four regions. From the comparison of two alternatives, i.e., one generalized volume equation for the whole country and four volume equations for four regions, the largest relative error of volume estimates in different regions was only about 3%.[Conclusion] Most of the two-variable tree volume tables published as ministerial standards are probably biased, it is recommended that all two-variable tree volume tables should be systematically examined, and the biased volume tables should be updated or revised. The differences of two-variable tree volume equations among different regions are not so large, and it is suggested that the population classification for developing two-variable tree volume equations for major tree species should be considered by State Forestry Administration at national level. It is necessary to develop gradually a system of forestry tables covering the whole country to promote the standardization for establishing forestry tables.

Robinia pseudoacacia ‘Beilinhuai 1’ is a new variety selected from one mutation of R. pseudoacacia K5. It grows rapidly with fewer lateral branches on the trunk, shorter and finer thorn, longger leaflet, heavier dry weight of 100 leaflets, lower contents of acid detergent fiber compared with the normal R. pseudoacacia and K5. Thus,the new variety is an excellent multi-purpose variety. The variety can be easy to be propagated and afforested.

The five cultivars were selected from the inter-sectional hybrids between herbaceous and woody species in Paeonia genus for their typical inter-sectional hybrid traits contenting novel colors, prolonged floral longevity, and vigorous growth. Among them, ‘Jing Hua Xu Ri’ has single or lotus flowers with red petals inserted by yellow or purple stripes; ‘Jing Jun Mei’ has single flowers with yellow petals and attractive red flares; ‘Jing Hua Zhao Xia’ has single and small flowers with pink petals inserted by light yellow and light purple stripes; ‘Jing Gui Mei’ has lotus formed, pink flowers; and ‘Jing Rui Huang’ whose flowers are lotus and light yellow with light red flares, has generally some sterile carpels transformed from the stamens. They can all propagated by grafting or division.