[Objective] The study was intended to understand characteristics of species diversity in forest dynamics plot (FDP) which located in subtropical evergreen and deciduous broad-leaved mixed forest community in Mulinzi National Nature Reserve, Hubei Province, and to analyze patterns of temporal and spatial changes of species diversity of subtropical evergreen and deciduous broad-leaved mixed forest, and further to provide a basis for exploring maintenance of species diversity, community dynamics, environmental heterogeneity and regulation of ecosystem functions.[Method] The 15 hm² (300 m×500 m) forest dynamics plot was established according to the protocol of the CTFS for field plots establishment in 2014 in Mulinzi National Nature Reserve, Hubei Province. All woody plants with diameter at breast height (DBH)≥1 cm were mapped and identified, and the species diversity were analyzed.[Result] In the 15 hm² FDP there were 84 189 individuals belonging to 228 species, 112 genera and 61 families. There were 11863 individuals belonging to 130 species, 71 genera and 44 families when 10 cm was the minimum measured diameter at DBH, and there were 1 721 individuals when 30 cm is minimum measured diameter, belonging to 67 species, 40 genera and 29 families. Species richness rapidly increased with the expansion of sampling area in the 0-3 hm² when 1 cm and 10 cm were minimum measured diameters, and over 80% of the total species were presented in 6 hm² size. Species richness also quickly increased with sampling area in the range of 0-0.2 hm² when 30 cm was the minimum measured diameter, and there was also over 80% of the total species were at 8 hm². The number of individuals was over 1000 from 18 species accounting for 7.89% of the total number of species, but the number of individuals of these species accounted for 70.63% of the total numbers in plot. These parameters would provide a scientific basis in determining the minimum sampling area of subtropical evergreen and deciduous broad-leaved mixed forest community. Cyclobalanopsis myrsinifolia and C. multinervis dominated the forest canopy, and the importance values were ranked the second and third. Eurya japonica occupied most of the understory, and showed the highest abundance. There was a high proportion of rare species in the plot, a total of 116 species, accounting for 50.88% of the total number of species, but the number of individual trees of rare species accounted for only 0.14% of the total number of individuals. Fagaceae and Theaceae were the important families in evergreen broad-leaved forest in Mulinzi. There were total 18 880 woody plants of 137 sprouting species, belonging to 76 genera and 42 families in the plot, accounting for 22.4%, 60.1%,62.8% and 65.6% of the total number of individuals, species, genera and families, respectively. All these woody plants, there was 1 073 individuals of 64 species, belonging to 43 genera and 26 families when 10 cm was the minimum measured diameter, and 46 individuals of 17 species, belonging to 15 genera and 9 families when 30 cm was the minimum measured diameter.[Conclusion] There were abundant species in subtropical evergreen and deciduous broad-leaved mixed forests in Mulinzi National Nature Reserve, mainly composed of Fagaceae and Theaceae. There were high proportions of rare species and sprouting species. The large number of sprouting species was probably closely related to human disturbance and special habitat conditions before establishment of the nature reserve.

[Objective] The objective of this study was to provide a scientific basis for healthy management and rational utilization of secondary forests of Betula platyphylla. [Methods] A typical debarked B. platyphylla stand was selected in the north region of the Yanshan Mountains. Spatial characteristics and relationships between wind-breakage and debarking were determined using spatial gradient analysis, point pattern analysis and a binary Logistic model. [Results] Debarking intensity reduced gradually from the outer to the inner portions of the stand,and was higher in sparse patches, flat slopes or gully bottoms than dense patches, and slopes. Debarked stems were clustered and were negatively associated with non-debarked stems at scales of 36-50 m, and there was no association at smaller spatial scales. Average heights of lower and upper borders of debarking area were 0.52 and 1.72 m respectively, and debarking occurred on the south-western or southern side of the stem. Debarked B. platyphylla usually suffered from wind-breaking 4-9 years after debarking and usually broke at lower or upper debarking point on the stem. Most debarked stems fell towards north-east with most falling azimuths ranging from 0° to 135°. There was a competing relation between recovery growth of the stem wound and decay of exposed wood. The greater the percentage of exposed stem circumference of debarked trees, the more vulnerable the debarked stem to wind breakage. A binary Logistic model could be used to depict the probability of wind-breakage of debarked trees, using percentage of exposed stem circumference as variable. [Conclusions] Debarking in B. platyphylla was characterized by multi-scale spatial characteristics and was mostly impacted by tree location, stand density, and topography. Debarked trees were clustered and were negatively associated with non-debarked stems at larger scales. Debarking tended to be more serious in the area with more debarked trees. The more the trees were damaged, the more likely they were broken by wind. Management should emphasize reducing the amount of debarked trees in more vulnerable areas of stands in the early spring. Bark should be collected after tree cutting and be utilized in appropriate products.

[Objective] Remote sensing technique provides a highly effective means for extracting tree species (group) spatial distribution information. The objective of this paper is to develop a method for estimating the provincial spatial distribution information of forest tree species (group) composition using multi-sources data. Thus it could indicate the spatial distribution information of the main tree species (group) and provide a new method for extracting vegetation information in large area. [Method] The experiments were carried out over the test site of the whole Jilin Province. The time series MODIS NDVI product of 250 m pixel size and 8 days cloudy free composite and the permanent forest plot data collected by the national forest inventory (NFI) were used as the key data sources. The weather observation data and topography data were also integrated into the data sources. We developed a gradient nearest neighbor (GNN) based approach for estimating provincial forest tree species (group) composition distribution information. Firstly, the method of canonical correspondence analysis (CCA) was implemented to extract effective composited features from the original dataset. Secondly, the k-nearest neighbors (k-NN) method was applied on the extracted feature space to estimate forest tree species (group) composition number using one two-layer stratification scheme. As the value of k needs to be determined, the changing trend of k-NN estimation accuracy with the k values was analyzed. Finally, the estimation accuracy for each tree species (group) of the developed method was validated using the forest plot data of 9 counties collected by the forest resources inventory in second level and the forest plot data collected by the NFI as reference. [Result] 7 tree species (group) composition numbers including Quercus mongolica,Betula platyphylla,Tilia amurensis,Ulmus davidiana,Populus,Juglans mandshurica and Larix olgensis were extracted and the corresponding distribution maps were produced. The results showed a good consistency with the fixed plots in field. Taking county as statistic unit, the following quantitative technical targets have been achieved:the coefficient of determination (R²) was 0.83, and the RMSE was 0.34. Specifically, the accuracy has been further validated by dividing the whole coverage of Jilin Province into grids of 20 km×20 km,30 km×30 km,40 km×40 km and 50 km×50 km, taking the forest plot data collected by the NFI as reference and the grid as statistic unit. Better results could be achieved at the scale of 40 km×40 km and 50 km×50 km. The RMSE of Ulmus davidiana composition number was 0.35 and the RMSE of Quercus mongolica composition number was 0.65. The optimal k-value could be determined for the phenomenon that the RMSE firstly reduced and then tended steady with the rising k-value. In addition, the estimation accuracy of the two-layer stratification estimation method was higher than that of the direct estimation method. The results showed that:the average RMSE of estimating tree species (group) composition using two-layer stratification estimation method was 0.1 less than that using direct estimation method.[Conclusion] The proposed method for estimating the provincial spatial distribution information of forest tree species (group) composition using multi-sources data has proved to be an effective method to estimate forest parameters. Based on this method, the distribution map of forest tree species (group) composition numbers was successfully produced with high accuracy. The results indicated that the value of k needs to be optimized in order to obtain a better result, which varies depending on the experimental area and the selected data. In addition, the estimation accuracy could be improved effectively using two-layer stratification estimation method.

[Objective] This paper established the nonlinear mixed effects model for height-diameter relationship in multi-storied and multi-species mixed forests. The purpose of this study was to provide some references for the further study on growth rule in mixed forests. [Method] A total of 87 temporary plots were used in Larix principis-rupprechtii and Betula platyphylla mixed forest of Saihanba National Forest Park, Hebei Province, China. Plot size was 20 m × 30 m. A total of 4953 individuals of Larix principis-rupprechtii and 3 608 individuals of Betula platyphylla were investigated. 13 typical models were selected to fit height-diameter relationship. The best-fit model was chose as the basis for building mixed-effects models. Both fixed-and random-effects parameters expressed in terms of high species strengths and stand basal area were considered to establish height-diameter relationships. Furthermore, dummy variables were added to the mixed-effects models in order to solve intra-plot variability resulting from species difference. The goodness-of-fit criteria used were the coefficient of determination (R²), the absolute error of estimate (Bias) and the root mean square error (RMSE). [Result] 1) Among the 13 pieces of height-diameter candidate models, model 13 (M13) provided the most accurate prediction of height with the highest R²(0.9157), the lowest Bias (1.200 6) and RMSE (0.129 1). 2) For Larix principis-rupprechtii and Betula platyphylla, mixed effects models were established based on M13, respectively. Both models had the best fits with the fit statistics values (R²=0.926 4; AIC=319.7; Bias=0.084 1; RMSE=1.070 8) for Larix principis-rupprechtii and values (R²=0.918 7; AIC=297.6; Bias=0.070 5; RMSE=1.1022) for Betula platyphylla. 3) To further evaluate mixed-effects models for two species, trees from the validation data were divided into different DBH classes with every 2 cm interval. The average values of height prediction bias (observed-predicted) were small for both species. The above results indicated that mixed-effects models including species dummy variable provided in a better fit to the data and improved prediction accuracy. [Conclusion] The mixed-effects models with dummy variables solved the negative effects of species differences between plots and within plot on height-diameter relationships in mixed forests. It was proved able to provide better model fitting, more applicability and more precise estimations than the basic generalized model.

[Objective] Previous researches on the cooling and humidifying effects of urban green space mainly base on the large-scale and obscure the influence of plant community structure and tree species. However, this study based on the fine-scale investigated the daily dynamics in air temperature and relative humidity and the accurate cooling and humidifying effects of the five landscape plant communities during a calm sunny summer day, aiming to provide a reference for their landscape application as well as provide the theoretical basis for planning and construction of the urban green space system. [Method] In the Beijing Olympic Forest Park, five landscape plant communities with different canopy structure characteristics, including Populus tomentosa community, Ulmus pumila community, Salix matsudana community, Koelreuteria paniculata community, and Ginkgo biloba community, were selected as the research object. The open turfgrass lawn served as control open space site. The air temperature, relative humidity, wind speed, and canopy structure characteristics were measured in the field on calm sunny summer days. The collected data were processed and quantitatively analysed in every minute through the EXCEL2010 and SPSS19.0 software, to detect the detailed diurnal variation in the air temperature and relative humidity of the every studied community and to compare the cooling and humidifying effects among the five communities. [Result] The results showed that diurnal variation in the air temperature and relative humidity of the five plant communities displayed a single peak in the 24 h of a day and the periods in which a state of high temperature and low humidity was maintained were different among the communities. The period of high temperature and low humidity appeared at 11:00 to 16:00 in P. tomentosa community, 12:00-17:00 in G. biloba community, and 11:00 to 17:00 in S. matsudana community which was relatively longer than other communities. However, there was no obvious high temperature and low humidity state in U. pumila and K. paniculata communities. Additionally, all the five plant communities had the significant cooling and humidifying effects during 08:00 to 18:00 when they lowered the air temperature by 3.0 to 4.3℃ with an average of 3.7℃. Meanwhile, compared with the control open space site, they increased the relative humidity by an average of 11.3% and ranged from 10.2% to 12.8%. However, these two effects in the studied communities were not significantly different from the control during 18:00 to 08:00 except in the U. pumila community. [Conclusion] On the basis of measured data per minute, there was a unimodal diurnal variation in these two microclimate indices in the five frequently-used communities and the diurnal variation in air temperature was more stable than that in relative humidity. Moreover, these plant communities had different influence on the air temperature and relative humidity within the internal environment likely because of the difference in canopy structure characteristics. These cooling and humidifying effects tended to be significant during the daytime while they were not significant during the night. Therefore, this study might form a theoretical reference for people to pleasantly employ the urban green space with the five tree species. Furthermore, other frequently-used tree species would be investigated on this issue, to provide a reference for the scientific planting design to build a urban green space with the pleasing temperature and humidity, as well as to promote the comfort degree for outdoor activities.

[Objective] The growth of Rhododendron moulmainense is closely related with light intensity and soil drainage, therefore, selection of appropriate light intensity and soil drainage conditions is of great significance for introduction and cultivation of R. moulmainense. [Method] Different shadings (0%,30%,50%,80%) and different soil drainage measures (High ridge and Flat ridge) were applied in the article. The branch increments and some physiological indexes in leaves of R. moulmainense were measured, and the correlations between branch increment and the physiological indexes were analyzed. [Result] The results showed that under 50% shading and high ridge treatments, the branch increment, and chlorophyll content and RWC in leaves of R. moulmainense were highest. The relative conductivity, contents of MDA, soluble sugar and soluble protein, and SOD activities in the leaves were lower or the lowest. Under 0% shading and flat ridge treatments, the branch increment, and chlorophyll content and RWC in leaves of R. moulmainense were lowest, whereas the relative conductivity, contents of MDA, soluble sugar and soluble protein, and SOD activities were highest. In general, with increasing shading and soil drainage, the branch increment, and chlorophyll content and RWC in leaves had a trend of gradual increase, while the other measured indexes all appeared a trend of gradual decrease. Correlation analysis showed that there was an extremely significant negative correlation between the branch increment with SOD activity, relative conductivity and MDA content, indicating that the branch increment of R. moulmainense was closely related to the changes of these three indexes in stress environment. Thus, the adaptation degree of R. moulmainense to habitat can be determined by means of above three indexes. [Conclution] According to these experiment results, it is speculated that R. moulmainense would be suitable for growing in the habitat with 50% shading and good drainage soil.

[Objective] VHAc is an important subunit of V-ATPase which responds to salt and heavy metal stresses. In previous studies, we have identified that overexpression of Tamarix hispida ThVHAc1 in yeast can improve its tolerance to NaCl and CdCl₂. In present study, we further explore the mechanism of ThVHAc1 in response to NaCl and CdCl₂ by comparing the expression activities of different lengths of ThVHAc1 promoters under stresses.[Method] According to the distribution of Dof cis-element in the ThVHAc1 promoter, ThVHAc1 promoter was divided into three segments including 205 bp (-1- -205), 504 bp (-1- -504) and 781 bp (-1- -781). The CaMV35S promoter in pCAMBIA1301 was replaced by these three different lengths of ThVHAc1 promoter (205, 504 and 781 bp), respectively. And these recombined constructs were transformed into Arabidopsis thaliana using Agrobacterium-mediated method. The T₄ lines of the transgenic plants at 4 weeks old were treated with 100 mmol·L^-1 NaCl, 150 μmol·L^-1 CdCl₂ and H₂O (non stress treatment as control) respectively for 30 min to compare the GUS staining and activities of transgenic plants. [Result] Under normal growing conditions, the root, stem and leaf of CaMV35S seedling showed GUS staining. The GUS staining was also observed in different tissues of the three transgenic lines expressing promoter segments, and there were some differences among root, stem and leaf tissues. However, the total GUS activities of these three promoter segment lines were 781> 504> 205. Under NaCl stress, the GUS staining and activity of CaMV35S line were not obviously different from that growing in normal condition (no stress), however, the GUS staining and activity of three promoter segments transgenic lines were significantly decreased, the GUS activity of the 781 line was 2.73-fold of the 205 line and 2.07-fold of the 504 line. Meanwhile, the tissue expression of transgenic lines of the three promoter segments were changed, for instance, old leaves of the 504 line showed increased GUS activity while the young leaves were decreased, and root showed no evident changes. Under CdCl₂ stress, all transgenic lines showed patterns of GUS staining and activities similar to NaCl stress, the GUS activities of 205, 504, and 781 were 52.4%, 57.9%, 80.9% of those under no stress, respectively. The post-stress tissue expression were also changed for CdCl₂ stress, the GUS staining of 205 line were darker in old leaves and lighter in young leaves, the GUS staining of 504 line was uniform among different tissues, the GUS staining in most leaves of the line 781 were lighter. However, the GUS activity of the line 781 was still the highest, 2.67 and 2.07 folds of the line 205 and the line 504 respectively.[Conclusion] The driving activity of ThVHAc1 promoter was positively correlated with its fragment length. The GUS staining and activity of the three promoter segments were different in the roots, stems and leaves of the transgenic seedlings, indicating a certain extent of tissue specificity of different promoter segments. NaCl and CdCl₂ stresses generated certain influence on the driving activity of ThVHAc1 promoters, the post-stress GUS activities of the three promoter segments in the transgenic lines were significantly decreased, but the impact was weaker on long length promoter than on short ones. The number of Dof motif was successively reduced in turn in the three promoter segments of 781, 504, 205, indicating Dof motif may play some roles in regulating NaCl and CdCl₂ stresses. Meanwhile, the tissue expression of ThVHAc1 promoter was more or less affected by NaCl and CdCl₂ stresses.

[Objective] Poor natural regeneration and over-exploitation have resulted in the continual decline of natural forests and trees of Toona ciliata. In depth studies of genetic diversity and structure of T. ciliata of different provenances are particularly important for conservation, utilization of genetic resources, and the development of future breeding programs for the species.[Method] Sequence-related amplified polymorphism (SRAP) markers were used to investigate genetic diversity of 29 provenances from China and one provenance from Australia of T. ciliata to define the level of genetic diversity and the relationships among different provenances. Samples from China were collected from natural stands. Each provenance was represented by 30 sample trees with a distance of at least 50 m among the sample trees. The Australian provenance was taken from the resources collection nursery of the South China Agricultural University. The POPGENE1.32 software was used for genetic diversity parameters calculation. The NTSYS-pc2.1 software was used for cluster analysis based on the matrix of Nei's genetic distances and the degree of genetic relatedness among provenances was assessed by principal coordinates analysis (PCoA) and MANTEL analysis with GenAIEx 6.5. STRUCTRUE 2.3 was used to analysis the genetic structure. [Result] A total of 505 polymorphic bands were amplified by 24 pairs of primers. The average value of polymorphism information content (PIC) was 0.41. The average value of Nei's gene diversity index (H) was 0.3770. Shannon's information index (I) within provenances ranged from 0.1575 to 0.467 5, the average value was 0.556 9 among provenances. The AMOVA indicated that 79.24% of the total variation was among provenances and 20.76% was within provenances, revealing that provenance selection is important for the breeding of T. ciliata. In STRUCTURE analysis, 30 provenances were divided into two groups. Group Ⅰ included the provenances from central and eastern China. The provenances of southwest and south China and the provenance of Australia formed Group Ⅱ. Isolation-by-distance (IBD) patterns were revealed in the provenances of China by Mantel test. The unweighted pair group method of arithmetic averages (UPGMA) cluster showed that the 30 provenances could be classified into four clusters. Cluster Ⅰ consisted of the 14 provenances from Central China and East China. Cluster Ⅱ consisted of only Lechang provenance. Cluster Ⅲ was composed of provenances mainly from South China and Southwest China, but the two provenances from Guangdong province were not classified into the same cluster. GroupⅣ was composed of provenances from Guangdong (YF) and the provenance of Australia. The result was consistent with biplot of PCoA analysis. [Conclusion] Habitat fragmentation of the natural distribution has led to spatial isolation among populations, low rate of gene exchange and limited gene flow, resulting in geographic variation among provenances. The UPGMA cluster analysis and PCoA analysis demonstrated a clear variation pattern consistent with the geographical trend of T. ciliata. Studies of artificial reproduction should be reinforced while carrying out protection of the original habitat, and collect all current genetic resources and expand the range of collection as far as possible.

[Objective] The aim of this study was to probe into the influences of ecological restoration on the diversity of carabid beetles (Coleoptera:Carabidae) and selection of microhabitat by these beetles in different habitats, which can beneficial to reveal the process of ecological restoration and provide scientific basis for biodiversity conservation in the hill and gully area of Loess Plateau, Ningxia Hui Autonomous Region.[Method] An investigation of carabid beetles was carried out using pitfall traps in six habitats, namely, shrub and grass mixed forest land(SG), tree and shrub mixed forest land(TS), ecological fuel-wood forest land(EF), ecological economic forestl and(EE), natural enclosed grassland(EG) and level terraced field(TF) from June to August in 2012 and 2013. Microhabitat selection of carabid beetles was analyzed by Logistic regression model, and further the key environmental factors with influencing microhabitat selection by carabid beetles were explored.[Result] The results showed that we trapped 3 236 individuals of 16 species, belonging to 9 genera, among which Amara gebleri, Carabus brandti and Dolichus halensis were the most dominant species and accounted for 40.64%, 24.13% and 20.02% of abundance in the study area, respectively. The number of individuals of carabid beetles and Shannon-Wiener diversity index all showed significant differences among habitats (df=5, P=0.011; df=5, P=0.021), and species richness was relatively higher in shrub and grass mixed forest than other ones, but the difference was not significant among habitats (df=5, P=0.062). There was a marked difference in Chao-1 richness estimation curves in each habitat. Species richness estimation approached an asymptote, and indicting that the almost all species were captured in shrub and grass mixed forest and ecological fuel-wood forest, and the most species were captured in natural enclosed grassland and level terraced field. In contrast, species richness at tree and shrub mixed forest and ecological economic forest showed no indication of approaching an asymptote, and there was considerale variation in the estimates of species richness. The occurrence probabilities of these dominant species were significantly different among habitats. Multiple logistic regression analyses displayed that biomass of herbs and soil water content were the critical habitat factors for microhabitat selection by Amara gebleri. Cover of canopy, cover of shrubs, biomass of herbs and soil water content were the importantly environmental factors for microhabitat selection by Carabus brandti. Cover of shrubs, cover of herbs, depth of leaf litter, biomass of herbs and soil water content were key factors for microhabitat selection by Dolichus halensis. [Conclusion] There was a marked difference in microhabitat selection of carabid beetles in this study, which could be an important bioindicator for assessment of ecological restoration.With the knowledge of habitats preference of these species, we can guild how to further strengthen the ecological restoration and habitat protection. This study is of practical importance for biodiversity conservation and ecological construction in the hill and gully area of Loess Plateau, Ningxia Hui Autonomous Region.

[Objective] Pinus armandii distributes widely in the Erlang Mountain and is one of the dominant species in the community. The Erlang Mountain Forest Farm is located in Sichuan Province and it contains rich microbial resources. This article was intended to study the fungal diversity and analyze the relationship between fungal structure and their functions at the beginning of the P. armandii litter decomposition period. [Method] The grinding method was used in this paper to isolate fungi on the P. armandii litter from the altitude of 2 750, 2 650, 2 510, and 2 460 m. The isolates were further indentified according to the morphology combined with PCR amplification and sequencing using the universal primers based on the ITS sequence of fungi. In addition, the Rhizosphaera was for the first time isolated from P. armandii, and the relevant research on the fungi is still insufficient. There remains controversy on the fungal role as a pathogen or weak parasitic fungus in foreign reports. The fungus was reported to cause disease on P. sylvestris var. mongolica in China in 2013. In this study, 12 strains of Rhizosphaera were isolated from the four elevations. To study the saprophytic performance, three strains of Rhizosphaera sp. with different morphological features, namely R. sp.1, R. sp.2 and R. sp.3, and one strain of Lophodermium erlangshanense were selected for decomposition test in vitro, in which the P. armandii litter is the sole substrate. [Result] The isolation results showed that 23 fungi taxa were obtained. The imperfecti and ascomycetes were the major components that occupy 15 taxa and 5 taxa, respectively. All of the fungi belonged to 15 genera. Mucor, Trichoderma, Rhizosphaera, Penicillium and Talaromyces were isolated from the plots over the four different elevations, and were the abundant species. The filamentous fungi, such as Trichoderma, and Penicillium, which had the quantitative superiority and diversity, undoubtedly would play an important role in the process of litter decomposition. However, basidiomycete fungi, without abundant amount and species, might not participate in the decomposition at the early stage. The basidiomycete fungi originated from the environment may participate in the further lignin decomposition at the late stage. Through the determination of cellulose enzyme produced by the fungi, the activities of endoglucanase and β-glucosidase reach the maximum at the 13th day. The activities of Cellobiohydrolase reach the maximum at the 17th day. In general, there was no significant difference in the enzyme activities as well as the mass loss among the four strains. Those results indicated that Rhizosphaera sp. and L. erlangshanense could decompose the cellulose components, and there was a synergistic effect from the different cellulase enzymes (endoglucanase, cellobiohydrolase, β-glucosidase). The mass loss decomposed by L. erlangshanense was 15.74%, while the loss caused by Rhizosphaera sp. ranged from 12.00% to 13.40%. According to the previous researches, L. erlangshanense was usually found in the litter and rarely in alive needles, suggesting that it may not cause the needle disease. [Conclusion] The results indicated that filamentous fungi, such as Trichoderma, and Penicillium, played an important role at the beginning of the litter decomposition period. They were both the dominant species in the four different altitudes. Rhizosphaera sp. and L. erlangshanense were weak saprotrophic fungi in the P. armandii litter. However, it needs to be further verified that whether the capacity of cellulose decomposing enzyme is related to their pathogenicity.

[Objective] In this study, two methods were applied to establish fire prediction model for Tahe, Daxing'an Mountains. Our objective is to identify the applicability of random forest algorithm to local forest fire prediction according to prediction accuracy comparison. This study would provide some technical support for local forest fire management. [Method] The fire data collected in Tahe, Daxing'an Mountains between 1974 and 2008 were used in a case study to identify the relationship between fire occurrence and meteorological factors by using logistic regression (LR) model and random forest (RF) algorithm, respectively. In order to reduce the influence of sample distribution on the model fitting, the original dataset was randomly divided into training (60%) and validation (40%) samples. The procedure was repeated five times applying a sampling with replacement method, thus obtaining five random sub-samples (sample groups) of the data, each with a training and validation dataset. The predictors that had been proved to be significant at ɑ=0.05 in at least three of five intermediate models were included in the final models. Besides, in the present study a "cross validation" test was to identify the accuracy of the two models. [Result] The results of model parameter estimation indicated that daily minimum relative humidity, fine fuel moisture content (FFMC) and drought code (DC) were identified as important predictors in both Logistic and Random Forest model. The result of model fitting revealed that the prediction accuracy of LR model in five intermediate models were 8% and 10% lower than that of RF,respectively, for the training and variation samples. However, the prediction accuracy of RF on the complete dataset was 15% higher than that of LR. In the Cross Validation test, the prediction accuracy of RF was 85.0%, higher than that of LR (76.2%) and the result agreed with that of five sample groups. [Conclusion] Our results revealed that the RF model was superior to LR model on the fire prediction in the study area, thus the RF model can be used in the fire prediction and provide important information for the local fire management and plan.

[Objective] Urea-formaldehyde resin adhesive was the most widely used adhesive in the world. When the molar ratio of urea/formaldehyde reduced, the corresponding formaldehyde-emission decreased greatly, but at the same time the strength of plywood also declined dramatically. Therefore, many researches showed that the adhesives modified by melamine can effectively reduce formaldehyde-emission, and the wet strength of adhesives with low molar ratio was improved. However, low-formaldehyde-emission urea-formaldehyde resin modified by melamine resulted in extending the gel time, which cannot be solved by adding curing agent. [Method] Aiming at shortening the curing time and enhance production efficiency, different activators in urea-formaldehyde were studied by analyzing solid content, curing time, free formaldehyde content and hydroxymethyl content. DSC was applied on the dynamic analysis of curing reaction. DEA was used to investigate the resin curing process. moreover, FTIR analysis was also carried out to compare functional groups after adding different additives to select an appropriate catalyst for shorting the resin curing time and reducing formaldehyde-emission.[Result] Adding the ammonium chloride, ammonium boric acid, ammonium phosphate and ammonium sulfate respectively during addition polymerization, the curing rate of low molar ratio urea-formaldehyde resin was all improved significantly. Four kinds of activators had played an significant role in reducing the curing reaction activation energy, especially for the ammonium boric acid and ammonium sulfate. According to the results of DEA, four kinds of activators obviously accelerated resin curing, particularly for the ammonium boric acid and ammonium sulfate. After adding four kinds of activators, the strength of hot-pressing plywood almost remain unchanged and formaldehyde-emission reduced.[Conclusion] when the amount of (NH₄)₂SO₄ was 0.3% of the total weight during addition stage, the activation energy of the cure reaction was greatly decreased, and the curing time was also considerably reduced. Moreover, the formaldehyde emission of the plywood can meet the requirement of F^**** for JIS.

[Objective] The concept and system structure of compound forest products are researched. The path, motivation and strategy of the evolution of value chain are also discussed. The result can provide theoretical basis and practice models for integrating the compound value system, optimizing configuration of the regional resources and upgrading the value chain.[Method] Based on the analysis method of system, using the theory of value chain, product positioning and industrial agglomeration, the structure of the compound forest products dimension and the evolution path of value chain are discussed. A three-level spatial evolution strategy model which integrates production of forestry resources, forestry ecological and forestry cultural was put forward. [Result] 1) Compound forest product has multi-dimensional function and compound value. The product forms are provided for different target market and consumer groups. The optimization of resource allocation can be obtained through the market segmentation and market positioning. Compound forest product value chain can be subdivided into three levels, which are the corporation value chain, the region value chain and industry value chain.2)The main evolution mechanism includes endogenous driver of market, exogenous driver of government and coupled driver among regions. The driver of market is resulting from the interaction of enterprise competitiveness and market logic. The driver of government emphasizes dominant function during the evolvement of the forestry industrial value chain. The driver of coupled emphasizes the complementary cooperation among regions. Then it discusses the segment of evolution mechanism, which evolving from production chain to development chain or brand chain on corporate level, from value network to value system on regional level, and from native product to derivative product on industrial level.3)The core strategy of dynamic mechanism includes cultivating ability of leading company, creating a regional cluster brand and collaborating domestic value chain of compound forest product. The core enterprise should strengthen R&D of knowledge innovation diffusion and product branding, which can derive the scale effect and brand effect of forestry industry cluster. The domestic value chain should be constructed and be embedded into global value chain. [Conclusion] From the micro aspect, a generic technology research and development base of the compound forest products should be built by the local government. The government should coordinate complementary enterprises of the value chain and provide core enterprise with technical and marketing support. From the middle aspect, the value chain should be integrated, the regional forest products brand should be built and the tourism industry compound forest product should be developed through the appropriate industrial policy. From the macro aspect, the government should balance the economic and ecological benefits of compound forest products and establish regional complementary advantage of the compound system of forest products.

[Objective] This study presents a review of the development history and management profiles of forest parks, in order to provide suggestions for the healthy and sustainable development of forest parks in China.[Method] A literature review and a qualitative analysis were conducted to explore basic information and management dynamics of the sector of forest parks in China. In addition, a quantitative analysis was carried out to describe spatial patterns of forest park development. Specifically, from the time dimension, development stages of forest parks were clarified and the characteristics of each stage were summarized, and an impact analysis was conducted on changes in socio-cultural factors and development guidelines at each stage. From the spatial dimension, a statistical analysis was conducted on tourism revenue, number of tourists, and social employment of forest parks in a total of 31 provinces in China.[Result] 1) China's forest parks have gone through four stages:the starting and experiment stage (1980-1990), rapid development stage (1991-2000), standard development stage (2001-2010), and upgrading stage (2011 till now). A three-level of national, provincial and municipal (county) forest parks management system was used in China, and main types of forest parks are usually classified by resource types, size of tourism area and forest ownerships. 2) The guidelines of sector management of forest parks have also evolved. At the beginning of reforming and opening up, forest parks was considered as one of the business projects of the state-owned forest farms. Then, the implementation of natural forest protection program since 1998 facilitated the function transformation of forest parks. During the "eleventh-five year" (2006-2010) period, national forest parks were defined as "national cultural and natural heritage" and "zone of national ban of development". 3) A preliminary sector management system for forest parks in China has been established, industrial development has been scaling up, and a new stage of public tourism has come, strengthening the protection of natural resources, promoting the development of forest tourism and dissemination of eco-culture, and driving the growth of regional economy. 4) Bottleneck problems of development were identified, including low legal status limiting effective management and protection of forest parks, irrational quantitative structure of forest parks due to imbalance among different places and slow development of forest parks at municipal(county) level, poor professional background of staffs, lack of tourism products such as recreational and healthy activities in forest parks leading to low efficiency of multiple uses of forest parks, and poor international reputation and social recognition of forest parks. [Conclusions] In summary, the development trend of forest parks from 1980 to 2014 was good. However, it varied among different provinces. The "five-combination" principles are suitable for development of forest parks in the new stage, including combination of the functions of forest parks with diversified socioeconomic needs, combination of forest park development with national development strategy, combination of strict protection with rational utilization of forest resources, combination of eco-forestry with people's livelihood, combination of valuable international experience in protected areas with national realistic conditions. Future work should be focused on establishing legal system and standards, resource inventory, investment channels, personnel training, international exchanges.

[Objective] Water is the main factor limiting vegetation restoration and sustainable development of agriculture and forestry in Loess Tableland. The main purpose of this study was to investigate the evapotranspiration of an apple orchard in the growth cycle, in order to provide a theoretical basis for scientific management of regional apple orchards and the improvement of potential productivity. [Method] Water balance method was used to calculate the evapotranspiration of a young apple orchard in the Loess Tableland during growing season (from Mid-April to Mid-October) in 2012-2014. Rainfall was recorded in real time by automatic weather station in real time and calibrated in combination with manual observation to ensure the continuity of rainfall data. The water storage capacity of soil in a profile of 6 m was measured using a neutron probe (CNC503B) on the 15^th and 30^th day of each month, for the 0-100 cm soil layer, the readings were recorded by every 10 cm, and for the 100-600 cm soil layer, the readings were recorded by every 20 cm. Then the soil water storage was calibrated with soil-auger-drilling method. [Result] The evapotranspiration of the apple orchard showed an obvious bimodal curve, with first peak in the second half of July or the first half of August, and the second peak in the first half of September; The evapotranspiration accounted for 103%, 104% and 103% of the total rainfall during the growing seasons in 2012-2014, respectively. In addition, the evapotranspiration of the young apple orchard was 12.1 mm greater than rainfall in 2012, 18.2 mm greater in 2013, but 1.2 mm lower in 2014. The variation coefficient of evapotranspiration within a growth cycle was about 1.0. [Conclusion] The loess tableland is a typical rain-fed agricultural area, where the water for evapotranspiration mainly comes from natural rainfall. Thus, the amount of rainfall could directly affect the quality and quantity of the production of apple orchard. In dry (2012) and relatively dry (2013) years, as the evapotranspiration was greater than the rainfall, the water supply from rainfall could not meet the water consumption by apple orchard, resulting in deficit of soil water content. However, in a normal year (2014) with average precipitation the water consumption of young apple orchard can be met. The soil water and evapotranspiration of apple orchard had a rapid hydrological response to rainfall in the loess tableland, and rain water in the apple orchard can be rapidly transformed into evaporation and vegetation transpiration.

[Objective] The responses model of leaf stomatal conductance to environmental factors of Populus pruinosa in different periods constructed would be very helpful to elucidate stomatal regulation behavior of P. pruinosa, and to further simulate the dynamics of leaf photosynthesis and to develop a new water-carbon coupling cycle model in an extreme arid terrestrial ecosystem. P. pruinosa has been declining in recent years because of the increasingly worsening ecological environment, mainly caused by increased human water consumption. Up to now, the adjustment mechanisms of its stomatal conductance (G_s) are not clear. Our study is to elucidate current understanding of the mechanism that underlay the responses of stomatal conductance to variable environmental factors, and thereby to build up a model that expresses the relationship between stomatal conductance and environmental factors. This study would help us to further understand the photo-physiological characteristics of P. pruinosa and provide valuable information for protection of this vulnerable species. [Method] P. pruinosa, a constructive species of desert riparian forests in an extreme arid region in northwest China, was used as experimental material in this study. The leaf gas exchange parameters and environmental factors were measured with Li-6400 portable photosynthesis system during June to September in 2012 and 2013. The dynamic characteristics and the relationship between stomatal conductance and environmental factors were analyzed based on field observation data. Further, Jarvis and Leuning-Ball models were used to simulate the dynamic process of leaf stomatal conductance, and applicability of the two models in extreme arid region was compared. [Result] The diurnal courses of stomatal conductance of P. pruinosa were a single peak curve in growth season, there were obviously differences in peak values, time and amplitude in every months. Especially, peak time appeared the earliest and largest amplitude in September, and minimum amplitude of peak value in June. The leaf stomatal conductance was sensitive to photosynthesis active radiation, vapor pressure deficit and air temperature. The leaf stomatal conductance increased with photosynthesis active radiation, atmospheric CO₂ concentration and air humidity, and decreased with increase of the vapor pressure deficit and air temperature. Statistical analysis showed that photosynthesis active radiation, vapor pressure deficit and air temperature significantly affected stomatal conductance of whole day and forenoon, while the stomatal conductance in afternoon was affected obviously by atmospheric CO₂ concentration and air humidity. Stomatal conductance of P. pruinosa in different periods was regulated by the different environmental factors. The fitted models of stomatal conductance of P. pruinosa in different periods were simulated and constructed with two representative stomatal conductance models, Jarvis model could explain on average 69.1%, 62.2%, and 63.3% of variation and Leuning-Ball model could explain on average 53.5%, 30.6%, and 44.5% of variation in the observed stomatal conductance at whole day, forenoon and afternoon, respectively. The sensitivity and fitting effect of Jarvis model was better than that of Leunning-Ball model at different periods. The fitting effect of Leunning-Ball model in afternoon was better than that in forenoon, indicating that the environmental factors that affected stomatal conductance were different in different periods. The validations of Leuning-Ball linear and Jarvis non-linear models based on field data of leaf stomatal conductance indicated that Jarvis model was better estimation of stomatal conductance than Leuning-Ball model, and Jarvis model could improve the simulation effect of stomatal conductance. [Conclusion] The environmental factors of different periods affecting stomatal conductance of P. pruinosa were obviously different in growth seasons. The sensitivity and fitting effect of Jarvis non-linear stomatal conductance models were better than that of Leunning-Ball linear model at different periods, it had better applicability in the extremely arid-desert region. The relationship among leaf G_s and environmental factors in extremely arid Tarim basin could be expressed as:G_s=PAR(0.001T_air²+ 0.013 T_air -0.090)/((260.443+PAR)(-0.219+VPD)).

[Objective] Effects of exogenous nitric oxide(NO) on the active oxygen metabolism system of walnut seedlings under low temperature stress were studied, in order to investigate the possible mechanism of exogenous NO on the cold resistance of walnut.This study aimed at developing a new method for improving the resistance of fruit trees by applying exogenous NO and providing a theoretical basis for the wide application of NO on walnut in the future. [Method] The effects of sodium nitroprusside (SNP with 200 μmol·L^-1), a NO donor, on the active oxygen metabolism of walnut varieties ‘Xiangling’ and ‘Luguo No. 12’,seedlings with different cold resistance were studied in a artificial climate chamber. The seedling were subjected to low temperature treatments and the leaves were sprayed with SNP. [Result] 1) Under normal growth conditions, the effects of spraying SNP on the membrane permeability, chlorophyll content, production rate of superoxide anion radical(O₂^·-), H₂O₂, MDA and Pro content, and SOD and CAT activity in walnut leaves were not obvious. POD, DHAR, APX and GR activity, AsA and GSH content, GSH/GSSG and AsA/DHA ratio were significantly increased, while DHA and GSH content were reduced. The variation ranges of the two walnut varieties were different.2) Under low temperature stress, SNP treatment significantly increased the activity of POD, CAT, SOD, APX and GR, increased the content of chlorophyll, Pro, AsA, DHA, GSH and GSSG, and decreased the accumulation of MDA and H₂O₂, production rate of superoxide anion radical(O₂^·-) and relative permeability of plasma membrane. The variation ranges of the two walnut varieties were different. [Conclusion] Under low temperature stress, exogenous NO treatment could maintain the stability of AsA-GSH circulation system, decrease the accumulation of MDA and H₂O₂, production rate of superoxide anion radical(O₂^·-) and protect the stability of cell membrane structure by promoting antioxidant enzyme activity and antioxidant content, and there by reduce the damage of the active oxygen to the walnut leaf and enhance the cold resistance.

[Objective] In this study, the seasonal variation of carbon and nitrogen of microbial biomass in the Korean pine (Pinus koraiensis) mixed forests at different altitudes was investigated. This study would provide a scientific basis for comprehending the role of soil microbial communities in carbon and nitrogen cycles. [Method] In this study,we set 5 sites along the altitude gradient of Changbai Mountain, starting from the highest distribution altitude of Korean pine and down in one hundred meters altitude intervals. At the same altitude, 3 sample plots were set, and each of sample plot was 20 m×20 m in size. A total of 10 sampling points in a size of 15 cm × 15 cm were randomly set up in an S type at each plot. We collected the samples in the plots on May 21, July 19, August 23, September 20 of 2013, respectively. We analyzed the dynamic variation and different mechanism of the soil microbial biomass carbon (SMBC) and microbial biomass nitrogen (SMBN) in growing season. [Result] The SMBC, SMBN and the SMBC/SMBN had the same variation trend, that is, increased at first and then decreased with the increased altitude. The SMBC, SMBN and the SMBC/SMBN all reached to their maximum at 900 m (1287.18 mg kg^-1; 224.29 mg kg^-1; 9.29). There were significant differences in the SMBC and SMBN among the elevations (P <0.01). The microbial biomass carbon and nitrogen decreased with soil depth. The microbial biomass carbon in 0-5 cm layers of the soil was 1.15, 1.55, 1.29, 2.58, and 1.32 times higher than those in the 5-10 cm layers at the 5 elevations, respectively. The microbial biomass nitrogen was 1.50, 1.23, 1.45, 2.64, and 1.09 times higher than those in the 5-10 cm layers, respectively. In the growing season (from May to September), the SMBC and SMBN in the 0-5 cm soil layers decreased at first, then increased and decreased again. The shape of the curve is inverted "N". However, the SMBC and SMBN first increased and then decreased and presented a unimodal shape of curve in the 5-10 cm soil layer. The seasonal variation of microbial biomass carbon-nitrogen ratio among different altitudes and different soil layers were different. The microbial biomass carbon-nitrogen ratio was between 5 and 20 during the measuring periods except May. The results showed that fungi were more dominant than bacteria in microbial communities in the forests and the capability of soil humification was relative high. In August and September, the microbial biomass carbon-nitrogen ratios were highest, indicating that the capacity of carbon sequestration of soil was strongest. The content of soil available N, soil organic carbon, available P, available K and pH, and soil moisture was obviously different among the 5 elevations. Generally, all indexes increased gradually from 700 m to 900 m and reached to the maximum, and then decreased with the increased elevation. Soil microbial biomass carbon had extremely significant positive correlations with soil organic carbon, soil moisture, available N, available P and available K at different altitudes (P<0.01), and had significant positive correlation with pH at different altitudes (P<0.05). Soil microbial biomass nitrogen had extremely significant positive correlations with pH at different altitudes (P<0.01), and had significant positive correlations with soil organic carbon, soil moisture, soil available N, available P and available K at different altitudes (P<0.05). [Conclusion] The elevation gradient, soil depth and seasonal variation could impact on soil microbial biomass carbon and nitrogen content significantly. The physical and chemical properties of soil, and the difference of forest types were major factors which led to the changes of soil microbial biomass.

[Objective] The situation of land desertification in Zoige County of southwest China is severe. In order to provide scientific basis for prevention and control of futher desertification in this area, it is necessary to explore the evolution trend of land desertification in Zoige County. [Method] The process of evolution dynamics of land desertification was studied with the transfer matrix of biostatistics based on the data of four land desertification monitoring data from 1994, 1999, 2004, and 2009 in Zoige County. [Result] Desertification expansion was at a rate of 11.08% per year in Zoige County during the period from 1994 to 2009, as a result,the sand area in 2009 was 4.5 times higher than that in 1994. The average annual rate of the expansion of desertification in diverse degrees of desertification was in a regular sequence of 24.49%, 12.03%, 7.80% and 6.68% for extremely severe desertification, mild desertification, severe desertification and moderate desertification land, respectively. On the whole, the degree of arenaceous desertification in sandy land was still in the initial stage for the mild sand land accounting for 75.69% of the total desertification area, suggesting that it was the favorable period for the management of desertification. After 15 years of desertification evolution, the structure of different degree of arenaceous desertification had been changed with a trend of decreasing ratio of the moderate and severe desertification land and an increasing one of the mild and very severe desertification land in terms of desertification area ratio. The proportion of desertification degree remained stable,and that was 61.53%, 68.77% and 83.06% for the period from 1994 to 1999, 1999 to 2004 and 2004 to 2009, respectively. This proportion suggested the desertification degree was in a gradually stabilized trend in time series. The sandy land area in mitigating desertification degree was 2.23 times of the land area proportion in deterioration of desertification during the period from 2004 to 2009. The trend of sandy desertification was in the direction of mitigation. The land desertification evolution, had both gradual change and jumping process at the 5 years' scale. Due to the presence of jumping process, non-desertified land is not necessarily the safest and would evolve into the severe desertified land under certain conditions. In contrast, the severe desertification can jump into a non-desertified land under the control of human resources. In recent decades desertification evolutionary trend had been improved under the background of combat desertification. [Conclusion] Nevertheless, the land desertification in Zoige County is still quite harsh and there will still a long and arduous approach to take in the sand control task for the future.

The variety, ‘Zhengnonghongyu’, was bred by crossbreeding method with elite butterfly orchid flowering individuals as the parent in 2003 in zhengzhou institute of agricultural and forest sciences, and then selected from the offspring in a regional test in Henan, Shaanxi, and Hebei province. ‘Zhengnonghongyu’ has a compact plant type, and is easily cultured and induced to flowering. The flower diameter is 10-11 cm, the main branch bears about 10 flowers on average, and the flowers have flamboyance color, arrabgement tidiness inflorescence, and longer shelf-life.