The seasonal changes in water balance components were simultaneously measured in middle-aged(22 a)and mature(58 a) Pinus tabulaeformis forests in Taihang Mountain by using "space replacing time" method. The results indicated that the total evapotranspiration(406.87-418.49 mm) and total water output (431.07-459.57 mm)did not differ substantially between two forests. However, evapotranspiration and water output components varied with forest ages, Compared with these in the middle-aged forest, the proportion of arbor canopy transpiration, arbor canopy interception, litter interception and surface runoff to precipitation in the mature forest decreased by 6.01%,2.21%,0.81%,and 0.26%, respectively, while the proportion of evapotranspiration and interception of the shrub and grass layers and the soil water outflow increased by 8.80%,3.87%,and 2.94%, respectively. Variation in stand age might be the main factor affecting relative contribution of evapotranspiration and water output components without changing their total amount. In growing season, the soil water content in the mature forest decreased slightly, whereas it increased by small amplitude in middle-aged forest.

The tree-ring stable isotope technique is an important means to reconstruct climate chronology and to determine tree responses to environmental factors. In this study, the tree-ring samples of Abies faxoniana, collected in 2010 in a sub-alpine forest of Wolong Sichuan, were used to develop the tree-ring width chronology and the stable carbon isotope was extracted based on the standard dendrochronology methods. This new approach can be used to establish the detrend series (DS) of stable carbon isotope of tree rings to eliminate effect of the ¹³C originated from atmospheric CO₂. Results showed that the stable carbon isotope series (1904—2009) varied in a range of-23.33‰—-26.31‰ with the average value of-24.91‰ and the coefficient of variation of-0.025. Correlation analysis revealed that the tree-ring DS values were significantly positively correlated to the mean monthly temperature of the last January, and the February and November of the current year (P ≤0.01), and was also correlated to the mean monthly temperature of the last November and the January of the current year (P ≤0.05). The DS values were positively correlated to the January monthly precipitation of the current year (P ≤0.05), but displayed no significant correlation with monthly relative humidity. The most sensitive variable to influence the DS values was the winter temperature. It is concluded the stable carbon isotope of tree rings would provide crucial information for dendroclimate reconstruction in the warm and humid areas, and rational explanations about responses of tree rings to climate change in the subalpine dark forest in China.

By means of fixed-point monitoring, in this paper, we investigated variation in soil moisture at apple orchards in different regions, with different growth years and different site types, as well as ordinary and dwarf apple trees were studied in Shaanxi Province by fixed spot surveillance. The results showed that soil water storage of the apple orchards in Shaanxi reduced gradually from south to north, and the soil water deficit was exacerbated. In the dry season, the degree of soil water deficit was up to 18.5%-47.5% in hilly and gully regions of Northern Shaanxi, was 7.8%-20.3% in valley and gully region of the Loess Plateau, and was only 1.2%~6.3% in Guanzhong Plain. In growth season, variation range of soil moisture content reduced with increased soil depth in the apple orchards. The change of soil moisture content mainly occurred in 0-2.2 m in hilly and gully region of Northern Shaanxi and the coefficients of variation (CV) were 12.67%-35.32%, in 0-1.8 m in valley and gully region of the Loess Plateau with CV of 11.72%-24.54%, and in 0-1.2 m in Guanzhong Plain with CV of 13.63%-20.76%. Soil water storage declined with increase of growth years in the apple orchards within a region. In hilly and gully region of Northern Shaanxi, soil moisture content was highest in sloping land, followed by platform, and then terraced field. In valley and gully region of the Loess Plateau, soil moisture content in highland was highest, followed by flat land, and then platform. Soil moisture of dwarfing orchards was higher than ordinary orchards with the same stand density, but soil water storage of dwarf orchard with higher stand density was lower than ordinary orchards with lower stand density.

Soil microbes drive carbon and nutrient cycling in forest ecosystem. Soil microbial biomass is commonly limited by environmental factors and soil carbon availability. We employed two forest-grass systems of alder (Alnus formosana) + regrass (Lolium multiflorum) (AL) and alder (Alnus formosana) + limpograss (Hemarthria compress) (AH), as well as alder + natural weed (AN) that served as control, in a returning farmland to forest land in Danling, Sichuan Province, to investigate dynamics of soil organic carbon (SOC) and soil microbial biomass carbon (SMBC) content. The results showed that soil organic carbon and soil microbial biomass carbon content in the two forest-grass compound models and the control (AN) all decreased with depth of the soil layers (0-10, 10-20, 20-30, 30-40 cm), and the decrease speed was fastest in AN, followed by AL and then AH model. The dynamic of SOC content of the three models over the all soil layers exhibited a "down-up-down" trend from spring to winter, except 0-10,10-20 cm in AH model. The SOC content was highest in summer, and lowest in autumn. However, SMBC content exhibited the opposite trend, highest in autumn and lowest in summer. There was significant difference in soil organic carbon and soil microbial biomass carbon between the two forest-grass compound models and AN (P <0.01), and the rank was in an order of AH model>AL model>AN model. The content of soil organic carbon in AH, and AL was 1.24-1.55, and 1.16-1.30 times of that in AN; and the content of soil microbial biomass carbon in AH, and AL was 1.50-2.95, and 1.23-1.80 times of that in AN.

In this study, effects of sprouting number of Quercus variabilis on the seedlings growth and biomass accumulation were investigated with the 103 stumps in Qinling Mountain. Four treatments of removing sprouts were applied on the stumps after clearcutting, i.e. no removal of sprouts serving as control, reserving 1 sprout, 3 sprouts or 5 sprouts per stump with all other sprouts removed. The results showed that the number of sprouts per stump reduced from the second year and then tent to stabilize the number in the fourth year after clearcutting during 5 years observation. Different treatments profoundly influenced sprout growth. The mean diameter, height, and crown of sprouts were decreased with the increasing of sprout number per stump. The basal diameter and height of Q. veriabilis sprouting seedlings under different treatments showed that: sunny slope>shady slope; Compared with the control, basal diameter, and height of the reserved sprouting seedlings grew more rapidly in the first 3 year. The basal diameter and height of sprouts decreased with the increasing of the reserved sprout number. For 5 years after clearcutting, the biomass of sprout various components under different treatments in two habitats was ranked as: item>branch>leaf. With the reserved sprout numbers per stump increased, the total sprout biomass increased at first and then reduced, and the 3 sprouting seedlings reserved produced the most biomass. The result indicated that sprout numbers reserved on each Q. variabilis stump had significantly influence on sprouting seedling growth and biomass accumulation. The 1 sprout per stump reserved facilitated the seedling growth, while 3 sprouts per stump reserved favored to total seedling biomass accumulation. Reservation of no more than 3 sprouts per stump would achieve the different purposes to the secondary forest cultivation.

In this paper we investigated effects of apoplastic ion dynamic changes in the tender stems of Populus wutunenses and "P.simonii×P. euphratica"×P. sp. on gas exchange parameters under salt stress. The apoplastic ions were monitored by microdialysis and atomic absorption, and the gas exchange parameters were determined with a portable photosynthesis system. The net photosynthetic rates (P_n) of the two poplar cultivars all decreased with increasing salt-treated duration. The stomatal conductance (G_n) and intercellular CO₂ concentration (C_i) of P.×wutunenses increased and then decreased, whereas its stomatal limitation (L_s) exhibited a contrary changing trend. The G_n and C_i of "P. simonii×P. euphratica "× P. sp. gradually reduced, whereas its L_s increased gradually. The results indicated that the photosynthetic inhibition of P.×wutunenses under the stress of 100 mmol·L^-1 NaCl resulted from non-stomatal limitation and stomatal limitation successively, whereas that of "P. simonii×P. euphratica "× P. sp. resulted from stomatal limitation throughout the entire experiment. P_nS of the two poplar cultivars were negatively correlated with Na⁺ concentration and Na⁺/K⁺ ratio significantly, however were positively correlated with K⁺ concentration extremely significantly. A multiple linear stepwise regression analysis was performed with P_n as the dependent variable, and Na⁺, K⁺, Ca²⁺ concentrations and Na⁺/K⁺ as the independent variables. P_n was only significantly correlated with Na⁺/K⁺ aomg those independent variables. P.×wutunenses was more salt-tolerant than "P. simonii×P. euphratica "× P. sp. under salt stress. The statistical equation showed that apoplastic ion contents in the tender stems of poplar cultivars were collinearly correlated with their photosynthesis performance under salt stress.

Twelve ericoid mycorrhiza (ERM) fungal isolates were used to inoculate 2-year-old Rhododendron annae Franch. seedlings to study effects of the inoculations on the plant growth potential, biomass and endogenous hormones contents and enzyme activity. The results showed that the inoculations with ERM significantly increased height, diameter, leaf area, mainroot length and biomass of the seedlings. The height increased by 29.47%-73.68% than that control, and diameter increased by 11.16%~70.09%. The total biomass increased by 3.86%-61.22%, of which the highest increase in shoot dry weight was 99.69%, and and the highest increase in underground part dry weight was 27.27%. The contents of indole acetic acid(IAA), gibberellin (GA₃), zeatin riboside (ZR), abscisic acid (ABA) and the activity of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) in the inoculated seedlings with ERM were significantly higher than those in non-inoculated plants, while the malondialdehyde (MDA) content was less than that of control. ERM fungi might promote the growth of R. annae seedlings through secreting hormone or stimulating the secretion of plant hormones, or coordinating several hormones. As for the comprehensive effects of the inoculations, strains TY35, TY18, TY29, TY19, TY02, and TY12 were selected as optimum ERM isolates for seedlings of R. annae.

The role of H₂O₂ in the synthesis of betulin in cells of birch (Betula platyphylla) induced by fungal elicitor was studied using suspension cell lines as the test materials. The results showed that the exogenously applied H₂O₂ decreased the cell viability and dry weight accumulation, however promoted the synthesis of betulin. Of them, the content of betulin was increased by 89.45% under treatment with 1 mmol·L^-1 H₂O₂ for 12 h, and was increased by 73.72% under treatment with 0.1 mM H₂O₂ for 24 h. The fungal elicitor increased the synthesis of H₂O₂ and betulin by 391.67% and 185.22%, respectively. H₂O₂ scavenger catalase (CAT) significantly decreased induction effects of the fungal elicitor in H₂O₂ and betulin production in the birch cells and the contents reduced by 73.10% and 35.96%. The results suggested that H₂O₂ participated in the fungal elicitor-induced synthesis of betulin in birch cells.

Caragana korshinskii is an important cultivated shrub with high ecological and forage value, and widely distributes in Northwest China. C. korshinskii has a strong tolerance to drought, cold, heat, saline and poor soil. In order to study its resistance mechanisms to drought and explore for drought response related genes, a suppression subtractive hybridization (SSH) library of C. korshinskii under drought stress was constructed. Totally 1 286 ESTs from the SSH library were obtained and the average length was 475 bp. As many as 645 Unigenes were identified through the EST sequence assembly. Many drought-related genes were annotated by Blasting, such as the genes encoding dehydration related LEA and DHN proteins as well as transcription factors including MYB, bZIP, WRKY, NAC, and bHLH families. A candidate gene encoding a member of WRKY transcription factor family was cloned by rapid amplification of cDNA ends technique, and was named as CkWRKY 1 (GenBank accession No. JX987095). The protein deduced from the cDNA was composed from 330 amino acids with a conserved region "WRKYGQK". Real-time-quantitative PCR analysis showed that drought stress enhanced CkWRKY 1 expression at the transcriptional level, indicating that CkWRKY 1 might be involved in the drought resistance mechanisms of C. korshinskii at molecular level.

In this study, leaf area, branch length and angle, vessel diameter, vessel density and the tissue proportion of the first order branch were investigated in upper crown, middle crown and lower crown of 7 Betula platyphylla sample trees from 8 different orientations. The results showed that leaf areas were smallest in the northwest of upper crown and largest in the south of lower crown, and the number of branches was least in the east of lower crown and most in the north of middle crown. The branch lengthes and branch angles were shortest and least in the northwest of upper crown, and the branch length was longest in the southeast and the branch angle was biggest in the north of lower crown. Vessel diameters and the tissue proportion were maximal in the west of middle crown and minimal in the south of upper crown. The vessel density was maximal in the northwest of upper crown and minimal in the south of lower crown. These results indicated that there were spatial differences in the distribution of leaves, branches and their vessel characteristics among the orientations of different crown layers. In addition, the relationships between leaves, branches and their vessel characteristics of the crown and microenvironment were discussed.

Based on data of tree biomass for natural white birch (Betula platyphylla) in northeast China forest area, two methods (controlling jointly from level to level and controlling directly under total biomass) were used to establish the mono-element and dual-element compatible tree biomass model of natural white birch. And using nonlinear measurement error simultaneous equation estimated the parameters in the model, at the same time, the weighted regression was used to eliminate the heteroscedasticity. The results showed that R² of mono-element and dual-element compatible model in this paper was 0.800-0.988, and the fit efficiency(EF)was 0.80-0.97. Besides, the precision of these models reached beyond 80%. On the other hand, the precision of foliage and branch model was relatively lower, and it was more than 69%. Among the compatible models established, the effect of total tree and stem was better than root, foliage and branch. On the whole, the compatible models established by two methods had the precision that we could receive and they could be used to predict the biomass of natural white birch with good precision. But the mono-element and dual-element compatible tree biomass model based on controlling directly under total biomass was better than the way that using controlling jointly from level to level under total biomass. To be concluded, it was advised to use the compatible model that based on controlling directly under total biomass.

Forest succession direction was an important work for natural forest management. This paper presented a new index which named natural compose index and this parameter could be used to express the difference between forest succession and the progressive succession. After making a comparison between reference trees and neighbouring trees on advantage of growth and succession level, the advantage of trees in different succession level and natural compose index could be gotten. Castanopsis sclerophylla mixed stand in Guihua Forest Farm in Hubei has been taken as an example. The new index was used to calculate and adjust in mixed stand. The mean natural compose index of this stand was 0.76, and the succession trend of this stand was progressive succession, natural compose index of 4 sample plots were respectively 0.65, 0.83, 0.79, 0.76.Combined with the analysis of different tree species, we could know that the mean natural compose index of spatial structure units whose reference tree were Castanopsis sclerophylla, Cunninghamia lanceolata, Pinus massoniana were high, this one showed that the succession trend of these spatial structure units were progressive succession, and only small parts was regressive succession; the mean natural compose index of spatial structure units whose reference tree were Liquidambar formosana, Quercus chenii were low, although the succession trend of these spatial structure units were progressive succession, more spatial structure units' succession trend were regressive succession. These spatial structure units should be timely structural adjustment, and made the forest succession direction closer to progressive succession.

In this study, the sample data was based on 432 samples of 9 trees from dahurian larch(Larix gmelinii)plantations located in Qitaihe Forest Bureau in Heilongjiang Province. The stepwise regression techniques were used to develop wood density model: WD=β₁+β₂RN+β₃RN²+β₄h. Then, the developed model was fitted using single level and multilevel linear mixed-effects modeling approach based on LME procedure of S-PLUS software. The mixed effects models showed better model fitting results than basic model whatever considering single level and multilevel linear mixed effects. Moreover, the mixed effects model considering height effects and both effects showed more precision than that considering individual tree effects. Model test indicated that mixed effects models not only showed the mean trends of wood density, but also showed the variations among groups.

Individual tree information is significant to the study of stand growth, stand structure, stand management and stand visualization. The Huangfengqiao State-Owned Forest Farm in Hunan Province was selected as a test area. Six typical and pure Chinese fir plantations of the same age were chose as the research objects. The corresponding relationship between the diameter class and the Voronoi polygon area was studied. The following works were carried out by taking simulated plots for example and setting the tree number, the stand arithmetic mean DBH and the plot size. By researching the tree distribution pattern, the generation algorithms of lattices were established. The diameter class distribution was estimated by using the Weibull distribution model. According to the law between the Voronoi polygon area and the diameter class, the diameter class was allocated. The tree height and crown were estimated based on the models of the tree-measuring factors. The visual model of individual tree information estimation based on stand characteristics was established by using GDI+, MOGRE and Arcgis Engine10 development technology that could analyze the Voronoi polygon in the plot. The results showed that there was a positive correlation between the arithmetic mean of Voronoi polygon area and the diameter class, that the generation algorithms of tree distribution patterns were efficient and applicable, that because the allocation of diameter class referred to the impact of space environment, it was closed to the law of tree growth, and that the visual simulation technique could directly express all the processes and the results and enhance the maneuverability. This method that can solve the difficult problem of individual tree information estimation based on stand characteristics can provide the underlying data for forest research and the technical reference for forest visual simulation.

The soil fauna, as an important part of the wetland ecosystem, has attracted more and more attention. They play a vital role in the material circulation and wetland restoration processes. In August 2010, we investigated soil animals in different vegetation covers (A: Rumex acetosa lakeshore, B: Tree and shrub lakeshore, C: Crop lakeshore, D: Natural reed lakeshore) at Lake Taihu lakeshore wetland with Tullgren and Baermann's methods. A total 537 soil animal individuals were extracted and classified into four phyla, and 59 taxonomic groups. R. acetosa lakeshore (A) had the lowest density of soil animals (4 017 ind·m^-2), while tree and shrub lakeshore (B) had the highest density of soil animals (14 496 ind·m^-2). There were differences in soil animal community space similarity over the four vegetation cover types, suggesting that vegetation cover types had an impact on soil animal community species composition, richness of communities and the number of dominant groups. The horizontal distribution pattern of the soil animals in the number of individuals was B > C> D > A. The canonical correspondence analysis (CCA) was used to analyze the correlations between the distribution of soil animal communities in the different caver types and the soil moisture content, pH, conductivity, soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP), or soil temperature. The result showed that different soil animals had differential responses to different environmental factors, and various soil factors had to different degrees impact on the distribution of soil fauna. Among them, total phosphorous (TP) had a relatively strong impact on the Carabidae larvae, Ceratopogonidae larvae and Liocranidae, while electric conductance (Cond) had strong impact on Neanuridae. SOM had a greater impact on Isotomidae, pH had a greater impact on Onychiuridae, and soil temperature had a greater impact on Enchytraeidae. This study would provide scientific reference for wetland restoration.

Two species in genus Mycena, M. corynephora and M. metata, were collected in Shandong Province in a survey of macrofungi resources, and found to be new to China. The two species all have warts in their cheilocystidia. In this paper we describe in detail their appearance characteristics, microscopic characteristics and the difference between them and related species, and present illustrations of the two species. The specimens are deposited in the Mycology Herbarium of Ludong University (HMLD).

Six extracts were obtained from the fermentation liquid of Trichoderma harzianum strain T28 by using different extract methods and organic solvents with different polarity. Inhibiting activities of the extracts on Phytophthora infestans were tested. The extracts with high inhibiting activities were further analyzed with GC-MS. The results indicated that the extracts obtained with step-by-step extraction method and ethyl acetate extract had the optimum inhibiting effect on mycelial growth, sporangium germination and sporangium released zoospores of P. infestans, with the inhibition rates of 67.06 percent, 71.71 percent and 76.25 percent, respectively. Ethyl acetate-extracted ingredients in the sequential extraction and the direct extraction process were analyzed with GC-MS, and 10 and 15 components were identified, respectively; the same components in the two extraction methods included 2,5-di-tert-butylphenol, di-tert-butyl phthalate, diisobutyl phthalate, eighteen methyl carbonate, dibutyl phthalatel and mono-2-ethylhexyl Phthalate. These components might be the active chemical ingredients which inhibited P. infestans.

To select effective triazole formulations against wood rot fungi, the inhibition zone test was conducted in this paper. The decay and termite resistant performance of formulations comprising triazoles was evaluated by laboratory sand block test and filed stake test. The inhibition zone test showed that cyproconazole (CY), tebuconazole (TEB) and propiconazole (PPZ) were effective against brown rot fungi (GT) and white rot fungi (TV). The result of laboratory sand block test showed that the rational retention was 200 g·m^-3 and 1.0 kg·m^-3 respectively for PT (PPZ:TEB=1:1) and CuPT (Cu:PPZ:TEB=50:1:1) at the circumstance of exterior above ground (C3 use class). The result of field test showed that the rational retention should be more than 3.6 kg·m^-3 for CuCY (Cu:CY=98.6:1.4) at the circumstance of exterior ground contact (C4.1 use class) whereas the termite is very severe.

This paper was carried out to study the characteristics of white birch (Betula platyphylla) disk drying checks(such as the position, MC of check formation, morphology)under stepwise decreasing relative humidity and constant temperature of 40 and 60℃ drying conditions. On that basis, the effects of geometrical characteristics of tree disk, namely, growth eccentricity(GE), roundness deviation(RD)and cross-sectional area(S)on drying checks were investigated. The results showed that under the same drying condition, the early formation of checks within disks with different position, diameter and roundness deviation(RD)had a significant difference. Under 40℃ and 60℃ drying conditions, the early formation of checks' average MC value was 43.9% and 45.6%, respectively. The occurrence of checks was earlier under 60℃ than 40℃ drying condition. Also, the early formation of checks' position was on the border between heartwood and sapwood. Under 60℃ drying condition, the position of checks was slightly expansion to inter with heart checks emerging. Although check total length(CTL)and check average width(CAW)under 60℃ were greater than 40℃ drying condition, there was no significant difference under two drying conditions. The number of V-checks was under 60℃ more than 40℃ drying condition, obviously. The roundness deviation(RD)and cross-sectional area (S)were the main factors that effected check total length and V-check. The disks with larger cross-sectional area(S)and more irregular shape were prone to triggering drying checks during the drying process. Therefore, it was necessary that tree disks were sorted by geometrical characteristics prior to drying.

The grafting method is widely adopted for developing lignin-based polymer materials with high properties. Aimed at studying various initiators (Fenton, K₂S₂O₈, H₂O₂-CaCl₂) effects on calcium lignosulfonate from eucalyptus (HLS-Ca) in graft copolymerization, HLS-Ca was treated by the above initiators, respectively. Changes in the functional composition of HLS-Ca were investigated by using Difference UV, FTIR, UV spectroscopy and intrinsic viscosity ([η]) methods. The results show that the changes in the structure and reactivity of HLS-Ca were observed due to some certain reactions between it and initiators. Under our experimental conditions, the benzene ring stable against the oxidation of Fenton and K₂S₂O₈ initiators; the content of phenolic hydroxyl (Ph-OH) group decreases under the incubation of Fenton and K₂S₂O₈ initiators though it's not oxidized to the structure like quinone; the content of aryl-ether,[η] and viscosity-average molecular weight (Wη) increase. Under the treatment of H₂O₂-CaCl₂ initiator, the content of Ph-OH group decreases dramatically and it could be transformed to carbonyl structure. The destruction of benzene ring results in the decrease in the [η] and Wη for HLS-Ca.

In this paper, we investigated the effects of 4 plant growth regulators (PGRs), including Benzyladenine, Ethrel, Methyl Viologen and Jasmonic acid, on growth, heartwood formation and essential oil composition of young Santalum album through a stem injection method. The results showed that there were no significant differences in heightand DBH growth, but all the above PGRs promoted formation of fragrant heartwood in young sandals, and the heartwood was the same appearance and texture with naturally produced heartwood. There were extremely significant differences (P <0.01) in the amount of induced heartwood among different PGRs treatments, and the rank of the treatment efficiency was in the following order: Methyl Viologen=Ethrel>Benzyladenine=CK>Jasmonic acid. There were significant and extremely significant differences in both relative content (P <0.05) and absolute content (P <0.01) of essential oil distilled from these heartwood among different treatments, of which Benzyladenine treatment yielded the highest relative content and absolute content, and the average content was 5.55% and was 8.77% respectively. The components of essential oil induced by different treatments were nearly the same. However, contents of α-santalol (P <0.05) and β-santalol (P <0.05) were statistically different, ethrel treatment had the highest α-santalol content, with 46.05%, while benzyladenine treatment had the highest β-santalol content, with 23.35%. All treatments, except for jasmonic acid, produced oil which quality met with the ISO standard for S. album oil, indicating that the process of the heartwood formation can be regulated by phytohormones, of which benzyladenine may be one of the most useful phytohormones in controlling heartwood formation of sandal.

Economic transition is a major strategy by which resource-exhausted cities can achieve a sustainable development. This study established an indicator system for efficiently estimating economic transition of Yichun, a forestry resource-based city, through improving the two-stage relative evaluation. This paper comprehensively utilized the SPSS 17.0 statistical analysis software, Super Decision calculation software and Matlab 7.0 analysis software to analyze the essential dataset, and scientifically estimated the efficiency of economic transition of Yichun. This study analyzed the motivation of the economic transition efficiency at every stage, highlighted the efficacious substitution of traditional technique factors with the ecological technique factors, and determined the necessity and feasibility of enforcement of economic transition, so as to provide theoretical base for the successful accomplishing economic transition of the forestry resource-based city, Yichun, and thus achieving its socio-economic harmony, stable and orderly development.

The seedlings of 16 elite Masson pine (Pinus massoniana) families, with stable high-yield, including family 35, 38, 76, 78, 79, 80, 88, 89, 90, 114, 115, 116, 117, 119, 16, 147, and 151, were used to explore the effects of precipitation acidity on their acid tolerance. The physiological parameters (biomass, relative plasma membrane permeability, chlorophyll) of the families cultivated in root-boxes outdoor were measured under treatments by spraying simulated acid rain at different pH values (2.5, 3.5, 4.5 and 5.6). The results showed that the biomass and chlorophyll content decreased with the increase of rain acidity, but the ratios of chlorophyll a/b increased with the increase of rain acidity. In addition, with the rain acidity increased, the relative plasma membrane permeability of the pine seedlings increased, suggesting that the injury of cell membrane was enhanced. These parameters varied with different P. massoniana families. Meanwhile, when rain pH decreased from 5.6 to 4.5, these parameters were slightly decline, but a significant decline was observed from pH 3.5 to 2.5, indicating that these pine families had relatively high productivity under mild acid environment at pH 4.5 to 5.6, and suggesting the tree species, Masson pine, would be suitable for being planted in mild acid soils.

Construction of a mathematic model for forecasting viviparous propagule yield of Bruguiera gymnorrhiza is important for mangrove forestations and mangrove management. In this study, viviparous propagules of B. gymnorrhiza were used as the research object in Mangrove Nation Natural Reserve at Gaoqiao, Zhanjiang city, Guangdong province. The indexes of different layers were investigated, and then the multivariate analysis in regressive and path analysis were conducted to construct a mathematic model for forecasting viviparous propagule yield of B. gymnorrhiza. The result showed that: B. gymnorrhiza seed yield was very significantly correlated with the diameters of basal stem and crown. It also had significantly positive correlation with the diameter and crotch angle of lateral branches in first class, leaf length, or leaf-shaped index, suggesting the seed yield had close relationships with phenotypic characteristics. Thus, we could regulate the yield by changing the phenotypic characteristics. With multiple stepwise regression analysis we constructed effective regression equation: Y =-148.131+127.471 X₄-11.113 X₅+2.048 X₇, which can be used for forecasting and controlling B. gymnorrhiza viviparous propagule yield. The results of path analysis showed that the factors determining the seed yield were X₄ > X₇ > X₅. Thus, increasing the crown is the best way to increase the seed yield for individual B. gymnorrhiza.

In this paper we investigated the population fruiting characteristics and fecundity of Toona ciliata var. pubescens, an endangered plant species, in Jiulianshan National Nature Reserve in Jiangxi province. The results showed that there existed on-and off-year phenomenon in fruiting with 1 year interval. The fruit setting rate was generally low in a natural pollination. Seed yields in a given fruiting year were affected by environmental conditions and climate. During the on-year of 2010, the seed yield was about 700 g per plant, with an annual average of fruit-setting rate, number of cones per flowering branch, number of seeds per cone, and seed-setting rate for 8.91%, 22.91, 29.55, and 12.01%, respectively.The net reproductive rate, intrinsic increase rate, finite increase rate and generation span of T. ciliata var. pubescens population was 0.038 4,-0.078, 0.854 6, and 41.74 a, respectively. The fruiting and sexual fecundity characteristics showed that the T. ciliata var. pubescens populations were subjected to reproductive constraints of the less fruit-setting with many flowers in a natural pollination and a lower environmental fit together, thus the natural population would tend to a slow negative growth.

In order to select special nut-processed cultivars, we measured and analyzed a number of economic indexes of 43 cultivars and varieties of 5-6 years old Ping'ou hybrid hazelnuts (Corylus heterophylla × C. avellana) planted in the same orchard with identical management at Anqiu county, Shandong province. The processing traits of the nuts and kernels were measured and the traits were graded according to the forestry industry criteria and China Fruit's Monograph. The results showed that nut weight varied from 1.45 g to 3.30 g, nut shape index varied from 0.67 to 1.08, kernel weight varied from 0.76 g to 1.44 g, shell thickness varied from 0.90 mm to 1.76 mm and kernel weight percentage varied from 35.06% to 56.00%. The processing traits, such as nut size, plumpness of the kernel, thickness of the shell and kernel percentage of most candidates reached to relative higher grades of the industry standards, indicating the high potential selectivity in the population. There were significant differences in the economic traits among the candidate cultivars and varieties and the variation coefficients (CV) were 5.30%-70.31%. There were to different degrees relationships between paired traits, which should be considered for the cultivar selection. However, there were small amount of round nut types in the population, which was a limiting factor in the selection of nut-processed cultivars. Based on this study, the main traits and criteria for selecting special nut-processed cultivars included in turn, nut weight ≥ 2.00 g, kernel weight percentage ≥ 40%, kernel plumpness 0.80-0.90, kernel weight ≥ 0.80 g, round nut (nut shape index 0.90-1.00). Four cultivars and varieties i. e. ‘Liaozhen No. 2', ‘Ping'ou 30', ‘Ping'ou 90' and ‘Ping'ou 28' were selected as the special nut-processed cultivars.

Bamboo plays an important role as a kind of vegetation with contribution to soil and water conservation,Mechanics property of roots play a crucial role in mechanics of soil-reinforcement. In order to find the tension properties of the bamboo roots underground, the tensile experiment for the roots of three kinds of monopodial bamboo, Phyllostachys edulis, Pleioblastus amarus and Phyllostachys sulphurea, was implemented in the field. The experiment employed our own portable experimental equipment for testing tensile characteristics of root. Tensile force and strain rate of roots with different diameters was tested for these three kinds of bamboo. Then, their tensile strength and elastic modulus were obtained through calculation. The experimental results show that the tensile force of monopodial bamboo root increases regularly by the power function regulaas the increase of the root diameter, and the tensile strength of root reduces along with the increase of root diameter by the power function. The average anti-tension of these three bamboo roots is Phyllostachys edulis(71.96 N), Pleioblastus amarus(62.05 N)and Phyllostachys sulphurea(63.13 N), and their average tensile strength is Phyllostachys edulis(16.46 MPa),Pleioblastus amarus(26.07 MPa)and Phyllostachys sulphurea(19.35 MPa), The ultimate strain has limitation from 13% to 24%. The average elastic modulus is Phyllostachys edulis(67.1 MPa),Pleioblastus amarus(182.03 MPa)and Phyllostachys sulphurea(168.01 MPa). Compared to the three kinds of bamboo, Pleioblastus amarus root has the best comprehensive tensile properties. Next are Phyllostachys sulphurea,and Phyllostachys edulis root respectively. Compared with the common afforestation tree Pinus tabulaeformis, Betula platyphylla,Larix gmelinii, monopodial bamboo roots have better tensile mechanical properties.

P.deltoides ‘Nanyang’, male clone and intraspecific hybrid of Populus deltoides hybid, was selected from the progeny of Populus deltoides CL.55/65'× P. deltoides CL. ‘2KEN8’ by the way of artificial control cross pollination. Average DBH, height and volum of six-years ‘Nan’were 20.70 cm, 15.0 m and 0.183 4 m³, which were 22.3% and 14.7% more than ‘Zhonglin 46’ and I-69. The elite variety has the fine characteristic of up straight trunk, narrow crown, fast-growing, high resistance to Anoplophora glaberipennis, moderate resistance to Apriona germari and waterlogging tolerance.