Objective: Three different vegetation types of water source forests (arbor forest, shrub forest and grassland) in the Quanfuzhuang small watershed were in vestigated by a quantitative analysis of the soil water transportion, the source of water and the proportion of recharge to shallow groundwater of 0~100 cm soil layer to reveal the influence of three vegetation types on soil water migration. The result of this study provides a scientific basis for quantitativel analysis of water cycle process of the forest-terrace complex ecosystem and sustainable development of Hani Terrace irrigation area. Method: We examined the hydrogen and oxygen stable isotope characteristics of different water bodies under the three regetation types from April to December 2015, and the variation characteristics of δ¹⁸O value of soil water with soil depth using hydrogen and oxygen stable isotope technique on different dates(July 24, July 29, and August 3, 2015) in three vegetation types, analyzed the relationship of δ¹⁸O values between soil water and the potential water sources (precipitation and shallow underground water, etc.), and further determined the source of soil water in the three vegetation types. The contribution rate of precipitation and groundwater to soil water, surface water and soil water to groundwater were calculated according to binary linear mixed model. Result: The mean values of hydrogen and oxygen stable isotopes in the five water bodies decreased in an orderly way, with shallow groundwater being observed to have the greatest amount, followed by surface water, then soil water of arboreal lands, then soil water of shrubland, then soil water of grassland, finally Precipitation. The coefficient of variation of precipitation was the largest, and the coefficient of variation of surface water and shallow groundwater was smaller. Soil water in grassland was mainly recharged by precipitation, accounting for 67.02%. Soil water in arboreal lands and shrubland was mainly recharged by the rising of deep soil water, accounting for 59.65% and 50.18% respectively. Under the condition of short-burst rainstorm, the water transportation rate of the three forestlands in the early and late stages of monitoring were different. And the main transport ation ranges of soil water in arboreal lands and shrubland were 0-70 cm, while the main transport ranges of soil water in grassland was 0-50 cm. The vertical transportation of soil water was the main form of shallow groundwater recharge. The shallow groundwater recharge ratio by soil water of grassland was 55.91%, and it was significantly higher than that of arboreal lands and shrubland. Conclusion: The vegetation type had certain influence on the characteristic of soil water cycling in the study area, forestland had a strong utilization of deep soil water, and the grassland was more conducive to precipitation infiltration and shallow groundwater recharge.

Objective: This study was designed to characterize the variation in soil phosphorus forms and their contents in differently aged Chinese fir plantations, and analyze the correlations among various phosphorus forms, in order to provide a basis for improving the availability of soil phosphorus in Chinese fir plantations and promoting the sustainable development of Chinese fir plantations. Method: Seven Chinese fir plantations at different ages (3, 6, 12, 18, 25, 32 and 49 years) were selected from the Shanxia Forest Farm in Fenyi County, Jiangxi Province, China. Total soil phosphorus and available phosphorus were detected by molybdenum antimony scandium colorimetric method. The contents of soil aluminum-bound P (Al-P), high-iron-bound P (Fe-P), occluded P (O-P) and calcium-bound P (Ca-P) were detected by a grading method, and the correlations among various phosphorus forms were analyzed, to reveal the dynamic changes of soil phosphorus at different forest ages. Result: The soil inorganic phosphorus contents of differently aged Chinese fir plantations accounted for 55.37%~74.22% of the total phosphorus content, and the amount of inorganic phosphorus fractions was in an order: O-P> Fe-P> Ca-P> Al-P; The content of total phosphorus, available phosphorus, Al-P and O-P in soil showed a trend of first decreasing followed by increasing with age, and the minimum appeared at 12-year-old or 18-year-old, the Fe-P content displayed a gradual increased but not significantly, the Ca-P content displayed an increase first followed by a decrease. The dynamic changes of soil inorganic phosphorus with forest age indicate that the Chinese fir plantation is in the rapid growth stage during the middle forest age and absorbs a large amount of soil nutrients, prompting the activation of O-P and the release of Al-P and Fe-P under the action of root exudates, but due to the different rates of release and absorption, the content of different phosphorus forms varies. From 18-year-old to 49-year-old, the Ca-P content decreased significantly, indicating that starting from the near-mature forest, the Chinese fir plantations increased the Ca-P absorption rate and slowed down the absorption rate of other phosphorus forms, resulting in an increase of the content. The correlation analysis of various phosphorus proved that soil available phosphorus was positively correlated with Al-P, Fe-P, and O-P content (P>0.05), and O-P was positively correlated with Al-P and Fe-P content (P>0.05). Conclusion: The changes of content of different phosphorus forms in the soils of Chinese fir plantations at different ages show certain patterns. The inorganic phosphorus is the main component of the total phosphorus. And correlation analysis shows that different phosphorus forms can be transformed into each other.

Objective: Increasing forest carbon sequestration has become an important measure to deal with climate change. However, the management of plantation in China is still based on timber income, ignoring the ecological benefits of forests for carbon sequestration. To coordinate the contradiction between carbon sequestration and timber production, this paper aims to explore the optimal rotation period of Larix olgensis plantation by taking into account both carbon sink and wood production, so as to provide a theoretical basis for the multi-objective management of L. olgensis plantation in this area. Method: This study was conducted in 35 plots of Larix olgensis plantation in the experimental forest farm of Northeast Forestry University in Maoershan, Heilongjiang Province. Based on Faustmann-Hartman model, an optimal rotation period determination model of compound management of L. olgensis plantation for both carbon sequestration and timber production was constructed, in comprehensively considering the arbor layer biomass carbon pool, DOM carbon pool, forest product carbon pool. According to the types of carbon pools considered, four different simulation scenarios were designed in this study. Scenario 1 only considers timber benefits, biomass energy benefits and operating costs; Scenario 2 adds additional biomass carbon pool; Scenario 3 further considers the impact of logging residue carbon pool; Scenario 4 adds the impact of carbon release penalties for commercial materials on the basis of Scenario 3. For each simulation scenario, the effects of different carbon prices, discount rates, biomass energy ratios and other factors on the optimal rotation, timber production, carbon sink and land expected value of L. olgensis plantation were quantified. Result: Under the baseline scenario (carbon price: 100 yuan·t^-1 C; discount rate: 5%; the proportion of branch and leaf biomass energy: 20%), the overall expected value of forest land showed a clear trend of first increasing and then decreasing with the increase of stand age, which can be simulated by quadratic multi pattern (Ra² > 0.60). The optimal rotation period for scenarios 1 to 4 was 35 a, and the corresponding forest land expected value was 50 288, 53 638, 53 263 and 53 071 yuan·hm^-2, respectively. For scenarios 2 to 4, the expect value of forest land increased by about 6.66%, 5.92% and 5.53% respectively compared to scenario 1. For Scenarios 2-4, the minimum carbon price that can extend the optimal rotation period of L. olgensis plantation by one year was 1, 500 and 1, 000 and 1000 yuan·t^-1 C, and the corresponding forest land expected values reached 100 667, 80 171 and 78 266 yuan·hm^-2, respectively, with an increase of 87.7%, 50.5% and 47.5% compared with scenario 1. When the discount rate increased from 5% to 9%, the optimal rotation age was advanced by about 4 years, and forest land expect value decreased by about 49 200 yuan·hm^-2. For the same discount rate, there was no significant difference between the optimal rotation period and the expected value of forest land under different simulation scenarios. Conclusion: Under the constraints of the current timber and carbon trading markets, timber revenue still dominates the management of Larix olgensis plantations absolutely. The increase of carbon pool types does not significantly change the optimal rotation age, but it has an impact on the forest land expected value. Carbon price and discount rate can significantly affect the optimal rotation period and land expected value of L. olgensis plantation. The minimum carbon price that can extend the optimal rotation period of L. olgensis plantation by 1 year should be at least 1 000 yuan. t^-1 C.

Objective: Taking Betula platyphylla in the Daxing'an Mountains as the research object, the volume model with form quotient was constructed and compared with the two-variable B. platyphylla volume model being used in the forestry production in northeast China and the traditional basic volume model. Combined with the biomass expansion factor, the effect of the form quotient on biomass was studied to provide a scientific basis for accurate prediction of individual tree volume and biomass. Method: 15 form quotients on the trunk were introduced into the traditional volume model to establish the two-variable and three-variable volume models, respectively. Specifically, the GNLS module of R software was used to fit the models, and variance functions were introduced to eliminate the heterosedasticity in the fitting process of each volume model. The mean percentage of bias(MPB), mean absolute bias(MAB), root mean square error(RMSE) and determination coefficient(R²) were used as evaluation indexes to compare and analyze each model, and the cross-validation method was used to validate the models. Result: 1) Introducing form quotient could significantly improve the fitting effect of volume model. When the relative tree height was 40%, the fitting effects of two-variable volume model and three-variable volume model with form quotient q_0.4 were the best. 2) The cross-validation results showed that the accuracy of volume prediction could be significantly improved by introducing form quotient into the volume model. Compared with the traditional two-variable model(2) and one-variable model(1), the RMSE of the three-variable model(15) and two-variable model(14) with form quotient were reduced by 38.9% and 45.8%, respectively. 3) Compared with the two-variable volume model(5) currently used in northeast China, the RMSE, MAB and MPB of the two-variable volume model(14) with form quotient was reduced by 46.7%, 40.2% and 47.7%, respectively; RMSE, MAB and MPB of the three-variable model(15) with form quotient was reduced by 59.1%, 59.2% and 64.1%, respectively. 4) Form quotient could significantly improve the prediction accuracy of biomass, The RMSE, MAB and MPB of the individual tree biomass model based on the three-variable model(15) with the biomass conversion factor(BEF) was reduced by 46.9%, 46.5% and 46.3%, respectively, compared with that of the basic model without the introduction of form quotient. Conclusion: The introduction of form quotient into the volume model could not only improve the prediction accuracy of individual volume, but also be helpful for the accurate prediction of individual tree biomass. The three-variable volume model(15) with form quotient might be more suitable for predicting Betula platyphylla individual volume and biomass in this area.

Objective: In this paper, the effects of different fertilization rates and models of nitrogen (N), phosphorus (P) and potassium (K) on photosynthetic characteristics, organic compound content and enzyme activities in leaves, and nutrients of Phoebe bournei seedlings were investigated, to reveal the mechanism of photosynthetic carbon fixation regulated by fertilization, which would provide a theoretical basis for the cultivation of strong seedlings and scientific fertilization of P. bournei. Objective: The "3414" field experiment was conducted to analyze the effects of different N, P, K fertilization treatments on photosynthetic pigment contents, photosynthetic indexes, leaf organic compound content and enzyme activities of P. bournei seedlings. The range analysis method was used to screen the best N, P, K fertilization model. The stepwise regression, correlation and path analysis method were used to construct the photosynthetic carbon fixation pathway regulated by fertilization. Result: 1) N, P, K fertilization increased the photosynthetic pigment content, photosynthesis, transpiration and water use capacity, reduced the contents of soluble sugars, soluble protein and malondialdehyde (MDA), increased the activities of nitrate reductase (NR), glutamine synthetase (GS) and acid phosphatase (ACP), inhibited polyphenol oxidase (PPO) activity, increased leaf starch content, and then promoted leaf carbon fixation of P. bournei seedlings. In the photosynthetic carbon metabolism, ACP, WUE and starch content were the key regulation points. 2) N element enhanced NR activity, increased chlorophyll a content, water use efficiency, and leaf carbon fixation of P. bournei seedlings. 3) P element increased chlorophyll b content, decreased MDA content, protected cell integrity, and improved carbon assimilation efficiency, but had no significant effect on the metabolism of photosynthate of P. bournei seedlings. 4) K element increased the contents of chlorophyll a and b, stomatal conductance, stomatal CO₂ and water use efficiency, starch content, and leaf carbon fixation of P. bournei seedlings. 5) Under the combined application of N, P and K fertilizer, the absorption of N, P and K was the most, which was significantly correlated with ACP activities, and was the most beneficial to photosynthetic carbon fixation, followed by the combined application of N and K fertilizer, and the smallest was single application of P fertilizer. The treatment effect of T6 (N: 0.532 g·plant^-1, P₂O₅: 0.133 g·plant^-1, K₂O: 0.356 g·plant^-1) was the best. Conclusion: After fertilization, P. bournei seedlings absorb N, P and K element, thereby increase the stomata ventilation, significantly improve the stomatal conductance, transpiration rate, and water use efficiency, increase net photosynthetic rate, photosynthetic product, and protein synthesis. Under the action of ACP enzyme, fertilization regulates carbon metabolism, and promotes the production of starch which can provide material and energy for growth of P. bournei seedlings.

Objective: In this paper, the light requirement and adaptation rules of the seedlings of Garcinia paucinervis, a rare and endangered plant, in karst mountains were studied, in order to provide a theoretical basis for its introduction, ex situ conservation, population rejuvenation, large-scale cultivation and ecological restoration of karst mountains. Method: The 3-year-old G. paucinervis seedlings were treated with different relative natural light intensities of 10%, 25%, 50% and 100% (marked as RI10%, RI25%, RI50% and RI100%, respectively) for two years. The dynamic changes of growth and leaf morphology features, biomass allocation, photosynthetic characteristics, photosynthetic pigment content in leaves and chlorophyll fluorescence parameters were compared, and the adaptation mechanisms of seedlings to different light environments were analyzed. Result: 1) After two years of light treatment, the ground diameter, plant height and crown width of RI25% and RI50% treatments were significantly greater than those of RI10% and RI100% treatments. 2) The individual leaf area and leaf thickness of RI25% treatment were the greatest in the 4 treatments. The biomass, specific leaf area and leaf area ratio increased first and then decreased with the increase of light intensity. The root mass ratio and root to shoot ratio of RI100% treatment were the greatest, and significantly higher than that of RI10% treatment. 3) In the first year, the order of the maximum net photosynthetic rate (P_max) and apparent quantum yield (AQY) were RI50% > RI25% > RI100% > RI10%. The light saturation point (LSP), light compensation point (LCP) and dark respiration rate (R_d) increased with the increase of light intensity. There were no significant differences in P_max and AQY values of RI50%, RI25% and RI10% in the second year, which however were higher than those of RI100% treatment. Except that the LSP of RI100% treatment was lower than that inthe first year, the LSP of the three shading treatments were higher than that in the first year. The highest value of net photosynthetic rate (P_n) in thewhole day was in the order of RI50% ≈ RI25% > RI10% > RI100%. In the most time of the whole day, P_n, stomatal limitation(L_s), water use efficiency(WUE) and light use efficiency(LUE) of RI100% treatment were lower than those of the three shading treatments, and the internal cellular CO₂ concentration(C_i) of RI100% treatment was higher than those of the three shading treatments. 4) With the increase of light intensity, the contents of chlorophyll a, chlorophyll b and carotenoids in seedling leaves decreased significantly.The ratio of carotenoids to chlorophyll in RI100% treatment was significantly higher than that in the three shading treatments. 5) In the second year, variable fluorescence(F_v), photochemical efficiency of PSII(F_v/F_o)and maximum photochemical efficiency(F_v/F_m), electron transfer rate(ETR) and photochemical quenching coefficient(q_P) were the highest in RI25% treatment, which changed significantly compared with the first year, while those parameters of RI100% treatment was significantly lower than the three shading treatments. Conclusion: G. paucinervis seedlings have the ability to adjust and adapt to the light environment in, the morphology and photosynthetic physiology. Seedlings grow slowly under stress in full light environment; Although the seedlings grow slowly under heavy shading, all photosynthetic physiological indexes are normal, indicating that they have adaptability to weak light; However, the seedlings grow well under 25%~50% relative light intensity, and their seedling leaves can make full use of light energy by increasing the absorption capacity of light energy and the photochemical efficiency of PSⅡ. G. paucinervis seedlings cultivation needs moderate shade. It is speculated that the strong light stress caused by deforestation is one of the environmental factors for G. paucinervis endangerment.

Objective: This study was conducted under the controlled experimental conditions in the phytotron. The effect of different tree species collocations on negative air ion (NAI) and the relationship between leaf nutrient elements and the NAI were investigated, in order to explore the mechanism of NAI production in the forest and provide a theoretical reference for the selection of tree species and their collocation in the future healthy forest. Method: The NAI concentrations of six typical subtropical tree species and their collocations were continuously monitored in a phytotron at the Hushan Experimental Base, Qianjiang Source Forest Ecology Station, Hangzhou, Zhejiang, China from June to September 2018. At the same time, the leaf element content was measured. One-way ANOVA and LSD multiple comparisons (α=0.05) were used to test the collected data, and the correlation between NAI concentration and leaf nutrient content was analyzed using Person's analysis. Result: The contents of manganese and potassium ions in plant leaves were significantly positively correlated with the NAI concentration (P < 0.05), the content of iron ion in broadleaf leaves was significantly positively correlated with the NAI concentration (P < 0.01), and the contents of nitrogen and copper ions in coniferous species were significantly positively correlated with the NAI concentration (P < 0.01). Different collocations of tree species led to significant differences in NAI concentration, and there was a tree species mixing interaction. The interaction showed a positive effect when the mixed species were two and four species, and the interaction effect on NAI increased with increasing leaf area and average NAI concentration of single species. The interaction showed a negative effect when the mixed tree species were five and six species. At mixed species of 2-6 species, the interaction effect showed a tight non-linear increasing relationship with the leaf biomass of each species mixed treatment, with the regression equation y = -0.063 1x² + 78.322x – 23 783. Conclusion: For raising the NAI concentration around plants, the contents of manganese and potassium ions in leaves have a positive effect, and the content of iron ion in broad-leaved leaves and the contents of nitrogen and copper ions in coniferous leaves have a more significant effect. The quantitative composition of different tree species leads to differences in NAI concentration, and interaction effects are influenced by leaf biomass, leaf area, tree height collocation, and individual tree species NAI effects. Overall, the NAI concentration effect of the tree species collocation depends on their interaction, with coniferous species being more conducive to elevate NAI concentration and species with high NAI effects being more conducive to elevate NAI concentration when they are in the uppermost space of the collocation. The research on NAI concentration effect of tree species collocation and leaf element content would provide a scientific basis for tree species selection and structural collocation of efficient recreational forests.

Objective: Genetic testing is an important approach for genetic improvement of forest trees and can be used to estimate genetic parameters and select elite trees. This study is to explore the effects of different models by combining spatial and competition effects on the estimation of genetic parameters of growth traits in Chinese fir (Cunninghamia lanceolate) at different forest age stages, in order to provide a theoretical basis for improving the accuracy of breeding value prediction and selection of elite trees. Method: This study was conducted in a 40-year-old open-pollinated progeny trial forest in the Yangkou State Forest Farm in Fujian Province, and a mixed linear model was used to fit the effects of experimental design, spatial, competition, spatial-competition effects for diameter at breast height (DBH) and tree heights measured at different tree ages from the 40-year-old Chinese fir trial. The Akaike information criterion (AIC) was used to evaluate different models, and compare genetic parameters and breeding values of the different models. Result: 1) The spatial-competition effect of fit increased by an average of 39.72% of the narrow heritability estimates of growth traits. The additive genetic variance component of DBH in the mixed spatial-competition model increased 4.46%, 26.95% and 35.87% compared to that of the standard mixed linear model (MLM), spatial model, and competition model, respectively. While the residual variances of DBH in the mixed spatial-competition model decreased by 21.95%, 26.81% and 20.19% compared to those of the standard mixed linear model, spatial model, and competition model, respectively. The additive genetic variance of the tree height in the spatial-competition model was 10.73% and 1.22% higher than that in MLM in 1991 and 2020, respectively, and the residual variance decreased by 12.75% and 33.83%, respectively. 2) The intensity of competition was related to the distance between stand individuals. The residual correlation among individuals showed that the competition effect of growth traits in the same row and column was significantly higher than the competition effect of individuals in the diagonal direction. 3) There was a competitive effect on growth traits, and diameter growth was greater than tree height growth. The additive-competitive effect correlation of the same trait showed that the growth traits of Chinsese fir showed a competitive effect at different forest ages, and the competitive effect of diameter growth was greater than that of high growth at the young forest age stage; the growth traits at the middle forest age stage showed a strong competitive correlation, and combined with the residual correlation results, it showed that the growth traits of Chinsese fir showed a strong competitive effect in the middle forest age. The competitive influence among individual chest diameters was greater than the competitive influence between tree height, and DBH was more sensitive to competition than tree height. 4) The accuracy of the breeding values was 0.559 under 5% selection rate, and 23 individuals were selected, among them, 78.3% of individuals were replicated. The mean values of DBH of standard MLM, spatial model, competition model and spatial-competition were 37.3, 37.2, 37.3, 37.3 cm, respectively. and genetic gains of DBH for the selected individuals were 12.73%, 13.86%, 13.32% and 14.37%, respectively. Conclusion: Using competition-spatial model improves the accuracy of genetic parameter estimation. It is showed that the competition of individual plants in the diagonal direction is weaker than that of individual plants in the row and column directions. The growth traits at middle stand ages are most affected by competition, DBH is more sensitive to competition than tree height.

Objective: This study aims to study the genetic variation of growth and form-quality traits of Schima superba young plantation under two different plantation patterns: pure plantation and mixed plantation with Cunninghamia lanceolata, so as to provide a theoretical basis for the selection and efficient breeding of superior varieties of S. superba. Method: This experiment was conducted in a 7-year-old S. superba family-test trial forest that was established in 2014 in Yanping District, Nanping City, Fujian Province, under two planting modes of pure plantation and mixed plantation with C. lanceolata (S. superba∶C. lanceolata 1∶2 column mixture). The family genetic variation of its growth and form-quality traits was analyzed, and the genetic parameters were estimated and the correlation analysis was conducted. Result: The growth and form-quality traits of S. superba families were significantly affected by the two plantation patterns of pure and mixed plantation (P < 0.05), and the block effect was also significant. Compared to the pure plantation pattern, the mixed with C. lanceolata significantly promoted the phenotypic differentiation of growth and form-quality traits of S. superba family. The values of tree height, diameter at breast height, crown width and stem straightness were increased, which were 18%, 16% and 15% higher than those in the pure plantation pattern, respectively. The number of forks in trunk decreased significantly, which was only 78% of that in the pure plantation pattern. In the pure plantation pattern, S. superba traits were generally controlled by weak to strong family genetic control (0.18-0.53) and weak individual genetic control (0.03 ~ 0.13). When being mixed with C. lanceolata, the estimated values of family heritability and individual plant heritability of S. superba traits were generally improved. Especially, the heritability of tree height, diameter at breast height, number of forks in trunk and stem straightness were 31%, 72%, 20% and 31% higher than that of pure plantation, respectively. There were different genetic responses to growth and form-quality traits of S. superba under the two plantation patterns. The growth performance and rank change of S. superba families were significantly changed when being mixing with C. lanceolata. Correlation analysis showed that there was no significant correlation between growth traits and form-quality traits (except the height under branches) of S. superba families under the two plantation patterns. Growth and form-quality traits seemed to be independent of each other. The relationship among tree height, diameter at breast height and the under branch height was close and not affected by plantation pattern. Mixing with C. lanceolata not only affected the growth of S. superba crown, but also effectively weakened the relationship between the maximum branch angle, the height under branches and the maximum branch diameter, as well as the influence of the number of branching branches on the stem straightness. The relationship between tree height, diameter at breast height and the height under branch was not easily affected by plantation pattern, but the relationship between crown width and diameter height, the relationship between maximum branch angle, the height under branches and maximum branch diameter, and the relationship between the number of forks in trunk and the stem straightness were all weakened by mixing with C. lanceolata. Conclusion: The growth and form-quality traits of S. superba families are significantly affected by pure and mixed plantation. The mixed plantation with C. lanceolata can promote the phenotypic differentiation of S. superba families, and improve the estimated heritability of growth and form-quality traits in families and individuals. For the construction of S. superba plantation, it is necessary to select suitable and good S. superba families for plantation according to the habitat conditions and cultivation patterns, and to prune and remove the excess branches of S. superba timely to cultivate high quality wood.

Objective: Eucalyptus can tolerate the heavy metal toxicity tosome extent, in which metal tolerance proteins play an important role. In this study, we screened a metal tolerance protein gene EgMTP6 from Eucalyptus grandis and analyzed its bioinformatics characteristics, subcellular localization, zinc transport function and expression pattern, in order to reveal the relationship between arbuscular mycorrhizal fungi, zinc, phosphorus and EgMTP6, and to explore the role of EgMTP6 in alleviating zinc stress. Method: Through bioinformatics analyses, the gene nucleotide and amino acid sequence characteristics of EgMTP6 were obtained. Subcellular localization of EgMTP6 was analyzed by expressing EgMTP6 inepidermal cells of tobacco leaves, and the zinc transport function was analyzed by yeast mutant complementation. The effects of zinc (ZnSO₄), phosphorus (NaH₂PO₄) and Rhizophagus irregularis on the expression of EgMTP6 were analyzed by qRT-PCR. Result: In this study, bioinformatics analyses displayed that EgMTP6 contained an open reading frame in a length of 1 524 bp, which encoded 507 amino acids, including 12 exons and 11 introns. The tructural prediction showed that the N-terminal of EgMTP6 protein was located in the cytoplasm and the C-terminal was located in the extracellular. The protein contained five transmembrane domains and the HD-HD motif. Phylogenetic analysis showed that EgMTP6 was in Group 6 and belonged to Fe/Zn-CDF. Multiple-sequence alignment showed that MTP6 contained FieF domain (Ferrous-iron efflux pump, FieF). Subcellular localization analysis of tobacco leaves illustrated that EgMTP6 was located in the endoplasmic reticulum. Yeast mutant complementation showed that EgMTP6 was a zinc transporter. Fluorescence quantitative results showed that the expression of EgMTP6 was not affected byzinc, but induced by high concentration of phosphorus, and R. irregularis. Conclusion: EgMTP6 belongs to Fe/Zn-CDFgroup andit is involved in the zinc transport. Its expression is unaffected by zinc concentration, but is induced by high concentration of phosphorus, and R. irregularis. This investigations on molecular characteristics and function of EgMTP6 will be helpful to future studies on the molecular mechanism of heavy metal tolerance of arbuscular mycorrhizal in Eucalyptus grandis.

Objective: This study aimed to explore the species composition, diversity and functional group characteristics of fungal community in three vegetative organs and rhizosphere soil of Ligustrum lucidum, so as to lay a foundation for the privet-fungi interaction study and the development and utilization of the privet endophytic and rhizosphere fungal resources.This research could provide a reference for the study of trees microbiome. Method: The leaf, stem, root and rhizosphere soil of L. lucidum were selected as research objects, and the ITS1 region of fungal rRNA gene was sequenced by Illumina MiSeq instrument. Based on the sequencing result, the diversity, species composition, functional group characteristics and their difference in community structure of fungal community in three vegetative organs and rhizosphere soil were analyzed subsequently. Result: The species richness of fungal community of different samples was in the order of RS>SE>RE>LE, and the community diversity was RS>LE>SE>RE. There were 31 OTUs in the four samples, accounting for 2.08% of the total OTUs. Approximately 39.42%, 35.26% and 76.94% of OTUs in leaves, stems and roots were also found in rhizosphere soil, respectively. The β diversity analysis showed that the fungal community structure of leaf was relatively similar to that of stem, but was different from that of root and rhizosphere soil. At the phylum level, the dominant taxon of fungi in the four compartments were Ascomycota and Basidiomycota. At the genus level, the dominant fungi of endophytic fungi community in leaves and stems were Cladosporium and Vishniacozyma while the dominant fungi in the root were Rhexodenticula and Pochonia. In addition, the dominant fungi of rhizosphere soil were Psilocybe and Saitozyma.The common fungi in leaves, stems, roots and rhizosphere soil mainly were Cladosporium, Vishniacozyma, Saitozyma, Rachicladosporium, Symmetrospora, Alternaria and Penicillium. The statistical result of fungi functional group classification showed that the differentiation characteristics of samples could be divided into aboveground and underground parts with the fungi in leaves and stems were mainly of compound trophic (pathotrophy-saprotrophy-symbiotrophy, pathotrophy-saprotrophy), which accounted for 76.97% and 91.68%, respectively, while those were mainly of single trophic fungi (saprotrophy, symbiotrophy) in root and rhizosphere soil, accounting for 60.05% and 67.51%, respectively. Conclusions: The diversity of fungal community in rhizosphere soil is significantly higher than that in leaves, stems and roots of L. lucidum. The fungal community structure and functional group characteristic of leaves are relatively similar to that of stems, but significantly different from those of roots and rhizosphere soil. The fungi functional group in leaves and stems is mostly pathotrophy-saprotrophy-symbiotrophy, while that in root and rhizosphere soil is mostly saprotrophy.

Objective: In this study, we investigated the influence of different host tree species on the types of symbiotic fungi of Sirex nitobei, and the antagonistic effect of dominant fungi on the body surface of the dead S. nitobei larvae in the host Pinus sylvestris var. mongolica on symbiotic fungi of S. nitobei, in order to explore the causes of death of S. nitobei larvae in the host tree from a microscopic perspective, so as to offer new ideas and basis for biocontrol of S. nitobei. Method: According to morphological characteristics and ITS sequences, the species of symbiotic fungi in different host tree species were identified, and the antagonistic ability of dominant endophytic fungi of Phlebiopsis gigantea and Trichoderma viride against symbiotic fungi (Amylostereum chailletii and A. areolatum) of S. nitobei was determined by plate confrontation, fermentation broth test and microscopic observation. Result: The symbiotic fungi of A. chailletii and A. areolatum were isolated from different host tree species, but the detection rates of two symbiotic fungi of S. nitobei were significantly different. The wasps in P. sylvestris var. mongolica were more likely to carry A. chailletii, while the wasps in P. tabulaeformis were easier to carry A. areolatum. The growth rate of the two endophytic fungi was faster than that of symbiotic fungi, of which Trichoderma viride had the fastest growth rate and symbiotic fungus of A. areolatum had the slowest growth rate. Both Trichoderma viride and Phlebiopsis gigantea were able to inhibit the growth of symbiotic fungal hyphae, and they wrapped, parasitized or interspersed on the symbiotic fungal hyphae, resulting in the distortion, deformation and abnormal expansion of symbiotic fungal hyphae. Eventually, the two endophytic fungi completely covered the colonies of symbiotic fungi, which caused the symbiotic fungi to be unable to grow and die. The fermentation broth of two endophytic fungi inhibited the conidial germination of symbiotic fungi of A. chailletii and A. areolatum. The inhibitiory effect of Trichoderma viride fermentation broth was higher than that of Phlebiopsis gigantea fermentation broth, furthermore, the higher the dilution ratio of fermentation broth, the worse the inhibitory effect. Conclusion: The two endophytic fungal species have strong antagonistic effects on the symbiotic fungi of S. nitobei, and these endophytic fungal hyphae can completely inhibit and kill the symbiotic fungal hyphae. The research results would provide available fungal strains for the biological control of S. nitobei.

Objective: This study aims to clarify the bioinformatics of HrWRKY53 gene and its role in sea-buckthorn resisting Rhagoletis batava obseuriosa(RBO), so as to lay a foundation for the analysis of insect resistance mechanism and molecular breeding of Elaeagnaceae such as Hippophae rhamnoides. Method: Based on the transcriptome data of sea-buckthorn fruits before and after RBO infestation, the key differentially expressed gene HrWRKY53 involved in the damage of sea-buckthorn were explored from members of HrWRKY gene family. Bioinformatics analysis was carried out to analyze the secondary structure and hydrophobicity and to predict the phosphorylation sites. In the NCBI website, the protein sequences with high homology were searched by BLASTP for sequence alignment, and the phylogenetic tree was constructed. qRT-PCR was used to detect the tissue expression specificity of the gene and the gene expression pattern before and after RBO infestation and under the treatment of abscisic acid (ABA), methyl jasmonate (MeJA) and ethylene (ET). The expression levels of HrJA2, HrLOX1, HrAOS and HrAOC in the JA signal pathway in response to the damage of RBO were analyzed, and their correlation with the expression of HrWRKY53 was was analyzed. Result: The open reading frame (ORF) of HrWRKY53 gene obtained from sea-buckthorn transcriptome was 1 302 bp, which encoded 433 amino acid residues. HrWRKY53 protein included two WRKY conserved domains and C2H2 zinc finger structures, and belonged to the family of type I WRKY transcription factors. The secondary structure prediction showed that HrWRKY53 was mainly composed of random curl and contained 141 threonine phosphorylation sites, which could be closely related to phosphorylation. The hydrophobicity prediction showed that the protein belonged to a hydrophobic protein. Phylogenetic tree analysis displayed that the gene had the highest homology with FvWRKY25. qRT-PCR showed that the gene had obvious tissue expression specificity, and its expression was the highest in sea-buckthorn fruit. The gene expression increased significantly under RBO infestation, mechanical injury, treatments with ABA, MeJA and ET, among which the expression increased most significantly after JA induction. In addition, the analysis of key differentially expressed genes involved in JA signal pathway based on transcriptome data and fluorescence quantitative data showed that the expression of HrJA2 gene in JA signal pathway increased most significantly, and there was a significant positive correlation between HrWRKY53 and HrJA2. Conclusion: HrWRKY53 of Hippophae rhamnoides belongs to the family of type I WRKY transcription factors and has the highest homology with FvWRKY25 of strawberry in Rosaceae. This gene is involved in the response to RBO and hormone-induced. The expression of HrJA2 can be induced to promote JA synthesis, and then increase the expresses of HrWRKY53 in sea-buckthorn, to further improve the ability of seabuckthorn to resist RBO.

Objective: Yponomeuta padella is a defoliator and one of the main pests in wild fruit forest of Western Tianshan Mountains in Yili Valley, Xinjiang. Investigation on its parasitic natural enemies could lay a foundation for the biological control of the pest. Method: The larvae and pupae of Y. padella were collected in the occurrence place during the field investigation from 2016 to 2017 and artificially reared in the laboratory, in which its life history and morphological characteristics were observed. The parasitic natural enemies of the pest were classified and identified, and the biological characteristics of dominant parasitoids were recorded. Result: 1) The life history of Y. padella was clarified, and five parasitic enemies of Y. padella, including four parasitic wasps and one parasitic fly, Tachinidae, were obtained. Among them Ageniaspis fuscicollis and Bessa parallela attacked its larval stage, Monodontomerus sp., Iseropus sp. and Aprostocetus sp. attacked the pupae. 2) Through the comparison of parasitism rate, A. fuscicollis was considered as the dominant parasitic natural enemy of Y. padella, with an average parasitism rate of 69.77%, and could be a potential biological control agent of this pest. The ratio of female to male was about 3.5∶1. The development process of A. fuscicollis was preliminarily clarified. 3) The parasitic wasp in the pupal stage of Y. padella was recorded for the first time. Conclusion: In this study, we have found out the parasitic natural enemy resources of the main apple pest, Y. padella, and determined the development period, parasitic rate and sex ratio of dominant parasitoid A. fuscicollis, and firstly recorded Aprostocetus sp., the pupal parasitic natural enemy of the pest. All the results will provide important references for the protection of the biodiversity of the natural enemies in wild fruit forest and for biological control of the pest by using native natural enemies.

Objective: The objective of this study was to analyze synergistic flame retardant mechanism of magnesium-aluminum layered double hydroxides(MgAl-LDHs) and melamine phosphate(MP), and to provide theoretical bases of MgAl-LDHs and MP compound flame retardant for fiberboard. Method: The flame retardant performance of medium density fiberboard was tested using oxygen index meter and cone calorimeter. The synergistic effect on heat release performance and smoke generation characteristics of compound flame retardants was performed through synergy ratio of limiting oxygen index (LOI), heat release rate(HRR), total heat release(THR), smoke production rate(SPR) and total smoke release(TSR). Furthermore, the thermogravimetric, fourier infrared spectroscopy and thermogravimetric-fourier infrared spectroscopy combined techniques were used to discuss the condensed phase and gas phase flame retardant mechanisms between MgAl-LDHs and MP. Result: The oxygen index of medium density fiberboard that produced with MgAl-LDHs and MP compound flame retardant was 31.9%. The compound flame retardant did not show a synergistic effect in the calculation of the oxygen index synergy ratio. However, the ratio calculation of cone calorimeter showed a synergistic effect. The pyrolysis analysis showed that the flame retardant effect of compound flame retardant on wood powder was better than that using MgAl-LDHs or MP alone. During the combustion process, MP catalyzed MgAl-LDHs rapid decomposition to release a large amount of water vapor and carbon dioxide, and to absorb the heat of the medium density fiberboard to further reduce the surface temperature. The result led to the combustion difficult to maintain, and simultaneously water vapor and carbon dioxide diluted the combustible gas and oxygen concentration for reducing combustion rate. The flame retardant mechanisms of compound flame retardant were mainly the gas phase flame retardant, and there was not an obvious condensed phase. The gas phase flame retardant was the result of the combined action from a cooling effect and a dilution effect. The compound flame retardant was mainly gas phase flame retardant before 320 ℃ and transformed into condensed phase flame retardant after 380 ℃. Conclusion: The synergistic mechanisms of MgAl-LDHs and MP compound flame retardant shown in three aspects: 1) The decompose temperature range of compound flame retardant was increased and its initial decompose temperature was 198 ℃, meaning that the MgAl-LDHs would decompose in a lower temperature. 2) MgAl-LDHs and MP were released a large amount of water vapor, carbon dioxide and ammonia gas during thermal decomposition, these gas diluted the combustible gas on combustion surface and presented dilution effects. 3) Synergistic effect of MP catalyzed carbon formation and MgAl-LDHs high temperature melting coverage.

Objective: This study aims to rationally grade forest land, establish a forest land benchmark price, and solve the problem of difficulty in forest land resource asset evaluation and accounting, in order to improve the efficiency of large-scale forest land value evaluation. Method: Based on the survey data of forest resource planning and design in Longquan county, Zhejiang Province in 2016, the factor method was used for forest land grading. Firstly, natural factors, socioeconomic factors and location factors were selected, and the entropy method was used to determine the weight of each factor index, and a weighted sum model was used to calculate the grading index, and finally the total score axis determination method was used to grade the forest land. The forest land benchmark price was calculated and determined by the forest land expected price method. Result: 1) The forest land resources in the study area were divided into 4 grades. The number of small classes and the total area increased and then gradually decreased from grade 1 to grade 4. The distribution of forest land grades was in a normal distribution and the structure was reasonable; 2) The benchmark price of forest land in the study area for level 1 to level 4 was 10 504, 8 978, 7 631 and 6 284 yuan·hm^-2, respectively. The level of the benchmark price of each grade of forest land reflected the quality of the forest land; 3) According to the particularity of the forest land, combined with the external manifestation of the forest land productivity level, a price correction coefficient that matches the forest land benchmark price was formulated; 4) The total economic value of forestland resource assets in the study area combined with forestland benchmark and price correction coefficient is 2 456 million yuan. Conclusion: The distribution characteristics of forest forestland at all grades indicate that the grading results of forest land accord with the characteristic of the differences in quality and value. The use of forestland benchmark price for forest resource asset to account the economic value in the study area has high applicability. The research results can provide method choice for accounting the value of large number of forestland resources, and the technical support for the preparation of balance sheet of natural resources.

Objective: Based on the perspective of the risk coupling effect of forestry carbon sink projects, the risk level was measured and evaluated in this study, in order to provide decision-making reference for the risk supervision of project operators and government departments. Method: A questionnaire of 113 forestry carbon sink experts from different fields was conducted on the risk categories, risk occurrence probability and influence degree of forestry carbon sink projects. Firstly, the project risks were classified concretely, and the project risk list was formed, including 4 risk subsystems such as nature, technology, market and policy, with a total of 22 risk factors. Then, according to the literature and combined with the characteristics of forestry carbon sink project, the coupling relationship between risk factors within and among risk subsystems of forestry carbon sequestration projects was analyzed in detail. A system dynamics model for risk assessment of forestry carbon sequestration projects was constructed on the basis of risk coupling diagram and risk stock-flow diagram. All parameters of system dynamics operation were obtained, and VENSIM software was used to measure and evaluate the overall risk level and coupling effect of the project by scenario simulation method. Result: 1) The coupling effect had a significant impact on the risk assessment result of forestry carbon sink projects, and the intensity of homogeneous coupling effect iwasgreater than heterogeneous coupling effect. When both homogeneous coupling and heterogeneous coupling effects were considered, the overall risk level of forestry carbon sink projects was 6.784, and the risk level is III. However, when both homogeneous coupling effect and heterogeneous coupling effect were not considered, only heterogeneous coupling effect or homogeneous coupling effect was considered, the overall risk level of forestry carbon sink projects decreased to 0.355, 0.929 and 3.102 respectively, and the risk levels changed to I, I and II respectively. 2) The coupling effects of different risk subsystems were obviously different. Specifically, under three different scenarios, in which only homogeneous coupling effect, heterogeneous coupling effect and two coupling effects were considered simultaneously, the order of coupling effect of each risk subsystem was market risk > policy risk > technology risk > natural risk. 3) Only considering the homogeneous coupling scenario, the coupling effect of "carbon sink price change and carbon market supply change" was the strongest. Only considering the heterogeneous coupling effect, the coupling effect of "the change of national emission reduction policy and the change of carbon market supply" was the strongest. Considering the two coupling effects at the same time, the coupling effect of "the change of national emission reduction policy and the change of carbon market supply" was the strongest. 4) In terms of risk level and coupling effect, the market and policy risks were relatively large, while the technical and natural risks were relatively small, but the heterogeneous coupling effect can gradually enlarge the overall risk of the project. Conclusion: In the risk supervision of forestry carbon sink projects, we should not only pay attention to the risk level itself, but also attach importance to the coupling effect between risks, and guard against the evolution between risks and the rise of the overall risk level from the source.

The interconnected pore network within wood is the main way of water migration and chemical penetration, which plays a decisive role in wood drying, wood impregnation and modification, and is also an important factor to affect the functional properties of wooden products, such as sound absorption, thermal insulation and humidity control. However, at present the main evaluation indexes of wood pore structure are porosity, pore size distribution, pore volume, density, specific surface area, pore morphology and fractal dimension, etc., and no comprehensive and systematic studies have been carried out on the evaluation of pore connectivity. In this paper, the research on the evaluation of wood pore structure and pore connectivity with three types of pore characterization techniques, those are the adsorption analysis method, the nuclear magnetic resonance method as well as the computed tomography three-dimensional imaging method, is reviewed and summarized. Furthermore, scientific problems and prospects are proposed as follows: 1) Construction of wood pore connectivity evaluation system: firstly, to form the evaluation theory basis and research method of wood pore connectivity, that is to evaluate and verify the applicability and accuracy of existing methods, and further modify the theoretical model and optimize the corresponding evaluation method based on wood pore characteristics. Secondly, to facilitate the research on the evaluation scope and evaluation index quantification by combination and complementarity of various characterization technologies for the integrity and comprehensiveness of wood pore connectivity evaluation system. 2) Interpretation of the topological structure of wood pore space: the pore space of wood is a very complex internal topological structure with different pore distributions and pore connectivities in the longitudinal, radial and tangential directions, and greatly distinct pore sizes as well as diverse morphologies which are cross-linked differently. The evaluation of wood pore connectivity will provide a wider perspective on the interpretation of wood pore topological structure. On the basis of the full refining of the characteristic index parameters, and combined with data mining technology, the wood pore topological structure will be comprehensively interpreted through deep analysis for the potential relationships and rules of the characteristic index data, so as to promote the upgrading and optimization of the traditional characterization technology and evaluation system.

Objective: The CSR (complete spatial randomness) null model of the point pattern analysis requires that the habitat background is homogeneous, but the most factors in natural forest habitat are heterogeneous, which will inevitably influence the point pattern analysis. This paper attempts to divide the heterogeneous plots into several relatively homogeneous subareas by the method of habitat division, and discusses the interaction rules among individual trees in different habitat subareas through the analysis of mark point pattern, in order to provide theoretical support for the management and operation of forest management. Method: Based on the data of 21.12 hm² natural mixed broadleaved-conifer forest, the forest plot was divided into two relatively homogeneous habitats (A and B) according to the topographic variables. The interaction effects between adjacent individuals were tested by using mark correlation function combined with the complete spatial randomness simulation process. Result: The mark correlation analysis of individual tree species showed that the vast majority of tree species in areas A and B showed negative spatial correlation between individual DBHs. Moreover, at the scale of r < 6 m, the number of tree species with negative correlation in area A was significantly higher than that in area B. At the scale of r < 9 m, no positive correlation between the individual DBHs was detected. Without considering the heterogeneity of habitat conditions, mark correlation analysis was carried out in the whole sample plot. At the scale of 0-8 m, the individual DBHs of canopy layer showed a significant negative correlation, and there was no significant spatial correlation between those of subcanopy layer and understorey layer. When the spatial autocorrelation of the attributes of individual DBHs in each forest layer was tested in a relatively uniform habitat, there was no significant spatial correlation between the individual DBHs of the sub-canopy layer and the understory layer, while those of the canopy layer had significant negative correlation at small scale. The interaction scale of the canopy individuals in area A was 0-6.9 m, and that of area B was 0-5.6 m. Conclusion: Under different habitat conditions (i.e., subzone A and B), the spatial negative correlation scales of DBH of adjacent individuals in the forest canopy are different. Therefore, in the process of forest management, the influence of habitat differences should be fully considered when determining the final stocking density of retained trees.