Objective: This study aimed to explore the mechanism of Silicon (Si) in increasingthe cold resistance of red sandalwood (Pterocarpus santalinus) seedlings by improving mineral nutrient absorption and distribution. Method: One-year-old seedlings were treated with two levels of Si amount for 6 months, and the variations of 8 mineral elements in the seedlings were measured. Then the seedlings were gradually cooled down to (-3±0.5)℃ and treated with the temperature for 24 h, and 72 h, respectively, and the intracellular concentrations of H⁺and Ca²⁺, and H⁺-ATPases and Ca²⁺-ATPase activities of plasma membrane and thylakoid membrane were detected. Result: The results showed that the relative content of K element of red sandalwood seedlings with Si addition was significantly reduced, and the relative content of Si element, and especially Ca element was significantly increased compared with the control. The activities of plasma membrane H⁺-ATPase and Ca²⁺-ATPase of Si-treated seedlings were significantly higher than those of control, and their reductions were significantly less under low temperature stress, especially for the plasma membrane H⁺-ATPase. Under low temperature stress, the protein content and H⁺-ATPase and Ca²⁺-ATPase activities of thylakoid membrane of control seedlings significantly decreased, while phospholipase-D (PLD) activity significantly increased. Statistical analysis showed that H⁺-ATPase and Ca²⁺-ATPase activities were closely related to Ca²⁺ content, membrane lipid composition and PLD activity. Objective: Application of Si improved the absorption, distribution and balance of mineral elements in red sandalwood seedlings, Si mediated the stability of ion pump activity and other chemical components of plasma and thylakoid membranes of red sandalwood seedlings under low temperature stress.

Objective: In this study we measured the morphology and photosynthetic parameters of Carya illinoinensis at different development stages. Furthermore, DCMU, an inhibitor of photosynthesis, was applied to detect the effect of photosynthesis inhibitionon the fruit dry weight. The purpose of this study was to explore the influence of photosynthesis of Pecan pseudo-peel on the fruit dry matter accumulation, which could lay a foundation for further study on potential and advantage of photosynthesis of pseudo-peel of pecan, and provide atechnical basis for further improving the yield of pecans. Method: In this study, pecan fruits were used as the experimental material.The dynamic changes in dry/fresh mass, surface area, chlorophyll content, the activity of RuBPC (ribulose 1, 5-bisphosphate carboxylase) and PEPC (phosphoenolpyruvate carboxylase) of pecan fruits were investigated at the critical stage of fruit development.In addition, DCMU was applied once a week from July 25^th (75DAP)to the fruits harveston September 12^th to inhibitthe fruit photosynthesis, and the dynamic changes in fruit length/width, fresh/dry weight of nutlet, and oil content weremeasured to detect the effect of DCMU treatment on fruit dry matter.Result: 1) From 80 to 120 DAP, fresh weight, dry weight and surface area of pecan fruits increased by 579.33%, 447.74% and 227.39%, respectively (P < 0.01). 2)From 80 to 120 DAP, the photosynthetic rate (P_g) decreased by 24%with PAR of 1 300 μmol·m^-2s^-1, however, there was no significant change in stomatal conductance (G_s) and intercellular carbon dioxide concentration (C_i) (P>0.05).3)The chlorophyll content of the pseudo-peel of pecan fruit was significantly reduced by 63.15% (P < 0.05).The activity of RuBPC and PEPC decreased by 56.25% (P < 0.05) and 48.78% (P < 0.05), respectively, while the content of soluble protein did not change significantly (P>0.05).4) The maximum photochemical efficiency (F_v/F_m), the actual photochemical quantum efficiency (Y (Ⅱ)), the ratio of the PSⅡ reaction centers (q_P)and the electron transfer rate (ETR)in the pseudo-peel of pecanfruits were not significantly changed (P>0.05)at PAR of 1 801 μmol·m^-2s^-1. 5) After DCMU treatment, the fruit length and width decreased by 5.07% (P < 0.05) and 4.56% (P < 0.05), the dry weight and fresh weight of nutlet decreased by 12.29% (P < 0.05)and 14.97% (P < 0.05), respectively, and the oil content decreased by 2.48% (P < 0.05). Objective: The results indicated that with the growth of fruits, the photosynthetic capacity of pseudo-peel of pecan fruits was significantly reduced. From 80 to 120 DAP, the decrease in P_g might be due to the decreased chlorophyll content, RuBPC enzyme and PEPC enzyme activity of the pecan fruits' pseudo-peel. However, the chlorophyll fluorescence parameters did not change significantly, and the photosynthetic apparatus of the pseudo-peel was stable. The fruit size and quality decreased significantly after DCMU treatment. Photosynthesis of the pseudo-peel plays an important role in dry matter accumulation of Pecan fruits.

Objective: The objective of this study was to determine anthocyanin components and contents in petals of Camellia japonica 'Chidan' and its bud mutation cultivars, and to clarify the material basis of their color formation by combining with phenotypic analysis of flower colors, then reveal their relationship between anthocyanin components and flower colors and provide the basis for the bud mutation breeding of flower colors in C. japonica. Method: Flower colors were measured by CIE L^* a^* b^* scale, and anthocyanin components and contents were measured by high-performance liquid chromatography coupled with diode array detection (HPLC-DAD) and ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). The relationship between flower colors and anthocyanin components was explored by multiple liner regression analyses.Result: Seven anthocyanin components were detected in C. japonica 'Chidan' and its bud mutation cultivars, that were cyanidin-3-O-β-galactoside (Cy3Ga), cyanidin-3-O-β-glucoside (Cy3G), cyanidin-3-O-(6-O-(E)-caffeoyl)-β-galactoside (Cy3GaECaf), cyanidin-3-O-(6-O-(E)-caffeoyl)-β-glucoside (Cy3GECaf), cyanidin-3-O-(6-O-(Z)-p-coumaroyl)-β-glucoside (Cy3GZpC), cyanidin-3-O-(6-O-(E)-p-coumaroyl)-β-galactoside (Cy3GaEpC) and cyanidin-3-O-(6-O-(E)-p-coumaroyl)-β-glucoside (Cy3GEpC). Anthocyanins were not detected in petals of C. japonica 'Yudan', and Cy3GECaf were not detected in C. japonica 'Jinbi huihuang'. Objective: Flower color was intensified with the increase of the contents of main anthocyanin components and total anthocyanin of C. japonica 'Chidan'and its bud mutation cultivars. The main anthocyanin components were Cy3G and Cy3GEpC in pink and red petals, and Cy3G and Cy3Ga in dark red petals. The increase of proportions of Cy3Ga and Cy3G in petals of C. japonica 'Chidan'and its bud mutation cultivars caused intensification of the flower colors. Cy3G and Cy3GEpC were the main anthocyanins which determined the red color of petals in C. japonica 'Chidan' and its bud mutation cultivars, and the accumulation of their contents significantly intensified red color of the petals.

Objective: In order to provide a scientific monitoring result and diagnostic basis for the temporal and spatial variation of vegetation cover in Guangxi, the change characteristics of vegetation cover and its key factors from 2006 to 2016 were explored. Method: The whole changes of vegetation cover in Guangxi were explored through trend analysis method based on MOD13Q1. The relationships between vegetation cover change and temperature and precipitation were explored through regression analysis method. The effects of human activities on the vegetation cover change reflected by MODIS land cover data were analyzed by using difference method between remote sensing images in different phases.Result: Guangxi's vegetation coverage was increasing with fluctuation during the past 11 years. The NDVI has the lowest vitality in February and March, while the highest was in September. The area of improved vegetation was much larger than that of degraded ones. The largest regions of improvement were Hechi, Baise, southeast of Nanning and east of Guilin, and the largest regions of degradation were Chongzuo, middle of Baise, west of Nanning and middle of Guilin. Beihai city, the most seriously degraded area, has a 28.9% degrading area. The types of Guangxi's vegetation coverage have changed a lot. Forestry area increased significantly, while agricultural area decreased significantly. Objective: Temperature and precipitation are positively correlated with vegetation cover, the positive correlation is more significant on the monthly scale than that on the annual scale. The effects of precipitation on vegetation were more significant than those of temperature. Human activities reflected by MODIS land cover data indicates that the significant increase in forestry area is the main reason for the increase of Guangxi's NDVI.

Objective: Reticulitermes chinensis (Isoptera:Rhinotermitidae) is a soil/wood-nesting amphibious termite species. It is easy to produce replacement reproductives (RR), which is the main reason for its serious damage and difficult control. In order to provide references on mechanism of reproductive differentiation and the development of control technology of termites, we investigated the characteristics of RR differentiation and the influence factors, including the population composition, quantity, the developmental level and the food consumption of experimental groups during the differentiation process of RR. Method: The colonies of R. chinensis were collected from the field and reared in the laboratory for several days to adapt to the experimental conditions. Then they were separated to different experimental groups with different compositions, populations and developmental levels. We observed the development of RR and the effects of the composition, the population, the developmental level and the food consumption on the durations of RR differentiation, mature RR differentiation and oviposition.Result: The no wing bud replacement reproductives (NRR) of R. chinensis was differentiated through four development stages, namely workers, pre-replacement reproductives, NRR and mature NRR. The short wing bud replacement reproductives (SRR) of R. chinensis was differentiated through three development stages, i.e. short wing bud nymphs, SRR and mature SRR. In the population with nymphs, workers differentiated to RR earlier than nymphs did. When the number of individuals in the population was between 100 and 200, the population quantity, the number of soldiers, and with or without nymphs in the population did not significantly affect the RR differentiation duration, mature RR differentiation duration and oviposition duration (P>0.05). Besides, population maturity had a significant influence on the duration of mature RR differentiation (P < 0.05), while the developmental level of experimental populations had no significant effect on the durations of RR differentiation and oviposition (P>0.05). As the population number was between 100 and 150, there were no significant differences on the durations of RR differentiation, mature RR differentiation and oviposition with or without soldiers (P>0.05). Meanwhile, when the population number was 200, soldiers in populations had a significant effect on the duration of RR differentiation (P < 0.05), but not on the durations of oviposition and mature RR differentiation (P>0.05). The effect of food consumption on the duration of first RR differentiation was the most obviously among all RR differentiation durations. Objective: Workers' ability to develop to RR was slightly stronger than short wing bud nymphs'. In RR differentiation process, the duration of RR differentiation was mainly affected by the population composition and the food consumption, the duration of mature RR differentiation was mainly influenced by the developmental level of test termites, while the population composition, the population number and the developmental level of experimental groups did not significantly affect the oviposition duration. Furthermore, the developmental level had significant or extremely significant effects on the duration of mature RR differentiation (P < 0.05 or P < 0.01). Therefore, more attention should be paid to the mature population dispersal in R. chinensis control.

Objective: SID gene encodes a transmembrane channel protein which participates in the transmembrane transport of RNAi signal such as dsRNA in many organisms. This study aimed to clone the SID-1 gene from Hyphantria cunea larva, and to analyze the gene sequence and expression profiles. Moreover, the gene function involved in systemic RNAi in H. cunea was explored. Method: The cDNA sequence of HcSID-1 gene was cloned from H. cunea larva using RT-PCR and RACE technique, and the putative amino acid sequence was analyzed by bioinformatics method. The temporal and spatial expression levels were detected by qPCR. The interference efficiency of exogenous dsRNA to HcSID-1 was validated by RNAi and qPCR technique. Furthermore, the interference efficiency to other target genes were detected when HcSID-1 expression was interfered simultaneously.Result: A systemic RNA interference defective (SID)gene named HcSID-1 (GenBank accession No.:MG696730)was cloned from H. cunea larva, and was 2 761 bp in length. The gene contained a 2 613 bp open reading frame (ORF), encoding 870 amino acid residues. The predicted molecular weight of the putative protein was 97.08 kD with the isoelectric point (pI)of 6.81. The protein contained a signal peptide which was 19 aa in length. Amino acid sequence analysis showed that the HcSID-1 protein had a long N-terminal with 308 aa, and 11 typical transmembrane domains between 309-855 amino acid residues. Phylogenetic analysis indicated that HcSID-1 had high similarity to SID genes of lepidopteron insects, and had the closest relationship with BmSID-3 of Bombyx mori. Temporal and spatial expression analysis showed that HcSID-1 expressed in all tested developmental stages and larva tissues, with a high expression level in the larva midgut. The expression level of HcSID-1 was able to be significantly decreased by HcSID-1 dsRNA injection in H. cunea larva. Meanwhile, the sensitivity to dsRNA of HcChi gene was reduced with the low expression level of HcSID-1 in H. cunea larva. Objective: A HcSID-1 gene obtained from H. cunea had the typical SID family characteristics. The down-regulation of HcSID-1 could affect RNA interference efficiency to other target genes, suggesting that this gene may have the same function similar to other SID genes in the systematic RNAi process.

Objective: Studying the comprehensive effects of energy conservation, emission reduction and forest conservation on the economic and climate change, especially analyzing the realization path, costs and benefits of the climate targets of "to ensure that the global average temperature is higher than the pre-industrial level within 2℃ and make efforts to control the temperature within 1.5℃" proposed by Paris Agreement, as well as clarifying the important role of forest conservation in mitigating and coping with climate change, will provide a theoretical basis for the integration of forest conservation into climate negotiations, promote low-cost emission reduction, maintain moderate economic growth, as well as improve the ecological environment and the efficiency of climate policies. Method: This paper sets up four scenarios. Depending on the approaches taken to tackle climate change, each scenario (excepting baseline scenario) is subdivided into two categories, i.e., comprehensive abatement and direct abatement. Comprehensive abatement represents an organic combination of energy conservation, emission reduction and forest conservation. On the contrary, direct abatement means that only energy conservation and emission reduction measures are taken, without considering the potential contribution of forest conservation to climate change. Introducing the forest conservation control variables and cost functions into the DICE-2013R model, using the GAMS (general algebraic modeling system)software to program and the PATHNLP solver to solve the model, this paper simulates the comprehensive abatement effects of energy conservation, emission reduction and forest conservation, and compares it with the single direct abatement situation.Result: Firstly, the organic combination of these two approaches, i.e., energy conservation, emission reduction and forest conservation, is conducive to cut down the total cost of tackling climate change (climate change damage and total carbon abatement costs), as well as to alleviate the pressure of substantial carbon abatement to a certain extent by buying time for R&D of carbon abatement technology. Secondly, the combination of these two approaches makes the peak of total carbon emissions decrease and the peak of industrial carbon emissions increase. The latter is slightly higher than the former. Thirdly, the government should rationally design the proportion of direct abatement (i.e., energy conservation and emission reduction) and indirect abatement (forest conservation, which will reduce carbon emissions and increase carbon sinks), so as to minimize the total carbon abatement costs. The moderate combination of energy conservation, emission reduction and forest conservation makes the lowest costs of carbon abatement and the highest social welfare under the optimal case. Fourthly, considering the potential contribution of forest conservation to climate change, the social carbon costs of 2℃ and 1.5℃ targets proposed by Paris Agreement are significantly declined. The difference between social carbon cost and carbon price tends to shrink. Last but not the least, the combination of these two approaches can achieve the virtuous circle of reducing carbon emission, increasing forest carbon sinks and promoting economic development. In comprehensive abatement situation, the efficiency of Paris Agreement is improved and 1.5℃ target transfers from cost inefficiency into cost efficiency, although the net income is limited. Objective: In the new economic normal, industrial production is facing heavy downward pressure. The abilities to save energy consumption and reduce emissions are weakened generally. In this period of structural adjustment in China, the government should introduce more policies to guide public funds and private funds to invest in afforestation and reforestation as well as other forest carbon sinks activities, take full advantages of the"combination boxing" (i.e., strengthen energy conservation and emission reduction, increase forest carbon sinks), so as to achieve the virtuous circle of reducing carbon emission, increasing forest carbon sinks and promoting economic development.

Objective: The aim of this study was to develop stem taper equation for Larix gmelinii in Daxing'anling based on quantile regression models, and the results were used to compare and analyze for fitting and validation of different quantiles (τ=0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9)and quantile groups. Method: Stem taper data of Larix gmelinii were collected from Daxing'anling. NLP method in SAS software was used to fit Max and Burkhart segmented taper equation which was based on quantile regression (Koenker and Bassett, 1978), and the performances of all models were evaluated by use of these evaluation statistics:coefficient of determination (R²), mean absolute bias (MAB), root mean square error (RMSE), mean percentage of bias (MPB), and prediction accuracy (P%).Result: 1) The results showed that Max and Burkhart segmented taper equations could converge based on nine different quantiles (τ=0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9), showing that quantile regression could provide many different quantile estimates, and predict stem profile for different quantiles. 2) The base model was similar to the models with quantile equal to 0.4, 0.5, and 0.6. Comparing with based model, we found that all of different quantile groups (3, 5, 7, 9)could improve the prediction precision. The quantile regression based on three quantiles group (τ=0.3, 0.5, 0.7), five quantiles group (τ=0.3, 0.4, 0.5, 0.6, 0.7), seven quantiles group (τ=0.1, 0.2, 0.4, 0.5, 0.6, 0.8, 0.9)and nine quantiles group (τ=0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9)were better than the others with the same quantile groups. The quantile regression with five quantiles group (τ=0.3, 0.4, 0.5, 0.6, 0.7)were the most accurate in predicting taper equation of Larix gmelinii based on fitting statistics. 3)Model validation showed that statistical criteria of most quantile regression groups were superior to those of the base model and the individual quantile model. Relative to the base model, MPB, MAB and RMSE of five quantile combination (τ=0.3, 0.4, 0.5, 0.6, 0.7)model reduced by 13.9%, 13.9%, 13% respectively. Objective: Quantile regression models could improve the prediction precision. Based on the five quantile group (τ=0.3, 0.4, 0.5, 0.6, 0.7), Max and Burkhart segmented taper equation showed good performances on fitting and validation statistics, and was suitable for predicting stem taper of Larix gmelinii in Daxing'anling.

Objective: The scientific selection of city trees is still an important work in the future.Based on the statistical data of the Municipal Tree Survey of the State Forestry Administration in 2017 and related data, the selection of city-trees in 348 cities above prefecture level in China was summarized, and the characteristics of overall application, species selection and regional distribution, application problems of city-trees were analyzed.In order to provide a basis for tree species selection and greening work in cities in China.The analysis results are as follows, there are 245 selected city-trees in China, accounting for 70.4% of the total number of cities, and 27 cities choose two type of city-trees at the same time; all prefecture-level cities in Hebei, Jiangsu, Zhejiang, Jiangxi, and other provinces, as well as Beijing, Tianjin, and Chongqing, have selected city-trees; from the tree species composition, the city-trees cover 81 species of 29 families and 56 genera, mainly concentrated in Pinaceae. Leguminosae, Rosaceae, Oleaceae, Cypress, and Lauraceae plants, among which Sophora japonica, Cinnamomum camphora, and Ginkgo biloba were selected by 49, 49, and 19 cities, respectively. Ficus is the most commonly used urban tree species in southern cities. From the geographical location, the choice of urban trees in different regions has its own characteristics, while in northern cities, S. japonica, cedrus and ginkgo are selected as the most popular ones. Pinus tabulaeformis, elm and weeping willow are more used as city-trees, C. camphora, C.longepaniculatum, Koelreuteria paniculata and magnolia are more used in the Yangtze River valley, camphor, phoenix wood, almond and osmanthus are more used in the southeastern coastal areas, among which the frequency of using S. japonica as city-tree in North China and Northwest China was 53.3% and 50.0% respectively, and the frequency of using camphor tree in central and Eastern China were 46.2% and 20.3% respectively. In the process of choosing city trees, there are still some problems in many cities, such as the application of city trees is not extensive, the use is unreasonable, and the name is not standardized. It is urgent to improve the greening in cities.

As a new type of lightweight aerogel, the biomass cellulose carbon aerogel has unique isotropic 3D network and hierarchical porous structure. Based on the individual structure, the carbon aerogel owns the excellent properties of aerogel (high specific surface area, high porosity and low density), carbon materials (heat resistance and electrical conductivity) and biomass materials (biodegradable and biocompatible). In recent years, it has becomes one of the hotspot research fields in nano-functional materials. The raw material of biomass cellulose carbon aerogel is widely available, including plants (wood, bamboo, fruits and vegetables), marine life and bacteria. Based on the differences in raw material form, the preparation methods of biomass carbon aerogel are summarized as gel carbonization method and biomass direct carbonization method. In addition, this paper introduces the main properties and modified methods, such as light and more porous, hydrophobic, stability, electrical conductivity, and metal doping and heteroatom doping modification. These excellent material properties make it been widely used in the insulation, electrochemical, adsorption, and many other fields. Also, it is potential to be used more forward-looking emerging material fields, such as drug release, antimicrobial materials, tissue engineering and electromagnetic shielding. The functional preparation, characterization and application of biomass cellulose carbon aerogel are emerging. Based on the research, this paper discusses the prospective of biomass cellulose carbon aerogel. As a new type of green material, the biomass cellulose carbon aerogel provides an application prospect for high-value and functional application of biomass materials.

Objective: This study aims to analyze the input structure of forest farmers' factors, in order to reveal the reasons why the investment in forestry is always targeted at labor-intensive sectors, in order to provide decision-making support to improve farmers' incentives on forestland management and stimulate the transition from labor intensive to capital intensive. Method: Based on the perspective of capital heterogeneities, this paper establishes a theoretical framework on the relationship between labor and capital investment on forestland. Then, a household survey dataset is employed to examine the hypotheses, which covers 9 provinces and is conducted by the National Forestry and Grassland Administration. Since the features of joint interdependence, endogeneity and censoring, this study adopted the modified Nelson-Olson two stage approach to study the relationship between capital and labor input and its influencing factors. The modified technique combines the Nelson-Olson approach and the MV Tobit method, in order to improve the estimation efficiency.Result: The estimation results showed that the coefficients of labor and the whole capital were significantly positive, reflecting the significant complementary relationship between them. However, the relationship is dependent on capital's heterogeneities. In detail, the relationship between labor and yield-incremental capital is significantly complementary, while it is substituted for labor and labor-saving capital. However, the substitution relationship is not significant, which is not in line with the expected path of Hayami-Ruttan's technological change. Further investigations showed that the substitution between labor and labor-saving capital would be weakened by three factors, i.e., the low ratio of labor-saving capital, the unsound social service system in forestry and the varied topography of forestland. This weakness would lead to the dominance of the complementary relationship between yield-incremental capital and labor, which is the main reason of why labor and the total capital are complementary. In addition, the wage in off-farm sector has a negative effect on farmers' investment decision, while the role of timber price is not significant. Objective: There is a complementary relationship between labor and capital investment on forestland, which is opposite to that on farmland. This relationship is mainly caused by the nature of forestland management, and reflects that the findings on farmland cannot be directly used on forestland decisions. This unusual relationship would provide a useful perspective on why forestland investment is not evolved from labor-intensive to capital-intensive. In detail, the complementary relationship between total capital and labor means that forestland investment would be labor-intensive. It cannot be evolved into a capital-intensive along the expected path of Hayami-Ruttan's technological change. These findings are beneficial to improve farmers' incentives on forestland management and stimulate an evolution of factor inputs from labor intensive to capital intensive. Currently, the social service system in agriculture has been emphasized deeply, which is not the case in forestry. Therefore, in the follow-up tenure reform, it is emergent to establish a sound social service system, especially on the development of mechanization in forestry sector.

Objective: This paper tried to clear the income effects of access to forest property rights mortgage loan (FPRM), the participation of poor households and its influencing factors. The conclusion were expected to provide references for improving the FPRM policies targeting poverty alleviation. Method: Based on the survey data of 702 households from 5 province in China, this paper used the treatment effect model to analyze its effect on household agriculture income, then applied the bivariate Probit model to analyze different poor households' loan behaviors with the FPRM and its influencing factors.Result: The impacts of access to FPRM were obviously positive, more sensitive for the general poor, and productive fixed assets had a significant impact on agriculture revenue. The participation of different poor households in loan were weak, and its influencing factors were different, to be specific, in terms of demand for FPRM, families get sick or not had merely significant positive impacts on the severely poor, while, the cognition of the forestry subsidy policy had significant negative impacts on the non-poor, in terms of the availability of FPRM, having families worked in government agency or not and the proportion of breeding revenue had merely significant positive impacts on the non-poor, productive fixed assets had significant positive impacts on the general poor, but negative impacts on the non-poor. Objective: The income effect of FPRM was obvious, but it was not clear the FPRM policies helped the poor to alleviate poverty, the availability of FPRM was at a low level, and the demand of the poor were not high. Therefore, to adapting to the new needs of the strategy of helping the poor to alleviate poverty, extending the function of FPRM and improving its performance, we should create and improve the design of FPRM products and precise assistance modes targeting poverty alleviation, enhance the ability of poor farmers to undertake loans which could raise their loan availability, improve the long-term multiple cooperative operation mechanism of FPRM for poverty alleviation which could extend the function of FPRM policies and promote its performances from all-round.

Objective: Clarifying the short-term response of fine roots to soil water gradient in the P. tomentosa plantation, to have a better understanding of the ecological adaption strategy of its roots to soil moisture and provides theoretical basis for the optimization of its artificial forest moisture management strategy. Method: Three irrigation treatments were set in a two-year-old P. tomentosa stand planted in sandy loam, i.e. full irrigation (FI), controlled irrigation (CI), and control (CK). After 2 months of irrigation, root sampling down to 150 cm depth was conducted in each treatment using the soil core method. Through the measurement of root samples, root growth, distribution and morphology data in each treatment, soil depth and horizontal distance were obtained.Result: Vertically, in each soil layer, there is no significant difference in fine root biomass density (FRBD) among treatments (P>0.05). In the whole root zone and the area with a large difference in moisture in shallow soil layer among treatments, the distribution depth of fine root showed a trend of CK > CI > FI. However, this trend was not obvious in the area with less difference in soil water content. Horizontally, FRBD in the CK decreased gradually with the increase of the distance from trees, but this trend was very weak in FI and CI treatments. There was no significant difference of FRBD among treatments at each horizontal distance (P>0.05), except for the distance of 30 cm from tree, where FRBD of CK was significantly higher than that of FI and CI treatments (P < 0.05). On a two-dimensional scale, fine root distribution tended to be shallower with the increasing distance from tree. Under irrigations, fine roots mainly concentrated in the shallow soil layers at both sides of the dripper, while the majority of fine roots in the CK distributed in the relatively deeper soil layers close to the tree. For each soil layer within 0-50 cm, no significant difference in fine root morphology was found among treatments (P>0.05). Both the variation of the total fine root biomass and length among the treatments followed an order of CK > FI > CI. Objective: In conclusion, when a short-term moisture difference occurred in the shallow soil layers, 1) the fine roots of P. tomentosa distributed deeper and tended to concentrate closer to the tree with the aggravation of drought stress, 2) P. tomentosa preferentially adjusted the fine root distribution rather than the fine root morphology in the shallow soil layer to adapt to soil water stress, 3) as to the total amount of fine roots, P. tomentosa adopted a regulation strategy of slight decrease at first and subsequently distinct increase. High frequency irrigation should be applied to two-year-old P. tomentosa stand in dry season.

Objective: The objective of this paper was to carry out quantitative analysis of the dynamics of spatial point pattern and its associations with different forest type blocks in Liangshui Nature Reserve during the last forty years (1974-2009), which provided some insights for ecological and environmental protection within this region. Method: The datasets were obtained from four different forest resource inventories carried out in 1974, 1989, 1999, and 2009, respectively. The spatial point pattern and its associations with six different types of natural forest, namely Pinus koraiensis (PK), mixed Picea asperata-Abies fabric (PA), mixed Populus davidiana-Betula platyphylla (PB), mixed coniferous (CF), mixed coniferous-broadleaved (CB), and mixed broadleaved (BF), were calculated using the O-ring statistics within Programita (2010 version) software.Result: Results showed that the areas of different forest types changed significantly during the periods from 1974 to 2009, with areas of PK and PA remaining unchanged, while the areas of other lands (e.g., non-forest land, Larix gmelinii plantations and Pinus koraiensis plantations) and PB both decreased significantly, and most of them were converted into the CF, CB and BF. The O-ring statistics indicated that all the six forest types displayed evident pattern of random distribution within different periods (approximately 92.74%), mainly due to harvesting at early period and complex ecological habitats in this region. The spatial associations among the different forest types were predominated by non-correlations (approximately 71.29%), and the percentages decreased significantly with the increases of recovery time, while the percentages of spatial negative association increased significantly with the increases of recovery time, however the percentages of positive spatial association always remained stable, with an average of about 6.56%. The development patterns of spatial associations among 15 different forest types were divided into three categories. CategoryⅠindicated the spatial associations between two alternative type blocks would be converted from early non-correlations at entire scale to the later non-correlations at small scale and positive correlations at large scale (only including PK & PA), while the spatial associations between two alternative type blocks for categoryⅡusually transferred from the early non-correlations to the later negative-correlations or fluctuated between non- and negative-correlations at entire scale, including PK & CB, PK & BF, PA & PB, PA & BF, PB & CB, PB & BF, CF & CB, CF & BF and CB & BF. The spatial associations between two alternative type blocks of category Ⅲ were all non-significant (namely non-correlations) at all scales during the entire periods. This group included 5 pairs:PK & PB, PK & CF, PA & CF, PA & CB, and PB & CF. Objective: The structures of the forest types in this region have been significantly improved during the last 60 years (i.e., stop deforestation in 1952), however the status of the landscape structures within Liangshui Nature Reserve still remains in the recovery phase, the spatial patterns of different forest types distributed randomly for all periods, and the spatial associations of the different forest types within this region are still relatively weak and unstable. Thus, implementing more rigid and effective conservation of the forest resources in this region is still indispensable.

Objective: A Mytilaria laosensis plantation after strip clear-cutting was used to study the temporal and spatial dynamics of seed rain sand submerged seed in the reserved belts (hereinafter referred to as the reserved belts) and the stripclear-cutting sites (hereinafter referred to as the clear cutting sites), in order to provide scientific basis for the harvesting design and natural regeneration of the plantation. Method: After the plantation had been harvested with strip clear-cutting, three fixed plots were respectively set in the reserve belts and the clear-cutting sites, and the seed rain in the fixed plots was surveyed for two consecutive years. Based on the data of the surveys, the composition of the seed rain in different fixed plots was analyzed with the single factor variance analysis and t test. The seed rain densities and submerged seed densities on the strip clear-cutting sites with different distance to the forest edge, were respectively simulated and forecasted with a power function model, exponential function model, logarithm function model that transformed from the power function, and logarithm function that transformed from the exponential function. Results: For the seed rain of the plantation, the starting phase was in late September to October, the peak period was in the middle and late October to December, the fading period was from late December to early January of following year. In the reserve belts, both the seed rain and submerged seed densities had no significant difference in different plots in the same year, and in the same plot in different years. At the clear-cutting sites, both the seed rain and submerged seed densities with few equidistant location away from the forest edge, had a significant difference (P < 0.05) in different plots in the same year, or in the same plot in different years. Percentage of submerged seed with seed rain at the clear-cutting sites, was increasing at first then declining with the increase of distance to the forest edge. Spatial distribution of the seed rain and the submerged seed densities on the clear-cutting land of the reserve belts were approximately exponential distribution, the farthest distance away from their spread was 25 and 20 m respectively. Objective: In the forest plantation which reached the mature age, the seed source was very sufficient for natural regeneration. If harvesting time of the plantation is from December to the end of January of next year, when the seeds have been scattered and are sufficient, the strip clear-cutting with no limit width and clear-cutting could be chosen as the ways of harvesting and regeneration for the plantation, but ways of the strip clear-cutting and clear-cutting should be under the premise of meeting the national policy on artificial forest harvesting. If the harvesting time is from June to September, suitable width and maximum limit width of the strip clear-cutting should be respectively within 35 and 40 m. The logarithmic function model based on exponential function transformation is better to simulate and forecast dynamics of seed rain and submerged seed densities on the clear-cutting sites of the reserve belts with the increasing distance of forest edge.

Objective: In this study, we investigated the distribution regularity of mineral elements in different plant organs and gender differences between male and female plants of Fraxinus velutina, in order to provide a theoretical basis for further elucidating the physiological mechanism of the difference in growth of female and male plants of Fraxinus velutina. Method: The dynamics of mineral element (K, Ca, Na, Mg) contents in different organs of male and female plants of Fraxinus velutina were compared.Result: The result presented in the following four aspects:1) The K content in different organs of Fraxinus velutina was in order of fruit > leaf > branch during the growing season from May to November. However, the order of Ca and Mg in different organs of Fraxinus velutina in each months during the growing season was leaf > branch > fruit. From May to June, the order of Na content in different organs was leaf > fruit > branch, while in the middle and late growing season the order of Na content in different organs was leaf > branch > fruit. During the growing season, the K content in the leaves of Fraxinus velutina decreased with time, the contents of Ca and Na in leaves increased with time, and the Mg content of leaves remained stable. 2) Comparison of mineral elements contents in leaves of male and female plants of Fraxinus velutina showed that, the K, Ca, Na and Mg contents of male plants were higher than those of female plants in each month during the growing season, but this difference was significant only in some months of the growing season. 3) Correlation analysis of mineral elements contents in the same organ of Fraxinus velutina showed that, the leaf K content was significantly negatively correlated with leaf Ca and Mg content respectively, while leaf Ca and leaf Mg contents showed a significantly positive correlation. There was no significant correlation between Na content and other elements contents in leaves. Similar to leaves, there was a significantly negative correlation between fruit K and fruit Ca content, while the fruit Ca and fruit Mg content showed a significantly positive correlation. 4) Correlation analysis of mineral elements in different organs of Fraxinus velutina showed that, there were significant positive correlations between leaf K content and branch K content, leaf Na content and branch Na content of both male and female plants. There were significantly and extremely significant positive correlations between leaf Ca content and fruit Ca content, leaf Mg content and fruit Mg content of female plants respectively. There was a significant positive correlation between Na content in leaves and Na content in branches of both male and female plants. Objective: The result showed that there were differences in the distribution of mineral elements between male and female organs of Fraxinus velutina. In the growing season, the mineral element content in leaves of male plants was mostly higher than that of female plants.The female plants bore a large number of fruits and participated in a large proportion of mineral nutrition distribution, which might be the important factor affecting the mineral element content in leaves. The correlation analysis of different element contents in the same organ showed that there was a significant correlation between K, Ca and Mg contents in either leaves or fruits. The knowledge of the proportion distribution of mineral elements among different organs and the relationship is the premise to clarify the physiological mechanism of gender growth difference, and is also the focus of future research.

Objective: In this study, we investigated the effect of different shading intensitieson leaf color and related physiological indexes of Ulmus pumila 'Jinye' and Koelreuteria paniculata 'Xinye', to explore and compare the physiological mechanism of the color generation of the two yellow leaf plant species. This study aimed at maximizing the garden application and providing the oretical basis for yellow leaf plants to be planted in places where sunlight is insufficient or the light is shaded. Methods: One-year-old U. pumila 'Jinye' and K. paniculata 'Xinye' were subjected to different light intensities, i.e. natural illumination, 20%, 50% and 90% shading conditions, for two months, and leaf color, content of photosyn the ticpigments, photosynthetic fluorescence parameters, leaf reflection spectrum, leaf shape and organic matter contents of the two yellow leaf plants were examined, and the chloroplast ultrastructure was observed at the subcellular level. Results: Under the natural illumination, the leaf color of U. pumila 'Jinye' was golden yellow, and that of K. paniculata'Xinye' wasgreenyellow. With the increasedshading degree, the leaf color of the two plants turned green gradually. The leaf color of U. pumila 'Jinye' turned greenobvious, andits yellow-blue parameter (b^*) value decreased from 70.42 to 47.27 under 90% shading condition. The leaf color of K. paniculata 'Xinye' turned slightly greenish. Under 90% shading condition, the b^* value decreased from 65.69 to 58.34and the leaf color remained yellowgreen compared with the control (full natural illumination) group. With the increase of shading ratio, the chlorophyll contents of the two yellow leaf plants increased significantly, the photosynthetic rate and spectral reflectance decreased, the Chl a/b, specific leaf weight, PSII maximum photochemical efficiency (F_v/F_m), maximum fluorescence (F_m) of the two plants were significantly increased. The spectral reflectance of leaves of the two species decreased under the shade environment, and the red edge parameter indicated the light stressof U. pumila 'Jinye'in natural illumination. The structure of thylakoids of the two species also changed greatly under shading conditions. The number of thylakoids and stacking layers in chloroplasts increased, and the thylakoid in chloroplast changed from curved lamella to parallel stack-like granules. Under different shading conditions, there was no significant change in content of soluble sugarsin U. pumila 'Jinye', the soluble protein content was significantly decreased, the leaf areas were significantly increased, and the leaf length-width ratio did not change significantly. For K. paniculata 'Xinye', there was no significant difference in soluble sugars and soluble protein contents under 20%shadingconditioncompared with the control. The contents of soluble sugars and soluble protein under 90% shading condition were significantly lower than those of the control, and the leaf shapes were not significantly different before and after shading. Objective: The leaves of U. pumila 'Jinye' and K. paniculata 'Xinye' were brighter and yellower in the natural condition, however the two species were inhibited to some extent by light. With shading ratio increased, the photosynthesis rate of the two species decreased, the thylakoids were stacked, and the leaf colors returned green in different degrees. Under 20% shading condition, the growth and leaf color of U. pumila 'Jinye' were less affected, the leaf color remained yellowgreen.The 50% and 90% shading conditions were unfavorable for yellow leaf and photosynthetic product accumulation. The leaf color of K. paniculata 'Xinye' turned green slightly under different shadingratio conditions, and was still in the yellow leaf category, but 90% shading condition had serious influence on its photosynthetic physiology. Therefore, from the perspective of growth and leaf coloration, the natural illumination is the best illumination condition for both of U. pumila 'Jinye' and K. paniculata'Xinye', and they can be planted in a suitable shading environment according to their respective physiological characteristics.

Objective: Through the investigation of the growth traits of a 33-year-old Chinese fir (Cunninghamia lanceolata) provenance trial, the genetic variation and geographical variation patterns of the main growth traits of Chinese fir provenances were studied, the effects of early selection were tested to determine the appropriate age, and to select suitable and excellent provenances for the experimental area. Method: Provenances from the full natural range of Chinese fir planted in Liuzhou, Guangxi in 1981 were studied. DBH and tree height at 5, 6, 8, 12, and 33 years of age were measured for each tree, genetic variation in major growth traits were analyzed among different provenances at different ages. The study analyzed the geographical variation of Chinese fir by using the trend surface technique, determined the age range of early selection by using juvenile-mature correlation and evaluated of long-term selection effect of excellent provenances by cluster analysis.Result: There were significant differences in DBH, plant height and volume among different provenances at different ages (P < 0.01).The heritability of DBH, tree height and volume of Chinese fir at provenance level reached 0.35-0.76, and with the increase of age, the heritability of each trait showed a rising and gradually stabilizing trend. There were obvious geographical variation patterns among the tested provenances, and both the DBH and the tree height growth patterns are two-way gradients. The longitude direction showed an insignificant positive variation, and the latitude direction showed increases followed by decreases, and the variation is larger. The research on early selection of provenance showed that the selection in the 6-12 years can include 69%-74% of the final selection. Screening 42 fast-growing provenances from 199 reference sources, and their DBH, tree height and volume reached 24.04 cm, 15.31 m and 0.31 m³ respectively. Compared with the average diameter of Guangxi native provenance, the average DBH increased by 15.70%, the average tree height increased by 11.13%, the average volume increased by 40.17%, and the average genetic gain reached 10.36%, 8.66% and 31.65%, respectively. Objective: There were significant differences in DBH, plant height and volume of provenances at different ages, and the heritability of main growth traits showed an upward and gradually stable trend. The selection of 6-12 years is more conducive to improving the efficiency of Chinese fir genetic improvement. The 42 excellent provenances selected from the 33-year-old mature Chinese fir forests have a larger increase than the local provenances, and are suitable for promotion in the Guangxi Zhuang Autonomous Region and surrounding areas.

Objective: Soil microorganisms play a critical role in maintaining forest ecosystem structure and function. This study aimed to investigate the structure and diversity of forest soil microbial community during succession, to understand the restoration and driving mechanism of soil bacterial community structure during succession. Method: A total of 60 (20 m×20 m) quadrats, 20 each for three forest types (30-year-, 80-year- and 150-year-old secondary forests of Quercus wutaishanica after clear cutting in Taiyue Mountains), were established in June 2015. Soil samples in the 0-10 cm layers were collected with a 10 cm diameter earth drill. High throughput sequencing of 16S rRNA gene was conducted to examine soil bacterial community composition, structure and diversity during natural restoration after clear cutting.Result: During the natural restoration of Q. wutaishanica forest, the relative abundances of Proteobacteria and Chloroflex gradually increased with the succession process, the relative abundances of Actinobacteria and Acidobacteria decreased gradually, while that of Verrucomicrobia and Planctomycetes did not change significantly. The relative abundance of Bacteroidetes and Firmicutes in 80-year-old forest was significantly lower than that in 30-year-old forest, but there was no significant difference between 150-year-old forest and 80-year-old forest. Principal coordinate analyses (PCoA) based on weighted UniFrac distance showed that there were significant differences in soil bacterial community structure among 30-year-old, 80-year-old, and 150-year-old forests. Bray-Curtis similarity based on OTU level further indicated that the average similarity of bacterial community structure between 30-year-old young growth forest and 150-year-old mature forest was 37.9%, and that between 80-year-old forest and 150-year-old forest was 47.2%. These findings suggested that soil bacterial communities at different succession stages in the natural restoration process after clear cutting showed a recovery trend to the old forest. Bacterial species richness and phylogenetic diversity showed a descending trend during natural recovery process. Species richness and phylogenetic diversity of bacterial communities in 30-year-old secondary forest were higher than those in 150-year-old growth forest, whereas there were no significant differences in soil bacterial diversity between middle-aged forest and old forest. Chao1 index and phylotype richness did not show obvious difference between 30-year-old young growth forest and 80-year-old secondary forest, but decreased significantly in 150-year-old mature forest. Variation partitioning analysis showed that bacterial community structure was significantly correlated with soil carbon and nitrogen content. Soil carbon and nitrogen explained 20.2% and 26.3% of variations on soil bacterial structure, respectively, and the unexplained part was 43.4%. Objective: Soil bacterial community structure changed significantly during the succession of oak secondary forest after clear cutting. The difference of bacterial community structure between 30-year-old secondary forest and 150-year-old secondary forest was obvious, and then the structure in 80-year-old secondary forest become more similar with communities in old growth forest during secondary succession. Bacterial diversity showed descending trend during succession. Bacterial diversity in young forest were higher than those in 80-year-old secondary and old growth forest, and the diversity in 80-year-old secondary forest was more close to the level in old growth forest. These findings suggest that bacterial community structure and diversity may be predictable during the secondary succession.

Objective: This study aimed to determine the status of wildlife in Jianfengling district of Hainan Province, and provide substantial data for biodiversity conservation. Method: From March 2014 to March 2015 and May to November 2015, the diversity of mammals and birds in Jianfengling Nature Reserve and the surrounding forest areas in Hainan was investigated with infrared cameras. Result: In this study, with an intensive survey effort of 14 715 camera days, a total of 5 383 effective and independent photos of animals were taken. Based on the collected data, 15 wild mammals species belonging to 6 orders and 10 families, and 33 wild birds species belonging to 8 orders and 17 families, and 2 domestic animal species were identified. Among the detected wildlife species, 2 are listed as Class Ⅰ state key protected wild animals and 8 as class Ⅱ, in China. There are 1, 3, 3, and 8 species evaluated as Critically Endangered (CR), Endangered (EN), Vulnerable (VU) and Near Threatened (TN) respectively by Red List of China's Vertebrates. The top five detected wildlife species with the highest shooting rate were Atherurus macrourus, Leopoldamys edwardsi, Melogale moschata, Lophura nycthemera, and Sus scrofa. Total of 11 species were new records in Jianfengling Nature Reserve (e.g. Petaurista philippensis, Tamiops maritimus and Monticola gularis, etc). A large number of photos of human activities were recorded by infrared cameras in the reserve, which showed that human inference was serious in this area, thus management should be strengthened. Objective: This survey provides valuable wildlife information on the resources of mammals and birds in Jianfengling district, and preliminarily grasps the community structure, spatial distribution and relative abundance of wild animals in the area. There are still many endangered wildlife and endemic species in Jianfengling district. Human activities have potential impacts on wildlife. Infrared-triggered camera trapping techniques make up for the shortcomings and limitations of traditional survey methods.