Recommended ArticlesNews
Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
[Abstract](0) [HTML](0) [PDF](0)
Abstract:
Objective  The geographic national conditions data was used to quantitatively study the change trend of landscape ecological risk at the county scale.  Method  Based on the geographic and national conditions data supported by the GIS technology and Fragstats 4.2 software, the landscape index were selected and the geo-statistical methods were used to analyzed the dynamic changes of landscape, spatial-temporal changes of landscape ecological risks and human disturbance activities in Susong County from 2015 to 2017.  Result  In the northwest, landscape fragmentation, landscape separation, landscape fractional dimension, the level of landscape diversity and landscape ecological risks were all lower; In the central and southeast, landscape fragmentation, landscape separation, and landscape sub-dimension were higher which shows that the landscape distribution structure was more complicated, and the landscape ecological risk was higher; The low ecological risk areas, lower ecological risk areas, and medium ecological risk areas were decreasing, while the areas of higher ecological risk areas and high ecological risk areas were increasing.  Conclusion  From 2015 to 2017, the degree of landscape ecological risk in Susong County increased, and the ecological risk level was transformed from a lower level to an adjacent higher level. The ecological risk levels of mineral resource areas, fish and rice towns, transportation hub towns, agricultural areas, and mountain tourist areas were arranged in order from high to low. [Ch, 6 fig. 6 tab. 32 ref.]
[Abstract](5) [HTML](2) [PDF](0)
Abstract:
Objective  The objective of this study is to determine the saturation value of optical remote sensing estimation of spruce-fir forest biomass, and to improve the accuracy of remote sensing estimation of biomass.   Method  Taking the spruce-fir forests in Diqing Tibetan Autonomous Prefecture as the research object, the saturation value of the spruce-fir biomass was calculated by curve fitting, Tibetan Autonomous and the regression estimation model and BP neural network model of the spruce-fir biomass were established using the forest management inventory (FMI) data combined with Landsat 8 OLI remote sensing image in the contract period and the statistical value of remote sensing factor reflectance extracted from the randomly selected small class sample data. At the same time, based on the regression model, single level and nested two-level(region+age group)mixed effect models considering regional and age group effects were constructed to estimate the aboveground biomass of spruce-fir forests in the study area.  Result  The biomass saturation value of the spruce-fir forests in Diqing Tibetan Autonomous Prefecture was 233 t·hm−2 by power function fitting. The adjusted determination coefficient of the optimal regression estimation model \begin{document}$R_{\rm{a}}^{2}$\end{document} was 0.606, which was higher than \begin{document}$R_{\rm{a}}^{2}$\end{document} (0.542) of the BP neural network model. The fitting accuracy and independence test indexes of the mixed model of each effect level were better than those of the regression model. The two-level mixed effect model had the best fitting accuracy, while the mixed model with age group effect level had the best independence test index. The mixed effect model significantly reduced the average residual error of regression model and BP neural network model in the low biomass section (＜100 t∙hm−2), especially in the high biomass section (＞233 t∙hm−2).  Conclusion  The mixed effect model has a wider estimation range, which can reduce the impact of low overestimation and high underestimation caused by data saturation, and improve prediction accuracy.[Ch, 3 fig. 12 tab. 28 ref.]
[Abstract](1) [HTML](3) [PDF](0)
Abstract:
Objective  This study is aimed to clarify the three-dimensional green quantity (3DGQ) and the characteristics of forest recreation space (FRS) of landscape-recreational forests at different niches, and reveal the rules of constructing landscape-recreation forests and the existing problems.  Method  On the basis of the community ecology theory, with 13, 14 and 26 sample plots selected from Qianshan Park, Zhuhai Institute of BIT, and Meihua City Park respectively as the subjects, each tree was surveyed using high-resolution remote sensing images before 3DGQ and FRS were calculated to analyze the differences between different location of landscape-recreation forests.  Result  a) Qianshan park, located in the core urban area (CUA), had the lowest 3DGQ density. b) Michelia × alba, Ficus microcarpa, Cinnamomum camphora, Litchi chinensis, Khaya senegalensis, Ficus altissima, Delonix regia and Cinnamomum burmannii displayed high values of 3DGQ. c) The three sites showed different spatial distributions of 3DGQ, and Meihua City Park which was located in the core urban area had relatively even distribution of 3DGQ than the others. d) There was a positive correlation between DBH and 3DGQ, which was related to the crown shapes of trees. e) In terms of the spatial allocation, for Delonix regia, Ceiba speciose, Bombax ceiba and Cinnamomum camphora, superiority was given to FRS, while for Michelia×alba, various spatial allocation strategies were adopted.  Conclusion  a) The 3DGQ density decreases while the distribution of 3DGQ showed a strong central tendency with the location of landscape-recreational forests shifting from the core urban area to the sub-urban area (SUA) and finally to urban fringe area (UFA). b) The correlation coefficient between DBH and 3DGQ is related to the crown shapes of tree species and c) the features of different tree species in the progress of the construction of landscape-recreation forest should be taken into consideration in the allocation of canopy space and recreation space. [Ch, 3 fig. 1 tab. 30 ref.]
[Abstract](6) [HTML](2) [PDF](0)
Abstract:
Objective  This study aims to investigate the regulation of OfNAC genes on flower opening of Osmanthus fragrans.  Method  From the transcriptome data of O. fragrans ‘Yanhonggui’, the related OfNAC g enes were screened and analyzed to predict the physicochemical properties and structure. Real-time fluorescence quantitative PCR was used to analyze the expression characteristics of the flower opening process.  Result  22 OfNAC sequences were screened from transcriptome. Bioinformatics analysis showed that all of the 22 OfNAC transcription factors contained NAM domains, and the amino acid sequence contained 5 conserved subdomains (A−E). The sequence of conservatism ranging from strong to weak was C, A, D, B, and E. The proportion of different structures in the secondary structure from large to small was random coils, α-helices, extended strands, and β-sheets. Subcellular localization and transmembrane structure prediction showed that OfNAC17, OfNAC17-X2, OfNAC53, OfNAC91, OfNTM1-9 was on the membrane, while other OfNAC transcription factors functioned in nucleus. During the O. fragrans flowering process, the relative expression levels of OfNAC100-2, OfNAC43 and OfNAC73 reached the peak at the boll stem stage (S4), and then decreased. The relative expression of OfNAC43 was the highest at the boll stem stage (S4). The relative expression of OfNAC71, OfNAC29-1, and OfNAC21/22 increased slowly from the initial stage (S1), reached the highest at the apical shell stage, and then decreased as a whole. The relative expression of OfNAC29-2 increased sharply at the bead stage (S2) and reached the lowest at the boll stem stage (S4).  Conclusion  It is speculated that OfNAC100-2, OfNAC43, OfNAC73, OfNAC71, OfNAC29-1, OfNAC21/22, OfNAC29-2 may be involved in the regulation of O. fragrans flower opening. [Ch, 6 fig. 3 tab. 33 ref.]
[Abstract](2) [HTML](3) [PDF](0)
Abstract:
Objective  With an investigation of the content and distribution characteristics of the main nutrient elements in the aboveground parts of Acidosasa edulis of different ages located in the southwest of Zhejiang Province, this study is aimed to provide a scientific basis for the management and exploitation of soil nutrients, as well as the rational utilization of Phyllostachys pubescens resources.  Method  Total harvest method was employed to estimate the biomass, and the contents of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), copper (Cu) and zinc (Zn) in plant samples of different ages (1−3 a) in different parts (leaves, branches and culms).  Result  a) In the aboveground parts of A. edulis, the total contents of the nine nutrient elements were as follows: leaf (48.73 g·kg−1), branch (17.61 g·kg−1) and culm (16.30 g·kg−1); whereas the contents of nutrient elements in leaves, branches and culms were as follows: N, K, Ca, Mg, P, Mn, Fe, Zn and Cu in leaf; N, K, Ca, P, Mn, Mg, Fe, Zn and Cu in branch; N, K, P, Ca, Mg, P, Mn, Fe, Zn and Cu in culm. b) The contents of nutrient elements in different parts were affected differently by the bamboo age which means that branches were most affected, culms were the second, and leaves were the least affected. c) The accumulation of the nine kinds of nutrient elements in culms was the highest (687.38 kg •hm−2), followed by that of the leaves (333.01 kg·hm−2), and the branches (166.29 kg·hm−2). d) The accumulation of different nutrient elements in A. edulis is as follows: N, K, Ca, P, Mg, Mn, Fe, Zn and Cu. e) The distribution rate of nutrient elements was different in leaves, branches and culms with the total distribution rate as follows: culm (57.92%), leaf (28.06%) and branch (14.01%).  Conclusion  The accumulation of N is the highest, indicating that A. edulis has strong nitrogen absorption capacity. Thus, extra attention should be paid to the timely supplement of nitrogen fertilizer to ensure a better production. Also, the leaves of A. edulis have high utilization value because of their comprehensive nutrient elements for human health, thus highly exploitable. [Ch, 1 fig. 3 tab. 29 ref.]
[Abstract](16) [HTML](6) [PDF](0)
Abstract:
Objective   The objective is to analyze the relationship between vegetation community and environmental factors in Jingzifeng National Forest Park of Qingyuan County, Zhejiang Province.   Method   Data of 48 quadrats in park were classified and sorted, and the relationship between forest community types, distribution characteristics and environmental factors was analyzed based on these data.   Result   (1)A total of 193 species belonging to 129 genera and 66 families were recorded in 48 plots. The families with abundant plant species were Fagaceae (19 species), Lauraceae (18 species), Theaceae (9 species), Ericaceae (9 species), Rosaceae (9 species), Aquifoliaceae (6 species), Gramineae (6 species), Rubiaceae (6 species), Chloranthaceae (5 species) and Liliaceae (5 species). The dominant species in tree layer included Cunninghamia lanceolata, Schima superba, Pinus taiwanensis, Cyclobalanopsis glauca, Castanopsis eyrei, Machilus thunbergii, Engelhardia fenzelii and Alniphyllum fortunei. The dominant species in shrub layer were Maesa japonica, Sarcandra glabra, Eurya muricata, and Rhododendron simsii. The dominant species in herbaceous layer were Pteridum aquilinum var. latiusculum, Dicranopteris dichotoma, Dryopteris fuscipes, Carex chinensis, Imperata cylindrica, Selaginella moellendorfii and Arthraxon hispidus. (2) TWINSPAN divided the vegetation community into 10 cluster types. (3) The distribution of the 10 clusters in DCA ordination diagram was regular, which reflected a good environmental gradient. (4) CCA ordination results showed that the most important environmental factor affecting the distribution of each cluster was altitude, followed by soil type, soil temperature and slope. The distribution characteristics of the dominant tree species were similar to those of each cluster.   Conclusion   Altitude is the most important environmental factor affecting the distribution of vegetation community in Jinzifeng National Park, and the altitude plays a decisive role in the distribution of mountain vegetation community. [Ch, 4 fig. 4 tab. 22 ref.]
[Abstract](19) [HTML](8) [PDF](0)
Abstract:
Objective  This study is aimed to explore the differences in photosynthetic capacity of different colors’leaves of Pseudosasa japonica, analyze the leaf color variation from a physiological point of view and lay the foundation for the further exploration of the mechanism of leaf color variation.  Method  With the strong bamboo leaves of Pseudosasa japonica(GL), regreened leaves of P. japonica f. akebonosuji(AL), striped leaves of P. japonica f. akebonosuj(SL), including the white part(SA) and the green part(SG), and the leaves of P. japonica f. akebono(VL) selected as the subjects, an investigation was conducted of the photosynthetic pigment content, ChlNDI, PRI, fast fluorescence kinetic parameters and 820 nm relative absorption.  Result   a) The relative content of chlorophyll in leaves was as follows: GL＞SL＞VL＞AL and the change trend of chlorophyll normalized difference index (ChlNDI) and photochemical reflectance index(PRI) in different leaves of Pseudosasa japonica is the same, which is GL＞SG＞VL＞SA＞AL; b) The maximum redox capacity of Photosystem Ⅰ(PSⅠ) of three bamboo species was GL＞VL＞SG＞AL; the regreened leaves and the striped green leaves of P. japonica f. akebonosuji and the P. japonica f. akebono demonstrate chlorophyll fluorescence curve kinetic activity, but the Photosystem Ⅱ(PSⅡ) reaction center had a significantly lower degree of openness than that of the Pseudosasa japonica, and the share of energy used for electron transfer becomes smaller; c) The lack of chlorophyll makes the light energy absorbed by the unit reaction centers increase continuously, probably because it requires more reaction centers to cope with its lower conversion efficiency, however, the maximum photochemical efficiency (Fv/Fm) and the leaf performance index on absorption basis (PIABS) are gradually reduced, possibly due to the fact that the PSII reaction center is reversibly deactivated, able to absorb light energy yet unable to promote electron transfer.  Conclusion  The variation of leaf color will lead to the difference of photosynthetic pigment content in different kinds of Pseudosasa japonica, and then affect the chlorophyll normalization index and photochemical reflectance index characteristic parameters. Chlorophyll deficiency will affect the active reaction center of PSⅡ, causing reversible inactivation. There are fewer reaction centers in the striped leaves of P. japonica f. akebonosuji, but it still demonstrates good PSⅡ activity, chlorophyll level, and maintains good photosynthetic capacity, usually subject to the uniqueness of flowers and features of leaves. [Ch, 8 fig. 2 tab. 31 ref.]
[Abstract](11) [HTML](5) [PDF](1)
Abstract:
Objective  The objective was to establish the Agrobacterium-mediated transformation system of Oryza sativa subsp. indica ‘Zhonghui 161’.  Method  5 groups of glyphosate concentrations (100, 200, 300, 400 and 500 mg·L−1) were used to test the sensitivity of embryogenic callus to glyphosate. The glyphosate-resistant gene (CP4-EPSPS) was introduced into the embryogenic callus of ‘Zhonghui 161’ by Agrobacterium-mediated method. The transformed embryogenic callus was screened for glyphosate resistance on the selective medium containing 300, 350 and 400 mg·L−1 glyphosate. The resistant callus was further differentiated and seeded.  Result  When the concentration of glyphosate was 300−400 mg·L−1, the browning rate of callus was about 50%, showing a good selection effect. The positive rates of callus on 300, 350 and 400 mg·L−1 glyphosate were 40.16%, 61.72% and 84.04%, respectively. The further differentiation rate was 46.43%, and the seedling rate was 32.84%. A total of 67 regenerated plantlets were obtained, and 43 of them were successfully transformed into CP4 gene by PCR detection. The positive rate of regenerated plantlets was 64.18%.  Conclusion  Agrobacterium-mediated transformation system of ‘Zhonghui 161’ was established. [Ch, 5 fig. 20 ref.]
[Abstract](17) [HTML](3) [PDF](0)
Abstract:
Objective  With an analysis conducted of the relationship between the sprouting ability of Cunninghamia lanceolata (Chinese fir) clones and the activity of antioxidant enzymes under the treatment of mechanical injure as well as an elaboration on the sprouting mechanism of C. lanceolata from the metabolic physiology of enzyme activity, this study is aimed to provide theoretical basis for solving the sprouting problem of C. lanceolata clones.  Method  Using the 1-year-old cuttings of Chinese fir Clone Yang 020 as experimental materials, with pot experiment and treatments of topping removal and no topping set at depths of 0, 3 and 6 centimeters, the enzyme activity absorbance test was carried out to measure and analyze the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in different organs, such as branches and leaves, basal phloem and root tip.  Result  (1) With the increase of soil depth, the tillering capacity of seedlings of Chinese fir clones with and without mechanical damage at different soil depths decreased, and treatments of different soil depths could affect the activity of antioxidant enzymes. (2) With the increase of soil depth, SOD activity of branches and leaves of Chinses fir seedlings increased, while CAT activity decreased. (3) The soil depth of 6 centimeters was conducive to pod accumulation of branches and leaves and root tips.  Conclusion  In conclusion, the mechanical damage and treatments of different soil depths had impact on the clonal tillering of Chinese fir. Of the same soil depth, the tillering of Chinese fir with the removal of topping is higher than the one without the removal. Also, the antioxidant enzyme activity of different organs plants was one of the main factors that affect the mechanical damage of C. lanceolata clones and the tillering of treatments of different soil depths. [Ch, 3 fig. 3 tab. 18 ref.]
[Abstract](17) [HTML](5) [PDF](0)
Abstract:
Objective  This study is aimed to investigate the effect of raw biochar and Fe-modified biochar on the soil adsorption of As(Ⅴ).  Method  First, the raw biochar was produced from the branches of Platanus orientalis by means of pyrolysis at 650 ℃ in an oxygen-limited condition, while its Fe-modified biochar (weight ratio of Fe∶biochar=1∶20) was obtained from the impregnation with FeCl3 solutions and re-pyrolysis beofe the physiochemical properties and surface functional groups of two biochars were examined for changes. Then with the employment of a batch equilibration method, an investigation was conducted of the impacts of initial As (Ⅴ) concentration and sorption time on As (Ⅴ) sorption by soils treated with raw and Fe-modified biochars. At last, The characteristics of the sorption isotherms and kinetics were analyzed.  Result  a) The Fe-modified biochar had higher ash content and electrical conductivity, but lower pH, specific surface area and abundance of surface functional groups than those of the raw biochar; b) Langmuir isothermal models could well describe the sorption process of As (Ⅴ) by biochar-amended soils, indicating that the monolayer sorption was the predominant process: with an initial As (Ⅴ) concentration higher than 25 mg·L−1 in the solution, the sorption capacity of the Fe-modified biochar to As (Ⅴ) (up to 0.36 mg·g−1) was greater than that of the raw biochar; c) The kinetic sorption of As (Ⅴ) could be described by the pseudo-second-order kinetics and the sorption process could be divided into two stages from the critical point of reaction at 4th hour, i.e., rapid sorption and slow sorption, respectively; d) The sorption equilibrium was achieved around 24 hours of reaction, and the maximum sorption capacity of the Fe-modified biochar treatment was 11% higher than that of the raw biochar treatment.  Conclusion  Both biochars could enhance the As (Ⅴ) sorption capacity of the soil, and the addition of the Fe-modified biochar was more effective than that of the raw biochar. Therefore, the Fe-modified biochar is recommended in the reduction of the bioavailability of As (Ⅴ) in contaminated soils by enhancing its adsorption capacity. [Ch, 6 fig. 3 tab. 39 ref.]
[Abstract](15) [HTML](2) [PDF](1)
Abstract:
Objective  The purpose of this study is to explore the change law of biomass and biodiversity of Pinus massoniana plantations under natural succession degree and the relationship between them, so as to solve the problems of fertility decline, biodiversity reduction, and biomass decline of P. massoniana forest under the long-term pure forest management mode.  Method  Taking 3 P. massoniana plantations with different degrees of natural succession in Taizi Mountain, Jingshan County, Jingmen City of Hubei Province as the research object, the typical plot method was used to explore the relationship between biomass, biodiversity and stand density.  Result  (1) The biomass of 40-year-old and 50-year-old stands was significantly different from that of 30-year-old stand (P＜0.05), and the average biomass of 40-year-old stand was the highest. (2) The diversity index increased with the succession, but it was different in different succession stages. Among them, Shannon-Wiener index and Simpson index had significant differences among different succession stages(P＜0.05). There was no significant difference in Pielou index between 40-year-old and 50-year-old stands (P＞0.05), but both were different from 30-year-old stands. The changes of functional richness and diversity were consistent with Pielou index. There was no significant difference in functional dispersion between 40-year-old stands and stands of other succession stages (P＞0.05), but significant difference between 30-year-old stands and 50-year-old stands (P＜0.05). There was significant difference in functional evenness among different succession stages (P＜0.05). (3) There was no significant difference in stand density between 40-year-old stand and the stands of other succession stages (P＞0.05), but significant difference between 30-year-old stand and 50-year-old stand (P＜0.05), and the change trend increased with the succession degree. (4) In the best explanation model, the explanatory variables included functional dispersion, Shannon-Wiener index, Simpson index and Pielou index, among which functional dispersion was more effective than other species diversity indexes in explaining biomass changes.  Conclusion  Biodiversity factors can explain the changes of biomass to some degree, and the functional dispersion of functional parameters has the greatest impact on biomass. [Ch, 1 fig. 4 tab. 34 ref.]
[Abstract](21) [HTML](2) [PDF](1)
Abstract:
Object   This study aims to explore the stoichiometric characteristics of different organs of two minimal population plants, Ostrya rehderiana and O. multinervis, and to predict the limiting elements of the growth of the two plants, so as to provide scientific basis and suggestions for forest soil management.   Method   The mass fractions of total nitrogen, total phosphorus and total potassium in roots, branches, leaves and bark of plants as well as the basic physical and chemical properties of soil were determined. SPSS software was used to test the significance of differences and analyze the differences among different organs of the two plants.   Result   The N and K fractions of O. rehderiana in order from large to small were leaf, branch, bark and root, and the P fraction was branch, root, leaf and bark. The N and K fractions of O. multinervis in order from large to small were leaf, branch, root and bark, and the P mass was root, branch, leaf and bark. The mean values of N∶P, N∶K and K∶P in O. rehderiana were 3.18−19.22, 1.60−2.56, and 1.97−11.80, respectively.The mean values of N∶P, N∶K and K∶P in O. multinervis were 3.57−28.43, 1.14−4.59, and 2.77−11.77, respectively. The ecological stoichiometric features of N, P and K among different organs of the two species were similar, and only N in roots and K in leaves and branches of O. multinervis were significantly higher than those in the corresponding organs of O. rehderiana(P＜0.05).   Conclusion   The limiting elements affecting the growth of O. rehderiana are N and P, and the one affecting the growth of O. multinervis is P. Therefore, in woodland soil management, N and P fertilizer should be properly applied to O. rehderiana, while P fertilizer should be properly applied to O. multinervis.[Ch, 2 fig. 1 tab. 33 ref.]
[Abstract](18) [HTML](6) [PDF](3)
Abstract:
Objective  This study aims to explore the species composition, population structure and interspecific association of wild Sinocalycanthus chinensis community, and to supplement the distribution of wild S. chinensis resources in Tiantai County, Zhejiang Province.  Method  On the basis of field survey and previous research data, five 20 m × 20 m sample plots of S. chinensis were established for community investigation.  Result  (1) The community types of S. chinensis were diverse, mainly including deciduous broad-leaved forest, coniferous forest and bamboo forest, with obvious stratification. The dominant species of tree layer were Platycarya strobilacea, Lindera glauca, Botrocarpyum contoversum, Cunninghamia lanceolata, and Phyllostachys edulis. The dominant species of shrub layer were Hydrangea chinensis, S. chinensis, and Boehmeria tricuspis. The dominant species of herb layer were Parathylyperis glandulgera, Viola rossii, and Pilea pumila. (2)The population structure of S. chinensis was “Pyramid” type, with the highest proportion of individuals in grade I, accounting for 56.51%, indicating that the population was in the growth stage. (3) The analysis of interspecific association and correlation of species pairs in tree layer and shrub layer showed that the positive and negative correlation ratios were both greater than 1, and there was no correlation between S. chinensis and most tree species.  Conclusion  The species of S. chinensis community are closely related, and the structure and function of the community tend to be perfect, but S. chinensis may be relatively independent in the community. In view of its negative correlation and competitive relationship with Lindera erythrocarpa, Rubus corchorifolius, Cerasus schneideriana, Platycarya strobilacea and other tree species, it is suggested that in the later stage of S. chinensis field conservation, appropriate artificial selective cutting and tending measures should be taken to create a good growth environment. [Ch, 10 fig. 5 tab. 24 ref.]
[Abstract](17) [HTML](9) [PDF](1)
Abstract:
Objective   Wudalianchi Volcanoes, with its intact inland monogenetic volcanic landform and a complete vegetation succession process, is an ideal place to research matters like vegetation succession and the development of biodiversity system development. With a survey conducted of the species diversity and stability of forest community as well as the relationship between species diversity and stability, this study is an attempt to provide scientific basis for the succession, restoration and sustainable development of forest vegetation in Wudalianchi Volcanoes.   Method   Targeting at four old volcanic forest communities, the study has mainly investigated the quantitative characteristics of community structure, the species diversity of the tree, shrub and herb layer, the age structure of community and the age structure of Tilia amurensis and Quercus mongolica populations.   Result   (1) The number of species in the tree and shrub layer of each mountain forest community was bigger on the north slope than that on the south slope: with only one species with an important value≥1 found on the south slope, the composition species of the whole community showed little complexity. (2) On the north slope, the Margalef index and the Shannon-Wiener index of the tree and herb layer are larger than those of the shrub layer while the Simpson index and the Pielou index of the tree and shrub layer are larger than those of the herb layer yet on the south slope, all species diversity indexes of the herb and tree layer are larger than those of the shrub layer. (3) The age structure of forest community was stable on both north and south slopes, so was the age structure of T. amurensis and Q. mongolica populations, which indicated the stability of the communities. (4) On the north slope, the species diversity of the tree and shrub layer are bigger than that of the south slope, while that of the herb layer is smaller than that of the south slope. Moreover, the species diversity of the communities on the north and south slopes show either extremely significant or significant differences, with a large coefficient of variation.   Conclusion   The community structure of the old volcanic forest in the Wudalianchi Volcanoes was simple and the north slope enjoyed a bigger species diversity and higher community stability when compared with the south slope. [Ch, 6 fig. 4 tab. 31 ref.]
[Abstract](19) [HTML](7) [PDF](0)
Abstract:
Objective  The real-time and accurate forecast of field pests has gradually become an important method of pest forecasting to trap insects by light, and to collect, count and identify insect images by computer. This study aims to explore the method of collecting insects in the sampling plate based on insect image and insect density, so as to improve the collection efficiency and accuracy, and reduce the counting and identification errors caused by the overlapping of insects on the sampling plate.  Method  According to the characteristics of insects’ posture on the sampling plate, an image segmentation method based on global contrast was proposed. Combined with threshold iterative segmentation, the insect area was obtained, the insect proportion was calculated, and the collection of insects was completed by controlling the flip of the sampling plate.  Result  Experiments on the actual images of 5 kinds of pest species showed that compared with the 4 algorithms, namely level set, OTSU, threshold iteration and saliency detection based on histogram contrast(HC), the accuracy and recall rate of this method were improved by more than 10%, and good results were obtained. At the same time, the segmentation speed was 3 times faster than that of the level set, which was basically the same as the threshold and HC algorithm.  Conclusion  Due to its simplicity and high efficiency, the segmentation method based on global contrast has high practical application value in automatic pest detection and reporting. [Ch, 7 fig. 1 tab. 17 ref.]
[Abstract](27) [HTML](13) [PDF](5)
Abstract:
Objective   This paper classifies the forest carbon sink demand space of 28 provincial administrative regions and Shenzhen City in China, and puts forward some suggestions for improving the future forest carbon sink demand space of various regions, so as to provide an objective basis for scientific design of carbon sink policy and targeted development of forest carbon sink demand space.   Method   Taking the above 29 areas as sample units, the input and output data of the industrial industries in 2008−2017 statistical yearbook were collected. The directional distance function model was used to calculate the carbon marginal emission reduction cost of the industrial industries in each region, and the demand space model was used to measure the forest carbon sink demand space of 29 areas in the past 10 years. Then cluster analysis and discriminant analysis were carried out on the obtained demand space data.   Result   There were some regional fluctuations in the marginal carbon emission reduction cost and the spatial data of forest carbon sink demand in each sample area. The Pearson correlation coefficient between marginal carbon emission reduction cost and forest carbon sink demand space was 0.999, showing a significant positive correlation. The clustering results showed that the average marginal carbon emission reduction cost in regions of Category 1, 2 and 3 was 15.9, 11.8 and 5.1 thousand yuan·t−1 respectively. The average spatial value of forest carbon sink demand in Category 1, 2 and 3 was 5 719.1, 3 749.3 and 1 741.5 thousand t·a−1, respectively. Through the final discriminant equation, it was found that the demand spatial data of 2011 and 2014 had the most significant impact on regional classification.   Conclusion   On the whole, the classification results are roughly consistent with the economic development level of the eastern, central and western regions of China. The policy scenario simulation shows that the penalty rate of over emission should be taken as an important entry point for the regions of Category 1 and 2, and the quota distribution mode should be optimized. The 3rd category should be encouraged and guided.[Ch, 6 tab. 16 ref.]
[Abstract](22) [HTML](10) [PDF](1)
Abstract:
Bamboo shoots are traditional forest vegetables in China and also large export agricultural products. Palatability is an important index to reflect the economic value, market potential, and quality of bamboo shoots. However, the basic research on the formation of bamboo shoot palatability and development of upgrading technology are relatively weak, which limits the development and application of bamboo shoot quality improvement technology to a certain extent. This paper reviews the main evaluation indicators for bamboo shoot palatability, summarizes the main research results, and puts forward prospects for future research. Current studies on bamboo shoot palatability mainly focus on the following aspects: the interspecific differences in bamboo shoot palatability, the effects of environmental factors on palatability, and the impact of management measures on palatability. The main conclusions are as follows: Sugar, acids, phenols, fibers and amino acids are the chief indicators for evaluating the palatability of bamboo shoots. The formation of palatability depends not only on genetic factors of bamboo species, but also on climate factors and soil texture. Bamboo shoot palatability can be improved by mulching cultivation, fertilization, regulation and control of stand structure, and selection of appropriate shooting time, but there are obvious differences among species in their effects. Future studies on bamboo shoot palatability should focus on such aspects as constructing comprehensive evaluation indicators and methods, exploring the effects of multi-factor interaction on the palatability, revealing the formation mechanism of palatability from the ecological, physiological, biochemical, and molecular aspects, selecting high-quality shoots with good palatability, high yield and strong ecological adaptability for large-scale cultivation, as well as developing the palatability improvement techniques from selection of cultivation environment, precise supplement of soil nutrients, environmental control of shoot bud germination, and treatment of bamboo shoot organs. [Ch, 66 ref.]
[Abstract](16) [HTML](9) [PDF](0)
Abstract:
Objective  The objective of this study is to explore the rooting mechanism of Catalpa bungei, as well as the morphological characteristics and physiological and biochemical characteristics of cuttings during rooting process.  Method  The cuttings of C. bungei were treated with dissolved GGR-6 to promote rooting, and the enzyme activities, nutrients and rooting inhibitors in different rooting stages were measured.  Result  GGR-6 treatment significantly promoted the rooting of cuttings, and the rooting rate reached 82.04%, higher than that of the control treatment (P＜0.01). During the rooting process, the activities of superoxide dismutase (SOD), peroxidase (POD) and polyphenol oxidase (PPO) increased during the formation of a large number of callus, and the maximum values of SOD and PPO were 623.33×16.67 and 57.44×16.67 nkat·g−1, respectively. POD activity decreased during the formation of adventitious roots, and the three enzymes were positively correlated with the rooting rate. The soluble sugar and C/N ratio in cuttings decreased sharply at the callus stage, only about 40% of the initial value, and reached the maximum at 20 days of cutting. The soluble protein and total nitrogen showed a decreasing trend, and reached the minimum at 25−30 days. Under GGR-6 treatment, the change range of nutrients in cuttings was large, and the maximum values were higher than those of the control. Total nitrogen content was negatively correlated with rooting rate (P＜0.05), while soluble sugar, soluble protein and C/N were significantly positively correlated with rooting rate (P＜0.05). GC-MS analysis identified four rooting related substances, three of which might inhibit rooting and one might promote rooting.  Conclusion  The increase of antioxidant enzyme activities of cuttings can promote the occurrence of adventitious roots of C. bungei. Soluble sugar and soluble protein are the main nutrients of cuttings. Quercetin, linoleic acid and palmitic acid may inhibit the rooting of cuttings and phytosterol may promote the rooting of cuttings. [Ch, 2 fig. 4 tab. 32 ref.]
[Abstract](31) [HTML](8) [PDF](0)
Abstract:
Objective   This study aims to investigate the effects of dissolved oxygen concentration on growth, physiological indexes and root structure of hydroponic Phyllostachys violascens seedlings, and to explore the adaptive mechanism of hydroponic P. violascens seedlings to hypoxia.   Method   The hydroponic P. violascens seedlings were used as materials, and the effects of different dissolved oxygen concentrations (0, 2, 4, 6, 8 mg·L−1) on biomass accumulation, leaf area, root activity, antioxidant enzyme activity, photosynthetic pigment content and root structure were analyzed.   Result   The biomass accumulation, leaf area, root activity, leaf antioxidant enzyme activity and photosynthetic pigment content of hydroponic seedlings significantly increased with the increase of dissolved oxygen concentration(P＜0.05). The activities of SOD, CAT, POD and APX of hydroponic seedling leaves treated with 8 mg·L−1 dissolved oxygen reached the peak, which were 746.13×16.67 nkat·g−1, 63.13×16.67 nkat·g−1·min−1, 59 395.45×16.67 nkat·g−1·min−1 and 407.46×16.67 nkat·g−1·min−1 respectively. Under hydroponic conditions, lysigenous aerenchyma was formed in the roots of hydroponic seedlings, and its percentage of root cross-sectional area significantly increased with the decrease of dissolved oxygen concentration (up to 7.1%), while the number of lysigenous aerenchyma changed in the opposite direction (P＜0.05).   Conclusion   Under hydroponic conditions, the higher the dissolved oxygen concentration is, the better the growth of hydroponic seedlings can be. The oxygen requirement for the growth of hydroponic seedlings is greater than 8 mg·L−1 . Hypoxia can induce the formation of lysigenous aerenchyma in the root of hydroponic seedlings, but it is not enough to make it highly resistant to flooding.[Ch, 5 fig. 50 ref.]
[Abstract](19) [HTML](5) [PDF](0)
Abstract:
Objective  The purpose of this study is to explore the effects of rock wool and its different burying methods on improving soil water retention capacity as well as plant growth under pot culture mode.   Method  Lycopersicone sculentum seedlings were selected as the experimental objects. Three treatments were set up to simulate the plant growth under water stress, including burying block rock wool (BR) under the root, sheet rock wool (FR) around the root and inert nonabsorbent material (ck). The dynamic changes of soil water content at 5 cm below the soil surface, the growth and physiological indicators of L. sculentum were monitored.  Result  Under the condition of equal irrigation, the order of soil volume moisture content from large to small was BR, FR and ck, and the soil volume moisture content of rock wool treatment was significantly higher than that of ck (P＜0.05), indicating that rock wool treatment could improve water retention and water storage capacity of potted soil. During the same growth period, the growth index such as plant height, base diameter, leaf number, maximum leaf area, root length and dry weight of L. sculentum treated with rock wool (BR and FR) were higher than those of ck, but there was no significant difference between two rock wool treatments, except that the root length of BR treatment was significantly higher than that of FR treatment (P＜0.05). The order of the chlorophyll a content, total chlorophyll content and relative water content of L. sculentum leaf from large to small in the same period were BR, FR, and ck, while the contents of malondialdehyde (MDA), proline (Pro) and peroxidase (POD) were in the opposite order, indicating that BR was more beneficial to plant root elongation and capable of alleviating plants damage caused by soil water stress.  Conclusion  Rock wool materials can effectively improve water retention and storage capacity of potted soil, and alleviate adverse effects of water stress on the growth and physiological characteristics of potted plants. Burying block rock wool (BR) under the root is more effective in alleviating water stress and promoting plant root colonization. [Ch, 3 fig. 1 tab. 31 ref.]
[Abstract](23) [HTML](4) [PDF](1)
Abstract:
As climate warming further worsens, the studies of bamboo forest carbon sink have gradually evolved into one of the important branches of carbon sink research field. With the employment of CiteSpace software, a literature review was conducted of researches on bamboo forest carbon sink included in the Web of Science Core Collection for analysis and prospects into the future. The results showed that a) with close attention drawn from more and more researchers, bamboo forest carbon sink research is embracing a rapid development; b) with the close cooperation among authors, substantial progress has been achieved in this field with a collection of research papers published, forming a strong core author group while the core institutions have shown obvious geographical agglomeration with great contributions made to this field; c) the existing studies mainly focus on the discussion of bamboo forest carbon storage, bamboo forest carbon sequestration capacity, management methods, bamboo products carbon storage, and the effects of bamboo forests on the promotion of carbon storage and farmers’ income and it has been concluded that bamboo forests have a high level of carbon storage, the carbon sequestration capacity of bamboo forests is significantly higher than that of other forests, management methods have a significant impact on on the promotion of the carbon sequestration capacity of bamboo forest, bamboo products have great potential for substitution and emission reduction and bamboo forests have the double effect on the promotion of carbon sink and farmers’ income; d) the change of research keywords is a reflection of the efforts to cope with the global climate change and promote the sustainable management of bamboo forests by improving the carbon sequestration capacity. In the future, it is necessary to enhance the influence of bamboo forest carbon sinks and encourage countermeasure researches on practical issues to give full play to the double effect of bamboo forest carbon sinks on the reduction of emissions and the promotion of farmers’ income. [Ch, 2 fig. 2 tab. 39 ref.]
[Abstract](19) [HTML](4) [PDF](1)
Abstract:
Objective  The purpose of this study is to introduce renewable bamboo scrimber with excellent mechanical properties and decorative effect, combined with environment-friendly powdery epoxy resin adhesive, to prepare bamboo scrimber/structural insulated panel, so as to promote the sustainable development of woody structural insulated panel(SIP).  Method  The curing characteristics of powdery epoxy resin adhesive and bonding strength, flexure strength, thermal conductivity as well as hot-water resistance were investigated by differential scanning calorimetry (DSC), mechanical property test and thermal conductivity tester.  Result  (1) The optimal curing condition of powdery epoxy resin adhesive was that the curing reaction began at 84 ℃, curing thoroughly at 116 ℃, and curing completely at 180 ℃. (2) When the amount of glue was 150 g·m−2 and the hot pressing time was 15 min, the tensile bonding strength and flexure strength of the composite reached 0.83 MPa and 19.8 MPa respectively, and the thermal conductivity was 0.054 2 W·m−1·K−1 (25 ℃). After being soaked in hot water at 80 ℃ for 3 h, the bonding strength of the composite still reached 0.15 MPa.  Conclusion  The bamboo scrimber/structural insulated panel composite with excellent comprehensive properties and good hot-water resistance is obtained. [Ch, 6 fig. 2 tab. 21 ref.]
[Abstract](16) [HTML](4) [PDF](0)
Abstract:
Objective  This study attempted to explore the adsorption properties of multi-walled carbon nanotubes (MWCNTs) with different functional groups for cadmium, and to reveal the influence mechanism on the bacterial toxicity of cadmium.  Method  The adsorption abilities of Cd2+ on MWCNTs with different functional groups (hydroxylated, carboxylated, aminated and unmodified) were studied by batch adsorption equilibrium test. The effects of MWCNTs with different functional groups on the toxicity of Cd2+ to Escherichia coli (E. coli) were evaluated by the bacterial toxicity test.  Result  The order of Cd2+ adsorption capacity on the four MWCNTs were carboxylated MWCNTs, hydroxylated MWCNTs, MWCNTs, finally aminated MWCNTs, which was related to the oxygen content. The combined bacterial toxicity of MWCNTs and Cd2+ was lower than that of free Cd2+, and the bacterial survival rate increased from 67% to 81% with the increasing carboxylated MWCNTs concentration (0－200 mg·L−1).  Conclusion  The adsorption of Cd2+ by MWCNTs with different functional groups was positively correlated with their oxygen content. The combined bacterial toxicity of MWCNTs and Cd2+ was lower than that of free Cd2+, and it was concluded that MWCNTs could reduce the bacterial toxicity of free Cd2+. [Ch, 4 fig. 2 tab. 26 ref.]
[Abstract](23) [HTML](5) [PDF](0)
Abstract:
Objective  This study aims to explore the effects of thinning and stand types on forest litter stock and soil water-holding capacity, and to provide scientific basis for evaluating water conservation function of different forest stands.  Method  Two forest types (Cunninghamia lanceolata forest and broad-leaved forest) and two types of thinning (thinning C. lanceolata forest and thinning broad-leaved forest) in three small river basins in Jiande City, Zhejiang Province were taken as the research objects. Litter and soil (0−10, 10−30, 30−60 cm) were collected in the field, and the water immersion method was used to analyze the influence of thinning on the forest litter stock and water-holding capacity of different forest stands. Three standard plots (20 m×20 m) were selected in each forest stand for litter collection and soil sampling. The litter stock, water-holding capacity and water absorption rate, as well as the soil bulk density, porosity and water-holding capacity were determined. The statistic data of litter and soil characteristics were analyzed using one-way ANOVA and Duncan.  Result  The litter stock of thinning C. lanceolata forest decreased by 25.2% (P＜0.05), while the maximum water-holding rate and effective retention rate of litter increased by 24.4% and 47.1%, respectively (P＜0.05). Thinning had no significant effect on litter stock in broad-leaved forests, but the maximum water-holding capacity and effective retention capacity of litter increased by 42.5% and 42.2% (P＜0.05) respectively, compared with those without thinning. The overall water-holding capacity of litter in thinning forest was higher than that in normal forest. Thinning significantly increased non-capillary pores porosity and water-holding capacity of non-capillary pores in 10−60 cm soil layer of C. lanceolata forest (P＜0.05). Thinning significantly increased soil non-capillary pores porosity and non-capillary water-holding capacity in 30−60 cm soil layer, as well as those in 0−10 and 30−60 cm soil layer of broad-leaved forest (P＜0.05). The maximal water-holding capacity of each soil layer in the thinning C. lanceolata forest was significantly higher than that in the thinning broad-leaved forest, and the maximal water-holding capacity of 0−60 cm (3 775.19 t·hm−2) of the thinning C. lanceolata forest was higher than that of other forest stands.  Conclusion  Thinning significantly improves the water-holding capacity of forest litter and soil, and the water conservation function of litter and soil in the thinning C. lanceolata forest is the strongest among the four treatments for two stands. [Ch, 3 fig. 5 tab. 24 ref.]
[Abstract](84) [PDF](0)
Abstract:
Objective   The objective of this study is to screen the stable expression of internal reference genes of Melanotus cribricollis larvae infected by Metarhizium pingshaense, so as to lay a foundation for the research on related gene expression in this bamboo wireworm.   Method   Based on the transcriptome data of M. cribricollis larvae, the correlation (R2) and amplification efficiency were analyzed by qRT-PCR with specific primers. The 6 candidate reference genes including β-actin, GAPDH, α-tubulin, RPL13α, RPS3 and RPS27a were evaluated by GeNorm, NormFinder and BestKeeper softwares. The stabilities of selected candidate reference genes including PRS27a and RPS3 were further validated by analyzing the expression of 6 target genes.   Result   GeNorm analysis showed that the expression of PRS27a and RPS3 were the most stable, followed by α-tubulin, RPL13α, β-actin and GAPDH. The most suitable number of internal reference genes was 2. NormFinder analysis showed that the expression of RPL13α was the most stable, followed by α-tubulin, RPS3, RPS27a, β-actin, and GAPDH. BestKeeper analysis showed that the P values of β-actin and GAPDH were ＞ 0.5, which were not suitable for reference genes under the condition of this experiment. There were some differences in the ranking of candidate internal parameters obtained by different software analysis. Comprehensive analysis and expression stability verification showed that PRS27a or RPS3 were the best internal reference genes, and the expression levels of 6 target genes were basically the same.   Conclusion   PRS27a and RPS3 are the most appropriate reference genes for qRT-PCR analysis in bamboo wireworm infected by M. pingshaense. [Ch, 3 fig. 3 tab. 27 ref.]
[Abstract](25) [HTML](8) [PDF](2)
Abstract:
Objective  To determine the effects of subcomponents of algae dissolved organic matter (DOM) on mercury methylation at different decomposition intervals and different Hg2+ concentrations.  Method  Six subcomponents of the DOM derived from the algae through a tandem connection of resin, and then conducted simulation experiments separately.  Result  Algae DOM was mainly composed of hydroxyl group, alkyl group and C＝C of aromatic hydrocarbon, etc. Different subcomponents of DOM before decomposition, the influence of hydrophobic component on mercury methylation was significantly stronger than that of hydrophilic component. With the progress of algal decomposition, the relative content of functional groups was gradually decreasing while the influence of hydrophobic components on Hg methylation first weakened and then enhanced during the decomposition process and hydrophilic component can inhibit Hg methylation.  Conclusion  The increase in relative content of DOM results in the inhibition of Hg methylation. After the decomposition of DOM, the Hg2+ released got methylated by bacteria again, which helped promote the degree of methylation. [Ch, 3 fig. 24 ref.]
[Abstract](19) [HTML](6) [PDF](1)
Abstract:
Objective  This study aims to reveal the effects of human interference on species diversity and biomass in E. grandis plantations.  Method  12 sample plots of E. grandis plantations (20 m× 20 m) with different interference intensities were set up by typical plot method in Cangping Mountain Park in Ya’an City of Sichuan Province, to investigate the species composition, species diversity(richness index D, Shannon-Wiener index H, Simpson dominance index H', Pielou evenness index Jsw), and plant layer biomass.  Result  There were 87 species of vascular plants belonging to 55 families and 82 genera. The number of species in E. grandis plantation decreased with increasing interference. The D, H and H' indices of tree layer and herb layer decreased with the increase of interference intensity. The D, H and H' indices of shrub layer reached the maximum under moderate disturbance. The difference of D and H indices in tree layer was significant (P＜0.05). With the increase of disturbance intensity, the biomass of each plant layer showed different changing trends. The tree layer had the highest volume (12.01 m3·hm−2) under moderate disturbance, while the biomass of shrub layer (394.533 kg·m−2) and herb layer (104.079 kg·m−2) was the highest under light disturbance. The D index of tree layer and H' index of herb layer were significantly positively correlated with aboveground biomass and total biomass of herb layer (P＜0.05). The Jsw index of herb layer was significantly positively correlated with total biomass of herb layer (P＜0.05).  Conclusion  Moderate disturbance will increase species diversity and biomass in E. grandis plantation. The relationship between species diversity and biomass is subject to human interference and natural conditions, and there is no fixed relationship. [Ch, 2 fig. 3 tab. 25 ref.]
[Abstract](20) [HTML](5) [PDF](2)
Abstract:
Objective  With an analysis conducted of the service capacity of urban parks in the main urban area of Fuzhou, this study is aimed to optimize the layout of urban parks, which is reflective of the construction of urban human settlements.  Method  Firstly, using the GIS spatial statistical method, the current status of urban parks was analyzed with the two indicators of recreational accessibility and disaster avoidance coverage employed. Then the city service pressure was calculated before an analysis was made of the potential service demand of city parks by means of city POI (point of interest) data.  Result  1) The current service capacity of Taijiang District and Gulou District is good, as is shown in the large disaster avoidance coverage a well-built transport network and the easy access with Gulouqian Park demonstrating the best service ability; 2) The current service ability of Jinan District and Cangshan District is poor, shown in the small disaster avoidance coverage, the inadequate transport network and the poor accessibility with Feifengshan Park demonstrating the worst service capacity; 3) In terms of potential demand for urban parks, with the urban parks mainly distributed in Gulou District and Cangshan District, Gulou District has the highest service pressure while Cangshan District has the least service pressure.  Conclusion  In conclusion, the layout of city parks is generally favorable with a distribution featured with spacial aggregation: the city parks with a good layout are mainly distributed in the north of Gulou District and the south of Taijiang District while the ones with poor layout rationality are mainly distributed in the southern and southeastern regions of Cangshan District as well as the eastern and northern regions of Jin’an District. The lack of parkland, small avoidance coverage and poor access in such areas are the main reasons behind the low rationality. As a result, it is of vital importance to optimize the urban spatial layout of the 12 optimized urban parks: 4 are located in Taijiang District, 3 are located in Gulou District, 2 are located in Jin’an District with the rest 3 in Cangshan District. On the other hand, with the current land use circumstances taken into consideration, potential urban parks should be built: 45 in Cangshan District, 7 in Gulou District, and 19 in Jin’an District. [Ch, 10 fig. 3 tab. 25 ref.]
[Abstract](26) [HTML](9) [PDF](5)
Abstract:
Objective  This study aims to analyze the sequence characteristics and expression changes of hexokinase family members of Osmanthus fragrans.  Method  Based on the transcriptome data of O. fragrans cultivars ‘Yanhong Gui’, ‘Yulinglong’ and ‘Jinqiu Gui’, HXK homologous genes were selected for sequence analysis and phylogenetic tree analysis, and real-time fluorescence quantitative PCR was used to detect the expression of OfHXKs genes in different tissues and development stages of O. fragrans.  Result  In this study, four HXK homologous genes OfHXK1−OfHXK4 were screened, and sequence identity of OfHXK1, OfHXK3 and OfHXK4 from different cultivars is more than 99%. OfHXKs encode 461−510 amino acid residues, including two conserved phosphorylation motifs phosphate 1 and phosphate 2, and one sugar binding motif. Sequence analysis and phylogenetic tree analysis showed that OfHXK1 and OfHXK2 have N-terminal membrane anchoring structures, which are grouped together with AtHXK1 and AtHXK2 from Arabidopsis thaliana. OfHXK3 without transmembrane region is closely related to AtHXK3, so it was speculated that OfHXK3 has catalytic effect but without sugar signaling function. OfHXK4 protein with 11 amino acid insertions at the adenosine binding domain, is closely related to AtHKL1 and AtHKL2. Four HXK gene members from O. fragrans are all expressed in the annual stem, biennial stem, tender leaves, mature leaves and inflorescence. With the development of flower, the expression levels of OfHXK1, OfHXK3 and OfHXK4 genes increase first and then decrease, while the expression patterns of OfHXK2 genes during flower development are different in the three cultivars.  Conclusion  According to sequence analysis and evolutionary tree analysis, it is speculated that OfHXK1−OfHXK4 all have the function of catalysing hexose phosphorylation, and OfHXK1 and OfHXK2 have the function of sugar sensing and signaling. The expression patterns of OfHXK1, OfHXK3, and OfHXK4 genes during the inflorescence development of the three varieties showed a regular increase and decrease with the process of flower opening, which may be associated with their functions in sugar metabolism. [Ch, 6 fig. 4 tab. 30 ref.]
[Abstract](34) [HTML](14) [PDF](1)
Abstract:
Objective  This study aims to investigate the status of heavy metal pollution in soil and rice safety in Jiaxing, the main paddy field of Oryza sativa in Hangjiahu plain.  Method  In 2018, Jiaxing City was selected as the main rice producing area for investigation and analysis. Soil and rice were sampled during rice harvest period to determine the contents of four heavy metal elements (Cd, Pb, Cr, and As) in soil and rice samples. The pollution level and risk of heavy metals in paddy soil were evaluated by single factor pollution index method, Nemero comprehensive pollution index method, potential ecological risk index method and ecological risk early warning index method.  Result  Contents of Cd, Pb, Cr, and As in soil were 0.01−1.92, 17.60−34.80, 47.00−123.00 and 3.97−9.89 mg·kg−1, with an average of 0.36, 25.78, 72.73, and 7.55 mg·kg−1 respectively. The proportion of soil samples whose Cd content exceeded the soil safety threshold for rice production (Safety Threshold Values of Cadmium, Lead, Chromium, Mercury and Arsenic in Soil For Rice Production, GB/T 36869-2018) reached 31.82%. The potential ecological risks of the four heavy metals from strong to weak were Cd, As, Pb, and Cr, and the region as a whole presented slight potential ecological risks. Cd content in rice grain was safe according to the national criterion, although Cd content exceeded the national standard (GB/T 36869−2018) in some soil.  Conclusion  All indexes of rice in the study area are in line with National Food Safety Standard Limits of Contaminants in Food (GB 2762−2017) and the soil is generally at a safe level for rice production. In the future it’s necessary to monitor changes of heavy metals in soil, especially transformation and availability of Cd, in order to guarantee safe rice production. [Ch, 1 fig. 8 tab. 29 ref.]
2021, 38(1): 1-9.   doi: 10.11833/j.issn.2095-0756.20200283
[Abstract](202) [HTML](30) [PDF](31)
Abstract:
Objective  The purpose is to investigate the content and profile distribution of soil PhytOC in northern subtropical Quercus acutissima forest, and discuss the difference of PhytOC sequestration in Q. acutissima forest at different ages.  Method  Taking soil samples from Q. acutissima forest of different ages in Jurong City, Jiangsu Province as the research object, the soil samples were collected in layers of 0−10, 10−20, 20−40 and 40−60 cm to determine the content of phytolith, PhytOC, and the PhytOC sequestration in soil of Q. acutissima forest.  Result  The available silicon content of soil ranged from 45.74 to 153.32 mg·kg−1, which increased with the increase of soil depth. There was no significant difference in the content of soil available silicon among different layers, but there existed significant difference in soil available silicon content among different forest ages (P＜0.05). The content of soil phytolith, PhytoOC and organic carbon in phytolith in young forest and mature forest increased first and then decreased with the increase of soil depth, whereas that in half-mature forest decreased with the increase of soil depth. The content of organic carbon in soil phytoliths, PhytoOC and phytoliths was significantly different among different forest ages (P＜0.05), but difference was not significant among layers. In addition, the ratio of PhytOC/TOC ranged from 0.36% to 1.49%, which increased with the increase of soil depth. There was no significant difference in the ratio of phytoc/TOC among different soil layers, but there was significant difference among different forest ages (P＜0.05). There was an extremely significant positive correlation between soil phytolith content and PhytOC content (P＜0.01), but there was no correlation between PhytOC content and available silicon content. The PhytOC sequestrations in the soil of Q. acutissima forest ranged from 1.15 to 1.47 t·hm−2, and the proportions of PhytOC sequestrations to organic carbon storage in young forest, middle-aged forest and mature forest soil accounted for 0.80%−1.50%, 0.73%−1.10% and 0.36%−0.67%, respectively.  Conclusion  Affected by soil physical and chemical properties, and leaching, etc., the distribution of phytolith and PhytOC in soil profiles of Q. acutissima forest at different ages is different to some extent. The proportion of PhytOC sequestration to organic carbon storage was small, but it increased with the increase of soil depth, indicating that PhytOC is more stable than other forms of carbon. In terms of time scale, PhytOC sink is an important component of long-term carbon sinks in forests. [Ch, 3 fig. 4 tab. 41 ref.]
2021, 38(1): 10-20.   doi: 10.11833/j.issn.2095-0756.20200260
[Abstract](94) [HTML](70) [PDF](21)
Abstract:
Objective  This study aims to investigate soil moisture variation of different vegetation types during the growing season in the loess region of western Shanxi Province, where the eco-environment is fragile and soil moisture is an important factor restricting the vegetation restoration.  Method  The soil moisture content of 0−400 cm soil layer in the growing season (May to October) in artificial forestland (Robinia pseudoacacia), natural forestland (Acer buergerianum) and grassland (Artemisia lavandulaefolia) was monitored by location observation method. On this basis, the soil active layer was divided according to the standard deviation of moisture content, and the annual soil water storage profit and loss were explored by comparing the water storage before and after the growing season. The soil properties of typical sample plots were measured, and the redundancy analysis of the factors affecting soil water storage capacity was carried out in combination with topography and characteristics of drought and flood in different hydrological years.  Result  (1) The soil moisture of the artificial forestland, the natural forestland, and the grassland ranged from 8.36% to 9.63%, 10.01% to 3.19% and 15.43% to 19.17%, respectively, and the surface soil moisture content of the grassland was significantly higher than that of the forestlands (P＜0.05). (2) The depth of soil water active layer in the natural forestland reached 180 cm, deeper than that of the artificial forestland and the grassland. The soil water active layer was the deepest in moderate humid years, shallower in severe drought years, and the shallowest in normal years. (3) In severe drought years, the depth of soil water deficit of the three types was 100−300, 0−200 and 0−100 cm, respectively. The input and output of soil moisture could keep balance in normal years. In moderate humid years, the moisture content in 0−200 cm soil layer was replenished to different degrees, while the moisture content in 200−400 cm soil layer was close to 0. (4) The soil moisture storage of different soil layers was affected by different environmental factors among which vegetation types and bulk density were the dominant factors of soil moisture in 0−100 cm soil layer, and the water content of 100−200 cm soil layer was mainly controlled by bulk density and slope aspect, while the degree of drought and flood in different hydrological years, the content of soil clay and silt were the dominant factors of soil moisture in 200−400 cm soil layer.  Conclusion  The soil water deficit is severe in drought years, and is alleviated in normal or wet years. Vegetation types have the greatest impact on soil moisture storage. In the future restoration of vegetation in the Loess Plateau, we should not only consider the drought tolerance of tree species, but also the impact of topography, soil properties, and precipitation distribution during the growing season. [Ch, 5 fig. 5 tab. 33 ref.]
2021, 38(1): 21-30.   doi: 10.11833/j.issn.2095-0756.20200139
[Abstract](128) [HTML](62) [PDF](12)
Abstract:
Objective  The purpose of this study is to explore the effects of different proportions of fungus residue and chemical fertilizer on soil enzyme activities during the rice growth period over a long-term scale.  Method  A long-term location experiment in paddy field was carried out in which the fertilizer levels were set as 0% (C0), 50% (C50) and 100% (C100) of conventional fertilization amount, and the relative amount of edible fungus residue was set as 0% (F0), 50% (F50) and 100% (F100), respectively. There were 9 treatments in total. The changes of catalase, sucrase and urease activities in different treatments at the main growth stages of rice and the interaction effect of fungus residue and chemical fertilizer on soil enzyme activities were analyzed.  Result  The soil enzyme activities showed obvious regularity with the change of rice growth period. The catalase, sucrase, and urease activities were 3.01−10.20 mL·g−1, 0.20−2.04 mg·g−1, and 0.54−4.80 mg·g−1 respectively. There were significant differences (P＜0.05) in soil catalase, sucrase and urease among the treatments in different growth stages of rice. The results showed that the combined application of fungus residue and chemical fertilizer promoted the soil urease activity in the early stage of rice transplanting, and enhanced the activities of catalase and sucrase in the filling stage and harvest stage. The activities of catalase and urease were the highest in C100F50 treatment, while the sucrase activity was the highest in C50F100 treatment. Path analysis showed that available phosphorus, alkali hydrolyzed nitrogen and total nitrogen had the greatest impact on catalase, sucrase and urease respectively, with path coefficients of 0.69, 1.80, 0.69 respectively. The combined application of fungus residue and chemical fertilizer promoted soil enzyme activity mainly by increasing the mass fraction of alkali hydrolyzed nitrogen. Interaction analysis showed that the effect of combined application of fungus residue and chemical fertilizer was higher than that of chemical fertilizer and fungal residue alone, and the activities of catalase, sucrase and urease in soil were significantly affected (P＜0.05).  Conclusion  The combined application of fungus residue and chemical fertilizer can significantly increase the activities of soil catalase, sucrase and urease, but with the increase of application amount, the activity of soil catalase, sucrase and urease increases first and then decreases. C100F50 treatment is the optimal choice to improve soil enzyme activity and promote carbon and nitrogen cycle under the experimental condition. [Ch, 1 fig. 4 tab. 38 ref.]
2021, 38(1): 31-37.   doi: 10.11833/j.issn.2095-0756.20200262
[Abstract](52) [HTML](15) [PDF](12)
Abstract:
Objective  This study aims to explore the changes of heavy metal content and soil microbial activity in plantations after 2 years of mixed composting of municipal sludge and garden waste, in order to provide basis for utilization of municipal sludge products in forestry.  Method  A randomized block design was carried out in an experimental Ulmus pumila plantation. According to the sludge content in the compost, four levels of mixed compost (0, 15, 30 and 60 t·hm−2 of composted sludge) were set. After two years of application, soil samples were collected for analysis of six heavy metals(Cr, Pb, Cu, Zn, Cd, Ni), as well as seven soil microbial indicators, including microbial carbon and nitrogen, soil respiration and four enzyme activities. The effects of different fertilization rates on soil quality were analyzed.  Result  After 2 years of sludge composting, the total amount of six kinds of heavy metals increased, but there was no significant difference between different application amounts, indicating that the application of mixed compost had low risk of heavy mental pollution. Soil enzymes, microbial carbon and nitrogen had no obvious change with increment of compost amount, but the soil enzyme index and soil respiration intensity of the fertilized plot were greater than those of the control plot, suggesting that the mixed compost improved soil microbial activity.  Conclusion  When the amount of sludge compost is lower than 30 t·hm−2, the elm forest ecosystem could withstand the increased risk of heavy metals, increase soil microbial activity and improve soil quality. [Ch, 1 fig. 4 tab. 22 ref.]
2021, 38(1): 38-46.   doi: 10.11833/j.issn.2095-0756.20200219
[Abstract](156) [HTML](84) [PDF](9)
Abstract:
2021, 38(1): 47-57.   doi: 10.11833/j.issn.2095-0756.20200267
[Abstract](56) [HTML](10) [PDF](20)
Abstract:
Objective  The objective of this study is to explore the relationship between spatial structure and terrain factors of evergreen broad-leaved forest in Mount Tianmu, so as to provide scientific reference for the management of evergreen broad-leaved forest.  Method  Taking the evergreen broad-leaved forest in Mount Tianmu National Nature Reserve of Zhejiang Province as the research object, a large sample of 100 m×100 m was set up and divided into 100 grids of 10 m×10 m investigation units using the method of adjacent grid survey. The trees in the sample plot were measured. The aggregation index, competition index and mingling degree of tree species diversity were used to describe the spatial structure characteristics. Slope, aspect, altitude and roughness were used as terrain factors. The relationship between spatial structure and terrain factors was analyzed by analysis of variance.  Result  (1) If the slope was too large or too small, the competition index increased significantly (P＜0.05). The mingling degree of tree species diversity on the semi-sunny slope was significantly higher than that on the sunny slope (P＜0.05), and that in class Ⅰ roughness was significantly lower than that in class Ⅲ roughness (P＜0.05). With the increase of the altitude in the plot, the mingling degree of tree species diversity increased significantly (P＜0.05), but the aggregation index decreased significantly (P＜0.05) when the altitude was too high or too low. (2) In roughness of class Ⅲ, the competition index of classⅠslope was significantly higher than that of classⅡand class Ⅲ (P＜0.05), the mingling degree of tree species diversity of classⅡslope was significantly higher than that of classⅠand class Ⅲ (P＜0.05), and the aggregation index and the mingling degree of tree species diversity on the semi-sunny slope was significantly higher than those on the sunny slope (P＜0.05). In the high altitude area of the plot, the competition index of classⅠslope was higher than that of class Ⅱ and class Ⅲ slope (P＜0.05), while in the middle altitude area of the plot, the aggregation index and the mingling degree of tree species diversity of class Ⅲ roughness were significantly higher than those of class Ⅰ and class Ⅱ roughness (P＜0.05).  Conclusion  In evergreen broad-leaved forest community, different terrain factors have different effects on its spatial structure. It is an important management strategy to regulate the spatial structure of evergreen broad-leaved forest under certain terrain conditions. [Ch, 10 fig. 2 tab. 31 ref.]
2021, 38(1): 58-64.   doi: 10.11833/j.issn.2095-0756.20200261
[Abstract](49) [HTML](42) [PDF](10)
Abstract:
Objective  The objective is to analyze the spatial structure of typical secondary forests on shady slope of Luyashan National Nature Reserve, and provide reference for scientific management of natural secondary forest and artificial forest in similar habitats.  Method  Based on the survey data of Larix principis-rupprechtii-Picea spp. secondary forest communities at five different altitudes on the shady slope of Luyashan National Nature Reserve, the spatial structures of the communities at different altitudes were analyzed by calculating the angle scale, size ratio, mingling degree and forest spatial structure index.  Result  The average angular scale was 0.51−0.53. The spatial distribution pattern of the forests was dominated by aggregation distributions, but the degree of aggregation was low. The dominant tree species were randomly distributed in the stand. The size differentiation degree of the trees at all altitudes was close to the mean state, and the size differentiation degree of L. principis-rupprechtii was smaller than that of Picea spp., indicating that L. principis-rupprechtii was more competitive. With the increase of altitude, the spatial isolation degree and the spatial structure index decreased. The overall structure of lower altitude stand was better than that of other altitudes.  Conclusion  The communities of L. principis-rupprechtii-Picea spp. secondary forests in the study area are in late state of succession. The stand at 1 950 m above sea level has the best spatial structure and stability. [Ch, 1 fig. 4 tab. 20 ref.]
2021, 38(1): 65-73.   doi: 10.11833/j.issn.2095-0756.20200209
[Abstract](46) [HTML](30) [PDF](4)
Abstract:
Objective  This study, with an examination of the twig and leaf traits of Michelia wilsonii at different developmental stages, is aimed to research the balanced utilization of such resources so as to better predict the spatial distribution of the branch and leaf traits.  Method  With the M. wilsonii of Zhougong Mountain in Ya’an selected as the research object, the standardized major axis regression (SMA), principal component analysis (PCA) and geostatistical methods were employed to study the correlation and spatial characteristics of twig and leaf traits at different developmental stages.  Result  (1) The fresh leaf weight, dry leaf weight, dry matter content, leaf area, specific leaf area, leaf thickness, annual twig density, biennial twig density and biennial twig dry matter content were significantly different among developmental stages (P＜0.05), while the annual twig dry matter content was not significantly different among developmental stages (P＞0.05); (2) There was a significant correlation between leaf traits among developmental stages (P＜0.05) and a significant correlation between twig traits (P＜0.05) while the correlation among leaf and twig traits was weak(P＞0.05); (3) The optimal model of the semi-variogram function was linear model for the twig and leaf traits among the whole population, with a distribution of randomness while the big tree stage, with a distribution of aggregation, mainly followed the exponential and spherical model; the spatial correlation of small and medium tree stage is weak.  Conclusion  As developmental stages advance, the yielding of profits by M. wilsonii slows down and the distribution of twig and the employment of the semivariance function can help predict leaf traits. [Ch, 2 fig.7 tab. 30 ref.]
2021, 38(1): 74-83.   doi: 10.11833/j.issn.2095-0756.20200199
[Abstract](51) [HTML](24) [PDF](8)
Abstract:
Objective  To study the effect of different light and nitrogen application on the clonal propagation characteristics and biomass distribution of Dicranopteris dichotoma, aiming to provide a theoretical basis for the development of monolayers of D. dichotoma.  Method  Three light intensities[light transmittance 35.96%(L1), 13.00%(L2) and 4.75% (L3)], and two nitrogen levels[nitrogen application (N1) and no nitrogen application(N0)]were set up in pot experiments. The effects of light intensity and nitrogen on clonal reproduction characteristics and biomass allocation were analyzed.  Result  (1) Under the two nitrogen levels, the number of rhizome buds in L2 treatment was the highest. The number of clonal ramets of L3 treatment was significantly lower than that of L1 and L2 (P＜0.05). Nitrogen application significantly increased the number of clonal ramets and buds of D. dichotoma under different shading conditions (P＜0.05), with an increase rate of 124.7%(L1), 82.8%(L2) and 53.8%(L3) and 70.0%(L1), 125.7%(L2), 122.5%(L3), respectively. (2) Under the two nitrogen levels, the height of clonal ramets increased significantly (P＜0.05) with the increase of shading degree, and the length of leaves in L3 shading condition was significantly higher than that in L1 and L2 (P＜0.05), but there was no significant difference in leaf width (P＞0.05). Under nitrogen application level, the clonal ramet height of L1 and L3 treatments increased significantly (P＜0.05), the leaf length in the L1 treatment increased significantly (P＜0.05), and the leaf length in L3 treatment decreased significantly (P＜0.05). Both plant height and leaf length in L2 treatment did not increase significantly (P＞0.05). (3) Under the two nitrogen levels, the aboveground and underground biomass (dry weight) ratio and biomass allocation ratio of clonal ramets in L3 treatment were significantly higher than those in L1 and L2 shading treatments (P＜0.05). The rhizome distribution ratio was significantly lower than that of L1 and L2 (P＜0.05). The percentage of biomass and leaf allocation of each shading treatment was significantly higher than that of rhizomes (P＜0.05), and rhizomes were significantly higher than stems and fine roots (P＜0.05).  Conclusion  L2 treatment is more conducive to the formation of clonal ramets, and nitrogen application is conducive to the enhancement of clonal reproduction capacity. Clonal ramets of L3 treatment can adapt to low-light habitat by increasing plant height, leaf length and biomass leaf allocation ratio. Regardless of the light intensity and nitrogen level, D. dichotoma gives priority to ensuring the growth of feather leaves, followed by rhizomes. [Ch, 2 fig. 5 tab. 38 ref.]
2021, 38(1): 84-92.   doi: 10.11833/j.issn.2095-0756.20200277
[Abstract](53) [HTML](31) [PDF](9)
Abstract:
2021, 38(1): 93-102.   doi: 10.11833/j.issn.2095-0756.20200237
[Abstract](69) [HTML](23) [PDF](9)
Abstract:
Objective  With an exploration of the role of early light induced proteins (ELIPs) in photoprotection of bamboo, this study is aimed at providing reference for the further elucidation of the photoprotective mechanism in bamboo.  Method  The ELIP genes were isolated from moso bamboo (Phyllostachys edulis) leaves using qRT-PCR before an analysis was conducted of their expression profiles under different light conditions employing qRT-PCR and the function of one ELIP gene was initially validated by ectopic expression in Arabidopsis thaliana.  Result  All the three ELIP genes (PeELIP1, PeELIP2 and PeELIP3) isolated from moso bamboo, with 165, 179 and 182 amino acids encoded respectively have the light-harvesting chlorophyll a/b binding protein domain that consists of three α-helices transmembrane domains, indicating that they belonged with the chlorophyll a/b binding protein superfamily. As was shown in the phylogenetic analysis, PeELIPs were closely related to the ELIPs from monocotyledonous plants including Oryza sativa and Zea mays, which had a high homology of more than 72% and clustered in a same branch. With the employment of qRT-PCR, it was found that the three PeELIPs were weakly expressed in etiolated bamboo seedlings, but their expression was dramatically increased upon light treatment. Meanwhile, with the increase of light intensity and the duration of treatment with strong light stress, they were all upregulated significantly in the normal bamboo leaves. In addition, the over-expression of PeELIP3 in Arabidopsis thaliana inhibited the decline of Fv/Fm under strong light treatment, but it had no effect on non-photochemical quenching coefficient (NPQ).  Conclusion  In conclusion, at least three homologous genes of ELIPs can be identified from moso bamboo, all with light-inducible expression. On the other hand, the over-expression of PeELIP3 could alleviate the photoinhibition in transgenic Arabidopsis thaliana, implying that PeELIP3 might play a positive role in photoprotection. [Ch, 8 fig. 1 tab. 40 ref.]
2021, 38(1): 103-111.   doi: 10.11833/j.issn.2095-0756.20200212
[Abstract](75) [HTML](26) [PDF](2)
Abstract:
Objective  This research is aimed to study the effects of material tissue and the treatment method on the genome size of bamboo plants with the ultimate purpose to improve the genome size determination accuracy of bamboo plants.  Method  With the leaves and shoots of different bamboo species selected as materials, and the rice used as the reference standard while the nuclear staining time set for 9 different gradients, that is 1, 3, 5, 7, 9, 12, 18, 24 and 30 minutes, an investigation was carried out of the tissue sites and staining materials of different bamboo plants with the employment of flow cytometry.  Result  (1) With the same bamboo species, the leaves and shoots were similar in the fluorescence peak and genome size with the genome size difference range as narrow as 0.04~0.20 pg. (2) The 12 bamboo species are different in their nuclear staining time, with the fluorescence intensity of Sinobambusa tootsik, Sinobambusa tootisik f. albo-striata, Pseudosasa japonica var. tsutsumiana, Pseudosasa japonica f. akebono, Indocalamus decorus, Sasaella glabra f. albo-striata and Chimonobambusa mamorea f. variegata reaching the maximum within 1 minute, that of Bambusa multiplex and Phyllostachys sulphurea reaching the maximum within 3 minutes, that of Pseudosasa amabilis var. amabilis and Thyrsostachy ssiamensis reaching the maximum within 5 minutes, while that of Phyllostachys sulphurea (leaf) reaching the maximum within 7 minutes. (3) The fluorescence intensity of the 12 bamboos varies greatly from 1 to 30 minutes, all exceeding 5% except for the leaf of P. amabilis var. amabilis, T. ssiamensis, B. multiplex and the shoot of S. tootsik. In fact, the fluorescence intensity of P. japonica var. tsutsumiana and S. glabra f. albo-striata have reached 12.93% and 12.88% respectively. (4) As for the genome size of 12 bamboo species, 2 tropical woody bamboo species of B. multiplex and T. ssiamensis changed from (2.64±0.54) pg to (2.69±1.01) pg, however, that of the 10 temperate woody bamboo species changed from (3.76±1.51) pg to (5.73±1.85) pg; of the 10 temperate bamboo species, the genome size of Phyllostachys changed from (3.76±1.51) pg to (3.91±0.95) pg, yet that of the other bamboo genus changed from (4.82±0.54) pg to (5.73±1.85) pg, which is obviously larger than Phyllostachys.  Conclusion  (1) Both leaves and shoots of bamboo can be used as experimental materials to determine their genome sizes by flow cytometry. The nuclear staining time has a certain effect on the determination of the bamboo genome size with 3 to 5 minutes as the optimal staining time. (2)The genome size of tropical woody bamboo species is obviously smaller than that of temperate woody bamboo species while among the temperate woody bamboo species, the genome size of Phyllostachys is obviously smaller than that of the other genus bamboo species. [Ch, 1 fig. 5 tab. 29 ref.]
2021, 38(1): 112-119.   doi: 10.11833/j.issn.2095-0756.20200256
[Abstract](26) [HTML](28) [PDF](5)
Abstract:
Objective  This paper aims to explore the effects of N deposition on Phyllostachys edulis shoots and provide theoretical basis for improving bamboo shoot quality and human health.   Method  A field experiment was conducted in a subtropical Ph. edulis plantation and the effects of three different levels of simulated N deposition (control: 0 kg·hm−2·a−1, N30: 30 kg·hm−2·a−1, and N60: 60 kg·hm−2·a−1) on the contents of amino acids, nutrients (vitamin C, crude fiber, crude protein, and soluble sugar) and mineral elements in Ph. edulis shoots were studied.   Result  N deposition significantly affected the nutrient quality and mineral elements of Ph. edulis shoots. Nitrogen deposition significantly increased the contents of total amino acids, essential amino acids, and sweet amino acids (P＜0.05). High N deposition (N60) significantly increased the contents of umami amino acids, bitter amino acids, and aromatic amino acids (P＜0.05), while low nitrogen deposition (N30) had the opposite effect. Nitrogen deposition significantly increased the proportion of sweet amino acids (P＜0.05), but significantly decreased the proportion of essential amino acids, umami amino acids, bitter amino acids, and aromatic amino acids (P＜0.05), and significantly reduced vitamin C content(P＜0.05) but increased crude fiber content, and had no significant effect on the content of crude protein and soluble sugar. Nitrogen deposition significantly increased the contents of Se, Fe and Na but significantly decreased the content of Cu (P＜0.05). Low N deposition (N30) significantly increased Mn, Ca and Mg contents, while the N60 treatment was the opposite(P＜0.05).  Conclusion  Moderate N deposition has a certain promotion effect on nutritional components of Ph. edulis shoots, which is conducive to the improvement of bamboo shoot quality and human health. [Ch, 2 fig. 2 tab. 41 ref.]
2021, 38(1): 120-127.   doi: 10.11833/j.issn.2095-0756.20200161
[Abstract](124) [HTML](74) [PDF](13)
Abstract:
Objective  This research aims to study the effects of exogenous brassinolide (BR) on physiological characteristics of Phyllostachys edulis, and to provide theoretical basis and technical reference for future cultivation and management of Ph. edulis.  Method  The seedlings of Ph. edulis were used as test materials, and 6 kinds of brassinolide solutions with different concentrations[0(ck), 0.050 0, 0.010 0, 0.005 0, 0.001 0, 0.000 5 mg·L−1] were set up through hydroponic culture experiment to compare the differences in the growth characteristics, photosynthetic pigment, photosynthetic characteristics and antioxidant system of the seedlings.   Result  On the whole, compared with ck, brassinolide with different mass concentrations could promote the growth and development of Ph. edulis seedlings to varying degrees, improve the quality of photosynthetic pigments and photosynthetic capacity, and promote the synthesis of osmotic adjustment substances. Compared with ck, when the mass concentration of brassinolide was 0.005 0 and 0.001 0 mg·L−1, the superoxide dismutase activity of bamboo seedlings increased by 6.7% and 6.1%, respectively, oxidase activity increased by 14.6% and 13.7%, and catalase activity increased by 8.2% and 14.6%, respectively. The mass fraction of soluble protein increased by 31.5% and 31.2%, and the mass fraction of starch increased by 17.3% and 16.9%, respectively. However, compared with 0.005 0 and 0.001 0 mg·L−1 treatment, brassinolide treated with mass concentration of 0.050 0, 0.010 0 and 0.000 5 mg·L−1 had no significant effect on antioxidant capacity and osmotic adjustment ability of Ph. edulis seedlings.  Conclusion  Brassinolide can improve the photosynthetic capacity and stress resistance of Ph. edulis seedlings, and promote nutrient growth. The best concentration of brassinolide is 0.005 0−0.001 0 mg·L−1.[Ch, 5 tab. 42 ref.]
2021, 38(1): 128-137.   doi: 10.11833/j.issn.2095-0756.20200303
[Abstract](69) [HTML](28) [PDF](7)
Abstract:
Objective  With the changes of main mineral element contents in the annual growth cycle of the Paeonia ostii ‘Feng Dan’ measured, the current study is aimed at an analysis of the fertilizer requirement and nutrient diagnosis for the oil peony.  Method  With ‘Feng Dan’ (eight years old), an oil peony cultivar selected as the study subjects, the mineral elements content of roots, stems and leaves were measured across the growth stages of the oil peony.  Result  The content of P in roots, stems and leaves, and the content of N in roots and leaves decreased gradually as the growth cycle of the peony proceeds, while the changes of K and Mg vary from part to part. The content of Fe was significantly more than any other trace elements in the roots, stems and leaves, and increased first and then decreased across the growth cycle. All of the trace elements, except for Cu, have showed first an increase and then a decrease in content in the roots. As the process of fruit development advanced, the content of N increased, with the content of K in fruit pods and P in seeds displaying a trend of decrease, increase and decrease. The changes of mineral elements in roots, stems and leaves of the peony showed different degrees of correlation across the peony’ s growth cycle, with N、P、K、Fe and Mn closely related to most of the other mineral elements. The same mineral elements displayed different correlations with vegetative organs and reproductive organs.  Conclusion  Throughout one growth cycle, the oil peony ‘Feng Dan’ has a large demand for N and P from the leaf-growth stage to the current bud stage, and N and P fertilizers should be applied before the leaf-growth stage; and there is a large demand for N, P and K during the fruiting period, and it is recommended to apply N, P and K fertilizer after the flowering of the peony. Fe fertilizer should be applied before the budding stage (early March) while B and Zn fertilizers should be applied during the seed development stage from May to July to meet the demand of ‘Feng Dan’ plants for these three microelements. [Ch, 7 tab. 36 ref.]
2021, 38(1): 138-146.   doi: 10.11833/j.issn.2095-0756.20200190
[Abstract](40) [HTML](27) [PDF](2)
Abstract:
Objective  Aimed at a study of the color parameters and the pigment content of Juniperus colored leaves.  Method  Two-year-old cutting seedlings of Juniperus communis ‘Gold Cone’ (JC) and Juniperus×media ‘Pfitzeriana Aurea’ (JM) were used to determine the leaf color parameters (L*, a*, b*), relative content of photosynthetic pigments (chlorophyll a, chlorophyll b, carotenoids) and anthocyanins, with a correlation analysis conducted to establish the regression equation of leaf color parameters and pigment content.  Result  (1) The changing trends of leaf color parameters of JC and JM are different in different seasons: the L* and b* values of JC have the same changing trend and are always positive, and the a* value increases significantly in autumn and winter from negative to positive. The L* value of JM rises significantly in spring and summer, with the fluctuation of a* value unobvious, the hue always greenish whereas the b* value rises significantly in spring and summer with no fluctuation in autumn and winter, and the hue always yellow. The L* and b* values of JC in spring, summer and autumn are significantly higher than those of JM. (2) The relative content of anthocyanin in JC has a very significant negative correlation with L* and b* values, and a very significant positive correlation with a* value while JM photosynthetic pigments have a very significant negative correlation with b* value. (3) The results of the stepwise regression equation show that the a* and b* values can accurately predict the annual and autumn changes of the anthocyanin content of JC, and the b* and L* values can accurately predict the annual and summer changes in the photosynthetic pigment content of JM pigment changes.  Conclusion  The relationship between leaf color parameters and pigment content of the two color trees of Juniper genus is significantly correlated with differences in different tree species during in different periods and the leaf color of JC generally better than that of JM. The established regression equation of leaf color parameters and pigment content can help make an accurate estimation of leaf pigment content based on leaf color parameters. [Ch, 2 fig. 4 tab. 32 ref.]
2021, 38(1): 147-154.   doi: 10.11833/j.issn.2095-0756.20200163
[Abstract](44) [HTML](36) [PDF](5)
Abstract:
Objective  With the straw of Oryza sativa selected as raw materials, this study is aimed at an investigation of the dissolution behavior and regeneration characteristics of straw samples dealt with the LiCl/DMSO solvent system.  Method  With the national standard method employed, the four samples of straw (internode with knot, stem without knot, leaf and whole straw)were treated with the LiC1/DMSO system before an analysis was conducted of the general chemical composition of cellulose, hemicellulose, lignin and ash. On top of this, the effect of dissolution and regeneration of rice straw on the cellulose crystallization zone was investigated with the crystallinity calculated employing X-ray diffraction after the yield of lignin structural units produced by alkaline nitrobenzene oxidation was measured and the condensed degree of lignin was analyzed.  Result  (1) Both of stem and leaf with 1.0 h ball milling could be completely dissolved in LiCl/DMSO solvent system with a dissolution rate up to 10% even in the 8% LiCl/DMSO solvent system; (2) After water regeneration, more than 80% of the lignin could be retained with that of the stem reaching 87.5%; (3) The cellulose crystallinity was decreased from 37.8% to 27.5% for the leaf and from 43.1% to 26.5% for the stem; (4) The uncondensed units of lignin of all four samples were increased, as observed in the results of alkaline nitrobenzene oxidation.  Conclusion  (1) Both ball milling time and LiCl concentration affect the dissolution of rice straw in LiCl/DMSO solvent system; (2) In terms of regeneration, the chemical content displays high capacity and in comparison, that of the cellulose and lignin was the lowest in leaf sample while with a different ash distribution, the regeneration capacity of the leaf was higher than that of the stem; (3) After ball milling, the condensation degree of lignin decreases while the oxidation environment of nitrobenzene and homogeneous reaction was improved; (4) After regeneration, it was showed in the X-ray diffraction analysis that the crystalline region of cellulose was damaged to a certain extent and the crystallinity decreased. [Ch, 6 fig. 4 tab. 36 ref.]
2021, 38(1): 155-164.   doi: 10.11833/j.issn.2095-0756.20200279
[Abstract](57) [PDF](5)
Abstract:
Objective  With a quantitative analysis conducted of the changes in the landscape pattern in Shennongjia Forestry District due to the implementation of forest protection projects since 1990s as well as their driving mechanisms, this study is aimed to explore the effectiveness of the conservation in this region and provide a reference for the future ecological environment protection and rational land use.  Method  Supported by remote sensing (RS) and geographic information system (GIS) technology and taking Shennongjia Forestry District as the research object, with remote sensing images from three different periods of 1996, 2007 and 2018 selected as data sources, this paper has mainly employed land use transfer matrix, landscape pattern distribution center of gravity model and landscape pattern index.  Result  Between 1996 and 2018, the landscape of forest land and water areas has retained a stable and favorable state while there is a general decrease in the area of grassland and cultivated land showed; There has been a more significant tendency in the conversion of other land types to construction land and such changes mainly attribute to human factors.  Conclusion  Ecological protection and restoration projects such as returning farmland to forests in Shennongjia Forestry District have been rewarded with a better integrated landscape pattern, enhanced landscape diversity in spite of aggravated local fragmentation as well as more favorable socioeconomic and ecological space. On the other hand, due attention should be paid to threats against ecological security induced by the booming local tourism with various natural landscapes replaced by artificial patches. [Ch, 4 fig. 5 tab. 32 ref.]
2021, 38(1): 165-172.   doi: 10.11833/j.issn.2095-0756.20200168
[Abstract](67) [HTML](75) [PDF](8)
Abstract:
Objective  This study aims to discuss the governance effect of the National Key Soil and Water Conservation Project after implementation.  Method  Taking the small watershed of Zhangjia Village in Mengyin County of Shandong Province as an example, and soil and water conservation in basic spot and effect spot as the unit, the changes of land use, forest and grass vegetation coverage, soil and water conservation measures, and soil and water loss before and after the implementation of the National Key Soil and Water Conservation Project were compared and analyzed through investigation, measurement and field review, based on high-resolution remote sensing, UAV, mobile terminal and other technologies.  Result  (1)After the implementation of the project, there were 339 plot changes, covering an area of 870.60 hm2. The change direction was mainly from slope farmland/dry terrace into orchards, followed by slope farmland into dry terrace. (2)The basic annual forest and grass coverage rate was 31.13%, and the assessed annual forest and grass coverage rate was 45.69%. The coverage rate was mainly medium and high (60%–75%), and the improvement rate of forest and grass coverage was 14.56%. (3) The conservation rate of soil and water conservation measures was the highest in reservoir (100.00%), the lowest in millet workshop (55.56%), and the conservation rate of other soil and water conservation measures was above 80.00%. (4) The area of soil and water loss reduced by 400.39 hm2 in the evaluation year compared with the base year, the reduction rate of soil and water loss was 23.21%, and the degree of soil and water loss control was 76.78%.  Conclusion  Through implementation of the National Key Soil and Water Conservation Project, the ecological environment in the small watershed of Zhangjia Village in Mengyin County has been significantly improved, which is mainly reflected in the reduction of soil and water loss and the increase of forest and grass vegetation coverage. [Ch, 5 fig. 5 tab. 11 ref.]
2021, 38(1): 173-183.   doi: 10.11833/j.issn.2095-0756.20200306
[Abstract](34) [HTML](21) [PDF](3)
Abstract:
Objective  From the perspective of forest carbon sequestration demand, this study aims to calculate and analyze enterprise emission reduction cost, forest carbon sequestration demand price and policy influencing factors, so as to better understand the market demand potential of forest carbon sequestration and promote the development of forest carbon sequestration market.  Method  Taking Beijing, Shanghai, Hubei and Guangdong as the case areas, three carbon emission intensive representative industries, namely thermal power, chemical industry and steel, were selected to calculate the carbon marginal emission reduction cost of 89 emission reduction units of 2 759 samples by directional distance function method. Then, the Robin Stein game model was used to measure the demand price of forest carbon sink, and the cloud model was used to measure the demand price of forest carbon sink of enterprises in different industries and regions, and the impact of policy changes on the price was simulated.  Result  The average demand price of forest carbon sequestration in thermal power industry, steel industry and chemical industry was 631, 556 and 575 yuan·t−1 respectively, and the average value of enterprises in Shanghai, Beijing, Guangdong and Hubei was 305, 456, 877 and 715 yuan·t−1 respectively. Cloud model simulation analysis showed that with the increase of the proportion of carbon sequestration offset and the increase of carbon sequestration subsidies, the demand price of forest carbon sequestration of various industries and provinces and cities increased. With the increase of carbon tax collection rate, the demand price showed a downward trend.  Conclusion  The marginal cost of carbon dioxide emission reduction in different regions and different industries varies greatly and increases year by year. Forest carbon sequestration is the trend of future emission reduction. At present, thermal power industry enterprises have officially launched the national carbon emission trading market. The cloud model simulation results show that the chemical industry is more vulnerable to policy influence than the other two industries. Therefore, under the reasonable combination of allowable offset ratio and subsidy policy, thermal power and chemical industry will be the major demanders of forest carbon sequestration in the future, and the development potential of forest carbon sequestration market is huge.[Ch, 4 fig. 5 tab. 28 ref.]
2021, 38(1): 184-192.   doi: 10.11833/j.issn.2095-0756.20200243
[Abstract](34) [HTML](9) [PDF](4)
Abstract:
Objective  This study aims to investigate the relationship between environmental perception, sports experience and health efficacy of scenic spots.  Method  Using random sampling, the tourists in Lingjiu mountain forest sports town in Quzhou City of Zhejiang were investigated by questionnaire to obtain the relevant data. The structural equation was used to analyze the impact of environmental perception and leisure sports experience satisfaction of forest sports scenic spots on tourists’ environmental restoration perception.  Result  (1) The environmental perception satisfaction had a significant positive impact on tourists’ perception of environmental restoration. The mean value of standardized path coefficient was 0.26. The influence of the four dimensions on environmental restoration perception from large to small was ductility (0.29), charisma (0.27), compatibility (0.25), distance (0.23). Among the elements of environmental perception in forest scenic spots, the load of ecological environment quality on tourists’ satisfaction of forest environmental perception was the largest, which was 0.74. (2) Leisure sports experience satisfaction had a significant positive impact on tourists’ perception of environmental restoration (P＜0.05). The average value of standardized path coefficient was 0.86, and the degree of influence on the four dimensions of environmental restoration perception from large to small was distance (0.90), compatibility (0.88), charisma (0.84), ductility (0.82), which showed little difference between the four dimensions. In the satisfaction of leisure sports experience, the load of sports facilities and sports interest was the largest, both were 0.59. (3) From the difference of path coefficient, the effect of leisure sports experience satisfaction on environmental restoration sensitivity (0.86) was significantly higher than that of environmental perception satisfaction of scenic area (0.26).  Conclusion  Both the environmental quality of forest scenic spots and forest leisure sports experience have a significant positive impact on tourists’ perception of environmental restoration, but the impact of forest leisure sports experience is greater than that of scenic spots. The most important factor affecting the satisfaction of forest scenic spot environmental perception is the quality of ecological environment, and the biggest factor affecting the satisfaction of leisure sports experience is the richness of sports facilities and the interest of forest sports. For forest sports tourist attractions, more attention should be paid to how to improve the richness and interest of forest leisure sports. [Ch, 2 fig. 1 tab. 24 ref.]
2021, 38(1): 193-204.   doi: 10.11833/j.issn.2095-0756.20200234
[Abstract](38) [PDF](5)
Abstract:
The study of plant population ecology aims to explore the development dynamics, distribution of population, and its interaction with other biological and abiotic factors in the habitat, which is of great theoretical and practical significance for understanding ecosystem balance, biodiversity and ecological protection. Stellera chamaejasme is one of the typical poisonous weeds in degraded grassland. An investigation into its population ecology and reproductive biology can provide scientific and theoretical basis for the control and restoration, resource management, and ecological protection of degraded grassland of this type. In this paper, the research results on spatial distribution pattern, population diffusion and colonization of S. chamaejasme were summarized. The breeding system characteristics, pollination syndrome and reproductive allocation strategies of S. chamaejasme were expounded. The allelopathy and ecological function of S. chamaejasme were discussed. Finally, the future research was prospected based on the current research results. The main conclusions are as follows: the spatial distribution pattern of S. chamaejasme population shows clumped(aggregation), random and uniform distribution, and the distribution pattern of seed near the mother plant and its low germination rate affect the population diffusion. S. chamaejasme, with its self-incompatibility system, is a typical outcrossing plant, and its floral features show the pollination syndrome of moths and butterflies in order Lepidoptera. With the change of habitat at different altitude and slope direction, the reproductive allocation strategy of S. chamaejasme is different. S. chamaejasme can release allelopathy substances through root secretion or residual decay, and exert positive or negative effects on other species of grassland community by changing soil nutrients, so as to influence community structure and ecological function. In the future, studies on population ecology of S. chamaejasme should focus on the ecological mechanism of spatial distribution pattern formation, habitat selection of invasion, settlement and propagation in grassland communities, and the ecological relationship between population diffusion and grassland degradation. [Ch, 1 fig. 106 ref.]
2021, 38(1): 205-213.   doi: 10.11833/j.issn.2095-0756.20200138
[Abstract](84) [HTML](38) [PDF](5)
Abstract:
Mainly composed of vegetables, oil crops, medicinal plants, ornamental plants and dyewood, Brassicaceae is a plant that can be annual, biennial or perennial, also as the most important family of vegetable and oil crops in China. Wax, comprised with very long chain fatty acids and corresponding derivatives, a layer of protective structure formed on plant surface to adapt different environmental conditions, plays an important role in resistance to biotic and abiotic stresses. It helps maintain water balance, reflect ultraviolet rays, reduce external mechanical damage, decrease low temperature damage, resist invasion of bacteria and fungi, prevent fruit cracking and fight off insect invasion. This paper, with a brief review of the type, physiological function, genetic characteristics, biosynthetic and transport pathways of wax, is intended to provide reference for the study of wax metabolism in Brassicaceae plants. [Ch, 2 fig. 2 tab. 61 ref.]
2021, 38(1): 214-218.   doi: 10.11833/j.issn.2095-0756.20190731
[Abstract](84) [HTML](52) [PDF](2)
Abstract:
Objective   In order to clarify the control effect of different chemical insecticides on the larvae of the Melanotus cribricollis, a virulence test was carried out on the larvae stage for the present study.   Method   With 5.0% phoxim granules, 0.5% fipronil powder and 20.0% chlorantraniliprole suspension selected and mixed into sand and bamboo forest soil in a 1∶2 ratio with 5 concentration gradients, to observe the mortality rate of M. cribricollis after 24 hours in contrast with a control group where water was sprayed without any insecticides.   Result   The three selected chemical insecticides all have certain control effects on M. cribricollis, with the control effect from strong to weak: 5.0% phoxim＞0.5% fipronil＞20.0% chloranthrene Benzoamide. It was found that the 5.0% phoxim has the best control effect, with an LC50 of 0.190 0 g·kg−1, followed by 0.5% fipronil, with an LC50 of 0.950 0 g·kg−1, and 20.0% chlorantraniliprole which has the weakest control effect with a LC50 of 1.820 0 g·kg−1.   Conclusion   With control effectiveness, toxicity and control costs taken into consideration, 5.0% phoxim Phosphorus granules and 0.5% fipronil are suitable for the control of bamboo forest pests M. cribricollis, yet with the need to further explore the application methods and relevant technologies of forest chemicals. [Ch, 2 tab. 27 ref.]
2021, 38(1): 219-224.   doi: 10.11833/j.issn.2095-0756.20200268
[Abstract](75) [HTML](31) [PDF](28)
Abstract:
Objective  This study aims to explore the natural regeneration status of Alcimandra cathcartii, a National GradeⅠProtection plant, in order to better protect this species.  Method  By setting sample circles to investigate the natural regeneration of A. cathcartii, the spatial pattern and regeneration of this species were studied.  Result  (1) The ratio of index variance (S2) to mean of the distribution pattern (m) was 4.14, which was significantly greater than “1.00”, indicating that the distribution of individuals was uneven, and the distribution of saplings in the survey circle was cluster type. (2) 67 regenerated plants were recorded in 8 sampling circles. According to the diameter class distribution of the seedlings, the regeneration proportion of young, small and medium trees was 46.27%, 32.83% and 20.90%, respectively. The regeneration number showed a pyramid structure, indicating that the structure was relatively stable although the regeneration number was small. (3) The proportion of regenerated plants at 0°−90°, 90°−180°, 180°−270° and 270°−360° was 26.86%, 19.40%, 20.90% and 32.84%, respectively. There were some differences in the number of regenerated plants in each angle range, but the variance analysis of the number of trees showed there was no significant difference in the number of regenerated plants in different azimuth angles. (4) The regeneration of A. cathcartii was correlated with the distance between mother trees. Within the distance of 0−5, 5−10, 10−15, 15−20, 20−25 and 25−30 m from mother trees, the proportion of regenerated plants was 11.94%, 34.33%, 23.88%, 22.39%, 5.97% and 1.49% respectively. The regeneration was mainly distributed in the range of 5−20 m from the mother tree, accounting for 80.60% of the total number of regenerated plants. The variance analysis showed there were significant differences between the distance from the mother tree and the regeneration distribution of A. cathcartii.  Conclusion  The regeneration number of A. cathcarti is small and the distribution scope is narrow, so it is difficult to expand the population. Artificial promotion is suggested for its population generation and expansion. [Ch, 7 tab. 17 ref.]