[Objective] This study was aimed to analyze the structure of mangrove-forest community and its corresponding landscape characteristics, to provide valuable information for mangrove reforestation and protection, important for regional biodiversity conservation and ecological environment improvement in the future.[Method] Using Qi'ao Island as the study area, based on the datasets from interpretation of remote sensing images and field investigation, spatial-distribution of the mangrove-forest communities, population dominance and landscape pattern after low temperature damages were investigated.[Result] True mangroves are the dominant species in the study area, including two primarily exotic species (Sonneratia apetala and Sonneratia caseolaris) and three major local mangrove species, namely, Acanthus ilicifolius, Kandelia candel and Acrostichum aureum. Sonneratia apetala, with an area contribution of 85.17%, is absolutely the first dominant species. Other major species include Kandelia candel, Acrostichum aureum, and Acanthus ilicifolius community, with area contributions of 4.2%, 3.1%, and 2.65%, respectively. The total area contribution by the aforementioned species was 95.12%. Semi-mangrove plants primarily include Cerbera manghas, Heritiera littoralis and Pongamia pinnata, with relatively low importance. The biggest aggregation at population level was Laguncularia racemosa, followed by Pongamia pinnata. For other species, such as, Sonneratia caseolaris, Kandelia candel, Acrostichum aureum, Sonneratia apetala, and Acanthus ilicifolius, the aggregation was relatively weak. The highest aggregation at the community level was Sonneratia caseolaris and Sonneratia apetala, while the aggregation values for the communities of Acrostichum aureum, Excoecaria agallocha + Thespesia populnea were relatively low. Two exotic species, Sonneratia apetala and Sonneratia caseolaris, developed well in medium and shallow waters, which can inhibit the local species, Kandelia candel.[Conclusion] The mangrove-forest communities in Qi'ao Island are dominated by the Sonneratia apetala, Kandelia candel, Acrostichum aureum, and Acanthus ilicifolius community. The investigation at both population and community levels showed that the mangrove forest in the study area is in aggregated distribution. The results suggest that in the future program for species introduction and mangrove reforestation, Sonneratia apetala and Sonneratia caseolaris should be moderately introduced, which can strengthen the local mangrove planting, protect mangrove species diversity, and maintain the balance of mangrove ecosystems.

[Objective] The characteristics of regeneration of arbor trees in Quercus aliena var. acuteserrata forest in Taibai Mountain were studied to explore the relationship between regeneration and environmental factors, in order to provide a theoretical basis for understanding forest dynamics and forest management in this region.[Method] The status of regeneration and environmental factors of the Quercus aliena var. acuteserrata forest in Taibai Mountain were systematically investigated by setting up 21 and 12 sample plots on the south and north slopes, respectively from July to September 2009 and July to August 2010. The collected data were used to determine the regeneration density, diversity index, height-class structure, and the relationship between the regeneration and environmental factors using Excel 2003 and SPSS17.0 software.[Result] A total of 30 tree species with regeneration were recorded, in which Acer grosseri, Litsea moupinensis var. szechuanica, Quercus aliena var. acuteserrata, Symplocos paniculata, Crataegus hupehensis, and Viburnum betulifolium were the most important regeneration species. For each species, the importance value (IV) was more than 20%, and the IVs of six species accounted for 69.31% of the sum IVs of all regeneration species. The total regeneration density was 9 696.97 individual·hm^-2 and mainly concentrated at the seedling stage. The regeneration density in seedlings (H<1.3 m) was nearly 3 times of that in saplings (1.3 m ≤ H<3 m). Further analysis showed that the regeneration density was an inverse J-shape distribution with height-class. Regenerated saplings of Q. aliena var. acuteserrata with a height of 210-300 cm were not found in the forest, implying a failure to regenerate because that couldn't form a complete sequence of regeneration sizes in the understory. There were significant differences among different plots in regeneration densities and diversity indices (including species richness, Simpson index and Shannon-Wiener index), indicating that the distribution of regeneration was uneven, and tended to be patchy. Multivariate linear stepwise regression analysis showed that the main environmental variables influencing the total regeneration density were slope direction, total P content, slope gradient and organic matter content, which explained 73.2% of the total variation. Total P content and slope direction were the main environmental variables affecting regeneration diversity.[Conclusion] There were abundant regenerated tree species in the Q. aliena var. acuteserrata forest in Taibai Mountain, indicating certain regeneration ability. However, Q. aliena var. acuteserrata as the most dominant species couldn't complete natural regeneration in the understory, therefore, in forest management, creating open habitats (such as gaps in the forest) to promote regeneration, meanwhile, attention should also be paid to the effects of slope direction, total P content, slope gradient and organic matter content on regeneration, the habitat with the cooler wet slope, gentle slope, low soil P and organic matter content is conducive to the regeneration of arbor trees.

[Objective] Under co-inoculation with Pseudomonas fluorescens JW-JS1 and Xerocomus chrysenteron, the changes of enzyme activity and the microbial functional diversity in rhizosphere soil of NL-895 Poplar were studied to reveal the interaction mechanism by co-inoculation with phosphate-solubilizing bacteria and ectomycorrhizal fungi at the micro-ecological level.[Method] A pot experiment was conducted to investigate the effects of co-inoculation with Pseudomonas fluorescens JW-JS1 and Xerocomus chrysenteron(Xc) on the activities of soil enzymes (acid phosphatase, dehydrogenase and invertase), and the BIOLOG microplate method was applied to assay the microbial community and its function diversity in rhizosphere soil of NL-895 Poplar.[Result] The results showed that the soil enzymes activities (acid phosphatase, dehydrogenase and invertase) in rhizosphere of NL-895 Poplar with different inoculation were all higher than those of control, especially for acid phosphatase and invertase when co-inoculation with JW-JS1 and Xc. The BIOLOG plates analysis showed that AWCD values on day 150 after inoculation were generally higher than those of control (except for 24 hour and 48 hour), and the value first increased then stabilized with the prolongation of incubation time. After 96 hour incubation, the McIntosh index and Richness index of co-inoculation with JW-JS1+Xc were higher than single inoculation with Xc or JW-JS1 and those of control (P<0.05), but the Shannon-Wiener index and Simpson index were significantly lower (P<0.05). There was significant difference in the utilization ability of six carbon sources in BIOLOG microplates by soil microorganism in rhizosphere of NL-895 Poplar with different inoculation treatments (P<0.05).[Conclusion] The co-inoculation of Pseudomonas fluorescens JW-JS1 and Xerocomus chrysenteron may play roles in improving the activities of soil enzymes and enriching soil microbial communities. All of these are conductive to improve soil fertility and promote the growth of NL-895 poplar. The results also showed that co-inoculation with PSB + ECF could effectively increase the activity of soil enzymes and improve soil biodiversity compared with single inoculation with PSB or ECF, which could provide a theoretical basis for developing the compound microbial fertilizer in the future.

[Objective] This study aimed to test the suitability of TDP sensors with different lengths of probes to measure Moso bamboo (Phyllostachys edulis) sap flow and investigate the effect of age on the culm sap flow of Moso bamboo. Based on the measurements of individual culms, the transpiration water consumption of P. edulis forests in northern Guangxi, China was estimated by scaling up the sap flow of individual culms, which provided a basis for ecological and hydrological research of P. edulis forests.[Method] Microscope was employed to examine the hydraulic structure of Moso bamboo culm. The 5 mm-and 10 mm-length TDP probes were installed at the bottom of both 1-2 years old and above 3 years old ramet culms to monitor sap flow pattern at different time scales. Climate factors and soil water content were also measured synchronously.[Result] Vascular bundle were unevenly distributed in culm wall. The outer vascular bundles of the culm wall were small and dense, and the differentiation of the vessels was incomplete, while the inner vascular bundles of the culm wall were large and sparse, and the differentiation of the vessels was complete and the diameter was large. For the same culms, mean sap flow measured by 10 mm-length TDP probe was 3.03 times higher than that measured by 5 mm-length TDP probe, and the difference between them reached significant level. Based on the measurement of 10 mm-length TDP probe, the sap density of 1-2 years old culms was significantly higher than that of above 3 years old culms during midday time in July, while the sap density between them were nearly same during early morning and late afternoon. The daily sap flux in 1-2 years old culms was higher than that in above 3 years old culms during the measured growing season and the mean daily sap flux was 51.15 g·cm^-2 d^-1 and 33.80 g·cm^-2 d^-1 for 1-2 years old and above 3 years old culms, respectively. Considering culm age and diameter, the water use of Moso bamboo forest located in northern Guangxi was estimated based on culm sap flow. The up-scaled water use ranged from 0.01-0.72 mm·d^-1 with the average of 0.31 mm·d^-1.[Conclusion] The 10 mm-length TDP probe was more suitable for sensing sap flow of Moso bamboo than the 5 mm-length TDP probe. The 1-2 years old culm had higher maximal sap flow density and larger daily sap flux than those of above 3 years old culm. Thus culm age was another key factor that must be considered besides culm diameter in estimating stand-scale water use based on culm-scale sap flow measurement.

[Objective] The present paper analyzed geometric morphology of 10 species of sphingid adults using geometric morphometric method to explore the feasibility of geometric morphometry on digital classification of sphingid moths for providing new morphological foundation on realizing digital classification of moths progressively.[Method] In the first step, geometric morphometric analysis was carried out. Right forewings of 10 sphingid species were used as research objects and 17 intersections of wing veins were selected as landmarks according to specific order, and coordinate data were obtained. Procrustes superimposition was applied to data of the 17 landmarks to remove non-shape variation from the landmark coordinates such as placing location, direction and sizes; and further, relative warp analysis was used to the new landmark coordinates to obtain effects of 17 landmarks to the 10 sphingid species. In the second step, multivariate statistical analysis was applied to the data collected by geometric morphometric analysis. One-way variance analysis was used for significant test of difference of landmark coordinates firstly; then, principal component analysis of the Procrustes transformed data-set was implemented; at last, discriminant analysis was carried out on the first three components.[Result] The result showed that Landmarks 2, 4 and 5 had relative large contributions on the classification of the 10 sphingid adult species according to relative warp analysis. All of the 17 landmarks had significant difference and could be used for the classification of those 10 Sphingidae adult species by using one-way variance analysis. The accumulated rate of contribution of three principal components of the principal component analysis reached 97.7%, which could be used as variables of the classification and identification of the 10 sphingid adult species. The accuracy of original and cross validation tests reached to 100% and 99.7%, respectively. Classification and identification of the 10 sphingid moths were realized.[Conclusion] It was indicated that geometric morphometric analysis could be used to identify the sphingid adults accurately and would be useful in gradually realizing the automatic recognition of moths in the future.

[Objective] This study aimed to investigate the rotifer community structure and water environmental factors in Fujin National Wetland Park, and give a comprehensive evaluation for the water quality of this wetland park.[Method] Eleven sampling sites were established in Fujin National Wetland Park. We used the plankton nets to collect the samples in these sites from May to October in 2015 and then identified them under the microscope. Meanwhile we tested the physicochemical index of the wetland water. The biodiversity index and trophic state index were used to evaluate the water quality.[Result] The result showed that 37 rotifer species belonging to 16 genera were detected in Fujin National Wetland Park. The common dominant species in three seasons of Spring,Summer and Autumn were Brachionus calyciflorus, Lecane luna and Monostyia lunaris. The abundance and biomass of the rotifers varied in the range of 52-264 ind·L^-1 and 0.042 4-0.212 9 mg·L^-1 respectively. The diversity indexes of Shannon-Wiener, Margalef and Pielou were in the range of 1.698-3.262, 0.590-1.480, 0.583-0.927, respectively. The average trophic state index in Fujin National Wetland Park water was the highest in summer, and the lowest in spring. In the 11 sampling points, the highest trophic state index occoured at the No.7 sampling point where water enters the park from a ditch.The average trophic state index of the 11 points was 51.08.[Conclusion] From the analysis of the indicator species, the diversity index and the comprehensive index, it was concluded that the water quality was at a level of middle nutrition or slight eutrophication in Fujin National Wetland Park, 2015.

[Objective] This study aimed to analyse the community composition of waterbirds, especially endangered birds such as cranes and storks, in different habitats of Khanka Lake and to provide a scientific basis for their conservation and management.[Method] We investigated the characteristic parameters of the waterbird community systematically from May 2014 to April 2015, and in December 2017 at six habitats in four regions of Hugang wetland, Longwang Temple, Dongbeipaozi Wetland and Qingshan Reservoir in Khanka Lake.[Result] In Khanka Lake, a total of 364 063 individuals from 85 species, 11 families and 7 orders were recorded; the wetland had the largest area, and hence the greatest number of bird species, and the highest diversity index of birds, dominated by Anseriformes and Charadriiformes. The woodland and shrubland had the fewest number of species because of the smallest area, whereas the shrubland had the lowest diversity index, and the composition of waterbirds was dominated by herons. Among the four regions, the diversity of waterbirds in Hugang was the highest, followed by Longwang Temple, and Dongbeipaozi Wetland, and Qingshan Reservoir was the lowest. There was a significant difference in the waterbird population sizes for the different regions due to the different habitats.[Conclusion] The population sizes of ducks and cranes in Khanka Lake decreased due to expanding habitat conversion and due to anthropogenic influences, especially the expansion of farmland and the shrinkage of wetlands and meadows in Longwang Temple and Dongbeipaozi Wetland, which were the main breeding sites for red-crowned cranes, white-naped cranes and oriental storks. We suggest that a habitat-based management strategy should be formulated for the conservation of waterbird communities in Khanka Lake.

[Objective] There is contradiction between the improving quality and increasing efficiency at the same time in wood sawing. The aims of this study were to analyze the influences of the side edges on the surface roughness using circular saw with different parameters of side edges, to solve the contradiction between high feed speed and the better surface roughness, and expected to provide references and guidance for designing the new type of woodworking circular saw.[Method] The concept of the sawteeth with mic-zero degree radial clearance angle was put forward in this paper. The experiments were carried out on the northeast China ash(Fraxinus mandshurica) and high density fiberboard(HDF) as materials and nine kinds of circular saw blades with different sawteeth side edge parameters were used with different feed speed, so as to investigate the influences of different radial clearance angles and straight length of zero degree radial clearance angle on the surface roughness(R_a).[Result] The surface roughness increased with the increase of feed speed, when the radial clearance angle is decreased, the surface roughness saw is decreased.The surface roughness of the sawteeth formed by the sawteeth with radial clearance angles was higher than that of the sawteeth with the sawteeth had a mic-zero-degree radial clearance angle. Especially when the straight length of zero degree radial clearance increased from 0 to 0.5 mm, the decrease trend was the most obvious.[Conclusion] The surface roughness depends on the depth of the saw notch to a certain extent. A small part of side edge which formed the sawing surface participates in actual cutting, and the length of this part of side edge is approximately equal to the feed per tooth. The sawteeth with mic-zero degree radial clearance angle can improve the surface quality of sawing. Besides, under the condition that the other cutting factors remain unchanged, the surface roughness can be improved and the friction also can be reduced between side edges and sawing surface by increasing the feed speed.

[Objective] In order to study the complex pyrolysis behavior based on biomass components, the structure composition and micromorphology of the hemicellulose of apricot shell were analyzed, and its pyrolysis properties and product formation rule might be expected to provide theoretical basis for its thermal chemical utilization.[Method] Apricot shell hemicellulose were separation by the alkali extraction and ethanol purification method. The composition, structure and microstructure were characterized by infrared spectrometer, nuclear magnetic resonance imaging, scanning electron microscope. The pyrolysis properties of apricot shell hemicellulose were investigated by thermogravimetric analysis and thermal infrared continuous analysis.[Result] The hemicellulose was isolated from apricot shell at a rate of 29.44%, and the FTIR spectrum characteristic absorption peaks were mainly concentrated in 1 620-600 cm^-1 which showed that the main components of hemicellulose were xylose of pyran ring structure. ¹H-NMR showed that apricot shell hemicellulose was the main chain of xylan composed of β-D-pyran xylose, which connected 4-O-methyl-α-D-glucuronic acid in xylose C-2 and α-L-furan arabinose in C-3. The SEM showed that hemicellulose was reuniting, the microstructure was approximate spherical structure, and the hemicellulose structure had some damage. Apricot shell hemicellulose main pyrolysis temperature ranged in 210-380℃, there were a shoulder peak at 240℃and a weightlessness peak at 308℃. The weightlessness process was at the end of the 600℃, the pyrolytic carbon residue content was 25.33% at 800℃. The pyrolysis product of apricot shell hemicellulose reached the highest at 310℃, small molecule gas products mainly include CO₂, CO, and CH₄, and CO, CO₂ were far higher than CH₄.[Conclusion] The content of hemicellulose in apricot shell was 29.44%, which was the main chain of β-D-pyran xylose xylan, and had an approximate spherical structure. Pyrolysis products were mainly CO₂, CO and acetic acid, furfural and acetone. The result of this study would provide a theoretical reference for the thermochemical transformation of the apricot shell hemicellulose.

[Objective] In view of the deficiencies that spray droplets were wider in flat-fan nozzle of plant protection machinery, and particle size uniformity were insufficient, a new type of nozzle structure based on the coupling of jet and impinging jets was proposed to improve the spray droplet size uniformity and the droplet spectrum.[Method] Using photosensitive liquid phase curing molding process of rapid prototyping manufacturing technology and C-UV9400 stereoscopic light modeling resin material, the flat-fan nozzle and impinging nozzle were produced which had the same exit shape, exit diameter(d₁=1 mm) and groove angle(α=30°). The droplet size and droplet distribution of the two kinds of nozzles were obtained according to the test system for atomizing performance of nozzle, and the uniformity of the particle size was evaluated in terms of the international criteria for distribution span.[Result] At the position 100 mm away from the nozzle exit, when the spraying pressure changed within the range of 0.3-0.8 MPa, it was found that the S value of the distribution span of flat-fan nozzle and impinging nozzle were respectively between 1.65-1.82 and 1.07-1.23, in which the smaller S value stands for better uniform and narrower spectrum, and the spraying performance test system showed that the droplet were more concentrated; the droplet size of flat-fan nozzle tended to be stable when the spraying pressure was greater than 0.6 MPa, and the droplet size of impinging nozzle decreased with the increase of spraying pressure, which indicated that the impinging nozzle had a variable pressure regulating performance with wide pressure regulating range; large droplets will be formed after impact, and larger droplets with a certain speed had better penetration performance and anti-drift ability. Besides, a multiple regression model of droplet size was established to provide a basis for selecting nozzle to achieve a better pest control.[Conclusion] The impinging nozzle based on the coupling of jet and impinging jets had the characteristics of improving particle size uniformity, narrow droplet spectrum, wide range of pressure regulation and better anti-drift ability. It can provide technical support for developing precision sprayer.

Mangroves are composed of a large group of salt-tolerant plant communities growing in tropical and subtropical intertidal estuarine zones, which are distributed approximately in the area between 30° N and 30° S latitude. Rhizophora genus is a kind of mangroves,and all woody plants located in tropical and subtropical intertidal coastal regions, and comprises of 8 species, including R. stylosa, R. apiculata, R. mucronata, R. mangle, R. harrisonii, R. racemosa, R. annamalayana and R. samoensis. Those plants have the characteristics of salt stress, high mineral composition, strong reducibility and frequent tides, which make plants extremely competitive for nutrition and space. The special growth environment entriches the diversity of endophytic fungi in Rhizophora, and it is bound to produce active molecules with biological activity and unique chemical structure different from other ecosystems. So far, the endophytic fungi isolated from Rhizophora genera are reported with 23 orders, 41 families and 64 genera. Amongst, Pestalotiopsis, Penicillium and Mucor have been widely studied. Meanwhile, 195 secondary metabolites have been identified from the Rhizophora endophytic fungi, including alkaloids, terpenoids, coumarins, ketones, quinones, anthraquinones, peptides, phenolic acids, lactones and other compounds. Some secondary metabolites with unusual structures are identified in Rhizophora endophytic fungi. Novel hybrid sesquiterpene-cyclopaldic acid metabolites with unusual carbon skeletons, pestalotiopens A and B (83, 84), pestalotiopsones A-F (107-112) are obtained from the endophytic fungus Pestalotiopsis sp. JCM2A4 is isolated from the leaves of the Chinese mangrove, R. mucronata. Most of them show antitumor, antibacterial, antioxidant activities. Some compounds have significant bioactivities, as exemplified by pestalpolyol 1 (119), a novel polyketone derivative isolated from P. clavispora. Compound 119 has a strong inhibitory effect on mouse lymphoma cell line L5178Y with an IC₅₀ value of 4.10 μmol·L^-1. The indole diterpene alkaloids, rhizovrin A, B and F (46, 47, 50), isolated from endophytic fungi Mucor irregularis QEN-189, have strong inhibitory effects on lung cancer cells A549, with IC₅₀ values of 11.5, 6.3 and 9.2 μmol·L^-1, respectively, as well as inhibitory effects on leukemia myeloid cells HL-60, with IC₅₀ values of 9.6, 5.0 and 7.0 μmol·L^-1, respectively.

[Objective] By investigating the storage and structural characteristics of the coarse woody debris (CWD) in a subtropical evergreen broad-leaved forest in Jinyun Mountain, this study aims to promote the understanding of the material cycling process of woody debris in evergreen broad-leaved forests, and to provide fundamental data for global carbon sequestration related studies.[Method] In two permanent monitoring plots (with a total area of 1 hm²), we quantified the storage of CWD and checked the proportion of CWD by varying size classes, types and decay classes. In addition, we looked into the differences in the storage of CWD at different topographic positions to learn how topography affect the spatial distribution of CWD.[Result] The total storage of CWD on Jinyun Mountain was 38.42 t·hm^-2, among which logs, snags, branches and stumps totaled 27.70, 4.91,2.91 and 2.90 t·hm^-2, respectively. The species composition of CWD was similar to that of the above-ground forest community. Castanopsis fargesii was the dominant tree of the forest community, and it also made up 88.44% of the CWD. Logs and snags (>35 cm diameter-class) were the major components of CWD, and a majority of the CWD was found in the medium (63.20%) and late (23.01%) decay classes. Topographic position had a significant effect on the accumulation of CWD; the storage of CWD on the slopes and in the valleys were larger than the CWD storage on the ridges.[Conclusion] The storage of CWD in Jinyun Mountain was at a high level when compared to the existing cases of the evergreen broad-leaved forests elsewhere. CWD is mainly dominated by medium-and late-decay, and large-sized C. fargesii snags and logs. It was mainly distributed on the slopes and in the valleys. Human disturbances and removal of CWD should be controlled in Jinyun Mountain to retain a combination of trees, snags, and logs within forests for sustainable forest management.

[Objective] This study aims to investigate the causes for degradation of Phyllostachys edulis forest under mulching management (straw + bamboo leaf + rice chaff), in order to provide a theoretical basis for the restoration of degraded P. edulis forest.[Method] Bamboo stands with different mulching ages (1, 2, 3 a) and non-mulching (Control) stands were selected, soil pH value, nutrient contents, enzyme activities and microbial biomass in 0-40 cm soil layer were measured, respectively.[Result] With the increase of mulching years, the soil pH value gradually reduced, i.e. soil acidification. The content of soil organic matters increased with the increase of mulching years. Soil total nitrogen (TN), total phosphorus (TP), total potassium (TK) content increased gradually, and they were significantly higher than that in non-mulching stand (P<0.05). Contents of soil available nutrients (available N, available P, available K) increased and followed by a decrease, and peaked in mulching 1 a stand. Contents of soil available nutrients in mulching 1 a stand were significantly higher than that in the non-mulching stand (P<0.05), while they were significantly lower in mulching 3 a stand than that in the non-mulching stand (P<0.05). With the increase of mulching years, soil C/N and N/P gradually increased, N/K increased first and followed by a decrease, while P/K gradually decreased. Urease and sucrase activities increased first and followed by a decrease with the increase of mulching years, and peaked in mulching 1 a stand. While protease, catalase and acid phosphatase activities gradually decreased. Soil microbial biomass increased first and followed by a decrease with the increase of mulching years, and it was the largest in mulching 1 a stand. Bacteria and actinomyces biomasses showed the same variation tendency as the microbial biomass, while fungi biomass gradually increased. Aerobic bacteria biomass increased first and followed by a decrease, and it was significantly lower in mulching 3 a stand than that in the non-mulching stand (P<0.05). Ratio of fungi biomass and bacteria biomass (F/B) showed a decrease first and followed by an increase, and there was no significant difference in mulching 3 a stand and the non-mulching stand (P>0.05).[Conclusion] Compared with mulching 1 a Moso bamboo forest, long term mulching management may lead to soil acidification, the imbalance of nutrients proportions, decreasing of enzyme activities and change of soil microbial flora, resulting in soil deterioration and the degradation of P. edulis forests. Therefore, rotated mulching management (mulching 1 a and then recuperating 1 a) should be recommended in practice. In addition, mulching materials should be removed in time at shooting period to reduce the amount of residue, and the rational application of chemical fertilizer should also be considered.

[Objective] This paper investigated the variation of soil nutrients and oligotrophic bacterium, Acidobacterium communities during continuous planting of Cunninghamia lanceolata plantation in Kaihua, Zhejiang Province, to reveal the molecular ecological mechanism of Acidobacterium causing soil fertility changes in different types of C. lanceolata plantations. This study aimed to provide scientific basis for the adjustment of C. lanceolata stand structure, the scientific management of soil resources as well as the construction of healthy soil ecosystem in this area.[Method] The soil samples at different depths (0-20 cm, 20-40 cm) were collected from three different plantations:Pinus massoniana plantation(served as control);the first rotation of C. lanceolata plantation established after the clear cutting of P. massoniana, and the natural regeneration second rotation of C. lanceolata plantation, in Kaihua Forestry Farm in Zhejiang. Nutrient contents, physical and chemical properties of soil were analyzed. Then, the bacterial 16S rDNA in soil was analyzed using high-throughput sequencing.[Result] 1) The replacement of P. massoniana plantation with C. lanceolata plantation led to a significant decrease in pH value, alkali-hydrolyzable nitrogen, available phosphorus and available kalium content(P<0.05). The soil fertility was ranked as the order of P. massoniana plantation > the first-rotation C. lanceolata plantation > the second-rotation C. lanceolata plantation. 2) On the phyla level, Acidobacteria were dominant in soil bacteria of the three forest types, accounting for 32.68%-49.17%. The Acidobacteria proportion in 0-20 cm soil layer of the second-rotation C. lanceolata plantation was significantly higher than that of P. massoniana plantation (P<0.05). 3) A total of 18 groups of Acidobacteria were detected and classified, among which Gp2 was the dominant group representing 47.74%-68.07% of the Acidobacteria. Gp1 occupied the second ranking, accounting for 18.35%-29.72%, followed by Gp3, accounting for 13.30%-22.41%. The dominance of Gp2 in Acidobacteria group was strengthened, and Gp3 had the trend of changing from dominant bacteria to subdominant bacteria. The relative dominance of Gp1 was significantly negatively correlated with soil pH(P=0.035), and that of Gp2 had a significantly negative correlation with available P(P=0.010), while Gp10 had a significantly positive correlation with soil pH(P=0.035).[Conclusion] With the increasing rotation of plantation, the soil available nutrient level was decreased, while the proportion of Acidobacteria was increased. The dominant genera within Acidobacteria varied with the soil environment, suggesting that Acidobacteria played important roles in soil nutrient cycling in C. lanceolata plantation.

[Objective] To elucidate the molecular mechanism for enhancing photosynthetic capacity of the exocarp of Carya carthayensis fruits pollinated by Carya illinoensis in order to provide a theoretic basis for further research on metaxenia.[Method] Transcriptome sequencing was performed for exocarp of C. cathayensis respectively pollinated by C. cathayensis (marked as hp) and C. illinoensis (marked as pp) with samples collected 65 days after pollination (65DAP) when the fruit rapidly expanding in size. Gene enrichment analysis was conducted for pathways of chlorophyll synthesis, photo-response and carbon assimilation in combination with variation in chlorophyll content, photosynthetic rate and activity of key enzymes involved in the photosynthesis.[Result] Compared to the fruit pollinated with hp, the chlorophyll content, photosynthetic rate, Rubisco activity, and phosphoenolpyruvate carboxylase (PEPC) activity of exocarp in the fruit pollinated with pp were 1.31 (P=0.047), 1.12 (P=0.000 43), 1.65 (P=0.036), and 1.23 (P=0.001 3) folds, respectively. A total of 32 908 scaffolds were generated by transcriptome sequencing, and 66 photosynthesis-related genes were screened from 1 894 differentially expressed genes (DEGs) (P <0.05,fold change>1.5), which were mainly involved in pathways of chlorophyll synthesis and photosynthetic carbon fixation. The expression of magnesium-chelatase subunit (CHLH), agnesium-protoporphyrin IX monomethyl ester cyclase (CRD), and chlorophyll(ide) b reductase(NYC) of the fruit pollinated with pp was significantly up-regulated while that of pheophorbide a oxygenase (PAO) was significantly down-regulated in the chlorophyll biosynthesis pathway, and the expression of 16 light harvesting pigment protein complexes (LHCⅡ)-coding genes, ribulose bisphosphate carboxylase/oxygenase activase (RCA), alpha carbonic anhydrase (CA) in the photosynthetic carbon fixation pathway were significantly up-regulated. 42 genes involved in photoprotection of exocarp are also showed significantly high expression in the fruit pollinated with pp than those in the fruit pollinated with hp.[Conclusion] In the rapid growth period of Carya carthayensis fruits, the expression of magnesium-chelatase subunit (CHLH), agnesium-protoporphyrin IX monomethyl ester cyclase (CRD), chlorophyll(ide) b reductase (NYC), light harvesting pigment protein complexes-coding genes (LHCⅡ), light repair protein-coding genes (PSAN, PSAB27, STN7), 38 heat shock proteins (HSP), ribulose bisphosphate carboxylase/oxygenase activase (RCA) and alpha carbonic anhydrase (CA) was significantly up regulated for the pp cross combination. It indicates that the significantly up-regulated expression of genes involved in chlorophyll synthesis, light capture and carbon assimilation might be related to the significantly higher photosynthetic rate in the exocarp of pp cross combination.

[Objective] Poplar (Populus) is widely planted in China and usually used as a model tree. As conserved molecular chaperon, plant BAG proteins play critical roles in growth, development and stress responses. Study on the evolution and biological functions of Populus BAG genes is useful for genetic improvement of tree species.[Method] Arabidopsis BAG proteins were used as keywords to search online database (https://phytozome.jgi.doe.gov/) in order to identify the homologous BAGs from poplar (Populus trichocarpa), rice (Oryza sativa) and moss (Physcomitrella patens). Protein structures and evolutionary relationship of these BAG proteins were analyzed using the bioinformatic method. Tissue expression patterns and stress (drought and heat) responses of Populus BAG genes were detected based on the microarray (http://bar.utoronto.ca/) and qRT-PCR data.[Result] P. trichocarpa contains fourteen BAG genes, respectively named as PtrBAG1 to PtrBAG14 according to the international rules for nomenclature (ordered on their positions on the chromosome). BAG proteins are relatively conserved among poplar, Arabidopsis, rice and moss. These Populus BAG proteins are divided into two subfamilies. The members in subfamily Ⅰ contains an UBL domain, suggesting that these proteins might function as bridges to assist the degradation of some proteins. The members in subfamily Ⅱ have an IQ domain, implying the potential roles of these proteins in Ca²⁺ signaling. Poplar BAG genes exhibited different stress (drought and heat) responses. For example, heat treatment resulted in visible changes in BAG expression. Of them, BAG1, BAG4, BAG6, BAG7 and BAG8 were activated whereas others were suppressed by heat stress. By contrast, there were few alterations in the expression of most BAG genes under the treatment of drought. Particularly, heat treatment induced up regulated expression of BAG4 and BAG6 by 90 folds. Tissue expression analysis indicated that most of BAGs had little expression in detected tissues (root, leaves, shoot, seedling, female catkins, male catkins and xylem). However, BAG2 and BAG12 were highly expressed in xylem.[Conclusion] Poplar BAG family contains 14 members, which are basically divided into two subfamilies. These BAG proteins are closer to BAG homologs from Arabidopsis and rice than those from moss. All poplar BAG genes are responsive to heat stress but not to drought stress. In particular, BAG4 and BAG6 are most highly induced by heat treatment. BAG2 and BAG12 are likely involved in wood formation.

[Objective] The flowering phenology, flowering synchronism, seed setting and impacting climate factors of clones of the second-generation clonal seed orchard of Pinus massoniana were studied to evaluate the synchronization rule of clones, guide seed orchard management and production as well as improve seed genetic quality and yield.[Method] For two consecutive years, we investigated 22 clones in dwarfed second-generation clonal seed orchard of Pinus massoniana into the normal flowering and fruiting period in Laoshan Forest Farm in Chun'an County of Zhejiang province, including flowering phase, flower number and fruit characteristics, to analyze the flowering phenology and flowering synchrony index.[Result] The flowering period of both female and male flowers of all clones was 8-17 days. The initial flowering in 2014 was 6 days later than in 2013, and the lasting period was shortened by about 6 days relative to 2013. Overall, there were small differences in flowering period between female and male flowers in the same year, bigger differences were found among years in the initial time and peak time of flowering, and the flowering of female and male flowers of the same clone were more synchronized in 2014. The flowering phenology of clones was different greatly between the two years, related to climate during the flowering phase, which caused decrease of flowering synchronicity and increase of variation of flowering synchrony index, ranging from 0.041 to 0.556 and 0.284 to 0.802 respectively in 2013 and 2014. The average coefficient of variation of clones was 32.3% and 16.8%, respectively. When a clone was used respectively as male and female parent, the difference level of flowering synchronization was small within the same year. The level of flowering synchronization in male parent was higher than that as female parent. There was a significant difference between the two years in synchronism index when respectively used as male, female parent and for selfing. Compared with 2013, the flowering synchronization index in 2014 was significantly increased, but there was no significant difference in self-compatibility index between the two years. Correlation analysis showed that the clones with more female flowers had more fruits; and the clones with longer flowering period of female flowers had higher fruit-setting rate. There was significant positive correlation between the peaking time and flowering duration of female flowers and the weight of thousand seeds.[Conclusion] The second-generation clonal seed orchard of Pinus massoniana in Laoshan Forest Farm of Zhejiang Province had good flowering synchrony between female and male flowers, no asynchrony was found among the clones. The pollinating period of female flowers and the pollen dispersing period of male flowers of the mating pairs affected the quality of seeds and fruit setting rate. The synchronism of clone was influenced by meteorological factors. Observations in two consecutive years indicated that there were differences among clones in flowering synchronization level, which was made by the differences in flowering phenology of clone, and the differences were related to the genetic background of the parental clones in the second generation clonal seed orchard. The synchronicity of pollen dispersion period was higher when used as male parent than the synchronicity of the pollinating period when used as female parent. The flowering synchronization index showed a negative correlation when a clone uses respectively as male and female parent. The possibility of self-crossing of 1/3 of the clones in the seed orchard was higher than the average level of out-crossing, which was the factor that should be taken into account in the management of seed orchard and the selection of clones.

[Objective] Homalota nanjingensis is a new species found under the bark of Pinus massoniana infected by Bursaphelenchus xylophilus. There were high spatial and temporal encountering probabilities between the H. nanjingensis and the main secondary pests (such as species of Cerambycidae and Scolytidae), showing obvious following phenomenon. Thus, H. nanjingensis could be used as carrier insect with pathogenic organisms to control trunk-boring pest. The investigation of the morphological characteristics, adult feeding habits, and circadian activity rhythm of H. nanjingensis at different developmental stages was conducted in this study to provide references for further research and application.[Method] The morphological characteristics of H. nanjingensis larva, pupa, adult were observed and described. Adult feeding habits were studied by indoor-rearing and mouthparts-dissection. The circadian activity rhythm was detected by using "pitfall traps".[Result] Experimental investigation showed that H. nanjingensis larva are oligopod, chewing mouthparts, well-developed baenopoda, exarate pupa. The body length is about 1.5-2.0 mm, and body is strongly flattened dorsoventrally, and parallel-sided; The head, elytra and abdominal tergite have VI-Ⅷ segments with dark brown color, and the other parts of the body are yellowish brown. The adults preferred to feed artificially killed springtails, young maggots and larvae of long-horned beetle. When very hungry, it also fed on larvae of Scolytidae, Curculionidae, Elateridae, Formicidae, Labiduridae. We have not found that they preyed on living organisms in the course of experiment. Circadian activity rhythm of H. nanjingensis adult showed two peak hours:8:00-11:00 am and 20:00-22:00 pm.[Conclusion] Homalota nanjingensis adult is necrophagy, and its circadian rhythm is influenced by temperature.