2018 Vol. 35, No. 1
To determine the relationship between spatial structure and regeneration dynamics of a Phyllostachys edulis stand, an experiment was conducted in Mount Tianmu National Nature Reserve of Zhejiang Province. Data was taken from Ph. edulis stand in 2010, 2012, 2014. Fourur spatial structural indices, namely, nearest bamboo number, uniform angle, neighborhood comparison, and competition index, were selected to describe spatial structural characteristics of the bamboo. A principal component analysis was used for analysis. Results indicated an order of importance for spatial structural indices affecting Ph. edulis growth as nearest bamboo number > neighborhood comparison > competition index > uniform angle, and an order concerning importance of spatial structural indices affecting Ph. edulis death as nearest bamboo number > competition index > neighborhood comparison > uniform angle. New bamboo was apt to grow in an area where the nearest bamboo number was < 4 or > 7; whereas, old bamboo was apt to die if the nearest bamboo number was > 7. Living bamboo, new bamboo, and dead bamboo all presented a clustered distribution pattern with no significant differences at the uniform angles (P>0.05). Living bamboo had an intermediate status with new bamboo in a sub-dominant state and dead bamboo in a relatively disadvantageous state. All showed highly significant differences in neighborhood comparison (P < 0.01). An intensity of average competition index as dead bamboo > living bamboo > new bamboo. This indicated that the growth condition had an important effect on bamboo regeneration.
Acer tutcheri is a typical native tree species in the Pearl River Delta region. Studies on the characteristics of the natural community is useful to provide some scientific proofs for the reasonable community construction of A. tutcheri scenic forest in this district. Sampling plots were set up in the A. tutcheri natural communities of Guangdong Nanling National Nature Reserve, Heishiding Nature Reserve and Shenzhen Dapeng Peninsula National Geopark Qiniangshan. Comparative analyses of their species composition, species community structure, species diversity and interspecific association were conducted. The results show that the number of species in three regions was Nanling >Heishiding >Qiniangshan. The average tree height of A. tutcheri in Heishiding is 15.1 m, and showed the best red leaf landscape effect than the other two sites. Tree height of A. tutcheri, lower than 2.0 m is 52% of all trees and there is relatively abundant small size trees in Nanling. The diameter class structure of Nanling showed the pattern with multi peaks, while Heishiding and Qiniangshan showed inverted "J" type distribution pattern. The 105 species pair correlation of 15 species of woody plants in three regions showed a significant positive correlation. These results reflect the relatively high diversity of Acer tutcheri community in Nanling. A. tutcheri community environmental adaptability and landscape effect is relatively better in Heishiding. A. tutcheri seedlings is relatively rare in Qiniangshan. Therefore, the construction of the transformation of A. tutcheri scenic forest in the Pearl River Delta should consider the seedling plantation and the tree arrangement, with the reference of A. tutcheri communities in Nanling and Heishiding, in order to improve A. tutcheri scenic forest species diversity and landscape effect.
With storage irrigation and normal diversion of water from south to north, water level fluctuations in Hongze Lake have had a profound impact on soil moisture and the growth of wetland vegetation. To provide a theoretical basis for water management along with scientific management and protection of the poplar forest in Hongze Lake Wetland, spatial and temporal variations of soil moisture on a wetland system of poplar and their correlation with meteorological factors were analyzed using the system of eddy covariance and soil moisture monitoring. Results showed that over a year in the Hongze Lake Wetland the change of soil moisture in the poplar plantation could be divided into a stable period (October-February: 31.36%-36.07%), a consuming period (March-April: 36.64%-37.46%), an accumulating period (May-July: 39.22%-53.92%), and a subsiding period (August-September: 40.38%-32.92%). The diurnal variation of soil moisture in spring, summer, and winter exhibited mono-peak curves; whereas, two-peak curves occurred in autumn. Also, soil moisture increased with an increasing soil depth (0-40 cm). In addition, soil moisture in the poplar plantation was highly significant (P < 0.01) and positively correlated with daily precipitation (r = 0.203-0.378), daily mean air temperature (r = 0.462-0.549), daily average relative humidity (r = 0.397-0.510), and daily mean soil temperature (r = 0.549-0.862); it was also highly significant (P < 0.01) and negatively correlated with daily mean sensible heat flux (r = -0.238--0.482) and average wind speed (r = -0.293--0.430). Among these variables, the most obvious effect on soil moisture was with daily mean soil temperature (contributing 10.73%-57.97% to soil moisture) and daily average relative humidity (contributing 18.62%-25.12%. Based on the above analysis, an advice when we plant poplar using the method of ditching and ridging is put forward.
To determine characteristics of rainfall and runoff with differing initial silvicultural prescriptions for a low efficiency Pinus massoniana forest, five adjacent runoff areas of Gaoxian County were studied. Five silvicultural prescriptions: Cinnamomum camphora planted under a P. massoniana forest (Ⅱ), C. camphora planted after clear cutting P. massoniana (Ⅲ, Ⅳ), C. camphora planted the second year after clear cutting P. massoniana (Ⅴ), and a P. massoniana forest as a control (Ⅰ) were used to analyze rainfall, different modes of flow, and the relationship between them using a correlation analysis. Results showed that total rainfall each year was mostly concentrated from June to September. In a 24 h period, the maximum rainfall was 93.6 mm, and the minimum runoff rainfall was 6.9 mm. The maximum runoff volume was 3.002 0 m3, and the minimum was 0.006 4 m3. For the five runoff plots, with light rain almost no surface runoff was found with the average single runoff ranked in the order of Ⅲ >Ⅳ >Ⅴ >Ⅱ >Ⅰ. This was consistent with the human disturbance intensity. Compared to the second half of 2012, the runoff coefficient in the second half of 2014 for runoff areas Ⅰ-Ⅴ decreased 29.36%, 26.30%, 47.37%, 41.54%, 43.97%. The correlation analysis for rainfall and runoff showed that the correlation coefficient between them were more than 0.905. Thus, the result of the three clear cut runoff areas on surface runoff was better at the initial stage of reconstruction.
To provide a scientific basis for sustainable management of plantations on the Leizhou Peninsula, changes of soil organic C, total N, total P, and total K in three different kinds of plantations were explored. Three sample plots were set in Eucalyptus urophylla × Eucalyptus grandis, Eucalyptus camaldulensis, and Pinus elliottii × Pinus caribaea plantations with the five-point sampling method employed for stratification and sampling. Concentrations of C, N, P, and K and their stoichiometric characteristics were analyzed in different plantations and soil depths. Results showed that among the three kinds of plantations, soil organic C and total N content at depths of 0-60 cm were not significantly different. Soil total P of E. camaldulensis plantation was significantly lower (P < 0.05) than P. elliottii × P. caribaea plantation, but was not significantly different between E. urophylla × E. grandis and P. elliottii × P. caribaea plantation. The content of soil total K was in the order of Pinus elliottii × P. caribaea > Eucalyptus camaldulensis > E. urophylla × E. grandis with the soil C:K, N:K, and P:K ratios significantly lower (P < 0.05) in Pinus elliottii × Pinus than Eucalyptus plantations. Soil organic C and total N in the three different plantations decreased significantly (P < 0.05) with an increase of soil depth. The C:P, C:K, N:P, and N:K ratios decreased significantly with an increase of soil depth (P < 0.05), but C:N and P:K showed no consistent pattern. For the three kinds of artificial forests in the 0-60 cm depth, soil C:P was less than 200.00, and N:P, which was below the national average, demonstrated that plant growth was limited by N. Correlation analyses also showed that total N had a significant positive correlation with soil organic C (r = 0.925, P < 0.01), but was not significantly different (P>0.05) from total P (r = 0.253) and K (r = -0.016). In conclusion, stand growth in the test area was limited by N and balanced fertilization was needed to prevent soil degradation in these fast-growing pine and eucalypt plantations.
To evaluate the effects of biochars pyrolyzed from different feedstocks (bamboo, maize straw, and peels of Carya cathayensis) on the soil properties, acidity, microbial abundance, and soil enzyme activity in an acidic soil collected from a bamboo (Phyllostachys violascens) plantation in Lin'an, Zhejiang Province, a 90-day pot experiment was conducted in a completely randomized design with treatments of above three biochars and a non-amended control in three replicates. The biochars were added to the soil at a rate of 2% (weight of biochar to soil) with ryegrasses being planted during the experiment. Fungal 18S rRNA and bacterial 16S rRNA gene abundances were assessed via quantitative real-time (qRT) polymerase chain reaction (PCR). Significant differences between treatment means were tested with one-way analysis of variance (ANOVA) followed by Duncan's test at P < 0.05. Results indicated that biochars derived from maize and peels of C. cathayensis significantly (P < 0.05) increased the biomass of ryegrass, soil organic carbon, total nitrogen, and pH, but decreased (P < 0.05) exchangeable H+ and exchangeable Al3+. Also bamboo biochar significantly increased (P < 0.05) soil organic carbon and decreased (P < 0.05) exchangeable H+. The qRT-PCR showed that compared with the control only additions of maize biochar significantly increased (P < 0.05) fungal community abundance by 53%; whereas, peels of Carya cathayensis biochar and bamboo biochar significantly increased (P < 0.05) bacterial community abundance by 71% (C. cathayensis biochar) and 66% (bamboo biochar). In comparison with maize straw biochar and bamboo biochar, the addition of peels of C. cathayensis biochar resulted in higher (P < 0.05) enzymatic activities of dehydrogenase, β-glucosidase, β-D-cellobiosidase, and acid phosphatase. Enhancement of ryegrass growth was noted with peels of C. cathayensis biochar and maize straw biochar. In summary, results indicated that biochars pyrolyzed from maize straw and peels of C. cathayensis showed better amelioration effects in terms of chemical and biological ability than bamboo biochar.
The objective of this research was to screen out appropriate forest and medicinal plant agroforestry patterns of Chinese fir (Cunninghamia lanceolata) with medicinal plants and determine the effect on soil physical and chemical properties so as to promote the reconstruction of an ecological forest and healthy development of an understory-forest economy. A completely randomized block experimental design was used to establish eight agroforestry patterns including [SD (Chinese fir (Cf) + Nauclea officinalis), SS (Cf + Tutcheria championi), SM (Cf + Ilex asprella), SC (Cf + Alpinia katsumadai), SL (Cf + Callicarpa nudiflora), SJ (Cf + Camellia nitidissima), SH (Cf + Taxus chinensis), and ST (Cf + Aquilaria sinensis)] and a control of Chinese fir with six physical and nine chemical indexes at 0-20 cm and 20-40 cm soil layers having three replications. The grey correlation method was used to evaluate the improvement effect. Results showed that eight patterns significantly (P < 0.05) improved the surface soil physical properties and nutrient content. SD had the best improvement with higher soil quality water content (50.5%), field water holding capacity (75.1%), and total capillary porosity (36.9%) than the control; whereas, non-capillary porosity in SS was 1.1 times the control. The minimum soil bulk density was reduced 22.3% in SM compared to the control. The highest contents of soil organic matter (41.8%), available N (35.0%), available K (108.1%), total K (35.0%), and total P (108.1%) compared to the control all appeared in SC with soil available P highest in SL. Soil total N reached maximum in SD with cation exchange capacity in SD (32.1%) and SJ (52.0%) higher than the control. The rank of improvement on soil physical and chemical properties for the eight patterns and the control was as SC >SD >SM >SH >SS >SL >ST >SJ >control. So Chinese fir and medicinal plant agroforestry patterns improved soil quality with the best pattern being SC (Alpinia katsumadai with Chinese fir) which was suitable for popularization and application.
To confirm the spatial distribution and seasonal dynamics of fine roots in the non-timber forest products breeding and cultivation practice base for Castanea mollissima (chestnut) of Beijing Forestry University in Qianxi, Hebei Province, the monthly dynamics and spatial distribution characteristics of fine root length density and dry weight density in a six-year-old chestnut plantation for the 0-20, 20-40, and 40-60 cm soil layers were studied using the soil coring method. Soil cores with a diameter of 8 cm were taken each month during the growing period (from April to October) about 50 and 100 cm away from the chestnut tree stem. Results showed that the fine root length density with a monthly average value of 1 274.9 m·m-3 had two growth peaks. Compared to the previous month, June and October both had significant difference (P < 0.05), which increased 203.0 m·m-3 and 524.6 m·m-3 separately. The fine root dry weight density had a monthly average value of 184.7 g·m-3 and two growing periods from April to June and from September to October. The fine root dry weight density in October was 39.5 g·m-3 higher compared to that in September (P < 0.05). The value of the fine root length density and dry weight density reached a maximum and changed with the seasons most noticeably in the vertical direction of the 20-40 cm soil layer (P < 0.05). Also, the fine root length density and dry weight density in the horizontal direction about 100 cm were greater than those about 50 cm (P < 0.05). This study indicated that spatial distribution and seasonal dynamics of fine roots likely resulted from spatial soil properties and the growth rule of C. mollissima.
To grasp the growth process of Pinus tabulaeformis in Beijing and to establish general and compatible models, stand basal area and volume growth models with dummy variables of thinned and unthinned stands were established. Then from the perspective of compatibility, simultaneous equations with error variables were established for stand basal area and volume. These were compared to simultaneous equations with error variables of the traditional growth model with no dummy variable. Results after inspection showed prediction accuracies of stand basal area and volume were over 92% in the traditional simultaneous equations with error variables. Prediction accuracies of P. tabulaeformis for stand basal area reached 0.921 5 with coefficients of determination as high as 0.900 1; whereas, prediction accuracies of stand volume reached 0.928 3 with coefficients of determination of 0.912 3. However, in simultaneous equations with error variables of introduced dummy variables, the prediction accuracies and coefficients of determination of models were slightly higher with over 93%. Prediction accuracy of stand basal area was over 0.939 8 with coefficients of determination reaching 0.927 9. Prediction accuracy of stand volume was over 0.930 0 with coefficients of determination as high as 0.932 8. Thus, to improve prediction accuracies, models using dummy variables were reasonable as the form was relatively simple, easy to apply, made forecast results of stand basal area and volume predictions consistent, considered the effect of thinning measures on stand growth, and achieved the purpose of stand growth and yield model integrative research, thereby offering a reliable basis for forest management.
To explore chlorophyll fluorescence characteristics of a Phyllostachys edulis blade during its fast growth period (early, middle, and late phases), parameters concerning chlorophyll fluorescence of a Ph. edulis blade were measured using PAM-2100 chlorophyll fluorescence spectrometer during its fast growth period of the Bamboo Physiological and Ecological Monitoring Station of Zhejiang A & F University, also comprehensive evaluation of its fluorescence characteristics was then conducted. The results showed that the actual photochemical quantum yield of Photosystem Ⅱ (PS-Ⅱ), the maximal photochemical efficiency of PS-Ⅱ (Fv/Fm), and the potential PS-Ⅱ activity for same-aged Ph. edulis samples had significant differences within different stages of the rapid growth period (P < 0.05) going from a lower level to a higher level for the early phase, the middle phase, and the latter phase. Variation in the Fv/Fm ratio was 0.672-0.773 and in the Fv /Fo ratio was 2.068-3.231. During the fast grwoth period, the value of Non-photochemical Quenching(qNP) in the order: middle phase < late phase < early phase. The qNP value also showed strong daily variation during different phases of the fast growth period. Chlorophyll fluorescence parameters of bamboo blade show significant changes during its fast growth period. Thus, as indicated by the comprehensive comparison, photosynthesis of the Ph. edulis blade showed an increasing tendency during its rapid growth.
Dust removal ability is an important factor in the choice of green tree species when environmental pollution of a city is becoming serious. To reduce particulate matter in the air, differences among six tree species commonly cultivated (Magnolia grandiflora, Cinnamomum camphora, Viburnum odoratissimum, Castanopsis sclerophylla, Schima superba, and Koelreuteria bipinnata) in Hangzhou City were studied. At the 5th day and 10th day after rain in summer, the dust capturing capacity of tree leaves was measured by immersion weighing method and chlorophyll-fluorescence indexes of tree leaves were mearsured using PAM-2100, as well as the concentration of particulate matter(PM2.5, PM10), and the air negative ions under these trees were surveyed by air quality minitoring instruments. Results showed that leaves of these six urban trees species captured dust from the air effectively with significant differences among the six tree species (P < 0.05). Leaves of S. superba and M. grandiflora compared to the other tree species absorbed dust most effectively with highly significant differences(P < 0.01). The amount of dust absorption per unit leaf area for the trees 10 days after rain was increased significantly(P < 0.01) than that of 5 days after rain. For most tree species, relative chlorophyll content, Fv/Fm (the ratio of variable fluorescence from dark-adapted material and maximum fluorescence signal from dark-adapted material), and yield showed a decrease with an increase of dust residence time on leaf surfaces. Thus, the photosynthetic characteristics of these six tree species were inhibited with PM stress. Almost all of the trees can reduce the particulate matter, and release the negative air irons. According our results, the trees with high dust removal capability and small effect on photosynthetic characteristics, such as Magnolia grandiflora and Cinnamomum camphora, can be selected as the preferred tree species for urban greening.
Different shading treatments (full light, 55% shading, and 90% shading) on the morphology, physiological characteristics, and photosynthetic characteristics of four Rhododendron cultivars, ('Liuqiu Hong', 'Yanzhi Mi', 'Zi E', and 'Zhuangyuan Hong') were studied. Results showed significant differences between shading treatments and full illumination (P < 0.05). With an increasing degree of shade, the Rhododendron plant height, leaf length, leaf width, and chlorophyll content increased significantly(P < 0.05), but leaf thickness, chlorophyll a/b, specific leaf weight per unit area, and water content decreased significantly (P < 0.05). The light saturation point for the four cultivars was in the range of 800.0-1 200.0 μmol·m-2·s-1, the light compensation was 10.0-25.0 μmol·m-2·s-1, and the dark respiration rate was 0.3-0.9 μmol·m-2·s-1. Comparing shade tolerance for these cultivars of Rhododendron, the membership functions order from strong to weak was 'Zhuangyuan Hong' > 'Yanzhi Mi' > 'Zi E' > 'Liuqiu Hong'. Overall, shade tolerance of Rhododendron was favorable with light adaptation for these different culitivars of Rhododendron variable.
To study the influence of flowering dynamics and dichogamy characteristics on sexual reproduction of Manglietia glauca in the introduced area of Pingxiang, Guangxi, three stands of M. glauca were selected as the study area. Based on the flowering phenology and flowering dynamics, pollen and stigma viability in different flowering stages were tested. Results showed that (1) M. glauca started to bloom in late January, reached full bloom in late March, and lasted to early May. M. glauca occasionally bloomed twice a year with the second flowering phase lasting from the middle of October to early December. (2)Due to temperature difference in different flowering stage, the duration of each phase in flowering process was different, appeared different two-time flower opening and closure pattern. (3) Manglietia glauca showed dichogamy and protogyny in its flowering process with the pistil located in the upper stamens to avoid the possibility of self-pollination that could occur both in time and space. M. glauca also bloomed for centralized synchronization in single plant level. When flower pollen was released during the first round of flowering, pistil viability in the second round of flowering was stronger. The time of strongest expression for both male and female sexuality overlapped from 1-6 h, and this provided opportunity for successful pollination. (4) After artificial xenogamy, geitonogamy, and self-pollination, the fruits and seeds could be set with the pollination success rate of xenogamy being highest (68%). The pollination success rate was lowest (40%) in the initial flowering period with the lowest temperatures, but the pollination success rate was higher in the transition period (65%) and bloom stage (68%) with higher temperatures. The high pollination success rate of xenogamy indicated that M. glauca had priority for out-crossing but was self-compatible to some degree, and the pollination success rate of the initial flowering period, the transition period, and the bloom stage indicated that a high temperature was more beneficial to fertilization and embryo development than a low temperature.
To determine the molecular mechanism of Lycium ruthenicum, a perennial shrub species that has attracted great interest in recent years due to its nutritional value and abiotic stress resistance, with its high salt tolerance capability, a potential outward-rectifying potassium channel gene was cloned based on a transcriptome sequencing database analysis. Analyses also included real time (RT)-polymerase chain reaction (PCR), a homology comparison analysis, and a gene expression analysis. Results of the RT-PCR indicated that the length of this potential L. ruthenicum SKOR (LrSKOR) gene was 2 448 bp encoding 815 amino acids. The homology comparison analysis showed that the SKOR gene shared more than a 60% amino acid sequence similarity with reported plants, such as Arabidopsis thaliana, and had over 90% similarity with other Solanaceae plants. Gene expression analysis with RT-PCR showed that the LrSKOR gene was strongly induced by NaHCO3 stress and weakly induced by NaCl stress; its expression level with NaHCO3 stress was 6.81 times higher than NaCl stress and 23.79 times higher than the control. Thus, expression of LrSKOR, regulated by both saline and saline-alkali stress, with pH imposed a strong influence on its expression. The results could help in LrSKOR gene function prediction as well as lay a foundation for further research of high salinity stress response in L. ruthenicum.
To clarify allelopathic potential and the preliminary mechanism of Triticum sestivum (wheat) on Aegilops tauschii, the effect of concentrations of T. sestivum extracts from stems, leaves, and roots on seed germination and seedling growth of A. tauschii were studied using Petri dish bioassays. Effects were based on physiological and ecological indexes, such as seed germination rate, seedling height, root length, superoxide dismutase (SOD) activity, malondialdehyde (MDA) content and other physiological and ecological index. Results showed that the aqueous extract increased membrane penetrability of A. tauschii, and enlarged the relative electrical conductivity, but decreased the chlorophyll mass fraction, reaching significance at 100 g·L-1 (P < 0.05). Also, water extracts increased SOD activities as well as proline and MDA content. At low concentrations (5 g·L-1), MDA increase was not significant (P>0.05), but with higher concentrations, MDA increased significantly (P < 0.05). According to the inhibition synthesis effect, the allelopathic inhibition of wheat stems and leaves was stronger than roots in the range of 25-100 g·L-1. Thus, seed germination along with seedling and root growth of A. tauschii were promoted at low concentrations of T. sestivum extracts and inhibited at high concentrations.
To provide a basis for introduction to appropriate regions and to further improve genetic traits for Dalbergia cochinchinensis, seed morphology from various provenances and different germination rates in various regions were studied. Morphological parameters, including seed length, seed width, seed thickness and 1 000-seed weight, were measured and a germination test (RCB design with 50-seed plot and 4 replications) was conducted in four districts (Guangzhou, Zhangzhou, Yangjiang, and Ledong) with 25 families of D. cochinchinensis seeds collected from 10 provenances in Thailand, Cambodia, and China. ANOVA analysis, correlation analysis, and cluster analysis were conducted with different traits. Results showed that seed length ranged from 6.09 mm to 7.19 mm, seed width ranged from 3.84 mm to 4.28 mm, seed thickness ranged from 0.98 mm to 1.19 mm, and the 1 000-seed weight ranged from 15.80 g to 33.76 g. The highest average germination rate was in Yangjiang with seeds from 'Prachin Buri' having the highest average germination rate (up to 83%) of the four regions. Highly significant differences among the provenances and the sowing locations (P < 0.01) were found with the highest seed germination rate by provenance and planting location being 'Kampong Cham' in Guangzhou (79%), 'Pursat' in Zhangzhou (92%), 'Prachin Buri' in Yangjiang (90%), and 'Prachin Buri' in Ledong (87%). No correlation between the 1 000-seed weight and germination rate for the four regions was found (P>0.05). In both Yangjiang and Ledong habitats, variation in germination rates of seeds was similar. A cluster analysis indicated that the seeds of D. cochinchinensis could be divided into three categories. Thus, morphology and seed germination could be used as a basis for introduction and selection with D. cochinchinensis seeds from 'Prachin Buri' performing the best overall from this study.
Ips subelongatus, a native bark beetle categorized as a dangerous forest pest in China having caused huge losses to larch forests, and ophiostomatoid fungi, important plant pathogens with strong pathogenicity which numerous studies have shown to be the main group of fungi associated with bark beetles, have played a key role in the process of beetle damage, sometimes killing tree hosts. This study on specific and rapid detection of pathogens, a prerequisite for clarifying the distribution of diseases and assessing their hazards, was designed to overcome the shortcomings of traditional tissue isolation, which normally influenced by a variety of anthropological factors. Two pathogens Ophiostoma olgensis and Endoconidiophora fujiensis were specifically detected by polymerase chain reaction (PCR). Internal transcribed spacer (ITS) sequences were used as a target to design species specific (SS-) PCR primers through comparison of 14 sibling species from the genera Endoconidiophora and Ophiostoma. Results showed that two pairs of primers (OK1/OK2 and CFU1/CFU2), which could amplify specific sequences from the fungal flora and host tissues, were screened out. Primer pairs OK1/OK2 and CFU1/CFU2 specifically amplified a clear and bright band of 248 bp from O. olgensis and 251 bp from E. fujiensis. Thus, O. olgensis and E. fujiensis were detected by the SS-PCR from phloem tissues in which the two fungi had been previously isolated.
Atmospheric pollution is becoming serious, and PM2.5 pollution has become of increasing public concern because of its importance to human health. To determine the effect of landscape pattern on the PM2.5 pollution in Zhejiang Province, this study was conducted based on the PM2.5 concentration of 47 monitoring sites and their land use pattern matrices. Five landscape metrics were tested, landscape composition metric(PLAND), landscape configureuration metric(ED, PD, SHEI, and CONTAGE). Also, The influence of landscape pattern on PM2.5 were tested using a correlation analysis and regression analysis. Results showed that: (1) among the five landscape matrices, PLAND and ED had obvious effects on PM2.5. The resi_PLAND_5 significant correlate with PM2.5(P = 0.633). (2)Resi_PLAND has played the most significant impact on PM2.5 concentration in the different regression models. The composition and configureuration of construction land(resi_ED, resi_PD, comm_PD and comm_PLAND) also appeared in the seasonal regression; water, road, and forest also had the influence on PM2.5 concentration in different seasons. In conclusion, land use type and landscape pattern matrices are important factors affecting PM2.5 concentration with spatial and temporal variability from these results providing a theoretical and practical basis for land use planning and PM2.5 pollution control.
The research aimed at making use of the new research methods to conduct more convenient and in-depth study of tourists' tourism image perception of the wetland park tourism destinations and provide a useful reference for the sustainable development of national urban wetland park tourism. It used the web-based text analysis method and collected relevant reviews and travelogues from search engines and tourism websites including Baidu, Dianping, and Ctrip as samples, and used ROST Content Mining software to analyze tourists' tourism image perception of Mirror Lake National Urban Wetland Park from the following five perspectives, namely, the scenic environment, activities, tourist attractions, service facilities and cultural background. The results indicated that visitors to the Mirror Lake National Urban Wetland Park had overall good emotional attitudes towards the park; they had comparatively high evaluation of the overall impression of the scenic area and scenic environment; they were rather satisfied with the leisure and entertainment activities in the scenic area. However, they lacked deep understanding of wetland park background culture and held certain negative attitudes towards the scenic infrastructure and services. Based on the research findings, the paper pointed out that the profound tourism development of urban wetland parks should be focused on maintaining the feature advantages, improving facilities and services, and strengthening cultural publicity.
To acknowledge the influence of nitrogen (N)-fixing plants as life forms as well as value of their ecotypic, economic, and medicinal parts in Phyllostachys edulis (moso bamboo) stands, N-fixing plants were surveyed in their main distribution areas of Zhejiang and Fujian Provinces using the method of field surveys. Relating research results of N-fixing plants not surveyed in Ph. edulis stands were also refered. Results showed that altogether there were 41 species in 23 genera of four families. Among them, Leguminosae accounted for 85.37% with Papillionaceae having 75.61% and non-Leguminosae, such as Elaeagnaceae, Euphorbiaceae, and Myricaceae accounted less. Plants were comprised of 20 shrub species, seven tree species, five herbaceous species, and nine vine species along with three ecotypic types of xerophyte, mesophyte, and hygrophyte, mainly mesophyte. The investigated 41 species all had medicinal value. In addition, 23 species had edible value, 10 species could be used as feed, and seven species could be used for fertilizer. According to their value as a medicine, the part of the plant in these N-fixing plants species under Ph. edulis stands was in general ranked as root > stem > whole plant > leaf > flower > fruit > seed. This research could provide a theoretical basis for the establishment of an eco-efficient compound management model in Ph. edulis stands.
Glucosinolates are nitrogen-and sulfur-containing secondary metabolites that mainly found in the Brassicaceae plants. In recent years, the study which involves the biosynthesis of glucosinolates, especially its relationship with sulfur has made some new progress. The research attempted to review the research progresses on the sources of reduced sulfur and active sulfate in the formation of the core glucosinolate structure. The paper also discussed the link between primary sulfur metabolites including Cys, GSH, PAPS and glucosinolate biosynthesis, as well as the relevant research in the future, so as to lay the foundation for the further study.
To research the influence of tebufenozide and chlorbenzuron on the physiological mechanism of Apriona swainsoni (Hope), A. swainsoni larvae were fed with sawdust treated by chlorbenzuron (T1) and tebufenozide (T2). These were then sampled to determine enzymatic activity of catalase (CAT), superoxide dismutase (SOD), glutathione S transferases (GSTs), and carboxylesterase (CarE) in larvae at intervals of 12 h to 72 h in succession. Results showed that after treatment with chlorbenzuron, the enzymatic activity of CAT increased first and then decreased 24 h later. Enzymatic activity of SOD maintained a high level. Also, after treatment by tebufenozide, the enzymatic activity of CAT decreased first with enzymatic activity of SOD being higher than the control. After treatment by two types of the pesticides, enzymatic activity of GSTs was higher than the control with no differences of CarE activity with the control. Therefore, enzymatic activity of GSTs in A. swainsoni was assumed to be associated with resistance generated in the larva and was likely to be a resistance marker of the larvae.
To obtain efficient termite bait having long-term use without mildew, this experiment compared the feeding preferences of Coptotermes formosanus for cellulose bait, pine-cellulose bait, eucalyptus bark-cellulose bait and pine. The effects of cellulose bait, pine-cellulose bait, and eucalyptus bark-cellulose bait, all treated for one month outdoors, as well as the above three untreated cellulose baits, against C. formosanus with chlorfenapyr were determined. From March to October in 2015, 55 cellulose baits replications were buried around the landscape and buildings to observe the attractant effects on termites every month. Results of the laboratory experiment indicated that food consumption of C. formosanus for cellulose bait was significantly greater than pine and pine-cellulose bait (P < 0.05), and no significant differences were noted with eucalyptus bark-cellulose bait (P>0.05). After one month, the cellulose bait, pine-cellulose bait and eucalyptus bark-cellulose baits all with chlorfenapyr buried around the landscapes and buildings had no effect on toxicity of C. formosanus. During the eight months of the field experiment, no mildew was found on the cellulose bait, and the cellulose bait showed considerable attractant effects on termites in Reticulitermes flaviceps, Odontotermes formosanus, and Macrotermes barneyi. Thus, cellulose was more palatable to termites, had long-term resistance to mildew, and had efficient attraction to several genera of termites over a long time period making it very suitable for long-term control of termites.
To confirm the best micrografting method and improve the propagation coefficient of Torreya grandis ‘Merrillii’, seedlings which were not lignified and sprigs with no T. grandis ‘Merrillii’ terminal bud were prepared for an experiment to study dynamic germination changes, survival rates, and growth conditions. Different micrografting techniques with scions having 2, 4, and 6 pieces of leaves as well as scions with and without terminal buds were used. The micrografting methods design with treatments of cleft grafting, drill grafting and side grafting and 3 replications. Every treatment was randomly selected 30 seedlings to statistics and analyze. Results showed that cleft grafting of T. grandis ‘Merrillii’ seedlings had more advantages. The scions germinated after being grafted 15 d, and the grafting survival rate was high (89.7%) which was significant difference under the LSD significance test method with the other two micrografting methods at P=0.05. Also, the cleft grafted seedlings which growth of new shoots was greater, but the coarseness of growth, the number of new branches and stubble, and the number of new crops and leaves showed no significance differences at P=0.05. This study showed that micrografting seedlings of scions without terminal buds were more likely to survive in the short term, but in the long run, cleft grafting with scions removed on terminal buds and with 4 to 6 pieces of leaves was the most suitable for growth of T. grandis ‘Merrillii’.