CO2,N2O and CH4 fluxes from Karst rocky desertification areas in central Guizhou were measured monthly by using static chamber-GC method from June 2006 to May 2007 to investigate the characteristics of seasonal change of greenhouse gas fluxes from soil in Karst region in South China.The results indicate that the soils are the sources of CO2 and N2O,but the sink of CH4.CO2 fluxes change from 450.8±50.8 to 1281.3±214.7 mg·m2·h-1,with higher fluxes in summer and autumn,but lower fluxes in spring and winter.N2O fluxes vary from-25.4±4.1 to 105.8±31.2μg·m-2·h-1,with the highest fluxes in summer.The soils absorb N2O in the air in September,November and December.CH4 fluxes show no significant changes with the seasons,and they vary from-0.27±0.18 to 0.81±0.26 mg·m-2·h-1.The climate conditions have no obvious effects on the fluxes of CO2 and CH4.The effects of soil water on N2O fluxes vary with seasons.The correlation analysis shows that there is significant correlation between soil nitrate content and N2O/CH4 fluxes,suggesting nitrate content in soil is the primary driven factor affecting the seasonal change of N2O and CH4 fluxes.
Very high cell densities of Cylindrospermopsis raciborskii were detected in low salinity prawn ponds for Litopenaeus vannamei in Pearl River Delta areas,Guangdong Province,South China from 2002 to 2003.More than 20 prawn ponds were surveyed,and the density of C.raciborskii reached to 7.74×107 filaments·L-1,with an average dominance of 47%.The water temperature in the prawn ponds was 30.3℃;pH is 8.6;salinity was 1.4‰; transparency was 19 cm and the chemical oxygen demand(COD) was 24.3 mg·L-1.It is obvious that C.raciborskii bloom occurs in the environmental condition of high water temperature,high value ofpH,high level of COD and low salinity;moreover,stirring the water in the ponds facilitates the forming of C.raciborskii bloom.In general,the bloom occurs in the middle or late term of water eutrophication in the prawn ponds. C.raciborskii cells can restrain the growth of other algae and microbes in the prawn ponds;some other algal species such as Dactylococcopsis acicularis and Cyclotella sp.can dominate with C.raciborskii.The spiral C.raciborskii is the dominant algal species in the low salinity prawn ponds in Pearl River Delta area,South China.
We researched the decomposition of leaves of Syzygium jambos and Michelia alba allocated into coarse and fine mesh bags in terrestrial habitat(210 d) and pond(60 d) at the Changgangshan Nature Reserve,Guangzhou.The breakdown rates of S.jambos in coarse and fine mesh bags were 0.003 318d-1 and 0.003728d-1,while those of M.alba litter were 0.009238d-1 and 0.004379d-1,respectively,in terrestrial environment.In lentic environment,the breakdown rates of S.jambos in coarse and fine mesh bags were 0.009 536d-1 and 0.012 591d-1,while those of M.alba litter were 0.017 949d-1 and 0.020 759d-1, respectively,indicating that the leaf litter decomposition rates of the two species were lower in terrestrial habitat than in lentic environment.Furthermore,the decomposition rates of S.jambos were lower than those of M.alba both in terrestrial habitat and in lentic environment,mainly due to its high content of polyphenols which can inhibit the growth of microbes.
Three native tree species Cinnamomum camphora,Gordonia axillaris and Syzygium hance were selected and sprayed with cuprum(Cu) and plumbum(Pb) solutions of different concentrations to examine their physio-ecological response to Cu and Pb stress.The concentrations for Cu were 0 mg·L-1,50 mg·L-1,150 mg·L-1 and 250 mg·L-1;while the concentrations for Pb were 0 mg·L-1,10 mg·L-1,20 mg·L-1 and 30 mg·L-1.At the end of cultivation period,some parameters including tree height, biomass of roots,stems,and leaves as well as total biomass were measured;besides,biological membrane permeability and SOD activities of leaves were surveyed.The results are as follows.(1) The inhibition of growth of three native tree species becomes much more significant as the concentrations of solutions increase.S.hancei grows the best as compared to other species.(2) The biological membrane permeability of tree leaves is increased with the increasing of solution concentrations,indicating the damage caused by the Cu and Pb becomes more serious with the increasing of solution concentrations.When Cu concentrations is 250 mg·L-1,the leaf membrane of C.camphora is damaged the most as compared with other tree species,while the leaf membrane of G.axillaris is damaged the most at 30 mg·L-1 Pb.(3) Under Cu stress,SOD activity of leaves is rised at first then decreased as the concentration increases except for G.axillaris,SOD activity of which is increased with the increasing of Cu concentrations.(4) Under Pb stress,as the concentration rises,SOD activity of leaves is declined with the exception of S.hancei, leaf SOD activity of which appears to increase in the end of experiment.
Growth parameters of field-grown seedlings of 19 Magnolia officinalis provenances were successively measured and comprehensively analyzed in this study.The results show that there are extremely significant difference among provenances in seedling height,basal diameter,root dry weight,root/shoot ratio and water content.The growth patterns of height and basal diameter can be fitted by "S" curves and can be simulated with Logistic equations.Prosperous phases for seedling growth are from July to September,during which 77.7% of seedling height and 50.0% of basal diameter in the whole one year are achieved. Two-way geographic variation in latitude and longitude is observed in the seedling stage.By analyzing the correlation of biomass with seedling height and basal diameter,the authors find that seedling height shows a significantly positive correlation with shoot dry weight and shoot fresh weight,while biomass and basal diameter are significantly correlative.Five superior provenances, including Daoxian,Jianghua,Anhua,Rongshui and Qianshan are selected according to cluster analysis and their growth performance.
A laboratory bioassay was carried out on two azadirachtin-based insecticides and their mixtures with entomopathogenous fungi against Lepidoteron pests on mangroves.The results showed that Azadirachtin-matrine 1% EC and Azadirachtin 0.3% EC and their mixtures with one strain of Metarhizium anisopliae(Ma) and one strain of Beauveria bassiana(Bb) were very virulent to mangroves insect pests including Homona coffeari,Oligochroa cantoonella and Orgyia postica,and about 78.6～100% of mortality was caused within one week with a diluted solution of 500 to 1000 times of single insecticide or a dilution of 700 times of insecticides mixed with a concentration of 1×106 spores·mL-1 of Ma&Bb.The mixture of both Azadirachtin-based insecticides and Ma&Bb was more effective to kill insects than single agent.The mixture of both insecticides at a dilution of 700 times and Ma&Bb at a concentration of 1×106 spores·mL-1 caused 100% of mortality to Homona coffeari and 93.3% of mortality to Orgyia postica 3 days after treatment.The application of the mixture of both insecticides at a dilution of 500 times and Ma&Bb at a concentration of 1×106 spores·mL-1 was successfully to control Homona coffeari on Aegiceras corniculatum in the field,with a mortality of 65.4～100%.It is suggested that the mixture can be extended largely to control Lepidopteron pests on mangroves due to its systemic effect, high virulence,low toxicity and environmental safety.
Jiuduansha is an important new tidal fiat in the Yangtze River Estuary.As one of main typical canopies over Jiudnansha tidal flat,vegetation is an important indicator factor which can show the variety of ecological environment.Based on the Landsat satellite remaote sensing data from 1987 to 2008,the authors analyze the spatial and temporal dynamic variations of vegetation communities in Jiuduansha tidal flat by using ArcGIS.The results indicate that Jiuduansha vegetation is in the natural succession stage and Scirpus mariqueter is the primary vegetation during 1980s-1990s.As the tidal fiat increases,the vegetations grow up quickly.Since 1997,Phragmites australis and Spartina alterniflora have been artificially planted.The percentage of Phragmites australis,Spartina alterniflora,Scirpus mariqueter was 39.35%,31.47%,29.17% respectively in 2008.The alien species Spartina alterniflora becomes the dominant species and the planted area for Scirpus mariqueter is decreased..
The survey on bird resources and its G-F index of Golden Budda Mountain belonging to National Level Nature Protection Area was investigated using sample-point method during July to August in 2008.The results showed that there were 115 species belonging to 33 families and l0 orders,in which 92 species(80%) were Passeriformes and 5 species(4.35%) were Galliformes.There were 5 species belonging to Ⅱ level of National Conservation Bird and 4 species embodied in"Convention on International Trade in Endangered Species of Wild Fauna Flora".81 species(70.43%) were the birds of the Oriental realm;26 species(22.61%) were Palaearctic,and 8 species(6.96%) were widespread species.There were 82 species(71.30%) of resident birds,27 species(23.48%) of summer migrant,4 species(3.48%) of winter migrant,and 2 species(1.74%) of passage birds. The G-F index of Golden Budda Mountain is 0.7573,with the F index of 17.1257,and G index of 4.1561.
Five factors of amplification system,such as concentration of Mg2+,dNTPs,primers,Taq DNA polymerase and DNA template were investigated to optimize the ISSR-PCR reaction system of H.inermis through orthogonal tests.The data were analyzed by software DPS.As a result,a satisfactory ISSR reaction system for H.inermis with desirable repeatability and polymorphic bands was established.The optimized ISSR-PCR system of H.inermis included 2.5 mmol·L-1Mg2+,1.25 U·25μL-1 Taq DNA polymerase,0.3μmol·L-1 primer,350 ng·25μL-1 DNA template and 0.15 mmol·L-1 dNTPs in 25μL PCR reaction system.Ten primers with stable amplification and rich polymorphism for ISSR were screened using this reaction system and its optimal annealing temperature for ISSR-PCR reaction was proposed by gradient PCR.This optimized ISSR-PCR reaction system would provide the basis for the analysis of genetic diversity,phylogenetic analysis,physiological or pathological events and genetic variation of important traits of H.inermis.
The authors conducted a field investigation in Hengqin Island Sea in May 2008,and studied the chlorophyll a content, primary production,zooplankton and phytoplankton.Some parameters such as composition,community structure,abundance and biomass of phytoplankton and zooplankton were analyzed.The results showed that the average chlorophyll a content and primary production was 5.27 mg·m-3 and 123.56 mg·m-2·d-1,respectively.111 phytoplankton species were identified.Phytoplankton communities were dominated by Bacillariophyta and the absolute dominant species was Skeletonema costatum.The main ecological group of phytoplankton was nearshore group;the average cell density of phytoplankton was 6 832.75×104 cell·m-3.41 zooplankton species were identified,among which the absolute dominant species is Acartiella sinensis.The main ecological group of zooplankton was warm water nearshore group.The average abundance and biomass of zooplankton were 742.25 ind·m-3 and 131.12 mg·m-3 respectively;the average diversity index and evenness of zooplankton were 2.54 and 0.67,respectively.
Traditional atomic absorption spectroscopy method and the environmental scanning electron microscopy method are compared in analyzing the distribution of heavy metal Pb and Cd in rice grain.Two methods show that the concentrations of Pb and Cd in different parts of rice caryopsis are in the order of embryo>aleuron layer>pericarp>external endosperm>center of caryopses.Smaller difference in the content of Pb and Cd is found in embryo,aleurone layer and pericarp;besides,little difference exists in the whole endosperm,but the contents of Pb and Cd in embryo,aleurone layer and pericarp are significantly higher than in the endosperm.Environmental scanning electron microscopy can accurately reflect the difference of distribution of heavy metals in different parts of plant,and there is no obvious difference as compared to atomic absorption spectroscopy. Environmental scanning electron microscopy method is easy and quick;however,it can only detect qualitatively but can not detect accurately the content of elements in a specific part,so it can not take the place of the traditional method.
The contents of 16 kinds of organophosphorous pesticides(OPPs) were detected using the method of gas chromatography(GC) in vegetable,fruit and foodstuff so as to understand the residues and distribution of OPPs in farm products in Guangzhou.50 samples were detected and 96.0% of the samples were found to be with OPPs residues.The detected rates were 96.8% for vegetable,100% for fruit and 80.0% for foodstuff.The total exceeding rate for each component of OPPs in 50 samples was 36.0%,and the exceeding rate was 41.9%,21.4% and 40.0% for vegetable,fruit and foodstuff.The highest exceeding rate of 32.0% was found in malathion among 16 kinds of OPPs.The residue of sumithion was detected to be 1308.7μg·kg-1,the highest average residue in OPPs in farm products,followed by phoxim and methamidophos,the residues of which were 970.1μg·kg-1 and 737.6μg·kg-1.It suggests that correct guidance and supervision in the application of OPPs in agriculture are necessary.
Allelopathic effects are allelochemical dose dependent.Whole-range assessment is a method for analyzing allelopathic dose-response data,which relies on calculating an inhibition index over a range of allelochemical doses to evaluate allelopathic effects.Based on the non-linear characteristics of dose responses,this study,by employing Monte Carlo Simulation,provided a better scientific computing method for inhibition index.Examples fiom the literature were used to demonstrate the effectiveness of the method.
This article compares the treatment effect of a series of coagulation tests,by changing the test conditions,and using a new type polymer coagulant,aluminum sulfate and PAC on wood-based pulp and paper mills integrated wastewater treatment. The experimental results show that at the best pH value and dosage conditions new polymer coagulant integrated pulp and paper deals with the waste water relatively the best.When pH is 8.29 and dosage is 175 mg·L-1,even if CPAM is not added,the removal rate of COD,turbidity,chroma is 87.4%,96.4% and 89.5%.COD and chroma of the effluent are 90 mg·L-1 and 32 times respectively,which can meet the first grade of secondary period of Local Standard Discharge Limits of Water Pollutants of Guangdong Province(DB 44/26-2001).
A municipal wastewater treatment plant in Zhaoqing city capable of treating 20000 m3·d-1 wastewater was available in June 2008.With the success of cultivating activated sludge in July,the adjustment of treatment parameters was performed to improve the treatment efficiency in the following two months that ensured the effective operation of the plant in November.By using the standard monitoring methods,several kinds of contaminants and indexes,including chemical oxygen demand(CODCr), biochemical oxygen demand(BOD5),ammonia-nitrogen(NH4+-N) and total phosphorus(TP) were utilized to determine the treatment efficiency of the plant.The results showed that the influent consistency of CODCr,BOD5,NH4+-N and TP ranged from 117.3 to 446.4 mg·L-1,60.5 to 225.9 mg·L-1,7.6 to 34.3 mg·L-1,and 1.85 to 5.49 mg·L-1 respectively.After treated,the cyclic activated sludge system could dramatically decrease the concentration of those contaminants to 18.6 to 63.2 mg·L-1, 8.0 to 29.2 mg·L-1,2.0 to 8.8 mg·L-1,and 0.22 to 0.83 mg·L-1.Effluent could return back into the environment with the match of discharge standard of pollutants for municipal wastewater treatment plant and local criteria.The total amounts of bacteria,yeast and mould were 4.2×1010±1.8×1010 CFU,2.5×107±1.8×107 CFU,and 3.6×106±2.6×106 CFU per gram dry sludge respectively in the operation period.
Frequent occurrence of cyanophyta water-blooms destroyed the ecological environment,affected on human health and sustainable development of society and economy in some areas.Cyanobacterial early-warning system can provide real-time technology support for treatment and mitigation of this environmental disaster.This paper reviews the status of cyanobacterial early-warning and monitoring technologies firstly.Then,in order to decrease the negative effect and loss caused by cyanobacteria bloom effectively,suggestions to improve monitoring system are also proposed based on the data analysis in recent years to the west Chaohu Lake monitoring.
This paper discusses the controlling limit of the formulating emission standard of air pollutants for cement industry in Guangdong Province by analyzing the Emission Standard of Air Pollutants for Cement Industry(GB4915-2004) and the relevant standards abroad,and combining the results of researching and the presented technology of controlling dust,sulfur dioxide, nitrogen oxides,fluoride,etc.It is proposed that there is still some room,but not large,for the emission standards of local cement in Guangdong Province to be strict.Treating Pearl River Delta and other mountains areas differently,making a difference between the existing cement plants and the new-built ones by different time,guiding the cement industry to introduce new technologies and transfering to the base of clinker are still needed,and this will be a highlight in pollutant emission standards of cement industry in Guangdong Province to achieve the environmental planning requirements of the"Eleventh Five-Year".
To meet the needs of the society,ecology specialty was established in Jinan University in 2003,relying on the national key discipline of hydrobiology,and till now two batches of students have graduated from this specialty.The teaching practices in curriculum setup,talent training goal and construction of teaching staff from the beginning of running this specialty to now were summarized and reviewed in this article.
Botanical experiment is one of the basic courses for the students majoring in Ecology.The teaching reform of botany experiment in Ecology Department should optimize the curriculum system according to the characteristics of the major and the scientific advantages of teachers,and this can get progress from teaching practice,and promote the practical and creative abilities of students.This teaching reform was carried out in undergraduate students of Ecology Department,grade 2007.The reform included three aspects:optimization and combination of experimental contents,arousing students' interests in scientific research work,and strengthening the practice.The teaching reform has achieved good results in the practice.
