A field experiment was carried out to study CH4 emissions from rice field as affected by two levels of soil tillage intensity(digging tillage and rotary tillage) and three rice cultivation patterns(direct seeding,seedling throwing and hand transplanting).Results show that the same in rice cultivation pattern,the tillage intensity treatments,digging and rotary tillage presented the same trend of seasonal variation in CH4 flux.The effect of tillage intensity on total CH4 emission during the rice-growing period depended on rice cultivation pattern: compared with digging tillage,rotary tillage decreased CH4 emission significantly by 31.37% with seedling throwing adopted;and did not have much effect with direct seeding and hand transplanting adopted.Rice cultivation pattern had significant effects on seasonal variation of CH4 flux.The CH4 flux in direct seeding treatment showed roughly a "two-peak" seasonal variation curve,being relatively low at the early rice growing stage.The CH4 flux in transplanting treatments(seedling throwing and hand transplanting) displayed "three-peak" seasonal variation curve,being relatively high at the early rice growing stage and reaching the highest level on D12 after rice transplanting.With digging tillage,the total CH4 emissions,regardless of rice cultivation patterns,all increased,but did in the order of seedling throwing> direct seeding> hand transplanting.With digging tillage,compared with seedling throwing,direct seeding and hand transplanting decreased CH4 emission by 23.31% and 42.51%,respectively;with rotary tillage,total CH4 emission in the three rice cultivation patterns were almost the same.Reducing soil tillage intensity by using rotary tillage instead of digging tillage could reduce disturbance of soil,thereby decreasing CH4 emission from the rice field to some extent.Compared with rice transplanting,rice direct seeding could significantly decrease CH4 emission at the early rice growing stage,which obviously has some potential in CH4 reduction,but field water management needs to be intensified at the middle and late stages of the rice growing season.

A field experiment was conducted to investigate influence of cropping systems on CH4 and N2O emissions from paddy field during the winter upland crop growing season.The experiment was designed to have five treatments,i.e.fallow,oil-seed rape with nitrogen(OR-N) or without nitrogen(OR-ck),wheat with nitrogen(W-N) or without nitrogen(W-ck).Results show that paddy field was obviously an N2O source,and a weak source or sink for CH4 as well during the winter upland crop season.Results also demonstrate that N2O emissions were significantly enhanced by nitrogen fertilization and peaked after each rainfall event,showing significant influence by soil water content.The seasonal mean of N2O fluxes for W-N and OR-N treatments was 18.51 and 13.47 μg·m-2·h-1,respectively,while the cumulative seasonal emission was 87.31 and 59.48 mg·m-2,respectively,being obviously higher than those in the control and fallow treatment.Though there was no significant difference in seasonal mean,there was in cumulative emission between wheat and oil-seed rape.On a 100-year time horizon,the integrated global warming potential of the treatments was assessed to be in the following sequence: OR-N>W-N>W-ck>fallow>OR-ck,in which N2O was the major contributor from the N fertilized treatments while CH4 was the major contributor from the no N treatments and that is unnegligible.

An O3-FACE(free-air O3 concentration enrichment) system was set up in a wheat field to investigate effects of elevated surface O3 concentration,which was 70 nmol·mol-1 on average,on wheat N-uptake,soil total N and mineral N,urease activity,and populations of ammonia-oxidizing bacteria(AOB) and denitrifying bacteria(DNB) at various wheat growth stages,as well as soil nitrification and denitrification potentials at the wheat harvesting stage.Compared with the ambient O3concentration,which was 45 nmol·mol-1,elevated O3 concentration increased individual wheat N-uptake,while decreased soil total N,NH4+-N and NO-3-N contents.At the wheat harvesting stage,soil total N and NH4+-N contents decreased significantly(P<0.05) by 9% and 71%,respectively,and so did soil NO3--N content by 36%.During the growth periods of wheat,elevated O3 concentration tended to enhance soil urease activity,which was significantly(P<0.05) higher than that in the ambient soil at the jointing,heading and filling stages of wheat,and to increase the population of soil AOB and DNB,as well,which were significantly(P<0.05) higher than those in the ambient soil at the wheat harvesting stage.At that time,although in O3-fumigated soils the specific nitrification potential of AOB tended to decrease,and the soil total nitrification potential to increase,while the specific denitrification potential of DNB decreased significantly(P<0.05) by 96% and the soil total denitrification potential remained unchanged,which suggests that elevated surface O3 concentration promoted wheat N-uptake,inhibited soil N storage,and then accelerated soil N transformation,which was represented by enhanced urease activity,and bigger population sizes of soil AOB and DNB with low metabolic activity.

Ecological pressure and ecological elasticity are the two important forces affecting ecosystems.Based on the interactions of the two,an index system was established for evaluation of ecological carrying capacity and with the Yangtze River Delta being a case for study,ecological carrying capacity of the complex system was evaluated.Results show that though the ecological pressure index of the region,including Shanghai City,Jiangsu Province and Zhejiang Province,somewhat fluctuated,on the whole it rose gradually in the past ten years and its ecological elasticity demonstrated basically a rising trend and its ecological carrying capacity did an improving trend as well.Nevertheless,the region is still under high pressure,and even in a state of ecological imbalance.

The Taihang Mountains,Hebei Province was selected as study area for performance of early warning of ecological safety of land resources and quantitative measurement of impacts of various sensitive factors on outcome of the early warning using a fuzzy optimization model and a scenario analysis model.Results show that the warning of the land resources ecological safety in the study zone could be sorted into three levels,Yellow Alert,Blue Alert and Green Alert(of a five level alert system,green,blue,yellow,orange and red).The area was dominated by Blue Alert,which covered over 50% in acreage.On the time scale,the overall situation of the zone is improving slowly.And on the spatial scale,the middle section of the area has somewhat improved,but the north and south tips are getting serious,especially the latter.Ten sensitive factors(weighing factor>0.03) are the most important factors affecting the ecological safety in the study area.Their integrated contribution to safety of the whole ecological system should have aroused sufficient attention.In terms of contribution rate to the general system,the subsystems follow the order of status subsystem>pressure subsystem>response subsystem.So it is essential to regulate selectively the subsystems and the general system.

The importance of soil organic carbon(SOC) in forest soils to the global carbon cycle depends on stability of this soil carbon.However,little is yet known about changes in stability of SOC during the development of fir plantations.To scientifically evaluate the carbon pool function and carbon sequestration potential of the soils under Chinese fir plantations,investigations were done of biochemical characteristics and degree of physical protection of the soil organic carbon in the soils under Chinese fir plantations different in growth stage.Results show that the contents of total SOC,microbial biomass carbon(MBC),labile pool I(LP I),labile pool II(LP II),heavy organic carbon(HOC),and microbial quotient(MQ) fell to the bottom at the middle-age stage,while the contents of light organic carbon(LOC) and recalcitrant fraction(RF) increased with the age of the stands,but the proportion of recalcitrant fraction in SOC increased first and decreased afterwards,which means that it peaked at the middle-age stage,and ranged from 41.9% to 57.6% under the stand at the mature stage,and from 38.7% to 43.0% under the stand at the young stage.The proportion of HOC in SOC ranged from 86.4% to 87.5% under the stand at the young stage and from 82.5% to 83.9% under the stand at the mature stage.On the whole,the development of a Chinese fir plantation is a process of SOC accumulation in the soil,and during the process SOC per se increased in recalcitrance while decreased in the degree of physical protection.Besides,among all the fractions researched in this study,LP I is the highest in availability to soil microbial biomass.

Water samples were collected from the water area of the Dalian Lake,Shanghai in the four seasons of 2009,separately,for analysis of Pielou evenness index,Shanon-Wienner diversity index,Margalef richness index and Mcnaughton index to study community structure characteristics of the phytoplankton in the lake and of physicochemical indices to evaluate trophic state of the waterbody.Results show that a total of 64 species of phytoplankton were identified,belonging to 40 genera of 7 phyla in the water samples from the Dalian Lake.Chlorophyta was the dominant phylum,the highest in species,and followd by the phyla of Cyanophyta and Bacillariophyta.Density of the phytoplankton varied in the range from 0.35×106 to 10.87×106 L-1.Dominant species of the phytoplankton varied significantly with the seasons and their number ranged from 9 to 14.Their Mcnaughton indices,however,were not high,ranging from 0.02 to 0.60.Based on the characteristics of the phytoplankton community structure,such as density and dominant species,the water in the lake was evaluated to be between mesotrophication and eutrophication,but the evaluations based on Pielou eveness index,Shanon-Wienner diversity index and Margalef richness index differed sharply.The results of evaluation based on Pielou evenness index was basically consistent with the results of evaluation that based on phytoplankton density,species dominance and physicochemical indices,which indicates that the Pielou evenness index is suitable to evaluate eutrophication state of the waterbody of the Dalian Lake and the evaluation of Shannon-Wiener diversity index and Margalef richness index didn′t tally with the actual situation,which indicates the two indices are not applicable to evaluating eutrophication state of the waterbody of the Dalian Lake.

Characteristics i.e.species diversity and community structure,of the ciliate community in the Linxia Section of the Daxiahe River in low water seasons were studied by analyzing with microscopy and fixed cell staining method.16 water samples were collected in two times from that section during the period from November 2008 till March 2009.A total of 114 species(including 9 unidentified),belonging to 57 genera of 45 families of 13 orders,were identified.Colpidium colpoda and Tetrahymena pyriformis were dominant species,while Paramecium caudatum,Cyclidium citrullus,Litonotus fasciola,Glaucoma macrostoma,C.campylum,Vorticella microstoma and Cohnilembus fusiformis were sub-dominant ones.They can be cited as indicator species for domestic organic pollution of rivers.Integrated evaluation of the environmental quality of the Daxiahe River was conducted based on the characteristics of ciliate community(number of species,dominant species,biodiversity index,saprobic index,percentage of BS groups,percentage of PA groups,community similarity index) and other biodiversity index,such as fecal coliform bacteria.Results show that the water body is mainly polluted by organic pollutants of domestic sewage.The pollution can be divided into four levels,that is,slightly polluted(Os in Section 1#),moderately polluted(α-ms in Section 4#),moderately polluted(α-ms in Section 2#) and near-heavily polluted(α-ms-Ps in Section 3#).

The Taihu Lake is the third largest fresh water lake in China.Recently,it has seen heavy cyanobacterial blooms in the lake almost every year.Samples of cyanobacteria were collected from Nanquan area of the Taihu Lake in July,September and October 2008 for analysis of contents of 19 elements(Na,Mg,K,Ca,Zn,Mn,Fe,Al,Cu,Cr,Co,Ni,As,Se,Mo,Ag,Tl,Cd and Pb) therein and variation of the composition,using an Agilent 7500ce inductively coupled plasma mass spectroscopy(ICP-MS).All the 19 elements,except for Tl,which was undetectable,evidently accumulated to varying levels in the cyanobacteria.The concentrations of Ca,K,Na,Mg,Al and Fe were commonly>1 000 μg·g-1 dry weight(esp.Ca and K were>4 000 μg·g-1 dry weight).From July to October,Ca remained relatively stable in concentration,while K,Mg and Na gradually increased.The concentrations of Al and Fe were the highest in July,but dropped sharply in September.Mn,Zn,Ni,and Cu,found to be moderate in concentration(10-100 μg·g-1 dry weight),peaked in July and bottomed in September and October.In contrast,Co,Mo,and Se were measured to be low in concentration(<1 μg·g-1 dry weight).And some toxic elements As(5-15 μg·g-1 dry weight),Cr,Cd,Pb and Ag(<5 μg·g-1 dry weight) were detected in cyanobacteria,and usually peaked in concentration in July.Based on the aforementioned results and the provincial government reports on the physical removal of cyanobacteria in the Taihu Lake in 2007-2009,it is estimated that approximately 595.89 t of K,544.03 t of Ca,181.18 t of Mg,83.06 t of Al,63.97 t of Na,55.45 t of Fe,2.99 t of Mn,2.26 t of Zn,1.67 t of Ni,1.11 t of Cu,0.76 t of As,94.5 kg of Cr,82.70 kg of Cd,45.01 kg of Se,37.64 kg of Pb,32.27 kg of Co,5.41 kg of Mo and 2.46 kg of Ag were consequently removed from the Taihu Lake during the same period.The findings of this study may serve as fundamental insights for further investigation of the elemental effect on the occurrence and development of cyanobacterial water blooms,and furthermore,provide important evidence for making use of the bioaccumulation properties of cyanobacteria to reduce toxic element loads and conserve the fishery environment of the Taihu Lake.

Tetracycline is one of the widely used antibiotics for animals as prescription drugs and as growth promoters in livestock.As a matter of fact,much of the tetracycline is excreted with urine or feces and released into the aquatic environment through many pathways,thus posing a potential threat to aquatic organisms.Microcystis aeruginosa is an important algae in the aquatic ecosystem.In order to determine toxic effects of tetracycline on non-target aquatic organisms,M.aeruginosa was used as a subject in this study,and effects of tetracycline on photosynthesis and antioxidant enzymes of M.aeruginosa were investigated.Results show that exposed to tetracycline(0.80-35.00 mg·L-1),the algae declined significantly in chlorophyll fluorescence and potential maximal relatively electron transport rate(Re,t,max).The inhibiting effects intensified with the increase in concentration of tetracycline,with the maximal inhibitation rates being 39.95% and 44.08%,respectively,after 4 days,and rising up to 59.48% and 91.90% after 7 days.The activity of superoxide dismutase(SOD) in the algae dulled by 30.36%-35.92% and 25.03%-35.51% after 4 and 7 days of exposure,respectively,and no significant difference was found among treatments different in tetracycline concentration.The activity of peroxydase(POD) was intensified after 7 days of exposure.The findings indicate that tetracycline hinders photosynthesis of M.aeruginosa,disturbs balance of the antioxidant enzymes system,and then inhibits growth of the algae.

To search for a new type of algicide,low in toxicity but high in effect,inhibiting effects of β-cycloamylose-chathrated copper(β-CD) chlorophyllin and β-CD ammonium copper chlorophyllin on Synechocystis sp.PCC6803 were investigated.Results show that β-CD copper chlorophyllin and β-CD ammonium copper chlorophyllin were more effective in inhibiting Synechocystis than CuSO4,completely inhibiting growth of the alga when their Cu2+ concentration was 2.5 and 1.5 μmol·L-1,separately.They could decrease the intensity of chlorophyll fluorescence and the activity of nitrate reductase of the alga,but induce the activities of its phosphatase and anti-oxidation system and improve its membrane permeability(P<0.05).It is presumed that the toxic mechanism of the β-CD copper chlorophyllin and β-CD ammonium copper chlorophyllin inhibiting Synechocystis was similar to that of inorganic copper ion.

A comparison study was carried out on effects of mixing-immobilization(MI) and stratifying-immobilization(SI) of algae and bacteria removing nitrogen and phosphorus from aquacultural wastewater and influence of light intensity and temperature on the effects.Stratifying-immobilization was done in two forms,SI1and SI2.The former had algae in the outer layer and bacteria in the inner one,whereas the latter did reversely.Results show that under given conditions for 72 h,MI and SI2 removed 91.20% and 90.77%,respectively,of the nitrogen in the wastewater,while SI1 did only 60.4%.However,MI and SI1 were much better in removing phosphorus than SI2,MI and SI1 was 90.31% and 84.78%,respectively,in phosphorus removal rate,whereas SI2 was only 32.09%.When light intensity was set at <6 000 lx,the nitrogen removal rate of SI2 was over 88%,much higher than that of MI and SI1(80%);and when light intensity was high enough(>6 000 lx),the nitrogen removal rates of both SI2 or MI were over 89%,higher than that of SI1.The optimal temperature for nitrogen and phosphorus removal was 20～30 ℃ in all the three treatments,MI,SI1 and SI2.

A constructed complex wetland model,consisting of a first-step vertical flow wetland(VFW),four sequential submerged macrophyte oxidation ponds and a second-step VFW,was used to treat tailwater from a small urban wastewater treatment plant.Results show that when the hydraulic loading of the model was 0.13 m3·m-2·d-1,the outflow had only CODCr and NH4+-N up to Grade Ⅲ Criteria of the Environmental Quality Standards for Surface Water(GB 3838-2002),but when ρ(TP) in the inflow satisfied Grade Ⅰ B Criteria of the standard for pollutant discharge from municipal wastewater treatment plants(GB 18918-2000),TP in the outflow also met Grade Ⅲ Criteria of the Environmental Quality Standards for Surface Water.When the hydraulic loading at the second-step VFW was adjusted to 0.06 m3·m-2·d-1,both effluent TP and TN finally met the Grade Ⅲ Criteria.It is assumed that in the model,TN was removed mainly by filtration and adsorption in first-step VFW and by denitrification in the second-step VFW,while TP was mainly removed through adsorption and sedimentation by limestone in first-step VFW.

Three different types of drainage ditches,ecological ditch,control ditch #1 and control ditch #2 were built up in the field for study of their respective effectiveness in intercepting particulates in drainage and their mechanisms.It was found that the effectiveness of the ecological ditch removing N and P from drainage was manifested in N and P uptake by ditch plants,adsorption by substrates and uptake by plants in the filter box,reduced flow rate and silt settlement caused by intercepting dams in ditch,etc.Of the total N and P in the drainage of the summer experiment,68.30% and 78.45% were removed by ditch plants,1.05%and 5.05% by sediment.Of the total N and P in the drainage of the winter experiment,0.37%and 1.55% were removed by filter-box plants,10.82%and 37.94% by filter-box substrate.Moreover,the ecological ditch with interception dams was twice as much effective as the controls in extending the hydraulic retention time(HRT).

The ability of bamboo charcoal particles as absorbent has been well proved.Bamboo charcoals treated with different acid and alkaline solutions were used to study effectiveness of their particles adsorbing malachite green in aqueous solutions and further adsorption kinetics of the bamboo charcoal particles screened out in the preceding study.And then the resultant data were fitted with the pseudo-second order kinetic model and particle diffusion model.On such a basis,factors affecting the adsorption process were explored.Results show that the bamboo charcoal particles modified with 0.5 mol·L-1 NaOH solution were the most effective in adsorbing malachite green,adsorbing as much as 9.96 mg·g-1.The particle diffusion model can better describe the kinetic process of adsorption.The mass and size of bamboo charcoal particles,the initial concentration of malachite green in the solution,agitation speed and the initial pH value of the aqueous solution are all potential factors affecting the adsorption process.

Effects of regulation of pH and application of organic material on adsorption and desorption of phosphorus in red soil,latosol and paddy soil were studied.It was found that both adsorption and desorption of phosphorus in latosol and paddy soil decreased with rising pH,but the phenomenon was not as significant in red soil.Soil cation exchange capacity,contents of organic matter,iron and aluminum oxides were the main factors affecting adsorption and desorption of phosphorus in these soils.Red soil was low in CEC and content of organic matter,and high in content of Fe/Al oxides,leading to higher adsorption of phosphorus in red soil than in other two soils,while latosol and paddy soil were high in CEC and content of organic matter,which formed a high repulsive force on soil surface and an organic matter coating covering P adsorption sites on the surface,respectively,thus making the two soils adsorb less P than red soil did.Incorporation of rice straw and incubation under a given temperature decreased P adsorption significantly in red soil and paddy soil,but the effect was not as significant in latosol.However,incorporation of rice straw increased P desorption and its desorption rate in these soils,thus improving mobility of adsorbed phosphorus therein.

To apply support vector machine(SVM) for evaluation of eco-environment,it is essential to give priority to designing the classifier and picking kernel functions,their parameters and penalty factors.Described here are the ways of choosing decision-tree as SVM multi-class classification method and radical base kernel functions to build a decision-tree-based SVM evaluation model for eco-environment level.Self-adaptive optimization of penalty factors and kernel function parameters is realized.The evaluation model is tested for eco-environment evaluation of some major cities and provinces of China.The test demonstrates that SVM is a good method to evaluate eco-environmental quality.

Pollution of the soil in a typical solid waste dismantling area in the coastal region of east Zhejiang was investigated and analyzed,and degrees of soil heavy metal pollution were assessed.Results show that against the background values of the soil environment,the studied soil was seriously polluted,and over 50% of the soil was above moderately polluted with Cd and Cu.On such a basis,exploration of how to demarcate heavy metal contaminated soil was conducted and a whole set of polluted soil expression methods for land-quality-specific management of the soils was put forward.

Methodology and procedures for studying soil remediation goals are introduced,based on human health risk assessment.Properties of PAH-contaminated soil and exposure scenario in the landfill site are analyzed and simulated.Results show that the maximum exposure intake(MEIs) benzo(a)pyrene by oral ingestion and dermal contact is 1.89×10-6 and 0.93×10-6 mg·kg-1·d-1,respectively.The maximum carcinogenic risk(MCRs) of the two exposure pathways is at 1.38×10-5 and 6.79×10-6,separately,both of which exceed the acceptable carcinogenic risk level of 10-6.This level is the benchmark regulated for assessing the human health impact from the individual carcinogenic contaminant in China.The MEI of benzo(a)pyrene by inhalation is 7.79×10-10 mg·m-3 and its MCR is 6.86×10-10.Taking into account site-specific geo-condition and parameters,the remediation targets(w,mg·kg-1)of 5 PAHs,including benzo(a)pyrene,dibenzo(a,h)anthracene,benzo(a)anthracene,benzo(b)fluoranthene and benzo(k)fluoranthene,for reuse of the mid-layer of overlying soil in landfill sites are set at 0.994,0.995,9.95,9.95 and 99.5,respectively.

A total of 9 farmer households(3 high,3 medium and 3 low in income level),typical of the Taihu Lake basin,were selected for studying quantitatively production and discharge coefficients of various pollutants in sewage from the rural areas of the basin through in-situ monitoring and indoor survey.It was found that income level had no significant influence on production coefficient of TN,NH4+-N and TP in total wastewater,but had on wastewater quantity,COD production coefficient and discharge coefficients of various kinds of pollutants in total wastewater,showing an order of high income household> medium income household > low income household in effect.The contribution of toilet wastewater to the total pollutant load was very high,reaching 67% or over in COD,and 84% or over in TN,NH+4-N and TP,so the utilization and treatment rates of toilet wastewater are the leading factors influencing discharge coefficient of pollutants,while agricultural income level and septic tank type have significant influence on the two factors.

Biodiversity protection in agricultural landscaping should get more attention than ever before as an important component of the global biological diversity protection and as the basis for food security and ecosystem stability as well,although agricultural activities contribute greatly to the loss of the global biodiversity.General principles for biodiversity protection in agro-landscaping,which was considered complementarity between patterns and processes in landscape ecology,were brought forth,including identifying and prioritizing the hotspots in agro-landscaping,protecting or establishing natural or semi-natural habitats,diversifying the land use/cropping system,increasing the connectivity by connecting the remaining natural and semi-natural habitats or establishing ecological corridor,expanding the area of farmlands low in farming intensity,adopting wild-life friendly farming management practices,preserving key species and maintaining interrelations among species,controlling aggressive over-abundant invasive species.Finally,problems in practical application of the above mentioned principles are discussed.