To improve landscape management with a view to promote diversity of natural enemies for controlling pest population to a lower level has become a new approach to bio-control of pest in recent years. A review is presented of the researches done both at home and abroad in this aspect, with emphasis on introducing principles of regulating agricultural landscape biodiversity and pest bio-control. And the landscape-management-based approaches to bio-control of pest in agricultural landscape is also summarizes. In the end, the  problems with and orientation of the approaches in the current scenario of agricultural policies in China are discussed.

Environmental quality of a place is an important factor that directly affects quality of the agricultural produce therefrom. Different standards for environmental quality are adopted for different crops and different quality management systems in China. A comparative study was performed to systematically analyze the criteria set in the national standards and trade standards for environmental quality for the production of general agricultural produce, green food, pollution-free agricultural product, and organic product, from three aspects i. e. distribution of standards, environment factors detection index systems and limit values of detection indices, and specify similarities of and differences between the environmental quality test index systems for producing areas of the three types of agricultural produce. Results show that for pollution-free agricultural product producing areas, the criteria for environmental quality are the most in number, covering a complete in ventory of agricultural produce and all criterion levels; for green food producing areas, there are not so many criteria; and for organic product producing areas, no specific criteria have been set yet, and the criteria for producing general agricultural products are used. In terms of strictness, the criteria for green food are the highest and followed by those for pollution-free agricultural product and then those for organic product (as general agricultural produce). Further comparison of the three important environmental factors in requirement of the three systems shows that soil quality is the most important factor, for which the requirements varied sharply between the three systems, irrigation water quality comes next and air quality the last in variation of requirement. In the end some problems existing currently in standard formulation are discussed, i. e. lack of uniform names and units for environmental indices, incompatibility of the standards, and absence of specific environmental criteria for organic product producing areas. The study was conducted in the hope that the findings will serve as reference for the ongoing zoning of organic product producing areas in the light of environmental superiority and revision of the environmental standards for producing areas of the three types of agricultural produce.

How to calculate discharge of pollutants from the livestock and poultry breeding industry is critical to judgment of environment situation as well as planning and decision-making for the environment, and the calculation is an important basic datum for designing livestock and poultry breeding pollution control projects. Pollutants producing and discharging coefficients are important basic data in the study of environment, and can be used as a fairly objective approach to calculation of pollutants discharge from the industry. The recent researches on pollutants producing and discharging coefficients of the livestock and poultry breeding industry in China are reviewed.The development courses, measuring methods and measurements of the coefficients in different regions of the country are collated systematically for comparison.Typical applications and improvements in the researches are summarized, and in the end the progresses in future researches in this field is forecasted.

China has the largest annual output of crop residues in the world, of which corn stalk makes the biggest proportion and distributes the most extensively in the country. Anaerobic digestion for biogas production is an effective method to utilize corn stalk. However, the compact structure of lignocellulose of the corn stalk per se may cause a series of problems in biogas production, such as low biogas yield, low methane content, low biodegradability and long fermentation process. Therefore, it is necessary to have corn stalk pretreated to break its original  structure and improve its biodegradability. A comprehensive review was conducted of recent progresses in the researches on technologies for pretreating corn stalk for biogas production, including physical, biological, and chemical approaches, for comparison. It is expected that the review may provide some references for selection of a proper corn stalk pretreatment method to improve biogas yield. 

Despite the significant achievements China has made in conserving and remedying the ecosystems, she still has to face the fact that the deteriorating trend of the overall ecological environment has not yet been fundamentally halted. Being defective in mechanism designing at the top level, fragmented in management, incomprehensive in means, weak in technical support and imperfect in support system, the existing management system fails to meet the challenge of solving the highly complicated problems in ecosystem conservation and remediation. The Third Plenary Session of the 18th Central Committee of the CPC called for establishment of a regional joint action mechanism for conservation and restoration of integrated land-sea ecosystems, which demands that with a view to integrity of the ecosystems, an appropriate eco-environment conservation and management system be established disregarding the boundaries between regions, between basins, between land and sea, between industries and  between ecological elements, and integrating all the elements, functions and means, so as to implement an integrated management of the ecosystem encompassing all the elements from mountain top to sea, all the processes and all the dimensions and preserve structural and functional integrity and health of the ecosystems. Modes of and experiences in conservation and remediation of ecosystems in other countries are elaborated,status quo of and problems in conservation and remediation of ecosystems in China are analyzed, and in the end some advice and suggestions for establishment of the regional joint action mechanism for conservation and remediation of the integrated land-sea ecosystems are put forth.

Invasive alien species are a major threats to biodiversity at the global level. China is among the countries most affected by invasive alien species. Especially in recent years, the situation has changed greatly, displaying a number of new characteristics. In coping with the changing situation, it is found that the governance system is incomplete, management strategy imperfect, technological support inadequate and management capacity insufficient in the country. It is, therefore,governance system, a “seamless” supervision network over the entire process of “introduction- population establishment – dissimilation and proliferation  – hazard formation”, and a set of control measures high in technical level and comprehensive applicability. To address the issue, a holistic governance system is brought forth, that including framework, targets, scope, objects, fundamental principles, main institutions and measures, which tentatively form a program for building up a supervision and management system for prevention and control of invasive alien species posing environmental hazards.

Based on 2 376 county-level forest birds distribution data available in China, analysis was done of distribution patterns of abundance of forest birds in breeding and wintering seasons and relationships between spatial distribution of the birds and environmental factors in the two seasons, using a multivariate statistical model . Results show that the regions of the southeastern section of the Himalaya, Hengduanshan, Qinling, Minshan, Qionglaishan, Xishuangbanna, the mountainous area in Southwest Guangxi, West Guangxi-South Guizhou, Wushan and Nanling in North Guangdong are all quite high in bird abundance. In the regions of the Xiao Hinggan Mountains, Changbai Mountains and Taihang Mountains, bird abundance is obviously higher in the breeding season than in the wintering season, while in the regions like Guangdong and South Yunnan, it goes reversely. Precipitation, temperature range and net primary productivity are the major factors influencing distribution of bird abundance in the two seasons. In addition, the seasonal environmental factors reflecting features of the seasonal environment explain the distribution patterns in the two seasons better than the annual environmental factors reflecting features of the annual environment. The productivity hypothesis, water-balance hypothesis and environmental stability hypothesis may better explain the distribution patterns of the forest bird abundance in the two seasons.

With sustainable utilization of cultivated land as the entry point, a modified farmland ecological footprint model based on energy analysis was used to rectify yield factors of the farmlands in Zhejiang Province from the angle of “National hectare” and “Provincial hectare”. On such a basis, temporal dynamic analysis was performed of sustainable utilization of the farmlands in Zhejiang during the years of 2003 ~ 2012, and spatial differentiation analysis was conducted of sustainable utilization of the farmlands in the 11 prefecture-level cities of Zhejiang in 2012. Results show that the ecological carrying capacity of farmland per-capita in Zhejiang during the years of 2003~2012 remained quite low and did not vary much; per capita ecological footprint of farmland declined while fluctuating; and the ecological deficit per capita was somewhat mitigated during the ten years, but the farmland ecological sustainability index remained in the range between 0.2150 and 0.2664, being at a moderate level of unsustainability. Besides, in 2012, though the 11 cities in Zhejiang Province all incurred large ecological deficits, they varied spatially in per capita ecological carrying capacity and ecological footprint of farmlands: Ningbo, Zhoushan, Shaoxing, Lishui, Taizhou and Jinhua were rated as moderate in unsustainability while Hangzhou, Wenzhou, Huzhou, Quzhou and Jiaxing were as high in unsustainability. These findings may provide some theoretical references and solutions for overall prediction and planning of farmland ecological security and farmland sustainable utilization in Zhejiang Province.

As land use is an important factor controlling outputs and stoichiometric proportions of soil nutrients in runoff from a catchment and hence affecting service functions of the various ecosystems within the catchment, determination of nutrient contents and their bio-stoichiometric proportions in runoff have become an important tool for evaluating ecological processes and waterbody nutrient status of the catchment. In order to follow variations of nitrogen and phosphorus concentrations and their stoichiometric proportions in runoffs with type of landscape in the Chaihe Catchment of the Dianchi Lake, water qualities were monitored spatio-temporally in the landscapes dominant of the catchment. Results show that (1) the surface runoff waters in the catchment were all far beyond the criteria of the national standard for water environment quality in China in N and P concentrations, and the pollutants existed mainly in the form of dissolved nitrogen and particulate phosphate; (2) nitrogen content in runoff in flatlands and phosphate content in runoff in the phosphorus mining areas varied quite sharply temporally, while nitrogen content in runoff did spatially in the early period of the wet season and phosphorus content did in the mid-wet season; and (3) according to previous studies, in which N:P ＜ 7 and ＞ 30 were set for grading of waterbodies in quality for limiting nutrients in runoff, the surface runoffs from flatlands and tablelands as a whole, were under the condition of phosphorus limitation and the surface runoff from the phosphate mining areas and forestlands in phosphorus-rich areas were under the condition of nitrogen limitation, while the runoffs in the greenhouse regions and the lower reaches of the Chaihe River was under the condition of none-limitation. It is, therefore, concluded that the effluent of the Chaihe River flowing into the Dianchi Lake tends to intensify the eutrophication risk of the Dianchi Lake.

Based on the data collected through surveys, monitoring and experiments, a study was carried out on nitrogen budgeting of the Huashan Hydrological Experiment Watershed in Chuzhou. A survey on population, crop planting area, fertilization, crop yield, livestock and poultry breeding was conducted and wet deposition of atmospheric nitrogen and nitrogen content in runoff and in grain and in straw were measured and analyzed. Nitrogen budgeting of the watershed in the two irrigation years from October, 2012 to September, 2013 and from October, 2013 to September, 2014 were worked out, and impacts of rainfall and runoff on N budgeting of the watershed were analyzed. Although wet deposition of atmospheric nitrogen was affected by precipitation, in the two irrigation years, the flux of atmospheric nitrogen deposition was 26.10 kg•(hm²•a)^-1 N and 26.32kg•(hm²•a)^-1 N, separately, posing a difference of less than 1%, and the modulus of nitrogen loss with runoff was 3.86 kg•(hm²•a)^-1 N and 8.95kg•(hm²•a^)-1 N, separately, accounting for 6.54% and 13.98% of the total nitrogen output of their respective years, with the latter being over twice as high as the former; chemical fertilizer nitrogen was the main nitrogen input of the watershed, contributing 50.46% and 50.36% to the total nitrogen inputs；nitrogen removal with crop harvest was the main nitrogen output of the watershed, accounting for 56.68% and 52.17% of the total nitrogen output；nitrogen surplus was 59.94 kg•(hm²•a)^-1 N and 55.06kg•(hm²•a)^-1 N separately for the two years. Therefore, it could be concluded that nitrogen loss is related to runoff and that a potential trend towards eutrophication exists in the Huashan Hydrological Experimental Watershed.

Photosynthesis is the basis of energy flow in natural ecosystems and plants’ photosynthesis characteristics determine primary productivity of an ecosystem. Plant photosynthetic characteristics, though varying with different plant developmental stages, are not only an important factor influencing energy input of the eco-system, but also a major driving factor of regeneration and development of plant communities. In a forest ecosystem, photosynthetic physiologico-ecological characteristics of its dominant species affects the structure and function of the whole eco-system. The Funiu Mountain National Nature Reserve, sitting in the transitional zone between the north subtropics and the south warm-temperate, has preserved an intact type of forest ecosystem. Quercusvariabilis, as its main dominant species in areas of low altitude, regenerates nicely forming distinct layers. Photosynthesis of the plants of different development stages (arbor, shrub and seedling) was measured with a Li-6400 photosynthetic meter and a fluorimeter in the field, and chlorophyll contents in the plants determined in the laboratory. Results show that（1）the plant at its seedling stage is the highest in apparent quantum yield and in chlorophyll content, but the lowest in dark respiration rate and in light compensation point; （2）the plant at its arbor stage is the highest in high-light adaptability, but the lowest in chlorophyll content, and does not show any phenomenon of midday depression, and diurnal variation of its net photosynthesis at different layers is mainly governed by light intensity;（3）the plant at its arbor stage is the highest in PSⅡmaximum photochemical quantum yield, while the plant at its seeding, the lowest; and（4）the plant, regardless of growth stage, is higher in the morning than in the afternoon in stomatal conductance and in transpiration rate; and in water use efficiency, too, at all the stages, except the arbor stage, when it goes reversely. Such divergences of the plant in photosynthetic characteristics with the developmental stage enable it to adapt to different environments. That’s why the plants grow nicely at all stages, showing strong regeneration ability and an inherent impetus towards positive succession.

A field survey was carried out by sampling using pitfall trapping method to investigate diversity of topsoil layer dwelling arthropods in organic and conventional fields in Suning of Hebei and Gaotang and Caoxian of Shandong in the North China Plain. Comparison analysis was made of diversities at three taxonomic levels, such as the suborder of Arthropod, the sub-family of Coleopetera and the sub-species of Carabidae, structural composition and distribution of different arthropod communities, relative to farming pattern, organic or conventional, so as to evaluate effect of organic farming on biodiversity in farmlands and determine whether difference exists between evaluations using bio-indicators different in taxonomic level.  Results show that (1) in Caoxian County, organic fields were higher than conventional fields in abundance of Arthropods at all the three taxonomic levels; in Gaotang County, it was so only in abundance of the suborder of Arthropods and in Suning County, no big difference was found in abundance of Arthropods at all the three taxonomic levels between the two farming patterns. (2) in terms of richness of Arthropods, significant differences were found between the two farming patterns at the taxonomic levels of the sub-family of Coleoptera Families and the sub-species of Carabidae in Caoxian County only; besides, in terms of community structure, significant difference was found only in Caoxian County, partial difference in Gaotang County and nothing significant in Suning County. On the whole, organic fields are much higher than conventional fields in biodiversity of the three groups of arthropods and differences exist between the two farming patterns in structure of arthropod communities in the topsoil layer. However, the differences between the two vary with region and taxonomic level, which may be attributed to the number of years the fields have been under organic management. Evaluations of biodiversity in organic and conventional fields using bio-indicators based on different taxonomic levels may differ slightly, but basically consistent in general trend, indicating that it is more advisable to use bio-indicators based on high taxonomic level, e.g. the suborder of Arthropods or the sub-family of Coleoptera, to indicate effect of organic farming on environment, so as to reduce difficulty in classification and raise working efficiency. But bio-indicators based on the taxonomic level of sub-species of Carabid are more sensitive to difference in bio-diversity.

In order to study effect of type of woodland (Quercus variabilis, Populus spp. and Paulownia fortune) on species diversity of soil mesofauna in Gongyi, samples of soil mesoanimals were collected from the woodlands for analysis of variation of the soil mesofauna with the season and type of woodland in diversity. Results show that the woodlands different in type did not differ much in soil fauna diversity, analysis using the non-metric multi-dimensional scaling (NMDS) method reveals that Quercus variabilis varied sharply from Paulownia fortunei and Populus spp. In soil fauna community structure in spring and summer, while Paulownia fortune did not vary much from Populus spp.; and soil fauna diversity differed significantly between spring and summer (P<0.001),but not much between woodlands different in type (P>0.05). It was also found that elevation and height of herbosa did not have much effect on soil fauna diversity, but coverage of herbosa was negatively related to soil fauna diversity (P<0.05). The existence of soil fauna accelerates decomposition of woodland litters, and then promotes energy flow and material circulation in the woodland. At the same time, different types of woodland provide different types of habitats suitable for different types of soil fauna communities to inhabit and prey in. It is, therefore, very important to strengthen the protection of different types of woodlands for the development of soil fauna therein and bio-material flow in farming landscapes.

Soil microorganisms are an important component of a soil ecosystem. Long term continuous mono-cropping of potato was found to have altered the soil eco-system, thus affecting yield and quality of the crop. To confirm the finding, rhizospheric soil samples were collected from potato field sunder continuous mono-cropping different in cultivation history and fields under crop rotation (potato and sesame) for analysis of allelo chemicals and community structure and functions of soil microbes using gas chromatography-mass spectrometry(GC-MS), and the phospholipid fatty acids (PLFAs) biomarker method, separately. Results show that from the soil samples collected from fields under mono-cropping, the educts extracted with ethyl acetate, despite in what phase, acid, neutral and basic, all contained over 50% of iso-butyl phthalate ester and some cis-14-twenty nonaene, indicating apparent accumulation of esters, olefins and benzene substances in the soil, as compared with the soil under crop rotation. With mono-cropping going on, the soil microbial community displayed a trend, rising in the first 2-4 years, peaking after the 4th year , declining after 7-10 years and lingering in general at a low level after 10 years, in carbon utilization capacity. The groups of microbes living on carbohydrates as carbon source decreased significantly in metabolism and the groups living on carbohydrates, carboxylic acids and amino acid as metabolic substances were apparently inhibited. Among the main phospholipids fatty acids (PLFAs), those characterized by C16:1, C16:0, C18:2ω6t, C18:1ω9 caccounted for a high proportion. Contents of various fractions of PLFA varied with mono-cropping going on, all displaying a single peak curve. In the field under 4 years of mono-cropping, the soil biomass was the highest, and the biomass ratio of bacteria/microbial community increased, while the ratio of fungi/soil microbial community declined with mono-cropping going on. In the fields under crop rotation, community structure and biomass of the soil microbes were obviously improved. Iso-butyl phthalate ester and cis-14-twenty nonaene accumulated in the fields under long-term mono-cropping of potato may be the major allelo chemicals that hinder continuous mono-cropping of potato. These chemicals significantly alter community structure and functions of the soil microbes. The 5th year may be the critical point for continuous mono-cropping of potato.

Water level in wetland may affect soil properties of the wetland.Effects of water level on soil properties of reed wetlands in Hangzhou Bay Polder were studied. The vertical distribution patterns of the soil organic carbon (SOC), total nitrogen (TN) and total phosphorus (TP) along the soil profile and their stoichiometric ratios relative to water level were investigated. Results show that: (1) on the whole, SOC and TN contents decreased at first then increased with rising water level, while the content of TP did not change much(P<0.05); (2) when the soil remained unsubmerged (Water level 0) C/P, N/P and C/N declined with soil depth, but when the soil was submerged, regardless of water levels, their initial decreases were followed by increases; (3) SOC was positively correlated with soil N/P and TN with soil C/P, while TP was negatively, but not so significantly with soil C/N at all water levels; and (4) soil pH was the major factor affecting SOC, TN and TP at 0cm water level, but the effect faded with rising water level. SOC and TN accumulations in the deep soil layers increased with rising water level, while TP did not change much(P<0.05).

Effects of cultivation history of citrus orchard on structure of soil aggregates and soil organic carbon therein were studied using the spatio-temporal substitution method to explore stability of the soil organiccarbon in and carbon sequestration capacity of the orchard soil. Results show that a 30-year old orchard was 7.6%, 10.5% and 6.7%, higher than a 56-year old orchard, respectively, in content, mean weight diameter (MWD) and geometric mean diameter (GWD) of >0.25 mm water-stable aggregates (R_0.25), but.1.6% lower in fractal dimension, which suggests that soil aggregates decreased in stability with the cultivation going on. The effect of cultivation on characteristics of the soil organic carbon pool in the orchards was also quite remarkable. The 56-year old citrus orchard was 19.4% and 20%-80% higher than the 30-year old citrus orchard, respectively, in soil organic carbon storage in the 0-40 cm soil layer and in soil organic carbon storage in micro-aggregates (<0.25 mm). As organic carbon combined in micro-aggregates is protected physically, the 56-year old orchard was obviously higher than the 30-year old one in soil carbon sequestration capacity.

An in-situ simulation experiment was embedding rejuvenated algae-promoting strains of bacteria, Exiguobacterium sp.013 and Bacillus sp.D06, separately, with hypopuses of Microcystis aeruginosa, M.s flos-aqua and M. wesenbergii in wet sediment to compare effects of the formers on anabiosis of the latters Results show that as affected by E.sp013 the hypopuses of Microcystis aeruginosa, Microcystis flos-aqua and Microcystis wesenbergii started to resuscitate at a temperature 1℃ lower than that in their control groups, respectively. (11℃, 12℃ and 12℃, respectively), while B.spD06 did not have such an effect, but it did increase   resuscitation rates of the hypopuses. Under the same condition, E.sp013 was stronger than B.spD06 in effect of promoting resuscitation of the hypopuses. But both of them advanced resuscitation of the hypopuses in time by one day. No significant difference was found between the two strains of bacteria and between the three kinds of Microcystis in this effect (Duncans multiple range test, P> 0.05). The experiment also reveals that E.sp013 and B.spD06 bacteria reduced N\P ratio in the waterbody through their ability to assimilate N nutrient, thus removing N from the waterbody, which may be the reasons why the 2 strains of bacteria can promote resuscitation of the hypopuses of the 3 kinds of Microcystis.

In the light of the situation that odorant in the water source area of Shangshan Village was quite abnormal in Spring getting far beyond the standard for water source (2-Methylisoborneol content in the waterbody was about 16 times higher than the criterion set in the standard), a survey was launched of waterbodies and sediments within the range of 10km2 around the water sources protection zone. Results show that the conventional physical and chemical properties of the waterbodies in the region met the criteria of Grade I and II in the Standard for Surface Water Environment (GB3838-2002); and in the waterbodies and sediments the nutrient salts and algae did not contribute much directly to the odor from the water; Chlorophyll varied between 2.0 ~9.0 g·L^-1 and suspended solids between 20 ~ 40 mg·L^-1 in content, and were in low levels in most of the area. The content of nutrient salts was close to the criteria of Grade II of GB 3838-2002; In the sediments the content of total nitrogen and total phosphorus might reach as high as 3760mg/kg and 468mg/kg^-1, respectively, and the content of Cu and Zn as high as 50.1mg/kg and 115mg/kg^-1, respectively, and the area as a whole was a bit higher in content of the heavy metals. AVS content was also quite high in sludge, and might reach as high as 5.07μmol/g. The odorant in the water and sediment were more than 20 times higher than the standard, and tended to remain so. It was found that blooming of algae caused by eutrophication of the waterbody was not the reason why abnormal odor occurred in the Taihu Lake region in spring; rather the low temperature and rainfalls in spring caused occurrence of density currents in the bottom of the lake, which in turn triggered release of the odorant accumulated in the sludge into the waterbody. This is probably one of the explanations of why abnormal odor occurs in the Taihu Lake in spring.

Scenedesmus obliquus, a typical representative of the Phytoplankton group in freshwater ecosystems, is often used in aquatic toxicology tests and evaluation. Changes in cell density (D₆₅₀) and fluorescenceⅡparameters of Scendesmus obliquus under stresses of heavy metals ( Cu²⁺ , Zn²⁺ and Mn²⁺ ) different in concentration and different in duration ( 12 h, 24 h, 48 h, 72 h and 96 h )  were studied. The main parameters include maximal phototransformation efficiency of PSII (F_v / F_m), actual phototransformation efficiency of PSII in the light (Y), maximal relative electron transport rate (R_e,t,max), half-saturation light intensity (I_k) and light use efficiency (α) were determined. Results show that the heavy metals did not have much effect on growth of Scendesmus obliquus within 12 h and 24 h of exposure; however, Cu²⁺ and Zn²⁺ did have some significant effect inhibiting the growth of S. obliquus after 48 h of exposure. However, after 96 h of exposure, all the heavy metal treatments, except for the treatment of 100 µmol•L^-1 Mn²⁺, displayed significant effects inhibiting growth of the algae, and the treatments of Cu²⁺.did especially so. With the exposure going on, all fluorescence parameters (Fv / Fm,Y, R_e,t,max, I_k, α) decreased in value, but increased steadily in magnitude of the fall. All in all, in terms of toxicity to S. obliquus, the heavy metals displayed an order of Cu²⁺ > Zn²⁺ > Mn²⁺.  The findings of the study indicate that Fv/Fm, Yield and Ik can be used as indicators to evaluate adaptability of S. obliquus to Mn²⁺ and Zn²⁺, and fluorescenceⅡ parameters can be used to evaluate adaptability of the algae to Cu^2+.

Recent studies have reported that mercury accumulation in rice grains produced in Hg mining area may pose a potential health risk to consumers of the rice. Therefore, it could be of great importance to investigate how some key biogeochemical factors affect speciation and phytoavailability of mercury (especially methylmercury, MeHg) in contaminated paddy soils. To that end, aA pot experiment was carried out in greenhouse to investigate effects of addition of humic acid on production, phytoavailability, and bioaccumulation of methylmercury in an Hg-contaminated paddy soil. Results of the experiment show that addition of humic acid significantly reduced mercury methylation in the soil (Methylation-inhibiting  effect) by 41.7% in terms of time-weighted average concentration, as compared with CK, while it increased even more or by 277.0% of methylmercury in the soil porewater in terms of time-weighted average concentration, which may be attributed to the elevated concentration of dissolved organic matter in the porewater (Methylmercury mobilizing effect). Consequently, the amount of methylmercury accumulated in shoot of the rice plants  increased by 25.6%. Furthermore, the addition of humic acid caused significant increase in methylmercury translocation coefficient from soil to rice grains (Methylmercury translocating effect), thus leading to an evident increase (26.4%) in methylmercury accumulation in rice grains. However, the addition of humic acid also increased biomass of rice grains by 25.4%, thus diluting methylmercury concentration in grains (Methylmercury biodiluting effect). Consequently, the treatment of addition of humic acid and the treatment of CK were more or less the same in methylmercury concentration in grain.

To study effects of interplantation ratio on cadmium accumulation of two ecotypes (farmland  and mining) of  Bi?dens pilosa, a pot  experiment, designed to have six  treatments in ratio, i.e.  1:4, 2:3, 3 :2, 4:1, farmland  ecotype only and mining ecotype only, and the soil spiked with 10 mg•kg^-1 cadmium, was conducted. Results demonstrate that as compared with their respective  treatments of  monoculture interplantation increased  the farmland ecotype  of B.  pilosa  bio?mass, but decreased the mining  ecotype of B. pilosa in biomass per plant, and significantly  increased the contents of chlorophyll a, chlorophyll b  and carotenoid in the two  ecotypes of B. pilosa,  and the concentration of  cadmium in various  or gans of the  two ecotypes of B. pilosa.  When the  interplantation ratio was 2:3  (farmland ecotype:mining ecotype),thecontent of cadmium was  the highest in all  organs of the  two ecotypes of  B. pilosa, and  the cadmium accumulation  in theshoots and the whole  plant in one pot  were also the highest, reaching up  to 422.08  and 477.91  μg•pot^-1  , respectively.To sum up, the interplantation of the two ecotypes of  B. pilosa at a ratio of 2 : 3  (farmland ecotype ∶  mining ecotype) may effectively improve the plants′ cadmium accumulation capacity, and consequently  the effect of the two ecotypes of B. pilosa remedying cadmium contaminated soils.

A pot experiment was conducted to study effects of Citric acid (CA) and EDTA on physiological characteristics and Cd accumulation of R. communis. Results show that the application of EDTA alone significantly reduced the biomass of shoots and the content of chlorophyll of R. communis, evidently affected the activity of antioxidant enzyme in leaves of the plant(P<0.05), and even inhibited the activities of SOD and POD, when the application rate reached 10 mmol•kg-1. The application of EDTA and CA together reduced the toxicity of EDTA to R.communis to a certain extent, the effect of EDTA, at 1 or 5 mmol•kg^-1, lowering the biomass of shoots and the content of chlorophyll of R.communis and the effect of EDTA, at 1 mmol•kg^-1, increasing the content of MDA in the plant. The application of EDTA alone, at 5 mmol•kg-1, brought Cd accumulation and transfer capacity of the plant to the peak, two times as high as in CK. However, once 2 mmol•kg^-1CA was applied in combination, the effect of EDTA reached a new peak, 3 times as high as in CK. Therefore, combined application of EDTA with Ca should be a practice of great potential in enhancing the effect of R.communis remedying Cd polluted soils.

Jatropha curcas L. is a kind of tree that can be used as raw material for production of bio-energy, and hence called bio-diesel tree. As it is also quite high in tolerance to environmental stresses, it can be used as pioneer plant in restoring vegetation in ecologically fragile environment and in phyto-remedying polluted soils as well, therefore, planting this kind of trees may achieve the win-win goal in both energy and environment. An indoor pot experiment was carried out to explore effects of concentration of heavy metal nickel (Ni) (0,500 and 1 000 mg kg^-1) on photosynthetic properties, morphological characteristics and water utilization of Jatropha curcas L. and mechanisms of the plant regulating its growth and utilizing efficiently soil water, while adapting to Ni-polluted soils. Results show that plant height growth rate, and breast-height diameter growth rate, diurnal variation of net photosynthetic rate (P_n), diurnal variation of transpiration rate (R_t), robust seedling index, Huber value, and irrigation water utilization efficiency (W_i,u,e) were all decreased significantly (P < 0.05), while leaf water utilization efficiency (E_w,u) and soil moisture content in root-zone of the plant increased with increasing nickel concentration. Compared with CK(Ni0),Treatment Ni1 did not have much effect on stomatal conductance (Gs) of plants(P>0.05), but Treatment Ni2 did (P<0.05). As nickel contamination significantly reduced Rt of Jatropha curcas L., and affected the plant’s water transport capacity from roots to shoots and its capacity of water supply to leaves per cross-sectional area of sapwood, it significantly reduced E_i,w,u, of the plant and eventually total dry mass of the plant. However, it is worth noting that by increasing its E_i,_w,u of leaves to significantly mitigate the water stress caused by reduced transpiration rate, the tree is able to grow in Ni-polluted soils. In this experiment, the highest concentration of nickel in the soil still conducive to growth of Jatropha curcas L. was up to 500 mg kg^-1.

Three arsenic-resistant strains of fungi were isolated and identified as Chaetomiumglobosum, Alternaria tenuissima and Scheffersomyces stipitis from arsenic contaminated soils, and tested for tolerance of the strains to As and effects of the treatment of As-contaminated soils with the strains on soil As bio-availability relative to duration of the exposure to and inoculation rate of the fungi. Results show that the three strains were quite good in tolerance to As⁵⁺ in the range of 5-100 mg•L^-1 As⁵⁺ and displayed an order of Scheffersomyces stipitis > Alternaria tenuissima > Chaetomium globosum. When As concentration was in the range of 5-10 mg•L^-1, Scheffersomyces stipitis was somewhat promoted in growth. Within the first 30 days of the inoculation of the three strains, soil bio?available As increased by 137.2, 77.9 and 36.5 times, respectively, as compared with CK. Their effects on soil As varied with their inoculation rate, displaying a rising trend with the rate and a positive relationship.

Dimethyl phthalate (DMP), a kind of toxic organic compound ubiquitous in the environment, has been listed as an environmental pollutant for priority control by the Ministry of Environmental Protection of China (MEP). The purpose of this study is to explore impacts of DMP contamination (0-40 mg•kg^-1) on microflora, functional groups and diversity of soil microbes in black soil. Results show that the populations of bacteria and actinomyces in the black soil were inhibited by DMP contamination and the impact was positively related to concentration of the pollutant. However, the amount of fungi in the soil was promoted and the effect increased with rising DMP concentration. Functional bacteria, like nitrogen fixing bacteria, ammonia oxidizing bacteria, nitrite-oxidizing bacteria, organic phosphorus-dissolving bacteria and inorganic phosphorus-dissolving bacteria, were all inhibited by DMP contamination, but iron bacteria were promoted by DMP contamination. DMP contamination decreased richness and Shannon-Wiener index of the soil microbes in the black soil and the negative impacts lasted for more than 25 d, in the treatments with concentration of the pollutant being 10, 20 and 40 mg•kg^-1. All the findings indicate that DMP in the range of 5-40 mg•kg^-1 in concentration may affect structure of the soil microflora and populations of functional groups and biodiversity of the flora, and hence functions of the black soil ecosystem.

By following the guideline (GB/T 27859—2011) of “Spiking Sediment in Toxicity Test on Chironomus tepperi in Sediment?Water System”, tests were carried out using mortality, emergence rate, growth rate, time for emerging, sex ratio, and yield of eggrafts and hatchability as observation targets to study chronic toxic effect of spinosad residue in sediment on larvae and eggrafts of Chironomus tepperi. It was found that growth rate of larvae and average time for female adults to emerge were positively related to spinosad concentration spiked, while survival rate and emergence rate were negatively related and average time for male adults to emerge and sex ratio of adults were not related. The tests indicate that the 28 d LC₅₀ of spinosad for Chironomus tepperi was 1 626.96 μg•kg^-1, and the EC₅₀ (half maximal effective concentration) on emergence was 1 633.53 μg•kg^-1. When the concentrations of spiked spinosad were lower than 10 μg•kg^-1, advanced emergence and higher growth rate of Chironomus tepperi could be observed as compared with the control. Eggraft yield of Chironomus tepperi was not significantly affected by spinosad in the sediment, while the number of eggs in each eggraft and the number of first-instar larvaes hatched was significantly affected.

A study was carried out in order to investigate differences between six ecotypes of vetiver grasses (Karnataka,Sunshine, Huffman, Kandy, Monto and Veriveria nermorlis)in photosynthetic physiology and rules of diurnal variation of photosynthetic parameters. Results show that the six ecotypes of vetiver grasses varied sharply in light saturation point (LSP), light compensation point (LCP), maximum net photosynthetic rate (P_n,max), dark respiration rate (R_d) and diurnal variation of net photosynthetic rates (P_n). Among the six ecotypes, Karnataka and Veriveria nermorlis were higher in LSP, LCP and P_n,max; Sunshine and Kandy, lower in LSP; Sunshine and Huffman, lowest in LCP;Monto, lowest in P_n,max; Karnataka, higher in R_d; and Huffman, lower in R_d. Furthermore, the diurnal variations of P_n of Karnataka and Veriveria nermorlis both could be depicted as two single-peak curves with P_n,max appearing at 12:00, while the diurnal variations of P_n of the other four ecotypes, as double-peak curves with an obvious midday depression appearing at 12:00. Relationships of P_n with ecological factors, such as air temperature (T_a), air CO₂ concentration (C_a), relative air humidity (H_R) and photosynthetically active radiation (PAR), were analyzed by correlation, path and decision coefficients, respectively, indicating that PAR is the primary determining factor for P_n of the six ecotypes of vetiver grasses, H_R, the main limiting factor for P_n of Karnataka, Huffman, Monto and Veriveria nermorlis, and T_a the main limiting factor for Pn of Sunshine and Kandy.