As a member of the footprint family, material footprint (MF) signifies the total of raw materials excavated and used to satisfy the need of an economic entity and is used as a measurement in reallocation of natural resources of the raw material and an integrated index of resource consumption and environment pressure. The economic system material flow method is the basis for calculation of material footprint. Although quite a volume of researches have been reported on calculation of material flow in China, little is available in the literature about material footprint. The domestic technology-based assumption of I/O model (DTAIO), mixed life-cycle inventory I/O model (LCI-IO) and multi-regional input-output model (MRIO) are the I/O-based methods commonly used in budgeting material footprint, among which, the last one is relatively more effective. The researches on material footprint are focused mainly on using a nation as the unit for regional calculation, and researches using state or province as the unit are rarely reported, let alone researches on budgeting of regional material footprint in China. Now the multi-regional I/O inventories are being established, making it feasible to do researches on regional material footprint in China.

Worldwide concerns have arisen over the potential endocrine disrupting effects of synthetic chemicals on the endocrine system of wildlife and human. Strategies for environmental management of endocrine disrupting chemicals (EDCs) adopted by the U. S. Environmental Protection Agency, the European Union, the Ministry of Environment of Japan, the Organization for Economic Cooperation and Development, the World Health Organization and the United Nations Environment Program, and their progresses were reviewed and summarized. It was found that they had worked out national implementation plans for EDCs, established strategies for testing and assessment and criteria for identification of EDCs, developed and validated a large number of testing methods, adapted and amended relevant laws and regulations for EDCs management, respectively, in the light of their own specific situations. Based on the current situation of EDCs management in China and progresses in researches of this field abroad, some suggestions on strategies for EDCs environmental management were hereby brought forth.

In recent years, volatile organic compounds (VOCs) of precursor of photochemical smog and the key factors of the formation of hazy weather have aroused extensive concerns among scholars both at home and abroad. This is a review retrospecting and summarizing researches on source and sink, monitoring technology and pollution characteristics of atmospheric VOCs, in China. The review began with generalizing the source and sink of VOCs, including natural and anthropogenic sources of VOCs and main paths of removing the substances. Then the review went on discussing VOCs monitoring techniques used at home and abroad, analyzing and summarizing existing relevant environmental management standards and technical specifications in China, and collating and comparing VOCs pollution characteristics in typical urban atmospheres in recent years. From the aspects of species of VOCs detected, their concentration release levels and sources of releases, atmospheric VOCs pollution levels of various regions were evaluated, providing certain scientific basis for protection and pollution prevention of the atmospheric environment. In the end, based on the summarization of the current research progresses, some main problems existing in the current studies are pointed out and future directions and development are prospected.

Based on the eddy covariance system, variation of CO₂ flux of the alpine wetland ecosystem of Kobresia tibetica wet meadow in Lake Qinghai was characterized and its affecting factors analyzed. Results show that CO₂ flux in the ecosystem exhibits obvious characteristics of diurnal variation and monthly variation. During the vegetation growing season, net absorption of CO₂ was observed, with absorption peaks appearing between 12:30 and 15:00 daily, and the highest one reaching up to 0.42 mg·m^-2·s^-1, while net emission peaks appeared between 20:00 and 22:30, with the highest one being 0.24 mg·m^-2·s^-1. During the non-growing season, CO₂ flux varied slightly and was dominated with net emissions. In all the months of the non-growing season, except for November, CO₂ emissions were obviously higher in the day than in the night. The annual net ecosystem CO₂ exchange rate of 2015 was 54.55 g·m^-2 in the wet meadow wetland ecosystem, which obviously behaved as a carbon source. CO₂ emission path analysis shows that soil temperature, photosynthetically active radiation and saturated vapor pressure difference were the main factors controlling CO₂ flux in the ecosystem.

To combine planting with breeding is an important approach to recycling livestock and poultry manure, preventing and controlling the waste from polluting the environment and reducing the use of chemical fertilizers in farmland. During the period from 2001 to 2013, nitrogen and phosphorus surpluses were found universally in farmlands of Jiangsu Province, and might be divided generally into two phases in intensity, i.e. rising first and then falling. The surplus intensity was commonly higher in the northern part than in the central and southern parts of the province. Excessive input of fertilizer was the main driving factor of the surplus. Compared with the year of 2001, the year of 3013 witnessed a sharp drop in nitrogen and phosphorus surplus intensity in most parts of the province, and great changes took place in budgeting of farmland nitrogen and phosphorus all over the province. Logistic model was used to analyze factors affecting willingness of livestock farms to combine breeding with planting willingness. It was found that subsidies in the name of environmental protection policy, pressure of the supervision of the environmental protection department, breeding scale and supporting land area, etc. are major factors affecting their willingness.

Studying gene flow of transgenic wheat helps establish a corresponding strategy to prevent transgene escape and germplasm contamination between compatible wheat genotypes. An experiment was carried out using transgenic wheat with resistance to wheat yellow mosaic virus (WYMV) as pollen donor, and Yangmai 158 and dwarf male-sterile wheat as pollen receptors, and two plots of the transgenic wheat, different in size (100 and 400 m²) and laid out in parallel as pollen sources. Gene flow frequency was monitored at different intervals from the pollen source to investigate effects of size of the pollen source and competition between pollens on gene flow of the transgenic wheat. Results show that size of the pollen source did not significantly affect transgene flow frequency, but variety of the two pollen receptors did. The male-sterile dwarf wheat was found to be significantly higher in transgene flow frequency at distance intervals of 0 and 2 m from the pollen source. The gene flow frequency of transgenic wheat declined dramatically with increasing distance from the source and was reduced to 0 over the test distance of 5 m. All the findings indicate that pollen competition may be a major factor influencing transgene flow and isolation by distance is one of the most effective methods to control pollen-mediated gene flow in wheat.

Aiming at the restraining factors of and the main threats to suitability of the black-necked crane habitats in the Black-necked Cranes National Nature Reserve in the valley of the mid-stream of the Yarlung Zangbo River, based on the indices, such as habitat suitability, conservation ratio, conservation efficiency and so on, suitability and conservation status of the black-necked crane habitats at their third stage in Shigatse, the Black-necked Cranes National Nature Reserve in the valley of the midstream of the Yarlung Zangbo River was analyzed and evaluated. Results show that the sum in area of the habitats suitable and near-suitable to black-necked cranes accounted for 31.05%, 32.00% and 41.00% of the total of the reserve, respectively, in 1994, 2005 and 2015, indicating that their living space was increasing steadily. The comparison between 1994 and 2015 in conversation ratio and conservation efficiency shows that the distribution of habitats suitable for foraging and night-roosting tended to get flocked towards the core area and so did the habitats near-suitable for foraging. Moreover, the programming of the reserve for conservation of habitats suitable for foraging and night-roosting decreased in rationality, while that for conservation of habitats near-suitable to foraging increased. In view of the ratios of various habitats under protection in the epitaxial areas, there seem to be vast tracts of habitats available to black-necked cranes, which, however, have not yet been included in the scope for protection.

On the basis of the traditional system of horizontal subsurface flow constructed wetland (SSFW), a new system, namely, inserted ecological filter bed (IEF), was developed. Comparison was made between the two systems in pollutant removing effect in different seasons. Results show that IEF was higher than SSFW in pollutant removing rate and removed total nitrogen (TN), ammonia nitrogen (NH₃-N), total phosphorus (TP) and permanganate index (COD_Mn) by 63.6%, 78.4%, 64.7% and 51.9%, respectively, on average, during the entire experiment period, which was 13.1%, 6.9%, 12.1% and 7.3%, respectively, higher than what the latter did. Temperature was an important factor affecting pollutant removing rate of SSFW. The rate dropped significantly during the fourth season (Oct. to Dec.) of a year when temperature is low, while IEF still maintained a relative high pollutant removing efficiency in winter, removing TN, NH₃-N, TP and COD_Mn by 57.9%, 63.0%, 58.7% and 51.8%, respectively, which was 12.8%, 11.1%, 10.2% and 7.2%, higher than what SSFW did, respectively. All the findings in this experiment indicate that IEF can solve the problem of SSFW being low in pollutant removing efficiency in the low-temperature season, and has certain important significance in guiding purification of heavily polluted rivers.

Biochar has emerged as an important green environmental sorbent of great potential in in-situ remedying contaminated soils and water. However, little is known regarding how biochar mitigates potential ecotoxicity risks of the pollutants in the environment through interaction with the pollutants. To evaluate the effects of biochar on ecological toxicity of cadmium (Cd), a heavy metal element, in sediments, Cd bioaccumulation, DNA damage, superoxide dismutase (SOD) activities and malondialdehyde (MDA) levels in the hepatopancreas of benthic macroinvertebrate Bellamya aeruginosa following 14-day exposure to sediments spiked with Cd and/or activated-sludge-derived biochar were investigated. Results show that activated-sludge-derived biochar significantly reduced Cd content in porewater. In the treatments relatively low in Cd concentration (10 μg·g^-1), the addition of biochar did not significantly reduce Cd bioaccumulation, while in the treatments relatively high in Cd concentration (50 μg·g^-1), the addition of only 5% of biochar was enough to significantly reduce Cd accumulation. The applied activated-sludge-derived biochar was not toxic to B. aeruginosa. In the treatments spiked with 10 μg·g^-1, no effect of biochar affecting DNA damage index, SOD activities, and MDA contents in the hepatopancreas was observed, indicating the addition of biochar in sediments low in Cd content did not mitigate Cd toxicity. In the treatments spiked with 50 μg·g^-1, the addition of 1% biochar did not show any effect on Cd toxicity, either, however, the addition of 5% biochar significantly alleviated DNA damage, increased SOD activity, lowered MDA levels, and estimatedly reduced Cd toxicity by about 60%. It could, therefore, be concluded that reduced bioavailability of Cd in sediments does not invariably lead to decreased bioaccumulation in B. aeruginosa. The application of biochar at a high rate in sediments may reduce Cd bioaccumulation and hence Cd toxicity to some extent through inhibiting Cd adsorption. The effects of biochar alleviating ecotoxicity of pollutants in sediments may possibly be related to type and concentration of the pollutant and amendment rate of biochar.

As contaminated-soil samples were prepared artificially with As concentration being 100 mg·kg^-1 for the study on the use of FeCl₃-citric acid, a compound leachate prepared by means of ultrasonic dissolution, to leach As from As contaminated soils and effects of ratio, pH, temperature of the leachate and commonly coexisting anions or cations (Ca²⁺, Al³⁺, SO₄^2- and PO₄^3-) on leaching characteristics and their mechanisms. Results show that in solutions the same in soil-to-liquid ratio (1:10), the compound leachate maximized its effect of leaching As from As-contaminated soils when its m(FeCl₃):m(citric acid) was 3:1 and was better than simple leachates in leaching effect. Rising pH and temperature within a certain range contributed to leaching. In solutions with pH being 7, 8, 9 or 10 and temperature at 25, 35 or 45℃, the leaching kinetics could be better described with the Elovich equation, which indicates that the leaching of As with FeCl₃-citric acid from As³⁺ contaminated soil is a heterogeneous diffusion process. The coexisting ions, such as Ca²⁺, Al³⁺, SO₄^2- and PO₄^3-, 0.01~0.2 mol·L^-1 in concentration also had certain impacts on leaching of As. The higher the concentrations of the other coexisting ions, except for SO₄^2-, the better the leaching effect. The compound leachate is expected to have a bright prospect for its application thanks to its low cost and wide availability.

To investigate plant rhizospheric effects on biodegradation of chlorobenzene compounds in constructed wetlands, Phragmites australis and Typha angustifolia, two typical wetland plants, were selected and planted in a simulated outdoor constructed wetland mesocosm to explore changes in population of soil microbe and activity of soil enzyme in the rhizosphere of the plants under stress of hexachlorobenzene. Results show that both P. australis and T. angustifolia significantly affected soil microbe (bacteria, fungi and actinomycetes) in population and soil enzymes[dehydrogenase (DEH), catalase (CAT) and polyphenol oxidase (PPO)], in activity in the rhizosphere, which were all higher than in the non-rhizosphere soils, and the rhizosphere effects of T. angustifolia were higher than those of P. australis (P<0.05). Population of the soil microbe and activities of the soil enzymes were found negatively related to concentration of HCB in the rhizospheres of P. australis and T. angustifolia,and particularly to the activities of DEH and PPO in the rhizospheres of T. angustifolia(P<0.01). The rhizospheric effects of the two plants increased with the increase in microbial population and enzyme activity in the rhizospheres of the plants, which in turn helps remove HCB in the wetland ecosystem.

Screening of appropriate species of pioneer plants is crucial to phytoremediation of gold tailings. In order to screen suitable species of pioneer plants for gold mine tailings, eleven species of plants, including leguminous, gramineous and ornamental plants, were selected for the test. In the test, composted sewage sludge was amended in the field of gold tailings to assist the plants in setting-up and growing and then its effects on growth of the plants and changes in content of available nutrients in the field were monitored. Results show that among the 11 species of plants tested, erect milkvetch(Astragalus adsurgens), ryegrass (Lollum multiflorum), tall fescue (Festuca arundinacea) and sedum spectabile (Sedum spectabile) were found higher in emergence rate and survival rate, better in growth and larger in biomass, so the four species of plants could be used as pioneer plants for phytoremediation of fields of mine tailings. Besides, applying composted sewage sludge was beneficial to plant growth, accumulation of plant biomass and supply of available nutrient, but did have certain inhibitive effect on emergence of plant seedlings.