In recent years, the eco-environmental situations in the country are getting severer, with the degradation of ecosystem functions posing a prominent problem, which is threatening ecological security and restraining economic and social development of relevant regions to a certain degree. Therefore, ecological restoration has become an issue attracting high attention. However, the current restoration pays too much attention to revegetation rather than function, to means rather than effects, and to parts rather than whole regions in processes. In view of the problems, the following concept and connotation of regional ecological regulation and restoration centered on "Decreasing Pressures on Environmental Resources and Increasing Efficiency of Ecosystem Functions" are put forward. The restoration of regional ecosystems should combine ecological projects with eco-societal regulation, instead of depending on ecological projects as its means; focus on large-scaled regions exposed to potential pressure, not just on local areas suffering severe ecological problems or damage; adopt a variety of means to reduce overall ecosystem pressure, improve regional ecological functions, and aim at ecological, economic and social benefits holistically, rather than satisfaction with revegetation. On such a basis, framework of approaches of regional ecological regulation and restoration was built up, and a technical flowchart plotted, encompassing the following five technical processes, i.e. problem recognition, diagnostic analysis, model construction, efficiency analysis and demonstration application, in an attempt to realize regionalization, perpetuation and benefit-maximization of ecological restoration.

Zoning for eco-remediation is the precondition for scientific and efficient development of ecological restoration. Zoning was performed of Balin Right Banner in Inner Mongolia of China, an important section of the Horqin Steppe and an ecologically sensitive and fragile area as well. In zoning, an approach combining "bottom-up analysis" with "top-down parsing" was adopted and the technology of GIS spatial analysis was applied. Based on the rule of spatial differentiation of dominant ecological functions, zoning was done with ecological degradation degree, meteorological characteristics, terrain, landform and vegetation of the region taken comprehensively into full account. The first level zoning was done in the light of terrain and type of vegetation cover, to form zonal environment dominated ecological type groups; the second level zoning was by dominant ecological function, such as water source reservation, wind breaking and sand fixation, water erosion prevention and biodiversity conservation, to form mid-scaled zonal environment dominated ecological function type group; and the third level zoning was by degradation degree, i. e. non-degraded, slightly-degraded, moderately-degraded and severely-degraded, to form three groups of subzones different in toughness of the remediation, i. e. subzones for preventive eco-remediation, subzones for adjustable eco-remediation and subzones for key eco-remediation. The Balin Right Banner was divided into 3 first-grade zones, 7 second-grade zones and 29 third-grade zones which not only embodied the rule of dominant ecological function differentiation, but also made the remediation pointed and provided technical support to developing zone- or subzone-specific control measures and ecological remediation programs, such as rearrangement of vegetation, adjustment of industrial structure, etc.

To explore effects of vegetation restoration on soil properties in sandy land, soil samples were collected, separately, from 4 plots of land under Prunus sibirica (SX), Caragana korshinskii (NT), Salix gordejevii (HL), and natural grasses (CD) in Duolun County in Inner Mongolia for analysis of soil physical and chemical properties, such as content of soil water, pH, EC, SOC, total N, total P. Results show:(1) SOC is always the highest in the surface layer, regardless of plots, reaching 21.3, 11.0, 7.3 and 2.0 g·kg^-1 in Plots SX, CD, NT and HL, respectively; (2) Total P, total N and SOC varied similarly in content; (3) The content of soil fine clay in Plot SX is the highest, reaching 26.5%, that in Plot CD, the second, being 10.8%, and that in Plot HL the least, being just 6.5%; (4) In the 0-10 cm soil layer, SOC is significantly or ultra-significantly related to TN, TP and soil water in content, and the content of fine clay is almost significantly related to all soil nutrient indices (P<0.05 or P<0.01). All the findings in this research demonstrate that, large-scale cultivation of Salix gordejevii in recent years is not ideal in improving physical and chemical properties of the sandy soil in the studied region, however, naturally developed grasslands have much better effect. Therefore, it is wise to pay more attention to protection of natural grasslands, when trying to control desertification by revegetation.

Restoring vegetation is the main approach to remediation of the global ecosystem. In China, the large scale vegetation rehabilitation activities are distinctive ecological measures, which have brought about enormous benefits and wide implications for the ecological remediation process. As a typical example of the great vegetation rehabilitation programs, the "Grain for Green Program" (GFGP) was initiated and experimented in the Loess Plateau as demonstration, and extrapolated nationwide. Since the implementation of GFGP, how the vegetation restoration was going on and what its implications were have become a hot spot in the academic circle. Implementations of the GFGP in Yan'an and Yulin Cities of Shaanxi Province, and Lüliang and Linfen Cities of Shanxi Province, typical areas of the Loess Plateau, were surveyed and changes in land use analyzed. Based on the data of annual mean vegetation coverage in 2000-2014, spatio-temporal changes of the vegetation were characterized. On such a basis, ecosystem services, such as soil conservation service, hydrological regulation service and vegetation carbon sequestration service in these typical areas were evaluated quantitatively, using soil erosion rate, surface vegetation evapotranspiration (ET) and vegetation net primary productivity (NPP) as indexes, so as to analyze effects of the vegetation restoration on major ecosystem services. Results show:(1) The areas of forests and grasslands have increased significantly since the implementation of GFGP; (2) These areas as a whole improved significantly in vegetation coverage with the years passing on. The area of newly restored vegetation accounted for 5.8%, 49.1% and 79.0% in 2000-2005, 2000-2010 and 2000-2014, respectively; (3) The soil conservation service strengthened, thus reducing the soil erosion rate by 17.5% from 1 162.6 t·km^-2·a^-1 in 2000 to 959.6 t·km^-2·a^-1 in 2014 and the area of moderate erosion by 53.7%, and keeping the soil conservation rate well above 84% and on a fluctuating and rising trend; (4) The hydrological regulation service improvement. The area with increased ET reached 48 094.1 km², or 39.6% of the total land area of the four cities; and (5) The carbon sequestration service heightened, with NPP generally on a rising trend. The areas with significantly increased NPP accounted for 60.3% of the total land area of the four cities. Total carbon sequestration increased by 45.4% from 39.2 Tg in 2000 to 57.0 Tg in 2014. This study revealed that the implementation of GFGP has significantly improved the vegetation in the studied areas, thus greatly strengthening ecosystem services in the region. Spatio-temporal variation of vegetation restoration and its effects on ecosystem service should draw more attention from both scientists and decision makers.

Seed bank plays an important role in remedying degraded grasslands and restoring vegetation therein. A seed bank reactivation technology was developed for sandy grasslands to address the problem of desertification of the grassland ecological function zone of the well-known Horqin Steppe. The technology begins with enclosing a tract of grassland as seed bank and then applies a kind of water-retaining fertilizer, a mixture of organic manure and water retention agent, into the tract of grassland, rapidly making the soil moist and fertile. Results show that application of the technology to the degraded grassland, increased its vegetation coverage by 66.43%, Shannon-Wiener diversity index by 8.90%; soil organic matter, total nitrogen, total potassium and total phosphorus in the 0-30 cm soil layer by 23.47%, 14.82%, 2.90% and 403.56%, respectively. Therefore, it can be concluded that the technology is conducive to improvement of soil fertility and species diversity of the plant community in a short period of time, restoration of the vegetation and control and fixation of mobile sand.

The study to evaluate regional ecosystem services and their radiation effects may help exposit the features of integrity and correlativity of the ecological-economical-societal complex system of the studied region. Based on the 2013 land-sate remote-sensing images of the Zhangjiakou-Chengde Region and the eco-service valuation method, the composition of the surface land cover and key ecosystem services of the region and their radiation effects on Beijing have been analyzed and evaluated. Results show that about 97% of the land in this region is covered with forests, grasslands and farmlands, which are the mainstay of the ecological protective screen for the Beijing-Tianjin-Hebei Metropolitan Region. The natural ecosystem of the region may provide key ecosystem services, such as water conservation, wind and sand control, carbon sequestration and oxygen release, valuated as high as 189.5 billion yuan RMB in 2013. The high-valued eco-zones are distributed mainly in Chengde, of which the land is mostly covered with forests and grasslands and the southeastern part of Zhangjiakou. Every year, nearly 21% of the key ecosystem services of the Zhangjiakou-Chengde region may render are radiated into Beijing, via water and wind. Within the region, Huailai, Chicheng, Xuanhua, Zhuolu, Chongli and Guyuan counties are more closely related to the ecosystem services of Beijing as major contributors. All the findings of the study may serve as certain valuable reference for future efforts to exposit ecosystem integrity of the Beijing-Tianjin-Hebei Metropolitan Region and to explore scientific mechanisms for eco-remediation and cooperation of the Region.

Analysis for prediction of future scenarios of land use in rural areas and reasonable scales of land use for rural settlements is the foundation for excavating the potential of land integration and optimizing the spatial pattern of rural land use. A case study of Yucheng of Shandong Province was performed to explore reasonable scales of land use for rural settlement in the future scenario of farming becoming a part-time job for most farmers from the aspect of optimization of the ratio of cultivated land to residential land. Results show:(1) The farming income is a major factor affecting the income of a farm household, and to predict a reasonable scale of land use for rural settlement, it is necessary to take into account comprehensively the scale of cultivated land in the region studied; (2) The current ratio of cultivated land to residential land in Yucheng is quite low or 3.9 on average and about 75% of the villages lingered in the range of 2-6, which indicates that it is essential or critical to raise or optimize the ratio; (3) In the future scenario of farming becoming a part-time job and its in-depth development, the reasonable ratios of cultivated land to residential land will be 9.95 and 15.99, respectively, and the reasonable scale of land use for rural settlement in Yucheng will be 6 638 and 4 278 hm², respectively, with the potential of reclaiming 8 121 and 10 481 hm² of vacated residential land; And (4) the study predicted that the realignment of rural settlements may expand the farmland by 55.02%-71.01% in Yucheng in 2020, but in reality, the potential depends by a large margin on development of urbanization and the strength of reformation of the land policy in the future.

To study the dynamic mutually-promoting and restraining relationships of regional environment with urbanization and industrialization, a regional relative environmental load index model with the pollutant discharge intensity in the reference area set as reference point was built up, using the comparative analysis method, a comprehensive evaluation program formulated, and criteria for judging whether or not a regional environment was safe proposed. Based on empirical analysis of the environmental load of Dalian during 2000-2012, prediction was made of responses of the environmental load in Dalian and China in 2025, by taking into account the national economic and social development programs and the goals of related environmental protection programs of the country and the city. Results show that with the living standard of the residents and the pollution controlling technical level growing steadily, the threshold of environmental load in Dalian on the whole ascended; the discharge of the three types of domestic waste aggravated the regional environmental load, and the discharge of the three types of industrial waste did not show much negative influence on the regional environmental load; the population-environment load index declined first and then turned back upwards, exhibiting an aggravating trend, while the industry-environment load index remained quite stable with a slight decline. It is predicted that the environment system in the region will remain in the blue alert state or at a relatively safe level after 2016, while the system load will decline at a gradually slower rate. Therefore, it's necessary to control the speed of urbanization timely and reasonably.

Small-sized private livestock farms in the rural areas discharge quite a large volume of livestock wastes, contributing significantly to the agricultural non-point source pollution. As the farms are widely scattered in distribution, it is very hard and costly to exercise overall environmental supervision and pollution control. And what is more, so far no effective livestock waste treatment technologies or policies are available for extension. In recent years, a waste recycling pattern of pigsty-biogas digester-orchard has become an effective way to alleviate livestock waste pollution. However, this pattern depends mainly on government subsidies, which in turn leads to low efficiency of government financial funds. The public-private-partnership (PPP), as a new financing mechanism, has been developing the fastest in public services supply, and mainly applied to the construction of large-scale infrastructure, rather than such small projects as livestock waste treatment or transfer. In light of the above, this paper aims to explore whether or not PPP can be introduced into small-scale farms' livestock waste transfer projects. A case study was carried out of the PPP model demonstration in Pujiang County. Through cost-benefit analysis of the Pujiang case, economic feasibility of the PPP project of handling and treating livestock waste from small-sized livestock farms and environmental benefits it may create were discussed. Suggestions on improving the PPP system for small-scale projects are brought forth, in anticipation of initiating innovative thoughts for comprehensive utilization of livestock wastes from small scaled livestock farms.

In order to comprehensively evaluate pollution of the Huizhou section of the Dongjiang River, concentrations of seven heavy metals (Cu, Zn, Mn, Ni, Pb, Cr and Hg) in the muscle of commercial fish typical of the Huizhou Section of the Dongjiang River were determined. Pollution degree and food safety of the fish were evaluated with the single factor pollution index method, comprehensive pollution index method and target hazard quotient method. Results show that Cu, Zn, Mn, Ni, Pb, Cr and Hg in the fish varied in the range of 0.058 1-0.546, 1.90-14.46, 0.225-1.69, 0.000 4-0.045 8, 0.039 7-0.148, 0.002 7-0.115 and 0.002 1-0.075 7 mg·kg^-1, respectively, in concentration, and averaged 0.185, 5.54, 0.670, 0.011 4, 0.065 5, 0.052 3 and 0.022 5 mg·kg^-1, respectively. None of the averages exceeded the limits specified in the National Standards for Consumption of Aquatic Products. Compared with commercial fishes in other places, either domestic or foreign, the fish in the section of the Dongjiang River, were relatively low in heavy metal contamination level. The evaluation with the single factor pollution index and comprehensive pollution index method shows that all the fishes in the section could be sorted into the category of "clean", with single factor and composite health risk indices being both <1, which indicates that the fish in the Huizhou Section of the Dongjiang River are safe to eat, and pose no health risk to consumers.

To explore effects of combined heavy metal pollution on aquatic organisms, an experiment was carried out using fresh water rotifers, Brachionus calyciflorus, which are among the most important groups of zooplankton in terms of biomass, ecological importance and bio-diversity, and are recognized as ideal bioassay animals for toxicity tests because of their small size, short generation time and rapid reproduction rate. However, few reports are available in the literature on impacts of combined heavy metal pollution on rotifers. This experiment was designed to use solutions of heavy metal mixture, containing Cu²⁺ (0.001 and 0.01 mg·L^-1), Zn²⁺ (0.01 and 0.1 mg·L^-1), Cd²⁺ (0.01 and 0.1 mg·L^-1), Cr⁶⁺ (0.01 and 0.1 mg·L^-1), Mn²⁺ (0.1 and 1 mg·L^-1) and 18 d old freshwater rotifers in the cumulative culture test. Population growth rate and maximal population density of the rotifers were monitored. Results show that concentrations of the metals in the solution was the major factor affecting toxicity of the solution to the rotifers. Population growth rate and maximal population density of the rotifers were significantly lowered by solutions high in heavy metal concentration. Interactions of any given element with the other 4 in concentration in the solution all significantly influenced population growth rate of the rotifers, while interactions of Zn²⁺ with the other 4 in concentration in the solution significantly influenced maximal population density of the rotifers. The rotifers were more sensitive to interactions between the elements in the solution in population growth rate than in maximal population density. So they can be used as bio-indicator to monitor combined heavy metals pollution of water bodies.

Livestock wastewater falls into the category of wastewater with a high concentration of organic pollutants and hence poses a threat to the environment when disposed inappropriately. Ozonation is known as an attractive alternative to treat the wastewater. An experiment was carried out to explore effect of ozonation on concentration and composition of the organic pollutants relative to concentration of ozone and effect of the treatment of ozonation combined with cultivation of Vallisneria natans removing organic pollutants from livestock wastewater. Results show that when exposed to ozone at a rate of 10(AO1), 30(AO2) and 50 mg·L^-1(AO3) for 30 min, piggery wastewater was lowered by 15.6%, 17.6% and 29.4%, respectively, in UV₂₅₄ and by 12.2%, 7.6% and 22.0%, respectively, in UV₄₃₆ and increased by 13.9%, 16.7% and 39.4%, respectively, in DOC/UV₂₅₄. The treatment of ozonation in combination with cultivation of Vallisneria natans for 4 weeks had the wastewater lowered in by 8.5%-17.6%, 16.2%-35.3% and 12.9%-21.8% in DOC content, UV₂₅₄ and UV₄₃₆, respectively. Obviously ozonation could trigger transformation of the semi volatile organic compounds in the piggery wastewater. All the findings of this experiment indicate that when properly applied, this treatment method can be used to pretreat livestock wastewater before it is discharged, and to promote biodegradability and degrading rate of organic pollutants in the wastewater.

Phosphorus adsorption capacities of 8 types of natural clay laterites and treated (roasted or spiked with natural minerals) clay laterites in phosphorus-polluted water were investigated in a simulation experiment and mechanisms of the laterites adsorbing phosphorus explored through isothermal adsorption. Results show that all the 8 types of natural clay laterites were more or less able to adsorb phosphorus in water, but they varied in performance in waters different in pollution degree. The clay laterite from Jiangxi province was the highest in P removal efficiency in wastewaters of Grade V or Grade V on the lower side. The Freundlich equation fitted well with phosphate adsorption isothermal curves of the natural clay laterites in terms of R² value, which indicates that the adsorption was in the form of inhomogeneous multi-molecular-layer adsorption. In wastewater with the initial phosphorus concentration reaching 200 mg·L^-1, the natural lay laterites might adsorb as much as 2.38 mg·g^-1 phosphorus. Roasting or baking significantly enhanced the soils' phosphate adsorption capacity. Spiking natural minerals did not have much effect on phosphorus adsorption capacity of the soils, but could effectively neutralize acidity of the effluents. All the findings demonstrate that clay laterites can be used potentially as adsorbent to purify phosphorus-polluted wastewater, and different processing methods should be adopted to improve P adsorption and wastewater purification efficiency of the materials.