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141.
The reestablisment of autochthonous plant species is an essential strategy for recovering degraded areas under semiarid conditions. A field experiment was carried out to assess the short-term effect of two reafforestation methods involving mycorrhizal inoculation and compost addition on soil quality parameters and Rhamnus lycioides seedling growth. The nutrient content (NPK) and enzymatic activities (dehydrogenase, urease, protease-BAA, acid phosphatase and β-glucosidase) increased and bulk density decreased in the rhizosphere soil with the organic amendment. Biomass C of rhizosphere soil increased by at least 240% with respect to the control soil after mycorrhizal inoculation and the combination of compost addition + mycorrhizal inoculation. Both mycorrhizal inoculation and composted organic residue addition increased R. lycioides seedling growth in the same proportion. In the short term, we conclude that the application of both reafforestation methods not only enhances the establishment of R. lycioides seedlings, but also improves soil quality.  相似文献   
142.
By using observational data and MM5, an observational analysisand numerical study was conducted on the synoptic condition of a severe dust storm that was caused by a Mongolian cyclone whichoccurred from 6 to 8 April 2001. Results illustrated thatthe cyclogenesis was due to the isentropic potential vorticity (IPV) advection in the upper troposphere and the terrain modifiedbaroclinicity in the mid-lower troposphere. The Altai-Sayan complex of mountains blocked the lower level cold air and made the isentropic surface sharply steep. When the air slid down along the isentropic surface the increasing of baroclinicity anddecreasing of stability blew up the vertical vorticity development.The formation of the dust storm was a result of a cyclonic cold front passing across the area. The occurrence of this dust stormwas closely related to the strong surface wind, which was accompanied by a cold front passing, rather than the cyclogenesis, itself. Hence, the reason for the pre-front dust storm formulation was the formation of heating convection. Reasons behind the formation of a black storm (visibilitylower than 50 m), which occurred in the mid-north part ofInner Mongolia, lay in several aspects. Firstly, in thisarea the surface wind was strong, a direct result of thedownward transport in mid-lower troposphere. Secondly,the cold front passed over the effected area near sunsetso the air obtained much more surface heating to form adeeper mixed layer (ML). Thirdly, cooperation between thelower level wind and the terrain made the atmosphere inthis area and acquired the maximum advective contributionnecessary to form a deep post-front ML. The sensitivityexperiment revealed that surface heat flux was important to the frontal lifting. In addition, the forcing of surface heating wasalso seen as the primary forcing mechanism of frontogenesis. Meanwhile, removal of the surface heat flux made the atmosphericstratification became stable and the pre-storm ML very shallow,which weakened the strength of the dust storm.  相似文献   
143.
再燃法烟气脱硝技术   总被引:4,自引:0,他引:4  
综述了再燃法烟气脱硝技术及其主要影响因素。通过对几种脱硝技术的分析比较,认为再燃脱硝是一种很有前景的脱硝技术,其投资和运行费用界于低NO。燃烧器和选择性催化还原技术之间,有喷氨条件下的先进再燃脱硝效率接近于选择性催化还原技术。总结了国内外对先进再燃脱硝技术各种参数影响条件的研究结果,并论述了该技术的应用要点。  相似文献   
144.
The performance of a wetland system in treating lead (Pb)/zinc (Zn) mine drainage was evaluated by using the polyurethane foam unit (PFU) microbial community (method), which has been adopted by China as a standardized procedure for monitoring water quality. The wetland system consisted of four cells with three dominant plants: Typha latifolia, Phragmites australis and Paspalum distichum. Physicochemical characteristics [pH, EC, content of total suspended solid (TSS) and metals (Pb, Zn, Cd, and Cu)] and PFU microbial community in water samples had been investigated from seven sampling sites. The results indicated that the concentrations of Pb, Zn, Cd, Cu, and TSS in the mine drainage were gradually reduced from the inlet to the outlet of the wetland system and 99%, 98%, 75%, 83%, and 68% of these metals and TSS respectively, had been reduced in concentration after the drainage passed through the wetland system. A total of 105 protozoan species were identified, the number of protozoa species and the diversity index (DI) gradually increased, while the heterotrophic index (HI) gradually decreased from the inlet to the outlet of the wetland system. The results indicated that DI, HI, and total number species of protozoa could be used as biological indicators indicating the improvement of water quality.  相似文献   
145.
The status of combined heavy metal and organo-chlorine pesticide (OCPs; i.e. HCH and DDT) pollution was investigated and the soil environmental quality of the Taihu Lake watershed, one of the most developed regions in China, was evaluated using a fuzzy comprehensive assessment. Statistical analyses showed the presence of combined pollution in the soil. At many sampling sites, heavy metal concentrations were above corresponding background values, indicating the effects of extraneous pollutants. It has been over 20 years since China banned the use of OCPs, but they can still be found in soil samples of this region. HCH levels at all investigated sites were below the Chinese Environmental Quality Standard for Soils. Fuzzy comprehensive assessment showed that the overall soil quality in this region could be categorized as class I. Nevertheless, the high coefficients of variation for levels of DDT, Cd and Hg indicated the existence of some point-source pollution. Continuous monitoring and further studies of the region are recommended to prevent pollution of farmland from these sources.  相似文献   
146.
Mosses are useful, ubiquitous accumulation biomonitors and as such can be used for biomonitoring surveys. However, the biomonitoring of atmospheric pollution can be compromised in urban contexts if the targeted biomonitors are regularly disturbed, irregularly distributed, or are difficult to access. Here, we test the hypothesis that cemeteries are appropriate moss sampling sites for the evaluation of air pollution in urban areas. We sampled mosses growing on gravestones in 21 urban and peri-urban cemeteries in the Paris metropolitan area. We focused on Grimmia pulvinata (Hedwig) Smith, a species abundantly found in all studied cemeteries and very common in Europe. The concentration of Al, As, Br, Ca, Ce, Cl, Cr, Cu, Fe, K, Mn, Ni, V, P, Pb, Rb, S, Sr, Ti, and Zn was determined by a total reflection X-ray fluorescence technique coupled with a slurry sampling method (slurry-TXRF). This method avoids a digestion step, reduces the risk of sample contamination, and works even at low sample quantities. Elemental markers of road traffic indicated that the highest polluted cemeteries were located near the highly frequented Parisian ring road and under the influence of prevailing winds. The sites with the lowest pollution were found not only in the peri-urban cemeteries, adjoining forest or farming landscapes, but also in the large and relatively wooded cemeteries located in the center of Paris. Our results suggest that (1) slurry-TXRF might be successfully used with moss material, (2) G. pulvinata might be a good biomonitor of trace metals air pollution in urban context, and (3) cemetery moss sampling could be a useful complement for monitoring urban areas.
Graphical abstract We tested the hypothesis that cemeteries are appropriate moss sampling sites for the evaluation of air pollution in urban areas. We sampled 110 moss cushions (Grimmia pulvinata) growing on gravestones in 21 urban and peri-urban cemeteries in the Paris metropolitan area. The concentration of 20 elements in mosses was determined by a total reflection X-ray fluorescence technique coupled with a slurry sampling method. Statistical analysis revealed that: - Urbanized Parisian areas crossed by traffic roads have the highest polluted cemeteries with a strong influence of main wind direction on the distribution of air pollutants - As expected, small cemeteries with low tree density were heavily polluted - Less obvious, large green spaces such as large cemeteries (Père Lachaise, Montmartre, Montparnasse) in the center of a dense metropolis like Paris present the same level of atmospheric trace metal pollution as cemeteries in less urbanized areas or nearing a very large forest. This suggests that even in densely urbanized areas, there is more spatial variability in pollution distribution than usually assumed and that large urban areas with low traffic and green filters such as trees are likely to intercept air pollutants
  相似文献   
147.
Corridors (variably called landscape linkages, connectors, and gateways) are expanses of a landscape that facilitate the flow or movement of individuals, genes, and ecological processes. Protected areas with their buffer zones and the corridors that connect them are cornerstones of modern conservation actions to maintain the biodiversity we have and restore what we have lost. Policy and governance to guide the establishment and management of protected areas and supporting buffer zones is well established in the Central Indian Highlands. A policy and governance structure to create the context and enabling conditions for corridor maintenance, creation, and recovery is emerging but is constrained by the reigning land-management paradigm that separates conservation from development rather than mainstreaming species and habitat conservation into the rural development agenda. Well-nourished, healthy human populations and healthy ecosystems are inextricably linked. The worsening ecological conditions in the Central Indian Highlands can trigger the emergence of a common agenda for an inclusive, caring, and environment-friendly mode of development. The alternative is the business-as-usual scenario: a continuation of worsening ecological conditions. Entry points through the biodiversity, agriculture production, resource extraction, and economic/social sectors to enable integrated sustainable landscape management are identified. These include deepening what it means to successfully conserve a species combined with explicit threat analysis for at-risk tigers and the landscapes that supports them; landscape scenario modeling to advance communication by synthesizing diverse forms of research and articulating and evaluating alternative socio-economic futures; and the use of the smart green infrastructure process as an approach to development rather than only as a way to mitigate environmental damage. Models are presented to scale up from isolated conservation interventions to collective impact that unites supportive government partners with individuals, NGOs, and economic interests to achieve viable long-term relationships in human and natural systems to value, maintain, and recover landscape connectivity.  相似文献   
148.
PACE2016中国环境治理国际研讨会就中国环境政府治理、环境市场治理、环境社会治理以及环境治理结构展开了深入研讨并达成以下共识:大国模式下的环境政府治理面临着突出的"污染避难所效应"、"公平与效率的两难"和"多层次治理体系"等问题;不成熟市场经济条件下环境市场治理必然面临"要不要走环境治理市场化之路"的疑虑,相关研究表明市场手段作为有效的环境治理方式正在逐渐地打消此等疑虑;中国环境治理最主要的短板在于社会治理,提高公众参与度的主要挑战在于改变地方政府的态度,然而社会企业家是环境社会治理的希望;多元环境治理结构是中国环境治理的必然选择,政府引领、企业自觉、公众参与的制衡机制是关键。  相似文献   
149.
Capps and Lederman, in a paper published in this journal in 2015, argued that, at the time, the dismal circumstances of the Ebola outbreak in West Africa was an opportunity to revisit public health responses to emergent infectious diseases. Using a One Health lens, they argued for an ecological perspective—one that looked to respond to zoonoses as an environmental as well as public health concern. Using Ebola virus disease as an example, they suggested shared immunity as a strategy to vaccinate both humans and great apes. Since then, vaccination as a conservation strategy in this case has been debated and at least one great ape vaccination trial has been proposed: some, however, are less convinced of the ethical arguments to pursue vaccinating wild animals. Using this opportunity, we review Capps and Lederman’s arguments and directly respond to the plausible objections to them.  相似文献   
150.
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