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61.
Effects of Recreational Impacts on Soil Microbial Communities 总被引:51,自引:0,他引:51
/ The functional diversity of soil microbial communities in heavilyimpacted subalpine campsites and adjacent undisturbed areas was comparedusing the Biolog method of carbon utilization profiles. Principal componentsanalysis of patterns and level of microbial activity indicate that microbialcommunities differentiate in response to disturbance in the top 6 cm of soil,while below 6 cm there were no recognizable differences between disturbed andundisturbed soil communities. Analysis of the factors that differentiate theupper microbial communities between disturbed and undisturbed sites revealedthat the percent of total carbon sources utilized was significantly less inthe disturbed (54%) than in undisturbed areas (95%). Carbonsubstrates important in the discrimination between soil communities includeplant, invertebrate, and microbial derivatives that could not be metabolizedby microbial communities from disturbed sites. Comparisons of totalculturable actinomycetes, bacteria, and fungi reveal no difference in overallnumber of colony forming units (CFU) on disturbed and undisturbed sites, buta marked decrease in actinomycetes on disturbed sites. Biolog andspread-plate data combined indicate a shift in the structure and function ofthe microbial community in campsite soils, which may be a useful indicator ofsoil community disturbance.KEY WORDS: Microbial functional diversity; Anthropogenic disturbance;Recreational impacts; Carbon source profile; Subalpine 相似文献
62.
中国的污水处理与水环境管理政策 总被引:1,自引:0,他引:1
孙锡凯 《中国环境管理干部学院学报》2003,13(2):5-7
中国已建有420座污水处理厂,城市污水处理率达30%以上。但污水处理任务仍很艰巨,必须采取加强工业污染防治,建设大批新的污水处理厂和控制面源污染等对策。 相似文献
63.
青岛市大气颗粒物中多氯联苯的污染特征研究 总被引:3,自引:1,他引:2
采集2005年1月至12月的大气颗粒物样品,对青岛大气颗粒物中多氯联苯(PCBs)的浓度、组成和时间变化特征进行了研究,结果表明,大气颗粒物中∑7PCBs的含量范围为5.22—8.58pg/m3,月平均值为7.32pg/m3,浓度季节变化不明显。只有PCB28和PCB52两种单体的浓度随温度或气候的变化相对变化较明显,并且大气颗粒物中的PCBs表现出明显的三氯、四氯优势,随着取代氯原子数从3升高至7,同族体比例呈现逐渐降低的趋势。结合PCBs的污染特征进行分析,推断其污染来源除了大气的远距离运移外,主要是存在于本研究区域。 相似文献
64.
Atmosphericmixing ratios of carbonyl sulfide (COS) in Beijingwere intensivelymeasured from March 2011 to June 2013. COS mixing ratios exhibited distinct seasonal variation, with a maximumaverage value of 849 ± 477 pptv in winter and a minimal value of 372 ± 115 pptv in summer. The seasonal variation of COS was mainly ascribed to the combined effects of vegetation uptake and anthropogenic emissions. Two types of significant linear correlations (R2 > 0.66) were found between COS and CO during the periods from May to June and from October to March, with slopes (ΔCOS/ΔCO) of 0.72 and 0.14 pptv/ppbv, respectively. Based on the emission ratios of COS/CO from various sources, the dominant anthropogenic sources of COS in Beijing were found to be vehicle tire wear in summer and coal burning in winter. The total anthropogenic emission of COS in Beijing was roughly estimated as 0.53 ± 0.02 Gg/year based on the local CO emission inventory and the ΔCOS/ΔCO ratios. 相似文献
65.
通过计算邕江上游的水环境容量,对邕江水环境容量的价值做进一步的讨论,确保水源地的安全。分析了邕江水源地上游河段的水文特征,以具有代表性的COD和NH3-N为控制因子,选用水环境容量二维模型,按照水情保证率95%进行计算。得出2007年COD和NH3-N的已利用容量为2751.37t/a和117.63t/a。在对邕江水质进行评价的基础上,还预测出邕江水源地上游河段的COD和NH3-N剩余水环境容量呈上升趋势,这表明水源地上游水质安全。 相似文献
66.
67.
Subba Rao N 《Environmental monitoring and assessment》2008,136(1-3):437-447
Trace elements are essential for human health. However, excess concentrations of these elements cause health disorders. A
study has been carried out in Visakhapatnam environs, Andhra Pradesh, India to ascertain the causes for the origin and distribution
of iron content in the groundwaters. Fifty groundwater samples are collected and analyzed for iron. The content of iron ranges
from 400 to 780 μg/l. A comparison of groundwater data with rock and soil chemistry suggests that the concentration of iron
(400–530 μg/l) in the groundwaters is derived from the rocks and soils due to geogenic processes. This concentration is taken
as a natural occurrence of iron in the groundwaters of the study area for assessing the causes for its next higher content
(>530 μg/l). Relatively higher concentration of iron (540–550 μg/l) is observed at some well waters, where the wells are located
nearby municipal wastewaters, while the very high concentration of iron (610–780 μg/l) is observed in the industrially polluted
groundwater zones, indicating the impact of anthropogenic activities on the groundwater system. These activities mask the
concentration of iron caused by geogenic origin. Hence, both the geogenic and anthropogenic activities degrade the groundwater
quality. Drinking water standards indicate that the iron content in all the groundwater samples exceeds the permissible limit
(300 μg/l) recommended for drinking purpose, causing the health disorders. Necessity of close monitoring of groundwater quality
for assessing the impact of geogenic and anthropogenic sources with reference to land use/land cover activities is emphasized
in the present study area to protect the groundwater resources from the pollution. 相似文献
68.
能源规划环境影响评价内容框架实践与探讨 总被引:3,自引:0,他引:3
规划环评是环评领域一个新方向。虽然环评法已经实施,但目前在实际执行过程中,对编制的规划如何按照规划环评导则组织规划环评以及对规划环评思路和内容框架尚没有具体的研究。本文从实践出发并结合环境与发展综合决策的角度,以浙江省2010年电力发展规划及2020年展望的能源类规划环评为案例,对能源类规划环评的内容框架作初步研究。 相似文献
69.
The impact of climate changes on the pollution levels in Denmark is the major topic of this paper. Variations of the Danish air pollution levels that are caused by climatic changes are studied together with variations caused by other factors (emissions, inter-annual variability of meteorological conditions, etc.). The Unified Danish Eulerian Model (UNI-DEM) was run on a fine, 10 km × 10 km, grid over a space domain covering all of Europe to minimize the influence of the boundary conditions on the Danish pollution levels. This study is based on four categories of scenarios: (i) traditional scenarios, (ii) climatic scenarios, (iii) scenarios with variations of the human-made (anthropogenic) emissions and (iv) scenarios in which the biogenic emissions were varied. The total number of applied scenarios was 14, and a time-period of 16 years was used. The results show clearly that although the concentrations of the major pollutants do not depend too much on the climatic changes, some quantities, in particular quantities related to high ozone levels, might be increased significantly as a result of the warming trends in the future climate. The reason for this phenomenon is explained. 相似文献
70.
Zhao Y Duan L Lei Y Xing J Nielsen CP Hao J 《Environmental pollution (Barking, Essex : 1987)》2011,159(10):2726-2732
China’s strategies to control acidifying pollutants and particulate matter (PM) may be in conflict for soil acidification abatement. Acidifying pollutant emissions are estimated for 2005 and 2020 with anticipated control policies. PM emissions including base cations (BCs) are evaluated with two scenarios, a base case applying existing policy to 2020, and a control case including anticipated tightened measures. Depositions of sulfur (S), nitrogen (N) and BCs are simulated and their acidification risks are evaluated with critical load (CL). In 2005, the area exceeding CL covered 15.6% of mainland China, with total exceedance of 2.2 Mt S. These values decrease in the base scenario 2020, implying partial recovery from acidification. Under more realistic PM control, the respective estimates are 17.9% and 2.4 Mt S, indicating increased acidification risks due to abatement of acid-neutralizing BCs. China’s anthropogenic PM abatement will have potentially stronger chemical implications for acidification than developed countries. 相似文献