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大庆油田湖泊湿地景观生态设计探讨 总被引:3,自引:1,他引:3
采用景观生态设计的方法,将大庆油田职工生活居住区内湖泊湿地的湖盆、湖岸、湿地、水体及植物、地貌、土壤等自然因素作为一个整体,对湖底、湖岸、浅水区、湖滨带等地进行了景观生态设计。该设计方案体现了地方性特征,保护与节约了自然资源,显露了自然特色,达到了对环境影响最小、资本投入少、生态效益最大的设计目的。 相似文献
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近几十年,我国经济建设高速迅猛发展,楼房高了、汽车多了、道路宽了、口袋鼓了,但同时,我们的生存环境也差了。如今,厚厚的灰霾像一个硕大无边的盖子整天罩在我们许多城市的上空,即使那些戴着"环保模范城市"、"生态示范区"、"生态市"、"宜居城市"桂冠的城市也是如此。我们的城市病了,钢筋水泥森林间流动的是污浊的空气。如果 相似文献
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如今,已经很难想象,当人们第一次开始运用化肥、农药、催熟剂、催红剂、膨大剂……等各类化学药剂时,曾经有过怎样的喜悦心情。这些化学药剂增加了产量、减少了病虫害、提高了农民收益、节约了人工投入、改善了各类农产品的商品卖相、降低了农业生产所存在的很多不确定风险。所以,"化学农业"替代了"传统农业",恐怕是一个必然的结果。尽管,"化学农业"给自然环境和人类健康带来了巨大的风险和危机。然而,人类社会的发展是一个永不停歇的过程,任何必然的结果都不可能因为其必然性而不被否决。事实上,只要当事物的结果不符合发展的内涵时,都必须予以反思,并寻找新的出路。 相似文献
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党的十八大报告深刻体现了承前启后、继往开来、务实创新的精神,特别是突出了"12459"的量化任务和目标,进一步规划了我国科学发展、创新驱动、转型发展、可持续发展的蓝图,鼓舞人心、激励奋进,我们必须深入学习与领会。 相似文献
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系统搜集了汉中、安康、商洛2002—2008年旅游收入、旅游客流量和GDP数据,利用"速度、质量、效益"模型,基于经济贡献率、增长弹性、拉动系数、产业结构和旅游就业5个指标,对陕南汉江走廊旅游开发带动区域发展进行了实证研究。结果显示,陕南3市旅游发展刺激陕南需求、拉动陕南内需,带动了相关产业的发展;3市旅游发展优化了陕南产业结构,促进了城市化进程,增加就业机会、促进了社会公平;3市旅游发展带动了陕南的经济增长;3市旅游发展对区域经济发展的带动程度各有不同,体现在不同层面,揭示了旅游发展带动区域经济的动态过程。 相似文献
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现阶段,我国居民经济能力提高,出现了浪费型消费与攀比型消费,加上日益增长的人口数量,形成了一个巨大的"吞噬环境圈"。为了研究消费对环境的影响,本文立足于消费对碳排放量的影响,构建了STIRPAT模型,分析了人口数、城市化率、人均消费量、碳排放强度对碳排放总量的影响;得出了城市化率对碳排放量具有明显增加作用的结论;计算了人口数、城市化率、人均消费量的增长对碳排放增长量的贡献率,得出了人口数和人均消费量的变化对碳排放量的变化也有显著影响的结论;描述了我国五类消费品的增长情况;提出了消费方式从个人到企业,再到政府,最后到世界的转变过程与转变消费方式的路径,包括建立绿色GDP核算体系、进行绿色城市化、继续降低碳排放强度、加强教育和宣传以改变现存消费观、利用行政和法律实现节能低碳消费方式、重视新型能源技术的开发、拓展利用资源的广度和深度、加强国际交流与合作;最后,总结了改变物质主义价值取向和行为规范,完善绿色产品及基础设施的供给需要注意的三个方面。 相似文献
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古村落旅游地游客市场发展动力学研究——以西递、宏村为例 总被引:3,自引:0,他引:3
运用系统动力学构建了西递、宏村旅游地发展的系统动态模型,分析了西递、宏村游客市场结构,同时分析了模型建立下的西递、宏村近程观光市场和远程观光市场的发展机制反馈,并针对西递、宏村古村落目前旅游发展中存在的问题提出了调控对策和建议。 相似文献
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NEBS认证,是电信网络设备进入北美地区电信网络的通行证。本文把获取NEBS认证的全过程划分为三个阶段,即准备阶段、设计阶段和实施阶段,并论述了各阶段的关键要点。首先,在准备阶段对NEBS进行了介绍,简要分析了NEBS认证的主要标准,同时指出运营商的特殊要求的重要性。接着分析了在设计阶段应该注意的技术点,如空间尺寸要求、电源输入、接地、防火、地震等。最后,讨论了认证测试阶段面临的困难,并强调了认证前摸底测试的重要性及必须具备足够的耐心。 相似文献
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Reclaimed Appalachian surface mined lands have difficulty in sustaining native deciduous forest communities. Establishing prairie communities could increase ecosystem function; however, a native model system does not exist. We evaluated establishment of 15 North American prairie grasses as monocultures on reclaimed mine soil in southeast Ohio in four randomized complete blocks planted May 2005 and 2006. Population density was assessed 30 d after planting (30 DAP) and in October of the planting year (YR1) and second year following planting (YR2) and expressed as percentage of viable seeds sown (PVSS). Canopy cover of nonnative species reestablishing in the plots was measured in 2007. Eastern gamagrass ( L.) population was >50 PVSS in all censuses. Western wheatgrass [ (Rydb.) A. L?ve] was initially 7 PVSS at 30 DAP, but increased to 154 PVSS by YR2 from rhizomes spreading into gaps. Big bluestem ( Vitman) was 7 PVSS at 30 DAP and 4 PVSS at YR2. Blue grama [ (Willd. ex Kunth) Lag. ex Griffiths] and sideoats grama [ (Michx.) Torr.] did not survive past YR1. Gaps left from poor stand establishment were primarily recolonized by nonnative Kentucky bluegrass ( L.) in the 2005 planting and birdsfoot trefoil ( L.) in the 2006 planting, but was least in eastern gamagrass and tall dropseed [ (P. Beauv.) Kunth]. This research demonstrates the potential for increasing diversity and species richness on mine soil habitats with regionally native grasses that could increase functional quality through ecological resilience. 相似文献
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Tan K Anderson TA Jones MW Smith PN Jackson WA 《Journal of environmental quality》2004,33(5):1638-1646
Previous laboratory-scale studies have documented perchlorate ClO(-)(4) uptake by different plant species, but less information is available at field scale, where ClO(-)(4) uptake may be affected by environmental conditions, such as distance to streams or shallow water tables, exposure duration, and species. This study examined uptake of ClO(-)(4) in smartweed (Polygonum spp.) and watercress (Nasturtium spp.) as well as more than forty trees, including ash (Fraxinus greggii A. Gray), chinaberry (Melia azedarach L.), elm (Ulmus parvifolia Jacq.), willow (Salix nigra Marshall), mulberry [Broussonetia papyrifera (L.) Vent.], and hackberry (Celtis laevigata Willd.) from multiple streams surrounding a perchlorate-contaminated site. Results indicate a large potential for ClO(-)(4) accumulation in aquatic and terrestrial plants, with ClO(-)(4) concentration in plant tissues approximately 100 times higher than that in bulk water. Perchlorate accumulation in leaves of terrestrial plants was also dependent on species, with hackberry, willow, and elm having a strong potential to accumulate ClO(-)(4). Generally, trees located closer to the stream had a higher ClO(-)(4) accumulation than trees located farther away from the stream. Seasonal leaf sampling of terrestrial plants indicated that ClO(-)(4) accumulation also was affected by exposure duration, with highest accumulation observed in the late growing cycle, although leaf concentrations for a given tree were highly variable. Perchlorate may be re-released into the environment via leaching and rainfall as indicated by lower perchlorate concentrations in collected leaf litter. Information obtained from this study will be helpful to understand the fate of ClO(-)(4) in macrophytes and natural systems. 相似文献
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Transpiration and Root Development of Urban Trees in Structural Soil Stormwater Reservoirs 总被引:2,自引:0,他引:2
Julia Bartens Susan D. Day J. Roger Harris Theresa M. Wynn Joseph E. Dove 《Environmental management》2009,44(4):646-657
Stormwater management that relies on ecosystem processes, such as tree canopy interception and rhizosphere biology, can be
difficult to achieve in built environments because urban land is costly and urban soil inhospitable to vegetation. Yet such
systems offer a potentially valuable tool for achieving both sustainable urban forests and stormwater management. We evaluated
tree water uptake and root distribution in a novel stormwater mitigation facility that integrates trees directly into detention
reservoirs under pavement. The system relies on structural soils: highly porous engineered mixes designed to support tree
root growth and pavement. To evaluate tree performance under the peculiar conditions of such a stormwater detention reservoir (i.e., periodically
inundated), we grew green ash (Fraxinus pennsylvanica Marsh.) and swamp white oak (Quercus bicolor Willd.) in either CUSoil or a Carolina Stalite-based mix subjected to three simulated below-system infiltration rates for
two growing seasons. Infiltration rate affected both transpiration and rooting depth. In a factorial experiment with ash,
rooting depth always increased with infiltration rate for Stalite, but this relation was less consistent for CUSoil. Slow-drainage
rates reduced transpiration and restricted rooting depth for both species and soils, and trunk growth was restricted for oak,
which grew the most in moderate infiltration. Transpiration rates under slow infiltration were 55% (oak) and 70% (ash) of
the most rapidly transpiring treatment (moderate for oak and rapid for ash). We conclude this system is feasible and provides
another tool to address runoff that integrates the function of urban green spaces with other urban needs. 相似文献
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The effect of land use on soil health indicators in peri-urban agriculture in the humid forest zone of southern cameroon 总被引:1,自引:0,他引:1
The objective of this study was to identify the effect of different land uses in peri-urban agriculture on the soil properties. Soil health indicators were evaluated in the top 10 cm at five tilled agricultural sites involving different cropping systems and use of agrochemicals within the peri-urban agricultural areas of Yaounde, Cameroon, and compared with a native forest land. The experimental data showed that the selected indicators were sensitive to cropping practice. Most cropped land had significantly higher total C, available N and P concentrations, soil pH, electrical conductivity, salinity, biomass C and P, dehydrogenase, beta-glucosidase, and acid phosphatase activities. Land producing corn (Zea mays L.) and sugarcane (Saccharum officinarum L.) differed from that producing tomatoes (Lycopersicon esculentum Mill.), but cultivation of these crops has significantly impacted native soil quality. However, phenol oxidase, microbal biomass C/organic C (C(mic)/C(org)), and microbial biomass C/microbial biomass P (C(mic)/P(mic)) were negatively affected. These appeared to be more consistent indicators of negative management causing changes to soil health and may be suitable for an early appraisal of soil health. 相似文献
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The concentrations of copper (Cu) and lead (Pb) in, and the biomass of, the different parts of Persicaria glabra (Willd.) Gamez and Juncellus alopecuroides (Rottb.) C.B.Cl. were evaluated while grown in pots under laboratory conditions. Cu and Pb were added as sulphates (50, 100,
200, 400 mg/kg) to the pots. Heavy metal concentrations in the plants were measured by atomic absorption spectrometry. Results
reveal that the biomass of J. alopecuroides (particularly roots) was higher than P. glabra, and that the growth tendency of macrophytes decreased with increasing heavy metal concentration in the soil, while in P. glabra, biomass went on increasing with the increase in copper concentration. Heavy metal accumulation in the roots was more than
in aerial parts, and, therefore, barring two exceptions, the transfer factor of heavy metals from roots to aerial parts showed
as less than 1, suggesting less transfer of heavy metals from roots to aerial parts. Thus, these macrophytes are efficient
accumulators of trace elements, particularly J. alopecuroides, which can be recommended for biofiltration of heavy metals from contaminated soils. 相似文献
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Lead poisoning of waterfowl from direct ingestion of wetland mine tailings has been reported at the Coeur d'Alene River basin in Idaho. A greenhouse study was conducted to evaluate the effects of surface applications of amendments on lead bioavailability in the tailings. Treatments included sediment only, and sediment with three different surface amendments: (i) biosolids compost plus wood ash, (ii) compost + wood ash + a low SO4(2-) addition as K2SO4, and (iii) compost + wood ash + a high SO4(2-) addition. Measured variables included growth and tissue Pb, Zn, and Cd concentration of arrowhead (Sagittaria latifolia Willd.) and cattail (Typha latifolia L.) and soil pH, redox potential (Eh), pore water Pb, Pb speciation by X-ray absorption spectroscopy, and in vitro Pb bioavailability. The compost + ash amendment alleviated phytotoxicity for both plant species. Bioavailability of Pb as measured by a rapid in vitro extract decreased by 24 to 34% (over control) in the tailings directly below the amendment layer in the compost + SO4 treatments. The ratio of acid volatile sulfide (AVS) to simultaneously extracted metals (SEM) also indicated a reduction in Pb bioavailability (1:40 control, 1:20 compost, 1:8 compost + low SO4, and 1:3 compost + high SO4). Extended X-ray adsorption fine structure (EXAFS) and X-ray absorption near edge structure (XANES) spectroscopy data indicated that lead sulfide was greater after 99 d in the treatments that included additions of sulfate. These results indicated that, under reducing conditions, surface amendments of compost + wood ash (with or without sulfate) decreased the bioavailability of Pb in metal-contaminated mine tailings. 相似文献
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