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591.
湿地构成变化与湿地保护 总被引:1,自引:0,他引:1
湿地不合理的开发利用 ,对湿地构成诸如水文、土壤、水质、植被和动物都造成了不同程度的负面影响 ,这些影响相互作用 ,使得湿地生态系统极为脆弱 ;通过对它们的分析 ,提出了相应的湿地保护措施 相似文献
592.
淮安湿地现状调查和可持续发展 总被引:2,自引:0,他引:2
从2004-2006年上半年以来,对淮安市的湿地现状进行了调查,并对其功能、效益进行了分析,指出了淮安市湿地保护存在的问题,同时强调必须要运用宣传教育、科学规划、统筹兼顾、协调管理、加大投入等手段来保护生物多样性,实现环境、经济、社会效益的可持续发展。 相似文献
593.
生物-生态优化组合工艺试验规模为100 m3/d,通过探索自然启动阶段生物-生态的优化组合模式,提高了启动中组合工艺的处理效能、缩短了处理效能波动时段,实现了向运行阶段的平稳过渡,为工程规模的启动提供了系统依据.研究表明,在启动阶段通过生物-生态优化工况组合,可达到组合工艺COD去除率90%、TN去除率40%~70%、TP去除率90%的去除效果. 相似文献
594.
Amphibian Breeding Distribution in an Urbanized Landscape 总被引:5,自引:0,他引:5
Abstract: Amphibians commonly use wetlands for breeding habitat, and given the concern about their ongoing global declines, the effects of urbanization on the breeding distribution of amphibians need to be quantified. Thus, we conducted a survey of the larval amphibian community in central Pennsylvania (U.S.A.) wetlands along an urbanization gradient. Wetlands in urban areas had less surrounding forest and wetlands and greater road density than rural wetlands. Urbanization was also associated with increases in hydroperiod (i.e., wetland permanency) and the presence of fish predators. Moreover, urban wetlands had lower larval amphibian species richness than rural wetlands. This decrease in richness was attributable to a decrease in occurrence of wood frogs ( Rana sylvatica ) and ambystomatid salamanders ( Ambystoma maculatum and A. jeffersonianum ) in urban sites. Wood frogs and ambystomatid salamanders were positively associated with the amount of forest surrounding sites and negatively associated with hydroperiod. As a result, we hypothesize that these species are sensitive to the effects of urban development. The remaining species in this study appear fairly resilient to the effects of urbanization. These data demonstrate the importance of quantifying both local and landscape attributes when describing the factors that limit the breeding distribution of amphibians. We recommend that to preserve amphibian biodiversity in urbanized landscapes, it is best to focus on regional diversity, which protects a variety of sites that encompass various hydroperiods, have adequate buffer habitat, and are connected by dispersal routes. 相似文献
595.
Mirady Sebastiani Sara Elena González María Mercedes Castillo Pablo Alvizu María Albertina Oliveira Jorge Pérez Antonio Quilici Martín Rada María Carolina Yáber Miguel Lentino 《Environmental management》1994,18(5):647-661
In Venezuela, large-scale shrimp farming began in the 1980s. By 1987, the Ministry of Environment and Natural Resources (MARNR)
had received 14 proposals for approval. A developer illegally started the construction of ponds at the Píritu Lagoon in the
State of Anzoátegui before the authorization process was completed. This action triggered a land-use conflict. This study
identifies the causes for public protest and determines the consequences of this conflict for land-use management. The results
show that public protest was based on the impacts of the partial construction of ponds. These impacts were related to direct
removal of wetlands, interruption of natural patterns of surface flows, and alteration of feeding grounds of some bird species
with migratory status. Consequences were identified in relation to the role that nongovernmental organizations (NGOs) play
in land-use conflicts and the actions that MARNR could take in the future to prevent and solve similar situations. 相似文献
596.
为了解植物种类对表面流人工湿地的净化效果的影响及其与微生物群落的关系,研究了4种植物条件下表面流人工湿地的氮磷平衡以及微生物群落结构。结果表明,各组人工湿地对氨氮(45.53%~80.95%)、总氮(53.67%~80.30%)和总磷(32.97%~55.77%)都有较好的处理效果,种植植物的人工湿地比未种植的人工湿地具有更高的氨氮、总氮和总磷去除效果,其中黄菖蒲组对氮的去除效果最好,美人蕉组对磷的去除效果最好。在表面流人工湿地中,微生物作用(34.84%~45.44%)是人工湿地氮去除的主要途径,基质吸附(20.90%~23.91%)是人工湿地磷去除的主要途径,但是种植植物的人工湿地的氮磷通过微生物去除的量更高。高通量测序分析表明,相较于未种植植物的人工湿地,种植植物的人工湿地显示出更高的微生物丰富度、多样性和更高的脱氮除磷功能微生物的丰度。假单胞菌属、不动杆菌属、芽孢杆菌属和硝化螺菌属是人工湿地中主要的脱氮菌属,也是种植植物的人工湿地高生物脱氮的原因。假单胞菌属和不动杆菌属丰度增加是种植植物的人工湿地高生物除磷的原因。 相似文献
597.
598.
围垦对海滨地区景观演变及其质心移动的影响——以盐城保护区部分区域为例 总被引:1,自引:0,他引:1
将盐城国家级自然保护区(新洋港-四卯酉河段)划分为未围区和围垦区,根据1984-2013 年6 个时相的景观资料,运用RS、GIS 技术和景观生态学方法,分析围垦活动影响下海滨湿地景观格局演变差异。结果如下:①未围区始终保持以自然景观为主,2013 年面积比例占84.6%;1984-2013 年,芦苇和互花米草湿地面积分别增长了4 770.6 和4 202.8 hm2,而碱蓬湿地面积减少了2 656.7 hm2。围垦区大致以2000 年为界,景观结构由自然景观占主导转为人工景观为主;除互花米草外自然植被面积呈下降趋势,而人工景观中水产养殖塘面积不断上升,2013 年比例达60.5%。②未围区景观破碎度自1995 年以后变幅较小,且保持在较低水平,维持在0.27~0.28,斑块形状趋于复杂、自然,景观多样性呈上升趋势,1984-2013 年上升了0.19。围垦区破碎化程度上升明显,1984-2013 年上升了0.27,整体景观趋于简单规则,景观多样性呈下降趋势,1984-2013 年下降了0.26。③未围区景观演变驱动力以自然因素为主,景观类型质心移动具有距离较为连续、方向相对单一的特征。而围垦区由于人类活动介入,围垦区景观类型质心移动更多地表现出无序多变、错综复杂的特征。 相似文献
599.
Christopher J. Woltemade Jinnieth Woodward 《Journal of the American Water Resources Association》2008,44(1):222-234
ABSTRACT: In 2001, the 1.04‐ha Hornbaker wetland in south‐central Pennsylvania was restored by blocking an artificial drainage ditch to increase water storage and hydraulic retention time (HRT). A primary goal was to diminish downstream delivery of nitrate that enters the wetland from a limestone spring, its main source of inflow. Wetland inflow and outflow were monitored weekly for two years to assess nitrate flux, water temperature, pH, and specific conductivity. In Year 2, spring discharge was measured weekly to allow calculation of nitrate loads and hydraulic retention time. Surface runoff was confirmed to be a small fraction of wetland inflows via rainfall‐runoff modeling with TR‐55. The full dataset (n = 102) was screened to remove 13 weeks in which spring discharge constituted < 85% of total inflows because of high precipitation and surface runoff. Over two years (n = 89), mean nitrate‐nitrogen concentrations were 7.89 mg/l in inflow and 3.68 mg/l in outflow, with a mean nitrate removal of 4.19 mg/l. During Year 2 (n = 47), for which nitrate load data were available, the wetland removed an average of 2.32 kg N/day, 65% of the load. Nitrate removal was significantly correlated with HRT, water temperature, and the concentration of nitrate in inflow and was significantly greater during the growing season (5.36 mg/l, 64%) than during the non‐growing season (3.23 mg/l, 43%). This study indicates that hydrologic restoration of formerly drained wetlands can provide substantial water quality benefits and that the hydrologic characteristics of spring‐fed wetlands, in particular, support effective nitrogen removal. 相似文献
600.
ZnCo-LDHs改性人工湿地沸石基质对城市污水的净化效果 总被引:1,自引:0,他引:1
选取常用的垂直流人工湿地沸石基质,采用金属离子物质的量比(Zn~(2+)∶Co~(3+))为2∶1在碱性环境下共沉淀生成ZnCo-LDHs,并覆膜于沸石基质表面,分析了改性前后基质的物化特性;构建模拟垂直流人工湿地基质试验柱,对改性前后2种沸石基质对城市污水的净化效果进行了研究。结果表明:Zn Co-LDHs覆膜改性沸石基质的方法是可行的;ZnCo-LDHs覆膜于基质表面,改变了原始沸石基质的物理化学特性,促进了基质对污染物的物理拦截和物化吸附作用;ZnCo-LDHs改性基质对城市污水中CODCr、氨氮、TP的净化效果均有所提高,其平均去除率分别达到了76%、63%和88%。 相似文献