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21.
苔藓植物资源丰富、种类繁多、分布广泛,是一类以孢子繁殖,由水生向陆生过渡的高等植物。苔藓植物的结构相对简单,对环境变化的反应较为敏感,被广泛应用为环境污染的指示植物。苔藓植物生长与所处的环境有关,而它的生长对土壤结皮形成、水土保持、生态小环境改善等方面又发挥着重要的促进作用。综述了苔藓植物的资源分布、苔藓植物对环境污染的响应、苔藓植物的生态效应等方面的研究进展,但是目前的研究领域及其研究角度还存在着各自的不足。随着经济建设快速发展,世界各地大量的矿山开采、水电开发等工程建设对土地、自然环境的破坏日益严重,非农业建设以及农产品需求不断增加造成了农田的生态结构与功能发生着不断变化。针对各地经济社会发展以及城乡建设现状,积极开展工程建设领域以及农田生态系统苔藓植物的生态环境效应研究是今后值得十分重视的研究方向。  相似文献   
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城市道路绿化带不同植物叶片附尘对大气污染的磁学响应   总被引:3,自引:1,他引:2  
隆茜  周菊珍  孟颉  达良俊 《环境科学》2012,33(12):4188-4193
对上海市金沙江路两侧绿化带内24个常绿植物叶片样品进行了磁性与重金属测试,以探讨城市道路绿化带不同植物叶片附尘对大气污染的磁学响应.结果表明,χ、SIRM值分别在(4~59)×10-8m3.kg-1和(496~6 114)×10-6Am2.kg-1之间变化,S-300 mT在89%~98%之间变动.所有植物样品中χARM/χ〈4,χARM/SIRM〈30×10-5mA-1.磁性参数表明,植物叶片附尘以亚铁磁性矿物为主,磁性矿物颗粒以假单畴(PSD)-多畴(MD)为主.重金属元素Zn、Cu、Pb含量与反映亚铁磁性矿物含量的χ、SIRM、χARM呈显著正相关,可以将磁性参数SIRM作为叶片重金属元素的替代指标.推荐在上海地区广泛种植的广玉兰作为道路植物污染的指示植物。  相似文献   
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中老年游客是免费公园游客人群的主要群体,以上海市27座免费公园为例,分析中老年两年龄段游客行为特征,以及其对公园设施服务的重要性和满意度。结果表明:中年游客具有择园路程范围广,公共交通利用率高,来园频率低,入园时间晚,喜爱亲子活动,停留时间短等特征;而老年游客则表现出偏爱短距离公园,以步行为主,来园频率高,入园时间早,倾向运动健身,停留时间长等特征。两年龄段游客对公园满意度评价总体相近,均认为绿化、卫生状况和安全性,以及景点、厕所和无障碍设施设置是影响游客来园的关键因子,前3项令游客满意,而后3项却达不到期望。针对两年龄段游客不同的行为和满意度特征,对免费公园的经营管理提出建议。  相似文献   
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Abstract:  We identified 100 scientific questions that, if answered, would have the greatest impact on conservation practice and policy. Representatives from 21 international organizations, regional sections and working groups of the Society for Conservation Biology, and 12 academics, from all continents except Antarctica, compiled 2291 questions of relevance to conservation of biological diversity worldwide. The questions were gathered from 761 individuals through workshops, email requests, and discussions. Voting by email to short-list questions, followed by a 2-day workshop, was used to derive the final list of 100 questions. Most of the final questions were derived through a process of modification and combination as the workshop progressed. The questions are divided into 12 sections: ecosystem functions and services, climate change, technological change, protected areas, ecosystem management and restoration, terrestrial ecosystems, marine ecosystems, freshwater ecosystems, species management, organizational systems and processes, societal context and change, and impacts of conservation interventions. We anticipate that these questions will help identify new directions for researchers and assist funders in directing funds.  相似文献   
27.
对甲烷排放的精准监测是油气行业实现温室气体减排与管控的基础和前提。无人机具有灵活、可操作性强、覆盖范围广、运行成本低等特点,以无人机为飞行平台的甲烷监测技术在油气行业区域甲烷排放监测领域具有巨大的应用潜力。详细阐述了基于无人机平台的甲烷监测技术的优势,梳理了不同的无人机类型,并根据其飞行性能及载荷能力进行了比对,归纳了无人机有效载荷类型、特点及应用场景,总结了国内外无人机甲烷监测技术在油气行业的应用,旨在为基于无人机平台的甲烷监测技术在我国油气行业的应用提供理论和技术参考。  相似文献   
28.
不同雨强对太湖河网区河道入湖营养盐负荷影响   总被引:5,自引:4,他引:1  
陈洁  朱广伟  许海  詹旭  朱梦圆  笪文怡  黄亚文 《环境科学》2019,40(11):4924-4931
为揭示太湖河网区不同雨强下入湖河道面源污染规律,以太湖入湖负荷最大的河道大浦河为例,通过一周年逐日高频监测水体各形态氮、磷及溶解性有机碳等营养盐情况,结合河道流量及降雨量的自动监测资料,分析了大雨、中雨、小雨及无雨等4种降雨强度下太湖河网区典型河道的流量和营养盐负荷特征.结果表明,作为太湖河网区的典型入湖河道,大浦河时常发生往复流现象,观测的365 d内,有60 d日均流量为负值,占16%;河道流量对雨强的响应较为迟缓,仅强降雨事件( 25 mm·d~(-1))下,降雨当日河道流量才显著增加;中雨期平均流量仅比无雨期高了29%,在统计上不显著.河道水体营养盐浓度在不同降雨强度下差异不显著,大雨、中雨、小雨及无雨事件下河道总氮浓度分别为(3. 00±0. 58)、(3. 34±0. 93)、(3. 55±1. 05)和(3. 37±1. 14) mg·L~(-1),小雨事件当天水体总氮浓度均值最高,而4种类型降雨事件下河道总磷含量分别为(0. 228±0. 068)、(0. 258±0. 121)、(0. 219±0. 083)和(0. 225±0. 121) mg·L~(-1),差异性也不显著,就平均值而言,中雨时河道总磷浓度最高.夏季典型降雨过程分析表明,不同雨强发生之后河道溶解性有机碳和各形态氮的浓度变化不大,但大雨之后次日河道各形态磷浓度有明显增高,持续时间为2 d,中雨后次日河道总磷和颗粒态磷有明显增高,持续时间仅为1 d,小雨后磷浓度基本无变化.大雨、中雨、小雨和无雨时总氮日负荷分别为7. 64、3. 19、3. 21和2. 62 t·d~(-1),总磷日负荷分别为0. 59、0. 26、0. 22和0. 20 t·d~(-1),受入湖流量影响,大雨期营养盐日负荷显著高于中雨及以下强度的降雨;然而,由于一年内大雨出现频次较少,大雨期氮和磷总入湖负荷占年负荷的比重不大,大雨期总氮和总磷分别入湖61. 11 t和4. 72 t,占观测周年的5. 6%和5. 8%,这与山区河道降雨负荷间的关系有着显著区别.本高频观测表明,太湖流域平原河网区河道面源污染汇集过程复杂,入湖负荷受降雨强度的影响相对较小,入湖水量是营养盐负荷的重要影响因素.本研究结果对太湖流域平原河网区湖泊的面源污染的估算及控制对策的制定具有参考价值.  相似文献   
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Safeguarding the Pantanal Wetlands: Threats and Conservation Initiatives   总被引:2,自引:0,他引:2  
Abstract:  The Pantanal, one of the largest wetlands on the planet, comprises 140,000 km2 of lowland floodplain of the upper Rio Paraguai basin that drains the Cerrado of central Brazil. The diverse mosaics of habitats resulting from the varied soil types and inundation regimes are responsible for an extraordinarily rich terrestrial and aquatic biota, exemplified by the bird richest wetland in the world—463 birds have been recorded there—and the largest known populations of several threatened mammals, such as Pampas deer ( Ozotoceros bezoarticus ), marsh deer ( Blastocerus dichotomus ), giant otter ( Pteronura brasiliensis ), and jaguar ( Panthera onca ). Until recently, deforestation of the adjoining Brazilian central plateau was considered the major threat to this area, but now deforestation is a critical problem within the floodplain itself. More than 40% of the forest and savanna habitats have been altered for cattle ranching through the introduction of exotic grasses. And there are other threats that lead to large-scale disruption of ecological processes, severely affecting biodiversity. Although the Pantanal wetland is a Biosphere Reserve and is considered a Wetland of International Importance, only 2.5% of the upper Paraguai River basin is formally protected. To date, protected areas have been created opportunistically and as such, although of undoubted value, protect only a fraction of the Pantanal's wildlife and habitats. Among the conservation initiatives in the area, the private sector is increasingly participating in the establishment of private reserves. The prospects are far from optimistic, however, and the major challenge is to find alternative socioeconomic models that allow for conservation and economic uses of the land in association with the development of specific environmental legislation that reflects the unique characteristics of the region.  相似文献   
30.
Remediation aimed at reducing human exposure to groundwater arsenic in West Bengal, one of the regions most impacted by this environmental hazard, are currently largely focussed on reducing arsenic in drinking water. Rice and cooking of rice, however, have also been identified as important or potentially important exposure routes. Quantifying the relative importance of these exposure routes is critically required to inform the prioritisation and selection of remediation strategies. The aim of our study, therefore, was to determine the relative contributions of drinking water, rice and cooking of rice to human exposure in three contrasting areas of West Bengal with different overall levels of exposure to arsenic, viz. high (Bhawangola-I Block, Murshidibad District), moderate (Chakdha Block, Nadia District) and low (Khejuri-I Block, Midnapur District). Arsenic exposure from water was highly variable, median exposures being 0.02 μg/kg/d (Midnapur), 0.77 μg/kg/d (Nadia) and 2.03 μg/kg/d (Murshidabad). In contrast arsenic exposure from cooked rice was relatively uniform, with median exposures being 0.30 μg/kg/d (Midnapur), 0.50 μg/kg/d (Nadia) and 0.84 μg/kg/d (Murshidabad). Cooking rice typically resulted in arsenic exposures of lower magnitude, indeed in Midnapur, median exposure from cooking was slightly negative. Water was the dominant route of exposure in Murshidabad, both water and rice were major exposure routes in Nadia, whereas rice was the dominant exposure route in Midnapur. Notwithstanding the differences in balance of exposure routes, median excess lifetime cancer risk for all the blocks were found to exceed the USEPA regulatory threshold target cancer risk level of 10−4–10−6. The difference in balance of exposure routes indicate a difference in balance of remediation approaches in the three districts.  相似文献   
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