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排序方式: 共有107条查询结果,搜索用时 928 毫秒
61.
HENRY LEE II DEBORAH A. REUSSER† JULIAN D. OLDEN‡ SCOTT S. SMITH† JIM GRAHAM§ VIRGINIA BURKETT JEFFREY S. DUKES†† ROBERT J. PIORKOWSKI‡‡ JOHN MCPHEDRAN§§ 《Conservation biology》2008,22(3):575-584
Abstract: Changes in temperature, precipitation, and other climatic drivers and sea-level rise will affect populations of existing native and non-native aquatic species and the vulnerability of aquatic environments to new invasions. Monitoring surveys provide the foundation for assessing the combined effects of climate change and invasions by providing baseline biotic and environmental conditions, although the utility of a survey depends on whether the results are quantitative or qualitative, and other design considerations. The results from a variety of monitoring programs in the United States are available in integrated biological information systems, although many include only non-native species, not native species. Besides including natives, we suggest these systems could be improved through the development of standardized methods that capture habitat and physiological requirements and link regional and national biological databases into distributed Web portals that allow drawing information from multiple sources. Combining the outputs from these biological information systems with environmental data would allow the development of ecological-niche models that predict the potential distribution or abundance of native and non-native species on the basis of current environmental conditions. Environmental projections from climate models can be used in these niche models to project changes in species distributions or abundances under altered climatic conditions and to identify potential high-risk invaders. There are, however, a number of challenges, such as uncertainties associated with projections from climate and niche models and difficulty in integrating data with different temporal and spatial granularity. Even with these uncertainties, integration of biological and environmental information systems, niche models, and climate projections would improve management of aquatic ecosystems under the dual threats of biotic invasions and climate change. 相似文献
62.
KATE A. HARDWICK PEGGY FIEDLER LYNDON C. LEE BRUCE PAVLIK RICHARD J. HOBBS JAMES ARONSON MARTIN BIDARTONDO ERIC BLACK DAVID COATES MATTHEW I. DAWS KINGSLEY DIXON STEPHEN ELLIOTT KERN EWING GEORGE GANN DAVID GIBBONS JOACHIM GRATZFELD MARTIN HAMILTON DAVID HARDMAN JIM HARRIS PAT M. HOLMES MEIRION JONES DAVID MABBERLEY ANDREW MACKENZIE CARLOS MAGDALENA ROBERT MARRS WILLIAM MILLIKEN ANTHONY MILLS EIMEAR NIC LUGHADHA MARGARET RAMSAY PAUL SMITH NIGEL TAYLOR CLARE TRIVEDI MICHAEL WAY OLIVER WHALEY STEPHEN D. HOPPER 《Conservation biology》2011,25(2):265-275
Abstract: Many of the skills and resources associated with botanic gardens and arboreta, including plant taxonomy, horticulture, and seed bank management, are fundamental to ecological restoration efforts, yet few of the world's botanic gardens are involved in the science or practice of restoration. Thus, we examined the potential role of botanic gardens in these emerging fields. We believe a reorientation of certain existing institutional strengths, such as plant‐based research and knowledge transfer, would enable many more botanic gardens worldwide to provide effective science‐based support to restoration efforts. We recommend botanic gardens widen research to include ecosystems as well as species, increase involvement in practical restoration projects and training practitioners, and serve as information hubs for data archiving and exchange. 相似文献
63.
为探究镉对胎儿肝脏发育的毒性作用.拟选用15只性成熟的8周龄的雌性C57BL/6小鼠,与雄鼠交配见栓后,于妊娠第7.5 d(Embryonic 7.5,E7.5)时,随机分为3组(每组5只),分别通过饮用水暴露法饲喂0、20和40 mg·L-1的氯化镉溶液,并于E14.5 d时收集各组小鼠的胎儿肝脏等组织.通过Ki67和TUNEL染色方法探究镉对不同性别胎鼠肝脏的增殖功能和凋亡功能的影响,并通过PCR芯片筛查和实时定量PCR方法检测镉处理组的雌性和雄性胎鼠肝脏中与细胞增殖和凋亡功能相关基因的表达变化.此外,我们还将通过石墨炉火焰原子吸收技术对镉处理组的雌性和雄性胎鼠的镉含量进行检测.结果显示:孕期低剂量镉暴露对胎儿体重、胎肝重量和肝脏指数均无显著性影响.在本实验条件下,镉对胎鼠肝脏的凋亡功能无显著性影响,但对增殖功能具有抑制作用,且该抑制作用具有雌性依赖性的特征.镉特异性诱导雌性胎鼠肝脏中NF1等多个细胞增殖功能相关基因以及TGF-β1信号通路分子的表达失衡;但对雄性胎鼠肝脏中相关基因的表达水平无显著性影响.镉在雌性胎儿组织中的积累量显著高于雄性胎儿组织.综上所述,孕期低剂量镉暴露特异性抑制雌性胎儿肝脏的细胞增殖功能,并诱导雌性胎儿肝脏中NF1等多个增殖功能相关基因以及TGF-β1信号通路分子的表达失衡,该性别依赖性的抑制作用可能与镉在雌性胎儿中相对较高的积累量相关. 相似文献
64.
65.
Various air pollution control (APC) techniques were employed in order to reduce emissions of air pollutants produced from
chemical plants, which have many different chemical production facilities. For an emission reduction of acid gases, this study
employed a method to improve solubility of pollutants by decreasing the operating temperature of the scrubbers, increasing
the surface area for effective contact of gas and liquid, and modifying processes in the acid scrubbers. To reduce emission
of both amines and acid gases, pollutant gas components were first separated, then condensation and/or acid scrubbing, depending
on the chemical and physical properties of pollutant components, were used. To reduce emission of solvents, condensation and
activated carbon adsorption were employed. To reduce emission of a mixture gases containing acid gases and solvents, the mixed
gases were passed into the first condenser, the acid scrubber, the second condenser, and the activated carbon adsorption tower
in sequence. As a strategy to reduce emission of pollutants at the source, this study also employed the simple pollution prevention
concept of modification of the previously operating APC control device. Finally, air emissions of pollutants produced from
the chemical plants were much more reduced by applying proper APC methods, depending upon the types (physical or chemical
properties) and the specific emission situations of pollutants. 相似文献
66.
Municipal solid waste landfills emit nitrous oxide (N2O) gas. Assuming that the soil cover is the primary N2O source from landfills, this study tested, during a four-year project, the hypothesis that the proper use of chosen soils with fine texture minimizes N2O emissions. A full-scale sanitary landfill, a full-scale bioreactor landfill and a cell planted with Nerium indicum or Festuca arundinacea Schreb, at the Hangzhou Tianziling landfill in Hangzhou City were the test sites. The N2O emission rates from all test sites were considerably lower than those reported in the published reports. Specifically, the N2O emission rate was dependent on soil water content and nitrate concentrations in the cover soil. The effects of leachate recirculation and irrigation were minimal. Properly chosen cover soils applied to the landfills reduced N2O flux. 相似文献
67.
The present study investigated the emissions of naphthalene and other compounds from several different moth repellents(MRs) and one toilet deodorant block(TDB)currently sold in Korea,using a headspace analysis.The emission factors and emission rates of naphthalene were studied using a small-scale environmental chamber.Paper-type products emitted a higher concentration of the total volatile organic compounds(VOCs)(normalized to the weight of test piece)than ball-type products,which in turn emitted higher ... 相似文献
68.
NAVJOT S. SODHI§ TIEN MING LEE LIAN PIN KOH† DEWI M. PRAWIRADILAGA‡ 《Conservation biology》2006,20(3):772-779
Abstract: Long-term (>50 years) extinction patterns and processes in isolated tropical forest patches are poorly understood. Considering that forest fragments are rapidly becoming the common feature of most tropical landscapes, data on the long-term conservation value of such fragments are urgently needed. We report on avifaunal turnover in a tropical woodlot (Bogor Botanical Gardens; 86 ha; 54% native and 46% introduced plants; mean 83,649 visitors/month) that has been surveyed several times before and after its isolation in 1936. By 2004 the original avifaunal richness of this woodlot declined by 59% (97 to 40 species) and its forest-dependent avifauna declined by 60% (30 to 12 species). Large-bodied birds were particularly prone to extinction before 1987, but following this time none of the species traits we studied could be considered predictive of extinction proneness. All seven forest-dependent bird species that attempted to colonize this woodlot by 1987 perished thereafter. Our results show that area reduction, isolation, intense human use, and perverse management (e.g., understory removal) of this patch have probably negatively affected the long-term sustainability of its forest avifauna. 相似文献
69.
Planning for Climate Change: Identifying Minimum-Dispersal Corridors for the Cape Proteaceae 总被引:10,自引:0,他引:10
PAUL WILLIAMS§§ LEE HANNAH† SANDY ANDELMAN‡ GUY MIDGLEY§ MIGUEL ARAÚJO††† GREG HUGHES§ LISA MANNE†† ENRIQUE MARTINEZ-MEYER‡‡ RICHARD PEARSON†† 《Conservation biology》2005,19(4):1063-1074
Abstract: Climate change poses a challenge to the conventional approach to biodiversity conservation, which relies on fixed protected areas, because the changing climate is expected to shift the distribution of suitable areas for many species. Some species will persist only if they can colonize new areas, although in some cases their dispersal abilities may be very limited. To address this problem we devised a quantitative method for identifying multiple corridors of connectivity through shifting habitat suitabilities that seeks to minimize dispersal demands first and then the area of land required. We applied the method to Proteaceae mapped on a 1-minute grid for the western part of the Cape Floristic Region of South Africa, to supplement the existing protected areas, using Worldmap software. Our goal was to represent each species in at least 35 grid cells (approximately 100 km2 ) at all times between 2000 and 2050 despite climate change. Although it was possible to achieve the goal at reasonable cost, caution will be needed in applying our method to reserves or other conservation investments until there is further information to support or refine the climate-change models and the species' habitat-suitability and dispersal models. 相似文献
70.
LIU Wen-ju Kim Kyoung-woong ZHU Yong-guan LEE Sang-woo CHANG Pei-chun Kwak Ji-hyun 《环境科学学报(英文版)》2006,18(2):287-291
This research includes two investigations. The first one is a market basket survey of the levels of arsenic (As) and trace elements in bracken fern (Pteridium aquilinum) originated from three countries: South Korea, China and North Korea. The results showed that the mean As concentrations in stems of samples were significantly higher than those in leaves. As concentrations in all samples did not exceed food safety limits for vegetables. Generally, concentrations of Fe, Mn, Cu and Zn in leaves were higher than those in stems. The second investigation is a survey on the levels of As and other heavy metals in vegetation in the vicinity of Myoungbong mine tailings. The results demonstrated that As, Pb and Cu concentrations and bioaccumulation factors (BCF) in seedlings of the fern(A splenium achilleifolium) were the highest, whereas Marsh horsetail(Equisetum polustre) accumulated the highest levels of Zn. Concentrations of As, Pb, Zn and Cu in vegetable-cress (Lepidium sativum) and the edible herb-aromatic madder (Elasholtzia splendens) were higher than food safety limits. Therefore, a risk assessment of As and other heavy metals in vegetables and herbs on local human health should be conducted in the future. 相似文献