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151.
Spread of metals through an invertebrate food chain as influenced by a plant that hyperaccumulates nickel 总被引:6,自引:0,他引:6
Lynsey R. Peterson Victoria Trivett Alan J.M. Baker Carlos Aguiar A. Joseph Pollard 《Chemoecology》2003,13(2):103-108
Summary. Hyperaccumulation of metals in the shoot system of
plants is uncommon, yet taxonomically and geographically widespread. It
may have a variety of functions, including defense against herbivores.
This study investigated the effects of hyperaccumulation on metal
concentrations across trophic levels. We collected plant material, soil,
and invertebrates from Portuguese serpentine outcrops whose vegetation
is dominated by the nickel hyperaccumulator Alyssum pintodasilvae.
Samples were analyzed for nickel, chromium, and cobalt. Grasshoppers,
spiders, and other invertebrates collected from sites where A.
pintodasilvae was common had significantly elevated concentrations of
nickel, compared to nearby sites where this hyperaccumulator was not
found. Chromium and cobalt, occurring in high concentrations in the
serpentine soil but not accumulated by A. pintodasilvae, were not
elevated in the invertebrates. Therefore, it appears likely that a flux
of nickel to herbivore and carnivore trophic levels is specifically
facilitated by the presence of plants that hyperaccumulate this metal.
The results may be relevant to the development of phytoremediation and
phytomining technologies, which use plants to extract metals from the
soil.
Reveived 22 August 2002; accepted 2 April 2003.
R1D="
Correspondence to: A. J. Pollard, e-mail:joe.pollard@furman.edu 相似文献
152.
Sanitary landfills are the major method used today for the disposal and management of municipal solid waste. Decomposition of waste and rainfall generate leachate at the bottom of landfills, causing groundwater contamination. In this study, leachate from a municipal landfill site was treated by electrochemical oxidation in a pilot scale flow reactor, using oxide-coated titanium anode. The experiments were conducted under a constant flow rate of 2000 lh(-1) and the effect of current density on chemical oxygen demand, total organic carbon, color and ammonium removal was investigated. At a current density of 116.0 mA cm(-2) and 180 min of processing, the removal rates achieved were 73% for COD, 57% for TOC, 86% for color and 49% for ammonium. The process proved effective in degrading leachate, despite this effluent's usual refractoriness to treatment. 相似文献
153.
Peterson MM Horst GL Shea PJ Comfort SD Peterson RK 《Environmental pollution (Barking, Essex : 1987)》1996,93(1):57-62
Cost-effective and environmentally acceptable methods are needed to remediate munitions-contaminated soil. Some perennial grass species are tolerant of soil contaminants and may promote remediation because of their high water use and extensive fibrous root systems. The effects of 2,4,6-trinitrotoluene (TNT) and its reduction product, 4-amino-2,6-dinitrotoluene (4ADNT), on germination and early seedling development of tall fescue (Festuca arundinacea Schreb.) were determined. Tall fescue seeds were germinated in nutrient-free agar containing 0-60 mg TNT litre(-1) or 0-15 mg 4ADNT litre(-1). Germination decreased linearly as TNT concentration increased but was not significantly affected by 4ADNT at these concentrations. Concentrations less than 30 mg TNT litre(-1) or 7.5 mg 4ADNT litre(-1) had little effect on seedling growth and development. Higher TNT or 4ADNT concentrations substantially delayed seedling development, caused abnormal radicle tissue development, and reduced secondary root and shoot growth. Seedling respiration rates decreased linearly with increasing TNT concentration. Experiments indicate that tall fescue may be grown in soils that maintain soil solution concentrations of 30 mg TNT litre(-1) or less. 相似文献
154.
Denitrification across landscapes and waterscapes: a synthesis. 总被引:22,自引:0,他引:22
S Seitzinger J A Harrison J K B?hlke A F Bouwman R Lowrance B Peterson C Tobias G Van Drecht 《Ecological applications》2006,16(6):2064-2090
Denitrification is a critical process regulating the removal of bioavailable nitrogen (N) from natural and human-altered systems. While it has been extensively studied in terrestrial, freshwater, and marine systems, there has been limited communication among denitrification scientists working in these individual systems. Here, we compare rates of denitrification and controlling factors across a range of ecosystem types. We suggest that terrestrial, freshwater, and marine systems in which denitrification occurs can be organized along a continuum ranging from (1) those in which nitrification and denitrification are tightly coupled in space and time to (2) those in which nitrate production and denitrification are relatively decoupled. In aquatic ecosystems, N inputs influence denitrification rates whereas hydrology and geomorphology influence the proportion of N inputs that are denitrified. Relationships between denitrification and water residence time and N load are remarkably similar across lakes, river reaches, estuaries, and continental shelves. Spatially distributed global models of denitrification suggest that continental shelf sediments account for the largest portion (44%) of total global denitrification, followed by terrestrial soils (22%) and oceanic oxygen minimum zones (OMZs; 14%). Freshwater systems (groundwater, lakes, rivers) account for about 20% and estuaries 1% of total global denitrification. Denitrification of land-based N sources is distributed somewhat differently. Within watersheds, the amount of land-based N denitrified is generally highest in terrestrial soils, with progressively smaller amounts denitrified in groundwater, rivers, lakes and reservoirs, and estuaries. A number of regional exceptions to this general trend of decreasing denitrification in a downstream direction exist, including significant denitrification in continental shelves of N from terrestrial sources. Though terrestrial soils and groundwater are responsible for much denitrification at the watershed scale, per-area denitrification rates in soils and groundwater (kg N x km(-2) x yr(-1)) are, on average, approximately one-tenth the per-area rates of denitrification in lakes, rivers, estuaries, continental shelves, or OMZs. A number of potential approaches to increase denitrification on the landscape, and thus decrease N export to sensitive coastal systems exist. However, these have not generally been widely tested for their effectiveness at scales required to significantly reduce N export at the whole watershed scale. 相似文献
155.
Guntenspergen GR Peterson SA Leibowitz SG Cowardin LM 《Environmental monitoring and assessment》2002,78(3):229-252
We describe a study designed to evaluate the performance ofwetland condition indicators of the Prairie Pothole Region (PPR)of the north central United States. Basin and landscape scaleindicators were tested in 1992 and 1993 to determine theirability to discriminate between the influences of grasslanddominated and cropland dominated landscapes in the PPR. Pairedplots were selected from each of the major regions of the PPR.Among the landscape scale indicators tested, those most capableof distinguishing between the two landscapes were: 1) frequencyof drained wetland basins, 2) total length of drainage ditch perplot, 3) amount of exposed soil in the upland subject to erosion,4) indices of change in area of wetland covered by water, and5) number of breeding duck pairs. Basin scale indicators includingsoil phosphorus concentrations and invertebrate taxa richnessshowed some promise; however, plant species richness was the onlystatistically significant basin scale indicator distinguishinggrassland dominated from cropland dominated landscapes. Althoughour study found a number of promising candidate indicators, oneof our conclusions is that basin scale indicators present anumber of implementation problems, including: skill levelrequirements, site access denials, and recession of site accessby landowners. Alternatively, we suggest that the use oflandscape indicators based on remote sensing can be an effectivemeans of assessing wetland integrity. 相似文献
156.
The primary objective of this study was to evaluate temporal changes in heavy metal content of lower Columbia River sediment
following terminated or reduced soluble heavy metal loading from the world's largest lead-zinc refinery and mining districts
in the USA and Canada. Sediment cores were collected from two fine sediment depositional sites (∼600 km downstream) in August
1999 and were analyzed for total metal content, texture, and age/dating parameters. Zinc, cadmium and lead contents in 1999
declined by only a factor of two over their depth profile maxima (dated as between 1970 and 1980). In sharp contrast, more
than a 10-fold decrease in dissolved metal loading occurred during this same period. Zinc in filtered Columbia River water
at downstream locations also declined by > 10-fold, consistent with the reduced upper river solute-metal loading. Once soluble
metal releases are reduced or terminated, the solute half-time in Columbia River water is months versus ∼20 yr for adsorbed
metals on surficial (or resuspended) bed sediments. The much slower rate of decline for sediment, as compared to the solute
phase, is attributed to resuspension, transport and redeposition of irreversibly bound metals from upstream sedimentary deposits.
This implies downstream exposure of benthic or particle-ingesting biota can continue for years following source remediation
and/or termination of soluble metal releases. Accordingly, contaminant contents of both particulate and solute phases of river
water, as well as sediment core sections, are suggested for assessing long-term biotic exposure/response to mitigation activities
in the Columbia River and similar fluvial ecosystems. 相似文献
157.
158.
Portrayal of sustainability principles in the mission statements and on home pages of the world's largest organizations 下载免费PDF全文
Stephen T. Garnett Michael J. Lawes Robyn James Kristen Bigland Kerstin K. Zander 《Conservation biology》2016,30(2):297-307
Conservation can be achieved only if sustainability is embraced as core to organizational cultures. To test the extent to which the related concepts of sustainability, conservation, response to climate change, poverty alleviation, and gender equity have been incorporated into organizational culture, we compared mission statements published from 1990 to 2000 with those published in 2014 for 150 organzations, including conservation nongovernmental organizations (NGOs), aid NGOs, government development agencies, resource extraction companies, and retailers (30 in each category). We also analyzed the 2014 home web pages of each organization. Relative to the earlier period, the frequency with which mission statements mentioned poverty alleviation, biodiversity conservation, and a range of sustainable practices increased only slightly by 2014, particularly among resource extractors and retail companies. Few organizations in any sector had embedded either climate change or gender equity into their mission statements. In addition, the proportional intensity with which any of the aspirations were expressed did not change between periods. For current home pages, conservation NGOs, resource extractors, and government agencies were significantly more likely to acknowledge the importance of matters that were not part of their core business, but few aid agencies or retail companies promoted goals beyond alleviation of crises and profit maximization, respectively. Overall, there has been some progress in recognizing poverty alleviation, biodiversity conservation, and sustainable practices, but gender equity and a determination to reduce impacts on climate change are still rarely promoted as central institutional concerns. Sustainability in general, and biodiversity conservation in particular, will not be achieved unless their importance is more widely apparent in core communication products of organizations. 相似文献
159.
Carol P. Harden Anne Chin Mary R. English Rong Fu Kathleen A. Galvin Andrea K. Gerlak Patricia F. McDowell Dylan E. McNamara Jeffrey M. Peterson N. LeRoy Poff Eugene A. Rosa William D. Solecki Ellen E. Wohl 《Environmental management》2014,53(1):4-13
This article summarizes the primary outcomes of an interdisciplinary workshop in 2010, sponsored by the U.S. National Science Foundation, focused on developing key questions and integrative themes for advancing the science of human–landscape systems. The workshop was a response to a grand challenge identified recently by the U.S. National Research Council (2010a)—“How will Earth’s surface evolve in the “Anthropocene?”—suggesting that new theories and methodological approaches are needed to tackle increasingly complex human–landscape interactions in the new era. A new science of human–landscape systems recognizes the interdependence of hydro-geomorphological, ecological, and human processes and functions. Advances within a range of disciplines spanning the physical, biological, and social sciences are therefore needed to contribute toward interdisciplinary research that lies at the heart of the science. Four integrative research themes were identified—thresholds/tipping points, time scales and time lags, spatial scales and boundaries, and feedback loops—serving as potential focal points around which theory can be built for human–landscape systems. Implementing the integrative themes requires that the research communities: (1) establish common metrics to describe and quantify human, biological, and geomorphological systems; (2) develop new ways to integrate diverse data and methods; and (3) focus on synthesis, generalization, and meta-analyses, as individual case studies continue to accumulate. Challenges to meeting these needs center on effective communication and collaboration across diverse disciplines spanning the natural and social scientific divide. Creating venues and mechanisms for sustained focused interdisciplinary collaborations, such as synthesis centers, becomes extraordinarily important for advancing the science. 相似文献
160.
Jeffrey M. Peterson Marcellus M. Caldas Jason S. Bergtold Belinda S. Sturm Russell W. Graves Dietrich Earnhart Eric A. Hanley J. Christopher Brown 《Environmental management》2014,53(1):55-66
Many economic processes are intertwined with landscape change. A large number of individual economic decisions shape the landscape, and in turn the changes in the landscape shape economic decisions. This article describes key research questions about the economics of landscape change and reviews the state of research knowledge. The rich and varied economic–landscape interactions are an active area of research by economists, geographers, and others. Because the interactions are numerous and complex, disentangling the causal relationships in any given landscape system is a formidable research challenge. Limited data with mismatched temporal and spatial scales present further obstacles. Nevertheless, the growing body of economic research on these topics is advancing and shares fundamental challenges, as well as data and methods, with work in other disciplines. 相似文献