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201.
Restoring Forests and Associated Ecosystem Services on Appalachian Coal Surface Mines 总被引:1,自引:0,他引:1
Zipper CE Burger JA Skousen JG Angel PN Barton CD Davis V Franklin JA 《Environmental management》2011,47(5):751-765
Surface coal mining in Appalachia has caused extensive replacement of forest with non-forested land cover, much of which is
unmanaged and unproductive. Although forested ecosystems are valued by society for both marketable products and ecosystem
services, forests have not been restored on most Appalachian mined lands because traditional reclamation practices, encouraged
by regulatory policies, created conditions poorly suited for reforestation. Reclamation scientists have studied productive
forests growing on older mine sites, established forest vegetation experimentally on recent mines, and identified mine reclamation
practices that encourage forest vegetation re-establishment. Based on these findings, they developed a Forestry Reclamation
Approach (FRA) that can be employed by coal mining firms to restore forest vegetation. Scientists and mine regulators, working
collaboratively, have communicated the FRA to the coal industry and to regulatory enforcement personnel. Today, the FRA is
used routinely by many coal mining firms, and thousands of mined hectares have been reclaimed to restore productive mine soils
and planted with native forest trees. Reclamation of coal mines using the FRA is expected to restore these lands’ capabilities
to provide forest-based ecosystem services, such as wood production, atmospheric carbon sequestration, wildlife habitat, watershed
protection, and water quality protection to a greater extent than conventional reclamation practices. 相似文献
202.
new habitats are created, community assembly may follow independent trajectories, since the relative importance of dispersal limitation, priority effects, species interactions, and environmental gradients can vary as assembly proceeds. Unfortunately, tracking community colonization and composition across decades is challenging. We compiled a multiyear community composition data set and reconstructed past communities with remains from sediment cores to investigate cladoceran assembly dynamics in six older (1920s) and two more recently formed (1950s) lakes. We found that current communities cluster along a gradient of thermal stratification that is known to influence predation intensity. Assembling communities showed evidence for a greater influence of species sorting and a reduced influence of spatial structure since the first colonizations. However, lake community trajectories varied considerably, reflecting different colonization sequences among lakes. In the older lakes, small-bodied cladocerans often arrived much earlier than large-bodied cladocerans, while the two younger lakes were colonized much more rapidly, and one was quickly dominated by a large-bodied species. Thus, by combining contemporary community data with paleoecological records, we show that assembly history influences natural community structure for decades while patterns of ecological sorting develop. 相似文献
203.
Being an archipelagic nation, the Philippines is susceptible and vulnerable to the ill-effects of weather-related hazards. Extreme weather events, which include tropical cyclones, monsoon rains and dry spells, have triggered hazards (such as floods and landslides) that have turned into disasters. Financial resources that were meant for development and social services have had to be diverted in response, addressing the destruction caused by calamities that beset different regions of the country. Changing climatic patterns and weather-related occurrences over the past five years (2004-08) may serve as an indicator of what climate change will mean for the country. Early recognition of this possibility and the implementation of appropriate action and measures, through disaster risk management, are important if loss of life and property is to be minimised, if not totally eradicated. This is a matter of urgent concern given the geographical location and geological characteristics of the Philippines. 相似文献
204.
Daniel Dvorett Joseph Bidwell Craig Davis Chris DuBois 《Environmental management》2013,52(4):1009-1022
The hydrogeomorphic approach (HGM) to wetland classification and functional assessment has been applied regionally throughout the United States, but the ability of HGM functional assessment models to reflect wetland condition has limited verification. Our objective was to determine how variability derived from anthropogenic effects and natural variability impacted site assessment variables within regional wetland subclasses in central Oklahoma. We collected data for nine potential assessment variables including vegetation physiognomy (e.g., tree basal area, herbaceous cover, canopy cover, etc.) and soil organic matter at wetlands of two HGM riverine subclasses (oxbow and riparian) in May and June, 2010. Using Akaike Information Criteria, we identified limited relationships between landscape disturbance metrics and assessment variables within subclasses. The high degree of natural variability from climatic and hydrologic factors within both subclasses may be masking the impact of landscape disturbance on the other measured assessment variables. Precipitation had significant effects on assessment variables within each of the subclasses. To reduce natural climatic variability, the reference domain may need to be further subdivided. The approach used in this study provides fairly rapid and quantitative methods for evaluating the effectiveness of using HGM assessment variables in assessing wetland condition regionally. 相似文献
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Summary What role should the United States play in the energy economy of the world? Do we want to be uninvolved? Do we sit back and
let the other industrial countries supply the rest of the world with nuclear power? Already, the world with four billion people
and too high a growth rate is headed for trouble that could engulf us all.
Four of five decades from now, when the population will have doubled to eight billion, the low sophistication level of today's
energy users will very likely have run the total energy use very high. We in the United States will not only have our own
energy problems; there will be an imperative need for a world energy policy, and we should be part of the negotiation. The
United States will have to be more than self-sufficient. Power from uranium and thorium will expectably be our backbone. both
at home and abroad.
Among other things, Americans cannot afford to have profligate worldwide use of fossil fuel, with the expected movement of
good crop weather northward, away from the best food-producing areas. American agriculture might be hit the hardest.
Problems like these are world problems, and they just won't go away. We are part of them. Is it not to our own interest to
have our own energy situation under control, so we can help shape the global outcome?
This article is reprinted (excerpted) with the permission of Education Development Center, Inc., from “The Case for Nuclear
Electric Power”, Occasional Paper No. 1 by Saville R. Davis and Jerrold R. Zacharias of the Energy in Perspective Project,
funded by the Business Roundtable, the John D. and Catherine T. MacArthur Foundation, and Massachusetts Institute of Technology,
For Biographic sketches of the Authors please see pages 305–306. 相似文献
209.
210.
Nudi AH de Luca Rebello Wagener A Francioni E de Lemos Scofield A Sette CB Veiga A 《Environment international》2007,33(3):315-327
This study is aimed at verifying the relevance of Ucides cordatus as a bioindicator of oil contamination and PAH bioavailability in mangrove sediments. For this, crabs and sediment cores were sampled from five mangroves, including an area suspected of contamination derived from an MF380 oil spillage, and analyzed for the 16 PAH in the USEPA priority list as well as for the five series of alkylated homologues. Concentrations in sediments varied from 35 microg kg-1 in the lower core layer of the control area to 33,000 microg kg-1 in the upper layer of the most contaminated area. Total PAH contents in crabs varied from 206 to 62,000 microg kg-1 and were closely correlated to that in sediments. In general, individual PAH profiles in both matrices were in good agreement. Phenanthrenes, however, were more predominant in crabs making up to 30-46% of the Total PAH. Accumulation factors found in the range of 0.7 to 35 were highly variable even after normalizing concentrations for organic carbon and lipid content. Survival in highly contaminated environment and reliable record of environmental contamination in the tissue provide evidence that U. cordatus is an excellent bioindicator for oil in mangroves. 相似文献