WorldWideScience

Sample records for ecological effects characterization

  1. Waianae Ecological Characterization Oahu, Hawaii 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Waianae Ecological Characterization is a digital synthesis of historical and current physical, ecological, and cultural information about the Waianae moku, which...

  2. Evaluate and characterize mechanisms controlling transport, fate, and effects of army smokes in the aerosol wind tunnel: Transport, transformations, fate, and terrestrial ecological effects of hexachloroethane obscurant smokes

    Energy Technology Data Exchange (ETDEWEB)

    Cataldo, D.A.; Ligotke, M.W.; Bolton, H. Jr.; Fellows, R.J.; Van Voris, P.; McVeety, B.D.; Li, Shu-mei W.; McFadden, K.M.

    1989-09-01

    The terrestrial transport, chemical fate, and ecological effects of hexachloroethane (HC) smoke were evaluated under controlled wind tunnel conditions. The primary objectives of this research program are to characterize and assess the impacts of smoke and obscurants on: (1) natural vegetation characteristic of US Army training sites in the United States; (2) physical and chemical properties of soils representative of these training sites; and (3) soil microbiological and invertebrate communities. Impacts and dose/responses were evaluated based on exposure scenarios, including exposure duration, exposure rate, and sequential cumulative dosing. Key to understanding the environmental impacts of HC smoke/obscurants is establishing the importance of environmental parameters such as relative humidity and wind speed on airborne aerosol characteristics and deposition to receptor surfaces. Direct and indirect biotic effects were evaluated using five plant species and two soil types. HC aerosols were generated in a controlled atmosphere wind tunnel by combustion of hexachloroethane mixtures prepared to simulate normal pot burn rates and conditions. The aerosol was characterized and used to expose plant, soil, and other test systems. Particle sizes of airborne HC ranged from 1.3 to 2.1 {mu}m mass median aerodynamic diameter (MMAD), and particle size was affected by relative humidity over a range of 20% to 85%. Air concentrations employed ranged from 130 to 680 mg/m{sup 3}, depending on exposure scenario. Chlorocarbon concentrations within smokes, deposition rates for plant and soil surfaces, and persistence were determined. The fate of principal inorganic species (Zn, Al, and Cl) in a range of soils was assessed.

  3. Evaluation Characterization of Mechanisms Controlling Fate and Effects of Army Smokes. (Transport, Transformations, Fate and Terrestrial Ecological Effects of Brass Obscurants).

    Science.gov (United States)

    1990-08-29

    Ecological Dose of Brass Flake Causing 50% Inhibition (EcDso) of Microbial Activity ................... 3.70 FIGURE 3.10 Ecological Dose of Brass Flake...diversity was determined by the procedure of Atlas (1 984a) and Atlas and Bartha (1987). Total heterotrophic bacteria were counted on Dlfcoo nutrient...0.99) 2515 (0.99) 1451 (0.97) 1335 (0.97) (a) EcDs 0 , the ecological concentration of brass flake causing 50% Inhibition of microbial parameter, was

  4. The ecological competition and grazing reverse the effects of sulfamethoxazole on plankton: a case study on characterizing community-level effect.

    Science.gov (United States)

    Wang, Changyou; Liang, Shengkang; Zhang, Yong

    2018-04-12

    The toxic effects of sulfamethoxazole (SMX) on densities of two algae, Platymonas helgolandica var. tsingtaoensis, Isochrysis galbana, and of a rotifer, Brachionus plicatilis, were tested by the population and community experiments. Two endpoints, the carrying capacity and the densities array of community in steady state (DACS), were used to characterize the toxic effects at a population level and a community one, respectively. The results showed that the carrying capacity of P. helgolandica var. tsingtaoensis and B. plicatilis did not decline significantly in population test when the concentration of SMX was lower than 6.0 mg L -1 and 12.0 mg L -1 , respectively. However, I. galbana was sensitive to SMX and had presented toxic effect at 3.0 mg L -1 . By extrapolation of toxic effect at a population level to a community one, a derived community-NOEC was 3.0 mg L -1 , representing an inference from data of toxic effects at population level. In community experiment, when the customized community was in steady state, the density of I. galbana increased as a whole with SMX concentration in the range of tested concentration (0-144 mg L -1 ), while that of P. helgolandica var. tsingtaoensis assumed the trend of a reversed "v" in this range. Only the density of B. plicatilis decreased with SMX concentration. With the DACS as endpoint, a NOEC for the customized community was determined to be 6.0 mg L -1 . This indicates that interspecific interactions can reverse the toxic effects of SMX on phytoplankton. The DACS was reliable and stable, serving as the endpoints in assessment of the effects of the pollutants on the ecosystems.

  5. Evaluate and characterize mechanisms controlling transport, fate and effects of army smokes in an aerosol wind tunnel: Transport, transformations, fate and terrestrial ecological effects of fog oil obscurant smokes: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Cataldo, D.A.; Van Voris, P.; Ligotke, M.W.; Fellows, R.J.; McVeety, B.D.; Li, Shu-mei W.; Bolton, H. Jr.; Fredrickson, J.K.

    1989-01-01

    The terrestrial transport, chemical fate, and ecological effects of fog oil (FO) smoke obscurants were evaluated under controlled wind tunnel conditions. The primary objectives of this research program are to characterize and assess the impacts of smoke and obscurants on: (1) natural vegetation characteristic of US Army training sites in the United States; (2) physical and chemical properties of soils representative of these training sites; and (3) soil microbiological and invertebrate communities. Impacts and dose/responses were evaluated based on an exposure scenario, including exposure duration, exposure rate, and sequential cumulative dosing. Key to understanding the environmental impacts of fog oil smoke/obscurants is establishing the importance of environmental parameters, such as relative humidity and wind speed on airborne aerosol characteristics and deposition to receptor surfaces. Direct and indirect biotic effects were evaluated using five plant species and three soil types. 29 refs., 35 figs., 32 tabs.

  6. School Effectiveness in Ecological Perspective.

    Science.gov (United States)

    Bronfenbrenner, Urie; Hamilton, Stephen F.

    This report focuses on the learning and development of primary and secondary school children, employing an "ecology of human development" model. This model is defined as involving the scientific study of the accommodation between growing human beings and the changing immediate settings in which they live and learn. The conceptual framework for the…

  7. Genetic Allee effects and their interaction with ecological Allee effects.

    Science.gov (United States)

    Wittmann, Meike J; Stuis, Hanna; Metzler, Dirk

    2018-01-01

    It is now widely accepted that genetic processes such as inbreeding depression and loss of genetic variation can increase the extinction risk of small populations. However, it is generally unclear whether extinction risk from genetic causes gradually increases with decreasing population size or whether there is a sharp transition around a specific threshold population size. In the ecological literature, such threshold phenomena are called 'strong Allee effects' and they can arise for example from mate limitation in small populations. In this study, we aim to (i) develop a meaningful notion of a 'strong genetic Allee effect', (ii) explore whether and under what conditions such an effect can arise from inbreeding depression due to recessive deleterious mutations, and (iii) quantify the interaction of potential genetic Allee effects with the well-known mate-finding Allee effect. We define a strong genetic Allee effect as a genetic process that causes a population's survival probability to be a sigmoid function of its initial size. The inflection point of this function defines the critical population size. To characterize survival-probability curves, we develop and analyse simple stochastic models for the ecology and genetics of small populations. Our results indicate that inbreeding depression can indeed cause a strong genetic Allee effect, but only if individuals carry sufficiently many deleterious mutations (lethal equivalents). Populations suffering from a genetic Allee effect often first grow, then decline as inbreeding depression sets in and then potentially recover as deleterious mutations are purged. Critical population sizes of ecological and genetic Allee effects appear to be often additive, but even superadditive interactions are possible. Many published estimates for the number of lethal equivalents in birds and mammals fall in the parameter range where strong genetic Allee effects are expected. Unfortunately, extinction risk due to genetic Allee effects

  8. Ecological Characterization Data for the 2004 Composite Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Downs, Janelle L.; Simmons, Mary A.; Stegen, Jennifer A.; Bunn, Amoret L.; Tiller, Brett L.; Thorsten, Susan L.; Zufelt, Rhett K.

    2004-11-01

    A composite analysis is required by U.S. Department of Energy (DOE) Order 435.1 to ensure public safety through the management of active and planned low-level radioactive waste disposal facilities associated with the Hanford Site. The original Hanford Site Composite Analysis of 1998 must be revised and submitted to DOE Headquarters (DOE-HQ) in 2004 because of revisions to waste site information in the 100, 200, and 300 Areas, updated performance assessments and environmental impact statements (EIS), changes in inventory estimates for key sites and constituents, and a change in the definition of offsite receptors. Beginning in fiscal year (FY) 2003, the DOE Richland Operations Office (DOE-RL) initiated activities, including the development of data packages, to support the 2004 Composite Analysis. This report describes the data compiled in FY 2003 to support ecological site assessment modeling for the 2004 Composite Analysis. This work was conducted as part of the Characterization of Systems Task of the Groundwater Remediation Project (formerly the Groundwater Protection Program) managed by Fluor Hanford, Inc., Richland, Washington. The purpose of this report is to provide summaries of the characterization information and available spatial data on the biological resources and ecological receptors found in the upland, riparian, aquatic, and island habitats on the Hanford Site. These data constitute the reference information used to establish parameters for the ecological risk assessment module of the System Assessment Capability and other assessment activities requiring information on the presence and distribution of biota on the Hanford Site.

  9. Ecological Characterization Data for the 2004 Composite Analysis

    International Nuclear Information System (INIS)

    Downs, Janelle L.; Simmons, Mary A.; Stegen, Amanda A.; Bunn, Amoret L.; Tiller, Brett L.; Thorsten, Susan L.; Zufelt, Rhett K.

    2004-01-01

    A composite analysis is required by U.S. Department of Energy (DOE) Order 435.1 to ensure public safety through the management of active and planned low-level radioactive waste disposal facilities associated with the Hanford Site. The original Hanford Site Composite Analysis of 1998 must be revised and submitted to DOE Headquarters (DOE-HQ) in 2004 because of revisions to waste site information in the 100, 200, and 300 Areas, updated performance assessments and environmental impact statements (EIS), changes in inventory estimates for key sites and constituents, and a change in the definition of offsite receptors. Beginning in fiscal year (FY) 2003, the DOE Richland Operations Office (DOE-RL) initiated activities, including the development of data packages, to support the 2004 Composite Analysis. This report describes the data compiled in FY 2003 to support ecological site assessment modeling for the 2004 Composite Analysis. This work was conducted as part of the Characterization of Systems Task of the Groundwater Remediation Project (formerly the Groundwater Protection Program) managed by Fluor Hanford, Inc., Richland, Washington. The purpose of this report is to provide/SUMmaries of the characterization information and available spatial data on the biological resources and ecological receptors found in the upland, riparian, aquatic, and island habitats on the Hanford Site. These data constitute the reference information used to establish parameters for the ecological risk assessment module of the System Assessment Capability and other assessment activities requiring information on the presence and distribution of biota on the Hanford Site

  10. Ecological effects of fuel cycle activities

    Energy Technology Data Exchange (ETDEWEB)

    Barnthouse, L; Cada, G; Kroodsma, R; Shriner, D; Tolbert, V; Turner, R

    1994-07-01

    The purpose of this paper is to summarize the approach used to characterize ecological impacts of the coal fuel cycle. The same approach is used for many of the impacts in other fuel cycles as well. The principal analytical approach being used in the study is an accounting framework - that is, a series of matrices that map each phase of the fuel cycle to a suite of possible. emissions, each emission to a suite of impact categories, and each impact category to an external cost. This paper summarizes the ecological impacts of all phases of the coal fuel cycle, defines the ecological impact categories used in the study's 'accounting framework', and discusses alternative approaches to quantification. Externalities associated with CO{sub 2}-induced global climate change are beyond the scope of this paper and are not discussed.

  11. Ecological effects of fuel cycle activities

    International Nuclear Information System (INIS)

    Barnthouse, L.; Cada, G.; Kroodsma, R.; Shriner, D.; Tolbert, V.; Turner, R.

    1994-01-01

    The purpose of this paper is to summarize the approach used to characterize ecological impacts of the coal fuel cycle. The same approach is used for many of the impacts in other fuel cycles as well. The principal analytical approach being used in the study is an accounting framework - that is, a series of matrices that map each phase of the fuel cycle to a suite of possible. emissions, each emission to a suite of impact categories, and each impact category to an external cost. This paper summarizes the ecological impacts of all phases of the coal fuel cycle, defines the ecological impact categories used in the study's 'accounting framework', and discusses alternative approaches to quantification. Externalities associated with CO 2 -induced global climate change are beyond the scope of this paper and are not discussed

  12. Ecological effects of contaminants and remedial actions in Bear Creek

    Energy Technology Data Exchange (ETDEWEB)

    Southworth, G.R.; Loar, J.M.; Ryon, M.G.; Smith, J.G.; Stewart, A.J. (Oak Ridge National Lab., TN (United States)); Burris, J.A. (C. E. Environmental, Inc., Tallahassee, FL (United States))

    1992-01-01

    Ecological studies of the Bear Creek watershed, which drains the area surrounding several Oak Ridge Y-12 Plant waste disposal facilities, were initiated in May 1984 and are continuing at present. These studies consisted of an initial, detailed characterization of the benthic invertebrate and fish communities in Bear Creek, and they were followed by a presently ongoing monitoring phase that involves reduced sampling intensities. The characterization phase utilized two approaches: (1) instream sampling of benthic invertebrate and fish communities in Bear Creek to identify spatial and temporal patterns in distribution and abundance and (2) laboratory bioassays on water samples from Bear Creek and selected tributaries to identify potential sources of toxicity to biota. The monitoring phase of the ecological program relates to the long-term goals of identifying and prioritizing contaminant sources and assessing the effectiveness of remedial actions. It continues activities of the characterization phase at less frequent intervals. The Bear Greek Valley is a watershed that drains the area surrounding several closed Oak Ridge Y-12 Plant waste disposal facilities. Past waste disposal practices in Bear Creek Valley resulted in contamination of Bear Creek and consequent ecological damage. Extensive remedial actions have been proposed at waste sites, and some of the have been implemented or are now underway. The proposed study plan consists of an initial, detailed characterization of the benthic invertebrate and fish communities in Bear Creek in the first year followed by a reduction in sampling intensity during the monitoring phase of the plan. The results of sampling conducted from May 1984 through early 1989 are presented in this report.

  13. Ecological effects of contaminants and remedial actions in Bear Creek

    International Nuclear Information System (INIS)

    Southworth, G.R.; Loar, J.M.; Ryon, M.G.; Smith, J.G.; Stewart, A.J.; Burris, J.A.

    1992-01-01

    Ecological studies of the Bear Creek watershed, which drains the area surrounding several Oak Ridge Y-12 Plant waste disposal facilities, were initiated in May 1984 and are continuing at present. These studies consisted of an initial, detailed characterization of the benthic invertebrate and fish communities in Bear Creek, and they were followed by a presently ongoing monitoring phase that involves reduced sampling intensities. The characterization phase utilized two approaches: (1) instream sampling of benthic invertebrate and fish communities in Bear Creek to identify spatial and temporal patterns in distribution and abundance and (2) laboratory bioassays on water samples from Bear Creek and selected tributaries to identify potential sources of toxicity to biota. The monitoring phase of the ecological program relates to the long-term goals of identifying and prioritizing contaminant sources and assessing the effectiveness of remedial actions. It continues activities of the characterization phase at less frequent intervals. The Bear Greek Valley is a watershed that drains the area surrounding several closed Oak Ridge Y-12 Plant waste disposal facilities. Past waste disposal practices in Bear Creek Valley resulted in contamination of Bear Creek and consequent ecological damage. Extensive remedial actions have been proposed at waste sites, and some of the have been implemented or are now underway. The proposed study plan consists of an initial, detailed characterization of the benthic invertebrate and fish communities in Bear Creek in the first year followed by a reduction in sampling intensity during the monitoring phase of the plan. The results of sampling conducted from May 1984 through early 1989 are presented in this report

  14. Habitat characterization of the Tortugas Ecological Reserve south using photographic and quadrat methods

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — We supply habitat characterization data along a single randomly oriented transect at each of 16 sampling stations in the Tortugas South Ecological Reserve. This...

  15. Habitat characterization of the Tortugas Ecological Reserve south using photographic and quadrat methods.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — We supply habitat characterization data along a single randomly oriented transect at each of 16 sampling stations in the Tortugas South Ecological Reserve. This...

  16. Ecology

    Science.gov (United States)

    Ternjej, Ivancica; Mihaljevic, Zlatko

    2017-10-01

    Ecology is a science that studies the mutual interactions between organisms and their environment. The fundamental subject of interest in ecology is the individual. Topics of interest to ecologists include the diversity, distribution and number of particular organisms, as well as cooperation and competition between organisms, both within and among ecosystems. Today, ecology is a multidisciplinary science. This is particularly true when the subject of interest is the ecosystem or biosphere, which requires the knowledge and input of biologists, chemists, physicists, geologists, geographists, climatologists, hydrologists and many other experts. Ecology is applied in a science of restoration, repairing disturbed sites through human intervention, in natural resource management, and in environmental impact assessments.

  17. Ecological effect of rare earth elements

    International Nuclear Information System (INIS)

    Hu Aitang; Zhou Quansuo; Zheng Shaojian; Zhai Hai; Zhao Xiulan; Pang Yonglin; Wang Yuqi; Sun Jingxin; Zhang Shen; Wang Lijun

    1997-01-01

    Water and soil culture were carried out to study the ecological effect of rare earth elements (REEs) in the aspect of plant-soil system. Contents of REEs were determined by instrumental neutron activation analysis (INAA). There was a limit to REEs-tolerance of crops, which differed with the development periods of plant and soil types. The REEs concentration in plant, especially in root, was marked related to the concentration in culture material. Beyond the concentration-limit appeared phototoxicity. The chemical behavior of REEs in plants and soils varied with soil types and elements. The bio-availability of REEs in soil mainly depended on the exchangeable fraction of REEs affected strongly by the physi-chemical properties of soils

  18. Technical Overview of Ecological Risk Assessment - Analysis Phase: Exposure Characterization

    Science.gov (United States)

    Exposure Characterization is the second major component of the analysis phase of a risk assessment. For a pesticide risk assessment, the exposure characterization describes the potential or actual contact of a pesticide with a plant, animal, or media.

  19. Effects of Global Warming on Vibrio Ecology.

    Science.gov (United States)

    Vezzulli, Luigi; Pezzati, Elisabetta; Brettar, Ingrid; Höfle, Manfred; Pruzzo, Carla

    2015-06-01

    Vibrio-related infections are increasing worldwide both in humans and aquatic animals. Rise in global sea surface temperature (SST), which is approximately 1 °C higher now than 140 years ago and is one of the primary physical impacts of global warming, has been linked to such increases. In this chapter, major known effects of increasing SST on the biology and ecology of vibrios are described. They include the effects on bacterial growth rate, both in the field and in laboratory, culturability, expression of pathogenicity traits, and interactions with aquatic organisms and abiotic surfaces. Special emphasis is given to the effect of ocean warming on Vibrio interactions with zooplankters, which represent one of the most important aquatic reservoirs for these bacteria. The reported findings highlight the biocomplexity of the interactions between vibrios and their natural environment in a climate change scenario, posing the need for interdisciplinary studies to properly understand the connection between ocean warming and persistence and spread of vibrios in sea waters and the epidemiology of the diseases they cause.

  20. Ecology

    International Nuclear Information System (INIS)

    Kalusche, D.

    1978-01-01

    The book turns to the freshment, the teacher, for preparation of ecological topics for lessons, but also to pupils of the secondary stage II, and the main course ecology. The book was knowingly held simple with the restriction to: the ecosystem and its abiotic basic functions, simple articles on population biology, bioceonotic balance ith the questions of niche formation and the life form types coherent with it, of the substance and energy household, the production biology and space-wise and time-wise differentations within an ecological system form the main points. A central role in the volume is given to the illustrations. Their variety is to show and deepen the coherences shown. (orig./HP) [de

  1. The Ecological effect of conveyance pipeline from Gurara reservoir ...

    African Journals Online (AJOL)

    The study focuses on the public awareness of the effect of conveyance pipeline from Gurara reservoir to lower Usman Dam on Ecological degradation in Abuja, using data from questionnaire survey of about 150 households as well as field observation. The data from the survey reveals that over 30% ecological degradations ...

  2. Pitfalls in ecological research - transgenerational effects

    Czech Academy of Sciences Publication Activity Database

    Latzel, Vít

    2015-01-01

    Roč. 50, č. 1 (2015), s. 75-85 ISSN 1211-9520 R&D Projects: GA ČR(CZ) GA14-06802S Institutional support: RVO:67985939 Keywords : ecology * epigenetics * evolution Subject RIV: EF - Botanics Impact factor: 1.433, year: 2015

  3. [Connotation characterization and evaluation of ecological well-being based on ecosystem service theory.

    Science.gov (United States)

    Zang, Zheng; Zou, Xin- Qing

    2016-04-22

    China is advocating ecological civilization construction nowadays. Further researches on the relation between ecosystem service and humanity well-being are full of theoretical and practical significance. Combining related researches, this paper defined the concept and connotation of ecological well-being based on ecosystem service theory. Referencing theory of national economic accounting and relative researches, the evaluation indicators of ecological well-being supply and consumption were established. The quantitative characterization and evaluation method of red line of regional ecological well-being was proposed on the basis of location quotient. Then the evaluation of ecological well-being in mainland China in 2012 was set as an example for empirical research. The results showed that the net product values of 6 ecosystems, includingcultivated land, forest land, grassland, wetland, water area and unused land, were respectively 1481.925, 8194.806, 4176.277, 4245.760, 3177.084 and 133.762 billion CNY. Spatial heterogeneity of ecosystem net product in different provinces was distinct. Ecological well-being per capita of forest land, grassland, wetland, cultivated land and unused land in eastern and middle provinces were under the red line and less than the national average. The spatial distribution of 9 kinds of ecological well-being per capita split at Hu's line with high value in northwest and low value in southeast, and was aggravated by differences in density of population and land resources gift.

  4. The potential to characterize ecological data with terrestrial laser scanning in Harvard Forest, MA

    Science.gov (United States)

    Boucher, P.; Saenz, E.; Li, Z.

    2018-01-01

    Contemporary terrestrial laser scanning (TLS) is being used widely in forest ecology applications to examine ecosystem properties at increasing spatial and temporal scales. Harvard Forest (HF) in Petersham, MA, USA, is a long-term ecological research (LTER) site, a National Ecological Observatory Network (NEON) location and contains a 35 ha plot which is part of Smithsonian Institution's Forest Global Earth Observatory (ForestGEO). The combination of long-term field plots, eddy flux towers and the detailed past historical records has made HF very appealing for a variety of remote sensing studies. Terrestrial laser scanners, including three pioneering research instruments: the Echidna Validation Instrument, the Dual-Wavelength Echidna Lidar and the Compact Biomass Lidar, have already been used both independently and in conjunction with airborne laser scanning data and forest census data to characterize forest dynamics. TLS approaches include three-dimensional reconstructions of a plot over time, establishing the impact of ice storm damage on forest canopy structure, and characterizing eastern hemlock (Tsuga canadensis) canopy health affected by an invasive insect, the hemlock woolly adelgid (Adelges tsugae). Efforts such as those deployed at HF are demonstrating the power of TLS as a tool for monitoring ecological dynamics, identifying emerging forest health issues, measuring forest biomass and capturing ecological data relevant to other disciplines. This paper highlights various aspects of the ForestGEO plot that are important to current TLS work, the potential for exchange between forest ecology and TLS, and emphasizes the strength of combining TLS data with long-term ecological field data to create emerging opportunities for scientific study. PMID:29503723

  5. The potential to characterize ecological data with terrestrial laser scanning in Harvard Forest, MA.

    Science.gov (United States)

    Orwig, D A; Boucher, P; Paynter, I; Saenz, E; Li, Z; Schaaf, C

    2018-04-06

    Contemporary terrestrial laser scanning (TLS) is being used widely in forest ecology applications to examine ecosystem properties at increasing spatial and temporal scales. Harvard Forest (HF) in Petersham, MA, USA, is a long-term ecological research (LTER) site, a National Ecological Observatory Network (NEON) location and contains a 35 ha plot which is part of Smithsonian Institution's Forest Global Earth Observatory (ForestGEO). The combination of long-term field plots, eddy flux towers and the detailed past historical records has made HF very appealing for a variety of remote sensing studies. Terrestrial laser scanners, including three pioneering research instruments: the Echidna Validation Instrument, the Dual-Wavelength Echidna Lidar and the Compact Biomass Lidar, have already been used both independently and in conjunction with airborne laser scanning data and forest census data to characterize forest dynamics. TLS approaches include three-dimensional reconstructions of a plot over time, establishing the impact of ice storm damage on forest canopy structure, and characterizing eastern hemlock ( Tsuga canadensis ) canopy health affected by an invasive insect, the hemlock woolly adelgid ( Adelges tsugae ). Efforts such as those deployed at HF are demonstrating the power of TLS as a tool for monitoring ecological dynamics, identifying emerging forest health issues, measuring forest biomass and capturing ecological data relevant to other disciplines. This paper highlights various aspects of the ForestGEO plot that are important to current TLS work, the potential for exchange between forest ecology and TLS, and emphasizes the strength of combining TLS data with long-term ecological field data to create emerging opportunities for scientific study.

  6. Ecological and evolutionary effects of stickleback on community structure.

    Directory of Open Access Journals (Sweden)

    Simone Des Roches

    Full Text Available Species' ecology and evolution can have strong effects on communities. Both may change concurrently when species colonize a new ecosystem. We know little, however, about the combined effects of ecological and evolutionary change on community structure. We simultaneously examined the effects of top-predator ecology and evolution on freshwater community parameters using recently evolved generalist and specialist ecotypes of three-spine stickleback (Gasterosteus aculeatus. We used a mesocosm experiment to directly examine the effects of ecological (fish presence and density and evolutionary (phenotypic diversity and specialization factors on community structure at lower trophic levels. We evaluated zooplankton biomass and composition, periphyton and phytoplankton chlorophyll-a concentration, and net primary production among treatments containing different densities and diversities of stickleback. Our results showed that both ecological and evolutionary differences in the top-predator affect different aspects of community structure and composition. Community structure, specifically the abundance of organisms at each trophic level, was affected by stickleback presence and density, whereas composition of zooplankton was influenced by stickleback diversity and specialization. Primary productivity, in terms of chlorophyll-a concentration and net primary production was affected by ecological but not evolutionary factors. Our results stress the importance of concurrently evaluating both changes in density and phenotypic diversity on the structure and composition of communities.

  7. Characterization of the ecological interactions of Roundup Ready 2 Yield® soybean, MON 89788, for use in ecological risk assessment.

    Science.gov (United States)

    Horak, Michael J; Rosenbaum, Eric W; Phillips, Samuel L; Kendrick, Daniel L; Carson, David; Clark, Pete L; Nickson, Thomas E

    2015-01-01

    As part of an ecological risk assessment, Roundup Ready 2 Yield® soybean (MON 89788) was compared to a conventional control soybean variety, A3244, for disease and arthropod damage, plant response to abiotic stress and cold, effects on succeeding plant growth (allelopathic effects), plant response to a bacterial symbiont, and effects on the ability of seed to survive and volunteer in a subsequent growing season. Statistically significant differences between MON 89788 and A3244 were considered in the context of the genetic variation known to occur in soybean and were assessed for their potential impact on plant pest (weed) potential and adverse environmental impact. The results of these studies revealed no effects of the genetic modification that would result in increased pest potential or adverse environmental impact of MON 89788 compared with A3244. This paper illustrates how such characterization studies conducted in a range of environments where the crop is grown are used in an ecological risk assessment of the genetically modified (GM) crop. Furthermore, risk assessors and decision makers use this information when deciding whether to approve a GM crop for cultivation in-or grain import into-their country.

  8. Ecological effects of transuranics in the terrestrial environment

    International Nuclear Information System (INIS)

    Whicker, F.W.

    1980-01-01

    This chapter explores the ecological effects of transuranium radionuclides in terrestrial environments. No direct studies that relate the level of transuranic contamination to specific changes in structure or function of ecological systems have been carried out. The only alternative approach presently available is to infer such relationships from observations of biota in contaminated environments and models. Advantages and shortcomings of these observations as well as those of the direct experimental approach are discussed

  9. Linking effects of anthropogenic debris to ecological impacts.

    Science.gov (United States)

    Browne, Mark Anthony; Underwood, A J; Chapman, M G; Williams, Rob; Thompson, Richard C; van Franeker, Jan A

    2015-05-22

    Accelerated contamination of habitats with debris has caused increased effort to determine ecological impacts. Strikingly, most work on organisms focuses on sublethal responses to plastic debris. This is controversial because (i) researchers have ignored medical insights about the mechanisms that link effects of debris across lower levels of biological organization to disease and mortality, and (ii) debris is considered non-hazardous by policy-makers, possibly because individuals can be injured or removed from populations and assemblages without ecological impacts. We reviewed the mechanisms that link effects of debris across lower levels of biological organization to assemblages and populations. Using plastic, we show microplastics reduce the 'health', feeding, growth and survival of ecosystem engineers. Larger debris alters assemblages because fishing-gear and tyres kill animals and damage habitat-forming plants, and because floating bottles facilitate recruitment and survival of novel taxa. Where ecological linkages are not known, we show how to establish hypothetical links by synthesizing studies to assess the likelihood of impacts. We also consider how population models examine ecological linkages and guide management of ecological impacts. We show that by focusing on linkages to ecological impacts rather than the presence of debris and its sublethal impacts, we could reduce threats posed by debris. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  10. Linking effects of anthropogenic debris to ecological impacts

    Science.gov (United States)

    Browne, Mark Anthony; Underwood, A. J.; Chapman, M. G.; Williams, Rob; Thompson, Richard C.; van Franeker, Jan A.

    2015-01-01

    Accelerated contamination of habitats with debris has caused increased effort to determine ecological impacts. Strikingly, most work on organisms focuses on sublethal responses to plastic debris. This is controversial because (i) researchers have ignored medical insights about the mechanisms that link effects of debris across lower levels of biological organization to disease and mortality, and (ii) debris is considered non-hazardous by policy-makers, possibly because individuals can be injured or removed from populations and assemblages without ecological impacts. We reviewed the mechanisms that link effects of debris across lower levels of biological organization to assemblages and populations. Using plastic, we show microplastics reduce the ‘health’, feeding, growth and survival of ecosystem engineers. Larger debris alters assemblages because fishing-gear and tyres kill animals and damage habitat-forming plants, and because floating bottles facilitate recruitment and survival of novel taxa. Where ecological linkages are not known, we show how to establish hypothetical links by synthesizing studies to assess the likelihood of impacts. We also consider how population models examine ecological linkages and guide management of ecological impacts. We show that by focusing on linkages to ecological impacts rather than the presence of debris and its sublethal impacts, we could reduce threats posed by debris. PMID:25904661

  11. Ecological effects of exposure to enhanced levels of ionizing radiation.

    Science.gov (United States)

    Geras'kin, Stanislav A

    2016-10-01

    Irradiation of plants and animals can result in disruption of ecological relationships between the components of ecosystems. Such effects may act as triggers of perturbation and lead to consequences that may differ essentially from expected ones based on effects observed at the organismal level. Considerable differences in ecology and niches occupied by different species lead to substantial differences in doses of ionizing radiation absorbed by species, even when they all are present in the same environment at the same time. This is especially evident for contamination with α-emitting radionuclides. Radioactive contamination can be considered an ecological factor that is able to modify the resistance in natural populations. However, there are radioecological situations when elevated radioresistance does not evolve or persist. The complexity and non-linearity of the structure and functioning of ecosystems can lead to unexpected consequences of stress effects, which would appear harmless if they were assessed within the narrower context of organism-based traditional radioecology. Therefore, the use of ecological knowledge is essential for understanding responses of populations and ecosystems to radiation exposure. Integration of basic ecological principles in the design and implementation of radioecological research is essential for predicting radiation effects under rapidly changing environmental conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. The Effect of Size and Ecology on Extinction Susceptibility

    Science.gov (United States)

    Huynh, C.; Yuan, A.; Heim, N.; Payne, J.

    2015-12-01

    Although life on Earth first emerged as prokaryotic organisms, it eventually evolved into billions of different species. However, extinctions on Earth, especially the five mass extinctions, have decimated species. So what leads to a species survival or demise during a mass extinction? Are certain species more susceptible to extinctions based on their size and ecology? For this project, we focused on the data of marine animals. To examine the impact of size and ecology on a species's likelihood of survival, we compared the sizes and ecologies of the survivors and victims of the five mass extinctions. The ecology, or life mode, of a genus consists of the combination of tiering, motility, and feeding mechanism. Tiering refers to the animal's typical location in the water column and sediments, motility refers to its ability to move, and feeding mechanism describes the way the organism eats; together, they describe the animal's behavior. We analyzed the effect of ecology on survival using logistic regression, which compares life mode to the success or failure of a genus during each mass extinction interval. For organism size, we found the extinct organisms' mean size (both volume and length) and compared it with the average size of survivors on a graph. Our results show that while surviving genera of mass extinctions tended to be slightly larger than those that went extinct, there was no significant difference. Even though the Permian (Changhsingian) and Triassic (Rhaetian) extinctions had larger surviving species, likewise the difference was small. Ecology had a more obvious impact on the likelihood of survival; fast-moving, predatory pelagic organisms were the most likely to go extinct, while sedentary, infaunal suspension feeders had the greatest chances of survival. Overall, ecology played a greater role than size in determining the survival of a species. With this information, we can use ecology to predict which species would survive future extinctions.

  13. Ecological effectiveness as an essential quality requirement of innovational construction

    Directory of Open Access Journals (Sweden)

    Mkrtchyan Tamara

    2017-01-01

    Full Text Available Nowadays it seems to be very essential to develop national construction industry by implementation of innovative technologies. As an object of innovational construction «Smart house» or «green building» demonstrates the latest advances in ecological building materials, energy-saving structures and lean-technologies. According to the concept of TQM «green building» has tube compatible with environmental protection, environment sustainability and ecological effectiveness requirements. «Green certification» includes these terms into the National environment sustainability rating system. The main goal of this research work was to review and compare theoretical models and concepts of effectiveness and analyze their applicability to determine the term ecological effectiveness as the main Quality Score.

  14. Overview of climate information needs for ecological effects models

    Energy Technology Data Exchange (ETDEWEB)

    Peer, R.L.

    1990-01-01

    Atmospheric scientists engaged in climate change research require a basic understanding of how ecological effects models incorporate climate. The report provides an overview of existing ecological models that might be used to model climate change effects on vegetation. Some agricultural models and statistical methods are also discussed. The weather input data requirements, weather simulation methods, and other model characteristics relevant to climate change research are described for a selected number of models. The ecological models are classified as biome, ecosystem, or tree models; the ecosystem models are further subdivided into species dynamics or process models. In general, ecological modelers have had to rely on readily available meteorological data such as temperature and rainfall. Although models are becoming more sophisticated in their treatment of weather and require more kinds of data (such as wind, solar radiation, or potential evapotranspiration), modelers are still hampered by a lack of data for many applications. Future directions of ecological effects models and the climate variables that will be required by the models are discussed.

  15. Epidemiological and Ecological Characterization of the EHEC O104:H4 Outbreak in Hamburg, Germany, 2011.

    Directory of Open Access Journals (Sweden)

    Maike Tahden

    Full Text Available In 2011, a large outbreak of entero-hemorrhagic E. coli (EHEC and hemolytic uremic syndrome (HUS occurred in Germany. The City of Hamburg was the first focus of the epidemic and had the highest incidences among all 16 Federal States of Germany. In this article, we present epidemiological characteristics of the Hamburg notification data. Evaluating the epicurves retrospectively, we found that the first epidemiological signal of the outbreak, which was in form of a HUS case cluster, was received by local health authorities when already 99 EHEC and 48 HUS patients had experienced their first symptoms. However, only two EHEC and seven HUS patients had been notified. Middle-aged women had the highest risk for contracting the infection in Hamburg. Furthermore, we studied timeliness of case notification in the course of the outbreak. To analyze the spatial distribution of EHEC/HUS incidences in 100 districts of Hamburg, we mapped cases' residential addresses using geographic information software. We then conducted an ecological study in order to find a statistical model identifying associations between local socio-economic factors and EHEC/HUS incidences in the epidemic. We employed a Bayesian Poisson model with covariates characterizing the Hamburg districts as well as incorporating structured and unstructured spatial effects. The Deviance Information Criterion was used for stepwise variable selection. We applied different modeling approaches by using primary data, transformed data, and preselected subsets of transformed data in order to identify socio-economic factors characterizing districts where EHEC/HUS outbreak cases had their residence.

  16. Microbial ecology-based methods to characterize the bacterial communities of non-model insects.

    Science.gov (United States)

    Prosdocimi, Erica M; Mapelli, Francesca; Gonella, Elena; Borin, Sara; Crotti, Elena

    2015-12-01

    Among the animals of the Kingdom Animalia, insects are unparalleled for their widespread diffusion, diversity and number of occupied ecological niches. In recent years they have raised researcher interest not only because of their importance as human and agricultural pests, disease vectors and as useful breeding species (e.g. honeybee and silkworm), but also because of their suitability as animal models. It is now fully recognized that microorganisms form symbiotic relationships with insects, influencing their survival, fitness, development, mating habits and the immune system and other aspects of the biology and ecology of the insect host. Thus, any research aimed at deepening the knowledge of any given insect species (perhaps species of applied interest or species emerging as novel pests or vectors) must consider the characterization of the associated microbiome. The present review critically examines the microbiology and molecular ecology techniques that can be applied to the taxonomical and functional analysis of the microbiome of non-model insects. Our goal is to provide an overview of current approaches and methods addressing the ecology and functions of microorganisms and microbiomes associated with insects. Our focus is on operational details, aiming to provide a concise guide to currently available advanced techniques, in an effort to extend insect microbiome research beyond simple descriptions of microbial communities. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Soedra's ecological forest management plans. Effects on production and economy

    International Nuclear Information System (INIS)

    Viklund, E.

    1998-01-01

    In 1995 SOEDRA Skog, Sweden's largest forest owners association, started making ecological forest management plans, Groena skogsbruksplaner. The ecological forest management plans are divided into different compartments in which the management is adapted to the present ecological conditions. The stands are divided into four different categories depending on the different values of nature conservation. The object of this study was to find an easy method to quantify and describe the effects of nature conservation on economy and forest production in SOEDRA:s ecological forest management plans. The developed and purposed method, called PLAN-metoden, does not consider the interests, measures beyond the period of the plan, or losses due to snow or wind. It calculates the difference between the purposed measures in the ecological management plan and an alternative with management according to the requirements of the present Forestry Act. The economic effects of nature conservation varies between a net profit of 0,3% and a cost of 9,1% when calculated with the cash-flow method. The average decrease of possible cutting of merchantable timber was 11,3% and varies between 3,1 and 32,9%. The average decrease of cutting possibilities was 12,9% and varies between a decrease of 0,7% and a decrease of 28,3% when calculated with a present value method. Mainly mature, well-stocked compartments, which are considered not to be managed in the future, give rise to high costs. Properties with unprofitable thinnings and costly scarification, regeneration and cleaning seem to be favoured by the nature conservation in the plans. The Ecological management plans are expected to be of great importance to the members of SOEDRA. The interest in nature conservation is larger than that of economical issues. In order to avoid unsatisfactory results the planning should be accomplished in close personal contact with the forest owner Examination paper 1998-1. 21 refs, 2 figs, 39 tabs

  18. Bioremediation: Effectiveness in reducing the ecological impact

    International Nuclear Information System (INIS)

    Scholten, M.C.T.

    1992-01-01

    Bioremediation becomes an important technique in oil spill combat programmes. The purpose is to shorten the exposure time of biota to oil compounds, in order to reduce long term environmental effects. Although bioremediation products have the advantage of stimulating the natural capacity to degrade oil, there are some limitations to be considered. Application as a technique for first emergency actions following an oil spill is not effective, and can therefore be no alternative for dispersion or mechanical removal of floating or freshly stranded oil slicks. Acute toxic effects are related to the short term exposure to unweathered oils. An immediate removal of oil is necessary to reduce the extent of the environmental impact of an oil spill. Physical processes (transport, dilution and evaporation) are determining the initial fate of environmentally released oil. Biodegradation only becomes important as a process of removing oil in the next phase. It is the only effective way to further reduce the concentration of oil that is left in (intertidal) coastal areas. Bioremediation thus reduces the duration of the environmental impact of an oil spill. This is especially important in ecosystems with a low recovery potential (e.g., salt marshes, rocky shores). The experimental evaluation of bioremediation products is mainly based on the capacity to reduce fresh oil and the acute toxicity of the product itself, rather than on the capacity to enhance the further reduction of weathered oil and the toxicological consequences of higher release rates of intermediate metabolites produced during the biotransformation processes

  19. Effects of supplementation of the synbiotic Ecologic

    NARCIS (Netherlands)

    Wilms, E.; Gerritsen, J.; Smidt, H.; Besseling-van der Vaart, I.; Rijkers, G.T.; Garcia Fuentes, A.R.; Masclee, A.A.M.; Troost, F.J.

    2016-01-01

    Background and Aims: Probiotics, prebiotics and synbiotics have been suggested as dietary strategies to improve intestinal barrier function. This study aimed to assess the effect of two weeks synbiotic supplementation on intestinal permeability under basal and stressed conditions. Secondary aims

  20. [Uncertainty characterization approaches for ecological risk assessment of polycyclic aromatic hydrocarbon in Taihu Lake].

    Science.gov (United States)

    Guo, Guang-Hui; Wu, Feng-Chang; He, Hong-Ping; Feng, Cheng-Lian; Zhang, Rui-Qing; Li, Hui-Xian

    2012-04-01

    Probabilistic approaches, such as Monte Carlo Sampling (MCS) and Latin Hypercube Sampling (LHS), and non-probabilistic approaches, such as interval analysis, fuzzy set theory and variance propagation, were used to characterize uncertainties associated with risk assessment of sigma PAH8 in surface water of Taihu Lake. The results from MCS and LHS were represented by probability distributions of hazard quotients of sigma PAH8 in surface waters of Taihu Lake. The probabilistic distribution of hazard quotient were obtained from the results of MCS and LHS based on probabilistic theory, which indicated that the confidence intervals of hazard quotient at 90% confidence level were in the range of 0.000 18-0.89 and 0.000 17-0.92, with the mean of 0.37 and 0.35, respectively. In addition, the probabilities that the hazard quotients from MCS and LHS exceed the threshold of 1 were 9.71% and 9.68%, respectively. The sensitivity analysis suggested the toxicity data contributed the most to the resulting distribution of quotients. The hazard quotient of sigma PAH8 to aquatic organisms ranged from 0.000 17 to 0.99 using interval analysis. The confidence interval was (0.001 5, 0.016 3) at the 90% confidence level calculated using fuzzy set theory, and the confidence interval was (0.000 16, 0.88) at the 90% confidence level based on the variance propagation. These results indicated that the ecological risk of sigma PAH8 to aquatic organisms were low. Each method has its own set of advantages and limitations, which was based on different theory; therefore, the appropriate method should be selected on a case-by-case to quantify the effects of uncertainties on the ecological risk assessment. Approach based on the probabilistic theory was selected as the most appropriate method to assess the risk of sigma PAH8 in surface water of Taihu Lake, which provided an important scientific foundation of risk management and control for organic pollutants in water.

  1. Ecological Effect of Arginine on Oral Microbiota.

    Science.gov (United States)

    Zheng, Xin; He, Jinzhi; Wang, Lin; Zhou, Shuangshuang; Peng, Xian; Huang, Shi; Zheng, Liwei; Cheng, Lei; Hao, Yuqing; Li, Jiyao; Xu, Jian; Xu, Xin; Zhou, Xuedong

    2017-08-03

    Dental caries is closely associated with the microbial dybiosis between acidogenic/aciduric pathogens and alkali-generating commensal bacteria colonized in the oral cavity. Our recent studies have shown that arginine may represent a promising anti-caries agent by modulating microbial composition in an in vitro consortium. However, the effect of arginine on the oral microbiota has yet to be comprehensively delineated in either clinical cohort or in vitro biofilm models that better represent the microbial diversity of oral cavity. Here, by employing a clinical cohort and a saliva-derived biofilm model, we demonstrated that arginine treatment could favorably modulate the oral microbiota of caries-active individuals. Specifically, treatment with arginine-containing dentifrice normalized the oral microbiota of caries-active individuals similar to that of caries-free controls in terms of microbial structure, abundance of typical species, enzymatic activities of glycolysis and alkali-generation related enzymes and their corresponding transcripts. Moreover, we found that combinatory use of arginine with fluoride could better enrich alkali-generating Streptococcus sanguinis and suppress acidogenic/aciduric Streptococcus mutans, and thus significantly retard the demineralizing capability of saliva-derived oral biofilm. Hence, we propose that fluoride and arginine have a potential synergistic effect in maintaining an eco-friendly oral microbial equilibrium in favor of better caries management.

  2. [Effect of ecological civilized homestead construction on schistosomiasis control].

    Science.gov (United States)

    Tang, Meng; Jia, Tie-Wu; Wu, Zi-Song; Mao, Ping; Chen, Lin; Li, Han-Gang; Zhong, Bo; Qiu, Dong-Chuan; Yao, Qin; Hu, You-Ping

    2012-02-01

    To evaluate the effect of Ecological Civilized Homestead Construction on schistosomiasis control. The data of ecological civilized homestead construction and schistosomiasis control were collected and analyzed in Meiwan Village, Shuangqiao Town, Danling County, Sichuan Province from 2004 to 2010. Ecological Civilized Homestead Construction was carried out from 2004 to 2010. Totally 454 bio-gas pools were built. All the farmers used well water. The popularized rates of the household bio-gas pool, sanitary toilet, sewage treatment pool reached 100%. The number of cattle was 4, which decreased by 91.30% compared with that in 2004, and all the cattle were fed in captivity. The schistosome infection rates of populations were 0.26% and 0.30% in 2005 and 2008, respectively, and nobody was infected in other years. The infection rate of cattle was 0 from 2004 to 2010. The awareness rate of knowledge about schistosomiasis control achieved 100% in the population over 6 years old. Most of the farmers could use certain protective measures while they were farming. The effect of ecological civilized homestead construction on schistosomiasis control is remarkable.

  3. Quantifying the dilution effect for models in ecological epidemiology.

    Science.gov (United States)

    Roberts, M G; Heesterbeek, J A P

    2018-03-01

    The dilution effect , where an increase in biodiversity results in a reduction in the prevalence of an infectious disease, has been the subject of speculation and controversy. Conversely, an amplification effect occurs when increased biodiversity is related to an increase in prevalence. We explore the conditions under which these effects arise, using multi species compartmental models that integrate ecological and epidemiological interactions. We introduce three potential metrics for quantifying dilution and amplification, one based on infection prevalence in a focal host species, one based on the size of the infected subpopulation of that species and one based on the basic reproduction number. We introduce our approach in the simplest epidemiological setting with two species, and show that the existence and strength of a dilution effect is influenced strongly by the choices made to describe the system and the metric used to gauge the effect. We show that our method can be generalized to any number of species and to more complicated ecological and epidemiological dynamics. Our method allows a rigorous analysis of ecological systems where dilution effects have been postulated, and contributes to future progress in understanding the phenomenon of dilution in the context of infectious disease dynamics and infection risk. © 2018 The Author(s).

  4. Granulated wood ash to forest soil - Ecological effects

    International Nuclear Information System (INIS)

    Rosen, K.; Eriksson, H.; Clarholm, M.; Lundkvist, H.; Rudebeck, A.

    1993-01-01

    This report describes research concerning ecological effects of wood ash recycling to forest soils. The main part of the minerals in the wood fuels are retained in the ashes after combustion. By returning the ashes back to the cleared forest areas, the mineral losses can be reduced. Adding ashes and limestone is a method to vitalize acidified forest soils and restore the production capacity. 48 refs, 26 figs, 8 tabs

  5. Downstream ecological effects of dams: A geomorphic perspective

    International Nuclear Information System (INIS)

    Ligon, F.K.; Dietrich, W.E.; Trush, W.J.

    1995-01-01

    The damming of a river changes the flow of water, sediment, nutrients, energy, and biota, interrupting and altering most of a river's ecological processes. This article discusses the importance of geomorphological analysis in river conservation and management. To illustrate how subtle geomorphological adjustments may profoundly influence the ecological relationships downstream from dames, three case studies are presented. Then a geomorphically based approach for assessing and possibly mitigating some of the environmental effects of dams by tailoring dam designed and operation is outlined. The cases are as follows: channel simplification and salmon decline on the McKenzie River in Oregon; Channel incision and reduced floodplain inundation on the Oconee river in Georgia; Increased stability of a braided river in New Zealand's south island. 41 refs., 10 figs., 1 tab

  6. Visual search in ecological and non-ecological displays: evidence for a non-monotonic effect of complexity on performance.

    Directory of Open Access Journals (Sweden)

    Philippe Chassy

    Full Text Available Considerable research has been carried out on visual search, with single or multiple targets. However, most studies have used artificial stimuli with low ecological validity. In addition, little is known about the effects of target complexity and expertise in visual search. Here, we investigate visual search in three conditions of complexity (detecting a king, detecting a check, and detecting a checkmate with chess players of two levels of expertise (novices and club players. Results show that the influence of target complexity depends on level of structure of the visual display. Different functional relationships were found between artificial (random chess positions and ecologically valid (game positions stimuli: With artificial, but not with ecologically valid stimuli, a "pop out" effect was present when a target was visually more complex than distractors but could be captured by a memory chunk. This suggests that caution should be exercised when generalising from experiments using artificial stimuli with low ecological validity to real-life stimuli.

  7. Integral statistical eco-indices - effective complementary tool for assessment of ecological state of and ecological risks for water ecosystems

    International Nuclear Information System (INIS)

    Bashamkova, I

    2010-01-01

    Eco-indices are successfully used for assessment of the ecological state and risks of water reservoirs. They allow, already at early stages, to detect negative effects on water ecosystems caused by progressive anthropogenic impacts and widening of the spectrum of pollutants, and to quantitatively evaluate ecological risks and damage for water reservoirs. Implementing these modern tools to water quality assessment is one of the lines to make decisions concerning challenging environmental problems.

  8. Self-DNA inhibitory effects: Underlying mechanisms and ecological implications.

    Science.gov (United States)

    Cartenì, Fabrizio; Bonanomi, Giuliano; Giannino, Francesco; Incerti, Guido; Vincenot, Christian Ernest; Chiusano, Maria Luisa; Mazzoleni, Stefano

    2016-01-01

    DNA is usually known as the molecule that carries the instructions necessary for cell functioning and genetic inheritance. A recent discovery reported a new functional role for extracellular DNA. After fragmentation, either by natural or artificial decomposition, small DNA molecules (between ∼50 and ∼2000 bp) exert a species specific inhibitory effect on individuals of the same species. Evidence shows that such effect occurs for a wide range of organisms, suggesting a general biological process. In this paper we explore the possible molecular mechanisms behind those findings and discuss the ecological implications, specifically those related to plant species coexistence.

  9. Cumulative Effects Assessment: Linking Social, Ecological, and Governance Dimensions

    Directory of Open Access Journals (Sweden)

    Marian Weber

    2012-06-01

    Full Text Available Setting social, economic, and ecological objectives is ultimately a process of social choice informed by science. In this special feature we provide a multidisciplinary framework for the use of cumulative effects assessment in land use planning. Forest ecosystems are facing considerable challenges driven by population growth and increasing demands for resources. In a suite of case studies that span the boreal forest of Western Canada to the interior Atlantic forest of Paraguay we show how transparent and defensible methods for scenario analysis can be applied in data-limited regions and how social dimensions of land use change can be incorporated in these methods, particularly in aboriginal communities that have lived in these ecosystems for generations. The case studies explore how scenario analysis can be used to evaluate various land use options and highlight specific challenges with identifying social and ecological responses, determining thresholds and targets for land use, and integrating local and traditional knowledge in land use planning. Given that land use planning is ultimately a value-laden and often politically charged process we also provide some perspective on various collective and expert-based processes for identifying cumulative impacts and thresholds. The need for good science to inform and be informed by culturally appropriate democratic processes calls for well-planned and multifaceted approaches both to achieve an informed understanding of both residents and governments of the interactive and additive changes caused by development, and to design action agendas to influence such change at the ecological and social level.

  10. Ecological characterization of the lower Everglades, Florida Bay, and the Florida Keys

    Energy Technology Data Exchange (ETDEWEB)

    Schomer, N.S.; Drew, R.D.

    1982-09-01

    A conceptual model of the study area identifies four major ecological zones: (1) terrestrial and freshwater wetlands, (2) estuarine and saltwater wetlands, (3) Florida Bay and mangrove islands, and (4) the Florida Keys. These zones are delineated by differences in basic physical-chemical background factors which in turn promote characteristic ecological communities. The terrestrial and freshwater wetlands support pinelands, sawgrass marshes, wet prairies, sloughs and occasional tree islands. The estuarine and saltwater wetlands support mangrove forests, salt marshes and oscillating salinity systems. Florida Bay exhibits oscillating meso- to hypersaline waters over grassbeds on marine lime mud sediments surrounding deeper lake areas. The exposed tips of the mud banks frequently support mangrove or salt prairie vegetation. The Florida Keys support almost all of the above communities to some small degree but are characterized by extensive offshore coral reefs. The productivity of these communities with regard to fish and wildlife reflects (1) the diversity and type of habitats available to species that are potentially capable of exploiting them, (2) the degree of alteration of these habitats by man and natural forces, and (3) historical, biogeographic and random factors that restrict organisms to specific environments or prohibit them from exploiting a potential habitat.

  11. Ecological land classification and terrestrial environment effects assessment for the Port Hope and Port Granby projects

    International Nuclear Information System (INIS)

    Taylor, M.; Wittkugel, U.; Kleb, H.

    2006-01-01

    The Ecological Land Classification system was developed to provide a standardized methodology for describing plant communities and wildlife habitat in southern Ontario. The method employs a hierarchical classification system. It can be applied at different levels of accuracy, i.e., at regional, sub-regional, and local scales with an increasing differentiation of vegetation communities. The standardization of the approach permits a comparison of vegetation communities from different sites and an evaluation of the rarity of these communities within the province. Further, the approach facilitates the monitoring of changes in terrestrial communities with time. These characteristics make Ecological Land Classification mapping a useful tool for environmental assessment such as the ones undertaken for the Port Hope and Port Granby Long-Term Waste Management Projects, which were conducted pursuant to the Canadian Environmental Assessment Act 1992. In the context of the Environmental Assessment for the Port Hope and Port Granby Projects, an Ecological Land Classification study was undertaken to characterize the terrestrial environment at regional, local and site levels. Vegetation patches (polygons) were delineated on the basis of air photo interpretation. The individual polygons were then visited for detailed inventory and classified to the most detailed level; that is to the vegetation type. Plant communities were then compared with those listed in the Ontario Natural Heritage Information Centre database to determine their rarity and to determine where they rank as Valued Ecosystem Components. Ecological Land Classification mapping results were used in the assessment of effects to Valued Ecosystem Components. A spatial analysis of the digitized vegetation maps showed the geographic extent of habitat losses and impairments due to various project works and activities. Landscape rehabilitation strategies and concepts were subsequently developed based on Ecological Land

  12. Ecological Effects of Grazing in the Northern Tianshan Mountains

    Directory of Open Access Journals (Sweden)

    Xiaotao Huang

    2017-11-01

    Full Text Available Identifying the effects of grazing is critical for the conservation, protection and sustainable use of arid grassland ecosystems. However, research regarding the ecological effects of grazing along mountainous elevation gradients is limited in arid areas, particularly at the regional scale. Using the Biome-BGC grazing model, we explored the effects of grazing on grassland net primary productivity (NPP, evapotranspiration (ET and water use efficiency (WUE from 1979 to 2012 along an elevation gradient in the northern Tianshan Mountains. The NPP, ET and WUE values were generally lower under the grazing scenario than under the ungrazed scenario; the differences between the grazing and ungrazed scenarios showed increasing trends over time; and distinct spatial heterogeneity in these differences was observed. Distinct decreases in NPP and WUE under the grazing scenario mainly occurred in regions with high livestock consumption. The decrease in ET was greater in mountainous areas with high grazing intensity due to decreased transpiration and increased surface runoff. This study contributes to a better understanding of the ecological effects of grazing along an elevation gradient in the northern Tianshan Mountains and provides data to support the scientific management of grassland ecosystems.

  13. Ecological effects from transuranium elements in terrestrial environment

    International Nuclear Information System (INIS)

    Uiker, F.U.

    1985-01-01

    To understand ecological effects from transuranium elements in environment it is necessary to know how their chemical, physical and biological behaviour depends on duration of their being in natural environment. It is necesary to take into account that behaviour of transuranium elements in environment depends on physical and chemical forms of a nuclide as well as on characteristics of ecosystem. Radiation dose of certain tissues plays an essential role here but dose distribution is especially complicated for relatively non-soluble α-irradiators

  14. Assessing ecological effects of radionuclides: data gaps and extrapolation issues

    International Nuclear Information System (INIS)

    Garnier-Laplace, Jacqueline; Gilek, Michael; Sundell-Bergman, Synnoeve; Larsson, Carl-Magnus

    2004-01-01

    By inspection of the FASSET database on radiation effects on non-human biota, one of the major difficulties in the implementation of ecological risk assessments for radioactive pollutants is found to be the lack of data for chronic low-level exposure. A critical review is provided of a number of extrapolation issues that arise in undertaking an ecological risk assessment: acute versus chronic exposure regime; radiation quality including relative biological effectiveness and radiation weighting factors; biological effects from an individual to a population level, including radiosensitivity and lifestyle variations throughout the life cycle; single radionuclide versus multi-contaminants. The specificities of the environmental situations of interest (mainly chronic low-level exposure regimes) emphasise the importance of reproductive parameters governing the demography of the population within a given ecosystem and, as a consequence, the structure and functioning of that ecosystem. As an operational conclusion to keep in mind for any site-specific risk assessment, the present state-of-the-art on extrapolation issues allows us to grade the magnitude of the uncertainties as follows: one species to another > acute to chronic = external to internal = mixture of stressors> individual to population> ecosystem structure to function

  15. Toward effective ecological risk-management of refinery corrective action

    International Nuclear Information System (INIS)

    Metzger, B.H.; Rury, P.M.; Turton, D.; Archibald, B.; Clark, J.; Cura, J.

    1995-01-01

    Cleanup of complex industrial sites, such as refineries, requires risk-based decision tools to ensure that environmentally protective remediation is consistent with current and future land use. However, conventional ecological risk assessment approaches are not well suited for complex industrial sites. Site risk assessments focus on hypothetical chemical risk assuming diverse and undisturbed ecosystems, rather than industrial and disturbed area conditions. In addition, they offer little guidance as to how to make timely and effective risk management decisions. An innovative methodology is proposed to assist industry and regulatory risk managers with rapid EcoRisk reconnaissance and cost-effective remedial decision-making at complex industrial sites. Phase 1 comprises a three-step risk screening of areas of ecological concern at the site, which integrates habitat quality characteristics and potential chemical hazards. It yields an ordering of areas as follows: areas of no significant risk; areas of potentially significant risk; and areas of likely significant risk. A decision rule is then applied to determine appropriate risk management action, including: no action; additional study; and remedial or management action. In Phase 2, additional study is conducted for areas that exhibit potentially significant risk so as to facilitate risk management. This methodology is currently being applied at the 1,300 acre, former Exxon Bayway Refinery in New Jersey

  16. Ecological effects assessment: requirements vs state-of-the-art

    International Nuclear Information System (INIS)

    McKenzie, D.H.; Thomas, J.M.; Eberhardt, L.L.

    1981-05-01

    Concerns for environmental quality, the ecologist's understanding of ecosystems, and the ability to quantitatively sample and evaluate hypotheses have contributed to current requirements and the state-of-the-art in ecological effects assessments in refard to nuclear power plants. The current cooling system approaches, data collection programs, and ecological effects assessments reflect these contributions. Over a decade of experience provides the basis for a timely review and evaluation of current proactice. The magnitude of economic and environmental resources being committed to cooling system alternatives mandates that the decision-making process result in as many optimal choices as possible. In addition, the resources being devoted to environmental data collection and integration provide considerable motivation for providing meaningful input to the decision-making process. It is maintained that the input should be as quantitative and as free from subjective content as is reasonably possible. An alternative viewpoint suggests that the past several decades of experience be considered but a first step, and the current task to be one of designing a second step

  17. Effect of Ecological Restoration on Body Condition of a Predator.

    Directory of Open Access Journals (Sweden)

    Daniel González-Tokman

    Full Text Available Ecological restoration attempts to recover the structure and function of ecosystems that have been degraded by human activities. A crucial test of ecosystem recovery would be to determine whether individuals in restored environments are as healthy as those in conserved environments. However, the impact of restoration on physiology of terrestrial animals has never been tested. Here, we evaluated the effect of two restoration methods on body condition measured as body size, body mass, lipid and muscle content of the spider Nephila clavipes in a tropical dry forest that has suffered chronic disturbance due to cattle grazing. We used experimental plots that had been excluded from disturbance by cattle grazing during eight years. Plots were either planted with native trees (i. e. maximal intervention, or only excluded from disturbance (i. e. minimal intervention, and were compared with control conserved (remnants of original forest and disturbed plots (where cattle is allowed to graze. We predicted (1 better body condition in spiders of conserved and restored sites, compared to disturbed sites, and (2 better body condition in plots with maximal intervention than in plots with minimal intervention. The first prediction was not supported in males or females, and the second prediction was only supported in females: body dry mass was higher in planted than in conserved plots for spiders of both sexes and also higher that in disturbed plots for males, suggesting that plantings are providing more resources. We discuss how different life histories and environmental pressures, such as food availability, parasitism, and competition for resources can explain our contrasting findings in male and female spiders. By studying animal physiology in restoration experiments it is possible to understand the mechanistic basis of ecological and evolutionary processes that determine success of ecological restoration.

  18. Ecological characterization and molecular differentiation of Culex pipiens complex taxa and Culex torrentium in eastern Austria.

    Science.gov (United States)

    Zittra, Carina; Flechl, Eva; Kothmayer, Michael; Vitecek, Simon; Rossiter, Heidemarie; Zechmeister, Thomas; Fuehrer, Hans-Peter

    2016-04-11

    Culex pipiens complex taxa differ in behaviour, ecophysiology and epidemiologic importance. Despite their epidemiologic significance, information on genetic diversity, occurrence and seasonal and spatial distribution patterns of the Cx. pipiens complex is still insufficient. Assessment of seasonal and spatial distribution patterns of Culex pipiens forms and their congener Cx. torrentium is crucial for the understanding of their vector-pathogen dynamics. Female mosquitoes were trapped from April-October 2014 twice a month for a 24-h time period with BG-sentinel traps at 24 sampling sites in eastern Austria, using carbon dioxide as attractant. Ecological forms of Cx. pipiens s.l. and their hybrids were differentiated using the CQ11 locus, and Cx. pipiens forms and their congener Cx. torrentium using the ACE-2 gene. Differential exploitation of ecological niches by Cx. pipiens forms and Cx. torrentium was analysed using likelihood ratio tests. Possible effects of environmental parameters on these taxa were tested using PERMANOVA based on distance matrices and, if significant, were modelled in nMDS ordination space to estimate non-linear relationships. For this study, 1476 Culex spp. were sampled. Culex pipiens f. pipiens representing 87.33 % of the total catch was most abundant, followed by hybrids of both forms (5.62 %), Cx. torrentium (3.79 %) and Cx. pipiens f. molestus (3.25 %). Differences in proportional abundances were found between land cover classes. Ecological parameters affecting seasonal and spatial distribution of these taxa in eastern Austria are precipitation duration, air temperature, sunlight and the interaction term of precipitation amount and the Danube water level, which can be interpreted as a proxy for breeding habitat availability. The Cx. pipiens complex of eastern Austria comprises both ecologically different forms, the mainly ornithophilic form pipiens and the mainly mammalophilic and anthropophilic form molestus. Heterogeneous agricultural

  19. Ecological tax reform - an optimal solution?. Critical remarks on the DIW study ''Economic effects of an ecological tax reform''

    International Nuclear Information System (INIS)

    Boehringer, C.; Fahl, H.; Voss, A.

    1994-01-01

    Through the latest expertise of the German institute for economic research (DIW) regarding an ecological tax reform, the discussion about a tax system considering the shortage of the ressource environment and a deficiency of demand regarding the ressource work is newly provoked. The focus of this article is a critical dealing with the methodical procedure of the German institute for economic reserarch when analyzing the national economic effect of a concretely formulated ecological tax law scenario. When assessing the overall economic consequences of a tax reform, it is recommended to use an analysis instrument, which is farly more consistent compared to the instruments by DIW, and which is more problem adequate through the increased resort to financial knowledge. Based on the obvious weakness of the DIW study, a more extensive comprehension for an ecological tax reform is pleaded for, standing out for an application of taxes based on division of labour and oriented to the objective. (orig./UA) [de

  20. Chemical mixtures and environmental effects: a pilot study to assess ecological exposure and effects in streams

    Science.gov (United States)

    Buxton, Herbert T.; Reilly, Timothy J.; Kuivila, Kathryn; Kolpin, Dana W.; Bradley, Paul M.; Villeneuve, Daniel L.; Mills, Marc A.

    2015-01-01

    Assessment and management of the risks of exposure to complex chemical mixtures in streams are priorities for human and environmental health organizations around the world. The current lack of information on the composition and variability of environmental mixtures and a limited understanding of their combined effects are fundamental obstacles to timely identification and prevention of adverse human and ecological effects of exposure. This report describes the design of a field-based study of the composition and biological activity of chemical mixtures in U.S. stream waters affected by a wide range of human activities and contaminant sources. The study is a collaborative effort by the U.S. Geological Survey and the U.S. Environmental Protection Agency. Scientists sampled 38 streams spanning 24 States and Puerto Rico. Thirty-four of the sites were located in watersheds impacted by multiple contaminant sources, including industrial and municipal wastewater discharges, crop and animal agricultural runoff, urban runoff, and other point and nonpoint contaminant sources. The remaining four sites were minimally development reference watersheds. All samples underwent comprehensive chemical and biological characterization, including sensitive and specific direct analysis for over 700 dissolved organic and inorganic chemicals and field parameters, identification of unknown contaminants (environmental diagnostics), and a variety of bioassays to evaluate biological activity and toxicity.

  1. Genomics meets applied ecology: Characterizing habitat quality for sloths in a tropical agroecosystem.

    Science.gov (United States)

    Fountain, Emily D; Kang, Jung Koo; Tempel, Douglas J; Palsbøll, Per J; Pauli, Jonathan N; Zachariah Peery, M

    2018-01-01

    Understanding how habitat quality in heterogeneous landscapes governs the distribution and fitness of individuals is a fundamental aspect of ecology. While mean individual fitness is generally considered a key to assessing habitat quality, a comprehensive understanding of habitat quality in heterogeneous landscapes requires estimates of dispersal rates among habitat types. The increasing accessibility of genomic approaches, combined with field-based demographic methods, provides novel opportunities for incorporating dispersal estimation into assessments of habitat quality. In this study, we integrated genomic kinship approaches with field-based estimates of fitness components and approximate Bayesian computation (ABC) procedures to estimate habitat-specific dispersal rates and characterize habitat quality in two-toed sloths (Choloepus hoffmanni) occurring in a Costa Rican agricultural ecosystem. Field-based observations indicated that birth and survival rates were similar in a sparsely shaded cacao farm and adjacent cattle pasture-forest mosaic. Sloth density was threefold higher in pasture compared with cacao, whereas home range size and overlap were greater in cacao compared with pasture. Dispersal rates were similar between the two habitats, as estimated using ABC procedures applied to the spatial distribution of pairs of related individuals identified using 3,431 single nucleotide polymorphism and 11 microsatellite locus genotypes. Our results indicate that crops produced under a sparse overstorey can, in some cases, constitute lower-quality habitat than pasture-forest mosaics for sloths, perhaps because of differences in food resources or predator communities. Finally, our study demonstrates that integrating field-based demographic approaches with genomic methods can provide a powerful means for characterizing habitat quality for animal populations occurring in heterogeneous landscapes. © 2017 John Wiley & Sons Ltd.

  2. Molecular ecology of aquatic microbes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    Abstracts of reports are presented from a meeting on Molecular Ecology of Aquatic Microbes. Topics included: opportunities offered to aquatic ecology by molecular biology; the role of aquatic microbes in biogeochemical cycles; characterization of the microbial community; the effect of the environment on aquatic microbes; and the targeting of specific biological processes.

  3. Vulnerability of ecological systems to climatic effects of nuclear war

    International Nuclear Information System (INIS)

    Harwell, M.A.; Hutchinson, T.C.; Cropper, W.P. Jr.; Harwell, C.C.

    1985-01-01

    The authors' analyses are based on a suite of approaches: physiological information, historical analogs, simulation and statistical analyses, and expert judgment. Because of the great complexity of ecosystems across the global landscape and the temporal and spatial complexity of potential nuclear-war induced climatic disturbances, it is not possible uniquely to characterize the effects on ecosystems. A biome approach has been chosen as an appropriate level for generalization of potential effects. Northern Hemisphere temperate terrestrial ecosystems, aquatic ecosystems, tropical ecosystems, and Southern Hemisphere extra-tropical ecosystems are addressed. The ecosystem discussions emphasize effects on the primary producers, in large part because those components are fundamental to the total ecosystem and are often especially vulnerable to the types of perturbations considered here. Estimates of effects on fauna are largely based on those mediated through changes in food supplies. Further study of effects on trophic structures and of indirect effects on species propagated through the complex interactions of ecosystems is required

  4. Assessing Freshwater Ecosystem Service Risk over Ecological, Socioeconomic, and Cultural Gradients: Problem Space Characterization and Methodology

    Science.gov (United States)

    Harmon, T. C.; Villamizar, S. R.; Conde, D.; Rusak, J.; Reid, B.; Astorga, A.; Perillo, G. M.; Piccolo, M. C.; Zilio, M.; London, S.; Velez, M.; Hoyos, N.; Escobar, J.

    2014-12-01

    Freshwater ecosystems and the services they provide are under increasing anthropogenic pressure at local (e.g., irrigation diversions, wastewater discharge) and global scales (e.g., climate change, global trading). The impact depends on an ecosystem's sensitivity, which is determined by its geophysical and ecological settings, and the population and activities in its surrounding watershed. Given the importance of ecosystem services, it is critical that we improve our ability to identify and understand changes in aquatic ecosystems, and translate them to risk of service loss. Furthermore, to inspire changes in human behavior, it is equally critical that we learn to communicate risk, and pose risk mitigation strategies, in a manner acceptable to a broad spectrum of stakeholders. Quantifying the nature and timing of the risk is difficult because (1) we often fail to understand the connection between anthropogenic pressures and the timing and extent of ecosystem changes; and (2) the concept of risk is inherently coupled to human perception, which generally differs with cultural and socio-economic conditions. In this study, we endeavor to assess aquatic ecosystem risks across an international array of six study sites. The challenge is to construct a methodology capable of capturing the marked biogeographical, socioeconomic, and cultural differences among the sites, which include: (1) Muskoka River watershed in humid continental Ontario, Canada; (2) Lower San Joaquin River, an impounded snow-fed river in semi-arid Central California; (3) Ciénaga Grande de Santa Marta, a tropical coastal lagoon in Colombia; (4) Senguer River basin in the semi-arid part of Argentina; (5) Laguna de Rocha watershed in humid subtropical Uruguay; and (6) Palomas Lake complex in oceanic Chilean Patagonia. Results will include a characterization of the experimental gradient over the six sites, an overview of the risk assessment methodology, and preliminary findings for several of the sites.

  5. Linking effects of anthropogenic debris to ecological impacts

    NARCIS (Netherlands)

    Browne, M.A.; Underwood, A.J.; Chapman, M.G.; Williams, R.; Thompson, R.C.; Franeker, van J.A.

    2015-01-01

    Accelerated contamination of habitats with debris has caused increased effort to determine ecological impacts. Strikingly, most work on organisms focuses on sublethal responses to plastic debris. This is controversial because (i) researchers have ignored medical insights about the mechanisms that

  6. Effects of alluvial knickpoint migration on floodplain ecology and geomorphology

    Science.gov (United States)

    Larsen, Annegret; May, Jan-Hendrick

    2016-04-01

    Alluvial knickpoints are well described as erosional mechanism within discontinuous ephemeral streams in the semi-arid SW USA. However, alluvial knickpoints occur globally in a wide range of settings and of climate zones, including temperate SE Australia, subtropical Africa, and tropical Australia. Much attention has been given in the scientific literature to the trigger mechanisms of alluvial knickpoints, which can be summarized as: i) threshold phenomena, ii) climate variability and iii) land-use change, or to a combination of these factors. Recently, studies have focused on the timescale of alluvial knickpoint retreat, and the processes, mechanisms and feedbacks with ecology, geomorphology and hydrology. In this study, we compile data from a global literature review with a case study on a tropical river system in Australia affected by re-occurring, fast migrating (140 myr-1) alluvial knickpoint. We highlight the importance of potential water table declines due to channel incision following knickpoint migration, which in turn leads to the destabilization of river banks, and a shift in floodplain vegetation and fire incursion. We hypothesize that the observed feedbacks might also help to understand the broader impacts of alluvial knickpoint migration in other regions, and might explain the drastic effects of knickpoint migration on land cover and land-use in semi-arid areas.

  7. Ecological and health risk-based characterization of agricultural soils contaminated with polycyclic aromatic hydrocarbons in the vicinity of a chemical plant in China.

    Science.gov (United States)

    Liu, Geng; Niu, Junjie; Guo, Wenjiong; An, Xiangsheng; Zhao, Long

    2016-11-01

    Polycyclic aromatic hydrocarbons (PAHs) from chemical plants can cause serious pollution of surrounding agricultural soils. A comprehensive study of agricultural soils was conducted in the vicinity of a chemical plant in China to characterize the soil PAH concentration, as well as their composition and sources. Human health and a screening-level ecological risk assessment were conducted for PAH contamination in agricultural soils. The results showed that the total concentrations of 16 priority PAHs ranged from 250.49 to 9387.26 ng g(-1), with an average of 2780.42 ng g(-1). High molecular weight PAHs (four to six rings) were the dominant component, accounting for more than 60% of all PAHs. Principal component analysis (PCA) and positive matrix factorization model (PMF) suggested that diesel emissions, coal combustion, coke ovens, and fuel combustion and gasoline emissions were the main sources of PAHs in agricultural soils. The ecological risk assessment results based on the effects range-low (ERL), the effects range-median (ERM), and the ecological screening levels (ESL) indicated that the exposure to ∑PAH16 was >ERL, >ERM, and ≥ERL and ESL at 78.1% of the soil sampling stations, and could induce biological effects in mammals. The Bapeq concentrations posed a potential carcinogenic risk to humans. Further risk management and control of soil PAHs in these agricultural soils is required to ensure the safety of the biocoenosis and human health. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Effect of dissolved humic acid on the Pb bioavailability in soil solution and its consequence on ecological risk.

    Science.gov (United States)

    An, Jinsung; Jho, Eun Hea; Nam, Kyoungphile

    2015-04-09

    Current risk characterization in ecological risk assessment does not consider bioavailability of heavy metals, which highly depends on physicochemical properties of environmental media. This study was set to investigate the effect of humic acid (HA), used as a surrogate of organic matter, on Pb toxicity and the subsequent effect on risk characterization in ecological risk assessment. Pb toxicity was assessed using Microtox(®) in the presence and absence of two different forms of HA, particulate HA (pHA) and dissolved HA (dHA). With increasing contact time, the EC10 values increased (i.e., the toxic effects decreased) and the dissolved Pb concentrations of the filtrates decreased. The high correlation (R = 0.88, p < 0.001) between toxic effects determined using both the mixture and its filtrate as exposure media leads us to conclude that the Pb toxicity highly depends on the soluble fraction. Also, reduced Pb toxicity with increasing dHA concentrations, probably due to formation of Pb-dHA complexes, indicated that Pb toxicity largely comes from free Pb ions. Overall, this study shows the effect of HA on metal toxicity alleviation, and emphasizes the need for incorporating the bioavailable heavy metal concentrations in environmental media as a point of exposure in ecological risk assessment. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Comparing spatially explicit ecological and social values for natural areas to identify effective conservation strategies.

    Science.gov (United States)

    Bryan, Brett Anthony; Raymond, Christopher Mark; Crossman, Neville David; King, Darran

    2011-02-01

    Consideration of the social values people assign to relatively undisturbed native ecosystems is critical for the success of science-based conservation plans. We used an interview process to identify and map social values assigned to 31 ecosystem services provided by natural areas in an agricultural landscape in southern Australia. We then modeled the spatial distribution of 12 components of ecological value commonly used in setting spatial conservation priorities. We used the analytical hierarchy process to weight these components and used multiattribute utility theory to combine them into a single spatial layer of ecological value. Social values assigned to natural areas were negatively correlated with ecological values overall, but were positively correlated with some components of ecological value. In terms of the spatial distribution of values, people valued protected areas, whereas those natural areas underrepresented in the reserve system were of higher ecological value. The habitats of threatened animal species were assigned both high ecological value and high social value. Only small areas were assigned both high ecological value and high social value in the study area, whereas large areas of high ecological value were of low social value, and vice versa. We used the assigned ecological and social values to identify different conservation strategies (e.g., information sharing, community engagement, incentive payments) that may be effective for specific areas. We suggest that consideration of both ecological and social values in selection of conservation strategies can enhance the success of science-based conservation planning. ©2010 Society for Conservation Biology.

  10. Benthic and Landcover Characterization of Salt River Bay National Historical Park and Ecological Preserve

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Habitat maps were created as part of a larger ecological assessment conducted by NOAA's National Ocean Service (NOS), Biogeography Branch, for Salt River Bay...

  11. Genomics meets applied ecology : Characterizing habitat quality for sloths in a tropical agro-ecosystem

    NARCIS (Netherlands)

    Fountain, Emily D; Kang, Jung Koo; Tempel, Douglas J; Palsbøll, Per J; Pauli, Jonathan N; Peery, M Zachariah

    Understanding how habitat quality in heterogeneous landscapes governs the distribution and fitness of individuals is a fundamental aspect of ecology. While mean individual fitness is generally considered a key to assessing habitat quality, a comprehensive understanding of habitat quality in

  12. Coastal zone management in Dubai with reference to ecological characterization along Dubai Creek

    OpenAIRE

    Al Zahed, Khalid

    2008-01-01

    Integrated Coastal Zone Management (ICZM) is a dynamic process in which a coordinated strategy is developed and implemented for the allocation of environmental, socio-cultural, and institutional resources to achieve the conservation and sustainable multiple use of the coastal zone. The present study titled “Coastal Zone Management in Dubai with reference to ecological characterization” is an effort to consider critical water quality and ecological issues in the current and f...

  13. Edge Effects and Ecological Traps: Effects on Shrubland Birds in Missouri

    Science.gov (United States)

    April A. Woodward; Alix D. Fink; Frank R. Thompson III

    2001-01-01

    The effect of habitat edge on avian nesting success has been the focus of considerable debate. We studied relationships between habitat edges, locations of nests, and predation. We tested the ecological trap hypothesis for 5 shrubland bird species in the Missouri Ozarks. We compared habitat selection and daily nest predation rates among 3 distance-to-edge categories....

  14. Extraordinary sex ratios: cultural effects on ecological consequences.

    Directory of Open Access Journals (Sweden)

    Ferenc Molnár

    Full Text Available We model sex-structured population dynamics to analyze pairwise competition between groups differing both genetically and culturally. A sex-ratio allele is expressed in the heterogametic sex only, so that assumptions of Fisher's analysis do not apply. Sex-ratio evolution drives cultural evolution of a group-associated trait governing mortality in the homogametic sex. The two-sex dynamics under resource limitation induces a strong Allee effect that depends on both sex ratio and cultural trait values. We describe the resulting threshold, separating extinction from positive growth, as a function of female and male densities. When initial conditions avoid extinction due to the Allee effect, different sex ratios cannot coexist; in our model, greater female allocation always invades and excludes a lesser allocation. But the culturally transmitted trait interacts with the sex ratio to determine the ecological consequences of successful invasion. The invading female allocation may permit population persistence at self-regulated equilibrium. For this case, the resident culture may be excluded, or may coexist with the invader culture. That is, a single sex-ratio allele in females and a cultural dimorphism in male mortality can persist; a low-mortality resident trait is maintained by father-to-son cultural transmission. Otherwise, the successfully invading female allocation excludes the resident allele and culture and then drives the population to extinction via a shortage of males. Finally, we show that the results obtained under homogeneous mixing hold, with caveats, in a spatially explicit model with local mating and diffusive dispersal in both sexes.

  15. Despite phylogenetic effects, C3-C4 lineages bridge the ecological gap to C4 photosynthesis.

    Science.gov (United States)

    Lundgren, Marjorie R; Christin, Pascal-Antoine

    2017-01-01

    C 4 photosynthesis is a physiological innovation involving several anatomical and biochemical components that emerged recurrently in flowering plants. This complex trait evolved via a series of physiological intermediates, broadly termed 'C 3 -C 4 ', which have been widely studied to understand C 4 origins. While this research program has focused on biochemistry, physiology, and anatomy, the ecology of these intermediates remains largely unexplored. Here, we use global occurrence data and local habitat descriptions to characterize the niches of multiple C 3 -C 4 lineages, as well as their close C 3 and C 4 relatives. While C 3 -C 4 taxa tend to occur in warm climates, their abiotic niches are spread along other dimensions, making it impossible to define a universal C 3 -C 4 niche. Phylogeny-based comparisons suggest that, despite shifts associated with photosynthetic types, the precipitation component of the C 3 -C 4 niche is particularly lineage specific, being highly correlated with that of closely related C 3 and C 4 taxa. Our large-scale analyses suggest that C 3 -C 4 lineages converged toward warm habitats, which may have facilitated the transition to C 4 photosynthesis, effectively bridging the ecological gap between C 3 and C 4 plants. The intermediates retained some precipitation aspects of their C 3 ancestors' habitat, and likely transmitted them to their C 4 descendants, contributing to the diversity among C 4 lineages seen today. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  16. Flow effects on benthic stream invertebrates and ecological processes

    Science.gov (United States)

    Koprivsek, Maja; Brilly, Mitja

    2010-05-01

    Flow is the main abiotic factor in the streams. Flow affects the organisms in many direct and indirect ways. The organisms are directly affected by various hydrodynamic forces and mass transfer processes like drag forces, drift, shear stress, food and gases supply and washing metabolites away. Indirect effects on the organisms are determining and distribution of the particle size and structure of the substrate and determining the morphology of riverbeds. Flow does not affect only on individual organism, but also on many ecological effects. To expose just the most important: dispersal of the organisms, habitat use, resource acquisition, competition and predator-prey interactions. Stream invertebrates are adapted to the various flow conditions in many kinds of way. Some of them are avoiding the high flow with living in a hyporeic zone, while the others are adapted to flow with physical adaptations (the way of feeding, respiration, osmoregulation and resistance to draught), morphological adaptations (dorsoventrally flattened shape of organism, streamlined shape of organism, heterogeneous suckers, silk, claws, swimming hair, bristles and ballast gravel) or with behaviour. As the flow characteristics in a particular stream vary over a broad range of space and time scales, it is necessary to measure accurately the velocity in places where the organisms are present to determine the actual impact of flow on aquatic organisms. By measuring the mean flow at individual vertical in a single cross-section, we cannot get any information about the velocity situation close to the bottom of the riverbed where the stream invertebrates are living. Just measuring the velocity near the bottom is a major problem, as technologies for measuring the velocity and flow of natural watercourses is not adapted to measure so close to the bottom. New researches in the last two decades has shown that the thickness of laminar border layer of stones in the stream is only a few 100 micrometers, what

  17. Environmental transformations and ecological effects of iron-based nanoparticles.

    Science.gov (United States)

    Lei, Cheng; Sun, Yuqing; Tsang, Daniel C W; Lin, Daohui

    2018-01-01

    The increasing application of iron-based nanoparticles (NPs), especially high concentrations of zero-valent iron nanoparticles (nZVI), has raised concerns regarding their environmental behavior and potential ecological effects. In the environment, iron-based NPs undergo physical, chemical, and/or biological transformations as influenced by environmental factors such as pH, ions, dissolved oxygen, natural organic matter (NOM), and biotas. This review presents recent research advances on environmental transformations of iron-based NPs, and articulates their relationships with the observed toxicities. The type and extent of physical, chemical, and biological transformations, including aggregation, oxidation, and bio-reduction, depend on the properties of NPs and the receiving environment. Toxicities of iron-based NPs to bacteria, algae, fish, and plants are increasingly observed, which are evaluated with a particular focus on the underlying mechanisms. The toxicity of iron-based NPs is a function of their properties, tolerance of test organisms, and environmental conditions. Oxidative stress induced by reactive oxygen species is considered as the primary toxic mechanism of iron-based NPs. Factors influencing the toxicity of iron-based NPs are addressed and environmental transformations play a significant role, for example, surface oxidation or coating by NOM generally lowers the toxicity of nZVI. Research gaps and future directions are suggested with an aim to boost concerted research efforts on environmental transformations and toxicity of iron-based NPs, e.g., toxicity studies of transformed NPs in field, expansion of toxicity endpoints, and roles of laden contaminants and surface coating. This review will enhance our understanding of potential risks of iron-based NPs and proper uses of environmentally benign NPs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Characterization of Antibiotics and Antibiotic Resistance Genes on an Ecological Farm System

    Directory of Open Access Journals (Sweden)

    Songhe Zhang

    2015-01-01

    Full Text Available There is a growing concern worldwide about the prevalence of antibiotics and antibiotic resistance genes (ARGs on the farm. In this study, we investigated the distribution of seven antibiotics and ten ARGs in fresh and dried pig feces, in biogas slurry, and in grape-planting soil from an ecological farm. Antibiotics including sulfamethazine, norfloxacin, ofloxacin, tetracycline, oxytetracycline, and chlortetracycline were detected in these samples (except for sulfamethoxazole in dried feces. In general, antibiotics levels in samples were in the sequence: biogas slurry > fresh feces > soil or dried feces. Results of ecological risk assessments revealed that among the seven antibiotics chlortetracycline showed the highest ecological risk. Among the ten ARGs, sulI and tetO were the most prevalent on this ecological farm. There were positive correlations between certain ARGs and the corresponding antibiotics on this ecological farm. Therefore, continuous monitoring of antibiotics and their corresponding ARGs should be conducted in the agroecosystem near the concentrated animal farming operation systems.

  19. Ecological effectiveness of oil spill countermeasures: how clean is clean?

    International Nuclear Information System (INIS)

    Baker, J.M.

    1999-01-01

    This paper with 94 references examines background levels of hydrocarbons and the difficulty of defining clean. Processes and timescales for natural cleaning, and factors affecting natural cleaning timescales are considered. Ecological advantages and disadvantages of clean-up methods are highlighted, and five case histories of oil spills are summarised. The relationships between ecological and socio-economic considerations, and the need for a net environmental benefit analysis which takes into account the advantages and disadvantages of clean-up responses and natural clean-up are discussed. A decision tree for evaluating the requirement for shore clean-up is illustrated. (UK)

  20. Ecological characterization of surface waters in the province of Overijssel, The Netherlands

    NARCIS (Netherlands)

    Verdonschot, P.F.M.

    1990-01-01

    Nowadays many surface waters in The Netherlands tend to become ecologically uniform with the same mediocre quality. A differentiated approach to water management is necessary to stop this process of impoverishment of aquatic ecosystems. In The Netherlands the provincial

  1. Landscape Sources, Ecological Effects, and Management of Nutrients in Lakes of Northeastern USA

    Science.gov (United States)

    Lakes face escalating pressures associated with land cover change and growing human populations. Ecological responses provide context for identifying stressor severity, land use impacts, and management effectiveness. We used EPA National Lakes Assessment data and GIS to develop i...

  2. Aerobic Granular Sludge: Effect of Salt and Insights into Microbial Ecology

    KAUST Repository

    Wang, Zhongwei

    2017-12-01

    Aerobic granular sludge (AGS) technology is a next-generation technology for the biological treatment of wastewater. The advantages of AGS in terms of small footprint, low operation and capital cost and high effluent quality makes it a strong candidate for replacing conventional biological wastewater treatment based on activated sludge (CAS) process, and potentially become the standard for biological wastewater treatment in the future. Saline wastewater is generated from many industrial processes as well as from the use of sea water as a secondary quality water for non-potable use such as toilet flushing to mitigate shortage of fresh water in some coastal cities. Salt is known to inhibit biological wastewater treatment processes in terms of organic and nutrient removal. In the first part of my dissertation, I conducted three lab-scale experiments to 1) evaluate the effect of salt on granulation and nutrient removal in AGS (330 days); 2) develop engineering strategies to mitigate the adverse effect of salt on nutrient removal of AGS (164 days); and 3) compare the effect of salt on the stoichiometry and kinetics of different phosphate accumulating organisms (PAO) clades (PAOI and PAOII) and to determine the effect of potassium and sodium ions on the activities of different PAO clades (225 days). Like other artificial microbial ecosystems (e.g. CAS plant and anaerobic digester), a firm understanding of the microbial ecology of AGS system is essential for process design and optimization. The second part of my dissertation reported the first microbial ecology study of a full-scale AGS plant with the aim of addressing the role of regional (i.e. immigration) versus local factors in shaping the microbial community assembly of different-sized microbial aggregates in AGS. The microbial communities in a full-scale AGS plant in Garmerwolde, The Netherlands, was characterized periodically over 180 days using Illumina sequencing of 16S ribosomal RNA amplicons of the V3-V4

  3. Microbial ecology of artisanal italian cheese: Molecular microbial characterization by culture-independent method

    International Nuclear Information System (INIS)

    Colombo, E.; Scarpellini, M.; Franzatti, L.; Dioguardi, L.

    2009-01-01

    Present study will treat the next topics: ecology of the natural and man made environments and functional diversity of bacteria. The microbial communities in artisanal goat cheeses produced in mountain pastures (typical farms) in Piemonte mountain (North of Italy) change a lot during precessing and ripening time. Moreover cheese microbial ecosystems are different in each small dairy because adventitious microflora can come from the environment and contamination the milk before the cheese making process and the product during manufacture and ripening. (Author)

  4. Microbial ecology of artisanal italian cheese: Molecular microbial characterization by culture-independent method

    Energy Technology Data Exchange (ETDEWEB)

    Colombo, E.; Scarpellini, M.; Franzatti, L.; Dioguardi, L.

    2009-07-01

    Present study will treat the next topics: ecology of the natural and man made environments and functional diversity of bacteria. The microbial communities in artisanal goat cheeses produced in mountain pastures (typical farms) in Piemonte mountain (North of Italy) change a lot during precessing and ripening time. Moreover cheese microbial ecosystems are different in each small dairy because adventitious microflora can come from the environment and contamination the milk before the cheese making process and the product during manufacture and ripening. (Author)

  5. Evolution of asynchronous motor activity in paired muscles: effects of ecology, morphology, and phylogeny.

    Science.gov (United States)

    Gerry, Shannon P; Ramsay, Jason B; Dean, Mason N; Wilga, Cheryl D

    2008-08-01

    Many studies of feeding behavior have implanted electrodes unilaterally (in muscles on only one side of the head) to determine the basic motor patterns of muscles controlling the jaws. However, bilateral implantation has the potential to achieve a more comprehensive understanding of modification of the motor activity that may be occurring between the left and right sides of the head. In particular, complex processing of prey is often characterized by bilaterally asynchronous and even unilateral activation of the jaw musculature. In this study, we bilaterally implant feeding muscles in species from four orders of elasmobranchs (Squaliformes, Orectolobiformes, Carcharhiniformes, Rajoidea) in order to characterize the effects of type of prey, feeding behavior, and phylogeny on the degree of asynchronous muscle activation. Electrodes were implanted in three of the jaw adductors, two divisions of the quadratomandibularis and the preorbitalis, as well as in a cranial elevator in sharks, the epaxialis. The asynchrony of feeding events (measured as the degree to which activity of members of a muscle pair is out of phase) was compared across species for capture versus processing and simple versus complex prey, then interpreted in the contexts of phylogeny, morphology, and ecology to clarify determinants of asynchronous activity. Whereas capture and processing of prey were characterized by statistically similar degrees of asynchrony for data pooled across species, events involving complex prey were more asynchronous than were those involving simple prey. The two trophic generalists, Squalus acanthias and Leucoraja erinacea, modulated the degree of asynchrony according to type of prey, whereas the two behavioral specialists, Chiloscyllium plagiosum and Mustelus canis, activated the cranial muscles synchronously regardless of type of prey. These differences in jaw muscle activity would not have been detected with unilateral implantation. Therefore, we advocate bilateral

  6. The Effect of Learning Cycle Model on Students’ Reducing Ecological Footprints

    Directory of Open Access Journals (Sweden)

    Özgül Keleş

    2011-12-01

    Full Text Available The objective of this study is to investigate effect of ecological footprint education, in which 5E learning cycle model is used, in reducing primary school students’ ecological footprints. The working group of the study is composed of 124 primary school students studying in 4th, 5th, 6th, 7th, 8th classes. In this study, 5E learning model is used in teaching a course in order to increase the participating students’ knowledge about ecological footprints and to calculate ecological footprints. Experimental method is used in this study. In data analysis, the paired samples t-test is used in for relevant samplings. The findings gathered indicate that ecological footprints of the participating students to the study decreased at the end of the study. It is determined that the mean of primary students’ ecological footprints differ from meaningfully according to level of the class and sex. Prospective solution offers are developed by handling the prospective effects of conclusions of the study on sustainable life and environmental education and conclusions’ importance in terms of learning and developing learning programmes with a critical point of view

  7. Wild common bean in the Central Valley of Costa Rica: ecological distribution and molecular characterization

    Directory of Open Access Journals (Sweden)

    Rosa In\\u00E9s Gonz\\u00E1lez Torres

    2004-01-01

    Full Text Available Frijol silvestre en el Valle Central de Costa Rica: distribución ecológica y caracterización molecular. Este trabajo presenta una actualización sobre la distribución de las formas silvestres de fríjol común en Costa Rica, su ecología y su caracterización molecular. Ala fecha 22 poblaciones fueron encontradas en cuatro cuencas alrededor del Valle Central, generalmente en vegetaciones ruderales (frecuentemente bordes de cafetales, con estatuto de conservación variable (desde protegido a amenazado. Su caracterización molecular indica su pertenencia al acervo genético mesoamericano. Varios marcadores indican una variabilidad aumentada en las formas silvestres y permiten inferir la presencia de un fenómeno de flujo genético e introgresión desde materiales cultivados.

  8. Phenotypic characterization and ecological features of Coccidioides spp. from Northeast Brazil.

    Science.gov (United States)

    Cordeiro, R A; Brilhante, R S N; Rocha, M F G; Fechine, M A B; Camara, L M C; Camargo, Z P; Sidrim, J J C

    2006-11-01

    This study extends phenotypic and ecological knowledge of Coccidioides spp., by describing its recovery from soils of Ceará State (Northeast Brazil) and analyzing the in vitro features of the growth of its vegetative phase. Following a human coccidioidomycosis case, Coccidioides spp. strains were isolated from 3 of 14 soil samples collected in an armadillo's burrow. Mycological analysis showed colonies with glabrous, velvety or cottony texture and an increasing quantity of arthroconidia. The overall growth rates of the strains were slower in 8% NaCl medium, maximum growth rate was obtained at 30 degrees C, and their pH tolerance ranged from 4.0 to 11.0. Several carbohydrates and polyalcohol sources could be efficiently metabolized by Coccidioides spp. strains in the mycelial form. Total absence of growth was observed in media supplemented with either L-aspartic acid or L-histidine. Whereas intense growth was found when strains were incubated with any other aminoacid sources studied. Coccidioides spp. strains did not grow in the presence of Tween 60 and Tween 80, but exhibited intense growth in Tween 20. Nicotinic acid and the toxic compounds caffeic acid and phenol could not be metabolized by any strain. All of the strains were positive for urease production and displayed intense growth in media containing cycloheximide concentrations ranging from 0.01 and 0.05%, but did not grow at 0.1 and 0.2%. The present findings confirm the importance of armadillos burrows in the ecology of Coccidioides spp. in Northeast Brazil and indicate that the fungus is a very physiologically versatile organism.

  9. Interaction between Allee effects caused by organism-environment feedback and by other ecological mechanisms.

    Directory of Open Access Journals (Sweden)

    Lijuan Qin

    Full Text Available Understanding Allee effect has crucial importance for ecological conservation and management because it is strongly related to population extinction. Due to various ecological mechanisms accounting for Allee effect, it is necessary to study the influence of multiple Allee effects on the dynamics and persistence of population. We here focus on organism-environment feedback which can incur strong, weak, and fatal Allee effect (AE-by-OEF, and further examine their interaction with the Allee effects caused by other ecological mechanisms (AE-by-OM. The results show that multiple Allee effects largely increase the extinction risk of population either due to the enlargement of Allee threshold or the change of inherent characteristic of Allee effect, and such an increase will be enhanced dramatically with increasing the strength of individual Allee effects. Our simulations explicitly considering spatial structure also demonstrate that local interaction among habitat patches can greatly mitigate such superimposed Allee effects as well as individual Allee effect. This implies that spatially structurized habitat could play an important role in ecological conservation and management.

  10. Interaction between Allee effects caused by organism-environment feedback and by other ecological mechanisms.

    Science.gov (United States)

    Qin, Lijuan; Zhang, Feng; Wang, Wanxiong; Song, Weixin

    2017-01-01

    Understanding Allee effect has crucial importance for ecological conservation and management because it is strongly related to population extinction. Due to various ecological mechanisms accounting for Allee effect, it is necessary to study the influence of multiple Allee effects on the dynamics and persistence of population. We here focus on organism-environment feedback which can incur strong, weak, and fatal Allee effect (AE-by-OEF), and further examine their interaction with the Allee effects caused by other ecological mechanisms (AE-by-OM). The results show that multiple Allee effects largely increase the extinction risk of population either due to the enlargement of Allee threshold or the change of inherent characteristic of Allee effect, and such an increase will be enhanced dramatically with increasing the strength of individual Allee effects. Our simulations explicitly considering spatial structure also demonstrate that local interaction among habitat patches can greatly mitigate such superimposed Allee effects as well as individual Allee effect. This implies that spatially structurized habitat could play an important role in ecological conservation and management.

  11. [Effects of biochar on microbial ecology in agriculture soil: a review].

    Science.gov (United States)

    Ding, Yan-Li; Liu, Jie; Wang, Ying-Ying

    2013-11-01

    Biochar, as a new type of soil amendment, has been obtained considerable attention in the research field of environmental sciences worldwide. The studies on the effects of biochar in improving soil physical and chemical properties started quite earlier, and already covered the field of soil microbial ecology. However, most of the studies considered the soil physical and chemical properties and the microbial ecology separately, with less consideration of their interactions. This paper summarized and analyzed the interrelationships between the changes of soil physical and chemical properties and of soil microbial community after the addition of biochar. Biochar can not only improve soil pH value, strengthen soil water-holding capacity, increase soil organic matter content, but also affect soil microbial community structure, and alter the abundance of soil bacteria and fungi. After the addition of biochar, the soil environment and soil microorganisms are interacted each other, and promote the improvement of soil microbial ecological system together. This review was to provide a novel perspective for the in-depth studies of the effects of biochar on soil microbial ecology, and to promote the researches on the beneficial effects of biochar to the environment from ecological aspect. The methods to improve the effectiveness of biochar application were discussed, and the potential applications of biochar in soil bioremediation were further analyzed.

  12. Effect of ecological factors on the zonation of wetland vegetation

    Directory of Open Access Journals (Sweden)

    Richard Hrivnák

    2011-01-01

    Full Text Available The influence of some ecological factors to aquatic and marsh vegetation was studied during 1998-2000. Three basic vegetation units (Caricetum buekii, Typhetum latifoliae and Ceratophylletum submersi and three transitional communities were defined in the belt transect, which was established along the moisture gradient. The content of available soil nutrients in individual vegetation types differed only in case of the Ceratophyllum submersum community, where a higher magnesium and nitrogen content accumulated due to specific environmental conditions. Water and marsh vegetation is usually characterised by a pronounced spatial and temporal dynamics. In the studied area, its zonation was dependent from the terrain morphology, and both depth and duration of floods. The fluctuation of ground and surface water table during a three-year period caused changes in the occurrence and cover of several species (e.g. Carex buekii, Typha latifolia, aquatic macrophytes. Pronounced changes in the cover of some species occurred even within a single vegetation season due to the long-term sink of water table below the ground surface.

  13. Novel two-tiered approach of ecological risk assessment for pesticide mixtures based on joint effects.

    Science.gov (United States)

    Tian, Dayong; Mao, Haichen; Lv, Huichao; Zheng, Yong; Peng, Conghu; Hou, Shaogang

    2018-02-01

    Ecological risk assessments for mixtures have attracted considerable attention. In this study, 38 pesticides in the real environment were taken as objects and their toxicities to different organisms from three trophic levels were employed to assess the ecological risk of the mixture. The first tier assessment was based on the CA effect and the obtained sum of risk quotients (SRQ species-CA ) were 3.06-9.22. The second tier assessment was based on non-CA effects and the calculated SRQ species-TU are 5.37-9.29 using joint effects (TU sum ) as modified coefficients, which is higher than SRQ species-CA and indicates that ignoring joint effects might run the risk of underestimating the actual impact of pesticide mixtures. Due to the influences of synergistic and antagonistic effects, risk contribution of components to mixture risks based on non-CA effects are different from those based on the CA effect. Moreover, it was found that the top 8 dominating components explained 95.5%-99.8% of mixture risks in this study. The dominating components are similar in the two tiers for a given species. Accordingly, a novel two-tiered approach was proposed to assess the ecological risks of mixtures based on joint effects. This study provides new insights for ecological risk assessments with the consideration of joint effects of components in the pesticide mixtures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Characterization of an artisanal fishery in Argentina using the social-ecological systems framework

    Directory of Open Access Journals (Sweden)

    Silvia London

    2017-03-01

    Full Text Available Institutional Analysis and Development (IAD studies how institutions (the rules of the game of a society determine the performance of a social-economic system. Elinor Ostrom extends the institutional analysis to the collective action for a particular case, the study of the social-ecological systems (SESs. Any group that attempts to manage a common resource (e.g. aquifers, pastures for optimal sustainable production must solve a set of problems in order to create institutions to facilitate collective action. Some evidences show that following a set of design principles in creating institutions can lead to overcome these problems. The aim of the paper is to apply the SES framework to an artisanal fishery community in Argentina in order to: 1 describe the principal features, key variables and relations of the small-scale fishery system; 2 detect the principal drivers of a potential common-management and the leading detractors from the current communal performance; and 3 analyze the possibility that a self-governing for sustainable fishery may appear. Several drivers for potential common-management and some detractors from the current common performance are summarized. Artisanal fishery SES is currently at a bifurcation point. A common historical and cultural root, the presence of leaderships, the relevance of local knowledge, the dependence on the resource to sustainable livelihoods and the threat of big-scale fisheries area have generated incentives to collective-action. But, simultaneously, internal conflicts are the most important barrier for an integrated community-based management. The heterogeneity among actors and the relevant external conditions have resulted in two groups diverging in their self-organization. The work is framed by the project COMET-LA (COmmunity-based Management of Environmental challenges in Latin America; European Commission’s Seventh Framework Programme of Research and Development, which aims to identify sustainable

  15. Quantifying the effects of ecological constraints on trait expression using novel trait-gradient analysis parameters.

    Science.gov (United States)

    Ottaviani, Gianluigi; Tsakalos, James L; Keppel, Gunnar; Mucina, Ladislav

    2018-01-01

    Complex processes related to biotic and abiotic forces can impose limitations to assembly and composition of plant communities. Quantifying the effects of these constraints on plant functional traits across environmental gradients, and among communities, remains challenging. We define ecological constraint ( C i ) as the combined, limiting effect of biotic interactions and environmental filtering on trait expression (i.e., the mean value and range of functional traits). Here, we propose a set of novel parameters to quantify this constraint by extending the trait-gradient analysis (TGA) methodology. The key parameter is ecological constraint, which is dimensionless and can be measured at various scales, for example, on population and community levels. It facilitates comparing the effects of ecological constraints on trait expressions across environmental gradients, as well as within and among communities. We illustrate the implementation of the proposed parameters using the bark thickness of 14 woody species along an aridity gradient on granite outcrops in southwestern Australia. We found a positive correlation between increasing environmental stress and strength of ecological constraint on bark thickness expression. Also, plants from more stressful habitats (shrublands on shallow soils and in sun-exposed locations) displayed higher ecological constraint for bark thickness than plants in more benign habitats (woodlands on deep soils and in sheltered locations). The relative ease of calculation and dimensionless nature of C i allow it to be readily implemented at various scales and make it widely applicable. It therefore has the potential to advance the mechanistic understanding of the ecological processes shaping trait expression. Some future applications of the new parameters could be investigating the patterns of ecological constraints (1) among communities from different regions, (2) on different traits across similar environmental gradients, and (3) for the same

  16. Effect of coffee processing on ecological integrity of river systems in Jimma zone, southwestern Ethiopia

    International Nuclear Information System (INIS)

    Legesse, W.

    2005-01-01

    Jimma Zone in Southwestern Ethiopia is known for its coffee production and the landscape is dotted by a number of coffee processing industries. In order to assess the effect of coffee wastewater on the ecological integrity of the receiving water bodies, a longitudinal study has been initiated in January 2003 and is still in progress. The preliminary results of physicochemical parameters such as BOD (Biochemical Oxygen Demand) indicated that the coffee effluent is characterized by a remarkable polluting potential during the wet coffee-processing season. In general, a corresponding decline of bottom dwelling river fauna has been noted in many sampling locations. If business-as-usual scenario is followed, the economic gains accrued, as a result of coffee export, will be undone due to the ensuing water quality degradation and aquatic ecosystem disturbance. Although further study is required to fix the problem, provision of intervention strategies appear to be mandatory in order to avert quality deterioration of the rivers and streams flowing through the coffee producing region. (author)

  17. Non-linear effects of drought under shade: reconciling physiological and ecological models in plant communities

    NARCIS (Netherlands)

    Holmgren, M.; Gomez-Aparicio, L.; Quero, J.L.; Valladares, F.

    2012-01-01

    The combined effects of shade and drought on plant performance and the implications for species interactions are highly debated in plant ecology. Empirical evidence for positive and negative effects of shade on the performance of plants under dry conditions supports two contrasting theoretical

  18. Cumulative ecological and socioeconomic effects of forest policies in coastal Oregon.

    Science.gov (United States)

    T.A. Spies; K.N. Johnson; K.M. Burnett; J.L. Ohmann; B.C. McComb; G.H. Reeves; P. Bettinger; J.D. Kline; B. Garber-Yonts

    2007-01-01

    Forest biodiversity policies in multiownership landscapes are typically developed in an uncoordinated fashion with little consideration of their interactions or possible unintended cumulative effects. We conducted an assessment of some of the ecological and socioeconomic effects of recently enacted forest management policies in the 2.3-million-ha Coast Range...

  19. Floristic and ecological characterization of habitat types on an inselberg in Minas Gerais, southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Luiza F. A. de Paula

    Full Text Available ABSTRACT Inselbergs are granitic or gneissic rock outcrops, distributed mainly in tropical and subtropical regions. They are considered terrestrial islands because of their strong spatial and ecological isolation, thus harboring a set of distinct plant communities that differ from the surrounding matrix. In Brazil, inselbergs scattered in the Atlantic Forest contain unusually high levels of plant species richness and endemism. This study aimed to inventory species of vascular plants and to describe the main habitat types found on an inselberg located in the state of Minas Gerais, in southeastern Brazil. A total of 89 species of vascular plants were recorded (belonging to 37 families, of which six were new to science. The richest family was Bromeliaceae (10 spp., followed by Cyperaceae (seven spp., Orchidaceae and Poaceae (six spp. each. Life forms were distributed in different proportions between habitats, which suggested distinct microenvironments on the inselberg. In general, habitats under similar environmental stress shared common species and life-form proportions. We argue that floristic inventories are still necessary for the development of conservation strategies and management of the unique vegetation on inselbergs in Brazil.

  20. [Scale effect of Li-Xiang Railway construction impact on landscape pattern and its ecological risk].

    Science.gov (United States)

    Wang, De-zhi; Qiu, Peng-hua; Fang, Yuan-min

    2015-08-01

    As a large corridor project, plateau railway has multiple points and passes various sensitive environments along the railway. The determination of the scope of impact on ecological environment from railway construction is often controversial in ecological impact assessment work. Taking the Tangbu-Jiantang section of Li-Xiang Railway as study object, and using present land use map (1:10000) in 2012 and DEM as data sources, corridor cutting degree index ( CCI) and cumulative effect index of corridor (CCEI) were established by topology, buffer zone and landscape metrics methods. Besides, the ecological risk index used for railway construction was improved. By quantitative analysis of characteristics of the spatio-temporal change of landscape pattern and its evolution style at different spatial scales before and after railway construction, the most appropriate evaluation scale of the railway was obtained. Then the characteristics of the spatio-temporal variation of ecological risk within this scale before and after railway construction were analyzed. The results indicated that the cutting model and degree of railway corridor to various landscape types could be effectively reflected by CCI, and the exposure and harm relations between risk sources and risk receptors of railway can be measured by CCEI. After the railway construction, the railway corridor would cause a great deal of middle cutting effect on the landscape along the railroad, which would influence wood land and grassland landscape most greatly, while would cause less effect of edge cutting and internal cutting. Landscape indices within the 600 m buffer zone demonstrated the most obvious scale effect, therefore, the 600 m zone of the railway was set as the most suitable range of ecological impact assessment. Before railway construction, the low ecological risk level covered the biggest part of the 600 m assessment zone. However, after the railway construction, the ecological risk increased significantly, and

  1. Ecological Effects of Channelization on a Tropical Marine Ecosystem

    African Journals Online (AJOL)

    USER

    important factor limiting usable fish habitat in such systems (Judy et al., 1984; Sheridan et al., 2002). ... affects fish nutrition and reproduction is critical, because the primary effects of ..... To measure the environmental effect of the sedimentation.

  2. Plant selenium hyperaccumulation- Ecological effects and potential implications for selenium cycling and community structure.

    Science.gov (United States)

    Reynolds, R Jason B; Pilon-Smits, Elizabeth A H

    2018-04-25

    Selenium (Se) hyperaccumulation occurs in ~50 plant taxa native to seleniferous soils in Western USA. Hyperaccumulator tissue Se levels, 1000-15,000 mg/kg dry weight, are typically 100 times higher than surrounding vegetation. Relative to other species, hyperaccumulators also transform Se more into organic forms. We review abiotic and biotic factors influencing soil Se distribution and bioavailability, soil being the source of the Se in hyperaccumulators. Next, we summarize the fate of Se in plants, particularly hyperaccumulators. We then extensively review the impact of plant Se accumulation on ecological interactions. Finally, we discuss the potential impact of Se hyperaccumulators on local community composition and Se cycling. Selenium (hyper)accumulation offers ecological advantages: protection from herbivores and pathogens and competitive advantage over other plants. The extreme Se levels in and around hyperaccumulators create a toxic environment for Se-sensitive ecological partners, while offering a niche for Se-resistant partners. Through these dual effects, hyperaccumulators may influence species composition in their local environment, as well as Se cycling. The implied effects of Se hyperaccumulation on community assembly and local Se cycling warrant further investigations into the contribution of hyperaccumulators and general terrestrial vegetation to global Se cycling and may serve as a case study for how trace elements influence ecological processes. Furthermore, understanding ecological implications of plant Se accumulation are vital for safe implementation of biofortification and phytoremediation, technologies increasingly implemented to battle Se deficiency and toxicity. Copyright © 2018. Published by Elsevier B.V.

  3. Ecological aspects od electromagnetic irradiation effects of biological objects

    International Nuclear Information System (INIS)

    Volobuev, A.P.; Donnik, I.M.; Alekseenko, N.N.

    2005-01-01

    General description of electromagnetic field effects on biological objects depending on its frequency properties is stated in the paper. Basic principles of low frequency field effect (10 -1 -0 2 Hz) are detailed. General and specific regularities of biological objects response to a low frequency field on subcell, cell, and system levels were considered taking into account their functional state. (author)

  4. The ecological effectiveness of protected areas: the United Kingdom

    NARCIS (Netherlands)

    Gaston, K.J.; Charman, K.; Jackson, S.F.; Armsworth, P.R.; Bonn, A.; Briers, R.A.; Callaghan, C.S.Q.; Catchpole, R.; Hopkins, J.; Kunin, W.E.; Latham, J.; Opdam, P.F.M.; Stoneman, R.; Stroud, D.A.; Tratt, R.

    2006-01-01

    Given the importance placed on protected areas, determining their effectiveness in representing and maintaining biodiversity is a core issue in conservation biology. Nonetheless, frameworks identifying the breadth of issues associated with this effectiveness, and case studies of how well these are

  5. Indirect effects in community ecology: Their definition, study and importance.

    Science.gov (United States)

    Strauss, S Y

    1991-07-01

    The diversity of indirect interactions that can occur within communities is large. Recent research on indirect interactions is scattered in the literature under numerous labels. The definition of indirect effects is an important aspect of their study, and clarifies some of the subtle differences among indirect effects found in natural communities. Choosing which species to study, how to manipulate species and for what duration, which attributes to measure and, finally, which analytical techniques to use are all problems facing the community ecologist. Ultimately, we are striving for the best means of determining the relative importance of direct and indirect effects in structuring communities. Copyright © 1991. Published by Elsevier Ltd.

  6. Characterization of an ecological binder for mortars obtained from recycling of ladle furnace slag

    International Nuclear Information System (INIS)

    Marinho, A.B.; Santos, C.M.; Fontes, W.C.; Matias, A.C.P.; Brigolini, G.J.; Peixoto, R.A.F.; Carvalho, J.F.

    2016-01-01

    A sustainable binder obtained from recycling of a ladle furnace slag from Piracicaba, Sao Paulo, was produced in Laboratory of Construction Materials of Federal University of Ouro Preto (UFOP). A characterization work was performed and the results are presented. The physical, chemical and mineralogical properties was obtained using, among others, the following techniques: X-ray fluorescence (XRF), X-ray diffraction (XRD) with Rietveld refining method, optical microscopy and Scanning electronic microscopy (SEM) with energy dispersive spectroscopy (EDS). The chemical analysis showed predominance of CaO and SiO_3; the mineralogical analysis pointed the predominant presence of calcium-olivine, merwinite and pyroxene and; the images showed predominance of angulous and elongated grains. According to results, the material was classified as a hydraulic binder, with characteristics comparable to hydraulic limes. (author)

  7. CROSERF: Toward a standardization of oil spill cleanup agent ecological effects research

    International Nuclear Information System (INIS)

    Singer, M.; Tjeerdema, R.; Aurand, D.; Clark, J.; Sergy, G.

    1995-01-01

    The establishment in 1994 of the Chemical Response to Oil Spills Ecological Effects Research Forum (CROSERF) for the development of standardization of protocols used in ecological research of oil spills and remediation efforts was described. Background and the need for such an organization was discussed. Discussions at the two meetings of the forum to date (generation of scientific data for decision making in August 1994 at the University of California at Santa Cruz, and toxicity testing of the water-accommodated fraction of the oil in March 1995 at the Louisiana Oil Spill Coordinator's Office in Baton Rouge) were summarized. A list of the organizations represented at the meetings was given. 5 refs

  8. Effects of salinity and water temperature on the ecological performance of Zostera marina

    DEFF Research Database (Denmark)

    Nejrup, Lars Brammer; Pedersen, Morten Foldager

    2008-01-01

    We tested the effects of salinity and water temperature on the ecological performance of eelgrass (Zostera marina L.) in culture-experiments to identify levels that could potentially limit survival and growth and, thus, the spatial distribution of eelgrass in temperate estuaries. The experiments ...

  9. The Effects of Poverty on Children's Socioemotional Development: An Ecological Systems Analysis.

    Science.gov (United States)

    Eamon, Mary Keegan

    2001-01-01

    Bronfenbrenner's process-person-context-time model is used to examine theories that explain adverse effects of economic deprivation on children's socioemotional development. Processes of not only the family, but also those of the peer group and school, and in other levels of the ecological environment may also explain the relation between economic…

  10. The Effect of Environmental Education on the Ecological Literacy of First-Year College Students

    Science.gov (United States)

    Bruyere, Brett L.

    2008-01-01

    This article assesses the viability of a value-attitude-behavior hierarchy within the context of four environmentally responsible behavior types of first-year college students. The research also studies the effect of knowledge on attitude and behavior, and discusses the implications of the results for understanding the ecological literacy of…

  11. Effects of Conceptual Change Text Based Instruction on Ecology, Attitudes toward Biology and Environment

    Science.gov (United States)

    Çetin, Gülcan; Ertepinar, Hamide; Geban, Ömer

    2015-01-01

    The purpose of this study is to investigate the effects of the conceptual change text based instruction on ninth grade students' understanding of ecological concepts, and attitudes toward biology and environment. Participants were 82 ninth grade students in a public high school in the Northwestern Turkey. A treatment was employed over a five-week…

  12. FORUM: Effective management of ecological resilience – are we there yet?

    Science.gov (United States)

    Spears, Bryan M.; Ives, Stephen C.; Angeler, David G.; Allen, Craig R.; Birk, Sebastian; Carvalho, Laurence; Cavers, Stephen; Daunt, Francis; Morton, R. Daniel; Pocock, Michael J. O.; Rhodes, Glenn; Thackeray, Stephen J.

    2015-01-01

    Ecological resilience is developing into a credible paradigm for policy development and environmental management for preserving natural capital in a rapidly changing world. However, resilience emerges from complex interactions, limiting the translation of theory into practice.Main limitations include the following: (i) difficulty in quantification and detection of changes in ecological resilience, (ii) a lack of empirical evidence to support preventative or proactive management and (iii) difficulties in managing processes operating across socio-ecological systems that vary in space and time.We highlight recent research with the potential to address these limitations including new and/or improved indicators of resilience and tools to assess scale as a driver of resilience.Synthesis and applications. Effective resilience-based management must be adaptive in nature. To support this, we propose an operational model using resilience-based iterative management actions operating across scales.

  13. [Characterization of High Andean forest edges and implications for their ecological restoration (Colombia)].

    Science.gov (United States)

    Montenegro, Alba Lucía; Vargas Ríos, Orlando

    2008-09-01

    The growth of a forest patch through colonization of the adjacent matrix is mostly determined by the particular characteristics of the edge zone. Knowing how these characteristics are related to a specific edge type and how they influence the regeneration process, is important for High Andean forest edges restoration. This study aimed to characterize three types of High Andean forest edge in Cogua Forest Reserve (Colombia): 1) edge of Chusquea scandens, 2) "paramizado", and 3) old edge, characterized for being in a later successional state. Two forest patches were chosen for each edge type and 13 criteria were analyzed; these were of topographic order, micro-environmental order, vegetation structure and species composition. In each patch the vegetation was evaluated by means of two 60 m transects perpendicular to the edge and along the matrix-edge-interior of the forest gradient. All woody plant species were identified and counted to determine their abundance. Environmental variables (air temperature, relative humidity, wind speed, and light radiation) were measured in one of the transects. Three of the 13 criteria were of little importance in shaping the type of edge habitat (slope, patch shape and area). The others were closely related with the micro-environmental conditions and in turn with the vegetation structure and composition; this relationship confers particular characteristics to each edge type. The microclimate and floristic edge limits coincided; edges extend between 10 and 20 m into the forest depending on the edge type. The paramizado edge has the smallest environmental self-regulation capacity and is more exposed to fluctuations of the studied variables, because of its greatest exposition to the wind action and loss of the tallest trees (between 10 and 15 m) which regulate the understorey microclimate. This low environmental buffer capacity prevents the establishing of mature forest species (for example, Schefflera sp. and Oreopanax bogotensis

  14. Radio-ecological characterization and radiological assessment in support of regulatory supervision of legacy sites in northwest Russia

    International Nuclear Information System (INIS)

    Sneve, M.K.; Kiselev, M.; Shandala, N.K.

    2014-01-01

    The Norwegian Radiation Protection Authority has been implementing a regulatory cooperation program in the Russian Federation for over 10 years, as part of the Norwegian government's Plan of Action for enhancing nuclear and radiation safety in northwest Russia. The overall long-term objective has been the enhancement of safety culture and includes a special focus on regulatory supervision of nuclear legacy sites. The initial project outputs included appropriate regulatory threat assessments, to determine the hazardous situations and activities which are most in need of enhanced regulatory supervision. In turn, this has led to the development of new and updated norms and standards, and related regulatory procedures, necessary to address the often abnormal conditions at legacy sites. This paper presents the experience gained within the above program with regard to radio-ecological characterization of Sites of Temporary Storage for spent nuclear fuel and radioactive waste at Andreeva Bay and Gremikha in the Kola Peninsula in northwest Russia. Such characterization is necessary to support assessments of the current radiological situation and to support prospective assessments of its evolution. Both types of assessments contribute to regulatory supervision of the sites. Accordingly, they include assessments to support development of regulatory standards and guidance concerning: control of radiation exposures to workers during remediation operations; emergency preparedness and response; planned radionuclide releases to the environment; development of site restoration plans, and waste treatment and disposal. Examples of characterization work are presented which relate to terrestrial and marine environments at Andreeva Bay. The use of this data in assessments is illustrated by means of the visualization and assessment tool (DATAMAP) developed as part of the regulatory cooperation program, specifically to help control radiation exposure in operations and to support

  15. Deep sequencing and ecological characterization of gut microbial communities of diverse bumble bee species.

    Directory of Open Access Journals (Sweden)

    Haw Chuan Lim

    Full Text Available Gut bacterial communities of bumble bees are correlated with defense against pathogens. Further understanding this host-microbe association is vitally important as bumble bees are currently experiencing global population declines, potentially due in part to emergent diseases. In this study, we used pyrosequencing and community fingerprinting (ARISA to characterize the gut microbial communities of nine bumble species from across the Bombus phylogeny. Overall, we delimited 74 bacterial taxa (operational taxonomic units or OTUs belonging to Betaproteobacteria, Gammaproteobacteria, Bacilli, Actinobacteria, Flavobacteria and Alphaproteobacteria. Each bacterial community was taxonomically simple, containing an average of 1.9 common (relative abundance per sample > 5% bacterial OTUs. The most abundant and prevalent (occurring in 92% of the samples bacterial OTU, based on 16S rRNA sequences, closely matched that of the previously described Betaproteobacteria species Snodgrassella alvi. Bacteria that were first described in bee-related external environments dominated a number of gut bacterial communities, suggesting that they are not strictly dependent on the internal gut environment. The ARISA data showed a correlation between bacterial community structures and the geographic locations where the bees were sampled, suggesting that at least a subset of the bacterial species may be transmitted environmentally. Using light and fluorescent microscopy, we demonstrated that the gut bacteria form a biofilm on the internal epithelial surface of the ileum, corroborating results obtained from Apis mellifera.

  16. [Effects of land use structure change on regional ecological health--taking Shapingba County as an example].

    Science.gov (United States)

    Wang, Cheng; Wei, Chaofu; Gao, Ming; Luo, Guanglian; Jiang, Wei

    2005-12-01

    Land resource is the carrier for the exchange of matter, energy and information flows, while the change velocity and the intensity of land use has strong effects on the ecological processes such as matter circulation, energy flow, and biologic diversity. Land use structure change will alter the type, area, and spatial distribution of ecosystem, and in the meantime, result in the changes of regional ecological health. Employing the principles and methods of landscape ecology, and through endowing relative ecological value to land use type, this paper analyzed the charaeteristics of recent 10 years land use change in Shapingba County of Chongqing, and discussed the effects of land use change on regional ecological health, aimed to provide scientific references for land use planning and sustainable land resource utilization. The results indicated that transformation often occurred among different land use types, and the land use structure in each transformation phase differed quite obviously. Under different land use structure, there was a great disparity in relative ecological value of sub-ecosystems, which played various roles in regional ecological health. In general, the regional relative ecological value embodied both increase and decrease. In the future, the relative ecological value of sub-ecosystem would represent three tendencies, i.e., increase first and decrease then, continuous decrease, and continuous increase. The situation of regional ecological health would gradually become better.

  17. Ecological characterization of toxic phytoplankton species (Dinophysis spp., Dinophyceae) in Slovenian mariculture areas (Gulf of Trieste, Adriatic Sea) and the implications for monitoring

    International Nuclear Information System (INIS)

    France, Janja . E-mail france@mbss.org; Mozetic, Patricija

    2006-01-01

    Diarrhetic shellfish poisoning (DSP) events are often registered in Slovenian mariculture areas (Gulf of Trieste, Adriatic Sea) and are related to the occurrence of Dinophysis spp. The annual dynamic of this genus and succession of the most important species were studied at two shellfish farms during monitoring fieldwork in the period 1995-2003. Results indicate that the Dinophysis genus maintains a relatively stable inter-annual dynamic at both sites. The Dinophysis community is characterized by two surface maxima in June and September, while in the middle layer only the autumn peak is pronounced (peak median 92 cells l -1 ). Occasional abundance maxima of around 2000 cells l -1 in the surface layer indicate that potential outbursts of toxic species are less predictable than their seasonal dynamic. On the basis of multivariate analysis, Dinophysis sacculus was characterized as a typical late spring-early summer species, and Dinophysis caudata and Dinophysis fortii as autumn species. Correlation analysis revealed the influence of stratified conditions only on the most abundant species, D. sacculus. Ecological characteristics of the species were combined with shellfish safety requirements towards a more effective monitoring

  18. Interactions between Genetic and Ecological Effects on the Evolution of Life Cycles.

    Science.gov (United States)

    Rescan, Marie; Lenormand, Thomas; Roze, Denis

    2016-01-01

    Sexual reproduction leads to an alternation between haploid and diploid phases, whose relative length varies widely across taxa. Previous genetical models showed that diploid or haploid life cycles may be favored, depending on dominance interactions and on effective recombination rates. By contrast, niche differentiation between haploids and diploids may favor biphasic life cycles, in which development occurs in both phases. In this article, we explore the interplay between genetical and ecological factors, assuming that deleterious mutations affect the competitivity of individuals within their ecological niche and allowing different effects of mutations in haploids and diploids (including antagonistic selection). We show that selection on a modifier gene affecting the relative length of both phases can be decomposed into a direct selection term favoring the phase with the highest mean fitness (due to either ecological differences or differential effects of mutations) and an indirect selection term favoring the phase in which selection is more efficient. When deleterious alleles occur at many loci and in the presence of ecological differentiation between haploids and diploids, evolutionary branching often occurs and leads to the stable coexistence of alleles coding for haploid and diploid cycles, while temporal variations in niche sizes may stabilize biphasic cycles.

  19. Additional potential effects of nuclear war on ecological systems

    International Nuclear Information System (INIS)

    Hutchinson, T.C.; Harwell, M.A.; Cropper, W.P. Jr.; Grover, H.D.

    1985-01-01

    The authors summarize biological and ecosystem responses to enhanced UV-B, air pollutants, radiation, and fire. The concentrations and biological responses associated with these perturbations are based on current experience and experimentation. Additional research is needed to quantify probable post-nuclear war exposures and potential responses. A summary is provided of all the potential effects of nuclear war on the variety of the Earth's ecosystems, including perturbations from climatic alterations, radiation, pollutants, and UV-B

  20. Oil spill studies: A review of ecological effects

    Science.gov (United States)

    Teal, John M.; Howarth, Robert W.

    1984-01-01

    We reviewed seven particularly well known and/or studied oil spills that have occurred since the National Academy of Sciences 1975 report, “Petroleum in the Marine Environment” or that occurred prior to that report but about which significant new information has since been acquired. The spills studied were from the barge Florida, and tankers Arrow, Argo Merchant, Amoco Cadiz, and Tsesis and blowouts from the Bravo and Ixtoc I platforms. These “best” studies yield only limited insight into effects because they lack controls and have a high degree of natural variability. The Tsesis, Florida, and Amoco Cadiz cases are exceptional since they occurred in areas of ongoing research programs and had nearby areas suitable for controls. Oil spills have produced measurable effects on ecosystems that have not been readily predictable from laboratory studies on isolated organisms. However, ecosystemlevel interactions are poorly understood even without the complications resulting from effects of pollution. These generalizations emerge: oil regularly reaches sediments after a spill; oil in anoxic sediments is persistent; oil regularly contaminates Zooplankton and benthic invertebrates; fish are also contaminated, but to a lesser extent; oil contamination decreases the abundance and diversity of benthic communities.

  1. Characterization of potential fire regimes: applying landscape ecology to fire management in Mexico

    Science.gov (United States)

    Jardel, E.; Alvarado, E.; Perez-Salicrup, D.; Morfín-Rios, J.

    2013-05-01

    Knowledge and understanding of fire regimes is fundamental to design sound fire management practices. The high ecosystem diversity of Mexico offers a great challenge to characterize the fire regime variation at the landscape level. A conceptual model was developed considering the main factors controlling fire regimes: climate and vegetation cover. We classified landscape units combining bioclimatic zones from the Holdridge life-zone system and actual vegetation cover. Since bioclimatic conditions control primary productivity and biomass accumulation (potential fuel), each landscape unit was considered as a fuel bed with a particular fire intensity and behavior potential. Climate is also a determinant factor of post-fire recovery rates of fuel beds, and climate seasonality (length of the dry and wet seasons) influences fire probability (available fuel and ignition efficiency). These two factors influence potential fire frequency. Potential fire severity can be inferred from fire frequency, fire intensity and behavior, and vegetation composition and structure. Based in the conceptual model, an exhaustive literature review and expert opinion, we developed rules to assign a potential fire regime (PFR) defined by frequency, intensity and severity (i.e. fire regime) to each bioclimatic-vegetation landscape unit. Three groups and eight types of potential fire regimes were identified. In Group A are fire-prone ecosystems with frequent low severity surface fires in grasslands (PFR type I) or forests with long dry season (II) and infrequent high-severity fires in chaparral (III), wet temperate forests (IV, fire restricted by humidity), and dry temperate forests (V, fire restricted by fuel recovery rate). Group B includes fire-reluctant ecosystems with very infrequent or occasional mixed severity surface fires limited by moisture in tropical rain forests (VI) or fuel availability in seasonally dry tropical forests (VII). Group C and PFR VIII include fire-free environments

  2. Ecological effects occurring outside the land application sites

    International Nuclear Information System (INIS)

    McBride, T.P.

    1992-01-01

    At Nabarlek the impacts of remobilised salts from the irrigation areas are observable in Gadjerigamundah Creek where the waters contain additional solutes, including ammonium (1991 average 3.6 mg N/L), sulphate (1991 average 73 mg/L and nitrate (1991 average 66 mg N/L) and have low pH (1991 observed minimum 4.4). The existence of biological impacts in Gadjerigamundah Creek is suggested by changes in fish community structure observed in a multi-year study commissioned by Queensland Mines Pty. Ltd. Because of high dilution, mining attributable effects on Cooper Creek water chemistry are scarcely detectable and effects on its biota are not expected to be observable. At Ranger increased concentrations of magnesium (up to 4.3 mg/L), sulphate (up to 17 mg/L) and uranium (up to 1.7 μg/L) have been observed in Magela Creek at site GS8210009 during the 1990-91 Wet season and salts derived from irrigation possibly contributed to these values. However the monitoring data presently available do not allow the effects of irrigation-derived solutes on Magela Creek water chemistry to be separated from those of solutes contained in released Retention Pond 1 (RP1) and Retention Pond 4 (RP4) waters. A model developed by OSS for predicting transport of solutes from the irrigation area to Magela Creek suggests that the irrigation area has the capacity to be significant source of additional solutes. Although no monitoring has taken place in Magela Creek to detect biological impacts in Magela Creek caused specifically by irrigation, sensitive procedures used to monitor waste water releases have not detected any impacts on biota. 3 refs., 4 tabs., 9 figs

  3. Ecological effects of feral biofuel crops in constructed oak ...

    Science.gov (United States)

    The effects of elevated temperatures and drought on constructed oak savannahs were studied to determine the interactive effects of potentially invasive feral biofuel species and climate change on native grassland communities. A total of 12 sunlit mesocosm were used. Each mesocosm held three tubs. One had six native plant species; one had five native species with the annual crop Sorghum bicolor and one had five native species along with the weedy perennial Sorghum halepense. The experimental treatments were ambient (control), elevated temperature, drought, or a combination of elevated temperature and drought. Total aboveground biomass of the community was greatest in the control and drought treatments, lowest with elevated temperature + drought, and intermediate in high temperature treatments (Pbacterial biomass. Active bacterial biomass was lowest in the drought and elevated temperature and drought treatments (P<0.05). Active soil fungal biomass was highest in the tubs containing S. bicolor. Percent total carbon in the soil increased between 2010 and 2011 (P=0.0054); it was lowest in the elevated temperature and drought mesocosms (P<0.05). Longer term studi

  4. Radio-ecological characterization and radiological assessment in support of regulatory supervision of legacy sites in northwest Russia.

    Science.gov (United States)

    Sneve, M K; Kiselev, M; Shandala, N K

    2014-05-01

    The Norwegian Radiation Protection Authority has been implementing a regulatory cooperation program in the Russian Federation for over 10 years, as part of the Norwegian government's Plan of Action for enhancing nuclear and radiation safety in northwest Russia. The overall long-term objective has been the enhancement of safety culture and includes a special focus on regulatory supervision of nuclear legacy sites. The initial project outputs included appropriate regulatory threat assessments, to determine the hazardous situations and activities which are most in need of enhanced regulatory supervision. In turn, this has led to the development of new and updated norms and standards, and related regulatory procedures, necessary to address the often abnormal conditions at legacy sites. This paper presents the experience gained within the above program with regard to radio-ecological characterization of Sites of Temporary Storage for spent nuclear fuel and radioactive waste at Andreeva Bay and Gremikha in the Kola Peninsula in northwest Russia. Such characterization is necessary to support assessments of the current radiological situation and to support prospective assessments of its evolution. Both types of assessments contribute to regulatory supervision of the sites. Accordingly, they include assessments to support development of regulatory standards and guidance concerning: control of radiation exposures to workers during remediation operations; emergency preparedness and response; planned radionuclide releases to the environment; development of site restoration plans, and waste treatment and disposal. Examples of characterization work are presented which relate to terrestrial and marine environments at Andreeva Bay. The use of this data in assessments is illustrated by means of the visualization and assessment tool (DATAMAP) developed as part of the regulatory cooperation program, specifically to help control radiation exposure in operations and to support

  5. The special effects of hypnosis and hypnotherapy: A contribution to an ecological model of therapeutic change.

    Science.gov (United States)

    Mende, Matthias

    2006-04-01

    There is ample evidence that hypnosis enhances the effectiveness of psychotherapy and produces some astounding effects of its own. In this paper, the effective components and principles of hypnosis and hypnotherapy are analyzed. The "special" hypnotic and hypnotherapeutic effects are linked to the fact that the ecological requirements of therapeutic change are taken into account implicitly and/or explicitly when working with hypnotic trances in a therapeutic setting. The hypnotic situation is described--theoretically and in case examples--as a therapeutic modality that gratifies and aligns the basic emotional needs to feel autonomous, related, competent, and oriented. It is shown how the hypnotic relationship can help promote a sound ecological balance between these needs--a balance that is deemed to be a necessary prerequisite for salutogenesis. Practical implications for planning hypnotherapeutic interventions are discussed.

  6. Indirect Effects of Global Change: From Physiological and Behavioral Mechanisms to Ecological Consequences.

    Science.gov (United States)

    Gunderson, Alex R; Tsukimura, Brian; Stillman, Jonathon H

    2017-07-01

    A major focus of current ecological research is to understand how global change makes species vulnerable to extirpation. To date, mechanistic ecophysiological analyses of global change vulnerability have focused primarily on the direct effects of changing abiotic conditions on whole-organism physiological traits, such as metabolic rate, locomotor performance, cardiac function, and critical thermal limits. However, species do not live in isolation within their physical environments, and direct effects of climate change are likely to be compounded by indirect effects that result from altered interactions with other species, such as competitors and predators. The Society for Integrative and Comparative Biology 2017 Symposium "Indirect Effects of Global Change: From Physiological and Behavioral Mechanisms to Ecological Consequences" was designed to synthesize multiple approaches to investigating the indirect effects of global change by bringing together researchers that study the indirect effects of global change from multiple perspectives across habitat, type of anthropogenic change, and level of biological organization. Our goal in bringing together researchers from different backgrounds was to foster cross-disciplinary insights into the mechanistic bases and higher-order ecological consequences of indirect effects of global change, and to promote collaboration among fields. © The Author 2017. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  7. Ecological effects on arbovirus-mosquito cycles of transmission.

    Science.gov (United States)

    Tabachnick, Walter J

    2016-12-01

    Mosquitoes transmit many viruses to a variety of hosts. Cycles of mosquito borne arbovirus transmission are the result of complex interactions between the mosquito, the arbovirus and the host that are influenced by genetic variations in a variety of traits in each that are all influenced by many environmental factors. R 0 , the basic reproduction number or mean number of individuals infected from a single infected individual, is a measure of mosquito borne arbovirus transmission. Understanding the causes for the distribution of R 0 in any transmission cycle is a daunting challenge due to the lack of information on the genetic and environmental variances that influence R 0 . Information about the major factors influencing R 0 for specific transmission cycles is essential to develop efficient and effective strategies to reduce transmission in different cycles and locations. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Effects of season on ecological processes in extensive earthen tilapia ponds in Southeastern Brazil.

    Science.gov (United States)

    Favaro, E G P; Sipaúba-Tavares, L H; Milstein, A

    2015-11-01

    In Southeastern Brazil tilapia culture is conducted in extensive and semi-intensive flow-through earthen ponds, being water availability and flow management different in the rainy and dry seasons. In this region lettuce wastes are a potential cheap input for tilapia culture. This study examined the ecological processes developing during the rainy and dry seasons in three extensive flow-through earthen tilapia ponds fertilized with lettuce wastes. Water quality, plankton and sediment parameters were sampled monthly during a year. Factor analysis was used to identify the ecological processes occurring within the ponds and to construct a conceptual graphic model of the pond ecosystem functioning during the rainy and dry seasons. Processes related to nitrogen cycling presented differences between both seasons while processes related to phosphorus cycling did not. Ecological differences among ponds were due to effects of wind protection by surrounding vegetation, organic loading entering, tilapia density and its grazing pressure on zooplankton. Differences in tilapia growth among ponds were related to stocking density and ecological process affecting tilapia food availability and intraspecific competition. Lettuce wastes addition into the ponds did not produce negative effects, thus this practice may be considered a disposal option and a low-cost input source for tilapia, at least at the amounts applied in this study.

  9. Assessment of a subtropical riparian forest focusing on botanical, meteorological, ecological characterization and chemical analysis of rainwater

    Directory of Open Access Journals (Sweden)

    Vanessa Graeff

    2018-05-01

    Full Text Available Riparian forests are heterogeneous environments, in which epiphytes find ideal conditions to develop. These plants absorb the necessary nutrients for survival from the atmosphere, and their occurrence and distribution can be influenced by the quality and quantity of precipitation. The objective of this research was to perform an integrated analysis of botanical, meteorological and chemical precipitation parameters so as to compare them in fragments of the riparian forest in the lower (São Leopoldo-SL and upper (Caraá-CA stretches of the Rio dos Sinos Hydrographic Basin (RSHB, RS, Brazil. Rainwater was chemically analyzed, the community structure of epiphytic ferns was surveyed and the ecological characterization was evaluated through the Rapid Habitat Assessment Protocol (RHAP. The results showed that the chemical composition of rainwater is influenced by the environment of each area. In the upper stretch (CA, for instance, the main contribution is that of marine ions, while in the lower stretch (SL, the most impacting aspects are urbanization and industrialization. Similarly, the results depict a reduction of richness and a simplification of the community structure of epiphytic ferns and their environmental quality according to the RHAP categories, towards the base level of the RSHB. The integrated analysis, in which different methods were applied, proved to be an efficient tool to evaluate environmental quality. This analysis considers that a greater number of biotic and abiotic variables may be applied in different scenarios.

  10. The effect of mining on landscape ecological systems and land reclamation

    International Nuclear Information System (INIS)

    Stys, S.

    1991-01-01

    Coal mining causes serious disturbance of the environment. Basic principles for the reclamation of affected territories are discussed. The effects of mining on the socio-ecological landscape system, the agricultural and forestry aspects of reclamation technologies after surface mining and the factors affecting the way of reclamation are shown in a diagrammatic form. The attached photographs document the effect of mining on landscape devastation. (M.D.). 17 figs

  11. Effects of Mulching Mode on Canopy Physiological, Ecological Characteristics and Yield of Upland Rice

    OpenAIRE

    Yu-zhu ZHANG; Yang LIU; Xiang ZENG; Kai-lin CHEN; Ze-hui HUANG; Hong-ke XIE

    2011-01-01

    The effects of mulching mode on population physiology and ecology of rice were studied using a combination P88S/1128 as the material under three mulching cultivation modes including plastic film mulching, straw mulching and liquid film mulching, as well as bare cultivation (control). The results indicated that mulching mode had significant effects on micro-meteorological factors and individual growth of rice, as shown by an increase of relative humidity, a better internal micro-meteorological...

  12. Water cycles in closed ecological systems: effects of atmospheric pressure.

    Science.gov (United States)

    Rygalov, Vadim Y; Fowler, Philip A; Metz, Joannah M; Wheeler, Raymond M; Bucklin, Ray A

    2002-01-01

    In bioregenerative life support systems that use plants to generate food and oxygen, the largest mass flux between the plants and their surrounding environment will be water. This water cycle is a consequence of the continuous change of state (evaporation-condensation) from liquid to gas through the process of transpiration and the need to transfer heat (cool) and dehumidify the plant growth chamber. Evapotranspiration rates for full plant canopies can range from ~1 to 10 L m-2 d-1 (~1 to 10 mm m-2 d-1), with the rates depending primarily on the vapor pressure deficit (VPD) between the leaves and the air inside the plant growth chamber. VPD in turn is dependent on the air temperature, leaf temperature, and current value of relative humidity (RH). Concepts for developing closed plant growth systems, such as greenhouses for Mars, have been discussed for many years and the feasibility of such systems will depend on the overall system costs and reliability. One approach for reducing system costs would be to reduce the operating pressure within the greenhouse to reduce structural mass and gas leakage. But managing plant growth environments at low pressures (e.g., controlling humidity and heat exchange) may be difficult, and the effects of low-pressure environments on plant growth and system water cycling need further study. We present experimental evidence to show that water saturation pressures in air under isothermal conditions are only slightly affected by total pressure, but the overall water flux from evaporating surfaces can increase as pressure decreases. Mathematical models describing these observations are presented, along with discussion of the importance for considering "water cycles" in closed bioregenerative life support systems.

  13. Water cycles in closed ecological systems: effects of atmospheric pressure

    Science.gov (United States)

    Rygalov, Vadim Y.; Fowler, Philip A.; Metz, Joannah M.; Wheeler, Raymond M.; Bucklin, Ray A.; Sager, J. C. (Principal Investigator)

    2002-01-01

    In bioregenerative life support systems that use plants to generate food and oxygen, the largest mass flux between the plants and their surrounding environment will be water. This water cycle is a consequence of the continuous change of state (evaporation-condensation) from liquid to gas through the process of transpiration and the need to transfer heat (cool) and dehumidify the plant growth chamber. Evapotranspiration rates for full plant canopies can range from 1 to 10 L m-2 d-1 (1 to 10 mm m-2 d-1), with the rates depending primarily on the vapor pressure deficit (VPD) between the leaves and the air inside the plant growth chamber. VPD in turn is dependent on the air temperature, leaf temperature, and current value of relative humidity (RH). Concepts for developing closed plant growth systems, such as greenhouses for Mars, have been discussed for many years and the feasibility of such systems will depend on the overall system costs and reliability. One approach for reducing system costs would be to reduce the operating pressure within the greenhouse to reduce structural mass and gas leakage. But managing plant growth environments at low pressures (e.g., controlling humidity and heat exchange) may be difficult, and the effects of low-pressure environments on plant growth and system water cycling need further study. We present experimental evidence to show that water saturation pressures in air under isothermal conditions are only slightly affected by total pressure, but the overall water flux from evaporating surfaces can increase as pressure decreases. Mathematical models describing these observations are presented, along with discussion of the importance for considering "water cycles" in closed bioregenerative life support systems.

  14. Ecological validity of cost-effectiveness models of universal HPV vaccination: A systematic literature review.

    Science.gov (United States)

    Favato, Giampiero; Easton, Tania; Vecchiato, Riccardo; Noikokyris, Emmanouil

    2017-05-09

    The protective (herd) effect of the selective vaccination of pubertal girls against human papillomavirus (HPV) implies a high probability that one of the two partners involved in intercourse is immunised, hence preventing the other from this sexually transmitted infection. The dynamic transmission models used to inform immunisation policy should include consideration of sexual behaviours and population mixing in order to demonstrate an ecological validity, whereby the scenarios modelled remain faithful to the real-life social and cultural context. The primary aim of this review is to test the ecological validity of the universal HPV vaccination cost-effectiveness modelling available in the published literature. The research protocol related to this systematic review has been registered in the International Prospective Register of Systematic Reviews (PROSPERO: CRD42016034145). Eight published economic evaluations were reviewed. None of the studies showed due consideration of the complexities of human sexual behaviour and the impact this may have on the transmission of HPV. Our findings indicate that all the included models might be affected by a different degree of ecological bias, which implies an inability to reflect the natural demographic and behavioural trends in their outcomes and, consequently, to accurately inform public healthcare policy. In particular, ecological bias have the effect to over-estimate the preference-based outcomes of selective immunisation. A relatively small (15-20%) over-estimation of quality-adjusted life years (QALYs) gained with selective immunisation programmes could induce a significant error in the estimate of cost-effectiveness of universal immunisation, by inflating its incremental cost effectiveness ratio (ICER) beyond the acceptability threshold. The results modelled here demonstrate the limitations of the cost-effectiveness studies for HPV vaccination, and highlight the concern that public healthcare policy might have been

  15. Ecological effects and potential risks of the water diversion project in the Heihe River Basin.

    Science.gov (United States)

    Zhang, Mengmeng; Wang, Shuai; Fu, Bojie; Gao, Guangyao; Shen, Qin

    2018-04-01

    To curb the severe ecological deterioration in the lower Heihe River Basin (HRB) in northwest China, a water diversion project was initiated in 2000. A comprehensive analysis of the ecological effects and potential risks associated with the project is needed. We assessed the hydrological and ecological achievements, and also analyzed the potential problems after the project was completed. We found that since the project began the hydrological regime has changed, with more than 57.82% of the upstream water being discharged to the lower reaches on average. As a result, the groundwater level in the lower reaches has risen; the terminal lake has gradually expanded to a maximum area in excess of 50km 2 since 2010, and there has been a significant recovery of vegetation in the riparian zone and the Ejin core oases, which represents the initial rehabilitation of the degraded downstream environment. Additionally, the economy of Ejin has developed spectacularly, with an annual growth rate of 28.06%. However, in the middle reaches, the average groundwater level has continuously declined by a total of 5.8m and significant degradation of the vegetation has occurred along the river course. The discrepancy in the water allocation between the middle and lower reaches has intensified. This highlights the inability of the current water diversion scheme to realize further ecological restoration and achieve sustainable development throughout the whole basin. In future water management programs, we recommend that water allocation is coordinated by considering the basin as an integrated entity and to scientifically determine the size of the midstream farmland and downstream oasis; restrict non-ecological water use in the lower reaches, and jointly dispatch the surface water and groundwater. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Guidance Manual for Conducting Screening Level Ecological Risk Assessments at the INEL

    Energy Technology Data Exchange (ETDEWEB)

    R. L. VanHorn; N. L. Hampton; R. C. Morris

    1995-06-01

    This document presents reference material for conducting screening level ecological risk assessments (SLERAs)for the waste area groups (WAGs) at the Idaho National Engineering Laboratory. Included in this document are discussions of the objectives of and processes for conducting SLERAs. The Environmental Protection Agency ecological risk assessment framework is closely followed. Guidance for site characterization, stressor characterization, ecological effects, pathways of contaminant migration, the conceptual site model, assessment endpoints, measurement endpoints, analysis guidance, and risk characterization are included.

  17. Genetic Engineering and Human Mental Ecology: Interlocking Effects and Educational Considerations

    OpenAIRE

    Affifi, Ramsey

    2017-01-01

    This paper describes some likely semiotic consequences of genetic engineering on what Gregory Bateson has called ?the mental ecology? (1979) of future humans, consequences that are less often raised in discussions surrounding the safety of GMOs (genetically modified organisms). The effects are as follows: an increased 1) habituation to the presence of GMOs in the environment, 2) normalization of empirically false assumptions grounding genetic reductionism, 3) acceptance that humans are capabl...

  18. Theoretically exploring direct and indirect chemical effects across ecological and exposure scenarios using mechanistic fate and effects modelling

    NARCIS (Netherlands)

    Laender, de F.; Morselli, M.; Baveco, H.; Brink, van den P.J.; Guardo, Di A.

    2015-01-01

    Predicting ecosystem response to chemicals is a complex problem in ecotoxicology and a challenge for risk assessors. The variables potentially influencing chemical fate and exposure define the exposure scenario while the variables determining effects at the ecosystem level define the ecological

  19. Ecologically relevant geomorphic attributes of streams are impaired by even low levels of watershed effective imperviousness

    Science.gov (United States)

    Vietz, Geoff J.; Sammonds, Michael J.; Walsh, Christopher J.; Fletcher, Tim D.; Rutherfurd, Ian D.; Stewardson, Michael J.

    2014-02-01

    Urbanization almost inevitably results in changes to stream morphology. Understanding the mechanisms for such impacts is a prerequisite to minimizing stream degradation and achieving restoration goals. However, investigations of urban-induced changes to stream morphology typically use indicators of watershed urbanization that may not adequately represent degrading mechanisms and commonly focus on geomorphic attributes such as channel dimensions that may be of little significance to the ecological goals for restoration. We address these shortcomings by testing if a measure characterizing urban stormwater drainage system connections to streams (effective imperviousness, EI) is a better predictor of change to ecologically relevant geomorphic attributes than a more general measure of urban density (total imperviousness, TI). We test this for 17 sites in independent watersheds across a gradient of urbanization. We found that EI was a better predictor of all geomorphic variables tested than was TI. Bank instability was positively correlated with EI, while width/depth (a measure of channel incision), bedload sediment depth, and frequency of bars, benches, and large wood were negatively correlated. Large changes in all geomorphic variables were detected at very low levels of EI (Urbanization influences stream morphology more than any other land use (Douglas, 2011): it alters hydrology and sediment inputs leading to deepening and widening of streams (Chin, 2006). Concomitantly, urbanization often directly impairs stream morphology through channel and riparian zone interventions, e.g., culverts (Hawley et al., 2012), rock protection (Vietz et al., 2012b), and constricted floodplains (Gurnell et al., 2007). These changes to channel geomorphology in turn contribute to poor in-stream ecological condition (Morley and Karr, 2002; Walsh et al., 2005b; Gurnell et al., 2007; Elosegi et al., 2010).The common conception is that channels undergo gross morphologic alterations if > 10

  20. About the Western Ecology Division (WED) of EPA's National Health and Environmental Effects Research Laboratory

    Science.gov (United States)

    The Western Ecology Division (WED) conducts innovative research on watershed ecological epidemiology and the development of tools to achieve sustainable and resilient watersheds for application by stakeholders.

  1. Ecological effects of harvesting biomass for energy in the Spanish Mediterranean

    International Nuclear Information System (INIS)

    Zavala, Miguel A.; Marcos, Francisco

    1993-01-01

    Biomass utilization for energy has major consequences for Spanish Mediterranean landscapes. In this paper we present a synthesis of the ecological effects of harvesting biomass for energy. We compare these effects with other fuel reduction procedures such as prescribed burning. Throughout history we see that some Iberian ecosystems are stabilized by long human interference. One of the stabilizing factors is the utilization of wood as a source of energy. New energy sources and massive human movements towards urban areas have changed the ecosystem dynamics. Reforested areas in Spain during the period from 1940 to 1970 included silviculture treatments that in some cases never took place. This has led to a greater accumulation of biomass. The current perspective of the problem must be analyzed from an economic and political viewpoint. For instance, the Middle East crisis has direct consequences for the budget dedicated to forest energetics, and consequently for the landscape. This shows how ecological problems must be dealt with using a very broad perspective. In Spain current biomass usage should be considered primarily as a complementary silvicultural treatment rather than as a way of producing great biomass outputs. If we are going to manage our forest from an ecological perspective, we have to analyze the effects of these operations at the stand level. At the landscape level fuel management plans should be included in the Forest Management Prescriptions (ordenaciones) whether in terms of harvesting or in a prescribed burning plan

  2. Introducing Meta-Partition, a Useful Methodology to Explore Factors That Influence Ecological Effect Sizes.

    Directory of Open Access Journals (Sweden)

    Zaida Ortega

    Full Text Available The study of the heterogeneity of effect sizes is a key aspect of ecological meta-analyses. Here we propose a meta-analytic methodology to study the influence of moderators in effect sizes by splitting heterogeneity: meta-partition. To introduce this methodology, we performed a meta-partition of published data about the traits that influence species sensitivity to habitat loss, that have been previously analyzed through meta-regression. Thus, here we aim to introduce meta-partition and to make an initial comparison with meta-regression. Meta-partition algorithm consists of three steps. Step 1 is to study the heterogeneity of effect sizes under the assumption of fixed effect model. If heterogeneity is found, we perform step 2, that is, to partition the heterogeneity by the moderator that minimizes heterogeneity within a subset while maximizing heterogeneity between subsets. Then, if effect sizes of the subset are still heterogeneous, we repeat step 1 and 2 until we reach final subsets. Finally, step 3 is to integrate effect sizes of final subsets, with fixed effect model if there is homogeneity, and with random effects model if there is heterogeneity. Results show that meta-partition is valuable to assess the importance of moderators in explaining heterogeneity of effect sizes, as well as to assess the directions of these relations and to detect possible interactions between moderators. With meta-partition we have been able to evaluate the importance of moderators in a more objective way than with meta-regression, and to visualize the complex relations that may exist between them. As ecological issues are often influenced by several factors interacting in complex ways, ranking the importance of possible moderators and detecting possible interactions would make meta-partition a useful exploration tool for ecological meta-analyses.

  3. [Ecology and ecologies].

    Science.gov (United States)

    Valera, Luca

    2011-01-01

    Ecology (from the Greek words οιχοσ, "house" and λογια "study of") is the science of the "house", since it studies the environments where we live. There are three main ways of thinking about Ecology: Ecology as the study of interactions (between humans and the environment, between humans and living beings, between all living beings, etc.), Ecology as the statistical study of interactions, Ecology as a faith, or rather as a science that requires a metaphysical view. The history of Ecology shows us how this view was released by the label of "folk sense" to gain the epistemological status of science, a science that strives to be interdisciplinary. So, the aim of Ecology is to study, through a scientific methodology, the whole natural world, answering to very different questions, that arise from several fields (Economics, Biology, Sociology, Philosophy, etc.). The plurality of issues that Ecology has to face led, during the Twentieth-century, to branch off in several different "ecologies". As a result, each one of these new approaches chose as its own field a more limited and specific portion of reality.

  4. Estimating the Cumulative Ecological Effect of Local Scale Landscape Changes in South Florida

    Science.gov (United States)

    Hogan, Dianna M.; Labiosa, William; Pearlstine, Leonard; Hallac, David; Strong, David; Hearn, Paul; Bernknopf, Richard

    2012-01-01

    Ecosystem restoration in south Florida is a state and national priority centered on the Everglades wetlands. However, urban development pressures affect the restoration potential and remaining habitat functions of the natural undeveloped areas. Land use (LU) planning often focuses at the local level, but a better understanding of the cumulative effects of small projects at the landscape level is needed to support ecosystem restoration and preservation. The South Florida Ecosystem Portfolio Model (SFL EPM) is a regional LU planning tool developed to help stakeholders visualize LU scenario evaluation and improve communication about regional effects of LU decisions. One component of the SFL EPM is ecological value (EV), which is evaluated through modeled ecological criteria related to ecosystem services using metrics for (1) biodiversity potential, (2) threatened and endangered species, (3) rare and unique habitats, (4) landscape pattern and fragmentation, (5) water quality buffer potential, and (6) ecological restoration potential. In this article, we demonstrate the calculation of EV using two case studies: (1) assessing altered EV in the Biscayne Gateway area by comparing 2004 LU to potential LU in 2025 and 2050, and (2) the cumulative impact of adding limestone mines south of Miami. Our analyses spatially convey changing regional EV resulting from conversion of local natural and agricultural areas to urban, industrial, or extractive use. Different simulated local LU scenarios may result in different alterations in calculated regional EV. These case studies demonstrate methods that may facilitate evaluation of potential future LU patterns and incorporate EV into decision making.

  5. Using latent effects to determine the ecological importance of dissolved organic matter to marine invertebrates.

    Science.gov (United States)

    Wendt, Dean E; Johnson, Collin H

    2006-10-01

    The uptake and utilization of dissolved organic matter (DOM) by marine invertebrates is a field that has received significant attention over the past 100 years. Although it is well established that DOM is taken up by marine invertebrates, the extent to which it contributes to an animal's survival, growth, and reproduction (that is, the ecological benefits) remains largely unknown. Previous work seeking to demonstrate the putative ecological benefits of DOM uptake have examined them within a single life stage of an animal. Moreover, most of the benefits are demonstrated through indirect approaches by examining (1) mass balance, or (2) making comparisons of oxyenthalpic conversions of transport rates to metabolic rate as judged by oxygen consumption. We suggest that directly examining delayed metamorphosis or the latent effects associated with nutritional stress of larvae is a better model for investigating the ecological importance of DOM to marine invertebrates. We also provide direct evidence that availability of DOM enhances survival and growth of the bryozoan Bugula neritina. That DOM offsets latent effects in B. neritina suggests that the underlying mechanisms are at least in part energetic.

  6. 2000 Benthic and Landcover Characterization of Salt River Bay National Historical Park and Ecological Preserve, St Coix, USVI

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Habitat maps were created as part of a larger ecological assessment conducted by NOAA's National Ocean Service (NOS), Biogeography Program, for Salt River Bay...

  7. About the Mid-Continent Ecology Division (MED) of EPA's National Health and Environmental Effects Research Laboratory

    Science.gov (United States)

    The Mid-Continent Ecology Division (MED) conducts innovative research and predictive modeling to document and forecast the effects of pollutants on the integrity of watersheds and freshwater ecosystems.

  8. A brief introduction to mixed effects modelling and multi-model inference in ecology.

    Science.gov (United States)

    Harrison, Xavier A; Donaldson, Lynda; Correa-Cano, Maria Eugenia; Evans, Julian; Fisher, David N; Goodwin, Cecily E D; Robinson, Beth S; Hodgson, David J; Inger, Richard

    2018-01-01

    The use of linear mixed effects models (LMMs) is increasingly common in the analysis of biological data. Whilst LMMs offer a flexible approach to modelling a broad range of data types, ecological data are often complex and require complex model structures, and the fitting and interpretation of such models is not always straightforward. The ability to achieve robust biological inference requires that practitioners know how and when to apply these tools. Here, we provide a general overview of current methods for the application of LMMs to biological data, and highlight the typical pitfalls that can be encountered in the statistical modelling process. We tackle several issues regarding methods of model selection, with particular reference to the use of information theory and multi-model inference in ecology. We offer practical solutions and direct the reader to key references that provide further technical detail for those seeking a deeper understanding. This overview should serve as a widely accessible code of best practice for applying LMMs to complex biological problems and model structures, and in doing so improve the robustness of conclusions drawn from studies investigating ecological and evolutionary questions.

  9. An ecosystem services approach to the ecological effects of salvage logging: valuation of seed dispersal.

    Science.gov (United States)

    Leverkus, Alexandro B; Castro, Jorge

    2017-06-01

    Forest disturbances diminish ecosystem services and boost disservices. Because post-disturbance management intends to recover the greatest possible value, selling timber often prevails over other considerations. Ecological research has shown diverse effects of salvage logging, yet such research has focused on the biophysical component of post-disturbance ecosystems and lacks the link with human well-being. Here we bridge that gap under the ecosystem services framework by assessing the impact of post-fire management on a non-timber value. By employing the replacement cost method, we calculated the value of the post-fire natural regeneration of Holm oaks in southern Spain under three post-fire management options by considering the cost of planting instead. The value of this ecosystem service in non-intervention areas doubled that of salvage-logged stands due to the preference for standing dead trees by the main seed disperser. Still, most of the value resulted from the resprouting capacity of oaks. The value of this and other ecosystem services should be added to traditional cost/benefit analyses of post-disturbance management. We thus call for a more holistic approach to salvage logging research, one that explicitly links ecological processes with human well-being through ecosystem services, to better inform decision-makers on the outcomes of post-disturbance management. © 2017 by the Ecological Society of America.

  10. Functional group, biomass, and climate change effects on ecological drought in semiarid grasslands

    Science.gov (United States)

    Wilson, Scott D.; Schlaepfer, Daniel R.; Bradford, John B.; Lauenroth, William K.; Duniway, Michael C.; Hall, Sonia A.; Jamiyansharav, Khishigbayar; Jia, Gensuo; Lkhagva, Ariuntsetseg; Munson, Seth M.; Pyke, David A.; Tietjen, Britta

    2018-01-01

    Water relations in plant communities are influenced both by contrasting functional groups (grasses, shrubs) and by climate change via complex effects on interception, uptake and transpiration. We modelled the effects of functional group replacement and biomass increase, both of which can be outcomes of invasion and vegetation management, and climate change on ecological drought (soil water potential below which photosynthesis stops) in 340 semiarid grassland sites over 30‐year periods. Relative to control vegetation (climate and site‐determined mixes of functional groups), the frequency and duration of drought were increased by shrubs and decreased by annual grasses. The rankings of shrubs, control vegetation, and annual grasses in terms of drought effects were generally consistent in current and future climates, suggesting that current differences among functional groups on drought effects predict future differences. Climate change accompanied by experimentally‐increased biomass (i.e. the effects of invasions that increase community biomass, or management that increases productivity through fertilization or respite from grazing) increased drought frequency and duration, and advanced drought onset. Our results suggest that the replacement of perennial temperate semiarid grasslands by shrubs, or increased biomass, can increase ecological drought both in current and future climates.

  11. Ecological effects of aphid abundance, genotypic variation, and contemporary evolution on plants.

    Science.gov (United States)

    Turley, Nash E; Johnson, Marc T J

    2015-07-01

    Genetic variation and contemporary evolution within populations can shape the strength and nature of species interactions, but the relative importance of these forces compared to other ecological factors is unclear. We conducted a field experiment testing the effects of genotypic variation, abundance, and presence/absence of green peach aphids (Myzus persicae) on the growth, leaf nitrogen, and carbon of two plant species (Brassica napus and Solanum nigrum). Aphid genotype affected B. napus but not S. nigrum biomass explaining 20 and 7% of the total variation, respectively. Averaging across both plant species, the presence/absence of aphids had a 1.6× larger effect size (Cohen's d) than aphid genotype, and aphid abundance had the strongest negative effects on plant biomass explaining 29% of the total variation. On B. napus, aphid genotypes had different effects on leaf nitrogen depending on their abundance. Aphids did not influence leaf nitrogen in S. nigrum nor leaf carbon in either species. We conducted a second experiment in the field to test whether contemporary evolution could affect plant performance. Aphid populations evolved in as little as five generations, but the rate and direction of this evolution did not consistently vary between plant species. On one host species (B. napus), faster evolving populations had greater negative effects on host plant biomass, with aphid evolutionary rate explaining 23% of the variation in host plant biomass. Together, these results show that genetic variation and evolution in an insect herbivore can play important roles in shaping host plant ecology.

  12. Effects of silvicultural activity on ecological processes in floodplain forests of the southern United States

    International Nuclear Information System (INIS)

    Lockaby, B.G.; Stanturf, J.A.

    1996-01-01

    Activities associated with timber harvesting have occurred within floodplain forests in the southern United States for nearly two hundred years. However, it is only in the last ten years that any information has become available about the effects of harvesting on the ecological functions of this valuable resource. Hydrology is the driving influence behind all ecological processes in floodplains and, in most cases, timber harvesting alone has little long-term effect on hydroperiod. However, there may be some instances where logging roads, built in association with harvest sites , can alter hydroperiod to the extent that vegetation productivity is altered positively or negatively. There is no documentation that harvesting followed by natural regeneration represents a threat to ground or surface water quality on floodplain sites, as long as Best Management Practices are followed. Harvested floodplains may increase or have little effect on decomposition rates of surface organic matter. The nature of the effect seems to be controlled by site wetness. Data from recently harvested sites (i.e. within the last ten years) suggest that vegetation productivity is maintained at levels similar to that observed prior to harvests. During the early stages of stand development vegetation species composition is heavily influenced by harvest method. Similarly, amphibian populations (monitored as bioindicators of ecosystem recovery) seem to rebound rapidly following harvests, although species composition may be different. 40 refs, 3 figs

  13. Spatial variation in the flux of atmospheric deposition and its ecological effects in arid Asia

    Science.gov (United States)

    Jiao, Linlin; Wang, Xunming; Li, Danfeng

    2018-06-01

    Atmospheric deposition is one of the key land surface processes, and plays important roles in regional ecosystems and global climate change. Previous studies have focused on the magnitude of and the temporal and spatial variations in the flux of atmospheric deposition, and the composition of atmospheric deposition on a local scale. However, there have been no comprehensive studies of atmospheric deposition on a regional scale and its ecological effects in arid Asia. The temporal and spatial patterns, composition of atmospheric deposition, and its potential effects on regional ecosystems in arid Asia are investigated in this study. The results show that the annual deposition flux is high on the Turan Plain, Aral Sea Desert, and Tarim Basin. The seasonal deposition flux also varies remarkably among different regions. The Tarim Basin shows higher deposition flux in both spring and summer, southern Mongolian Plateau has a higher deposition flux in spring, and the deposition flux of Iran Plateau is higher in summer. Multiple sources of elements in deposited particles are identified. Calcium, iron, aluminum, and magnesium are mainly derived from remote regions, while zinc, copper and lead have predominantly anthropogenic sources. Atmospheric deposition can provide abundant nutrients to vegetation and consequently play a role in the succession of regional ecosystems by affecting the structure, function, diversity, and primary production of the vegetation, especially the exotic or short-lived opportunistic species in arid Asia. Nevertheless, there is not much evidence of the ecological effects of atmospheric deposition on the regional and local scale. The present results may help in further understanding the mechanism of atmospheric deposition as well as providing a motivation for the protection of the ecological environment in arid Asia.

  14. Effective ecological half-lives of Cs-137 for fishes controlled by their surrounding sea-waters

    International Nuclear Information System (INIS)

    Morita, T.; Yoshida, K.

    2004-01-01

    National Research Institute of Fisheries Science (NRIFS) has carried out the long term monitoring program for radioactive pollution in marine organisms caught around Japan in order to confirm the safety of marine organisms as food source. Main radionuclide in our monitoring program is Cs-137 because it has the relatively high radiotoxicity and the long term physical half-life (about 30.1 y), and tends to accumulate in the muscle. Recently, the effective ecological half-lives have been introduced to estimate the recovery time from radioactive pollution, and been applicable to various ecosystems. In this study, effective ecological half-lives of Cs-137 for some fishes were calculated from our long term monitoring data. It is known that fish species have each effective ecological half-lives. However, it has been unclear what change the effective ecological half-lives of Cs-137 for fishes. Fishes intake Cs-137 through food chain and directly from their surrounding sea-waters. Accordingly, the effective ecological half-lives of Cs-137 for some fishes would be controlled by the effective environment half-lives of Cs-137 for their surrounding sea-waters. There is difference in effective environment half-lives of Cs-137 between the open ocean and the coastal sea-waters because they have the different input sources of Cs-137. Some fishes move between the open ocean and the coastal areas, and therefore their effective ecological half-lives of Cs-137 are influenced by the effective environment half-lives of Cs-137 for sea-waters of both areas. Consequently, the differences in effective ecological half-lives of Cs-137 among fish species would depend the rate of coastal area in their lives. (author)

  15. Contemporary pollen flow, characterization of the maternal ecological neighbourhood and mating patterns in wild cherry (Prunus avium L.).

    Science.gov (United States)

    Cottrell, J E; Vaughan, S P; Connolly, T; Sing, L; Moodley, D J; Russell, K

    2009-08-01

    Conversion of lowland woodland to agricultural land and resulting fragmentation in Britain has been ongoing since Neolithic times. To counteract this decline, plantations of native species, often based on non-British planting stock, have been established. This may ultimately be detrimental to the integrity of the native gene pool. We explore the genetic and ecological factors influencing the success of components of the local pollen pool, including the effect of a non-native planting on an ancient woodland population of wild cherry. Wild cherry exhibits gametophytic self-incompatibility (GSI) and vegetative reproduction, both of which may be determinants of paternal success. The majority (61%) of the successful pollen originated from within the study site with a maximum pollen transfer distance of 694 m. There was a distinct departure from random mating, with over half the successful pollen originating from trees which occur within 100 m of the mother tree. Self-incompatibility, clonality, tree size and proximity to the mother tree were all found to influence paternal success. Kinship of pollen gametes within a maternal progeny was highest when a mother tree was surrounded by a large number of ramets of a single, compatible clone consisting of large, adult trees. Although the contribution from the non-native plantation is currently low, it is likely that this will increasingly contribute to the progeny of the adjacent ancient population as it matures. The results clearly show that in self-incompatible species, such as P. avium, close neighbours may be pollinated by very different components of the local pollen pool.

  16. Effectiveness of teams: Lessons from biomimicry, an ecological inquiry E=MC

    Directory of Open Access Journals (Sweden)

    Sivave Mashingaidze

    2015-07-01

    Full Text Available Team effectiveness in swarms like bees, colonies of ants, schools of fish, flocks of birds, and fireflies flashing synchronously are all as a result of highly coordinated behaviors that emerge from collective, decentralized intelligence. The purpose of this article was to conduct an ecological research inquiry of what lessons business can borrow from biomimicry especially by studying ants’ colonies, swarm of bees and packs of wild African dogs. A systems science theory borrowed from Albeit Einstein E = mc2 was used, where effectiveness of teams was equal to mastery of each individual x coordination x communication (collective intelligence. The author used using secondary data analysis to obtain information on team effectiveness and collective intelligence. The research found out that, team effectiveness is a function of mastery of individual x coordination x communication (collective intelligence. The research further recommended corporate to mimic the biosphere especially to adopt collective intelligence strategies from ants, swarm of bees and wild dogs for business sustainability

  17. Mechanistic effect modeling for ecological risk assessment: where to go from here?

    Science.gov (United States)

    Grimm, Volker; Martin, Benjamin T

    2013-07-01

    Mechanistic effect models (MEMs) consider the mechanisms of how chemicals affect individuals and ecological systems such as populations and communities. There is an increasing awareness that MEMs have high potential to make risk assessment of chemicals more ecologically relevant than current standard practice. Here we discuss what kinds of MEMs are needed to improve scientific and regulatory aspects of risk assessment. To make valid predictions for a wide range of environmental conditions, MEMs need to include a sufficient amount of emergence, for example, population dynamics emerging from what individual organisms do. We present 1 example where the life cycle of individuals is described using Dynamic Energy Budget theory. The resulting individual-based population model is thus parameterized at the individual level but correctly predicts multiple patterns at the population level. This is the case for both control and treated populations. We conclude that the state-of-the-art in mechanistic effect modeling has reached a level where MEMs are robust and predictive enough to be used in regulatory risk assessment. Mechanistic effect models will thus be used to advance the scientific basis of current standard practice and will, if their development follows Good Modeling Practice, be included in a standardized way in future regulatory risk assessments. Copyright © 2013 SETAC.

  18. A review of ecological effects and environmental fate of illicit drugs in aquatic ecosystems.

    Science.gov (United States)

    Rosi-Marshall, E J; Snow, D; Bartelt-Hunt, S L; Paspalof, A; Tank, J L

    2015-01-23

    Although illicit drugs are detected in surface waters throughout the world, their environmental fate and ecological effects are not well understood. Many illicit drugs and their breakdown products have been detected in surface waters and temporal and spatial variability in use translates into "hot spots and hot moments" of occurrence. Illicit drug occurrence in regions of production and use and areas with insufficient wastewater treatment are not well studied and should be targeted for further study. Evidence suggests that illicit drugs may not be persistent, as their half-lives are relatively short, but may exhibit "pseudo-persistence" wherein continual use results in persistent occurrence. We reviewed the literature on the ecological effects of these compounds on aquatic organisms and although research is limited, a wide array of aquatic organisms, including bacteria, algae, invertebrates, and fishes, have receptors that make them potentially sensitive to these compounds. In summary, illicit drugs occur in surface waters and aquatic organisms may be affected by these compounds; research is needed that focuses on concentrations of illicit drugs in areas of production and high use, environmental fate of these compounds, and effects of these compounds on aquatic ecosystems at the concentrations that typically occur in the environment. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Restoring fish ecological quality in estuaries: Implication of interactive and cumulative effects among anthropogenic stressors.

    Science.gov (United States)

    Teichert, Nils; Borja, Angel; Chust, Guillem; Uriarte, Ainhize; Lepage, Mario

    2016-01-15

    Estuaries are subjected to multiple anthropogenic stressors, which have additive, antagonistic or synergistic effects. Current challenges include the use of large databases of biological monitoring surveys (e.g. the European Water Framework Directive) to help environmental managers prioritizing restoration measures. This study investigated the impact of nine stressor categories on the fish ecological status derived from 90 estuaries of the North East Atlantic countries. We used a random forest model to: 1) detect the dominant stressors and their non-linear effects; 2) evaluate the ecological benefits expected from reducing pressure from stressors; and 3) investigate the interactions among stressors. Results showed that largest restoration benefits were expected when mitigating water pollution and oxygen depletion. Non-additive effects represented half of pairwise interactions among stressors, and antagonisms were the most common. Dredged sediments, flow changes and oxygen depletion were predominantly implicated in non-additive interactions, whereas the remainder stressors often showed additive impacts. The prevalence of interactive impacts reflects a complex scenario for estuaries management; hence, we proposed a step-by-step restoration scheme focusing on the mitigation of stressors providing the maximum of restoration benefits under a multi-stress context. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Ecological behavior and effects of energy related pollutants. Progress report, June 1976--August 1977

    International Nuclear Information System (INIS)

    Platt, R.B.; Ragsdale, H.L.; Murdy, W.H.; Shure, D.J.

    1977-01-01

    The impact of SO 2 on the survival and stability of plant populations and communities was studied. The results to date have an important bearing on the adequacy of current permissible ambient air levels for SO 2 . Atmospheric SO 2 concentrations at near permissible levels had a significant adverse effect on sexual reproduction processes, which results in a reduced number of viable seeds, in all 8 populations tested. Implications for both natural and agricultural plant species and possible significant losses of fruit production are discussed. An ecological implication of the invisible effect of fruit and seed mortality is postulated since the life cycle of many insects and the trophic relations of numerous animals depend, at least in part, on fruit production by trees and shrubs. Hence, there is a potential for disruptive effects on ecosystem level processes. Results are also reported from four systems-oriented studies within the Lower Three Runs Creek Watershed, Savannah River Plant, to examine fallout 137 Cs transfer processes in ecological systems characteristic of the Southeastern Coastal Plain. These studies were carried out within the stream and its floodplains, within floodplains along the stream gradient, in upland aquatic systems (Carolina Bays), and in the upland scrub-oak forest system. Results are discussed

  1. Carnivore repatriation and holarctic prey: narrowing the deficit in ecological effectiveness.

    Science.gov (United States)

    Berger, Joel

    2007-08-01

    The continuing global decline of large carnivores has catalyzed great interest in reintroduction to restore populations and to reestablish ecologically functional relationships. I used variation in the distribution of four Holarctic prey species and their behavior as proxies to investigate the pace and intensity by which responses are lost or reinvigorated by carnivore repatriation. By simulating the presence of wolves (Canis lupus), tigers (Panthera tigris), and brown bears (Ursus arctos) at 19 transcontinental sites, I assayed three metrics of prey performance in areas with no large terrestrial carnivores (the polar islands of Greenland and Svalbard), extant native carnivores (Eastern Siberian Shield, boreal Canada, and Alaska); and repatriated carnivores (the Yellowstone region and Rocky Mountains). The loss and reestablishment of large carnivores changed the ecological effectiveness of systems by (1) dampening immediate group benefits, diminishing awareness, and diminishing flight reaction in caribou (Rangifer tarandus) where predation was eliminated and (2) reinstituting sensitivity to carnivores by elk (Cervus elaphus) and moose (Alces alces) in the Yellowstone region to levels observed in Asian elk when sympatric with Siberian tigers and wolves or in Alaskan moose sympatric with wolves. Behavioral compensation to reintroduced carnivores occurred within a single generation, but only the vigilance reaction of bison (Bison bison) in Yellowstone exceeded that of their wolf-exposed conspecifics from boreal Canada. Beyond these overt responses by prey, snow depth and distance to suitably vegetated habitat was related to heightened vigilance in moose and elk, respectively, but only at sites with carnivores. These findings are insufficient to determine whether similar patterns might apply to other species or in areas with alien predators, and they suggest that the presumed excessive vulnerability of naïve prey to repatriated carnivores may be ill-founded. Although

  2. Graphic Ecologies

    Directory of Open Access Journals (Sweden)

    Brook Weld Muller

    2014-12-01

    Full Text Available This essay describes strategic approaches to graphic representation associated with critical environmental engagement and that build from the idea of works of architecture as stitches in the ecological fabric of the city. It focuses on the building up of partial or fragmented graphics in order to describe inclusive, open-ended possibilities for making architecture that marry rich experience and responsive performance. An aphoristic approach to crafting drawings involves complex layering, conscious absence and the embracing of tension. A self-critical attitude toward the generation of imagery characterized by the notion of ‘loose precision’ may lead to more transformative and environmentally responsive architectures.

  3. Ecological effects of invasive alien species on native communities, with particular emphasis on the interactions between aphids and ladybirds

    Czech Academy of Sciences Publication Activity Database

    Kindlmann, Pavel; Ameixa, Olga; Dixon, Anthony F. G.

    2011-01-01

    Roč. 56, č. 4 (2011), s. 469-476 ISSN 1386-6141 R&D Projects: GA MŠk LC06073; GA MŠk(CZ) ED1.1.00/02.0073 Institutional research plan: CEZ:AV0Z60870520 Keywords : invasive alien species * predators * insect pest s * ecological effects * intraguild predation Subject RIV: EH - Ecology, Behaviour Impact factor: 1.927, year: 2011

  4. Ecological effects of ionizing radiation and other toxic agents on the aquatic microcosm

    International Nuclear Information System (INIS)

    Fuma, Shoichi; Ishii, Nobuyoshi; Tanaka, Nobuyuki; Takeda, Hiroshi; Miyamoto, Kiriko; Yanagisawa, Kei; Kawabata, Zen'ichiro

    2004-01-01

    The purpose of this study was comparative evaluation of effects of ionizing radiation and other various toxic agents on aquatic microbial communities. For this purpose, the authors investigated effects of γ-rays, ultraviolet (UV) radiation, acidification, aluminum, manganese, nickel, copper and gadolinium on the microcosm, i.e., the experimental model ecosystem consisting of populations of the flagellate alga Euglena gracilis as a producer, the ciliate protozoan Tetrahymena thermophila as a consumer and the bacterium Eseherichia coli as a decomposer. Effects of toxic agents in the microcosm were not only direct effects but also community-level effects due to interactions among the constituting species or between organisms and toxic agents. In general, the degrees of effects observed in the microcosm could be categorized as follows: no effects; recognizable effects, i.e., decrease or increase in the cell densities of at least one species; severe effects, i.e., extinction of one or two species; and destructive effects, i.e., extinction of all species. These results were analyzed by the ecological effect index (EEI), in which differences in the cell densities between exposed and control microcosm were represented by the Euclidean distance function. A 50% effect doses for the microcosm (ED M50 ), at which the EEI became 50%, were evaluated to be 530 Gy for γ-rays, 2100 J m -2 for UV, 4100 μM for manganese, 45 μM for nickel, 110 μM for copper and 250 μM for gadolinium. (author)

  5. Central-place foraging and ecological effects of an invasive predator across multiple habitats.

    Science.gov (United States)

    Benkwitt, Cassandra E

    2016-10-01

    Cross-habitat foraging movements of predators can have widespread implications for predator and prey populations, community structure, nutrient transfer, and ecosystem function. Although central-place foraging models and other aspects of optimal foraging theory focus on individual predator behavior, they also provide useful frameworks for understanding the effects of predators on prey populations across multiple habitats. However, few studies have examined both the foraging behavior and ecological effects of nonnative predators across multiple habitats, and none has tested whether nonnative predators deplete prey in a manner predicted by these foraging models. I conducted behavioral observations of invasive lionfish (Pterois volitans) to determine whether they exhibit foraging movements similar to other central-place consumers. Then, I used a manipulative field experiment to test whether their effects on prey populations are consistent with three qualitative predictions from optimal foraging models. Specifically, I predicted that the effects of invasive lionfish on native prey will (1) occur at central sites first and then in surrounding habitats, (2) decrease with increasing distance away from their shelter site, and (3) extend to greater distances when prey patches are spaced closer together. Approximately 40% of lionfish exhibited short-term crepuscular foraging movements into surrounding habitats from the coral patch reefs where they shelter during daylight hours. Over the course of 7 weeks, lionfish depleted native fish populations on the coral patch reefs where they reside, and subsequently on small structures in the surrounding habitat. However, their effects did not decrease with increasing distance from the central shelter site and the influence of patch spacing was opposite the prediction. Instead, lionfish always had the greatest effects in areas with the highest prey densities. The differences between the predicted and observed effects of lionfish

  6. Ecological effects of various toxic agents on the aquatic microcosm in comparison with acute ionizing radiation

    International Nuclear Information System (INIS)

    Fuma, S.; Ishii, N.; Takeda, H.; Miyamoto, K.; Yanagisawa, K.; Ichimasa, Y.; Saito, M.; Kawabata, Z.; Polikarpov, G.G.

    2003-01-01

    The purpose of this study was an evaluation of the effect levels of various toxic agents compared with acute doses of ionizing radiation for the experimental model ecosystem, i.e., microcosm mimicking aquatic microbial communities. For this purpose, the authors used the microcosm consisting of populations of the flagellate alga Euglena gracilis as a producer, the ciliate protozoan Tetrahymena thermophila as a consumer and the bacterium Escherichia coli as a decomposer. Effects of aluminum and copper on the microcosm were investigated in this study, while effects of γ-rays, ultraviolet radiation, acidification, manganese, nickel and gadolinium were reported in previous studies. The microcosm could detect not only the direct effects of these agents but also the community-level effects due to the interspecies interactions or the interactions between organisms and toxic agents. The authors evaluated doses or concentrations of each toxic agent which had the following effects on the microcosm: (1) no effects; (2) recognizable effects, i.e., decrease or increase in the cell densities of at least one species; (3) severe effects, i.e., extinction of one or two species; and (4) destructive effects, i.e., extinction of all species. The resulting effects data will contribute to an ecological risk assessment of the toxic agents compared with acute doses of ionizing radiation

  7. Ecological impacts of umbrella effects of radiation on the individual members

    International Nuclear Information System (INIS)

    Doi, Masahiro; Kawaguchi, Isao

    2007-01-01

    In order to study the interactions in a model aquatic microcosm, an individual-based computer simulation model was developed. The microcosm consists of Euglena gracilis as an autotroph algae, Tetrahymena thermophila as a heterotroph protozoa and Escherichia coli as a saprotroph bacteria. There exists a strong interaction between Tetrahymena and E. coli as the first is the predator of the second. Ecological toxicity tests were conducted to test the population level impacts of the biological effects of radiation and toxicants on the lethality and mobility factors that influence directly or indirectly growth and reproduction. Radiological effects on lethality of E. coli individuals were translated to the reduction of the equilibrium population of Tetrahymena. A synergistic effect at the community level was also observed by the simulation of a combined exposure of radiation and a toxicant which reduced the feeding efficiency of Tetrahymena

  8. Methodologies for assessment of power plant ecological effects in the marine environment

    International Nuclear Information System (INIS)

    Adams, S.M.

    1978-01-01

    Various types of models or methodologies relevant to the assessment of entrainment, thermal, and impingement impacts of power plant operation in the marine environment are presented. The majority of methodologies available for assessing power plant effects are focused at the organism or population level. The most widely applied approaches for estimating entrainment effects on fish populations are the equivalent adult and trophic-conversion methodologies. Current methods to predict the number of fish and distribution of species impinged consider physical factors of the environment but not the biological or behavorial characteristics of fish. With proper validation, ecosystem-level models that consider aggregate responses of biological components to stress may prove to be a viable approach for investigating power plant ecological effects

  9. Ecological effects of nitrogen and sulfur air pollution in the US: what do we know?

    Science.gov (United States)

    Greaver, Tara L.; Sullivan, Timothy J.; Herrick, Jeffrey D.; Barber, Mary C.; Baron, Jill S.; Cosby, Bernard J.; Deerhake, Marion E.; Dennis, Robin L.; Dubois, Jean-Jacque B.; Goodale, Christine L.; Herlihy, Alan T.; Lawrence, Gregory B.; Liu, Lingli; Lynch, Jason A.; Novak, Kristopher J.

    2012-01-01

    Four decades after the passage of the US Clean Air Act, air-quality standards are set to protect ecosystems from damage caused by gas-phase nitrogen (N) and sulfur (S) compounds, but not from the deposition of these air pollutants to land and water. Here, we synthesize recent scientific literature on the ecological effects of N and S air pollution in the US. Deposition of N and S is the main driver of ecosystem acidification and contributes to nutrient enrichment in many natural systems. Although surface-water acidification has decreased in the US since 1990, it remains a problem in many regions. Perturbations to ecosystems caused by the nutrient effects of N deposition continue to emerge, although gas-phase concentrations are generally not high enough to cause phytotoxicity. In all, there is overwhelming evidence of a broad range of damaging effects to ecosystems in the US under current air quality conditions.

  10. Effects of climate change on ecological disturbance in the Northern Rockies Region [Chapter 8

    Science.gov (United States)

    Loehman, Rachel A.; Bentz, Barbara J.; DeNitto, Gregg A.; Keane, Robert E.; Manning, Mary E.; Duncan, Jacob P.; Egan, Joel M.; Jackson, Marcus B.; Kegley, Sandra; Lockman, I. Blakey; Pearson, Dean E.; Powell, James A.; Shelly, Steve; Steed, Brytten E.; Zambino, Paul J.

    2018-01-01

    This chapter describes the ecology of important disturbance regimes in the Forest Service, U.S. Department of Agriculture (USFS) Northern Region and the Greater Yellowstone Area, hereafter called the Northern Rockies region, and potential shifts in these regimes as a consequence of observed and projected climate change. The term disturbance regime describes the general temporal and spatial characteristics of a disturbance agent - insect, disease, fire, weather, even human activity - and the effects of that agent on the landscape (table 8.1). More specifically, a disturbance regime is the cumulative effect of multiple disturbance events over space and time (Keane 2013). Disturbances disrupt an ecosystem, community, or population structure and change elements of the biological environment, physical environment, or both (White and Pickett 1985). The resulting shifting mosaic of diverse ecological patterns and structures in turn affects future patterns of disturbance, in a reciprocal, linked relationship that shapes the fundamental character of landscapes and ecosystems. Disturbance creates and maintains biological diversity in the form of shifting, heterogeneous mosaics of diverse communities and habitats across a landscape (McKinney and Drake 1998), and biodiversity is generally highest when disturbance is neither too rare nor too frequent on the landscape (Grime 1973).

  11. Social Interface Model: Theorizing Ecological Post-Delivery Processes for Intervention Effects.

    Science.gov (United States)

    Pettigrew, Jonathan; Segrott, Jeremy; Ray, Colter D; Littlecott, Hannah

    2018-01-03

    Successful prevention programs depend on a complex interplay among aspects of the intervention, the participant, the specific intervention setting, and the broader set of contexts with which a participant interacts. There is a need to theorize what happens as participants bring intervention ideas and behaviors into other life-contexts, and theory has not yet specified how social interactions about interventions may influence outcomes. To address this gap, we use an ecological perspective to develop the social interface model. This paper presents the key components of the model and its potential to aid the design and implementation of prevention interventions. The model is predicated on the idea that intervention message effectiveness depends not only on message aspects but also on the participants' adoption and adaptation of the message vis-à-vis their social ecology. The model depicts processes by which intervention messages are received and enacted by participants through social processes occurring within and between relevant microsystems. Mesosystem interfaces (negligible interface, transference, co-dependence, and interdependence) can facilitate or detract from intervention effects. The social interface model advances prevention science by theorizing that practitioners can create better quality interventions by planning for what occurs after interventions are delivered.

  12. Ecological effects research related to oil spills and oil spill countermeasures

    International Nuclear Information System (INIS)

    Aurand, D.

    1992-01-01

    The Marine Spill Response Corporation (MSRC) was created specifically to provide an improved response option for large marine oil spills in U.S. waters. As part of that capability, MSRC is committed to an extensive research and development program designed to improve the state-of-the-art for oil spill response. Within the mission, the goals of the Environmental Health Program are to ensure that ecological and human health effects of both oil and oil cleanup counter measures are well understood and that this information is made widely available for appropriate consideration in planning and implementing oil spill response efforts. This an applied program, and is intended to directly support the MSRC response mission. It does not include studies directly related to damage assessment, which is outside of the mission of MSRC. This paper focuses on the issues MSRC sees as critical in the area of ecological effects research, and addresses four topics: Why do we need to do more? What is it we hope to accomplish? What needs to be done? What is being planned or implemented?

  13. Literature Review on the Effects of Prescription Fire on theEcology of Site 300

    Energy Technology Data Exchange (ETDEWEB)

    Preston, R

    2011-03-14

    Lawrence Livermore National Laboratory has historically conducted prescription burns across approximately 2,000 acres of Site 300 on an annual basis to safeguard test facilities and operations from the risk of wildfire encroachment. Prescription burns began in 1960, and although fire frequency varies among the designated burn areas, all have been burned at least once. A patchwork of native perennial grassland communities and associated special-status plant and animal populations occur onsite in many areas that have been receiving these treatments. Because the size and locations of prescription burns may shift in coming years, an evaluation is warranted to determine how these shifts may affect listed biota, including rare plants, and the distinct ecological conditions present on the site. This report presents the results of a literature review conducted by ICF International (ICF) to collect basic information on native perennial grasslands in California, the influence of fire on these grasslands, and management tools for restoring and maintaining them. The objective of this study was to review the scientific literature on California native grasslands and summarize the current state of knowledge pertaining to the possible effects -- both beneficial and detrimental -- of prescribed fire on the ecology of Site 300. The results of this review are intended to inform future management practices that may be carried out at Site 300 to maintain the plant and wildlife communities and to ensure that the ecological conditions benefit the special-status species that inhabit the Site. This review is also intended to identify a study approach to investigate changes over the next 10 years in the burned areas and in areas where burning will be discontinued.

  14. Effects of shore-level displacement on the ecology of Baltic Sea bays

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Joakim P. [AquaBiota Water Rsearch, Stockholm (Sweden)

    2012-12-15

    This report presents the up to date understanding of changes in ecological structure of small Baltic Sea bays following shore-level displacement and isolation of bays from the sea. It was produced as a part of the biosphere research programme, which has a strong emphasis on the characterization of properties and processes affecting the fate of potentially released radionuclides from the suggested repository of nuclear waste in the bedrock of the Forsmark area. The report has a focus on ecology and gives a description of input data, methodology and results on changes in flora and fauna communities, as well as some abiotic factors, with topographic isolation of bays from the sea. It is intended to describe the properties and conditions at the Forsmark site and to give information essential for demonstrating site specific understanding of processes and properties linked to a sea-to lake succession. Long-term landscape development in the Forsmark area is dependent on two main and partly interdependent factors; shore-level displacement and climate variations. These two factors in combination strongly affect a number of processes, which in turn influence the development of ecosystems. Some examples of such processes are erosion and sedimentation, primary production and decomposition of organic matter. In this work focus has been to report changes in the structure and biomass of flora and fauna communities, which affect primary production, and influence the processes of decomposition of organic matter and sedimentation. A section of the study also deals with the biological processes of primary production, auto trophic carbon uptake and influence of allochtonous energy. The study is part of a description of the Forsmark ecosystem succession during a glacial cycle, which is one of the main objectives of the biosphere modelling at the Swedish Nuclear Fuel and Waste Management Company (SKB). The biomass of macro fauna was found to decrease with increasing isolation of bays

  15. Effects of shore-level displacement on the ecology of Baltic Sea bays

    International Nuclear Information System (INIS)

    Hansen, Joakim P.

    2012-12-01

    This report presents the up to date understanding of changes in ecological structure of small Baltic Sea bays following shore-level displacement and isolation of bays from the sea. It was produced as a part of the biosphere research programme, which has a strong emphasis on the characterization of properties and processes affecting the fate of potentially released radionuclides from the suggested repository of nuclear waste in the bedrock of the Forsmark area. The report has a focus on ecology and gives a description of input data, methodology and results on changes in flora and fauna communities, as well as some abiotic factors, with topographic isolation of bays from the sea. It is intended to describe the properties and conditions at the Forsmark site and to give information essential for demonstrating site specific understanding of processes and properties linked to a sea-to lake succession. Long-term landscape development in the Forsmark area is dependent on two main and partly interdependent factors; shore-level displacement and climate variations. These two factors in combination strongly affect a number of processes, which in turn influence the development of ecosystems. Some examples of such processes are erosion and sedimentation, primary production and decomposition of organic matter. In this work focus has been to report changes in the structure and biomass of flora and fauna communities, which affect primary production, and influence the processes of decomposition of organic matter and sedimentation. A section of the study also deals with the biological processes of primary production, auto trophic carbon uptake and influence of allochtonous energy. The study is part of a description of the Forsmark ecosystem succession during a glacial cycle, which is one of the main objectives of the biosphere modelling at the Swedish Nuclear Fuel and Waste Management Company (SKB). The biomass of macro fauna was found to decrease with increasing isolation of bays

  16. Non-linear effects of drought under shade: reconciling physiological and ecological models in plant communities.

    Science.gov (United States)

    Holmgren, Milena; Gómez-Aparicio, Lorena; Quero, José Luis; Valladares, Fernando

    2012-06-01

    The combined effects of shade and drought on plant performance and the implications for species interactions are highly debated in plant ecology. Empirical evidence for positive and negative effects of shade on the performance of plants under dry conditions supports two contrasting theoretical models about the role of shade under dry conditions: the trade-off and the facilitation hypotheses. We performed a meta-analysis of field and greenhouse studies evaluating the effects of drought at two or more irradiance levels on nine response variables describing plant physiological condition, growth, and survival. We explored differences in plant response across plant functional types, ecosystem types and methodological approaches. The data were best fit using quadratic models indicating a humped-back shape response to drought along an irradiance gradient for survival, whole plant biomass, maximum photosynthetic capacity, stomatal conductance and maximal photochemical efficiency. Drought effects were ameliorated at intermediate irradiance, becoming more severe at higher or lower light levels. This general pattern was maintained when controlling for potential variations in the strength of the drought treatment among light levels. Our quantitative meta-analysis indicates that dense shade ameliorates drought especially among drought-intolerant and shade-tolerant species. Wet tropical species showed larger negative effects of drought with increasing irradiance than semiarid and cold temperate species. Non-linear responses to irradiance were stronger under field conditions than under controlled greenhouse conditions. Non-linear responses to drought along the irradiance gradient reconciliate opposing views in plant ecology, indicating that facilitation is more likely within certain range of environmental conditions, fading under deep shade, especially for drought-tolerant species.

  17. The genetics of indirect ecological effects - plant parasites and aphid herbivores

    Directory of Open Access Journals (Sweden)

    Jennifer K Rowntree

    2014-04-01

    Full Text Available When parasitic plants and aphid herbivores share a host, both direct and indirect ecological effects (IEEs can influence evolutionary processes. We used a hemiparasitic plant (Rhinanthus minor, a grass host (Hordeum vulgare and a cereal aphid (Sitobion avenae to investigate the genetics of IEEs between the aphid and the parasitic plant, and looked to see how these might affect or be influenced by the genetic diversity of the host plants. Survival of R. minor depended on the parasite’s population of origin, the genotypes of the aphids sharing the host and the genetic diversity in the host plant community. Hence the indirect effects of the aphids on the parasitic plants depended on the genetic environment of the system. Here, we show that genetic variation can be important in determining the outcome of IEEs. Therefore, IEEs have the potential to influence evolutionary processes and the continuity of species interactions over time.

  18. The radioiodine problem following the Chernobyl accident: ecology, dosimetry and medical effects

    International Nuclear Information System (INIS)

    Zvonova, I.A.

    1991-01-01

    Following the Chernobyl accident radioisotopes of iodine constituted the main dose-forming factor among the people who stayed on in the radioactively contaminated areas, and in a number of places the effective doses to the thyroid gland were up to two orders of magnitude higher than the whole-body dose stemming from uniform internal and external irradiation. We consider the mechanisms involved in the radioiodine contribution to the doses in the human organism, depending on intake path, life style and social and ecological factors. We illustrate, by means of examples, thyroid gland dose distribution for various age groups in the population, and discuss the medical effects and predict the long-term risks for the population of exposure to radioisotopes of iodine. (author)

  19. Ecological Effects in Cross-Cultural Differences Between U.S. and Japanese Color Preferences.

    Science.gov (United States)

    Yokosawa, Kazuhiko; Schloss, Karen B; Asano, Michiko; Palmer, Stephen E

    2016-09-01

    We investigated cultural differences between U.S. and Japanese color preferences and the ecological factors that might influence them. Japanese and U.S. color preferences have both similarities (e.g., peaks around blue, troughs around dark-yellow, and preferences for saturated colors) and differences (Japanese participants like darker colors less than U.S. participants do). Complex gender differences were also evident that did not conform to previously reported effects. Palmer and Schloss's (2010) weighted affective valence estimate (WAVE) procedure was used to test the Ecological Valence Theory's (EVT's) prediction that within-culture WAVE-preference correlations should be higher than between-culture WAVE-preference correlations. The results supported several, but not all, predictions. In the second experiment, we tested color preferences of Japanese-U.S. multicultural participants who could read and speak both Japanese and English. Multicultural color preferences were intermediate between U.S. and Japanese preferences, consistent with the hypothesis that culturally specific personal experiences during one's lifetime influence color preferences. Copyright © 2015 Cognitive Science Society, Inc.

  20. Effects of selenium accumulation on phytotoxicity, herbivory, and pollination ecology in radish (Raphanus sativus L.)

    International Nuclear Information System (INIS)

    Hladun, Kristen R.; Parker, David R.; Tran, Khoa D.; Trumble, John T.

    2013-01-01

    Selenium (Se) has contaminated areas in the western USA where pollination is critical to the functioning of both agricultural and natural ecosystems, yet we know little about how Se can impact pollinators. In a two-year semi-field study, the weedy plant Raphanus sativus (radish) was exposed to three selenate treatments and two pollination treatments to evaluate the effects on pollinator–plant interactions. Honey bee (Apis mellifera L.) pollinators were observed to readily forage on R. sativus for both pollen and nectar despite high floral Se concentrations. Se treatment increased both seed abortion (14%) and decreased plant biomass (8–9%). Herbivory by birds and aphids was reduced on Se-treated plants, indicating a potential reproductive advantage for the plant. Our study sheds light on how pollutants such as Se can impact the pollination ecology of a plant that accumulates even moderate amounts of Se. - Highlights: ► Radish were exposed to selenate and pollination treatments to examine pollination ecology. ► Honey bees foraged on radish for both pollen and nectar despite high floral Se concentrations. ► Se treatment increased seed abortion and decreased plant biomass. ► Herbivory by birds and aphids was reduced in Se-treated plants. ► Pollutants such as Se can impact the pollination of a plant that accumulates even moderate amounts. - Radish accumulated the pollutant selenium in floral tissues, but this did not deter the pollinator (Apis mellifera) from foraging.

  1. Fast Growing Plantations for Wood Production - Integration of Ecological Effects and Economic Perspectives.

    Science.gov (United States)

    Bredemeier, Michael; Busch, Gerald; Hartmann, Linda; Jansen, Martin; Richter, Falk; Lamersdorf, Norbert P

    2015-01-01

    Biomass crops are perceived as a feasible means to substitute sizeable amounts of fossil fuel in the future. A prospect of CO2 reduction (resp. CO2 neutrality) is credited to biomass fuels, and thus a potential contribution to mitigate climate change. Short rotation coppices (SRCs) with fast growing poplar and willow trees are an option for producing high yields of woody biomass, which is suitable for both energetic and material use. One negative effect that comes along with the establishment of SRC may be a decrease in groundwater recharge, because high rates of transpiration and interception are anticipated. Therefore, it is important to measure, analyze, and model the effects of SRC-planting on landscape water budgets. To analyze the effects on the water budget, a poplar SRC plot was studied by measuring hydrological parameters to be used in the hydrological model WaSim. Results reveal very low or even missing ground water recharge for SRC compared to agricultural land use or grassland, especially succeeding dry years. However, this strong effect on plot level is moderated on the larger spatial scale of catchment level, for which the modeling was also performed. In addition to water, nutrient fluxes and budgets were studied. Nitrogen is still a crucial issue in today's agriculture. Intensive fertilization or increased applications of manure from concentrated livestock breeding are often leading to high loads of nitrate leaching, or enhanced N2O emissions to the atmosphere on arable crop fields. SRC or agroforestry systems on former crop land may offer an option to decrease such N losses, while simultaneously producing woody biomass. This is mainly due to the generally smaller N requirements of woody vegetation, which usually entail no need for any fertilization. The trees supply deep and permanent rooting systems, which can be regarded as a "safety net" to prevent nutrient leaching. Thus, SRC altogether can help to diminish N eutrophication. It is important to

  2. Ecologically relevant levels of multiple, common marine stressors suggest antagonistic effects.

    Science.gov (United States)

    Lange, Rolanda; Marshall, Dustin

    2017-07-24

    Stressors associated with global change will be experienced simultaneously and may act synergistically, so attempts to estimate the capacity of marine systems to cope with global change requires a multi-stressor approach. Because recent evidence suggests that stressor effects can be context-dependent, estimates of how stressors are experienced in ecologically realistic settings will be particularly valuable. To enhance our understanding of the interplay between environmental effects and the impact of multiple stressors from both natural and anthropogenic sources, we conducted a field experiment. We explored the impact of multiple, functionally varied stressors from both natural and anthropogenic sources experienced during early life history in a common sessile marine invertebrate, Bugula neritina. Natural spatial environmental variation induced differences in conspecific densities, allowing us to test for density-driven context-dependence of stressor effects. We indeed found density-dependent effects. Under high conspecific density, individual survival increased, which offset part of the negative effects of experiencing stressors. Experiencing multiple stressors early in life history translated to a decreased survival in the field, albeit the effects were not as drastic as we expected: our results are congruent with antagonistic stressor effects. We speculate that when individual stressors are more subtle, stressor synergies become less common.

  3. Scale dependency in effectiveness, isolation, and social-ecological spillover of protected areas.

    Science.gov (United States)

    Ament, Judith M; Cumming, Graeme S

    2016-08-01

    Protected areas are considered vital for the conservation of biodiversity. Given their central role in many conservation strategies, it is important to know whether they adequately protect biodiversity within their boundaries; whether they are becoming more isolated from other natural areas over time; and whether they play a role in facilitating or reducing land-cover change in their surroundings. We used matching methods and national and local analyses of land-cover change to evaluate the combined effectiveness (i.e., avoided natural-cover loss), isolation (i.e., changes in adjacent areas), and spillover effects (i.e., impacts on adjacent areas) of 19 national parks in South Africa from 2000 to 2009. All parks had either similar or lower rates of natural-cover loss than matched control samples. On a national level, mean net loss of natural cover and mean net gain of cultivation cover decreased with distance from park boundary, but there was considerable variation in trends around individual parks, providing evidence for both increased isolation and buffering of protected areas. Fourteen parks had significant positive spillover and reduced natural-cover loss in their surroundings, whereas five parks experienced elevated levels of natural-cover loss. Conclusions about social-ecological spillover effects from protected areas depended heavily on the measures of land-cover change used and the scale at which the results were aggregated. Our findings emphasize the need for high-resolution data when assessing spatially explicit phenomena such as land-cover change and challenge the usefulness of large-scale (coarse grain, broad extent) studies for understanding social-ecological dynamics around protected areas. © 2016 Society for Conservation Biology.

  4. Ecological and biomedical effects of effluents from near-term electric vehicle storage battery cycles

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-01

    An assessment of the ecological and biomedical effects due to commercialization of storage batteries for electric and hybrid vehicles is given. It deals only with the near-term batteries, namely Pb/acid, Ni/Zn, and Ni/Fe, but the complete battery cycle is considered, i.e., mining and milling of raw materials, manufacture of the batteries, cases and covers; use of the batteries in electric vehicles, including the charge-discharge cycles; recycling of spent batteries; and disposal of nonrecyclable components. The gaseous, liquid, and solid emissions from various phases of the battery cycle are identified. The effluent dispersal in the environment is modeled and ecological effects are assessed in terms of biogeochemical cycles. The metabolic and toxic responses by humans and laboratory animals to constituents of the effluents are discussed. Pertinent environmental and health regulations related to the battery industry are summarized and regulatory implications for large-scale storage battery commercialization are discussed. Each of the seven sections were abstracted and indexed individually for EDB/ERA. Additional information is presented in the seven appendixes entitled; growth rate scenario for lead/acid battery development; changes in battery composition during discharge; dispersion of stack and fugitive emissions from battery-related operations; methodology for estimating population exposure to total suspended particulates and SO/sub 2/ resulting from central power station emissions for the daily battery charging demand of 10,000 electric vehicles; determination of As air emissions from Zn smelting; health effects: research related to EV battery technologies. (JGB)

  5. Applying adverse outcome pathways and species sensitivity-weighted distribution to predicted-no-effect concentration derivation and quantitative ecological risk assessment for bisphenol A and 4-nonylphenol in aquatic environments: A case study on Tianjin City, China.

    Science.gov (United States)

    Wang, Ying; Na, Guangshui; Zong, Humin; Ma, Xindong; Yang, Xianhai; Mu, Jingli; Wang, Lijun; Lin, Zhongsheng; Zhang, Zhifeng; Wang, Juying; Zhao, Jinsong

    2018-02-01

    Adverse outcome pathways (AOPs) are a novel concept that effectively considers the toxic modes of action and guides the ecological risk assessment of chemicals. To better use toxicity data including biochemical or molecular responses and mechanistic data, we further developed a species sensitivity-weighted distribution (SSWD) method for bisphenol A and 4-nonylphenol. Their aquatic predicted-no-effect concentrations (PNECs) were derived using the log-normal statistical extrapolation method. We calculated aquatic PNECs of bisphenol A and 4-nonylphenol with values of 4.01 and 0.721 µg/L, respectively. The ecological risk of each chemical in different aquatic environments near Tianjin, China, a coastal municipality along the Bohai Sea, was characterized by hazard quotient and probabilistic risk quotient assessment techniques. Hazard quotients of 7.02 and 5.99 at 2 municipal sewage sites using all of the endpoints were observed for 4-nonylphenol, which indicated high ecological risks posed by 4-nonylphenol to aquatic organisms, especially endocrine-disrupting effects. Moreover, a high ecological risk of 4-nonylphenol was indicated based on the probabilistic risk quotient method. The present results show that combining the SSWD method and the AOP concept could better protect aquatic organisms from adverse effects such as endocrine disruption and could decrease uncertainty in ecological risk assessment. Environ Toxicol Chem 2018;37:551-562. © 2017 SETAC. © 2017 SETAC.

  6. Transient Social-Ecological Stability: the Effects of Invasive Species and Ecosystem Restoration on Nutrient Management Compromise in Lake Erie

    Directory of Open Access Journals (Sweden)

    Eric D. Roy

    2010-03-01

    Full Text Available Together, lake ecosystems and local human activity form complex social-ecological systems (SESs characterized by feedback loops and discontinuous change. Researchers in diverse fields have suggested that complex systems do not have single stable equilibria in the long term because of inevitable perturbation. During this study, we sought to address the general question of whether or not stable social-ecological equilibria exist in highly stressed and managed lacustrine systems. Using an integrated human-biophysical model, we investigated the impacts of a species invasion and ecosystem restoration on SES equilibrium, defined here as a compromise in phosphorus management among opposing stakeholders, in western Lake Erie. Our integrated model is composed of a calibrated ecological submodel representing Sandusky Bay, and a phosphorus management submodel that reflects the societal benefits and costs of phosphorus regulation. These two submodels together form a dynamic feedback loop that includes freshwater ecology, ecosystem services, and phosphorus management. We found that the invasion of dreissenid mussels decreased ecosystem resistance to eutrophication, necessitating increased phosphorus management to preserve ecosystem services and thus creating the potential for a shift in social-ecological equilibrium. Additionally, our results suggest that net benefits in the region following the invasion of dreissenids may never again reach the pre-invasion level if on-site phosphorus control is the sole management lever. Further demonstrating transient system stability, large-scale wetland restoration shifted points of management compromise to states characterized by less on-site phosphorus management and higher environmental quality, resulting in a significant increase in net benefits in the region. We conclude that lacustrine SESs are open and dynamic, and we recommend that future models of these systems emphasize site-specific perturbation over

  7. Effects of selenium accumulation on phytotoxicity, herbivory, and pollination ecology in radish (Raphanus sativus L.).

    Science.gov (United States)

    Hladun, Kristen R; Parker, David R; Tran, Khoa D; Trumble, John T

    2013-01-01

    Selenium (Se) has contaminated areas in the western USA where pollination is critical to the functioning of both agricultural and natural ecosystems, yet we know little about how Se can impact pollinators. In a two-year semi-field study, the weedy plant Raphanus sativus (radish) was exposed to three selenate treatments and two pollination treatments to evaluate the effects on pollinator-plant interactions. Honey bee (Apis mellifera L.) pollinators were observed to readily forage on R. sativus for both pollen and nectar despite high floral Se concentrations. Se treatment increased both seed abortion (14%) and decreased plant biomass (8-9%). Herbivory by birds and aphids was reduced on Se-treated plants, indicating a potential reproductive advantage for the plant. Our study sheds light on how pollutants such as Se can impact the pollination ecology of a plant that accumulates even moderate amounts of Se. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. The ecological effect of unemployment on the incidence of very low birthweight in Norway and Sweden.

    Science.gov (United States)

    Catalano, R; Hansen, H T; Hartig, T

    1999-12-01

    Little attention has been paid to the ecological effects of unemployment, despite strong theory suggesting that being socially or economically connected to unemployed persons can induce illness. Theory suggests, for example, that the labor market experience of adult males should affect maternal and infant health. We advance this line of inquiry by testing the hypothesis that quarterly increases in unemployment among Norwegian and Swedish males were associated with increased incidence of very low weight births from 1973 through 1995. Results support the hypothesis. We estimate that approximately 188 very low weight births could have been averted in Norway, and about 329 in Sweden, if quarterly increases in male unemployment had been constrained to the median over the 23-year period. Our findings imply that the social cost of unemployment may be underestimated by focusing on unemployment as an individual risk factor.

  9. Studies of effects of closed microbial ecology. Report of 180-day test period

    Science.gov (United States)

    Kenyon, A. J.

    1972-01-01

    Experiments were performed to determine the influence closed microbial ecologies have on modification or simplification of natural intestinal flora of ferrets in a closed environmental system. On the basis of previous tests in which certain species (Salmonella and Bacteroides) were decreased at 90 days of enclosure, a second trial was constructed for 180-day tests. In this trial there was little difference in the 8 major classes of intestinal flora between animals in the Open and Closed environmental groups except for the level of Lactobacillus. It is of extreme importance to note that when both Open and Closed groups contracted hemorrhagic gastritis, the interrelationship of this agent with other intestinal flora produced a more profound effect on animals from the Closed Group, particularly with reference to Lactobacillus levels.

  10. Potential Ecological Effects of Contaminants in the Exposed Par Pond Sediments

    International Nuclear Information System (INIS)

    Paller, M.H.; Wike, L.D.

    1996-08-01

    Sediment and small mammal samples were collected from the exposed sediments of Par Pond in early 1995, shortly before the reservoir was refilled after a 4-year drawdown. Sampling was confined to elevations between 58 and 61 meters (190 and 200 feet) above mean sea level, which includes the sediments likely to be exposed if the Par Pond water level is permitted to fluctuate naturally. Both soil and small mammal samples were analyzed for a number of radionuclides and metals. Some of the soil samples were also analyzed for organic contaminants. The objective of the study was to determine if contaminant levels in the Par Pond sediments were high enough to cause deleterious ecological effects

  11. Effects of simulated acid rain on soil fauna community composition and their ecological niches.

    Science.gov (United States)

    Wei, Hui; Liu, Wen; Zhang, Jiaen; Qin, Zhong

    2017-01-01

    Acid rain is one of the severest environmental issues globally. Relative to other global changes (e.g., warming, elevated atmospheric [CO 2 ], and nitrogen deposition), however, acid rain has received less attention than its due. Soil fauna play important roles in multiple ecological processes, but how soil fauna community responds to acid rain remains less studied. This microcosm experiment was conducted using latosol with simulated acid rain (SAR) manipulations to observe potential changes in soil fauna community under acid rain stress. Four pH levels, i.e., pH 2.5, 3.5, 4.5, and 5.5, and a neutral control of pH 7.0 were set according to the current pH condition and acidification trend of precipitation in southern China. As expected, we observed that the SAR treatments induced changes in soil fauna community composition and their ecological niches in the tested soil; the treatment effects tended to increase as acidity increased. This could be attributable to the environmental stresses (such as acidity, porosity and oxygen supply) induced by the SAR treatments. In addition to direct acidity effect, we propose that potential changes in permeability and movability of water and oxygen in soils induced by acid rain could also give rise to the observed shifts in soil fauna community composition. These are most likely indirect pathways of acid rain to affect belowground community. Moreover, we found that nematodes, the dominating soil fauna group in this study, moved downwards to mitigate the stress of acid rain. This is probably detrimental to soil fauna in the long term, due to the relatively severer soil conditions in the deep than surface soil layer. Our results suggest that acid rain could change soil fauna community and the vertical distribution of soil fauna groups, consequently changing the underground ecosystem functions such as organic matter decomposition and greenhouse gas emissions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Analysis of ecological effects of geopressured-geothermal resource development. Geopressured-geothermal technical paper No. 4

    Energy Technology Data Exchange (ETDEWEB)

    1979-07-01

    The activities involved in geopressured-geothermal resource production are identified and their ecological impacts are discussed. The analysis separates those activites that are unique to geopressured-geothermal development from those that also occur in oil and gas and other resource developments. Of the unique activities, those with the greatest potential for serious ecological effect are: (1) accidental brine discharge as a result of a blowout during well drilling; (2) subsidence; (3) fault activation and enhanced seismicity; and (4) subsurface contamination of water, hydrocarbon, and mineral reservoirs. Available methods to predict and control these effects are discussed.

  13. Characterizing CDMA downlink feasibility via effective interference

    NARCIS (Netherlands)

    Endrayanto, A.I.; van den Berg, Hans Leo; Boucherie, Richardus J.

    2003-01-01

    This paper models and analyses downlink power assignment feasibility in Code Division Multiple Access (CDMA) mobile networks. By discretizing the area into small segments, the power requirements are characterized via a matrix representation that separates user and system characteristics. We obtain a

  14. Ecological crisis: The 'Chernobyl feeling' - or how the mental effects of the ecological disaster can be detected and 'measured'

    International Nuclear Information System (INIS)

    Boehm, A.; Boehnke, K.; Boldt, P.R.; Faas, A.; Gross, B.; Jaeggi, E.; Legewie, H.

    1989-01-01

    Given real personal embarrassment, the Chernobyl accident indeed has had an impact on the vital consciousness, and this effect has been developing in two phases, an initial phase, and a subsequent phase characterised by mental digestion. In the initial, post-accident phase, the typical 'Chernobyl feeling' is frequently predominant. If this feeling later is weakened or diluted by a back-to-normal attitude, no bearing effects on vital consciousness or identity feeling can be observed, but a general feeling of pessimism and resignment remains. If, however, 'normalisation' did not set in until the first interview in this study, personal identity is found to be undergoing a change. A more conscious apprehension of life can be observed, a change in life style up to political commitment, or also leading to a determined turn to short-term, private compensating activities, (last-minute panic). (orig./HP) [de

  15. Extensive geographic and ontogenetic variation characterizes the trophic ecology of a temperate reef fish on southern California (USA) rocky reefs

    Science.gov (United States)

    Hamilton, Scott L.; Caselle, Jennifer E.; Lantz, Coulson A.; Egloff, Tiana L.; Kondo, Emi; Newsome, Seth D.; Loke-Smith, Kerri; Pondella, Daniel J.; Young, Kelly A.; Lowe, Christopher G.

    2015-01-01

    Interactions between predator and prey act to shape the structure of ecological communities, and these interactions can differ across space. California sheephead Semicossyphus pulcher are common predators of benthic invertebrates in kelp beds and rocky reefs in southern California, USA. Through gut content and stable isotope (δ13C and †15N) analyses, we investigated geographic and ontogenetic variation in trophic ecology across 9 populations located at island and mainland sites throughout southern California. We found extensive geographic variation in California sheephead diet composition over small spatial scales. Populations differed in the proportion of sessile filter/suspension feeders or mobile invertebrates in the diet. Spatial variation in diet was highly correlated with other life history and demographic traits (e.g. growth, survivorship, reproductive condition, and energy storage), in addition to proxies of prey availability from community surveys. Multivariate descriptions of the diet from gut contents roughly agreed with the spatial groupings of sites based on stable isotope analysis of both California sheephead and their prey. Ontogenetic changes in diet occurred consistently across populations, despite spatial differences in size structure. As California sheephead increase in size, diets shift from small filter feeders, like bivalves, to larger mobile invertebrates, such as sea urchins. Our results indicate that locations with large California sheephead present, such as many marine reserves, may experience increased predation pressure on sea urchins, which could ultimately affect kelp persistence. PMID:26246648

  16. [Ecological Effects of Algae Blooms Cluster: The Impact on Chlorophyll and Photosynthesis of the Water Hyacinth].

    Science.gov (United States)

    Liu, Guo-feng; He, Jun; Yang, Yi-zhong; Han, Shi-qun

    2015-08-01

    The response of chlorophyll and photosynthesis of water hyacinth leaves in different concentrations of clustered algae cells was studied in the simulation experiment, and the aim was to reveal the mechanism of the death of aquatic plants during algae blooms occurred through studying the physiological changes of the macrophytes, so as to play the full function of the ecological restoration of the plants. And results showed the dissolved oxygen quickly consumed in root zone of aquatic plants after algae blooms gathered and showed the lack of oxygen (DO algae cell died and concentration of DTN in treatment 1 and 2 were 44.49 mg x L(-1) and 111.32 mg x L(-1), and the content of DTP were 2.57 mg x L(-1) and 9.10 mg x L(-1), respectively. The NH4+ -N concentrations were as high as 32.99 mg x L(-1) and 51.22 mg x L(-1), and the root zone with the anoxia, strong reducing, higher nutrients environment had a serious stress effects to the aquatic plants. The macrophytes photosynthesis reduced quickly and the plant body damaged with the intimidation of higher NH4+ -N concentration (average content was 45.6 mg x L(-1)) and hypoxia after algae cell decomposed. The average net photosynthesis rate, leaf transpiration rate of the treatment 2 reduced to 3.95 micromol (M2 x S)(-1), 0.088 micromol x (m2 x s)(-1), and only were 0.18 times, 0.11 times of the control group, respectively, at the end of the experiment, the control group were 22 micromol x (m2 x s)(-1), 0.78 micromol x (M2 x s)(-1). Results indicated the algae bloom together had the irreversible damage to the aquatic plants. Also it was found large amounts of new roots and the old roots were dead in the treatment 1, but roots were all died in the treatment 2, and leaves were yellow and withered. Experiment results manifested that the serious environment caused by the algae blooms together was the main reason of the death of aquatic plants during the summer. So in the practice of ecological restoration, it should avoid the

  17. Ecological effects and animal risk assessment of radiation pollution in Russia and former USSR

    International Nuclear Information System (INIS)

    Krivolutsky, D.

    1995-01-01

    The ecological after-effects of long-term radiation pollution, animal biodiversity changes and life-cycle assessment of model species of soil invertebrates mammals, birds, reptiles have been studied in 1968-1994 in the former USSR (Russia, Ukraine, Kazachstan). There has been observed an initial reduction of animal biodiversity community structure in Kyshtym (south Ural) and Chernobyl polluted areas and a low return to the former ecosystems. The secondary changes and side-effects for the active migrants (insects, birds, mammals) have been registered. The most valid bioindicators and biomarkers of radioactive pollution may be stable populations of reptiles, birds, earthworms, centipede, microarthropods. The radioactive soil pollution exerts the greatest impact on the permanent soil dwelling animals. As direct effects it has been seen the appreciable reduction of population density disturbance of the breeding process, degradation of species diversity community structure. In fact a soil with high level 90 Sr and a radiation 1--3 R/day containing 10-fold reduction of population soil inhabit millipedes earthworms, insect larvae, Enchytraeidae aranea. The accumulation of radionuclides by terrestrial and soil animals effects of trophic levels, zoogenical radionuclides migration have been studied in polluted ecosystems of South Ural and Chernobyl

  18. Differential effects of ephemeral colonization by arbuscular mycorrhizal fungi in two Cuscuta species with different ecology.

    Science.gov (United States)

    Behdarvandi, Behrang; Guinel, Frédérique C; Costea, Mihai

    2015-10-01

    Seedlings of parasitic Cuscuta species are autotrophic but can survive only a short period of time, during which they must locate and attach to a suitable host. They have an ephemeral root-like organ considered not a "true" root by most studies. In the present study, two species with contrasting ecology were examined: Cuscuta gronovii, a North American riparian species, and Cuscuta campestris, an invasive dodder that thrives in disturbed habitats. The morphology, structure, and absorptive capability of their root-like organ were compared, their potential for colonization by two species of arbuscular mycorrhizal fungi (AMF) was assessed, and the effect of the AMF on seedling growth and survival was determined. The root of both species absorbed water and interacted with AMF, but the two species exhibited dissimilar growth and survival patterns depending on the colonization level of their seedlings. The extensively colonized seedlings of C. gronovii grew more and survived longer than non-colonized seedlings. In contrast, the scarce colonization of C. campestris seedlings did not increase their growth or longevity. The differential growth responses of the AMF-colonized and non-colonized Cuscuta species suggest a mycorrhizal relationship and reflect their ecology. While C. gronovii roots have retained a higher ability to interact with AMF and are likely to take advantage of fungal communities in riparian habitats, the invasive C. campestris has largely lost this ability possibly as an adaptation to disturbed ecosystems. These results indicate that dodders have a true root, even if much reduced and ephemeral, that can interact with AMF.

  19. Effect of hypoxia and anoxia on invertebrate behaviour: ecological perspectives from species to community level

    Science.gov (United States)

    Riedel, B.; Pados, T.; Pretterebner, K.; Schiemer, L.; Steckbauer, A.; Haselmair, A.; Zuschin, M.; Stachowitsch, M.

    2014-03-01

    Coastal hypoxia and anoxia have become a global key stressor to marine ecosystems, with almost 500 dead zones recorded worldwide. By triggering cascading effects from the individual organism to the community- and ecosystem level, oxygen depletions threaten marine biodiversity and can alter ecosystem structure and function. By integrating both physiological function and ecological processes, animal behaviour is ideal for assessing the stress state of benthic macrofauna to low dissolved oxygen. The initial response of organisms can serve as an early warning signal, while the successive behavioural reactions of key species indicate hypoxia levels and help assess community degradation. Here we document the behavioural responses of a representative spectrum of benthic macrofauna in the natural setting in the Northern Adriatic Sea (Mediterranean). We experimentally induced small-scale anoxia with a benthic chamber in 24 m depth to overcome the difficulties in predicting the onset of hypoxia, which often hinders full documentation in the field. The behavioural reactions were documented with a time-lapse camera. Oxygen depletion elicited significant and repeatable changes in general (visibility, locomotion, body movement and posture, location) and species-specific reactions in virtually all organisms (302 individuals from 32 species and 2 species groups). Most atypical (stress) behaviours were associated with specific oxygen thresholds: arm-tipping in the ophiuroid Ophiothrix quinquemaculata, for example, with the onset of mild hypoxia (behaviour, and predator-prey interactions and relationships shifted. This nuanced scale of resolution is a useful tool to interpret present benthic community status (behaviour) and past mortalities (community composition, e.g. survival of tolerant species). This information on the sensitivity (onset of stress response), tolerance (mortality, survival), and characteristics (i.e. life habit, functional role) of key species also helps predict

  20. Structuring a cost-effective site characterization

    International Nuclear Information System (INIS)

    Berven, B.A.; Little, C.A.; Swaja, R.E.

    1990-01-01

    Successful chemical and radiological site characterizations are complex activities which require meticulously detailed planning. Each layer of investigation is based upon previously generated information about the site. Baseline historical, physical, geological, and regulatory information is prerequisite for preliminary studies at a site. Preliminary studies then provide samples and measurements which define the identity of potential contaminants and define boundaries around the area to be investigated. The goal of a full site characterization is to accurately determine the extent and magnitude of contaminants and carefully define the site conditions such that the future movements of site contaminants can be assessed for potential exposure to human occupants and/or environmental impacts. Critical to this process is the selection of appropriate measurement and sampling methodology, selection and use of appropriate instrumentation and management/interpretation of site information. Site investigations require optimization between the need of information to maximize the understanding of site conditions and the cost of acquiring that information. 5 refs., 1 tab

  1. Thermal Characterization of a Hall Effect Thruster

    Science.gov (United States)

    2008-03-01

    View Factor A = Area θ = Angle R = Distance xiii J = Radiosity q = Heat Transfer Rate W = Radiated Power U = Voltage C...summation rule. 1 1 N ij j F = =∑ (18) Radiosity (Ji) takes into account both radiation emitted and reflected from a surface. Analyzing radiation...exchanges between two surfaces is made easier with a few assumptions. Each surface is assumed isothermal and characterized by a uniform radiosity

  2. Linking removal targets to the ecological effects of invaders: a predictive model and field test.

    Science.gov (United States)

    Green, Stephanie J; Dulvy, Nicholas K; Brooks, Annabelle M L; Akins, John L; Cooper, Andrew B; Miller, Skylar; Côté, Isabelle M

    Species invasions have a range of negative effects on recipient ecosystems, and many occur at a scale and magnitude that preclude complete eradication. When complete extirpation is unlikely with available management resources, an effective strategy may be to suppress invasive populations below levels predicted to cause undesirable ecological change. We illustrated this approach by developing and testing targets for the control of invasive Indo-Pacific lionfish (Pterois volitans and P. miles) on Western Atlantic coral reefs. We first developed a size-structured simulation model of predation by lionfish on native fish communities, which we used to predict threshold densities of lionfish beyond which native fish biomass should decline. We then tested our predictions by experimentally manipulating lionfish densities above or below reef-specific thresholds, and monitoring the consequences for native fish populations on 24 Bahamian patch reefs over 18 months. We found that reducing lionfish below predicted threshold densities effectively protected native fish community biomass from predation-induced declines. Reductions in density of 25–92%, depending on the reef, were required to suppress lionfish below levels predicted to overconsume prey. On reefs where lionfish were kept below threshold densities, native prey fish biomass increased by 50–70%. Gains in small (15 cm total length), including ecologically important grazers and economically important fisheries species, had increased by 10–65% by the end of the experiment. Crucially, similar gains in prey fish biomass were realized on reefs subjected to partial and full removal of lionfish, but partial removals took 30% less time to implement. By contrast, the biomass of small native fishes declined by >50% on all reefs with lionfish densities exceeding reef-specific thresholds. Large inter-reef variation in the biomass of prey fishes at the outset of the study, which influences the threshold density of lionfish

  3. Effects of the antibiotic enrofloxacin on the ecology of tropical eutrophic freshwater microcosms.

    Science.gov (United States)

    Rico, Andreu; Dimitrov, Mauricio R; Van Wijngaarden, René P A; Satapornvanit, Kriengkrai; Smidt, Hauke; Van den Brink, Paul J

    2014-02-01

    The main objective of the present study was to assess the ecological impacts of the fluoroquinolone antibiotic enrofloxacin on the structure and functioning of tropical freshwater ecosystems. Enrofloxacin was applied at a concentration of 1, 10, 100 and 1,000 μg/L for 7 consecutive days in 600-L outdoor microcosms in Thailand. The ecosystem-level effects of enrofloxacin were monitored on five structural (macroinvertebrates, zooplankton, phytoplankton, periphyton and bacteria) and two functional (organic matter decomposition and nitrogen cycling) endpoint groups for 4 weeks after the last antibiotic application. Enrofloxacin was found to dissipate relatively fast from the water column (half-dissipation time: 11.7h), and about 11% of the applied dose was transformed into its main by-product ciprofloxacin after 24h. Consistent treatment-related effects on the invertebrate and primary producer communities and on organic matter decomposition could not be demonstrated. Enrofloxacin significantly affected the structure of leaf-associated bacterial communities at the highest treatment level, and reduced the abundance of ammonia-oxidizing bacteria and ammonia-oxidizing archaea in the sediments, with calculated NOECs of 10 and enrofloxacin are not likely to result in direct or indirect toxic effects on the invertebrate and primary producer communities, nor on important microbially mediated functions such as nitrification. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Ecological contingency in the effects of climatic warming on forest herb communities

    Science.gov (United States)

    Harrison, Susan; Damschen, Ellen Ingman; Grace, James B.

    2010-01-01

    Downscaling from the predictions of general climate models is critical to current strategies for mitigating species loss caused by climate change. A key impediment to this downscaling is that we lack a fully developed understanding of how variation in physical, biological, or land-use characteristics mediates the effects of climate change on ecological communities within regions. We analyzed change in understory herb communities over a 60-y period (1949/1951–2007/2009) in a complex montane landscape (the Siskiyou Mountains, Oregon) where mean temperatures have increased 2 °C since 1948, similar to projections for other terrestrial communities. Our 185 sites included primary and secondary-growth lower montane forests (500–1.200 m above sea level) and primary upper montane to subalpine forests (1,500–2,100 m above sea level). In lower montane forests, regardless of land-use history, we found multiple herb-community changes consistent with an effectively drier climate, including lower mean specific leaf area, lower relative cover by species of northern biogeographic affinity, and greater compositional resemblance to communities in southerly topographic positions. At higher elevations we found qualitatively different and more modest changes, including increases in herbs of northern biogeographic affinity and in forest canopy cover. Our results provide community-level validation of predicted nonlinearities in climate change effects.

  5. Ecological analysis of the health effects of income inequality in Argentina.

    Science.gov (United States)

    De Maio, Fernando G

    2008-05-01

    Despite a large body of empirical literature, a consensus has not been reached concerning the health effects of income inequality. This study contributes to ongoing debates by examining the robustness of the income inequality-population health relationship in Argentina, using five different income inequality indexes (each sensitive to inequalities in differing parts of the income spectrum) and five measures of population health. Cross-sectional, ecological study. Income and self-reported morbidity data from Argentina's 2001 Encuesta de Condiciones de Vida (Survey of living conditions) were analysed at the provincial level. Provincial rates of male/female life expectancy and infant mortality were drawn from the Instituto Nacional de Estadistica y Censos database. Life expectancy was correlated in the expected direction with provincial-level income inequality (operationalized as the Gini coefficient) for both males (r=-0.55, P<0.01) and females (r=-0.61, P<0.01), but this association was not robust for all five income inequality indexes. In contrast, infant mortality, self-reported poor health and self-reported activity limitation were not correlated with any of the income inequality indexes. This study adds further complexity to the literature on the health effects of income inequality by highlighting the important effects of operational definitions. Mortality and morbidity data cannot be used as reasonably interchangeable variables (a common practice in this literature), and the choice of income inequality indicator may influence the results.

  6. Plant species effects on soil nutrients and chemistry in arid ecological zones.

    Science.gov (United States)

    Johnson, Brittany G; Verburg, Paul S J; Arnone, John A

    2016-09-01

    The presence of vegetation strongly influences ecosystem function by controlling the distribution and transformation of nutrients across the landscape. The magnitude of vegetation effects on soil chemistry is largely dependent on the plant species and the background soil chemical properties of the site, but has not been well quantified along vegetation transects in the Great Basin. We studied the effects of plant canopy cover on soil chemistry within five different ecological zones, subalpine, montane, pinyon-juniper, sage/Mojave transition, and desert shrub, in the Great Basin of Nevada all with similar underlying geology. Although plant species differed in their effects on soil chemistry, the desert shrubs Sarcobatus vermiculatus, Atriplex spp., Coleogyne ramosissima, and Larrea tridentata typically exerted the most influence on soil chemistry, especially amounts of K(+) and total nitrogen, beneath their canopies. However, the extent to which vegetation affected soil nutrient status in any given location was not only highly dependent on the species present, and presumably the nutrient requirements and cycling patterns of the plant species, but also on the background soil characteristics (e.g., parent material, weathering rates, leaching) where plant species occurred. The results of this study indicate that the presence or absence of a plant species, especially desert shrubs, could significantly alter soil chemistry and subsequently ecosystem biogeochemistry and function.

  7. Biobehavioral mechanisms of topiramate's effects on alcohol use: an investigation pairing laboratory and ecological momentary assessments.

    Science.gov (United States)

    Miranda, Robert; MacKillop, James; Treloar, Hayley; Blanchard, Alexander; Tidey, Jennifer W; Swift, Robert M; Chun, Thomas; Rohsenow, Damaris J; Monti, Peter M

    2016-01-01

    Topiramate reduces drinking, but little is known about the mechanisms that precipitate this effect. This double-blind randomized placebo-controlled study assessed the putative mechanisms by which topiramate reduces alcohol use among 96 adult non-treatment-seeking heavy drinkers in a laboratory-based alcohol cue reactivity assessment and in the natural environment using ecological momentary assessment methods. Topiramate reduced the quantity of alcohol heavy drinkers consumed on drinking days and reduced craving while participants were drinking but did not affect craving outside of drinking episodes in either the laboratory or in the natural environment. Topiramate did not alter the stimulant or sedative effects of alcohol ingestion during the ascending limb of the blood alcohol curve. A direct test of putative mechanisms of action using multilevel structural equation mediation models showed that topiramate reduced drinking indirectly by blunting alcohol-induced craving. These findings provide the first real-time prospective evidence that topiramate reduces drinking by reducing alcohol's priming effects on craving and highlight the importance of craving as an important treatment target of pharmacotherapy for alcoholism. © 2014 Society for the Study of Addiction.

  8. Animal behaviour shapes the ecological effects of ocean acidification and warming: moving from individual to community-level responses.

    Science.gov (United States)

    Nagelkerken, Ivan; Munday, Philip L

    2016-03-01

    Biological communities are shaped by complex interactions between organisms and their environment as well as interactions with other species. Humans are rapidly changing the marine environment through increasing greenhouse gas emissions, resulting in ocean warming and acidification. The first response by animals to environmental change is predominantly through modification of their behaviour, which in turn affects species interactions and ecological processes. Yet, many climate change studies ignore animal behaviour. Furthermore, our current knowledge of how global change alters animal behaviour is mostly restricted to single species, life phases and stressors, leading to an incomplete view of how coinciding climate stressors can affect the ecological interactions that structure biological communities. Here, we first review studies on the effects of warming and acidification on the behaviour of marine animals. We demonstrate how pervasive the effects of global change are on a wide range of critical behaviours that determine the persistence of species and their success in ecological communities. We then evaluate several approaches to studying the ecological effects of warming and acidification, and identify knowledge gaps that need to be filled, to better understand how global change will affect marine populations and communities through altered animal behaviours. Our review provides a synthesis of the far-reaching consequences that behavioural changes could have for marine ecosystems in a rapidly changing environment. Without considering the pervasive effects of climate change on animal behaviour we will limit our ability to forecast the impacts of ocean change and provide insights that can aid management strategies. © 2015 John Wiley & Sons Ltd.

  9. Cytogenetic effects of weak and combined actions in plants in connection with a problem of ecological rating

    International Nuclear Information System (INIS)

    Geras'kin, S.A.; Dikarev, V.G.; Udalova, A.A.; Dikareva, N.S.; Vasil'ev, D.V.; Evseeva, T.I.

    2002-01-01

    It is compared sanitary-hygienic and ecological approaches to rating of ionizing radiation action. The features of formation of cytogenetic effects in plants in conditions of separate and combined with factors of other nature action of ionizing radiation low doses are considered. (author)

  10. Climate and Land Use Change Effects on Ecological Resources in Three Watersheds: A Synthesis Report (Final Report)

    Science.gov (United States)

    EPA announced the availability of the final report, Climate and Land-Use Change Effects on Ecological Resources in Three Watersheds: A Synthesis Report. This report provides a summary of climate change impacts to selected watersheds and recommendations for how to improv...

  11. Towards More Effective Water Quality Governance : A Review of Social-Economic, Legal and Ecological Perspectives and Their Interactions

    NARCIS (Netherlands)

    van Rijswick, H.F.M.W.|info:eu-repo/dai/nl/099909189; Wuijts, S.; Driessen, P.P.J.|info:eu-repo/dai/nl/069081417

    2018-01-01

    In this article, social-economic, legal and ecological perspectives on effectiveness of water quality governance and their interactions have been studied. Worldwide, authorities are facing the challenge of restoring and preserving aquatic ecosystems in accordance with the United Nations Sustainable

  12. Ecological Models to Predict and Test the Effects of Chemical Stressors: Integration across 2 EPA STAR cooperative agreements

    Science.gov (United States)

    Accessible tools to quantify adverse outcomes pathways (AOPs) that can predict the ecological effects of chemicals and other stressors are a major goal of Chemical Safety and Sustainability research within US EPA’s Office of Research and Development. To address this goal, w...

  13. The ecological effects of water level fluctuation and phosphate enrichment in mesotrophic peatlands are strongly mediated by soil chemistry

    NARCIS (Netherlands)

    Mettrop, I.S.; Rutte, M.D.; Kooijman, A.M.; Lamers, L.P.M.

    2015-01-01

    Since the re-establishment of a more natural water regime is considered by water management in wetlands with artificially stable water levels, the biogeochemical and ecological effects of water level fluctuation with different nutrient loads should be investigated. This is particularly important for

  14. Protocols for Mapping and Characterizing Land Use/Land Cover in Riparian Zones

    National Research Council Canada - National Science Library

    Johnson, Michaela R; Zelt, Ronald B

    2005-01-01

    .... Characterization of riparian systems is critical to a comprehensive understanding of nutrient enrichment effects on stream ecosystems because riparian functions provide an important ecological...

  15. Effectiveness of mobile technologies delivering Ecological Momentary Interventions for stress and anxiety: a systematic review.

    Science.gov (United States)

    Loo Gee, Brendan; Griffiths, Kathleen M; Gulliver, Amelia

    2016-01-01

    Mobile technologies may be suitable for delivering Ecological Momentary Interventions (EMI) to treat anxiety in real-time. This review aims to synthesize evidence on the effectiveness of EMI for treating anxiety conditions. Four databases and the reference lists of previous studies were searched. A total of 1949 abstracts were double screened for inclusion. Sufficient studies were available to undertake a quantitative meta-analysis on EMIs on generalized anxiety symptoms. The 15 randomized trials and randomized controlled trials examined anxiety (n = 7), stress (n = 3), anxiety and stress (n = 2), panic disorder (n = 2), and social phobia (n = 1). Eight EMIs comprised self-monitoring integrated with therapy modules, seven comprised multimedia content, and three comprised self-monitoring only. The quality of studies presented high risk of biases. Meta-analysis (n = 7) demonstrated that EMIs reduced generalized anxiety compared to control and/or comparison groups (Effect Size (ES) = 0.32, 95% CI, 0.12-0.53). Most EMIs targeting stress were reported effective relative to control as were the two EMIs targeting panic disorders. The EMI targeting social phobia was not effective. EMIs have potential in treating both anxiety and stress. However, few high-quality trials have been conducted for specific anxiety disorders. Further trials are needed to assess the value of EMI technologies for anxiety in enhancing existing treatments. This study found a small significant effect of EMI studies on reducing generalized anxiety. Studies on stress demonstrated EMI was effective compared to control, with the small number of studies on panic and social phobia demonstrating mixed results. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. No effect of unemployment on intimate partner-related femicide during the financial crisis: a longitudinal ecological study in Spain.

    Science.gov (United States)

    Torrubiano-Domínguez, J; Vives-Cases, C; San-Sebastián, M; Sanz-Barbero, B; Goicolea, I; Álvarez-Dardet, C

    2015-09-30

    Spain's financial crisis has been characterized by an increase in unemployment. This increase could have produced an increase in deaths of women due to intimate partner-related femicides (IPF). This study aims to determine whether the increase in unemployment among both sexes in different regions in Spain is related to an increase in the rates of IPF during the current financial crisis period. An ecological longitudinal study was carried out in Spain's 17 regions. Two study periods were defined: pre-crisis period (2005-2007) and crisis period (2008-2013). IPF rates adjusted by age and unemployment rates for men and women were calculated. We fitted multilevel linear regression models in which observations at level 1 were nested within regions according to a repeated measurements design. Rates of unemployment have progressively increased in Spain, rising above 20 % from 2008 to 2013 in some regions. IPF rates decreased in some regions during crisis period with respect to pre-crisis period. The multilevel analysis does not support the existence of a significant relationship between the increase in unemployment in men and women and the decrease in IPF since 2008. The increase in unemployment in men and women in Spain does not appear to have an effect on IPF. The results of the multilevel analysis discard the hypothesis that the increase in the rates of unemployment in women and men are related to an increase in IPF rates. The decline in IPF since 2008 might be interpreted as the result of exposure to other factors such as the lower frequency of divorces in recent years or the medium term effects of the integral protection measures of the law on gender violence that began in 2005.

  17. Environmental assessment for the satellite power system-concept development and evaluation program-microwave health and ecological effects

    Energy Technology Data Exchange (ETDEWEB)

    1980-11-01

    This report is concerned with the potential health and ecological effects of the microwave beam from the microwave power transmission system (MPTS) of the satellite power system (SPS). The report is written in the form of a detailed critical review of selected scientific articles from the published literature on the biological effects of nonionizing electromagnetic radiation, followed by an assessment of the possible effects of the SPS, based on exposure values for the reference system (US DOE and NASA, 1978).

  18. Nonlinear Dynamic in an Ecological System with Impulsive Effect and Optimal Foraging

    Directory of Open Access Journals (Sweden)

    Min Zhao

    2014-01-01

    Full Text Available The population dynamics of a three-species ecological system with impulsive effect are investigated. Using the theories of impulsive equations and small-amplitude perturbation scales, the conditions for the system to be permanent when the number of predators released is less than some critical value can be obtained. Furthermore, because the predator in the system follows the predictions of optimal foraging theory, it follows that optimal foraging promotes species coexistence. In particular, the less beneficial prey can support the predator alone when the more beneficial prey goes extinct. Moreover, the influences of the impulsive effect and optimal foraging on inherent oscillations are studied using simulation, which reveals rich dynamic behaviors such as period-halving bifurcations, a chaotic band, a periodic window, and chaotic crises. In addition, the largest Lyapunov exponent and the power spectra of the strange attractor, which can help analyze the chaotic dynamic behavior of the model, are investigated. This information will be useful for studying the dynamic complexity of ecosystems.

  19. Using observation-level random effects to model overdispersion in count data in ecology and evolution

    Directory of Open Access Journals (Sweden)

    Xavier A. Harrison

    2014-10-01

    Full Text Available Overdispersion is common in models of count data in ecology and evolutionary biology, and can occur due to missing covariates, non-independent (aggregated data, or an excess frequency of zeroes (zero-inflation. Accounting for overdispersion in such models is vital, as failing to do so can lead to biased parameter estimates, and false conclusions regarding hypotheses of interest. Observation-level random effects (OLRE, where each data point receives a unique level of a random effect that models the extra-Poisson variation present in the data, are commonly employed to cope with overdispersion in count data. However studies investigating the efficacy of observation-level random effects as a means to deal with overdispersion are scarce. Here I use simulations to show that in cases where overdispersion is caused by random extra-Poisson noise, or aggregation in the count data, observation-level random effects yield more accurate parameter estimates compared to when overdispersion is simply ignored. Conversely, OLRE fail to reduce bias in zero-inflated data, and in some cases increase bias at high levels of overdispersion. There was a positive relationship between the magnitude of overdispersion and the degree of bias in parameter estimates. Critically, the simulations reveal that failing to account for overdispersion in mixed models can erroneously inflate measures of explained variance (r2, which may lead to researchers overestimating the predictive power of variables of interest. This work suggests use of observation-level random effects provides a simple and robust means to account for overdispersion in count data, but also that their ability to minimise bias is not uniform across all types of overdispersion and must be applied judiciously.

  20. Plant genetic variation mediates an indirect ecological effect between belowground earthworms and aboveground aphids.

    Science.gov (United States)

    Singh, Akanksha; Braun, Julia; Decker, Emilia; Hans, Sarah; Wagner, Agnes; Weisser, Wolfgang W; Zytynska, Sharon E

    2014-10-21

    Interactions between aboveground and belowground terrestrial communities are often mediated by plants, with soil organisms interacting via the roots and aboveground organisms via the shoots and leaves. Many studies now show that plant genetics can drive changes in the structure of both above and belowground communities; however, the role of plant genetic variation in mediating aboveground-belowground interactions is still unclear. We used an earthworm-plant-aphid model system with two aphid species (Aphis fabae and Acyrthosiphon pisum) to test the effect of host-plant (Vicia faba) genetic variation on the indirect interaction between the belowground earthworms (Eisenia veneta) on the aboveground aphid populations. Our data shows that host-plant variety mediated an indirect ecological effect of earthworms on generalist black bean aphids (A. fabae), with earthworms increasing aphid growth rate in three plant varieties but decreasing it in another variety. We found no effect of earthworms on the second aphid species, the pea aphid (A. pisum), and no effect of competition between the aphid species. Plant biomass was increased when earthworms were present, and decreased when A. pisum was feeding on the plant (mediated by plant variety). Although A. fabae aphids were influenced by the plants and worms, they did not, in turn, alter plant biomass. Previous work has shown inconsistent effects of earthworms on aphids, but we suggest these differences could be explained by plant genetic variation and variation among aphid species. This study demonstrates that the outcome of belowground-aboveground interactions can be mediated by genetic variation in the host-plant, but depends on the identity of the species involved.

  1. A review of fire effects on vegetation and soils in the Great Basin region: response and ecological site characteristics

    Science.gov (United States)

    Miller, Richard F.; Chambers, Jeanne C.; Pyke, David A.; Pierson, Fred B.; Williams, C. Jason

    2013-01-01

    This review synthesizes the state of knowledge on fire effects on vegetation and soils in semi-arid ecosystems in the Great Basin Region, including the central and northern Great Basin and Range, Columbia River Basin, and the Snake River Plain. We summarize available literature related to: (1) the effects of environmental gradients, ecological site, and vegetation characteristics on resilience to disturbance and resistance to invasive species; (2) the effects of fire on individual plant species and communities, biological soil crusts, seed banks, soil nutrients, and hydrology; and (3) the role of fire severity, fire versus fire surrogate treatments, and post-fire grazing in determining ecosystem response. From this, we identify knowledge gaps and present a framework for predicting plant successional trajectories following wild and prescribed fires and fire surrogate treatments. Possibly the three most important ecological site characteristics that influence a site’s resilience (ability of the ecological site to recover from disturbance) and resistance to invasive species are soil temperature/moisture regimes and the composition and structure of vegetation on the ecological site just prior to the disturbance event.

  2. Ecological quality of production: accounting approach on sustainable development

    Directory of Open Access Journals (Sweden)

    N.P. Syroid

    2016-12-01

    Full Text Available The specific weight of resource and power consuming technologies that is typical for Ukrainian economy, the absence of effective legal, administrative and economic mechanisms of management of nature and the low level of ecological society consciousness have led to the significant deterioration of environment state in Ukraine, excessive pollution of waters, air, and soil, accumulation of a large number of waste products. Besides, the produce as a result of such enterprises’ production affects consumers’ health badly. This causes the need to develop theory and methodology of production ecological quality accounting. The problem of quality is the most important factor of increasing of life level, economic, social and ecological security in market economy. This, the current research aims to formulate the essence of concept “ecological quality of production” The research determines that ecological quality is characterized by the following main 6 aspects: social, technical, legal, economic, aesthetic and ecological. If one of these six aspects does not work, we cannot speak about ecological quality of a certain commodity. Many various factors influence upon the level of ecological quality of products and services. According to their contents and directions, they can be united into the following main 6 groups: technical, organizational, economic and social, ecological and aesthetic and legal. The article determines the directions of production ecological quality increasing.

  3. Characterization of the ecological role of genes mediating acid resistance in Lactobacillus reuteri during colonization of the gastrointestinal tract.

    Science.gov (United States)

    Krumbeck, Janina A; Marsteller, Nathan L; Frese, Steven A; Peterson, Daniel A; Ramer-Tait, Amanda E; Hutkins, Robert W; Walter, Jens

    2016-07-01

    Rodent-derived strains of Lactobacillus reuteri densely colonize the forestomach of mice and possess several genes whose predicted functions constitute adaptations towards an acidic environment. The objective of this study was to systematically determine which genes of L. reuteri 100-23 contribute to tolerance towards host gastric acid secretion. Genes predicted to be involved in acid resistance were inactivated, and their contribution to survival under acidic conditions was confirmed in model gastric juice. Fitness of five mutants that showed impaired in vitro acid resistance were then compared through competition experiments in ex-germ-free mice that were either treated with omeprazole, a proton-pump inhibitor that suppresses acid secretion in the stomach, or left untreated. This analysis revealed that the urease cluster was the predominant factor in mediating resistance to gastric acid production. Population levels of the mutant, which were substantially decreased in untreated mice, were almost completely restored through omeprazole, demonstrating that urease production in L. reuteri is mainly devoted to overcome gastric acid. The findings provide novel information on the mechanisms by which L. reuteri colonizes its gastric niche and demonstrate that in silico gene predictions and in vitro tests have limitations for predicting the ecological functions of colonization factors in bacterial symbionts. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  4. Benchmarks for Developing Ecological Soil Screening Levels (ECO-SSL): Effects of Selenium on Soil Invertebrates

    National Research Council Canada - National Science Library

    Checkai, Ronald T; Simini, Michael; Kuperman, Roman; Phillips, Carlton T; Johnson, Dennis W; Higashi, Richard M; Fan, Teresa W-M; Sappington, Keith

    2004-01-01

    ...) for ecological receptors. Unfortunately data in the published literature were insufficient in quantity and quality to establish an Eco-SSL for selenium, critical in various DoD advanced technologies, and frequently...

  5. About the Atlantic Ecology Division (AED) of EPA's National Health and Environmental Effects Research Laboratory

    Science.gov (United States)

    The Atlantic Ecology Division (AED), conducts innovative research and predictive modeling to assess and forecast the risks of anthropogenic stressors to near coastal waters and their watersheds, to develop tools to support resilient watersheds.

  6. Aerobic Granular Sludge: Effect of Salt and Insights into Microbial Ecology

    KAUST Repository

    Wang, Zhongwei

    2017-01-01

    Like other artificial microbial ecosystems (e.g. CAS plant and anaerobic digester), a firm understanding of the microbial ecology of AGS system is essential for process design and optimization. The second part

  7. Characterization and Ecology of Carboxymethylcellulase-Producing Anaerobic Bacterial Communities Associated with the Intestinal Tract of the Pinfish, Lagodon rhomboides

    OpenAIRE

    Stellwag, E. J.; Smith, T. D.; Luczkovich, J. J.

    1995-01-01

    Carboxymethylcellulase (CMCase)-producing obligate anaerobes were isolated from the intestinal tract contents but not the feeding habitat of seagrass-consuming pinfish. Taxonomic characterization of these CMCase-producing strains revealed four taxonomic clusters; three were clostridial and one was of unknown taxonomic affinity. Our results demonstrated that the CMCase-producing obligate anaerobe community from pinfish differed from functionally similar microbial communities in terrestrial her...

  8. Effects of ionizing radiation upon natural populations and ecosystems. Final report. [Ecological perspectives in land use planning

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, J.F.

    1976-01-01

    Accomplishments throughout a 10-year period summarized include: a study of the effects of radiation from a ..gamma.. source on the ecology of the El Verde rain forest in Puerto Rico, with emphasis on the role of secondary succession in the recovery of forest ecosystems following irradiation; the effects of light and temperature on gaseous exchange in trees using /sup 14/CO/sub 2/ as a tracer in Palcourea; the nature of the sensitivity of pine trees to ionizing radiation and the possible synergistic effects of elevated ozone levels on radiosensitivity; the combined effects of radioactive and thermal effluents on plant communities of a swamp hardwood forest; and the development of a new conceptual approach to the evaluation of environmental quality, with emphasis on ecological perspectives in land use planning. (CH)

  9. Assessment of the health and environmental effects of power generation in the Midwest. Volume II. Ecological effects

    Energy Technology Data Exchange (ETDEWEB)

    Dvorak, A J; Pentecost, E D

    1977-04-01

    This report presents an initial evaluation of the major health and environmental issues associated with increased coal use in the six Midwestern states of Illinois, Indiana, Michigan, Minnesota, Ohio, and Wisconsin. Using an integrated assessment approach, the evaluation proceeds from a base-line scenario of energy demand and facility siting for the period 1975 to 2020. Emphasis is placed on impacts from coal extraction, land reclamation, coal combustion for electrical generation, and coal gasification. The range of potential impacts and constraints is illustrated by a second scenario that represents an expected upper limit for coal utilization in Illinois. Volume I of the report includes a characterization of the energy demand and siting scenarios, coal related technologies, and coal resources, and the related impacts on air quality, water quality, and human health. Volume II includes background information on the native ecosystems, climate, soils, and agricultural land use and a description of the ecological impacts expected from coal utilization in southern Illinois, which as ecosystems representative of a large segment of the six-state area.

  10. Groundwater Inputs to Rivers: Hydrological, Biogeochemical and Ecological Effects Inferred by Environmental Isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Stellato, L. [Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE), Seconda Universita degli Studi di Napoli, Caserta (Italy); Newman, B. D. [Isotope Hydrology Section, International Atomic Energy Agency, Vienna (Austria)

    2013-05-15

    In an effort to improve river management, numerous studies over the past two decades have supported the concept that river water and groundwater need to be considered together, as part of a hydrologic continuum. In particular, studies of the interface between surface water and groundwater (the hyporheic zone) have seen the tight collaboration of catchment hydrologists and stream ecologists in order to elucidate processes affecting stream functioning. Groundwater and surface waters interact at different spatial and temporal scales depending on system hydrology and geomorphology, which in turn influence nutrient cycling and in-stream ecology in relation to climatic, geologic, biotic and anthropogenic factors. In this paper, groundwater inputs to rivers are explored from two different and complementary perspectives: the hydrogeological, describing the generally acknowledged mechanisms of streamflow generation and the main factors controlling stream-aquifer interactions, and the ecologic, describing the processes occurring at the hyporheical and the riparian zones and their possible effects on stream functioning and on nutrient cycling, also taking into consideration the impact of human activities. Groundwater inflows to rivers can be important controls on hot moment/hot spot type biogeochemical behaviors. A description of the common methods used to assess these processes is provided emphasizing tracer methods (including physical, chemical and isotopic). In particular, naturally occurring isotopes are useful tools to identify stream discharge components, biogeochemical processes involved in nutrient cycling (such as N and P dynamics), nutrient sources and transport to rivers, and subsurface storage zones and residence times of hyporheic water. Several studies which have employed isotope techniques to clarify the processes occurring when groundwater enters the river,are reported in this chapter, with a view to highlighting both the advantages and limitations of these

  11. Ecological effects of contaminants in McCoy Branch, 1991--1993

    Energy Technology Data Exchange (ETDEWEB)

    Ryon, M.G. [ed.

    1996-09-01

    The 1984 Hazardous and Solid Waste Amendments to the Resource Conservation and Recovery Act (RCRA) required assessment of all current and former solid waste management units. Following guidelines under RCRA and the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), a remedial investigation (RI) was required of the Y-12 Plant for their filled coal ash pond (FCAP) and associated areas on McCoy Branch. The RI process was initiated and assessments were presented. Because the disposal of coal ash in the ash pond, McCoy Branch, and Rogers Quarry was not consistent with the Tennessee Water Quality Act, several remediation steps were implemented between 1986 and 1994 for McCoy Branch to address disposal problems. The required ecological risk assessments of McCoy Branch watershed included provisions for biological monitoring of the watershed. The objectives of the biological monitoring were to (1) document changes in biological quality of McCoy Branch after completion of a pipeline bypassing upper McCoy Branch and further, after termination of all discharges to Rogers Quarry, (2) provide guidance on the need for additional remediation, and (3) evaluate the effectiveness of implemented remedial actions. The data from the biological monitoring program may also determine whether the goals of protection of human health and the environment of McCoy Branch are being accomplished.

  12. Complex foraging ecology of the red harvester ant and its effect on the soil seed bank

    Science.gov (United States)

    Luna, Pedro; García-Chávez, Juan Héctor; Dáttilo, Wesley

    2018-01-01

    Granivory is an important interaction in the arid and semi-arid zones of the world, since seeds form an abundant and nutritious resource in these areas. While species of the genus Pogonomyrmex have been studied in detail as seed predators, their impact on seed abundance in the soil has not yet been explored in sufficient depth. We studied the impact of the harvesting activities of the ant Pogonomyrmex barbatus on seed abundance in the soil of the Zapotitlán valley, Mexico. We found that P. barbatus activity significantly impacts the abundance of seeds in the soil, which is lower in the sites where P. barbatus forages than it is in sites with no recorded foraging. We also found that P. barbatus distributes intact seeds of three tree species, two of which are nurse plants, and could consequently be promoting the establishment of these species. Using tools derived from graph theory, we observed that the ant-seed interactions exhibit a nested pattern; where more depredated seed species seem to be the more spatially abundant in the environment. This study illustrates the complex foraging ecology of the harvester ant P. barbatus and elucidates its effect on the soil seed bank in a semi-arid environment.

  13. Proximal ecological effects of the 1980 eruptions of Mount St. Helens

    Science.gov (United States)

    Swanson, F. J.

    1988-01-01

    The diversity of ecosystems and volcanic processes involved in the 1980 eruptions of Mount St. Helens, southwest Washington, provide an excellent setting for examining effects of volcanic events on ecosystems. These eruptions included a lateral blast, debris avalanche, mudflows, pyroclastic flows, and airfall tephra. Affected ecosystems within 30 km of the vent were lakes, streams, upland and riparian forest, and meadows. Ecological disturbances imposed by the Mount St. Helens events were predominantly physical, rather than climatic or chemical which are the dominant classes of disturbances considered in analysis of global catastrophes. Analysis of ecosystem response to disturbance should be based on consideration of composition and structure of the predisturbance system in terms that represent potential survivability of organisms, mechanisms in the primary disturbance, initial survivors, secondary disturbances arising from the primary disturbance and the biological responses to secondary disturbances, invasion of the site by new propagules, interactions among secondary disturbance processes and surviving and invading organisms. Predicting ecosystem response to disturbance is enchanced by considering the mechanisms of disturbance rather than type of disturbance. In the 1980 Mount St. Helens events, the disturbance types, involved primarily the mechanisms of sedimentation, heating, and shear stress. Each disturbance type involved one or more mechanisms. Ecosystem response varied greatly across the landscape. Analysis of ecosystem response to disturbance, regardless of type, should include detailed consideration of the properties of individual species, primary and secondary disturbance mechanisms, and their distributions across landscapes.

  14. Significance and effect of ecological rehabilitation project in inland river basins in northwest China.

    Science.gov (United States)

    Wang, Yu; Feng, Qi; Chen, Lijuan; Yu, Tengfei

    2013-07-01

    The Ecological Water Transfer and Rehabilitation Project in the arid inland area of northwest China is an important measure in restoring a deteriorated ecosystem. However, the sustainability of the project is affected by many socio-economic factors. This article examines the attitudes of the local populace toward the project, its impact on the livelihood of the people, and the positive effects of water-efficient agricultural practices in Ejina County. Related data were collected through questionnaire surveys and group discussions. The results identified three critical issues that may influence the sustainability of the project in the study area. The first issue relates to the impact of the project on the livelihood of local herdsmen. The potential for the sustainability of the project is compromised because the livelihood of the herdsmen greatly depends on the compensation awarded by the project. The second issue is that the project did not raise the water resource utilization ratio, which may undermine its final purpose. Finally, the compensation provided by the project considers losses in agriculture, but neglects the externalities and public benefit of eco-water. Thus, appropriate compensation mechanisms should be established and adopted according to local economic, environmental, and social conditions. Some recommendations for improving the sustainability of the project are provided based on the results of this study.

  15. Some pedo-ecological problems concerning the effects of industrial emissions on forest sites

    Energy Technology Data Exchange (ETDEWEB)

    Gorny, M.

    1976-01-01

    This study presents part of a long-term research report on the impact of emissions from a nitrogen plant upon soil zoocenoses and appraises the ecological functions of ants and earthworms. Ants (Formica polyctena) were almost the only organisms in the study area which revealed higher activity and ever increasing number of nests on the area of the strongest impact of industrial emissions. The mean increase over a 3 year period amounted to 3 nests per 10 ha per year. It was found that not only more microorganisms occurred in ant nests than in the soil adjoining them, but also that the number of active forms including those nitrogen-fixing ones, was in general, remarkably higher. This suggests the possibility that microorganisms clean the nest air of the excess of nitrogen compounds. Earthworm secretions and soil surrounding them had more abundant microflora, when compared with the soil not influenced by earthworms. The species composition of earthworm microflora in the study area within the range of industrial emissions, was entirely different from that found in earthworms from the control area. Earthworms were introduced on polluted areas along with the organic matter under an amelioration treatment. Their activity although considerable, has to be evaluated as a short-term effect, since a sexually immature population is destined for extinction. It indicates that in the course of ameliorative treatments one has to consider not only vegetation requirements, but also those of soil organisms which condition the development and life of plants.

  16. Ecological and nonhuman biological effects of solar UV-B radiation

    International Nuclear Information System (INIS)

    Worrest, R.C.

    1984-01-01

    Recent studies regarding the impact of UV-B radiation upon ecological and nonhuman biological systems is the subject of the report. For years scientists and laymen alike have causally noted the impact of solar ultraviolet radiation upon the nonhuman component of the biosphere. Stratospheric ozone functions effectively as an ultraviolet screen by filtering out solar radiation in the 220-320 nm waveband as it penetrates through the atmosphere, thus allowing only small amounts of the longer wavelengths of radiation in the waveband to leak through to the surface of the earth. Although this radiation (UV-B radiation, 290-320 nm) comprises only a small fraction (lesser tha 1%) of the total solar spectrum, it can have a major impact on biological systems due to its actinic nature. Many organic molecules, most notably DNA, absorb UV-B radiation which can initiate photochemical reactions. It is life's ability, or lack thereof, to cope with enhanced levels of solar UV-B radiation that has generated concern over the potential depletion of stratospheric ozone

  17. Development of a zoning-based environmental-ecological-coupled model for lakes to assess lake restoration effect

    Science.gov (United States)

    Xu, Mengjia; Zou, Changxin; Zhao, Yanwei

    2017-04-01

    coupled models have been applied to simulate the spatial variation trends of ecological condition under ecological water supplement as an example to reflect the application effect in lake restoration and management. The simulation results indicate that the models can provide a useful tool for lake restoration and management. The simulated spatial variation trends can provide a foundation for establishing permissible ranges for a selected set of water quality indices for a series of management measures such as watershed pollution load control and ecological water transfer. Meanwhile, the coupled models can help us to understand processes taking place and the relations of interaction between components in the lake ecosystem and external conditions. Taken together, the proposed models we established show some promising applications as middle-scale or large-scale lake management tools for pollution load control and ecological water transfer. These tools quantify the implications of proposed future water management decisions.

  18. Cost assessment and ecological effectiveness of nutrient reduction options for mitigating Phaeocystis colony blooms in the Southern North Sea: an integrated modeling approach.

    Science.gov (United States)

    Lancelot, Christiane; Thieu, Vincent; Polard, Audrey; Garnier, Josette; Billen, Gilles; Hecq, Walter; Gypens, Nathalie

    2011-05-01

    Nutrient reduction measures have been already taken by wealthier countries to decrease nutrient loads to coastal waters, in most cases however, prior to having properly assessed their ecological effectiveness and their economic costs. In this paper we describe an original integrated impact assessment methodology to estimate the direct cost and the ecological performance of realistic nutrient reduction options to be applied in the Southern North Sea watershed to decrease eutrophication, visible as Phaeocystis blooms and foam deposits on the beaches. The mathematical tool couples the idealized biogeochemical GIS-based model of the river system (SENEQUE-RIVERSTRAHLER) implemented in the Eastern Channel/Southern North Sea watershed to the biogeochemical MIRO model describing Phaeocystis blooms in the marine domain. Model simulations explore how nutrient reduction options regarding diffuse and/or point sources in the watershed would affect the Phaeocystis colony spreading in the coastal area. The reference and prospective simulations are performed for the year 2000 characterized by mean meteorological conditions, and nutrient reduction scenarios include and compare upgrading of wastewater treatment plants and changes in agricultural practices including an idealized shift towards organic farming. A direct cost assessment is performed for each realistic nutrient reduction scenario. Further the reduction obtained for Phaeocystis blooms is assessed by comparison with ecological indicators (bloom magnitude and duration) and the cost for reducing foam events on the beaches is estimated. Uncertainty brought by the added effect of meteorological conditions (rainfall) on coastal eutrophication is discussed. It is concluded that the reduction obtained by implementing realistic environmental measures on the short-term is costly and insufficient to restore well-balanced nutrient conditions in the coastal area while the replacement of conventional agriculture by organic farming

  19. Environment ecological effect of 14C-chlorsulfuron and its safety evaluation

    International Nuclear Information System (INIS)

    Chen Zuyi; Cheng Wei

    1995-12-01

    The adsorption, migration, degradation, residues of 14 C-chlorsulfuron and ecological effects of its degradation products were reviewed by isotope trace technique. The results show that: (1) The adsorption of 14 C-chlorsulfuron in soil are rather weak and its migration are rather strong. (2) The degradation of chlorsulfuron in soils are slow. The bound residues of chlorsulfuron in dry land soil are very considerable and increasing with the incubation time, extractive residues decrease gradually. By means of TLC and radioactive assay the radioactive degradation products of 14 C-chlorsulfuron in soil belong to trinitrogen-aniline. (3) One wheat and rice-wheat seasons after its application, the soil and after-crop (rice) all have considerable residues. The residue of chlorsulfuron and its transfer coefficient are far more than that in its shoots, the latter are more than that in soil. It is not distributed evenly in the plants. The residue in roots is far more than that in plant, which explains clearly that the bad effect of chlorsulfuron on the growth of root is related with its high accumulation on root. (4) The residue products including bound residues of 14 C-chlorsulfuron in soils were available on after-crop (maize, bean, pea, rice and garden sass). The damage symptoms showed that the root system development were clearly suppressed and the seedling were effected on growth. The minimum suffer dose of bound residues is 10 μg/kg in the stage of seedling growth. (19 refs., 8 figs., 8 tabs.)

  20. Developing a concept of social-ecological-technological systems to characterize resilience of urban areas and infrastructure to extreme events

    Science.gov (United States)

    Chester, M.; Grimm, N. B.; Redman, C.; Miller, T.; McPherson, T.; Munoz-Erickson, T.; Chandler, D. G.

    2015-12-01

    Climate change is widely considered one of the greatest challenges to global sustainability, with extreme events being the most immediate way that people experience this phenomenon. Urban areas are particularly vulnerable to these events given their location, concentration of people, and increasingly complex and interdependent infrastructure. We are developing a conceptual framework for urban social-ecological-technological systems (SETS) that will allow researchers and practitioners to assess how infrastructure can be resilient, provide ecosystem services, improve social well being, and exploit new technologies in ways that benefit urban populations. The framework integrates the three domains of social and equity issues, environmental quality and protection, and technical/engineering aspects, to form a concept of infrastructure that occurs at the intersection of the domains. Examples show how the more common socioecological systems and socially sensitive engineering approaches that fail to incorporate the third dimension may elevate vulnerability to climate-related disaster. The SETS conceptual framework bridges currently siloed social science, environmental science, and engineering approaches to significantly advance research into the structure, function, and emergent properties of SETS. Extreme events like heat waves in Phoenix; coastal and urban flooding in the wake of superstorm Sandy and following hurricanes in Miami, FL; drought in Mexico; and urban flooding in Baltimore, Portland, San Juan PR, Syracuse, and Valdivia, Chile provide examples of the impacts of and vulnerability to extreme events that demand a new approach. The infrastructure of the future must be resilient, leverage ecosystem services, improve social well being, and exploit new technologies in ways that benefit all segments of urban populations and are appropriate to the particular urban contexts. These contexts are defined not only by the biophysical environment but also by culture and

  1. Effects of a herbicide-insecticide mixture in freshwater microcosms: Risk assessment and ecological effect chain

    International Nuclear Information System (INIS)

    Brink, Paul J. van den; Crum, Steven J.H.; Gylstra, Ronald; Bransen, Fred; Cuppen, Jan G.M.; Brock, Theo C.M.

    2009-01-01

    Effects of chronic application of a mixture of the herbicide atrazine and the insecticide lindane were studied in indoor freshwater plankton-dominated microcosms. The macroinvertebrate community was seriously affected at all but the lowest treatment levels, the zooplankton community at the three highest treatment levels, with crustaceans, caddisflies and dipterans being the most sensitive groups. Increased abundance of the phytoplankton taxa Cyclotella sp. was found at the highest treatment level. Threshold levels for lindane, both at population and community level, corresponded well with those reported in the literature. Atrazine produced fewer effects than expected, probably due to decreased grazer stress on the algae as a result of the lindane application. The safety factors set by the Uniform Principles for individual compounds were also found to ensure protection against chronic exposure to a mixture of a herbicide and insecticide at community level, though not always at the population level. - Effects of chronic application of a herbicide-insecticide mixture were studied in indoor freshwater plankton-dominated microcosms. Effects could well be explained by the effects of the individual chemicals alone, no synergetic effects were reported

  2. Characterizing critical phenomena via the Purcell effect

    Science.gov (United States)

    Silva Neto, M. B.; Szilard, D.; Rosa, F. S. S.; Farina, C.; Pinheiro, F. A.

    2017-12-01

    We investigate the role of phase transitions into the spontaneous-emission rate of a single quantum emitter embedded in a critical medium. Using a Landau-Ginzburg approach, we find that in the broken symmetry phase, the emission rate is reduced, or even suppressed, due to the photon mass generated by the Higgs mechanism. Remarkably, its sensitivity to the critical exponents of the phase transition allows for an optical determination of universality classes. When applied to the cases of superconductivity and superfluidity, we show that the Purcell effect also provides valuable information on spectroscopic and thermodynamic quantities, such as the size of the superconducting gap and the discontinuity in the specific heat at the transition. By unveiling that a deeper connection between the Purcell effect and phase transitions exists, we demonstrate that the former is an efficient optical probe of distinct critical phenomena and their associated observables.

  3. Health and ecological risk-based characterization of soil and sediment contamination in shipyard with long-term use of DDT-containing antifouling paint

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Guanlin; Zhang, Chao [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Wu, Guanglong; Ding, Qiong [Foreign Economic Cooperation Office, Ministry of Environmental Protection of China, Beijing, 100035 (China); Wang, Shijie [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Li, Fasheng, E-mail: Lifs@craes.org.cn [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China)

    2013-04-15

    Dichlorodiphenyltrichloroethane (DDT) was a frequently occurring type of persistent organic environmental pollutant in China and DDT-containing antifouling paint could be the main contributor of DDT to shipyards and fishing harbors. A field survey was conducted in a shipyard in southern China to investigate the content and distribution of DDT in soil and sediments. Human health and screening-level ecological risk assessments were conducted for DDT contamination in soil and sediments and the results indicated that total DDT in all samples tested exceeded present advisory safe limits. Analysis of the composition and distribution implicated DDT-containing antifouling paint used for ship maintenance as an important source of DDT. Individual and cumulative health risks for residents exceeded the extra lifetime cancer risks of 10{sup −6} and 10{sup −5}, mainly from exposure to soil, ingestion and dermal contact. DDT in sediments is associated with a high level of toxicity for the benthic community when > 99% of samples exceed the threshold concentration likely to be responsible for effects and severe effects. Further risk control for DDT is required to ensure safety for human health, the benthic community and the environment. - Highlights: ► DDT ranked high concentration both in sediments and soil in a shipyard. ► Composition analysis indicated DDT antifouling paint was the main source. ► High loading DDT in sediments resulted in high probability of ecological risks. ► Potential health risks for residents were mainly from the exposure of ingestion.

  4. Health and ecological risk-based characterization of soil and sediment contamination in shipyard with long-term use of DDT-containing antifouling paint

    International Nuclear Information System (INIS)

    Guo, Guanlin; Zhang, Chao; Wu, Guanglong; Ding, Qiong; Wang, Shijie; Li, Fasheng

    2013-01-01

    Dichlorodiphenyltrichloroethane (DDT) was a frequently occurring type of persistent organic environmental pollutant in China and DDT-containing antifouling paint could be the main contributor of DDT to shipyards and fishing harbors. A field survey was conducted in a shipyard in southern China to investigate the content and distribution of DDT in soil and sediments. Human health and screening-level ecological risk assessments were conducted for DDT contamination in soil and sediments and the results indicated that total DDT in all samples tested exceeded present advisory safe limits. Analysis of the composition and distribution implicated DDT-containing antifouling paint used for ship maintenance as an important source of DDT. Individual and cumulative health risks for residents exceeded the extra lifetime cancer risks of 10 −6 and 10 −5 , mainly from exposure to soil, ingestion and dermal contact. DDT in sediments is associated with a high level of toxicity for the benthic community when > 99% of samples exceed the threshold concentration likely to be responsible for effects and severe effects. Further risk control for DDT is required to ensure safety for human health, the benthic community and the environment. - Highlights: ► DDT ranked high concentration both in sediments and soil in a shipyard. ► Composition analysis indicated DDT antifouling paint was the main source. ► High loading DDT in sediments resulted in high probability of ecological risks. ► Potential health risks for residents were mainly from the exposure of ingestion

  5. Functional remediation components: A conceptual method of evaluating the effects of remediation on risks to ecological receptors.

    Science.gov (United States)

    Burger, Joanna; Gochfeld, Michael; Bunn, Amoret; Downs, Janelle; Jeitner, Christian; Pittfield, Taryn; Salisbury, Jennifer

    2016-01-01

    Governmental agencies, regulators, health professionals, tribal leaders, and the public are faced with understanding and evaluating the effects of cleanup activities on species, populations, and ecosystems. While engineers and managers understand the processes involved in different remediation types such as capping, pump and treat, and natural attenuation, there is often a disconnect between (1) how ecologists view the influence of different types of remediation, (2) how the public perceives them, and (3) how engineers understand them. The overall goal of the present investigation was to define the components of remediation types (= functional remediation). Objectives were to (1) define and describe functional components of remediation, regardless of the remediation type, (2) provide examples of each functional remediation component, and (3) explore potential effects of functional remediation components in the post-cleanup phase that may involve continued monitoring and assessment. Functional remediation components include types, numbers, and intensity of people, trucks, heavy equipment, pipes, and drill holes, among others. Several components may be involved in each remediation type, and each results in ecological effects, ranging from trampling of plants, to spreading invasive species, to disturbing rare species, and to creating fragmented habitats. In some cases remediation may exert a greater effect on ecological receptors than leaving the limited contamination in place. A goal of this conceptualization is to break down functional components of remediation such that managers, regulators, and the public might assess the effects of timing, extent, and duration of different remediation options on ecological systems.

  6. Effect of an intervention based on socio-ecological model in promoting physical activity of female employees

    Directory of Open Access Journals (Sweden)

    Amineh Sahranavard Gargari

    2018-03-01

    Full Text Available Although active life style is one of the main determining factors of health, the level of regular physical activities in women is less than in men and even this level decreases with aging. The aim of this study was to determine the effect of an intervention based on the social ecological model on promotion of physical activity among female employees. In this study, 160 women employed at Shabestar universities were selected, and randomly divided into two groups of control (n=80 and intervention (n=80. The intervention group received an instructional program according to the model, including one session for general instruction and four sessions for group discussion along with daily walking for 30 minutes within 8 weeks. In order to objectively measure the physical activity, the pedometer was used and to measure the perceived physical activity, the long form of International Physical Activity Questionnaire (IPAQ was applied. The variables related to the components of socio-ecological model were measured using the socio-ecological model questionnaire. A significant difference was found between two groups after the intervention in terms of That is, the average number of steps in walking in the intervention group increased significantly (from 4204 to 7882 steps per day, while it did not significantly increase in the control group. Thus, it can be argued that designing and implementing the interventional programs based on the socio-ecological model can promote physical activity behavior among employed women

  7. Effects of scarcity, aesthetics and ecology on wildlife auction prices of large African mammals.

    Science.gov (United States)

    Dalerum, Fredrik; Miranda, María; Muñiz, Cristina; Rodríguez, Plácido

    2018-02-01

    For successful integration of biological conservation into economic markets, economic processes need to capture ecological values. South African wildlife ranching is a tourist-based activity that generates unique information on the economic value of wildlife species. We used public data from South African wildlife auctions to evaluate if annual prices 1991-2012 related to species characteristics associated with scarcity, aesthetics and ecology of South African carnivores and ungulates. While none of the species characteristics influenced carnivore prices, ungulate prices were related to characteristics associated with novelty and aesthetics, which relative importance had increased over time. We raise both ecological and economic concerns for this apparent focus. Our results also suggest a potential importance of non-species-related factors, such as market and buyer characteristics. We encourage further evaluation of the relative influences of species characteristics versus factors that are intrinsically linked to economic processes on price variations in South African wildlife.

  8. Environmental characterization and radio-ecological impacts of non-nuclear industries on the Red Sea coast

    International Nuclear Information System (INIS)

    El Mamoney, M.H.; Khater, Ashraf E.M.

    2004-01-01

    The Red Sea is a deep semi-enclosed and narrow basin connected to the Indian Ocean by a narrow sill in the south and to the Suez Canal in the north. Oil industries in the Gulf of Suez, phosphate ore mining activities in Safaga-Quseir region and intensified navigation activities are non-nuclear pollution sources that could have serious radiological impacts on the marine environment and the coastal ecosystems of the Red Sea. It is essential to establish the radiological base-line data, which does not exist yet, and to investigate the present radio-ecological impact of the non-nuclear industries to preserve and protect the coastal environment of the Red Sea. Some natural and man-made radionuclides have been measured in shore sediment samples collected from the Egyptian coast of the Red Sea. The specific activities of 226 Ra and 210 Pb ( 238 U) series, 232 Th series, 40 K and 137 Cs (Bq/kg dry weight) were measured using gamma ray spectrometers based on hyper-pure germanium detectors. The specific activities of 210 Po ( 210 Pb) and uranium isotopes ( 238 U, 235 U and 234 U) (Bq/kg dry weight) were measured using alpha spectrometers based on surface barrier (PIPS) detectors after radiochemical separation. The absorbed radiation dose rates in air (nGy/h) due to natural radionuclides in shore sediment and radium equivalent activity index (Bq/kg) were calculated. The specific activity ratios of 228 Ra/ 226 Ra, 210 Pb/ 226 Ra, 226 Ra/ 238 U and 234 U/ 238 U were calculated for evaluation of the geo-chemical behaviour of these radionuclides. The average specific activity of 226 Ra ( 238 U) series, 232 Th series, 40 K and 210 Pb were 24.7, 31.4, 427.5 and 25.6 Bq/kg, respectively. The concentration of 137 Cs in the sediment samples was less than the lower limit of detection. The Red Sea coast is an arid region with very low rainfall and the sediment is mainly composed of sand. The specific activity of 238 U, 235 U and 234 U were 25.3, 2.9 and 25.0 Bq/kg. The average specific

  9. The effects of hydroelectric gates on rivers, hydro-ecological diagnostic and management aid. The Fontauliere example (Ardeche)

    International Nuclear Information System (INIS)

    Valentin, S.

    1996-01-01

    Hydropower generation induces artificial fluctuations of flow and thus of hydrodynamic parameters in rivers, downstream of hydroelectric impoundments. On the Fontauliere river (Ardeche basin, France), the ecological effects of two different hydro-peaking regimes were tested and compared to a reference upstream reach. Fish, invertebrate and epilithic communities were surveyed in these reaches. The results enables to classify the factors responsible for the observed effects. The base flow between peaks was the most important for the studied site. When it was too low, aquatic communities were de-structured in comparison with the natural reach. These results enabled to suggest a current velocity threshold to respect in order to determine acceptable base flow for this type of stream. They also enabled to guide for the impact evaluation of hydro-peaking sites. An ecological diagnosis should include the study of the structure and composition of the communities. (author). 22 refs., 2 figs., 4 tabs

  10. Effects of substrata and environmental conditions on ecological succession on historic shipwrecks

    Science.gov (United States)

    González-Duarte, Manuel M.; Fernández-Montblanc, Tomás; Bethencourt, Manuel; Izquierdo, Alfredo

    2018-01-01

    An understanding of the interactions between biological, chemical and physical dynamics is especially important for the adequate conservation of the Underwater Cultural Heritage. However, while physical and chemical processes are relatively well-investigated, the biological communities associated with these habitats are poorly studied. We compared the sessile community developed on panels of different materials placed on two historical shipwrecks, the Fougueux and the Bucentaure, from the Battle of Trafalgar (October 1805). Six materials used at the construction of vessels at the 18th and 19th centuries were selected: copper, brass, cast iron, carbon steel, pine and oak. The sessile community developed on the panels was studied two and 15 months after their immersion at the water to determine the effects of materials and environmental conditions (sediments, waves, hydrodynamic conditions, temperature and salinity) on ecological succession and the possible implications at the conservation of historical shipwrecks. On the Fougueux, the environmental conditions more strongly influenced the biological succession than the material type, with pioneer colonisers dominating the communities in both sampling periods. On the Bucentaure, exposed to more stable environmental conditions, the sessile community showed differences between sampling periods and among materials at the end of the experiment. Under these more stable environmental conditions, the material type showed a higher influence on the sessile community. Species that produce calcareous concretions developed on metallic panels, but were absent on wood panels, where the shipworm Teredo navalis was more abundant. The relationship between environmental conditions, sessile organisms and material type can influence the conservation status of the archaeological sites.

  11. Climate change effects on runoff, catchment phosphorus loading and lake ecological state, and potential adaptations.

    Science.gov (United States)

    Jeppesen, Erik; Kronvang, Brian; Meerhoff, Mariana; Søndergaard, Martin; Hansen, Kristina M; Andersen, Hans E; Lauridsen, Torben L; Liboriussen, Lone; Beklioglu, Meryem; Ozen, Arda; Olesen, Jørgen E

    2009-01-01

    Climate change may have profound effects on phosphorus (P) transport in streams and on lake eutrophication. Phosphorus loading from land to streams is expected to increase in northern temperate coastal regions due to higher winter rainfall and to a decline in warm temperate and arid climates. Model results suggest a 3.3 to 16.5% increase within the next 100 yr in the P loading of Danish streams depending on soil type and region. In lakes, higher eutrophication can be expected, reinforced by temperature-mediated higher P release from the sediment. Furthermore, a shift in fish community structure toward small and abundant plankti-benthivorous fish enhances predator control of zooplankton, resulting in higher phytoplankton biomass. Data from Danish lakes indicate increased chlorophyll a and phytoplankton biomass, higher dominance of dinophytes and cyanobacteria (most notably of nitrogen fixing forms), but lower abundance of diatoms and chrysophytes, reduced size of copepods and cladocerans, and a tendency to reduced zooplankton biomass and zooplankton:phytoplankton biomass ratio when lakes warm. Higher P concentrations are also seen in warm arid lakes despite reduced external loading due to increased evapotranspiration and reduced inflow. Therefore, the critical loading for good ecological state in lakes has to be lowered in a future warmer climate. This calls for adaptation measures, which in the northern temperate zone should include improved P cycling in agriculture, reduced loading from point sources, and (re)-establishment of wetlands and riparian buffer zones. In the arid Southern Europe, restrictions on human use of water are also needed, not least on irrigation.

  12. Assessment of creation prospects of the effective economic stimulation mechanism of ecologically sustainable oil and gas complex development

    Directory of Open Access Journals (Sweden)

    Sheveleva Anastasia, V.

    2015-12-01

    Full Text Available Negative anthropogenous impact on environment is now felt especially sharply and gains global character that can lead to economic and ecological collapse, eventually. One of the most large-scale subjects of the economic environment doing harm to environment are the enterprises of an oil and gas complex as they in large volumes throw out the polluting substances and in high volumes take natural resources. However the field of activity of such enterprises is priority for national economy, and difficult interchangeability of energy raw material resources demands from the state and the oil and gas enterprises of development within realization of complete branch ecological-economic policy of the economic mechanism of stimulation of ecologically sustainable development of an oil and gas complex. Experience of last years within regulation and stimulation of decrease in pollution shows that the most effective way of achievement of it is implementation of serious capital investments in introduction of the environmentally friendly technologies in production allowing to receive a smaller stream of pollution "at the exit" a production system, and also a recycling of resources that can be provided by introduction in practice of work of the company of the best available technologies. Problems of ecologically sustainable development will also be answered by problems of economy not only in production and power, but also in power - a consumer sector for what it is necessary to provide compliance of the technologies used in extracting and processing the energy sectors, with technologies of economy of energy in a consumer sector. In the paper in this regard much attention is paid to possibility of formation of such economic mechanism via the public-private partnership mechanism that means that ecological-economic strategy of development of the enterprises of an oil and gas complex have to be coordinated with power strategy of development of regions and the

  13. Ecological traps in shallow coastal waters-Potential effect of heat-waves in tropical and temperate organisms.

    Directory of Open Access Journals (Sweden)

    Catarina Vinagre

    Full Text Available Mortality of fish has been reported in tide pools during warm days. That means that tide pools are potential ecological traps for coastal organisms, which happen when environmental changes cause maladaptive habitat selection. Heat-waves are predicted to increase in intensity, duration and frequency, making it relevant to investigate the role of tide pools as traps for coastal organisms. However, heat waves can also lead to acclimatization. If organisms undergo acclimatization prior to being trapped in tide pools, their survival chances may increase. Common tide pool species (46 species in total were collected at a tropical and a temperate area and their upper thermal limits estimated. They were maintained for 10 days at their mean summer sea surface temperature +3°C, mimicking a heat-wave. Their upper thermal limits were estimated again, after this acclimation period, to calculate each species' acclimation response. The upper thermal limits of the organisms were compared to the temperatures attained by tide pool waters to investigate if 1 tide pools could be considered ecological traps and 2 if the increase in upper thermal limits elicited by the acclimation period could make the organisms less vulnerable to this threat. Tropical tide pools were found to be ecological traps for an important number of common coastal species, given that they can attain temperatures higher than the upper thermal limits of most of those species. Tide pools are not ecological traps in temperate zones. Tropical species have higher thermal limits than temperate species, but lower acclimation response, that does not allow them to survive the maximum habitat temperature of tropical tide pools. This way, tropical coastal organisms seem to be, not only more vulnerable to climate warming per se, but also to an increase in the ecological trap effect of tide pools.

  14. Effects of various ecological factors on radiostrontium uptake in two euryhaline teleosts: Mugil auratus Risso and Pleuronectes platessa L

    International Nuclear Information System (INIS)

    Amiard, J.-C.

    1975-11-01

    The effects of various ecological, biotic and abiotic factors (age, species, salinity, temperature, sediment, calcium overload, food) on the accumulation of 85 Sr were studied in two euryhaline Teleosts. Generally, all the physico-chemical and biotic factors tending to activate metabolism, slightly increased radiostrontium intake. Concentration factors were seldom above one for animals measured in toto. According to the concentration kinetics of 85 Sr, three types of organs were distinguished: bone-type tissues, soft tissues and digestive tract [fr

  15. Potential Environmental and Ecological Effects of Global Climate Change on Venomous Terrestrial Species in the Wilderness.

    Science.gov (United States)

    Needleman, Robert K; Neylan, Isabelle P; Erickson, Timothy

    2018-06-01

    Climate change has been scientifically documented, and its effects on wildlife have been prognosticated. We sought to predict the overall impact of climate change on venomous terrestrial species. We hypothesize that given the close relationship between terrestrial venomous species and climate, a changing global environment may result in increased species migration, geographical redistribution, and longer seasons for envenomation, which would have repercussions on human health. A retrospective analysis of environmental, ecological, and medical literature was performed with a focus on climate change, toxinology, and future modeling specific to venomous terrestrial creatures. Species included venomous reptiles, snakes, arthropods, spiders, and Hymenoptera (ants and bees). Animals that are vectors of hemorrhagic infectious disease (eg, mosquitos, ticks) were excluded. Our review of the literature indicates that changes to climatic norms will have a potentially dramatic effect on terrestrial venomous creatures. Empirical evidence demonstrates that geographic distributions of many species have already shifted due to changing climatic conditions. Given that most terrestrial venomous species are ectotherms closely tied to ambient temperature, and that climate change is shifting temperature zones away from the equator, further significant distribution and population changes should be anticipated. For those species able to migrate to match the changing temperatures, new geographical locations may open. For those species with limited distribution capabilities, the rate of climate change may accelerate faster than species can adapt, causing population declines. Specifically, poisonous snakes and spiders will likely maintain their population numbers but will shift their geographic distribution to traditionally temperate zones more often inhabited by humans. Fire ants and Africanized honey bees are expected to have an expanded range distribution due to predicted warming trends

  16. Landscape Ecology

    DEFF Research Database (Denmark)

    Christensen, Andreas Aagaard; Brandt, Jesper; Svenningsen, Stig Roar

    2017-01-01

    Landscape ecology is an interdisciplinary field of research and practice that deals with the mutual association between the spatial configuration and ecological functioning of landscapes, exploring and describing processes involved in the differentiation of spaces within landscapes......, and the ecological significance of the patterns which are generated by such processes. In landscape ecology, perspectives drawn from existing academic disciplines are integrated based on a common, spatially explicit mode of analysis developed from classical holistic geography, emphasizing spatial and landscape...... pattern analysis and ecological interaction of land units. The landscape is seen as a holon: an assemblage of interrelated phenomena, both cultural and biophysical, that together form a complex whole. Enduring challenges to landscape ecology include the need to develop a systematic approach able...

  17. Polymorphic toxin systems: Comprehensive characterization of trafficking modes, processing, mechanisms of action, immunity and ecology using comparative genomics

    Directory of Open Access Journals (Sweden)

    Zhang Dapeng

    2012-06-01

    Full Text Available Abstract Background Proteinaceous toxins are observed across all levels of inter-organismal and intra-genomic conflicts. These include recently discovered prokaryotic polymorphic toxin systems implicated in intra-specific conflicts. They are characterized by a remarkable diversity of C-terminal toxin domains generated by recombination with standalone toxin-coding cassettes. Prior analysis revealed a striking diversity of nuclease and deaminase domains among the toxin modules. We systematically investigated polymorphic toxin systems using comparative genomics, sequence and structure analysis. Results Polymorphic toxin systems are distributed across all major bacterial lineages and are delivered by at least eight distinct secretory systems. In addition to type-II, these include type-V, VI, VII (ESX, and the poorly characterized “Photorhabdus virulence cassettes (PVC”, PrsW-dependent and MuF phage-capsid-like systems. We present evidence that trafficking of these toxins is often accompanied by autoproteolytic processing catalyzed by HINT, ZU5, PrsW, caspase-like, papain-like, and a novel metallopeptidase associated with the PVC system. We identified over 150 distinct toxin domains in these systems. These span an extraordinary catalytic spectrum to include 23 distinct clades of peptidases, numerous previously unrecognized versions of nucleases and deaminases, ADP-ribosyltransferases, ADP ribosyl cyclases, RelA/SpoT-like nucleotidyltransferases, glycosyltranferases and other enzymes predicted to modify lipids and carbohydrates, and a pore-forming toxin domain. Several of these toxin domains are shared with host-directed effectors of pathogenic bacteria. Over 90 families of immunity proteins might neutralize anywhere between a single to at least 27 distinct types of toxin domains. In some organisms multiple tandem immunity genes or immunity protein domains are organized into polyimmunity loci or polyimmunity proteins. Gene-neighborhood-analysis of

  18. Hazard identification for human and ecological effects of sodium chloride road salt.

    Science.gov (United States)

    2007-07-01

    The New Hampshire Department of Environmental Services (DES) requested an evaluation of : the human and ecological risks associated with the application of sodium chloride (NaCl) road : salt to roadways. NaCl is the major de-icing agent used in NH to...

  19. The effect of taxonomic resolution on the assessment of ecological water quality classes

    NARCIS (Netherlands)

    Schmidt-Kloiber, A.; Nijboer, R.C.

    2004-01-01

    Within the ecological assessment of running waters based on benthic macroinvertebrates different levels of taxonomic resolution (species, genus, family and higher) are in use. Although assessment systems are often developed with detailed data on species level, water managers and other end-users

  20. Effects of the antibiotic enrofloxacin on the ecology of tropical eutrophic freshwater microcosms

    NARCIS (Netherlands)

    Rico, A.; Rocha Dimitrov, M.; Wijngaarden, van R.P.A.; Satapornvanit, K.; Smidt, H.; Brink, van den P.J.

    2014-01-01

    The main objective of the present study was to assess the ecological impacts of the fluoroquinolone antibiotic enrofloxacin on the structure and functioning of tropical freshwater ecosystems. Enrofloxacin was applied at a concentration of 1, 10, 100 and 1000µg/L for 7 consecutive days in 600-L

  1. Nitrogen deposition effects on Mediterranean-type ecosystems: An ecological assessment

    Science.gov (United States)

    R. Ochoa-Hueso; E.B. Allen; C. Branquinho; C. Cruz; T. Dias; Mark Fenn; E. Manrique; M.E. Pérez-Corona; L.J. Sheppard; W.D. Stock

    2011-01-01

    We review the ecological consequences of N deposition on the five Mediterranean regions of the world. Seasonality of precipitation and fires regulate the N cycle in these water-limited ecosystems, where dry N deposition dominates. Nitrogen accumulation in soils and on plant surfaces results in peaks of availability with the first winter rains. Decoupling between N...

  2. Effects of ecological compensation meadows on arthropod diversity in adjacent intensively managed grassland

    NARCIS (Netherlands)

    Albrecht, M.; Duelli, P.; Obrist, M.K.; Müller, C.; Schüpbach, B.; Kleijn, D.; Schmid, B.

    2010-01-01

    An important goal of ecological compensation areas (ECAs) is to increase biodiversity in adjacent intensively managed farmland and the agricultural landscape at large. We tested whether this goal can be achieved in the case of the agri-environmental restoration scheme implemented for Swiss grassland

  3. Lindenmayer DB and Likens GE (eds): Effective ecological monitoring [book review

    Science.gov (United States)

    Charles T. Scott

    2011-01-01

    Long-term ecological monitoring is becoming increasingly important but more challenging to fund. Lindenmayer and Likens describe the common characteristics of successful monitoring programs and of those that fail. They draw upon their monitoring experiences together, independently, and from a variety of other long-term monitoring programs around the world. They then...

  4. Effect of origin and composition of diet on ecological impact of the organic egg production chain

    NARCIS (Netherlands)

    Dekker, S.E.M.; Boer, de I.J.M.; Krimpen, van M.M.; Aarnink, A.J.A.; Groot Koerkamp, P.W.G.

    2013-01-01

    The objective of this research was to assess the potential to reduce the integral ecological impact (i.e. impact along the egg production chain per kg egg) of Dutch organic egg production by replacing currently used imported diet ingredients with Dutch diet ingredients. We realized this objective by

  5. The effect of some ecological factors on the intestinal parasite loads ...

    Indian Academy of Sciences (India)

    Some ecological factors that might potentially influence intestinal parasite loads in the Asian elephant (Elephas maximus Linn.) were investigated in the Nilgiris, southern India. Fresh dung samples from identified animals were analysed, and the number of eggs/g of dung used as an index of parasite load. Comparisons ...

  6. Predicting ecological responses in a changing ocean: the effects of future climate uncertainty.

    Science.gov (United States)

    Freer, Jennifer J; Partridge, Julian C; Tarling, Geraint A; Collins, Martin A; Genner, Martin J

    2018-01-01

    Predicting how species will respond to climate change is a growing field in marine ecology, yet knowledge of how to incorporate the uncertainty from future climate data into these predictions remains a significant challenge. To help overcome it, this review separates climate uncertainty into its three components (scenario uncertainty, model uncertainty, and internal model variability) and identifies four criteria that constitute a thorough interpretation of an ecological response to climate change in relation to these parts (awareness, access, incorporation, communication). Through a literature review, the extent to which the marine ecology community has addressed these criteria in their predictions was assessed. Despite a high awareness of climate uncertainty, articles favoured the most severe emission scenario, and only a subset of climate models were used as input into ecological analyses. In the case of sea surface temperature, these models can have projections unrepresentative against a larger ensemble mean. Moreover, 91% of studies failed to incorporate the internal variability of a climate model into results. We explored the influence that the choice of emission scenario, climate model, and model realisation can have when predicting the future distribution of the pelagic fish, Electrona antarctica . Future distributions were highly influenced by the choice of climate model, and in some cases, internal variability was important in determining the direction and severity of the distribution change. Increased clarity and availability of processed climate data would facilitate more comprehensive explorations of climate uncertainty, and increase in the quality and standard of marine prediction studies.

  7. Effect of ecological restoration programs on dust concentrations in the North China Plain: a case study

    Science.gov (United States)

    Long, Xin; Tie, Xuexi; Li, Guohui; Cao, Junji; Feng, Tian; Zhao, Shuyu; Xing, Li; An, Zhisheng

    2018-05-01

    In recent decades, the Chinese government has made a great effort in initiating large-scale ecological restoration programs (ERPs) to reduce the dust concentrations in China, especially for dust storm episodes. Using the Moderate Resolution Imaging Spectroradiometer (MODIS) land cover product, the ERP-induced land cover changes are quantitatively evaluated in this study. Two obvious vegetation protective barriers arise throughout China from the southwest to the northeast, which are well known as the Green Great Wall (GGW). Both the grass GGW and forest GGW are located between the dust source region (DSR) and the densely populated North China Plain (NCP). To assess the effect of ERPs on dust concentrations, a regional transport/dust model (WRF-DUST, Weather Research and Forecast model with dust) is applied to investigate the evolution of dust plumes during a strong dust storm episode from 2 to 8 March 2016. The WRF-DUST model generally performs reasonably well in reproducing the temporal variations and spatial distributions of near-surface [PMC] (mass concentration of particulate matter with aerodynamic diameter between 2.5 and 10 µm) during the dust storm event. Sensitivity experiments have indicated that the ERP-induced GGWs help to reduce the dust concentration in the NCP, especially in BTH (Beijing, Tianjin, and Hebei). When the dust storm is transported from the upwind DSR to the downwind NCP, the [PMC] reduction ranges from -5 to -15 % in the NCP, with a maximum reduction of -12.4 % (-19.2 µg m-3) in BTH and -7.6 % (-10.1 µg m-3) in the NCP. We find the dust plumes move up to the upper atmosphere and are transported from the upwind DSR to the downwind NCP, accompanied by dust decrease. During the episode, the forest GGW is nonsignificant in dust concentration control because it is of benefit for dry deposition and not for emission. Conversely, the grass GGW is beneficial in controlling dust erosion and is the dominant reason for [PMC] decrease in the NCP

  8. Effect of ecological restoration programs on dust concentrations in the North China Plain: a case study

    Directory of Open Access Journals (Sweden)

    X. Long

    2018-05-01

    Full Text Available In recent decades, the Chinese government has made a great effort in initiating large-scale ecological restoration programs (ERPs to reduce the dust concentrations in China, especially for dust storm episodes. Using the Moderate Resolution Imaging Spectroradiometer (MODIS land cover product, the ERP-induced land cover changes are quantitatively evaluated in this study. Two obvious vegetation protective barriers arise throughout China from the southwest to the northeast, which are well known as the Green Great Wall (GGW. Both the grass GGW and forest GGW are located between the dust source region (DSR and the densely populated North China Plain (NCP. To assess the effect of ERPs on dust concentrations, a regional transport/dust model (WRF-DUST, Weather Research and Forecast model with dust is applied to investigate the evolution of dust plumes during a strong dust storm episode from 2 to 8 March 2016. The WRF-DUST model generally performs reasonably well in reproducing the temporal variations and spatial distributions of near-surface [PMC] (mass concentration of particulate matter with aerodynamic diameter between 2.5 and 10 µm during the dust storm event. Sensitivity experiments have indicated that the ERP-induced GGWs help to reduce the dust concentration in the NCP, especially in BTH (Beijing, Tianjin, and Hebei. When the dust storm is transported from the upwind DSR to the downwind NCP, the [PMC] reduction ranges from −5 to −15 % in the NCP, with a maximum reduction of −12.4 % (−19.2 µg m−3 in BTH and −7.6 % (−10.1 µg m−3 in the NCP. We find the dust plumes move up to the upper atmosphere and are transported from the upwind DSR to the downwind NCP, accompanied by dust decrease. During the episode, the forest GGW is nonsignificant in dust concentration control because it is of benefit for dry deposition and not for emission. Conversely, the grass GGW is beneficial in controlling dust erosion and is the

  9. [Comparition of ecological security stress effects of artificial landscapes on natural landscapes in different rapid urban sprawl areas].

    Science.gov (United States)

    Lin, Mei Xia; Lin, Tao; Qiu, Quan Yi; Sun, Cai Ge; Deng, Fu Liang; Zhang, Guo Qin

    2017-04-18

    The expansion of built-up area will cause stress effect on the regional natural ecological security pattern during urbanization process. Taking rapid expanding regions of four inland and coastal cities as study areas, including Tongzhou in Beijing, Zhengding in Hebei, Tanggu in Tianjin and Xiamen in Fujian, we constructed regional landscape stress indexes according to the principle of landscape ecology and comparatively analyzed the landscape pattern characteristics of rapid expanding regions and the differences of stress effect of artificial landscapes on four natural landscapes ecological security pattern in the process of rapid urbanization. Results showed that landscape erosion indexes of Tongzhou, Zhengding, Tanggu and Xiamen in 2015 were 1.039, 0.996, 1.239 and 0.945, respectively, which indicated that the natural landscapes were eroded significantly. Natural landscape types of those four regions presented different threatened levels. Among all natural landscape types, unused land and waters were worst threatened in Tongzhou, Zhengding and Tanggu, while in Xiamen cultivated land and waters showed the highest threat levels. The waters threat indexes of those four areas were all more than 0.743. Landscape isolation indexes of waters and unused land of the inland cities were greater than those of coastal cities, which meant water distribution of inland cities in the space was less gathered than that of coastal cities. Besides, compared with the other natural landscape, unused land and waters suffered the largest stress from artificial landscapes.

  10. Assessing the effects of customer innovativeness, environmental value and ecological lifestyles on residential solar power systems install intention

    International Nuclear Information System (INIS)

    Chen, Kee Kuo

    2014-01-01

    To understand the impact of environmental value, ecological lifestyle, customer innovativeness on customer intention to install solar power system (SPS) in their private houses, an empirical model was proposed. Customer innovativeness was treated as a second-order construct with two first-order dimensions, with each of the latter being measured by means of reflective indicators. Using structural equation modeling, data collected from 203 college students and faculties at a University of Taiwan were tested against the model. We found that environmental value has a positive impact on ecological lifestyle and SPS install intention. Although ecological lifestyle associates positively with SPS install intention, the effect disappears when environmental value is included in the model. The effect of customer innovativeness on SPS install intention results from the tendency of customer novelty seeking, while the impact of customer independent judgment-making on SPS install intention is insignificant. The model explained 76% of the total variations within SPS install intention. Managerial implications for promoting of SPS are considered, and suggestions for further research provided. - Highlights: • We integrate customer innovativeness into an environmental behavior model. • The impact of customer innovativeness on SPS install intention was confirmed. • The impact of novelty seeking on SPS install intention has been found. • Environmental value is the most important factor for SPS install intention. • The model explained 76% of the total variations within SPS install intention

  11. FORMATION OF ECOLOGICAL AWARENESS AND ENVIRONMENTAL CULTURE OF MEDICAL STUDENTS

    Directory of Open Access Journals (Sweden)

    Olena Snisar

    2017-03-01

    Full Text Available The article considers the important problem of searching and introducing innovative forms and methods of ecological upbringing and environmental education in the educational process of the medical educational establishment. Medical workers first face the negative impact of environmental problems on human health, therefore formation of high level of their environmental awareness and culture, ability to apply knowledge of medical ecology while performing their professional duties is an important condition for their qualitative vocational training. The aim of the article is to analyze the benefits of creating an environmental squad in the medical educational establishment with a purpose to create a high level of the studets’ environmental awareness, environmental culture and expositive behavior. The experience of the environmental squad Cherkasy medical academy to attract students to the ecological and elucidative and environmental protection, scientific research ecologically oriented. Effective methods and forms of environmental squad’s work in spreading ecological knowledge are characterized, the main topics of scientific research work are presented. Stages of forming ecological awareness and ecological culture of future doctors have been analyzed, while working in the environmental squad, from expanding and systematization of ecological knowledge to the development of ecological style of thinking and environmentally safe behavior. The results of the study led to the conclusion that activity of such structure as an ecological squad in the medical educational establishment provides improved ecological upbringing and environmental education and allows training of medical specialists, who understand the danger of a complicated ecological situation for human health, will promote healthy lifestyle, help reduce the negative impact of harmful factors on the health of patients, as well as a conscious citizen, which is a patriot of his country, take

  12. ECOLOGICAL EFFECTS OF METALS IN STREAMS ON A DEFENSE MATERIALS PROCESSING SITE IN SOUTH CAROLINA, USA

    Energy Technology Data Exchange (ETDEWEB)

    Paller, M.; Dyer, S.

    2009-09-01

    The Savannah River Site (SRS) is a 780 km{sup 2} U.S. Department of Energy facility near Aiken SC established in 1950 to produce nuclear materials. SRS streams are 'integrators' that potentially receive water transportable contaminants from all sources within their watersheds necessitating a GIS-based watershed approach to organize contaminant distribution data and accurately characterize the effects of multiple contaminant sources on aquatic organisms. Concentrations of metals in sediments, fish, and water were elevated in streams affected by SRS operations, but contaminant exposure models for Lontra Canadensis and Ceryle alcyon indicated that toxicological reference values were exceeded only by Hg and Al. Macroinvertebrate community structure was unrelated to sediment metal concentrations. This study indicated that (1) modeling studies and field bioassessments provide a complementary basis for addressing the individual and cumulative effects of contaminants, (2) habitat effects must be controlled when assessing contaminant impacts, (3) sensitivity analyses of contaminant exposure models are helpful in apportioning sampling effort, and (4) contaminants released during fifty years of industrial operations have not resulted in demonstrable harm to aquatic organisms in SRS streams.

  13. Ecological fate and effects of solvent-refined-coal (SRC) materials: a status report

    Energy Technology Data Exchange (ETDEWEB)

    Strand, J.A. III; Vaughan, B.E. (eds.)

    1981-10-01

    Non-occupational health effects associated with SRC operation will be determined by environmental factors governing the form, transport, and persistence of SRC materials and wastes - factors which also mediate exposure to man. Accordingly, the research described is an attempt to determine the fate of disposed solid wastes and spilled SRC materials, and it necessarily focuses on water soluble, persistent materials with greatest potential for mobility and incorporation into water and food supplies. Initially, aqueous equilibrations of SRC-II liquid material and SRC-I nongasified mineral residue were subjected to chemical characterization. Subsequently, laboratory studies were performed on the interaction of aqueous equilibrates of SRC-II liquid and SRC-I non-gasified mineral residue with soil materials isolated suspended sediments, and bottom sediments. These studies were designed to identify effects of specific sorption reactions ion or induced-ion exchange reactions, and toxicity of water soluble, biologically active materials derived from liquid and solid wastes. Results of these experiments have applicability to the environmental fate and effects of biologically active compounds released under different scenarios from product spills and solid waste disposal.

  14. Ecological Effects of Sea Level Rise: Advancing coastal management through integrated research and engagement

    Science.gov (United States)

    Kidwell, D. M.

    2012-12-01

    Rising sea level represents a significant threat to coastal communities and ecosystems through land loss, altered habitats, and increased vulnerability to coastal storms and inundation. This threat is exemplified in the northern Gulf of Mexico where low topography, expansive marshes, and a prevalence of tropical storms have already resulted in extensive coastal impacts. The development of robust predictive capabilities that incorporate complex biological processes with physical dynamics are critical for informed planning and restoration efforts for coastal ecosystems. Looking to build upon existing predictive modeling capabilities and allow for use of multiple model (i.e., ensemble) approaches, NOAA initiated the Ecological Effects of Sea Level Rise program in 2010 to advance physical/biological integrative modeling capabilities in the region with a goal to provide user friendly predictive tools for coastal ecosystem management. Focused on the northern Gulf of Mexico, this multi-disciplinary project led by the University of Central Florida will use in situ field studies to parameterize physical and biological models. These field studies will also result in a predictive capability for overland sediment delivery and transport that will further enhance marsh, oyster, and submerged aquatic vegetation models. Results from this integrated modeling effort are envisioned to inform management strategies for reducing risk, restoration and breakwater guidelines, and resource sustainability for project planning, among other uses. In addition to the science components, this project incorporates significant engagement of the management community through a management applications principle investigator and an advisory management committee. Routine engagement between the science team and the management committee, including annual workshops, are focused on ensuring the development of applicable, relevant, and useable products and tools at the conclusion of this project. Particular

  15. Ecological Ethics

    International Nuclear Information System (INIS)

    Oughton, Deborah

    2013-01-01

    Deborah Oughton started with a view of the work in progress by the ICRP TG 94 on ethics, from the historical context and the principles-based ethics in RP, to continue with an overview of the ethical theories and with the main area of elaboration which concerns the common values, to conclude with considerations about the implementation in different area such as biomedicine, nuclear safety and workers, ecological aspects, and environmental health and society. By reading again the ICRP and IAEA publications on the ethical aspects in the protection of environment from the effects of ionizing radiation, the presentation covers the various and different cultures within the history of environmental ethics, the perception of Nature and the theories of environmental ethics, in particular by focusing on anthropocentrism, biocentrism and ecocentrism, as philosophical worldwide views, and on conservation, biodiversity, sustainability, environmental justice and human dignity, as primary principles of environmental protection. The influence of western Christianity, with a view of man dominating over every creeping thing on earth, and of the non-western ideas, the human perception of Nature has been analyzed and discussed to conclude that, in reality then, the anthropocentrism, biocentrism and ecocentrism, as reflected in many cultures and religions, they all support the need to protect the environment and to recognise and preserve the diversity. Three challenges were then discussed in the presentation: the ecosystem approach and ecological economics, for example in the case of Fukushima by asking what is the economic cost of marine contamination; the ecosystem changes with attention to what harms, as in the case of the environment in the contaminated areas around Chernobyl; and the environmental consequences of remediation, which can be considered a source of controversy for environmental ethics and policy

  16. The effects of intercooling and regeneration on the thermo-ecological performance analysis of an irreversible-closed Brayton heat engine with variable-temperature thermal reservoirs

    International Nuclear Information System (INIS)

    Sogut, Oguz Salim; Ust, Yasin; Sahin, Bahri

    2006-01-01

    A thermo-ecological performance analysis of an irreversible intercooled and regenerated closed Brayton heat engine exchanging heat with variable-temperature thermal reservoirs is presented. The effects of intercooling and regeneration are given special emphasis and investigated in detail. A comparative performance analysis considering the objective functions of an ecological coefficient of performance, an ecological function proposed by Angulo-Brown and power output is also carried out. The results indicate that the optimal total isentropic temperature ratio and intercooling isentropic temperature ratio at the maximum ecological coefficient of performance conditions (ECOP max ) are always less than those of at the maximum ecological function ( E-dot max ) and the maximum power output conditions ( W-dot max ) leading to a design that requires less investment cost. It is also concluded that a design at ECOP max conditions has the advantage of higher thermal efficiency and a lesser entropy generation rate, but at the cost of a slight power loss

  17. Landscape Ecology

    DEFF Research Database (Denmark)

    Christensen, Andreas Aagaard; Brandt, Jesper; Svenningsen, Stig Roar

    2017-01-01

    , and the ecological significance of the patterns which are generated by such processes. In landscape ecology, perspectives drawn from existing academic disciplines are integrated based on a common, spatially explicit mode of analysis developed from classical holistic geography, emphasizing spatial and landscape...... to translate positivist readings of the environment and hermeneutical perspectives on socioecological interaction into a common framework or terminology....

  18. Effects of fragmentation on the spatial ecology of the California Kingsnake (Lampropeltis californiae)

    Science.gov (United States)

    Anguiano, Michael P.; Diffendorfer, James E.

    2015-01-01

    We investigated the spatial ecology of the California Kingsnake (Lampropeltis californiae) in unfragmented and fragmented habitat with varying patch sizes and degrees of exposure to urban edges. We radiotracked 34 Kingsnakes for up to 3 yr across four site types: interior areas of unfragmented ecological reserves, the urbanized edge of these reserves, large habitat fragments, and small habitat fragments. There was no relationship between California Kingsnake movements and the degree of exposure to urban edges and fragmentation. Home range size and movement patterns of Kingsnakes on edges and fragments resembled those in unfragmented sites. Average home-range size on each site type was smaller than the smallest fragment in which snakes were tracked. The persistence of California Kingsnakes in fragmented landscapes may be related directly to their small spatial movement patterns, home-range overlap, and ability to use urban edge habitat.

  19. Population-level impacts of pesticide-induced chronic effects on individuals depend more on ecology than toxicology

    DEFF Research Database (Denmark)

    Dalkvist, Trine; Topping, Christopher John; Forbes, Valery, E.

    2009-01-01

    at the population-level. Here we demonstrate how, using ABM modelling, assessments at the population-level can be obtained even for a pesticide with complex long-term effects such as epigenetic transmission of reproductive depression. By objectively fitting nonlinear models to the simulation outputs it was possible...... to compare population depression and recovery rates for a range of scenarios in which toxicity and exposure factors were varied. The system was differentially sensitive to the various factors, but vole ecology and behaviour were at least as important predictors of population-level effects as toxicology...

  20. Characterization of Iron and Steel Industry Slags to be Recycled under Ecological Aspects as a Recycling Concept for Waste Treatment

    International Nuclear Information System (INIS)

    Khalil, T.K.; Aly, H.F.; Bossert, J.

    1999-01-01

    The recycling and final disposal of different types of industrial waste play an important role in decreasing environmental pollution all over the world. Three different solid waste slags from steel industries situated in the Helwan area (Cairo-Egypt), namely blast furnace slags, oxygen converter slags arc furnace slags were studied. The morphology of the collected slag powders was examined using scanning electron microscopy (SEM). Surface characteristics of the slag powders were measured through nitrogen gas adsorption and application of the BET equation at 77 K. The thermal behaviour of the slag powders was studied with the help of differential thermal analysis (DTA) and thermogravimetry(TG)> Due to the presence of some changes in the DTA base lines, possibly as a result of phase transformations, X-ray diffraction was applied to identify these phases. The sintering behaviour of the compact slag powders after isostatic pressing was evaluated using dilatometry. The sintering and melting temperature of the studied samples were determined using heating microscopy. The effect of changing sintering temperature and of applying different isostatic pressures on the density and porosity of the slag powder compacts was investigated

  1. Delimiting the Boundary of Delhi for Effective Urban Political Ecology Investigations

    Directory of Open Access Journals (Sweden)

    Govind Singh

    2018-02-01

    Full Text Available Delhi, capital of the world’s largest democracy, is witnessing large-scale increase in population since the beginning of the twentieth century. Two prominent factors that have contributed to this include the shifting of capital of the British Raj from Calcutta (now Kolkata to Delhi in 1911 and the partition of India that accompanied its independence in 1947. Delhi continued to witness high rate of migration in post-independent India due to uneven implementation of development policies. Rising population led to spatial expansion and the largest connotation of Delhi today (National Capital Region is an area 36 times its size in 1947. Rising population has also had an adverse impact on Delhi’s natural resources. Consequently, clean air, water and land availability have become limited and Delhi today is undergoing a severe sustainability crisis. The latter requires urgent intervention for restoring Delhi’s urban ecosystem. Since urban areas are highly contested ecological spaces, urban ecological interventions are incomplete without political overtones. Thus, the success of urban ecological interventions lies in identifying politically correct boundaries which encompasses true ‘urban Delhi’ despite the political boundaries. This research contribution attempts to identify the geographical expanse of ‘urban Delhi’ amidst the various political terminologies that define Delhi. An understanding of various divisions and definitions of Delhi is also presented from the perspective of appreciating the challenges in urban planning. We conclude that urban ecology investigations in Delhi should be embedded within the ‘Delhi conurbation’, which represents a geographical area greater than the Delhi city-state but much smaller than Delhi NCR.

  2. Effects of ecological flooding on the temporal and spatial dynamics of carabid beetles (Coleoptera, Carabidae and springtails (Collembola in a polder habitat

    Directory of Open Access Journals (Sweden)

    Tanja Lessel

    2011-05-01

    Full Text Available Within the scope of the Integrated Rhine Program an ecological flood gate and channel was inserted into the polder “Ingelheim” to enhance animal and plant diversity. In 2008, carabid beetles and springtails were collected, using pitfall traps, to measure the effects of ecological flooding and a strong precipitation event at a flood-disturbed and a dry location in this area. At both localities, xerophilic and mesophilic carabid beetle species were dominant throughout the study period. The total number of individuals of hygrophilic species was comparatively constant, while species number increased, partly due to the changed moisture conditions caused by ecological flooding and strong precipitation. Carabid beetle diversity and evenness decreased marginally when ecological flooding was absent. Springtails represent a less mobile arthropod order, and as such the impact of ecological flooding was stronger. An increase in both numbers of species and individuals of hygrophilic and hygrotolerant species occurred in the flood-disturbed location after ecological flooding. After the sites at both locations had dried, the number of individuals belonging to these species declined rapidly. In contrast to carabid species, the strong precipitation event showed no influence on hygrophilic springtail species. Thus, collembolan diversity and evenness decreased markedly in the absence of flooding. We showed that ecological flooding has an influence on the spatial and temporal dynamics of different arthropod groups that inhabit the polder “Ingelheim”. These findings demonstrate the importance of using different arthropod groups as bioindicators in determining the ecological value of a particular polder design.

  3. Effects of Changes in Lugu Lake Water Quality on Schizothorax Yunnansis Ecological Habitat Based on HABITAT Model

    Science.gov (United States)

    Huang, Wei; Mynnet, Arthur

    Schizothorax Yunnansis is an unique fish species only existing in Lugu Lake, which is located in the southwestern China. The simulation and research on Schizothorax Yunnansis habitat environment have a vital significance to protect this rare fish. With the development of the tourism industry, there bring more pressure on the environmental protection. The living environment of Schizothorax Yunnansis is destroyed seriously because the water quality is suffering the sustaining pollution of domestic sewage from the peripheral villages. This paper analyzes the relationship between water quality change and Schizothorax Yunnansis ecological habitat and evalutes Schizothorax Yunnansis's ecological habitat impact based on HABITAT model. The results show that when the TP concentration in Lugu Lake does not exceed Schizothorax Yunnansis's survival threshold, Schizothorax Yunnansis can get more nutrients and the suitable habitat area for itself is increased. Conversely, it can lead to TP toxicity in the Schizothorax Yunnansis and even death. Therefore, unsuitable habitat area for Schizothorax Yunnansis is increased. It can be seen from the results that HABITAT model can assist in ecological impact assessment studies by translating results of hydrological, water quality models into effects on the natural environment and human society.

  4. Geomorphic and ecological effects of Hurricanes Katrina and Rita on coastal Louisiana marsh communities

    Science.gov (United States)

    Piazza, Sarai C.; Steyer, Gregory D.; Cretini, Kari F.; Sasser, Charles E.; Visser, Jenneke M.; Holm, Guerry O.; Sharp, Leigh A.; Evers, D. Elaine; Meriwether, John R.

    2011-01-01

    Hurricanes Katrina and Rita made landfall in 2005, subjecting the coastal marsh communities of Louisiana to various degrees of exposure. We collected data after the storms at 30 sites within fresh (12), brackish/intermediate (12), and saline (6) marshes to document the effects of saltwater storm surge and sedimentation on marsh community dynamics. The 30 sites were comprised of 15 pairs. Most pairs contained one site where data collection occurred historically (that is, prestorms) and one Coastwide Reference Monitoring System site. Data were collected from spring 2006 to fall 2007 on vegetative species composition, percentage of vegetation cover, aboveground and belowground biomass, and canopy reflectance, along with discrete porewater salinity, hourly surface-water salinity, and water level. Where available, historical data acquired before Hurricanes Katrina and Rita were used to compare conditions and changes in ecological trajectories before and after the hurricanes. Sites experiencing direct and indirect hurricane influences (referred to in this report as levels of influence) were also identified, and the effects of hurricane influence were tested on vegetation and porewater data. Within fresh marshes, porewater salinity was greater in directly impacted areas, and this heightened salinity was reflected in decreased aboveground and belowground biomass and increased cover of disturbance species in the directly impacted sites. At the brackish/intermediate marsh sites, vegetation variables and porewater salinity were similar in directly and indirectly impacted areas, but porewater salinity was higher than expected throughout the study. Interestingly, directly impacted saline marsh sites had lower porewater salinity than indirectly impacted sites, but aboveground biomass was greater at the directly impacted sites. Because of the variable and site-specific nature of hurricane influences, we present case studies to help define postdisturbance baseline conditions in

  5. Preparation, characterization and antibacterial effects of eco-friendly ...

    African Journals Online (AJOL)

    Purpose: To synthesize and characterize eco-friendly gold nanorods (Au-NRs) and to assess their effects against two bacterial strains. Methods: Synthesis of eco-friendly gold nanorods was done from an aqueous solution of chloroauric acid and cetyltrimethylammonium bromide by mixing Olea europaea fruit and Acacia ...

  6. [Ecological executive function characteristics and effects of executive function on social adaptive function in school-aged children with epilepsy].

    Science.gov (United States)

    Xu, X J; Wang, L L; Zhou, N

    2016-02-23

    To explore the characteristics of ecological executive function in school-aged children with idiopathic or probably symptomatic epilepsy and examine the effects of executive function on social adaptive function. A total of 51 school-aged children with idiopathic or probably symptomatic epilepsy aged 5-12 years at our hospital and 37 normal ones of the same gender, age and educational level were included. The differences in ecological executive function and social adaptive function were compared between the two groups with the Behavior Rating Inventory of Executive Function (BRIEF) and Child Adaptive Behavior Scale, the Pearson's correlation test and multiple stepwise linear regression were used to explore the impact of executive function on social adaptive function. The scores of school-aged children with idiopathic or probably symptomatic epilepsy in global executive composite (GEC), behavioral regulation index (BRI) and metacognition index (MI) of BRIEF ((62±12), (58±13) and (63±12), respectively) were significantly higher than those of the control group ((47±7), (44±6) and (48±8), respectively))(Pchildren with idiopathic or probably symptomatic epilepsy in adaptive behavior quotient (ADQ), independence, cognition, self-control ((86±22), (32±17), (49±14), (41±16), respectively) were significantly lower than those of the control group ((120±12), (59±14), (59±7) and (68±10), respectively))(Pchildren with idiopathic or probably symptomatic epilepsy. School-aged children with idiopathic or probably symptomatic epilepsy may have significantly ecological executive function impairment and social adaptive function reduction. The aspects of BRI, inhibition and working memory in ecological executive function are significantly related with social adaptive function in school-aged children with epilepsy.

  7. Microstructural characterization of radiation effects in nuclear materials

    CERN Document Server

    2017-01-01

    Microstructural Characterization of Radiation Effects in Nuclear Materials provides an overview into experimental techniques that can be used to examine those effects (both neutron and charged particle) and can be used by researchers, technicians or students as a tool to introduce them to the various techniques. The need to examine the effect of radiation on materials is becoming increasingly important as nuclear energy is emerging as a growing source of renewable energy. The book opens with a discussion of why it is important to study the effects of radiation on materials and looks at current and future reactor designs and the various constraints faced by materials as a result of those designs. The book also includes an overview of the radiation damage mechanisms. The next section explores the various methods for characterizing damage including transmission electron microscopy, scanning transmission electron microscopy, analytical electron microscopy, electron backscatter diffraction, atom probe tomography,...

  8. Disease ecology across soil boundaries: effects of below-ground fungi on above-ground host-parasite interactions.

    Science.gov (United States)

    Tao, Leiling; Gowler, Camden D; Ahmad, Aamina; Hunter, Mark D; de Roode, Jacobus C

    2015-10-22

    Host-parasite interactions are subject to strong trait-mediated indirect effects from other species. However, it remains unexplored whether such indirect effects may occur across soil boundaries and connect spatially isolated organisms. Here, we demonstrate that, by changing plant (milkweed Asclepias sp.) traits, arbuscular mycorrhizal fungi (AMF) significantly affect interactions between a herbivore (the monarch butterfly Danaus plexippus) and its protozoan parasite (Ophryocystis elektroscirrha), which represents an interaction across four biological kingdoms. In our experiment, AMF affected parasite virulence, host resistance and host tolerance to the parasite. These effects were dependent on both the density of AMF and the identity of milkweed species: AMF indirectly increased disease in monarchs reared on some species, while alleviating disease in monarchs reared on other species. The species-specificity was driven largely by the effects of AMF on both plant primary (phosphorus) and secondary (cardenolides; toxins in milkweeds) traits. Our study demonstrates that trait-mediated indirect effects in disease ecology are extensive, such that below-ground interactions between AMF and plant roots can alter host-parasite interactions above ground. In general, soil biota may play an underappreciated role in the ecology of many terrestrial host-parasite systems. © 2015 The Author(s).

  9. Disease ecology across soil boundaries: effects of below-ground fungi on above-ground host–parasite interactions

    Science.gov (United States)

    Tao, Leiling; Gowler, Camden D.; Ahmad, Aamina; Hunter, Mark D.; de Roode, Jacobus C.

    2015-01-01

    Host–parasite interactions are subject to strong trait-mediated indirect effects from other species. However, it remains unexplored whether such indirect effects may occur across soil boundaries and connect spatially isolated organisms. Here, we demonstrate that, by changing plant (milkweed Asclepias sp.) traits, arbuscular mycorrhizal fungi (AMF) significantly affect interactions between a herbivore (the monarch butterfly Danaus plexippus) and its protozoan parasite (Ophryocystis elektroscirrha), which represents an interaction across four biological kingdoms. In our experiment, AMF affected parasite virulence, host resistance and host tolerance to the parasite. These effects were dependent on both the density of AMF and the identity of milkweed species: AMF indirectly increased disease in monarchs reared on some species, while alleviating disease in monarchs reared on other species. The species-specificity was driven largely by the effects of AMF on both plant primary (phosphorus) and secondary (cardenolides; toxins in milkweeds) traits. Our study demonstrates that trait-mediated indirect effects in disease ecology are extensive, such that below-ground interactions between AMF and plant roots can alter host–parasite interactions above ground. In general, soil biota may play an underappreciated role in the ecology of many terrestrial host–parasite systems. PMID:26468247

  10. Adapting to climate change on Western public lands: addressing the ecological effects of domestic, wild, and feral ungulates.

    Science.gov (United States)

    Beschta, Robert L; Donahue, Debra L; DellaSala, Dominick A; Rhodes, Jonathan J; Karr, James R; O'Brien, Mary H; Fleischner, Thomas L; Deacon Williams, Cindy

    2013-02-01

    Climate change affects public land ecosystems and services throughout the American West and these effects are projected to intensify. Even if greenhouse gas emissions are reduced, adaptation strategies for public lands are needed to reduce anthropogenic stressors of terrestrial and aquatic ecosystems and to help native species and ecosystems survive in an altered environment. Historical and contemporary livestock production-the most widespread and long-running commercial use of public lands-can alter vegetation, soils, hydrology, and wildlife species composition and abundances in ways that exacerbate the effects of climate change on these resources. Excess abundance of native ungulates (e.g., deer or elk) and feral horses and burros add to these impacts. Although many of these consequences have been studied for decades, the ongoing and impending effects of ungulates in a changing climate require new management strategies for limiting their threats to the long-term supply of ecosystem services on public lands. Removing or reducing livestock across large areas of public land would alleviate a widely recognized and long-term stressor and make these lands less susceptible to the effects of climate change. Where livestock use continues, or where significant densities of wild or feral ungulates occur, management should carefully document the ecological, social, and economic consequences (both costs and benefits) to better ensure management that minimizes ungulate impacts to plant and animal communities, soils, and water resources. Reestablishing apex predators in large, contiguous areas of public land may help mitigate any adverse ecological effects of wild ungulates.

  11. Nanomaterials: biological effects and some aspects of applications in ecology and agriculture

    Science.gov (United States)

    Starodub, Nickolaj F.; Shavanova, Kateryna E.; Taran, Marina V.; Katsev, Andrey M.; Safronyuk, Sergey L.; Son'ko, Roman V.; Bisio, Chiara; Guidotti, Matteo

    2014-10-01

    Nanosized materials have shown a relevant potential for practical application in a broad number of research fields, in industrial production and in everyday life. However, these substances acquire new properties and therefore may be biologically very active. This raise questions their potential toxic effects on living organisms. In some cases the nanosized materials or nano-composites possess distinct positive properties in enhancing the adaptation of plants in unfavorable conditions and in decreasing the negative effect of some chemical substances. The information about the positive and negative effects of nano-materials as well as the data concerned to the innovative approaches used by authors for the rapid assessment of the total toxicity with the exploitation of bacteria, Daphnia and plants are given. In last case a special attention is paid to the control of natural bioluminescence and chemoluminescence of living medium of organisms, the energy of the seed germination and the efficiency of the photosynthetic apparatus in growing plants by the estimation of chlorophyll fluorescence by the special "Floratest" biosensor. Three specific clases of nano-materials are analysed: a) nano-particles ZnO, Ag2O, FeOx, TiO2 and others, b) colloidal suspension of the same compounds, and c) nanostructured layered clay materials (acid saponites and Nb-containing saponite clays). The next features are analyzed: the biocidal activity (for nanoparticles), the improvement of the nutrition of plants on calcareous soils (for colloidal structures), the activity and performances as heterogeneous catalysts (for Nb-containing saponites, as selective oxidation catalysts for toxic organosulfur compounds into non-noxious products). The chemical and physical characterization of the nanosized materials described here was studied by different spectrophotometric and microscopic techniques, including AFM and SEM.

  12. Expedited Site Characterization: A rapid, cost-effective process for preremedial site characterization

    International Nuclear Information System (INIS)

    Burton, J.C.; Walker, J.L.; Jennings, T.V.; Aggarwal, P.K.; Hastings, B.; Meyer, W.T.; Rose, C.M.; Rosignolo, C.L.

    1993-01-01

    Argonne National Laboratory has developed a unique, cost- and time-effective, technically innovative process for preremedial site characterization, referred to as Expedited Site Characterization (ESC). The cost of the ESC field sampling process ranges from 1/10 to 1/5 of the cost of traditional site characterization. The time required for this ESC field activity is approximately 1/30 of that for current methods. Argonne's preremedial site investigations based on this approach have been accepted by the appropriate regulatory agencies. The ESC process is flexible and neither site nor contaminant dependent. The process has been successfully tested and applied in site investigations of multiple contaminated landfills in New Mexico (for the US Department of the Interior's Bureau of Land Management [BLM]) and at former grain storage facilities in Nebraska and Kansas, contaminated with carbon tetrachloride (for the Department of Agriculture's Commodity Credit Corporation [CCC/USDA]). A working demonstration of this process was sponsored by the US Department of Energy (DOE) Office of Technology Development as a model of the methodology needed to accelerate site characterizations at DOE facilities. This report describes the application of the process in New Mexico, Nebraska and Kansas

  13. Education in ecology

    International Nuclear Information System (INIS)

    Marek, R.

    1993-01-01

    It is not enough to convey knowledge, insights and attitudes if education in ecology is to have fruitful effects. Space and opportunity for action and creativity must be provided in addition. This includes personal consumer habits (eating, transport, hygiene, leisure activities etc.); an individual workplace - in this case school - that can be shaped according to ecological needs. Beyond this, ecological maturation should not be confined to, but should transcend school, for instance in youth groups, citizens' committees, political parties. If school does not inspire action - including action outside school -then education in ecology could be smothered by the Midas effect, where all life is reduced to material, to the curriculum in this case. This book presents ecological projects that have been tried at schools. They aim at an education in ecology that is oriented to the pupil and open to experience. They could be an incentive for colleagues to conduct similar projects at their schools. The projects work from the pupils' own experience and aim at concrete action and activities in his or her own environment. They should encourage teachers to venture outside the classroom with the pupils and teach ecology where it takes place. (orig.) [de

  14. A survey of ecological risk assessment at DOE facilities

    International Nuclear Information System (INIS)

    Barnthouse, L.W.; Bascietto, J.; Joseph, T.; Bilyard, G.

    1992-01-01

    The US Department of Energy (DOE) Risk-Based Standards Working Group is studying standard-setting and remedial action based on realistic estimates of human health and ecological risks. Federal and state regulations require DOE to assess ecological risks due to present and past operation of DOE facilities and ecological damage caused by remedial actions. Unfortunately, little technical guidance has been provided by regulatory agencies about how these assessments should be performed or what constitutes an adequate assessment. Active ecological research, environmental characterization, and ecological risk assessment programs are already underway at many locations. Some of these programs were established more than 30 years ago. Because of the strength of its existing programs and the depth of expertise available within the DOE complex, the agency is in a position to lead in developing ecological risk assessment procedures that are fully consistent with the general principles defined by EPA and that will ensure environmentally sound and cost-effective restoration of its sites. As a prelude to guidance development, the working group conducted a survey of ecological risk assessment activities at a subset of major DOE facilities. The survey was intended to (1) identify approaches now being used in ecological risk assessments performed by DOE staff and contractors at each site, (2) record successes and failures of these approaches, (3) identify new technical developments with potential for general application to many DOE facilities, and (4) identify major data needs, data resources, and methodological deficiencies

  15. Evaluation of different radon guideline values based on characterization of ecological risk and visualization of lung cancer mortality trends in British Columbia, Canada.

    Science.gov (United States)

    Branion-Calles, Michael C; Nelson, Trisalyn A; Henderson, Sarah B

    2015-11-19

    There is no safe concentration of radon gas, but guideline values provide threshold concentrations that are used to map areas at higher risk. These values vary between different regions, countries, and organizations, which can lead to differential classification of risk. For example the World Health Organization suggests a 100 Bq m(-3)value, while Health Canada recommends 200 Bq m(-3). Our objective was to describe how different thresholds characterized ecological radon risk and their visual association with lung cancer mortality trends in British Columbia, Canada. Eight threshold values between 50 and 600 Bq m(-3) were identified, and classes of radon vulnerability were defined based on whether the observed 95(th) percentile radon concentration was above or below each value. A balanced random forest algorithm was used to model vulnerability, and the results were mapped. We compared high vulnerability areas, their estimated populations, and differences in lung cancer mortality trends stratified by smoking prevalence and sex. Classification accuracy improved as the threshold concentrations decreased and the area classified as high vulnerability increased. Majority of the population lived within areas of lower vulnerability regardless of the threshold value. Thresholds as low as 50 Bq m(-3) were associated with higher lung cancer mortality, even in areas with low smoking prevalence. Temporal trends in lung cancer mortality were increasing for women, while decreasing for men. Radon contributes to lung cancer in British Columbia. The results of the study contribute evidence supporting the use of a reference level lower than the current guideline of 200 Bq m(-3) for the province.

  16. The effects of ecology and evolutionary history on robust capuchin morphological diversity.

    Science.gov (United States)

    Wright, Kristin A; Wright, Barth W; Ford, Susan M; Fragaszy, Dorothy; Izar, Patricia; Norconk, Marilyn; Masterson, Thomas; Hobbs, David G; Alfaro, Michael E; Lynch Alfaro, Jessica W

    2015-01-01

    Recent molecular work has confirmed the long-standing morphological hypothesis that capuchins are comprised of two distinct clades, the gracile (untufted) capuchins (genus Cebus, Erxleben, 1777) and the robust (tufted) capuchins (genus Sapajus Kerr, 1792). In the past, the robust group was treated as a single, undifferentiated and cosmopolitan species, with data from all populations lumped together in morphological and ecological studies, obscuring morphological differences that might exist across this radiation. Genetic evidence suggests that the modern radiation of robust capuchins began diversifying ∼2.5 Ma, with significant subsequent geographic expansion into new habitat types. In this study we use a morphological sample of gracile and robust capuchin craniofacial and postcranial characters to examine how ecology and evolutionary history have contributed to morphological diversity within the robust capuchins. We predicted that if ecology is driving robust capuchin variation, three distinct robust morphotypes would be identified: (1) the Atlantic Forest species (Sapajus xanthosternos, S. robustus, and S. nigritus), (2) the Amazonian rainforest species (S. apella, S. cay and S. macrocephalus), and (3) the Cerrado-Caatinga species (S. libidinosus). Alternatively, if diversification time between species pairs predicts degree of morphological difference, we predicted that the recently diverged S. apella, S. macrocephalus, S. libidinosus, and S. cay would be morphologically comparable, with greater variation among the more ancient lineages of S. nigritus, S. xanthosternos, and S. robustus. Our analyses suggest that S. libidinosus has the most derived craniofacial and postcranial features, indicative of inhabiting a more terrestrial niche that includes a dependence on tool use for the extraction of imbedded foods. We also suggest that the cranial robusticity of S. macrocephalus and S. apella are indicative of recent competition with sympatric gracile capuchin

  17. Pursuing an ecological component for the Effect Factor in LCIA methods

    DEFF Research Database (Denmark)

    Cosme, Nuno Miguel Dias; Bjørn, Anders; Rosenbaum, Ralph K.

    have also been altered by past impacts. Model frameworks are usually built on stability, linearity of causality and expectation of a safe return to stable states if the stressor is minimised. However, the command-and-control paradigm has resulted in the erosion of natural resources and species...... EC50-based) or 1 (assuming that continuous stress affects reproduction rate), but these are all based on biological/physiological responses and do not add a true ecological component to the impact. Such factor simply changes the HC50 by 1 or 0.3 log units. A stressor with equal intensity in two...

  18. Community Ecology

    CERN Document Server

    1988-01-01

    This book presents the proceedings of a workshop on community ecology organized at Davis, in April, 1986, sponsored by the Sloan Foundation. There have been several recent symposia on community ecology (Strong et. al., 1984, Diamond and Case, 1987) which have covered a wide range of topics. The goal of the workshop at Davis was more narrow: to explore the role of scale in developing a theoretical approach to understanding communities. There are a number of aspects of scale that enter into attempts to understand ecological communities. One of the most basic is organizational scale. Should community ecology proceed by building up from population biology? This question and its ramifications are stressed throughout the book and explored in the first chapter by Simon Levin. Notions of scale have long been important in understanding physical systems. Thus, in understanding the interactions of organisms with their physical environment, questions of scale become paramount. These more physical questions illustrate the...

  19. An ecological approach to learning with technology: responding to tensions within the "wow-effect" phenomenon in teaching practices

    Science.gov (United States)

    Herro, Danielle

    2016-12-01

    This review explores Anne Kamstrupp's "The Wow-effect in Science Teacher Education" by examining her theorized "wow-effect" as a teaching enactment that may serve to engage students, but often fails to provide deep understanding of science content. My response extends her perspective of socio-materiality as means to understand the "wow-effect" by suggesting social constructivism provides a more accurate lens to disentangle the phenomenon. I react to her position that tension fields within the phenomenon include the relationship between new and old technologies, boredom and engagement, and active and sedentary learning. In this conversation, I point to a new way of conceptualizing using digital media in the classroom as ecology of learning that may serve to decrease problems associated with the "wow-effect".

  20. Ecological restoration and effect investigation of a river wetland in a semi-arid region, China

    Science.gov (United States)

    Xu, S.; Jiang, X.; Liu, Y.; Fu, Y.; Zhao, Q.

    2015-05-01

    River wetlands are heavily impacted by human intervention. The degradation and loss of river wetlands has made the restoration of river ecosystems a top priority. How to rehabilitate rivers and their services has been a research focus. The main goal of it is to restore the river wetland ecosystems with ecological methods. The Gudong River was selected as a study site in Chaoyang city in this study. Based on the analysis of interference factors in the river wetland degradation, a set of restoration techniques were proposed and designed for regional water level control, including submerged dikes, ecological embankments, revegetation and dredging. The restoration engineering has produced good results in water quality, eco-environment, and landscape. Monthly reports of the Daling River show that the water quality of Gudong River was better than Grade III in April 2013 compared with Grade V in May 2012. The economic benefit after restoration construction is 1.71 million RMB per year, about 1.89 times that before. The ratio of economic value, social value and eco-environmental value is 1:4:23.

  1. Dietary marker effects on fecal microbial ecology, fecal VFA, nutrient digestibility coefficients, and growth performance in finishing pigs.

    Science.gov (United States)

    Kerr, B J; Weber, T E; Ziemer, C J

    2015-05-01

    Use of indigestible markers such as Cr2O3, Fe2O3, and TiO2 are commonly used in animal studies to evaluate digesta rate of passage and nutrient digestibility. Yet, the potential impact of indigestible markers on fecal microbial ecology and subsequent VFA generation is not known. Two experiments utilizing a total of 72 individually fed finishing pigs were conducted to describe the impact of dietary markers on fecal microbial ecology, fecal ammonia and VFA concentrations, nutrient digestibility, and pig performance. All pigs were fed a common diet with no marker or with 0.5% Cr2O3, Fe2O3, or TiO2. In Exp. 1, after 33 d of feeding, fresh fecal samples were collected for evaluation of microbial ecology, fecal ammonia and VFA concentrations, and nutrient digestibility, along with measures of animal performance. No differences were noted in total microbes or bacterial counts in pig feces obtained from pigs fed the different dietary markers while Archaea counts were decreased (P = 0.07) in feces obtained from pigs fed the diet containing Fe2O 3compared to pigs fed the control diet. Feeding Cr2O3, Fe2O3, or TiO2 increased fecal bacterial richness (P = 0.03, 0.01, and 0.10; respectively) when compared to pigs fed diets containing no marker, but no dietary marker effects were noted on fecal microbial evenness or the Shannon-Wiener index. Analysis of denaturing gradient gel electrophoresis gels did not reveal band pattern alterations due to inclusion of dietary markers in pig diets. There was no effect of dietary marker on fecal DM, ammonia, or VFA concentrations. Pigs fed diets containing Cr2O3 had greater Ca, Cu, Fe, and P (P ≤ 0.02), but lower Ti ( P= 0.08) digestibility compared to pigs fed the control diet. Pigs fed diets containing Fe2O3 had greater Ca (P = 0.08) but lower Ti (P = 0.01) digestibility compared to pigs fed the control diet. Pigs fed diets containing TiO2 had greater Fe and Zn (P ≤ 0.09), but lower Ti ( P= 0.01) digestibility compared to pigs fed the

  2. The ecological framework for environmental effects monitoring: a perspective from outside the region

    International Nuclear Information System (INIS)

    Ray, J. P.

    2000-01-01

    An overview of key issues, early problems and experiences of the last two decades in environmental monitoring of offshore oil and natural gas exploration and production is provided, emphasizing that the key issues (What is being discharged? How much and how often? Where are things going in the environment? What are the short and long-term effects?) have not changed; we have a large body of scientific knowledge on the characterization of wastes, their fates in the marine environment and their zones of biological influence; we also have the experience gained over two decades of offshore exploration and production to provide guidance, and while every geographic region has its own uniqueness, the range of responses will not vary by orders of magnitude. It is suggested that it is not necessary to reinvent the wheel every time we move into a new exploration area. A more prudent strategy would be to concentrate on what is really unique about the particular area of interest, followed by a selective monitoring and assessment program to validate the data and the conclusions drawn from studies in other parts of the world. A number of specific studies done during the past two decades are identified as particularly significant in terms of variety of environments, target chemicals, target populations and environmental monitoring designs that may provide useful information for any pending environmental monitoring situation. Also included in this paper are valuable observations concerning the Canadian program of offshore environmental monitoring as gleaned from the papers presented and discussions which have taken place at this conference. 9 refs

  3. Antagonistic effect of Pseudomonas aeruginosa isolates from various ecological niches on Vibrio species pathogenic to crustaceans

    Institute of Scientific and Technical Information of China (English)

    Prabhakaran Priyaja; Puthumana Jayesh; Neil Scolastin Correya; Balachandran Sreelakshmi; Naduthalmuriparambil S Sudheer; Rosamma Philip; Isaac Sarogeni Bright Singh

    2014-01-01

    Objective: To abrogate pathogenic vibrios in aquaculture by testing the potential of Pseudomonas isolates from fresh water, brackish and marine environments as probiotics.Methods:Antagonistic activity of the compound against 7 Vibrio spp. was performed. Influence of salinity on the production of pyocyanin and the toxicity was done through the compound using brine shrimp lethality assay. Molecular characterization was performed to confirm that the isolates werePseudomonas aeruginosa. Results: Salinity was found to regulate the levels of pyocyanin production, with 5-10 g/L as the optimum. All Pseudomonas isolates grew at salinities ranging from 5 to 70 g/L. Isolates of marine origin produced detectable levels of pyocyanin up to 45 g/L salinity. Brackish and freshwater isolates ceased to produce pyocyanin at salinities above 30 g/L and 20 g/L, respectively. Culture supernatants of all 5 Pseudomonas isolates possessed the ability to restrict the growth of Vibrio spp. and maximum antagonistic effect on Vibrio harveyi was obtained when they were grown at salinities of 5 to 10 g/L. The marine isolate MCCB117, even when grown at a salinity of 45 g/L possessed the ability to inhibit Vibrio spp.Conclusions:Purification and structural elucidation of antagonistic compound were carried out. ideal for application in freshwater, MCCB102 and MCCB103 in brackish water and MCCB117 and The present investigation showed that Pseudomonas aeruginosa MCCB119 would be MCCB118 in marine aquaculture systems as putative probiotics in the management of vibrios.

  4. Antagonistic effect of Pseudomonas aeruginosa isolates from various ecological niches on Vibrio species pathogenic to crustaceans

    Directory of Open Access Journals (Sweden)

    Prabhakaran Priyaja

    2014-01-01

    Full Text Available Objective: To abrogate pathogenic vibrios in aquaculture by testing the potential of Pseudomonas isolates from fresh water, brackish and marine environments as probiotics. Methods: Purification and structural elucidation of antagonistic compound were carried out. Antagonistic activity of the compound against 7 Vibrio spp. was performed. Influence of salinity on the production of pyocyanin and the toxicity was done through the compound using brine shrimp lethality assay. Molecular characterization was performed to confirm that the isolates were Pseudomonas aeruginosa. Results: Salinity was found to regulate the levels of pyocyanin production, with 5-10 g/L as the optimum. All Pseudomonas isolates grew at salinities ranging from 5 to 70 g/L. Isolates of marine origin produced detectable levels of pyocyanin up to 45 g/L salinity. Brackish and freshwater isolates ceased to produce pyocyanin at salinities above 30 g/L and 20 g/L, respectively. Culture supernatants of all 5 Pseudomonas isolates possessed the ability to restrict the growth of Vibrio spp. and maximum antagonistic effect on Vibrio harveyi was obtained when they were grown at salinities of 5 to 10 g/L. The marine isolate MCCB117, even when grown at a salinity of 45 g/L possessed the ability to inhibit Vibrio spp. Conclusions: The present investigation showed that Pseudomonas aeruginosa MCCB119 would be ideal for application in freshwater, MCCB102 and MCCB103 in brackish water and MCCB117 and MCCB118 in marine aquaculture systems as putative probiotics in the management of vibrios.

  5. Cumulative effects of restoration efforts on ecological characteristics of an open water area within the Upper Mississippi River

    Science.gov (United States)

    Gray, B.R.; Shi, W.; Houser, J.N.; Rogala, J.T.; Guan, Z.; Cochran-Biederman, J. L.

    2011-01-01

    Ecological restoration efforts in large rivers generally aim to ameliorate ecological effects associated with large-scale modification of those rivers. This study examined whether the effects of restoration efforts-specifically those of island construction-within a largely open water restoration area of the Upper Mississippi River (UMR) might be seen at the spatial scale of that 3476ha area. The cumulative effects of island construction, when observed over multiple years, were postulated to have made the restoration area increasingly similar to a positive reference area (a proximate area comprising contiguous backwater areas) and increasingly different from two negative reference areas. The negative reference areas represented the Mississippi River main channel in an area proximate to the restoration area and an open water area in a related Mississippi River reach that has seen relatively little restoration effort. Inferences on the effects of restoration were made by comparing constrained and unconstrained models of summer chlorophyll a (CHL), summer inorganic suspended solids (ISS) and counts of benthic mayfly larvae. Constrained models forced trends in means or in both means and sampling variances to become, over time, increasingly similar to those in the positive reference area and increasingly dissimilar to those in the negative reference areas. Trends were estimated over 12- (mayflies) or 14-year sampling periods, and were evaluated using model information criteria. Based on these methods, restoration effects were observed for CHL and mayflies while evidence in favour of restoration effects on ISS was equivocal. These findings suggest that the cumulative effects of island building at relatively large spatial scales within large rivers may be estimated using data from large-scale surveillance monitoring programs. Published in 2010 by John Wiley & Sons, Ltd.

  6. Effectiveness of birds, butterflies, dragonflies, damselflies and invertebrates as indicators of freshwater ecological integrity

    Science.gov (United States)

    Chama, Lackson; Siachoono, Stanford

    2015-04-01

    Human activities such as mining and agriculture are among the major threats to biodiversity globally. Discharges from these activities have been shown to negatively affect ecological processes, leading to ecosystem degradation and species loss across biomes. Freshwater systems have been shown to be particularly vulnerable, as discharges tend to spread rapidly here than in other ecosystems. Hence, there is need to routinely monitor the quality of these systems if impacts of discharges from human activities are to be minimised. Besides the use of conventional laboratory techniques, several studies have recently shown that organisms such as birds, butterflies, dragonflies, damselflies and invertebrates are also good indicators of ecological integrity and should therefore be used as alternatives to monitoring the quality of various ecosystems. However, most of these studies have only studied one or two of these organisms against ecosystem health, and it remains unclear whether all of them respond similarly to changes in different drivers of environmental change. We investigated the response of the diversity of birds, butterflies, dragonflies, damselflies and invertebrates to changing water quality along the Kafue River in Zambia. Sampling was done at 13 different sampling points stretching over a distance of 60Km along the river. At each point, both the diversity of each organism and the water quality were assessed. Water quality was determined by testing its temperature, pH, redox, electrical conductivity, turbidity and copper parameters. We then tested how the diversity of each organism responded to changes in these water parameters. All water parameters varied significantly across sampling points. The diversity of birds and damselflies remained unaffected by any of the water parameters used. However, the diversity of butterflies reduced with increasing pH, turbidity and copper, albeit it remained unaffected by other water parameters. The diversity of dragonflies

  7. Acacia saligna’s soil legacy effects persist up to ten years after clearing: Implications for ecological restoration

    Czech Academy of Sciences Publication Activity Database

    Nsikani, M. M.; Novoa, Ana; van Wilgen, B. W.; Keet, J.-H.; Gaertner, M.

    2017-01-01

    Roč. 42, č. 8 (2017), s. 880-889 ISSN 1442-9985 R&D Projects: GA ČR GB14-36079G Institutional support: RVO:67985939 Keywords : ecological impact * enzyme activities * invader control * restoration Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 1.708, year: 2016

  8. Effects of economic crises on population health outcomes in Latin America, 1981-2010: an ecological study.

    Science.gov (United States)

    Williams, Callum; Gilbert, Barnabas James; Zeltner, Thomas; Watkins, Johnathan; Atun, Rifat; Maruthappu, Mahiben

    2016-01-06

    The relative health effects of changes in unemployment, inflation and gross domestic product (GDP) per capita on population health have not been assessed. We aimed to determine the effect of changes in these economic measures on mortality metrics across Latin America. Ecological study. Latin America (21 countries), 1981-2010. Uses multivariate regression analysis to assess the effects of changes in unemployment, inflation and GDP per capita on 5 mortality indicators across 21 countries in Latin America, 1981-2010. Country-specific differences in healthcare infrastructure, population structure and population size were controlled for. Between 1981 and 2010, a 1% rise in unemployment was associated with statistically significant deteriorations (peconomics, policymakers should prioritise amelioration of unemployment if population health outcomes are to be optimised. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  9. Towards More Effective Water Quality Governance: A Review of Social-Economic, Legal and Ecological Perspectives and Their Interactions

    Directory of Open Access Journals (Sweden)

    Susanne Wuijts

    2018-03-01

    Full Text Available In this article, social-economic, legal and ecological perspectives on effectiveness of water quality governance and their interactions have been studied. Worldwide, authorities are facing the challenge of restoring and preserving aquatic ecosystems in accordance with the United Nations Sustainable Development Goals (SDG 6. Over the last few decades, governance approaches have often been used to realise these ambitions. To date, scholars have identified that it is difficult to relate governance approaches to water quality improvement and have offered several different explanations for this. Combined with a targeted conceptualisation of the perspectives and their interactions, the systematic literature review demonstrates the gap that exists in the current understanding of these interactions and what their effects are on water quality improvement, especially in regard to the identification of ecological issues and their boundary conditions for the legal framework and the development of measures and follow-up. The review also reveals that the scientific debate is focused on the planning rather than implementation phase. A step forward can be made by supplementing existing analytical frameworks by the interactions between the different perspectives, especially those related to problem definition and the development and realisation of measures.

  10. Compounded effects of chlorinated ethene inhibition on ecological interactions and population abundance in a Dehalococcoides - Dehalobacter coculture.

    Science.gov (United States)

    Lai, Yenjung; Becker, Jennifer G

    2013-02-05

    The development of rational and effective engineered bioremediation approaches for sites contaminated with chlorinated solvents requires a fundamental understanding of the factors limiting the in situ activity of dehalorespiring bacteria. Frequently, multiple dehalorespiring bacteria are present at contaminated sites, particularly when bioaugmentation is applied. The ecological interactions between different dehalorespiring populations can-along with hydrodynamic and other environmental factors-affect their activity and thus the rates and extent of dehalorespiration. An integrated experimental and modeling approach was used to evaluate the ecological interactions between two hydrogenotrophic, dehalorespiring strains. A dual Monod model of dehalorespiration provided a good fit to the chlorinated ethene concentrations measured in a coculture of Dehalococcoides mccartyi 195 and Dehalobacter restrictus growing on tetrachloroethene (PCE) and excess H(2) in a continuous-flow reactor. Inhibition of dehalorespiration by chlorinated ethenes was previously observed in cultures containing Dehalococcoides or Dehalobacter strains. Therefore, inhibition coefficients were estimated for Dhc. mccartyi 195 and Dhb. restrictus. The inhibition effects of PCE and TCE on VC dechlorination by Dhc. mccartyi 195, and of VC on PCE and TCE dechlorination by Dhb. restrictus, were compounded when these strains were grown in coculture, and dehalorespiring population abundance and survival could be accurately predicted only by incorporating these complex interactions into the dual Monod model.

  11. Disease effects on lobster fisheries, ecology, and culture: overview of DAO Special 6.

    Science.gov (United States)

    Behringer, Donald C; Butler, Mark J; Stentiford, Grant D

    2012-08-27

    Lobsters are prized by commercial and recreational fishermen worldwide, and their populations are therefore buffeted by fishery practices. But lobsters also remain integral members of their benthic communities where predator-prey relationships, competitive interactions, and host-pathogen dynamics push and pull at their population dynamics. Although lobsters have few reported pathogens and parasites relative to other decapod crustaceans, the rise of diseases with consequences for lobster fisheries and aquaculture has spotlighted the importance of disease for lobster biology, population dynamics and ecology. Researchers, managers, and fishers thus increasingly recognize the need to understand lobster pathogens and parasites so they can be managed proactively and their impacts minimized where possible. At the 2011 International Conference and Workshop on Lobster Biology and Management a special session on lobster diseases was convened and this special issue of Diseases of Aquatic Organisms highlights those proceedings with a suite of articles focused on diseases discussed during that session.

  12. Assessing population and environmental effects on thermal resistance in Drosophila melanogaster using ecologically relevant assays

    DEFF Research Database (Denmark)

    Overgaard, Johannes; Hoffmann, Ary A; Kristensen, Torsten Nygård

    2011-01-01

    To make laboratory studies of thermal resistance in ectotherms more ecologically relevant, temperature changes that reflect conditions experienced by individuals in nature should be used. Here we describe an assay that is useful for quantifying multiple measures of thermal resistance of individual...... adult flies. We use this approach to assess upper and lower thermal limits and functional thermal scope for Drosophila melanogaster and also show that the method can be used to (1) detect a previously described latitudinal cline for cold tolerance in D. melanogaster populations collected along the east...... thermal environments have wider thermal limits compared to those from the less variable tropics, at least when flies were reared under constant temperature conditions and (4) demonstrate that different measures of cold resistance are often not strongly correlated. Based on our findings, we suggest...

  13. An ecological study for Sri Lanka about health effects of coconut.

    Science.gov (United States)

    Athauda, L K; Wickremasinghe, A R; Kumarendran, B; Kasturiratne, A

    2015-09-01

    An ecological correlation study was conducted to determine the association between consumption of coconut products and cardiovascular disease (CVD) deaths in Sri Lanka. Data on coconut consumption patterns from 1961 to 2006 were abstracted from the FAO database, and mortality data from reports of the Department of Census and Statistics, and UN databases. Correlational and regression analyses were carried out. There was no increase in the per capita consumption of coconut products from 1961 to 2006 (range 54.1-76.2kg/ capita/year). The CVD death rates and the proportionate mortality rate due to CVD increased from 1961 to 2006. CVD death rates were significantly associated with per capita GDP, percentage of urban population, and elderly dependency ratio but not consumption of coconut products after adjusting for the other variables (R2=0.94). The results do not provide evidence at the population level that consumption of coconut products increases mortality due to cardiovascular diseases.

  14. [Ecological regionalization of national cotton fiber quality in China using GGE biplot analysis method].

    Science.gov (United States)

    Xu, Nai Yin; Jin, Shi Qiao; Li, Jian

    2017-01-01

    The distinctive regional characteristics of cotton fiber quality in the major cotton-producing areas in China enhance the textile use efficiency of raw cotton yarn by improving fiber quality through ecological regionalization. The "environment vs. trait" GGE biplot analysis method was adopted to explore the interaction between conventional cotton sub-regions and cotton fiber quality traits based on the datasets collected from the national cotton regional trials from 2011 to 2015. The results showed that the major cotton-producing area in China were divided into four fiber quality ecological regions, namely, the "high fiber quality ecological region", the "low micronaire ecological region", the "high fiber strength and micronaire ecological region", and the "moderate fiber quality ecological region". The high fiber quality ecological region was characterized by harmonious development of cotton fiber length, strength, micronaire value and the highest spinning consistency index, and located in the conventional cotton regions in the upper and lower reaches of Yangtze River Valley. The low micronaire value ecological region composed of the northern and south Xinjiang cotton regions was characterized by low micronaire value, relatively lower fiber strength, and relatively high spinning consistency index performance. The high fiber strength and micronaire value ecological region covered the middle reaches of Yangtze River Valley, Nanxiang Basin and Huaibei Plain, and was prominently characterized by high strength and micronaire value, and moderate performance of other traits. The moderate fiber quality ecological region included North China Plain and Loess Plateau cotton growing regions in the Yellow River Valley, and was characterized by moderate or lower performances of all fiber quality traits. This study effectively applied "environment vs. trait" GGE biplot to regionalize cotton fiber quality, which provided a helpful reference for the regiona-lized cotton growing

  15. Effect of ecological restoration and climate change on ecosystems: a case study in the Three-Rivers Headwater Region, China.

    Science.gov (United States)

    Jiang, Chong; Zhang, Linbo

    2016-06-01

    The Three-Rivers Headwater Region (TRHR) is the headwater of the Yangtze River Basin (YARB), Yellow River Basin (YRB), and Lancang River Basin (LRB); it is known as China's 'Water Tower' owing to its important supply of freshwater. In order to assess ecosystem changes in the TRHR during 2000-2012, we systematically and comprehensively evaluated a combination of model simulation results and actual observational data. The results showed the following: (1) Ecosystem pattern was relatively stable during 2000-2010, with a slight decrease in farmland and desert areas, and a slight increase in grassland and wetland/water-body areas. (2) A warmer and wetter climate, and ecological engineering, caused the vegetation cover and productivity to significantly improve. (3) Precipitation was the main controlling factor for streamflow. A significant increase in precipitation during 2000-2012 resulted in an obvious increase in annual and seasonal streamflow. Glacier melting also contributed to the streamflow increase. (4) The total amount of soil conservation increased slightly from 2000 to 2012. The increase in precipitation caused rainfall erosivity to increase, which enhanced the intensity of soil erosion. The decrease in wind speed decreased wind erosion and the frequency of sandstorms. (5) The overall habitat quality in the TRHR was stable between 2000 and 2010, and the spatial pattern exhibited obvious heterogeneity. In some counties that included nature reserves, habitat quality was slightly higher in 2010 than in 2000, which reflected the effectiveness of the ecological restoration. Overall, the aforementioned ecosystem changes are the combined results of ecological restoration and climate change, and they are likely a local and temporary improvement, rather than a comprehensive and fundamental change. Therefore, more investments and efforts are needed to preserve natural ecosystems.

  16. Ecological risk estimation

    International Nuclear Information System (INIS)

    Bartell, S.M.; Gardner, R.H.; O'Neill, R.V.

    1992-01-01

    Ecological risk assessment, the process that evaluates the likelihood that adverse ecological effects may occur or are occurring as a result of exposure to one or more stressors, is being developed by the US EPA as a tool for decision making. This book presents one approach to risk assessment-that of applying laboratory toxicity data within an ecosystem model to predict the potential ecological consequences of toxic chemicals. Both Standard Water Column Model (SWACOM), using zooplankton and fish, and Monte Carlo simulations are discussed in detail, along with quantitative explanations for many responses. Simplifying assumptions are explicitly presented. The final chapter discusses strengths, weaknesses, and future directions of the approach. The book is appropriate for anyone who does or uses ecological risk assessment methodologies

  17. Effects of the hippopotamus on the chemistry and ecology of a changing watershed.

    Science.gov (United States)

    Stears, Keenan; McCauley, Douglas J; Finlay, Jacques C; Mpemba, James; Warrington, Ian T; Mutayoba, Benezeth M; Power, Mary E; Dawson, Todd E; Brashares, Justin S

    2018-05-29

    Cross-boundary transfers of nutrients can profoundly shape the ecology of recipient systems. The common hippopotamus, Hippopotamus amphibius , is a significant vector of such subsidies from terrestrial to river ecosystems. We compared river pools with high and low densities of H. amphibius to determine how H. amphibius subsidies shape the chemistry and ecology of aquatic communities. Our study watershed, like many in sub-Saharan Africa, has been severely impacted by anthropogenic water abstraction reducing dry-season flow to zero. We conducted observations for multiple years over wet and dry seasons to identify how hydrological variability influences the impacts of H. amphibius During the wet season, when the river was flowing, we detected no differences in water chemistry and nutrient parameters between pools with high and low densities of H. amphibius Likewise, the diversity and abundance of fish and aquatic insect communities were indistinguishable. During the dry season, however, high-density H. amphibiu s pools differed drastically in almost all measured attributes of water chemistry and exhibited depressed fish and insect diversity and fish abundance compared with low-density H. amphibius pools. Scaled up to the entire watershed, we estimate that H. amphibius in this hydrologically altered watershed reduces dry-season fish abundance and indices of gamma-level diversity by 41% and 16%, respectively, but appears to promote aquatic invertebrate diversity. Widespread human-driven shifts in hydrology appear to redefine the role of H. amphibius , altering their influence on ecosystem diversity and functioning in a fashion that may be more severe than presently appreciated.

  18. Ecological macroeconomics

    DEFF Research Database (Denmark)

    Røpke, Inge

    2013-01-01

    by a more theoretical debate and increased interaction between the heterodox schools of ecological economics and post-Keynesian economics. In addition, both the degrowth community and the research community organized around sustainable transitions of socio-technical systems have contributed to discussions...... on how to reconcile environmental and social concerns. Based on this broad variety of pieces in a jigsaw puzzle, a new ecological macroeconomics is emerging, but the contours are still vague. This chapter seeks to outline some of this topography and to add a few pieces of its own by highlighting the need...... to shift resources from consumption to investment and describing the role of consumer-citizens in such a change. The chapter starts by identifying the problems and challenges for an ecological macroeconomics. The next section outlines some of the shortcomings of traditional macroeconomics...

  19. A modelling approach to evaluating the effectiveness of Ecological Focus Areas: the case of the European brown hare

    DEFF Research Database (Denmark)

    Langhammer, Maria; Grimm, Volker; Putz, Sandro

    2016-01-01

    and Man Simulation System (ALMaSS), an established simulation system that has been used to simulate a wide range of farmland species relevant to biodiversity. We analysed the benefits of seven greening scenarios for the European brown hare (Lepus europaeus), which has been in widespread decline throughout......With the current implementation of the Common Agricultural Policy (CAP) for 2014–2020, the European Commission wants to move towards “greener” farming practices in the European Union. Therefore, the EU funds both obligatory measures, such as Ecological Focus Areas (EFAs) through the Green Direct...... of each type was increased separately up to 5% of the area in three Danish landscapes, which are characterised by low hare densities. The effects on female and yearling abundance were observed over a period of 30 years. All greening scenarios had significant positive effects on hare populations...

  20. Environmental study of the Wairakei Power Plant. [Effects of hydroelectric power plant on ecology of Waikato River Basin, New Zealand

    Energy Technology Data Exchange (ETDEWEB)

    Axtmann, R C

    1974-12-01

    Physical, chemical, biological, ecological, and aesthetic aspects of the Wairakei Power Plant are examined, in varying detail, but with primary emphasis on the chemical and thermal effluents. When flows are average or higher in the Waikato River, the Plant's environmental effects are not overly severe. However, operating requirements for the Waikato Hydro-electric System are such that the Plant sporadically produces wastes that may affect the human and natural environment adversely. These adverse effects are not presently too serious, but suggestions are made for improving the Plant's overall environmental performance. Although the point is not discussed in detail, it is clear from the results of the study that any additional thermal plants on the Waikato could strain the river's absorptive capacities severely, unless alternative disposal techniques are used for the various effluents.

  1. Microbiological aspects of an in situ model to study effects of antimicrobial agents on dental plaque ecology.

    Science.gov (United States)

    Giertsen, E; Guggenheim, B; Thurnheer, T; Gmür, R

    2000-10-01

    This study validates an in situ model for ecological studies of dental plaque exposed to various antimicrobial agents with different modes of action on plaque bacteria. Eleven subjects wore two acrylic appliances, each containing two bovine enamel discs, during two 1-wk test periods. Using a split-mouth crossover design, the appliances were dipped twice daily for 1 min into water (control; treatment A), fluoride (26.3 mM NaF; B), zinc acetate (20.0 mM; C), or fluoride plus zinc acetate (D). Four of the subjects used also chlorhexidine diacetate (2.2 mM; E) and chlorhexidine plus fluoride (F). At the end of each period, plaque was collected from the discs, after which the microbiota were analyzed by culture, automated quantitative immunofluorescence, and a viability fluorescence stain. As compared to control, treatments B, C, and D resulted in a significant reduction of individual taxa as detected by immunofluorescence, whereas similar bacterial viability and total bacterial numbers were observed. In contrast, chlorhexidine significantly reduced bacterial viability, total cell numbers, and the abundance of most of the enumerated taxa. We conclude that this in situ model is well suited to study effects of antimicrobial agents on dental plaque ecology. Combined with viability testing, immunofluorescence is obviously superior to culture in detecting taxa-specific shifts caused by antimicrobial agents.

  2. Quantifying the effect of ecological restoration on soil erosion in China's Loess Plateau region: an application of the MMF approach.

    Science.gov (United States)

    Li, Changbin; Qi, Jiaguo; Feng, Zhaodong; Yin, Runsheng; Guo, Biyun; Zhang, Feng; Zou, Songbing

    2010-03-01

    Land degradation due to erosion is one of the most serious environmental problems in China. To reduce land degradation, the government has taken a number of conservation and restoration measures, including the Sloping Land Conversion Program (SLCP), which was launched in 1999. A logical question is whether these measures have reduced soil erosion at the regional level. The objective of this article is to answer this question by assessing soil erosion dynamics in the Zuli River basin in the Loess Plateau of China from 1999 to 2006. The MMF (Morgan, Morgan and Finney) model was used to simulate changes in runoff and soil erosion over the period of time during which ecological restoration projects were implemented. Some model variables were derived from remotely sensed images to provide improved land surface representation. With an overall accuracy rate of 0.67, our simulations show that increased ground vegetation cover, especially in forestlands and grasslands, has reduced soil erosion by 38.8% on average from 1999 to 2006. During the same time period, however, the change in rainfall pattern has caused a 13.1% +/- 4.3% increase in soil erosion, resulting in a net 25.7% +/- 8.5% reduction in soil erosion. This suggests that China's various ecological restoration efforts have been effective in reducing soil loss.

  3. Effects of Wind Energy Development on Nesting Ecology of Greater Prairie-Chickens in Fragmented Grasslands

    Science.gov (United States)

    McNew, Lance B; Hunt, Lyla M; Gregory, Andrew J; Wisely, Samantha M; Sandercock, Brett K

    2014-01-01

    Wind energy is targeted to meet 20% of U.S. energy needs by 2030, but new sites for development of renewable energy may overlap with important habitats of declining populations of grassland birds. Greater Prairie-Chickens (Tympanuchus cupido) are an obligate grassland bird species predicted to respond negatively to energy development. We used a modified before–after control–impact design to test for impacts of a wind energy development on the reproductive ecology of prairie-chickens in a 5-year study. We located 59 and 185 nests before and after development, respectively, of a 201 MW wind energy facility in Greater Prairie-Chicken nesting habitat and assessed nest site selection and nest survival relative to proximity to wind energy infrastructure and habitat conditions. Proximity to turbines did not negatively affect nest site selection (β = 0.03, 95% CI = −1.2–1.3) or nest survival (β = −0.3, 95% CI = −0.6–0.1). Instead, nest site selection and survival were strongly related to vegetative cover and other local conditions determined by management for cattle production. Integration of our project results with previous reports of behavioral avoidance of oil and gas facilities by other species of prairie grouse suggests new avenues for research to mitigate impacts of energy development. Efectos del Desarrollo de la Energía Eólica sobre la Ecología de Anidación de Gallinas de la Gran Pradera en Pastizales Fragmentados Resumen Se calcula que la energía eólica aportará el 20% de las necesidades energéticas de los Estados Unidos para el 2030, pero nuevos sitios para el desarrollo de energía renovable pueden traslaparse con hábitats importantes de poblaciones declinantes de aves de pastizal. La gallina de la Gran Pradera (Tympanuchus cupido) es una especie de ave obligada de pastizal que se pronostica responderá negativamente al desarrollo energético. Usamos un diseño ADCI modificado para probar los impactos del desarrollo de la energía e

  4. Environmental and ecological conditions at Arctic breeding sites have limited effects on true survival rates of adult shorebirds

    Science.gov (United States)

    Weiser, Emily L.; Lanctot, Richard B.; Brown, Stephen C.; Gates, H. River; Bentzen, Rebecca L.; Bêty, Joël; Boldenow, Megan L.; English, Willow B.; Franks, Samantha E.; Koloski, Laura; Kwon, Eunbi; Lamarre, Jean-Francois; Lank, David B.; Liebezeit, Joseph R.; McKinnon, Laura; Nol, Erica; Rausch, Jennie; Saalfeld, Sarah T.; Senner, Nathan R.; Ward, David H.; Woodard, Paul F.; Sandercock, Brett K.

    2018-01-01

    Many Arctic shorebird populations are declining, and quantifying adult survival and the effects of anthropogenic factors is a crucial step toward a better understanding of population dynamics. We used a recently developed, spatially explicit Cormack–Jolly–Seber model in a Bayesian framework to obtain broad-scale estimates of true annual survival rates for 6 species of shorebirds at 9 breeding sites across the North American Arctic in 2010–2014. We tested for effects of environmental and ecological variables, study site, nest fate, and sex on annual survival rates of each species in the spatially explicit framework, which allowed us to distinguish between effects of variables on site fidelity versus true survival. Our spatially explicit analysis produced estimates of true survival rates that were substantially higher than previously published estimates of apparent survival for most species, ranging from S = 0.72 to 0.98 across 5 species. However, survival was lower for the arcticolasubspecies of Dunlin (Calidris alpina arcticola; S = 0.54), our only study taxon that migrates through the East Asian–Australasian Flyway. Like other species that use that flyway, arcticola Dunlin could be experiencing unsustainably low survival rates as a result of loss of migratory stopover habitat. Survival rates of our study species were not affected by timing of snowmelt or summer temperature, and only 2 species showed minor variation among study sites. Furthermore, although previous reproductive success, predator abundance, and the availability of alternative prey each affected survival of one species, no factors broadly affected survival across species. Overall, our findings of few effects of environmental or ecological variables suggest that annual survival rates of adult shorebirds are generally robust to conditions at Arctic breeding sites. Instead, conditions at migratory stopovers or overwintering sites might be driving adult survival rates and should be the

  5. Characterizing effects of hydropower plants on sub-daily flow regimes

    Science.gov (United States)

    Bejarano, María Dolores; Sordo-Ward, Álvaro; Alonso, Carlos; Nilsson, Christer

    2017-07-01

    A characterization of short-term changes in river flow is essential for understanding the ecological effects of hydropower plants, which operate by turning the turbines on or off to generate electricity following variations in the market demand (i.e., hydropeaking). The goal of our study was to develop an approach for characterizing the effects of hydropower plant operations on within-day flow regimes across multiple dams and rivers. For this aim we first defined ecologically meaningful metrics that provide a full representation of the flow regime at short time scales from free-flowing rivers and rivers exposed to hydropeaking. We then defined metrics that enable quantification of the deviation of the altered short-term flow regime variables from those of the unaltered state. The approach was successfully tested in two rivers in northern Sweden, one free-flowing and another regulated by cascades of hydropower plants, which were additionally classified based on their impact on short-term flows in sites of similar management. The largest differences between study sites corresponded to metrics describing sub-daily flow magnitudes such as amplitude (i.e., difference between the highest and the lowest hourly flows) and rates (i.e., rise and fall rates of hourly flows). They were closely followed by frequency-related metrics accounting for the numbers of within-day hourly flow patterns (i.e., rises, falls and periods of stability of hourly flows). In comparison, between-site differences for the duration-related metrics were smallest. In general, hydropeaking resulted in higher within-day flow amplitudes and rates and more but shorter periods of a similar hourly flow patterns per day. The impacted flow feature and the characteristics of the impact (i.e., intensity and whether the impact increases or decreases whatever is being described by the metric) varied with season. Our approach is useful for catchment management planning, defining environmental flow targets

  6. Effect of selenium on its content in milk and performance of dairy cows in ecological farming

    Directory of Open Access Journals (Sweden)

    Pavel Horký

    2015-08-01

    Full Text Available Currently, the ecological farming is increasingly spread in the European Union. The aim of this relatively young farming method is a friendly approach to agricultural production with an emphasis to deliver healthy raw materials and food to final consumer. Selenium is included in an essential trace micronutrients which are necessary for the proper process of physiological reactions. It is a part of glutathione peroxidase, which is a powerful antioxidant. At present,  selenium-deficiency can occur in feed and food in central Europe. Selenium deficiency is one cause of the higher occurrence of cardiovascular diseases. The aim of the experiment was to study whether the addition of selenium to the diet of dairy cows in ecological farming can increase its concentration in milk and affect quantitative (milk yield and quality (content of protein, fat, lactose, somatic cells and urea milk indicators. The experiment included twenty cows of Holstein breed. The first experimental group of cows (n = 10 was fed with selenium in an amount of 0.3 mg.kg-1 (as selenomethionine in the feed dose. The control group (n = 10 was not fed with the increased selenium in the feed dose. The basic feed dose contained 0.17 mg of Se/kg in the diet. For dairy cows, daily intake was of 20.5 kg of dry matter feed. The duration of the experiment was set at 45 days. The selenium concentration in milk was measured from 0.13 to 0.15 µg.mL-1 in the experimental group of cows during the evaluation. The control group of cows without the addition of selenium to the diet showed a selenium concentration below the detection limit. During the experiment, milk yield, lactose, fat and protein were not affected. A significant decrease (p <0.05 of somatic cells by 58% occurred in milk in the experimental group. The amount of urea was significantly lower in both groups in the experimental (by 52%; p <0.05 and control (50%; p <0.05. These results show that the addition of selenium may increase

  7. Effective Management of Ocean Biogeochemistry and Ecological Data: the BCO-DMO Story

    Science.gov (United States)

    Chandler, C. L.; Groman, R. C.; Allison, M. D.; Wiebe, P. H.; Glover, D. M.; Gegg, S. R.

    2012-04-01

    Data availability expectations of the research community, environmental management decision makers, and funding agency representatives are changing. Consequently, data management practices in many science communities are changing as well. In an effort to improve access to data generated by ocean biogeochemistry and ecological researchers funded by the United States (US) National Science Foundation (NSF) Division of Ocean Sciences (OCE), the Biological and Chemical Oceanography Data Management Office (BCO-DMO) was created in late 2006. Currently, the main BCO-DMO objective is to ensure availability of data resulting from select OCE and Office of Polar Programs (OPP) research awards granted by the US NSF. An important requirement for the BCO-DMO data management system is that it provides open access to data that are supported by sufficient metadata to enable data discovery and accurate reuse. The office manages and serves all types of oceanographic data (in situ, experimental, model results) generated during the research process and contributed by the originating investigators from large national programs and medium-sized collaborative research projects, as well as researchers with single investigator awards. BCO-DMO staff members have made strategic use of standards and use of terms from controlled vocabularies while balancing the need to maintain flexible data ingest systems that accommodate the heterogeneous nature of ocean biogeochemistry and ecological research data. Many of the discrete ocean biogeochemistry data sets managed by BCO-DMO are still acquired manually, often with prototype sensor systems. Data sets such as these that are not "born-digital" present a significant management challenge. Use of multiple levels of term-mappings and development of an ontology has enabled BCO-DMO to incorporate a semantically enabled faceted search into the data access system that will improve data access through enhanced data discovery. BCO-DMO involves an ongoing

  8. Myxomatosis: population dynamics of rabbits (Oryctolagus cuniculus Linnaeus, 1758) and ecological effects in the United Kingdom.

    Science.gov (United States)

    Flowerdew, J R; Trout, R C; Ross, J

    1992-12-01

    In 1953-1955, myxomatosis spread among rabbits (Oryctolagus cuniculus) in the United Kingdom, causing 99% mortality. Subsequently, there was a gradual increase in rabbit numbers. By 1955, the Ministry of Agriculture, Fisheries and Food (MAFF) had already found attenuated strains of myxoma virus. By 1970, genetic resistance had appeared. In the 1970s, mortality declined to 47-69% with only approximately 25% of rabbits infected, giving a field mortality of 12-19%. However, myxomatosis is persistent, generally showing a major prevalence peak in autumn and often a minor peak in spring. An eight-year MAFF experiment in which prevalence of the disease was artificially reduced indicates that myxomatosis remains a significant factor in population regulation. After rabbit numbers fell in the 1950s, important ecological changes took place: vegetation altered due to reduced grazing pressure, predators were affected by the reduction of a major prey species and these changes also affected many other animals. Currently, rabbit numbers have returned to approximately one-third of pre-myxomatosis levels and this is causing damage to farm and conservation habitats.

  9. Effects of climate change on ecological disturbance in the northern Rockies

    Science.gov (United States)

    Loehman, Rachel A.; Bentz, Barbara J.; DeNitto, Gregg A.; Keane, Robert E.; Manning, Mary E.; Duncan, Jacob P.; Egan, Joel M.; Jackson, Marcus B.; Kegley, Sandra; Lockman, I. Blakey; Pearson, Dean E.; Powell, James A.; Shelly, Steve; Steed, Brytten E.; Zambino, Paul J.; Halofsky, Jessica E.; Peterson, David L.

    2018-01-01

    Disturbances alter ecosystem, community, or population structure and change elements of the biological and/or physical environment. Climate changes can alter the timing, magnitude, frequency, and duration of disturbance events, as well as the interactions of disturbances on a landscape, and climate change may already be affecting disturbance events and regimes. Interactions among disturbance regimes, such as the cooccurrence in space and time of bark beetle outbreaks and wildfires, can result in highly visible, rapidly occurring, and persistent changes in landscape composition and structure. Understanding how altered disturbance patterns and multiple disturbance interactions might result in novel and emergent landscape behaviors is critical for addressing climate change impacts and for designing land management strategies that are appropriate for future climates This chapter describes the ecology of important disturbance regimes in the Northern Rockies region, and potential shifts in these regimes as a consequence of observed and projected climate change. We summarize five disturbance types present in the Northern Rockies that are sensitive to a changing climate--wildfires, bark beetles, white pine blister rust (Cronartium ribicola), other forest diseases, and nonnative plant invasions—and provide information that can help managers anticipate how, when, where, and why climate changes may alter the characteristics of disturbance regimes.

  10. Fitness effects of a selfish gene (the Mus t complex) are revealed in an ecological context.

    Science.gov (United States)

    Carroll, Lara S; Meagher, Shawn; Morrison, Linda; Penn, Dustin J; Potts, Wayne K

    2004-06-01

    In wild house mice, genes linked to the t transmission distortion complex cause meiotic drive by sabotaging wild-type gametes. The t complex is consequently inherited at frequencies higher than 90%. Yet, for unclear reasons, in wild mouse populations this selfish DNA is found at frequencies much lower than expected. Here, we examine selection on the t complex in 10 seminatural populations of wild mice based on data from 234 founders and nearly 2000 progeny. Eight of the 10 populations decreased in t frequency over one generation, and the overall frequency of t haplotypes across all 10 populations was 48.5% below expectations based on transmission distortion and 34.3% below Mendelian (or Hardy-Weinberg) expectations. Behavioral and reproductive data were collected for 10 months for each population, and microsatellite genotyping was performed on seven of the populations to determine parentage. These combined data show t-associated fitness declines in both males and females. This is the first study to show evidence for a reduction in the ability of +/t males to maintain territories. Because females tend to mate with dominant males, impairment of territorial success can explain much of the selection against t observed in our populations. In nature, selection against heterozygote carriers of the t complex helps solve the puzzlingly low t frequencies found in wild populations. This ecological approach for determining fitness consequences of genetic variants has broad application for the discovery of gene function in general.

  11. What are the psychological effects of ecological information in the daily newspaper?

    Energy Technology Data Exchange (ETDEWEB)

    Nerb, J.; Spada, H. [Freiburg Univ., Dept. of Psychology (Germany)

    1998-07-01

    Full text of publication follows: Lay people's evaluation of environmental risks is often based on mass media descriptions of single disastrous events rather than on probability information about potential damages (Slovic, 1997). We analyzed the cognitive and emotional reactions of people reading those newspaper reports and found an intuitive, spontaneous, and schema-based evaluation process that entails a coherent perception and appraisal of the causes of the respective events. As an aid in understanding how ecological information and its presentation influences cognition emotion, and behavior, the computational model (ITERA, short for Intuitive Thinking in Environmental Risk Appraisal) is proposed. The model is implemented by means of a parallel constraint satisfaction network (cf. Holyoak and Thagard, 1995). ITERA provides an explanation and prediction of the cognitive evaluation of environmental problems, the development of distinct emotions (anger and sadness), and the resulting action tendencies (e.g., boycotting the company which is seen responsible for the environmental damage). The model is consistent with several theoretical and empirical results from psychological research, and most of its novel predictions could be validated in own experimental work. Beside its significance for risk perception research, the model provides a way to evaluate several common risk-communication and crisis-response strategies (Coombs, 1995). (authors)

  12. Effects of wind energy development on nesting ecology of greater prairie-chickens in fragmented grasslands.

    Science.gov (United States)

    McNew, Lance B; Hunt, Lyla M; Gregory, Andrew J; Wisely, Samantha M; Sandercock, Brett K

    2014-08-01

    Wind energy is targeted to meet 20% of U.S. energy needs by 2030, but new sites for development of renewable energy may overlap with important habitats of declining populations of grassland birds. Greater Prairie-Chickens (Tympanuchus cupido) are an obligate grassland bird species predicted to respond negatively to energy development. We used a modified before-after control-impact design to test for impacts of a wind energy development on the reproductive ecology of prairie-chickens in a 5-year study. We located 59 and 185 nests before and after development, respectively, of a 201 MW wind energy facility in Greater Prairie-Chicken nesting habitat and assessed nest site selection and nest survival relative to proximity to wind energy infrastructure and habitat conditions. Proximity to turbines did not negatively affect nest site selection (β = 0.03, 95% CI = -1.2-1.3) or nest survival (β = -0.3, 95% CI = -0.6-0.1). Instead, nest site selection and survival were strongly related to vegetative cover and other local conditions determined by management for cattle production. Integration of our project results with previous reports of behavioral avoidance of oil and gas facilities by other species of prairie grouse suggests new avenues for research to mitigate impacts of energy development. © 2014 The Authors. Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology.

  13. What are the psychological effects of ecological information in the daily newspaper?

    International Nuclear Information System (INIS)

    Nerb, J.; Spada, H.

    1998-01-01

    Full text of publication follows: Lay people's evaluation of environmental risks is often based on mass media descriptions of single disastrous events rather than on probability information about potential damages (Slovic, 1997). We analyzed the cognitive and emotional reactions of people reading those newspaper reports and found an intuitive, spontaneous, and schema-based evaluation process that entails a coherent perception and appraisal of the causes of the respective events. As an aid in understanding how ecological information and its presentation influences cognition emotion, and behavior, the computational model (ITERA, short for Intuitive Thinking in Environmental Risk Appraisal) is proposed. The model is implemented by means of a parallel constraint satisfaction network (cf. Holyoak and Thagard, 1995). ITERA provides an explanation and prediction of the cognitive evaluation of environmental problems, the development of distinct emotions (anger and sadness), and the resulting action tendencies (e.g., boycotting the company which is seen responsible for the environmental damage. The model is consistent with several theoretical and empirical results from psychological research, and most of its novel predictions could be validated in own experimental work. Beside its significance for risk perception research, the model provides a way to evaluate several common risk-communication and crisis-response strategies (Coombs, 1995). (authors)

  14. Effects of national ecological restoration projects on carbon sequestration in China from 2001 to 2010.

    Science.gov (United States)

    Lu, Fei; Hu, Huifeng; Sun, Wenjuan; Zhu, Jiaojun; Liu, Guobin; Zhou, Wangming; Zhang, Quanfa; Shi, Peili; Liu, Xiuping; Wu, Xing; Zhang, Lu; Wei, Xiaohua; Dai, Limin; Zhang, Kerong; Sun, Yirong; Xue, Sha; Zhang, Wanjun; Xiong, Dingpeng; Deng, Lei; Liu, Bojie; Zhou, Li; Zhang, Chao; Zheng, Xiao; Cao, Jiansheng; Huang, Yao; He, Nianpeng; Zhou, Guoyi; Bai, Yongfei; Xie, Zongqiang; Tang, Zhiyao; Wu, Bingfang; Fang, Jingyun; Liu, Guohua; Yu, Guirui

    2018-04-17

    The long-term stressful utilization of forests and grasslands has led to ecosystem degradation and C loss. Since the late 1970s China has launched six key national ecological restoration projects to protect its environment and restore degraded ecosystems. Here, we conducted a large-scale field investigation and a literature survey of biomass and soil C in China's forest, shrubland, and grassland ecosystems across the regions where the six projects were implemented (∼16% of the country's land area). We investigated the changes in the C stocks of these ecosystems to evaluate the contributions of the projects to the country's C sink between 2001 and 2010. Over this decade, we estimated that the total annual C sink in the project region was 132 Tg C per y (1 Tg = 10 12 g), over half of which (74 Tg C per y, 56%) was attributed to the implementation of the projects. Our results demonstrate that these restoration projects have substantially contributed to CO 2 mitigation in China.

  15. Nitrogen deposition effects on Mediterranean-type ecosystems: An ecological assessment

    Energy Technology Data Exchange (ETDEWEB)

    Ochoa-Hueso, Raul, E-mail: raul.ochoa@ccma.csic.es [Department of Plant Physiology and Ecology, Centro de Ciencias Medioambientales, Consejo Superior de Investigaciones Cientificas, C/Serrano 115 Dpdo., 28006 Madrid (Spain); Allen, Edith B. [Department of Botany and Plant Sciences and Center for Conservation Biology, University of California, Riverside, CA 92521 (United States); Branquinho, Cristina; Cruz, Cristina; Dias, Teresa [Universidade de Lisboa, Faculdade de Ciencias, Centro de Biologia Ambiental, Campo Grande, Bloco C4, 1749-016 Lisboa (Portugal); Fenn, Mark E. [US Department of Agriculture (USDA) Forest Service, Pacific Southwest Research Station, 4955 Canyon Crest Drive, Riverside, CA 92507 (United States); Manrique, Esteban [Department of Plant Physiology and Ecology, Centro de Ciencias Medioambientales, Consejo Superior de Investigaciones Cientificas, C/Serrano 115 Dpdo., 28006 Madrid (Spain); Perez-Corona, M. Esther [Department of Ecology, Faculty of Biology, Universidad Complutense de Madrid, C/Jose Antonio Novais 2, 28040 Madrid (Spain); Sheppard, Lucy J. [Centre of Ecology and Hydrology, Bush Estate, Penicuik EH26 0QB (United Kingdom); Stock, William D. [Centre for Ecosystem Management, School of Natural Sciences, Edith Cowan University, 100 Joondalup Drive, Joondalup, Perth, WA 6027 (Australia)

    2011-10-15

    We review the ecological consequences of N deposition on the five Mediterranean regions of the world. Seasonality of precipitation and fires regulate the N cycle in these water-limited ecosystems, where dry N deposition dominates. Nitrogen accumulation in soils and on plant surfaces results in peaks of availability with the first winter rains. Decoupling between N flushes and plant demand promotes losses via leaching and gas emissions. Differences in P availability may control the response to N inputs and susceptibility to exotic plant invasion. Invasive grasses accumulate as fuel during the dry season, altering fire regimes. California and the Mediterranean Basin are the most threatened by N deposition; however, there is limited evidence for N deposition impacts outside of California. Consequently, more research is needed to determine critical loads for each region and vegetation type based on the most sensitive elements, such as changes in lichen species composition and N cycling. - Highlights: > N deposition impacts are understudied in Mediterranean ecosystems out of California. > Dry N deposition is dominant and N flushes are common after rainless periods. > Water availability and P fertility regulate ecosystem responses to N deposition. > Research is needed to determine critical loads for each region and vegetation type. - Nitrogen deposition threatens the Mediterranean regions of the world.

  16. Nitrogen deposition effects on Mediterranean-type ecosystems: An ecological assessment

    International Nuclear Information System (INIS)

    Ochoa-Hueso, Raul; Allen, Edith B.; Branquinho, Cristina; Cruz, Cristina; Dias, Teresa; Fenn, Mark E.; Manrique, Esteban; Perez-Corona, M. Esther; Sheppard, Lucy J.; Stock, William D.

    2011-01-01

    We review the ecological consequences of N deposition on the five Mediterranean regions of the world. Seasonality of precipitation and fires regulate the N cycle in these water-limited ecosystems, where dry N deposition dominates. Nitrogen accumulation in soils and on plant surfaces results in peaks of availability with the first winter rains. Decoupling between N flushes and plant demand promotes losses via leaching and gas emissions. Differences in P availability may control the response to N inputs and susceptibility to exotic plant invasion. Invasive grasses accumulate as fuel during the dry season, altering fire regimes. California and the Mediterranean Basin are the most threatened by N deposition; however, there is limited evidence for N deposition impacts outside of California. Consequently, more research is needed to determine critical loads for each region and vegetation type based on the most sensitive elements, such as changes in lichen species composition and N cycling. - Highlights: → N deposition impacts are understudied in Mediterranean ecosystems out of California. → Dry N deposition is dominant and N flushes are common after rainless periods. → Water availability and P fertility regulate ecosystem responses to N deposition. → Research is needed to determine critical loads for each region and vegetation type. - Nitrogen deposition threatens the Mediterranean regions of the world.

  17. Aspen Ecology in Rocky Mountain National Park: Age Distribution, Genetics, and the Effects of Elk Herbivory

    Energy Technology Data Exchange (ETDEWEB)

    Tuskan, Gerald A [ORNL; Yin, Tongming [ORNL

    2008-10-01

    Lack of aspen (Populus tremuloides) recruitment and canopy replacement of aspen stands that grow on the edges of grasslands on the low-elevation elk (Cervus elaphus) winter range of Rocky Mountain National Park (RMNP) in Colorado has been a cause of concern for more than 70 years (Packard, 1942; Olmsted, 1979; Stevens, 1980; Hess, 1993; R.J. Monello, T.L. Johnson, and R.G. Wright, Rocky Mountain National Park, 2006, written commun.). These aspen stands are a significant resource since they are located close to the park's road system and thus are highly visible to park visitors. Aspen communities are integral to the ecological structure of montane and subalpine landscapes because they contain high native species richness of plants, birds, and butterflies (Chong and others, 2001; Simonson and others, 2001; Chong and Stohlgren, 2007). These low-elevation, winter range stands also represent a unique component of the park's plant community diversity since most (more than 95 percent) of the park's aspen stands grow in coniferous forest, often on sheltered slopes and at higher elevations, while these winter range stands are situated on the low-elevation ecotone between the winter range grasslands and some of the park's drier coniferous forests.

  18. Research on the Enhancement Effects of Using Ecological Principles in Managing the Lifecycle of Industrial Land

    Directory of Open Access Journals (Sweden)

    Libin Guo

    2018-06-01

    Full Text Available This paper introduces a performance level concept for industrial land use. The performance level concept uses ecological principles to evaluate index systems for industrial land. We used this concept to integrate local economics, land use, development potential, environmental health and ecosystem management with innovation, harmony, floral preservation, and shared land use. The concept helps promote the efficient use of industrial land and the sustainable use of land resources. We used the chemical medicine manufacturing industry in Chongqing Changshou Economic and Technological Development Zone as a case study. We selected eight companies for analysis and calculated an industrial land performance level for each company. We created three industrial land performance levels: growth potential type, positive development type, and inefficient recession type. To determine economic development and land sustainability, we applied administrative, economic, legal and technical measures to evaluate the entire lifecycle of industrial land. This lifecycle included preliminary project audit access, mid-period dynamic supervision and post land exit management. We conclude by proposing measures to mitigate environmental harm occurring from the intensive use of land for industrial use.

  19. Effect of infrastructure design on commons dilemmas in social-ecological system dynamics.

    Science.gov (United States)

    Yu, David J; Qubbaj, Murad R; Muneepeerakul, Rachata; Anderies, John M; Aggarwal, Rimjhim M

    2015-10-27

    The use of shared infrastructure to direct natural processes for the benefit of humans has been a central feature of human social organization for millennia. Today, more than ever, people interact with one another and the environment through shared human-made infrastructure (the Internet, transportation, the energy grid, etc.). However, there has been relatively little work on how the design characteristics of shared infrastructure affect the dynamics of social-ecological systems (SESs) and the capacity of groups to solve social dilemmas associated with its provision. Developing such understanding is especially important in the context of global change where design criteria must consider how specific aspects of infrastructure affect the capacity of SESs to maintain vital functions in the face of shocks. Using small-scale irrigated agriculture (the most ancient and ubiquitous example of public infrastructure systems) as a model system, we show that two design features related to scale and the structure of benefit flows can induce fundamental changes in qualitative behavior, i.e., regime shifts. By relating the required maintenance threshold (a design feature related to infrastructure scale) to the incentives facing users under different regimes, our work also provides some general guidance on determinants of robustness of SESs under globalization-related stresses.

  20. Ultrafine ash aerosols from coal combustion: Characterization and health effects

    Energy Technology Data Exchange (ETDEWEB)

    William P. Linak; Jong-Ik Yoo; Shirley J. Wasson; Weiyan Zhu; Jost O.L. Wendt; Frank E. Huggins; Yuanzhi Chen; Naresh Shah; Gerald P. Huffman; M. Ian Gilmour [US Environmental Protection Agency, Research Triangle Park, NC (United States). National Risk Management Research Laboratory

    2007-07-01

    Ultrafine coal fly-ash particles withdiameters less than 0.5 {mu}m typically comprise less than 1% of the total fly-ash mass. This paper reports research focused on both characterization and health effects of primary ultrafine coal ash aerosols alone. Ultrafine, fine, and coarse ash particles were segregated and collected from a coal burned in a 20 kW laboratory combustor and two additional coals burned in an externally heated drop tube furnace. Extracted samples from both combustors were characterized by transmission electron microscopy (TEM), wavelength dispersive X-ray fluorescence(WD-XRF) spectroscopy, Moessbauer spectroscopy, and X-ray absorption fine structure (XAFS) spectroscopy. Pulmonary inflammation was characterized by albumin concentrations in mouse lung lavage fluid after instillation of collected particles in saline solutions and a single direct inhalation exposure. Results indicate that coal ultrafine ash sometimes contains significant amounts of carbon, probably soot originating from coal tar volatiles, depending on coal type and combustion device. Surprisingly, XAFS results revealed the presence of chromium and thiophenic sulfur in the ultrafine ash particles. The instillation results suggested potential lung injury, the severity of which could be correlated with the carbon (soot) content of the ultrafines. This increased toxicity is consistent with theories in which the presence of carbon mediates transition metal (i.e., Fe) complexes, as revealed in this work by TEM and XAFS spectroscopy, promoting reactive oxygenspecies, oxidation-reduction cycling, and oxidative stress. 24 refs., 7 figs.

  1. Characterizing the thermal effects of High Energy Arc Faults

    Energy Technology Data Exchange (ETDEWEB)

    Putorti, Anthony; Bareham, Scott; Praydis, Joseph Jr. [National Institute of Standards and Technology (NIST), Gaithersburg, MD (United States); Melly, Nicholas B. [U.S. Nuclear Regulatory Commission (NRC), Washington, DC (United States)

    2015-12-15

    International and domestic operating experience involving High Energy Arc Faults (HEAF) in Nuclear Power Plant (NPP) electrical power systems have demonstrated the potential to cause extensive damage to electrical components and distribution systems along with damage to adjacent equipment and cables. An international study by the Committee on the Safety of Nuclear Installations (CSNI) gOECD Fire Project. Topical Report No. 1: Analysis of High Energy Arcing Fault (HEAF) Fire Events h published June 25, 2013 [1], illustrates that HEAF events have the potential to be major risk contributors with significant safety consequences and substantial economic loss. In an effort to better understand and characterize the threats posed by HEAF related phenomena, an international project has been chartered; the Joint Analysis of Arc Faults (Joan of ARC) OECD International Testing Program for High Energy Arc Faults. One of the major challenges of this research is how to properly measure and characterize the risk and influence of these events. Methods are being developed to characterize relevant parameters such as; temperature, heat flux, and heat release rate of fires resulting from HEAF events. Full scale experiments are being performed at low (≤ 1000 V) and medium (≤ 35 kV) voltages in electrical components. This paper introduces the methods being developed to measure thermal effects and discusses preliminary results of full scale HEAF experiments.

  2. Characterizing aging effects of lithium ion batteries by impedance spectroscopy

    International Nuclear Information System (INIS)

    Troeltzsch, Uwe; Kanoun, Olfa; Traenkler, Hans-Rolf

    2006-01-01

    Impedance spectroscopy is one of the most promising methods for characterizing aging effects of portable secondary batteries online because it provides information about different aging mechanisms. However, application of impedance spectroscopy 'in the field' has some higher requirements than for laboratory experiments. It requires a fast impedance measurement process, an accurate model applicable with several batteries and a robust method for model parameter estimation. In this paper, we present a method measuring impedance at different frequencies simultaneously. We propose to use a composite electrode model, capable to describe porous composite electrode materials. A hybrid method for parameter estimation based on a combination of evolution strategy and Levenberg-Marquardt method allowed a robust and fast parameter calculation. Based on this approach, an experimental investigation of aging effects of a lithium ion battery was carried out. After 230 discharge/charge cycles, the battery showed a 14% decreased capacity. Modeling results show that series resistance, charge transfer resistance and Warburg coefficient changed thereby their values by approximately 60%. A single frequency impedance measurement, usually carried out at 1 kHz, delivers only information about series resistance. Impedance spectroscopy allows additionally the estimation of charge transfer resistance and Warburg coefficient. This fact and the high sensitivity of model parameters to capacity change prove that impedance spectroscopy together with an accurate modeling deliver information that significantly improve characterization of aging effects

  3. Characterizing aging effects of lithium ion batteries by impedance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Troeltzsch, Uwe [University of the Bundeswehr Munich Institute for Measurement and Automation, 85579 Neubiberg (Germany)]. E-mail: uwe.troeltzsch@unibw-muenchen.de; Kanoun, Olfa [University of the Bundeswehr Munich Institute for Measurement and Automation, 85579 Neubiberg (Germany); Traenkler, Hans-Rolf [University of the Bundeswehr Munich Institute for Measurement and Automation, 85579 Neubiberg (Germany)

    2006-01-20

    Impedance spectroscopy is one of the most promising methods for characterizing aging effects of portable secondary batteries online because it provides information about different aging mechanisms. However, application of impedance spectroscopy 'in the field' has some higher requirements than for laboratory experiments. It requires a fast impedance measurement process, an accurate model applicable with several batteries and a robust method for model parameter estimation. In this paper, we present a method measuring impedance at different frequencies simultaneously. We propose to use a composite electrode model, capable to describe porous composite electrode materials. A hybrid method for parameter estimation based on a combination of evolution strategy and Levenberg-Marquardt method allowed a robust and fast parameter calculation. Based on this approach, an experimental investigation of aging effects of a lithium ion battery was carried out. After 230 discharge/charge cycles, the battery showed a 14% decreased capacity. Modeling results show that series resistance, charge transfer resistance and Warburg coefficient changed thereby their values by approximately 60%. A single frequency impedance measurement, usually carried out at 1 kHz, delivers only information about series resistance. Impedance spectroscopy allows additionally the estimation of charge transfer resistance and Warburg coefficient. This fact and the high sensitivity of model parameters to capacity change prove that impedance spectroscopy together with an accurate modeling deliver information that significantly improve characterization of aging effects.

  4. Characterization of Hall effect thruster propellant distributors with flame visualization

    Science.gov (United States)

    Langendorf, S.; Walker, M. L. R.

    2013-01-01

    A novel method for the characterization and qualification of Hall effect thruster propellant distributors is presented. A quantitative measurement of the azimuthal number density uniformity, a metric which impacts propellant utilization, is obtained from photographs of a premixed flame anchored on the exit plane of the propellant distributor. The technique is demonstrated for three propellant distributors using a propane-air mixture at reservoir pressure of 40 psi (gauge) (377 kPa) exhausting to atmosphere, with volumetric flow rates ranging from 15-145 cfh (7.2-68 l/min) with equivalence ratios from 1.2 to 2.1. The visualization is compared with in-vacuum pressure measurements 1 mm downstream of the distributor exit plane (chamber pressure held below 2.7 × 10-5 Torr-Xe at all flow rates). Both methods indicate a non-uniformity in line with the propellant inlet, supporting the validity of the technique of flow visualization with flame luminosity for propellant distributor characterization. The technique is applied to a propellant distributor with a manufacturing defect in a known location and is able to identify the defect and characterize its impact. The technique is also applied to a distributor with numerous small orifices at the exit plane and is able to resolve the resulting non-uniformity. Luminosity data are collected with a spatial resolution of 48.2-76.1 μm (pixel width). The azimuthal uniformity is characterized in the form of standard deviation of azimuthal luminosities, normalized by the mean azimuthal luminosity. The distributors investigated achieve standard deviations of 0.346 ± 0.0212, 0.108 ± 0.0178, and 0.708 ± 0.0230 mean-normalized luminosity units respectively, where a value of 0 corresponds to perfect uniformity and a value of 1 represents a standard deviation equivalent to the mean.

  5. Ecological concepts

    International Nuclear Information System (INIS)

    1986-01-01

    This volume contains three critical contributions on the application of modern technology from the ethical point of view. The peaceful use of nuclear power is rejected as a technical error, which is overwhelming humanity. Ethical bases of a preventive technological policy and ecological aims are developed for the 21st century, in economy, technology, politics, and consciousness. (HSCH) [de

  6. Information Ecology

    DEFF Research Database (Denmark)

    Christiansen, Ellen Tove

    2006-01-01

    in the 1960ties, and chosen here because it integrates cultural and psychological trajectories in a theory of living settings. The pedagogical-didactical paradigm comprises three distinct information ecologies, named after their intended outcome: the problem-setting, the exploration-setting, and the fit...

  7. Effects of shelter and enrichment on the ecology and nutrient cycling of microbial communities of subtidal carbonate sediments.

    Science.gov (United States)

    Forehead, Hugh I; Kendrick, Gary A; Thompson, Peter A

    2012-04-01

    The interactions between physical disturbances and biogeochemical cycling are fundamental to ecology. The benthic microbial community controls the major pathway of nutrient recycling in most shallow-water ecosystems. This community is strongly influenced by physical forcing and nutrient inputs. Our study tests the hypotheses that benthic microbial communities respond to shelter and enrichment with (1) increased biomass, (2) change in community composition and (3) increased uptake of inorganic nutrients from the water column. Replicate in situ plots were sheltered from physical disturbance and enriched with inorganic nutrients or left without additional nutrients. At t(0) and after 10 days, sediment-water fluxes of nutrients, O(2) and N(2) , were measured, the community was characterized with biomarkers. Autochthonous benthic microalgal (BMA) biomass increased 30% with shelter and a natural fivefold increase in nutrient concentration; biomass did not increase with greater enrichment. Diatoms remained the dominant taxon of BMA, suggesting that the sediments were not N or Si limited. Bacteria and other heterotrophic organisms increased with enrichment and shelter. Daily exchanges of inorganic nutrients between sediments and the water column did not change in response to shelter or nutrient enrichment. In these sediments, physical disturbance, perhaps in conjunction with nutrient enrichment, was the primary determinant of microbial biomass. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  8. Drift algae, an invasive snail and elevated temperature reduce ecological performance of a warm-temperate seagrass, through additive effects

    DEFF Research Database (Denmark)

    Hoffle, H.; Wernberg, T.; Thomsen, M. S.

    2012-01-01

    Seagrasses are under pressure from multiple concurrent threats, including rising temperatures, invasive species and nutrient-driven algal accumulations. We quantified the abundance of drift algae and the invasive snail Batillaria australis in 3 Halophila ovalis seagrass beds in the Swan River....... The survey showed that drift algae varied considerably between sites and sampling times, and sites experienced average loads of 0.4 to 0.8 kg fresh wt m(-2) and extreme loads up to 2.5 kg fresh wt m(-2). In contrast, invasive snails were constantly abundant at all sites at all collection times (mean...... reduced the length of the 2nd inter node. We found relatively few significant higher-order interactions, suggesting a dominance of additive effects of stress. We conclude that temperature, drift algae and invasive snails are already affecting the ecological performance of H. ovalis in Swan River...

  9. Effect of ecological management of weed control on economical income, yield and yield components of cotton (Gossypium hirsutum L.

    Directory of Open Access Journals (Sweden)

    A. Zare Feizabadi

    2016-04-01

    Full Text Available In order to compare of ecological management of weed control on economical income, yield and yield components of cotton (Gossypium hirsutum L., a Randomized Complete Block design with 12 treatments and four replications was conducted in Mahvelat of Khorasan Razavi province, Iran. Treatments consisted of weeding, harrowing, burning, two times weeding, weeding + harrowing, weeding + burning, harrowing + harrowing, harrowing + weeding, harrowing + burning, weeding+ harrowing+ burning, weed free and weedy as a check treatment. Investigated traits were plant height, number of boll in plant, 20 boll weight, 20 boll cotton lint weight, cotton lint yield per plant, cotton yield, number and biomass of weeds, outcome, net and gross income. The result showed that treatments had significant effect (p

  10. An ecological momentary assessment of the effect of fasting during Ramadan on disordered eating behaviors.

    Science.gov (United States)

    Chia, Jia Li Pauline; Fuller-Tyszkiewicz, Matthew; Buck, Kimberly; Chamari, Karim; Richardson, Ben; Krug, Isabel

    2018-04-23

    Dietary restriction contributes to disordered eating (DE) behaviors and associated cognitions. However, it is unclear how these outcomes are impacted by dietary restriction for religious purposes, such as fasting observed by Muslims during Ramadan. Using ecological momentary assessment, this study assessed the impact of Ramadan fasting on DE behaviors and correlates. Muslim participants fasting during Ramadan (n = 28) and a control group of non-fasting participants (n = 74) completed baseline measures assessing demographic characteristics and eating pathology. A mobile phone application then prompted participants six times per day for seven days to self-report on dietary restriction efforts, body satisfaction, temptation to eat unhealthily, feelings of guilt or shame following food, and DE behaviors including bingeing, vomiting, and other purging behaviors (use of laxatives, diuretics, or diet pills). After controlling for eating pathology, multilevel modeling indicated that, as expected, the Ramadan fasting group spent significantly more time restricting food intake than the non-fasting group. The Ramadan fasting group also experienced significantly greater temptation to eat unhealthily than their non-fasting counterparts. However, this difference disappeared once models were adjusted for differences in time spent restricting food intake. There were no other significant differences between the groups on any DE variables. These findings suggest that while dietary restriction for health or appearance-related reasons is a known contributor to DE, dietary restriction for religious purposes, such as that observed during the practice of Ramadan, may not confer increased risk of DE symptoms. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Future of car-sharing in Germany: Customer potential estimation, diffusion and ecological effect

    International Nuclear Information System (INIS)

    Wilke, Georg; Bongardt, Daniel

    2007-01-01

    The article summarises selected key results of the project 'Future of Car-Sharing in Germany', funded by the Federal Ministry of Education and Research. The target of the research was to improve the informational basis for the traffic and environmental assessment of car-sharing in Germany by means of an empirically based estimation of the medium-term perspective (time horizon 2020). Intermediate results were presented at the ECEEE congress 2005.Basis of the demand analyses, which were aligned to the milieu concept, was provided by two surveys (a non-representative survey of circa 500 customers and former customers and a representative survey of around 1,500 non-customers). In the interviews two service scenarios of a 'new' Car-Sharing in the shape of short-term car rental without ecological requirements were used. The analysis of the surveys was differentiated on two levels: On general level covering the whole sample and on the level of sub-samples covering the different milieus. Findings are provided with regard to prospective customers (social milieu affiliation, social profiles, notional using patterns) and backgrounds of their interest in short-term car rental as well as results of a customer potential estimation and a traffic and eco-balance. The results show that a diffusion of short-term car rentals appears feasible with an eco-balance remaining positive. For various reasons, the market development to be achieved by the year 2020, however, should be relatively limited. Similar is true for the potential contribution of car-sharing to a sustainable mobility altogether

  12. Recent advances in primate nutritional ecology.

    Science.gov (United States)

    Righini, Nicoletta

    2017-04-01

    Nutritional ecology seeks to explain, in an ecological and evolutionary context, how individuals choose, acquire, and process food to satisfy their nutritional requirements. Historically, studies of primate feeding ecology have focused on characterizing diets in terms of the botanical composition of the plants consumed. Further, dietary studies have demonstrated how patch and food choice in relation to time spent foraging and feeding are influenced by the spatial and temporal distribution of resources and by social factors such as feeding competition, dominance, or partner preferences. From a nutritional perspective, several theories including energy and protein-to-fiber maximization, nutrient mixing, and toxin avoidance, have been proposed to explain the food choices of non-human primates. However, more recently, analytical frameworks such as nutritional geometry have been incorporated into primatology to explore, using a multivariate approach, the synergistic effects of multiple nutrients, secondary metabolites, and energy requirements on primate food choice. Dietary strategies associated with nutrient balancing highlight the tradeoffs that primates face in bypassing or selecting particular feeding sites and food items. In this Special Issue, the authors bring together a set of studies focusing on the nutritional ecology of a diverse set of primate taxa characterized by marked differences in dietary emphasis. The authors present, compare, and discuss the diversity of strategies used by primates in diet selection, and how species differences in ecology, physiology, anatomy, and phylogeny can affect patterns of nutrient choice and nutrient balancing. The use of a nutritionally explicit analytical framework is fundamental to identify the nutritional requirements of different individuals of a given species, and through its application, direct conservation efforts can be applied to regenerate and protect specific foods and food patches that offer the opportunity of a

  13. A method for evaluating the effectiveness of site characterization measurements

    International Nuclear Information System (INIS)

    Ditmars, J.D.

    1987-01-01

    A quantitative approach for evaluating the effectiveness of site characterization measurement activities is developed and illustrated with an example application to hypothetical measurement schemes at a potential geologic repository site for radioactive waste. The method is a general one and could also be applied at sites for underground disposal of hazardous chemicals. The approach presumes that measurements will be undertaken to support predictions of the performance of some aspect of a constructed facility or natural system. It requires a quantitative performance objective, such as groundwater travel time or contaminant concentration, against which to compare predictions of performance. The approach recognizes that such predictions are uncertain because the measurements upon which they are based are uncertain. The effectiveness of measurement activities is quantified by a confidence index, β, that reflects the number of standard deviations separating the best estimate of performance from the predetermined performance objective. Measurements that reduce the uncertainty in predictions lead to increased values of β. 5 refs., 4 figs

  14. Ecological alarm system for Itaipu

    Energy Technology Data Exchange (ETDEWEB)

    Faehser, L.

    1984-05-01

    At Itaipu, on the Rio Parana, Brazil and Paraguay are constructing the world's largest hydro-electric power plant with a capacity seven times as high as that of Assuan. An information system is intended to give fair warning in case of threatening ecological conditions. The computer-supported alarm system had four objectives: 1. presentation of the present ecological situation; 2. evaluation of the ecological risks; 3. warning about ecological deficits; 4. suggestions for establishing ecological stability. In a first step the available inventory data concerning soil, topography, vegetation and water were evaluated by expert groups according to their risk grade (0-4) and ecological weight (1-10). The product of these evaluations indicates the ecological deficit (0-40). At a threshold value of 30, the information system automatically signals ecological alarm and locates the centre of danger via computer-plotted maps and tables. The necessary data are supplied periodically by selected measurement stations. Quantification of ecological facts enables the persons who are responsible for decisions at Itaipu to recognize, avoid, or diminish elements of danger even if they have little or no ecological knowledge. The file of data that has been compiled so far should be extended parallel with the development in the Itaipu area. With the help of factor analysis connections of cause and effect can be detected in this extremely complex reservoir system which has hardly been explored yet.

  15. Ecological impact assessment

    International Nuclear Information System (INIS)

    Thomas, J.M.; Eberhardt, L.L.

    1975-01-01

    Quantitative problems in accomplishing ecological impact assessment with particular reference to defining population effects are discussed with some comments on the two approaches most commonly used, e.g., the experimental and simulation models. Some alternatives are suggested because both methods will probably fail to detect real population effects mostly due to poor understanding of ecosystems or because of the limitations inherent in field census methods. Most judgments of ecological impact are not quantitatively defensible but are qualitative, subjective, or political in nature. An examination of aggregates of data from various nuclear power plant sites may be one way to obtain enough replication to judge ecological impact. Thus, currently available data from such studies as well as appropriate demographic, vegetation, census, and bibliographic material could offer an interesting challenge to computer professionals if such an undertaking were contemplated. Present research programs at PNL and computer involvement are described. Future possibilities and directions are discussed. (U.S.)

  16. Mercury: Aspects of its ecology and environmental toxicity. [physiological effects of mercury compound contamination of environment

    Science.gov (United States)

    Siegel, S. M.

    1973-01-01

    A study was conducted to determine the effects of mercury pollution on the environment. The possible sources of mercury contamination in sea water are identified. The effects of mercury on food sources, as represented by swordfish, are analyzed. The physiological effects of varying concentrations of mercury are reported. Emphasis is placed on the situation existing in the Hawaiian Islands.

  17. Asymmetric effects of native and exotic invasive shrubs on ecology of the West Nile virus vector Culex pipiens (Diptera: Culicidae).

    Science.gov (United States)

    Gardner, Allison M; Allan, Brian F; Frisbie, Lauren A; Muturi, Ephantus J

    2015-06-16

    Exotic invasive plants alter the structure and function of native ecosystems and may influence the distribution and abundance of arthropod disease vectors by modifying habitat quality. This study investigated how invasive plants alter the ecology of Culex pipiens, an important vector of West Nile virus (WNV) in northeastern and midwestern regions of the United States. Field and laboratory experiments were conducted to test the hypothesis that three native leaf species (Rubus allegheniensis, blackberry; Sambucus canadensis, elderberry; and Amelanchier laevis, serviceberry), and three exotic invasive leaf species (Lonicera maackii, Amur honeysuckle; Elaeagnus umbellata, autumn olive; and Rosa multiflora, multiflora rose) alter Cx. pipiens oviposition site selection, emergence rates, development time, and adult body size. The relative abundance of seven bacterial phyla in infusions of the six leaf species also was determined using quantitative real-time polymerase chain reaction to test the hypothesis that variation in emergence, development, and oviposition site selection is correlated to differences in the diversity and abundance of bacteria associated with different leaf species, important determinants of nutrient quality and availability for mosquito larvae. Leaf detritus from invasive honeysuckle and autumn olive yielded significantly higher adult emergence rates compared to detritus from the remaining leaf species and honeysuckle alleviated the negative effects of intraspecific competition on adult emergence. Conversely, leaves of native blackberry acted as an ecological trap, generating high oviposition but low emergence rates. Variation in bacterial flora associated with different leaf species may explain this asymmetrical production of mosquitoes: emergence rates and oviposition rates were positively correlated to bacterial abundance and diversity, respectively. We conclude that the displacement of native understory plant species by certain invasive shrubs

  18. Effectiveness of post-fire seeding at the Fitzner-Eberhardt Arid Land Ecology Reserve, Washington

    Science.gov (United States)

    Wirth, Troy A.; Pyke, David A.

    2011-01-01

    In August 2007, the Milepost 17 and Wautoma fires burned a combined total of 77,349 acres (31,302 hectares) of the Fitzner-Eberhardt Arid Land Ecology Reserve (ALE), part of the Hanford Reach National Monument administered by the U.S. Fish and Wildlife Service (USFWS) Mid-Columbia National Wildlife Refuge. In 2009, the USFWS implemented a series of seeding and herbicide treatments to mitigate potential negative consequences of these fires, including mortality of native vegetation, invasion of Bromus tectorum (cheatgrass), and soil erosion. Treatments included combinations of seeding (drill and aerial), herbicides, and one of six different mixtures of species. Artemisia tridentata ssp. wyomingensis (Wyoming big sagebrush) also was planted by hand in a small area in the southern end of the fire perimeter. Due to differences in plant communities prior to the fire and the multiple treatments applied, treatments were grouped into five treatment associations including mid-elevation aerial seedings, low-elevation aerial seedings, low-elevation drill seedings, high-elevation drill seeding, and no seeding treatments. Data collected at the mid-elevation aerial seedings indicate that the seeding did not appear to increase the density of seedlings compared to the non-seeded area in 2010. At the low-elevation aerial seedings, there were significantly more seedlings at seeded areas as compared to non-seeded areas. Low densities of existing perennial plants probably fostered a low-competition environment enabling seeds to germinate and emerge in 2010 during adequate moisture. Low-elevation drill seedings resulted in significant emergence of seeded grasses in 2009 and 2010 and forbs in 2010. This was likely due to adequate precipitation and that the drill seeding assured soil-to-seed contact. At the high-elevation drill seeding, which was implemented in 2009, there were a high number of seedlings in 2010. Transplanting of A. tridentata following the fires resulted in variable

  19. Will the Effects of Sea-Level Rise Create Ecological Traps for Pacific Island Seabirds?

    Directory of Open Access Journals (Sweden)

    Michelle H Reynolds

    Full Text Available More than 18 million seabirds nest on 58 Pacific islands protected within vast U.S. Marine National Monuments (1.9 million km2. However, most of these seabird colonies are on low-elevation islands and sea-level rise (SLR and accompanying high-water perturbations are predicted to escalate with climate change. To understand how SLR may impact protected islands and insular biodiversity, we modeled inundation and wave-driven flooding of a globally important seabird rookery in the subtropical Pacific. We acquired new high-resolution Digital Elevation Models (DEMs and used the Delft3D wave model and ArcGIS to model wave heights and inundation for a range of SLR scenarios (+0.5, +1.0, +1.5, and +2.0 m at Midway Atoll. Next, we classified vegetation to delineate habitat exposure to inundation and identified how breeding phenology, colony synchrony, and life history traits affect species-specific sensitivity. We identified 3 of 13 species as highly vulnerable to SLR in the Hawaiian Islands and quantified their atoll-wide distribution (Laysan albatross, Phoebastria immutabilis; black-footed albatross, P. nigripes; and Bonin petrel, Pterodroma hypoleuca. Our models of wave-driven flooding forecast nest losses up to 10% greater than passive inundation models at +1.0 m SLR. At projections of + 2.0 m SLR, approximately 60% of albatross and 44% of Bonin petrel nests were overwashed displacing more than 616,400 breeding albatrosses and petrels. Habitat loss due to passive SLR may decrease the carrying capacity of some islands to support seabird colonies, while sudden high-water events directly reduce survival and reproduction. This is the first study to simulate wave-driven flooding and the combined impacts of SLR, groundwater rise, and storm waves on seabird colonies. Our results highlight the need for early climate change planning and restoration of higher elevation seabird refugia to prevent low-lying protected islands from becoming ecological traps in the

  20. Ontogenetic patterns in bluefish (Pomatomus saltatrix) feeding ecology and the effect on mercury biomagnification.

    Science.gov (United States)

    Szczebak, Joseph T; Taylor, David L

    2011-06-01

    In this study, bluefish (Pomatomus saltatrix; age 0-7, n = 632) and their prey (forage fish, macroinvertebrates, zooplankton; n = 2,005) were collected from the Narragansett Bay estuary (RI, USA), and total Hg concentration was measured in white muscle and whole-body tissues, respectively. Bluefish Hg concentrations were analyzed relative to fish length, prey Hg content, and ontogenetic shifts in habitat use and foraging ecology, the latter assessed using stomach content analysis (n = 711) and stable nitrogen (δ(15)N) and carbon (δ(13)C) isotope measurements (n = 360). Diet and δ(13)C analysis showed that age 0 bluefish consumed both benthic and pelagic prey (silversides, sand shrimp, planktonic crustaceans; δ(13)C = - 16.52‰), whereas age 1 + bluefish fed almost exclusively on pelagic forage fish (Atlantic menhaden, herring; δ(13)C = - 17.33‰). Bluefish total Hg concentrations were significantly correlated with length (mean Hg = 0.041 and 0.254 ppm wet wt for age 0 and age 1 + bluefish, respectively). Furthermore, Hg biomagnification rates were maximal during bluefish early life stages and decelerated over time, resulting in relatively high Hg concentrations in age 0 fish. Rapid Hg accumulation in age 0 bluefish is attributed to these individuals occupying a comparable trophic level to age 1 + bluefish (δ(15)N = 15.58 and 16.09‰; trophic level = 3.55 and 3.71 for age 0 and age 1 + bluefish, respectively), as well as juveniles having greater standardized consumption rates of Hg-contaminated prey. Finally, bluefish larger than 30 cm total length consistently had Hg levels above the U.S. Environmental Protection Agency criterion of 0.3 ppm. As such, frequent consumption of bluefish could pose a human health risk, and preferentially consuming smaller bluefish may be an inadequate strategy for minimizing human dietary exposure to Hg. Copyright © 2011 SETAC.

  1. Political ecology

    International Nuclear Information System (INIS)

    Strohm, H.

    1979-01-01

    Using facts and examples, this didactically structures textbook gives an insight into the extent and consequences of the damage to the environment, with the subjects - fundamentals of ecology; - population and food problems; - the energy problem; - economic growth; scarcity of resources, recycling; - ground, water, and air pollution, - city and traffic problems; - work protection and medical care; - political alternatives and 'soft technologies'. The analysis of the political and economic reasons is combined with social and technical alternatives from which demands to be made and measures to be taken can be derived for individuals, citizens' interest groups, political groups and trade unions. Teaching models intend to help teachers to work on specific problems of ecology. (orig.) [de

  2. Wasteland ecologies

    DEFF Research Database (Denmark)

    Hoag, Colin Brewster; Bertoni, Filippo; Bubandt, Nils Ole

    2018-01-01

    landscapes, this article argues, are the result of unheralded multispecies collaboration that can be traced empirically by attending ethnographically to multispecies forms of “gain-making,” the ways in which humans and other species leverage difference to find economic and ecological opportunity....... in the 1970s, when prevailing perceptions were that the entire mining area was a polluted wasteland, the AFLD Fasterholt waste and recycling plant has since changed in response to new EU waste management regulations, as well as the unexpected proliferation of non-human life in the area. Based on field...... research at this site—an Anthropocene landscape in the heartland of an EU-configured welfare state — this article is a contribution to the multispecies ethnography and political ecology of wastelands. We argue that “waste” is a co-species, biopolitical happening — a complex symbolic, political, biological...

  3. Framework for ecological risk assessment

    International Nuclear Information System (INIS)

    Rodier, D.; Norton, S.

    1992-02-01

    Increased interest in ecological issues such as global climate change, habitat loss, acid deposition, reduced biological diversity, and the ecological impacts of pesticides and toxic chemicals prompts this U.S. Environmental Protection Agency (EPA) report, A Framework for Ecological Risk Assessment ('Framework Report'). The report describes basic elements, or a framework, for evaluating scientific information on the adverse effects of physical and chemical stressors on the environment. The framework offers starting principles and a simple structure as guidance for current ecological risk assessments and as a foundation for future EPA proposals for risk assessment guidelines

  4. Effects of economic crises on population health outcomes in Latin America, 1981–2010: an ecological study

    Science.gov (United States)

    Williams, Callum; Gilbert, Barnabas James; Zeltner, Thomas; Watkins, Johnathan; Atun, Rifat; Maruthappu, Mahiben

    2016-01-01

    Objectives The relative health effects of changes in unemployment, inflation and gross domestic product (GDP) per capita on population health have not been assessed. We aimed to determine the effect of changes in these economic measures on mortality metrics across Latin America. Design Ecological study. Setting Latin America (21 countries), 1981–2010. Outcome measures Uses multivariate regression analysis to assess the effects of changes in unemployment, inflation and GDP per capita on 5 mortality indicators across 21 countries in Latin America, 1981–2010. Country-specific differences in healthcare infrastructure, population structure and population size were controlled for. Results Between 1981 and 2010, a 1% rise in unemployment was associated with statistically significant deteriorations (pinflation rate was associated with significant deteriorations (pinflation, significant deteriorations (pinflation. Conclusions Rises in unemployment and inflation are associated with long-lasting deteriorations in several population health outcomes. Unemployment exerted much larger effects on health than inflation. In contrast, changes in GDP per capita had almost no association with the explored health outcomes. Contrary to neoclassical development economics, policymakers should prioritise amelioration of unemployment if population health outcomes are to be optimised. PMID:26739715

  5. Marine ecology

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    Studies on marine ecology included marine pollution; distribution patterns of Pu and Am in the marine waters, sediments, and organisms of Bikini Atoll and the influence of physical, chemical, and biological factors on their movements through marine biogeochemical systems; transfer and dispersion of organic pollutants from an oil refinery through coastal waters; transfer of particulate pollutants, including sediments dispersed during construction of offshore power plants; and raft culture of the mangrove oysters

  6. Effects of Microbial and Heavy Metal Contaminants on Environmental/Ecological Health and Revitalization of Coastal Ecosystems in Delaware Bay

    Directory of Open Access Journals (Sweden)

    Gulnihal Ozbay

    2017-06-01

    Full Text Available The presence of heavy metals, excess nutrients, and microbial contaminants in aquatic systems of coastal Delaware has become a public concern as human population increases and land development continues. Delaware's coastal lagoons have been subjected to problems commonly shared by other coastal Mid-Atlantic states: turbidity, sedimentation, eutrophication, periodic hypoxic/anoxic conditions, toxic substances, and high bacterial levels. The cumulative impact of pollutants from run-off and point sources has degraded water quality, reduced the diversity and abundance of various fish species, invertebrates, and submerged aquatic vegetation. The effects are especially pronounced within the manmade dead end canal systems. In this article, we present selected case studies conducted in the Delaware Inland Bays. Due to the ecological services provided by bivalves, our studies in Delaware Inland Bays are geared toward oysters with special focus on the microbial loads followed by the water quality assessments of the bay. The relationships between oysters (Crassostrea virginica, microbial loads and nutrient levels in the water were investigated. The heavy metal levels monitored further away from the waste water treatment plant in the inland bays are marginally higher than the recommended EPA limits. Also, our studies confirmed that aerobic bacteria and Vibrionaceae levels are salinity dependent. Total bacteria in oysters increased when nitrate and total suspended solids increased in the waters. Studies such as these are important because every year millions of Americans consume raw oysters. Data collected over the last 10 years from our studies may be used to build a predictive index of conditions that are favorable for the proliferation of human pathogenic bacteria. Results from this study will benefit the local community by helping them understand the importance of oyster aquaculture and safe consumption of oysters while making them appreciate their

  7. Terrestrial ecology

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    The main effort of the Terrestrial Ecology Division has been redirected to a comprehensive study of the Espiritu Santo Drainage Basin located in northeastern Puerto Rico. The general objective are to provide baseline ecological data for future environmental assessment studies at the local and regional levels, and to provide through an ecosystem approach data for the development of management alternatives for the wise utilization of energy, water, and land resources. The interrelationships among climate, vegetation, soils, and man, and their combined influence upon the hydrologic cycle will be described and evaluated. Environmental management involves planning and decision making, and both require an adequate data base. At present, little is known about the interworkings of a complete, integrated system such as a drainage basin. A literature survey of the main research areas confirmed that, although many individual ecologically oriented studies have been carried out in a tropical environment, few if any provide the data base required for environmental management. In view of rapidly changing socio-economic conditions and natural resources limitations, management urgently requires data from these systems: physical (climatological), biological, and cultural. This integrated drainage basin study has been designed to provide such data. The scope of this program covers the hydrologic cycle as it is affected by the interactions of the physical, biological, and cultural systems

  8. The ChimERA project: Coupling mechanistic exposure and effect models into an integrated platform for ecological risk assessment

    NARCIS (Netherlands)

    Laender, de F.; Brink, van den P.J.; Janssen, C.R.; Guardo, Di A.

    2014-01-01

    Current techniques for the ecological risk assessment of chemical substances are often criticised for their lack of environmental realism, ecological relevance and methodological accuracy. ChimERA is a 3-year project (2013-2016), funded by Cefic's Long Range Initiative (LRI) that aims to address

  9. Characterization of air freshener emission: the potential health effects.

    Science.gov (United States)

    Kim, Sanghwa; Hong, Seong-Ho; Bong, Choon-Keun; Cho, Myung-Haing

    2015-01-01

    Air freshener could be one of the multiple sources that release volatile organic compounds (VOCs) into the indoor environment. The use of these products may be associated with an increase in the measured level of terpene, such as xylene and other volatile air freshener components, including aldehydes, and esters. Air freshener is usually used indoors, and thus some compounds emitted from air freshener may have potentially harmful health impacts, including sensory irritation, respiratory symptoms, and dysfunction of the lungs. The constituents of air fresheners can react with ozone to produce secondary pollutants such as formaldehyde, secondary organic aerosol (SOA), oxidative product, and ultrafine particles. These pollutants then adversely affect human health, in many ways such as damage to the central nervous system, alteration of hormone levels, etc. In particular, the ultrafine particles may induce severe adverse effects on diverse organs, including the pulmonary and cardiovascular systems. Although the indoor use of air freshener is increasing, deleterious effects do not manifest for many years, making it difficult to identify air freshener-associated symptoms. In addition, risk assessment recognizes the association between air fresheners and adverse health effects, but the distinct causal relationship remains unclear. In this review, the emitted components of air freshener, including benzene, phthalate, and limonene, were described. Moreover, we focused on the health effects of these chemicals and secondary pollutants formed by the reaction with ozone. In conclusion, scientific guidelines on emission and exposure as well as risk characterization of air freshener need to be established.

  10. Electrohydrodynamic (EHD) Effects in Water Electrolytes and Theirs Applications to the Decision of Electromagnetic Ecology Problems

    International Nuclear Information System (INIS)

    Gak, E.Y.

    2001-01-01

    Experimental results of dispersion and coalescence water electrolytes drops and jets in electrical fields are given.Besides the peculiarities generation of some EHD-effects with the increase concentration electrolyte is examined. The role EHD-effects in living systems by influence nature and anthropogenic electromagnetic fields is discussed

  11. The Mozart Effect: Musical Phenomenon or Musical Preference? A More Ecologically Valid Reconsideration

    Science.gov (United States)

    Cassity, Hope Daniels; Henley, Tracy B.; Markley, Robert P.

    2007-01-01

    The "Mozart effect" is the reported phenomenon of increased spatial abilities after listening to that composer's music. However, subsequent research suggests that the Mozart effect may be an artifactual consequence of heightened arousal and mood rather than the music of Mozart per se (e.g., Thompson, Schellenberg, & Husain, 2001). The present…

  12. Effects of Human Development Index and Its Components on Colorectal Cancer Incidence and Mortality: a Global Ecological Study.

    Science.gov (United States)

    Khazaei, Salman; Rezaeian, Shahab; Khazaei, Somayeh; Mansori, Kamyar; Sanjari Moghaddam, Ali; Ayubi, Erfan

    2016-01-01

    Geographic disparity for colorectal cancer (CRC) incidence and mortality according to the human development index (HDI) might be expected. This study aimed at quantifying the effect measure of association HDI and its components on the CRC incidence and mortality. In this ecological study, CRC incidence and mortality was obtained from GLOBOCAN, the global cancer project for 172 countries. Data were extracted about HDI 2013 for 169 countries from the World Bank report. Linear regression was constructed to measure effects of HDI and its components on CRC incidence and mortality. A positive trend between increasing HDI of countries and age-standardized rates per 100,000 of CRC incidence and mortality was observed. Among HDI components education was the strongest effect measure of association on CRC incidence and mortality, regression coefficients (95% confidence intervals) being 2.8 (2.4, 3.2) and 0.9 (0.8, 1), respectively. HDI and its components were positively related with CRC incidence and mortality and can be considered as targets for prevention and treatment intervention or tracking geographic disparities.

  13. The biological effects of low doses of radiation: medical, biological and ecological aspects

    International Nuclear Information System (INIS)

    Gun-Aajav, T.; Ajnai, L.; Manlaijav, G.

    2007-01-01

    Full text: The results of recent studies show that low doses of radiation make many different structural and functional changes in a cell and these changes are preserved for a long time. This phenomenon is called as effects of low doses of radiation in biophysics, radiation biology and radiation medicine. The structural and functional changes depend on doses and this dependence has non-linear and bimodal behaviour. More detail, the radiation effect goes up and reaches its maximum (Low doses maximum) in low doses region, then it goes down and takes its stationary means (there is a negative effect in a few cases). With increases in doses and with further increases it goes up. It is established that low dose's maximum depends on physiological state of a biological object, radiation quality and dose rate. During the experiments another special date was established. This specialty is that many different physical and chemical factors are mutually connected and have synergetic behaviour. At present, researches are concentrating their attention on the following three directions: 1. Direct and indirect interaction of radiation's low doses: 2. Interpretation of its molecular mechanism, regulation of the positive effects and elaboration of ways o removing negative effects: 3. Application of the objective research results into practice. In conclusion the authors mention the current concepts on interpretation of low doses effect mechanism, forward their own views and emphasize the importance of considering low doses effects in researches of environmental radiation pollution, radiation medicine and radiation protection. (author)

  14. Ecological characterization of two species of exotic fish, pumpkinseed sunfish (Lepomis gibbosus) and largemouth bass (Micropterus salmoides) in the international Minho river

    OpenAIRE

    Ana Cristina Lages; Carlos Antunes

    2015-01-01

    The introduction of exotic species is considered the main cause for the decline of native species. The largemouth bass (Micropterus salmoides) and pumpkinseed sunfish (Lepomis gibbosus) are two native species from North America, introduced in Portugal to enhance sport fishing. However, their diet and great adaptability made them considered predatory and harmful. In order to understand the ecological impact of M. salmoides and L. gibbosus in the international section of the Minho River, three ...

  15. Aquatic predicted no-effect concentration for three polycyclic aromatic hydrocarbons and probabilistic ecological risk assessment in Liaodong Bay of the Bohai Sea, China.

    Science.gov (United States)

    Wang, Ying; Wang, Juying; Mu, Jingli; Wang, Zhen; Yao, Ziwei; Lin, Zhongsheng

    2014-01-01

    Predicted no-effect concentration (PNEC) is often used in ecological risk assessment to determine low-risk concentrations for chemicals. In the present study, native marine species were selected for toxicity testing. The PNECs for three polycyclic aromatic hydrocarbons (PAHs), specifically phenanthrene (Phe), pyrene (Pyr), and benzo[a]pyrene (BaP), were derived from chronic and acute toxicity data with log-normal statistical methods. The achieved PNECs for Phe, Pyr, and BaP were 2.33, 1.09, and 0.011 μg/L, respectively. In Jinzhou Bay and the Shuangtaizi River Estuary of Liaodong Bay in the Bohai Sea, China, the surface water concentrations of the three PAHs were analyzed by gas chromatography-mass spectrometry. Based on two probabilistic ecological risk assessment (PERA) methods, namely probabilistic risk quotient and joint probability curve, the potential risk of Phe, Pyr, and BaP in Jinzhou Bay and Shuangtaizi River Estuary was assessed. The same order of ecological risk (BaP > Phe > Pyr) was found by both models. Our study considered regional characteristics of marine biota during the calculation of PNECs, and the PERA methods provided probabilities of potential ecological risks of chemicals. Within the study area, further research on BaP is required due to its high potential ecological risk.

  16. Effects of island seabird subsidies and invasive species dynamics on the body size and foraging ecology of the Allen Cays Rock Iguana (Cyclura cychlura inornata)

    OpenAIRE

    Richardson, Kristen Mundie

    2015-01-01

    Island systems have long been valuable to ecological research as they provide natural experiments for the study of ecosystem processes. We examined Allen, Leaf, U and Flat Rock Reef Cays in the Bahamas to study the effects of seabird driven marine subsidies and invasive mice on island food webs on the body size and foraging ecology of the Allen Cays Rock Iguana (Cyclura cychlura inornata). Iguanas on an island with nesting seabirds (Allen Cay) had 6 times the body mass and 1.7 times the snout...

  17. About possibility of creation of ecologically pure, safe nuclear power plants on the basis of high-effective resonant neutron interaction with splitting substances

    International Nuclear Information System (INIS)

    Irdyncheyev, L.A.; Malofeyev, A.M.; Frid, E.S.; Abramov, E.P.

    1993-01-01

    Currently the most important problem in nuclear engineering is creation of ecologically pure, safe nuclear power plants in the context of real danger of global ecological pollution of the environment with long-lived fission products and the resultant transuranium nuclides. The problem can be solved by creating nuclear power plants on the basis of high-effective resonant interaction (HERI). Such power plants would provide the total cycle, including nuclear fuel production (Plutonium-239 from Uranium-238), combustion and waste products salvaging by way of transformation of radioactive nuclides into stable isotopes

  18. Effects of stream topology on ecological community results from neutral models

    Science.gov (United States)

    While neutral theory and models have stimulated considerable literature, less well investigated is the effect of topology on neutral metacommunity model simulations. We implemented a neutral metacommunity model using two different stream network topologies, a widely branched netw...

  19. Ecological effects of low toxicity oil-based mud drilling in the Beatrice oilfield

    Energy Technology Data Exchange (ETDEWEB)

    Addy, J M; Hartley, J P; Tibbetts, P J.C.

    1984-12-01

    To investigate the effects of drilling discharges on the seabed fauna, surveys were carried out in the Beatrice oilfield after drilling 13 wells with water-based muds, and then after one and five further wells had been drilled using low toxicity oil-based muds. Localized benthic effects were found after the water-based mud drilling. After the use of oil-based muds, the nature of the effects was different, although there was little increase in the area involved. Possible reasons for this are discussed and burial and organic enrichment are suggested as the major influences. It is concluded that the use of low toxicity oil-based mud at Beatrice has resulted in only limited benthic effects, suggesting that the use of these muds is environmentally acceptable.

  20. Ecological effects of nuclear steam electric station operations on estuarine systems. Final report

    International Nuclear Information System (INIS)

    Mihursky, J.A.

    1983-01-01

    This report summarizes the findings of studies of the impact of the Calvert Cliffs Nuclear Power Plant on the aquatic biota of Chesapeake Bay. Physical findings show that the typical radial extent of influence of the discharge on the physical and chemical environment of the Bay is rather limited (< 2 km). This suggestion is bolstered by findings of phytoplankton and zooplankton studies: when effects were noted at all, they only appeared at sampling stations nearest (within 2 km of) the discharge. Also, direct entrainment effects on these groups were either small (in the case of phytoplankton) or species-specific (in the case of zooplankton). Benthos showed mixed responses to plant operations - the populations of some species were enhanced, one species was adversely affected, and others were unaffected. The major plant effect on the benthos was due to habitat resource enrichment, and the consequence was higher standing stocks (e.g., more food for fish) in the affected area. Direct plant effects on finfish are dominated by impingement. Mortality as a result of impingement, for many species, tends to be moderate to slight. Effects as a result of entrainment of eggs and larvae are limited because the Calvert Cliffs area is not a major spawning location for any species. In sum, the Calvert Cliffs plant appears to have a limited effect on the Chesapeake Bay ecosystem. 180 references, 6 figures, 18 tables

  1. The effects of exposure to environmental factors on Heart Rate Variability: An ecological perspective

    International Nuclear Information System (INIS)

    Schnell, Izhak; Potchter, Oded; Epstein, Yoram; Yaakov, Yaron; Hermesh, Hagai; Brenner, Shmuel; Tirosh, Emanuel

    2013-01-01

    The impact of human exposure to environmental factors on Heart Rate Variability (HRV) was examined in the urban space of Tel-Aviv-Jaffa. Four environmental factors were investigated: thermal and social loads; CO concentrations and noise. Levels of HRV are explained mainly by subjective social stresses, noise and CO. The most interesting result is the fact that while subjective social stress and noise increase HRV, low levels of CO are reducing HRV to some extent moderating the impact of subjective social stress and noise. Beyond the poisoning effect of CO and the fact that extremely low levels of HRV associated with high dozes of CO increase risk for life, low levels of CO may have a narcotic effect, as it is measured by HRV. The effects of thermal loads on HRV are negligible probably due to the use of behavioral means in order to neutralize heat and cold effects. -- Highlights: ► The impact of human exposure to environmental factors on Heart Rate Variability (HRV) was examined. ► Previous studies measured human exposure to pollution by fixed monitoring stations. ► This study measured actual personal exposure by mini sensors. ► High level of subjective social load and noise increase HRV. ► Low levels of CO may have a narcotic effect, as it is measured by HRV. -- The research focuses on the effects of environmental factors; noise, subjective social stress, thermal load and CO on Heart Rate Variability

  2. Effects of addition of tilapia Oreochromis niloticus and substrates for periphyton developments on pond ecology and production in C/N-controlled freshwater prawn Macrobrachium rosenbergii farming systems

    NARCIS (Netherlands)

    Asaduzzaman, M.; Wahab, M.A.; Verdegem, M.C.J.; Benerjee, S.; Akter, T.; Hasan, M.M.; Azim, M.E.

    2009-01-01

    The present research investigated the effect of addition of tilapia and substrates for periphyton development on pond ecology, production and economic performances in C/N controlled freshwater prawn farming system. The absence and presence (0 and 0.5 individual m- 2) of tilapia were investigated in

  3. A hybrid land-water-environment model for identification of ecological effect and risk under uncertain meteorological precipitation in an agroforestry ecosystem.

    Science.gov (United States)

    Zeng, Xueting; Li, Tienan; Chen, Cong; Si, Zhenjiang; Huang, Guohe; Guo, Ping; Zhuang, Xiaowen

    2018-08-15

    In this study, a hybrid land-water-environment (LWE) model is developed for identifying ecological effect and risk under uncertain precipitation in an agroforestry ecosystem. A simulation-based fuzzy-stochastic programming with risk analysis (SFSR) method is used into LWE model to reflect the meteorological impacts; meanwhile, it also can quantify artificial fuzziness (e.g., risk attitude of policymaker) and natural vagueness (e.g., ecological function) in decision-making. The developed LWE model with SFSR method is applied to a practical agroforestry ecosystem in China. Results of optimized planting scale, irrigative water schedule, pollution mitigation scheme, and system benefit under changed rainfall, precise risk-adoption and vague ecological function are obtained; meanwhile their corresponding ecological effects and risks are analyzed. It found that current LWE plans could generate massive water deficits (e.g., 23.22×10 6 m 3 in crop irrigation and 26.32×10 6 m 3 in forest protection at highest) due to over-cultivation and excessive pollution discharges (e.g., the highest excessive TP and TN discharges would reach 460.64 and 15.30×10 3 ton) due to irrational fertilization, which would increase regional ecological risks. In addition, fifteen scenarios associated with withdrawing cultivation and recovering forest based on regional environment heterogeneity (such as soil types) have been discussed to adjust current agriculture-environment policies. It found that, the excessive pollution discharges (TN and TP) could be reduced 12.95% and 18.32% at highest through ecological expansions, which would generate higher system benefits than that without withdrawing farmland and recovering forest. All above can facilitate local policymakers to modulate a comprehensive LWE with more sustainable and robust manners, achieving regional harmony between socio-economy and eco-environment. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. How Hives Collapse: Allee Effects, Ecological Resilience, and the Honey Bee.

    Directory of Open Access Journals (Sweden)

    Brian Dennis

    Full Text Available We construct a mathematical model to quantify the loss of resilience in collapsing honey bee colonies due to the presence of a strong Allee effect. In the model, recruitment and mortality of adult bees have substantial social components, with recruitment enhanced and mortality reduced by additional adult bee numbers. The result is an Allee effect, a net per-individual rate of hive increase that increases as a function of adult bee numbers. The Allee effect creates a critical minimum size in adult bee numbers, below which mortality is greater than recruitment, with ensuing loss of viability of the hive. Under ordinary and favorable environmental circumstances, the critical size is low, and hives remain large, sending off viably-sized swarms (naturally or through beekeeping management when hive numbers approach an upper stable equilibrium size (carrying capacity. However, both the lower critical size and the upper stable size depend on many parameters related to demographic rates and their enhancement by bee sociality. Any environmental factors that increase mortality, decrease recruitment, or interfere with the social moderation of these rates has the effect of exacerbating the Allee effect by increasing the lower critical size and substantially decreasing the upper stable size. As well, the basin of attraction to the upper stable size, defined by the model potential function, becomes narrower and shallower, indicating the loss of resilience as the hive becomes subjected to increased risk of falling below the critical size. Environmental effects of greater severity can cause the two equilibria to merge and the basin of attraction to the upper stable size to disappear, resulting in collapse of the hive from any initial size. The model suggests that multiple proximate causes, among them pesticides, mites, pathogens, and climate change, working singly or in combinations, could trigger hive collapse.

  5. Effect of organic amendments and compost extracts on tomato production and storability in ecological production systems

    Directory of Open Access Journals (Sweden)

    ghorbani reza

    2009-06-01

    Full Text Available A field experiment was conducted in Shiravan, Iran, during 2005 in order to investigate the effects of organic amendments, synthetic fertilizers and compost extracts on crop health, productivity and storability of commonly used tomato (Lycopersicon esculentum Mill.. Treatments included different fertilizers of cattle, sheep and poultry manures, house-hold compost and chemical fertilizers, and five aqueous extracts from cattle manure, poultry manures, green-waste and house-hold composts and water as control. The effect of fertilizer type on tomato yield and marketable yield was significant (P

  6. Spatial effects of aboveground biomass on soil ecological parameters and trace gas fluxes in a savannah ecosystem of Mount Kilimanjaro

    Science.gov (United States)

    Becker, Joscha; Gütlein, Adrian; Sierra Cornejo, Natalia; Kiese, Ralf; Hertel, Dietrich; Kuzyakov, Yakov

    2015-04-01

    The savannah biome is a hotspot for biodiversity and wildlife conservation in Africa and recently got in the focus of research on carbon sequestration. Savannah ecosystems are under strong pressure from climate and land-use change, especially around populous areas like the Mt. Kilimanjaro region. Savannah vegetation in this area consists of grassland with isolated trees and is therefore characterized by high spatial variation of canopy cover, aboveground biomass and root structure. Canopy structure is known to affect microclimate, throughfall and evapotranspiration and thereby controls soil moisture conditions. Consequently, the canopy structure is a major regulator for soil ecological parameters and soil-atmospheric trace gas exchange (CO2, N2O, CH4) in water limited environments. The spatial distribution of these parameters and the connection between above and belowground processes are important to understand and predict ecosystem changes and estimate its vulnerability. Our objective was to determine trends and changes of soil parameters and relate their spatial variability to the vegetation structure. We chose three trees from each of the two most dominant species (Acacia nilotica and Balanites aegyptiaca) in our research area. For each tree, we selected transects with nine sampling points of the same relative distances to the stem. Distances were calculated in relation to the crown radius. At these each sampling point a soil core was taken and separated in 0-10 cm and 10-30 cm depth. We measured soil carbon (C) and nitrogen (N) storage, microbial biomass carbon C and N, soil respiration as well as root biomass and -density, soil temperature and soil water content. Each tree was characterized by crown spread, leaf area index and basal area. Preliminary results show that C and N stocks decreased about 50% with depth independently of distance to the tree. Soil water content under the tree crown increased with depth while it decreased under grass cover. Microbial

  7. Industrial ecology.

    Science.gov (United States)

    Patel, C K

    1992-01-01

    Industrial ecology addresses issues that will impact future production, use, and disposal technologies; proper use of the concept should reduce significantly the resources devoted to potential remediation in the future. This cradle-to-reincarnation production philosophy includes industrial processes that are environmentally sound and products that are environmentally safe during use and economically recyclable after use without adverse impact on the environment or on the net cost to society. This will require an industry-university-government round table to set the strategy and agenda for progress. PMID:11607254

  8. Hydro-power production and fish habitat suitability: Assessing impact and effectiveness of ecological flows at regional scale

    Science.gov (United States)

    Ceola, Serena; Pugliese, Alessio; Ventura, Matteo; Galeati, Giorgio; Montanari, Alberto; Castellarin, Attilio

    2018-06-01

    Anthropogenic activities along streams and rivers may be of major concern for fluvial ecosystems, e.g. abstraction and impoundment of surface water resources may profoundly alter natural streamflow regimes. An established approach aimed at preserving the behavior and distribution of fluvial species relies on the definition of ecological flows (e-flows) downstream of dams and diversion structures. E-flow prescriptions are usually set by basin authorities at regional scale, often without a proper assessment of their impact and effectiveness. On the contrary, we argue that e-flows should be identified on the basis of (i) regional and (ii) quantitative assessments. We focus on central Italy and evaluate the effects on habitat suitability of two near-threatened fish species (i.e. Barbel and Chub) and an existing hydro-power network when shifting from the current time-invariant e-flow policy to a tighter and seasonally-varying soon-to-be-enforced one. Our example clearly shows that: (a) quantitative regional scale assessments are viable even when streamflow observations are entirely missing at study sites; (b) aprioristic e-flows policies may impose releases that exceed natural streamflows for significantly long time intervals (weeks, or months); (c) unduly tightening e-flow policies may heavily impact regional hydro-power productivity (15% and 42% losses on annual and seasonal basis, respectively), yet resulting in either marginal or negligible improvements of fluvial ecosystem.

  9. Virginia flow-ecology modeling results—An initial assessment of flow reduction effects on aquatic biota

    Science.gov (United States)

    Rapp, Jennifer L.; Reilly, Pamela A.

    2017-11-14

    BackgroundThe U.S. Geological Survey (USGS), in cooperation with the Virginia Department of Environmental Quality (DEQ), reviewed a previously compiled set of linear regression models to assess their utility in defining the response of the aquatic biological community to streamflow depletion.As part of the 2012 Virginia Healthy Watersheds Initiative (HWI) study conducted by Tetra Tech, Inc., for the U.S. Environmental Protection Agency (EPA) and Virginia DEQ, a database with computed values of 72 hydrologic metrics, or indicators of hydrologic alteration (IHA), 37 fish metrics, and 64 benthic invertebrate metrics was compiled and quality assured. Hydrologic alteration was represented by simulation of streamflow record for a pre-water-withdrawal condition (baseline) without dams or developed land, compared to the simulated recent-flow condition (2008 withdrawal simulation) including dams and altered landscape to calculate a percent alteration of flow. Biological samples representing the existing populations represent a range of alteration in the biological community today.For this study, all 72 IHA metrics, which included more than 7,272 linear regression models, were considered. This extensive dataset provided the opportunity for hypothesis testing and prioritization of flow-ecology relations that have the potential to explain the effect(s) of hydrologic alteration on biological metrics in Virginia streams.

  10. Investigations on the Effects of Dietary Essential Oils and Different Husbandry Conditions on the Gut Ecology in Piglets after Weaning

    Directory of Open Access Journals (Sweden)

    P. Janczyk

    2009-01-01

    Full Text Available Essential oils (EO are being considered as possible alternatives to in-feed antibiotic growth promoters in pig nutrition. The effects of an EO mixture consisting of limonene, eugenol and pinene (10.0, 2.0, and 4.8 mg/kg diet, resp. on gut physiology and ecology were studied in piglets. The experiment was conducted at low (commercial farm and high hygienic conditions (experimental farm, to elucidate interactions between EO supplementation and husbandry methods. Piglets were weaned at 28 days of age, when they were offered either a control diet (C or C with EO. Four piglets were sacrificed in each group on day 29, 30, 33 and 39. Digesta from the third distal part of the small intestine and from the colon were sampled and analysed for pH, dry matter, lactic acid, short chain fatty acids and ammonia concentrations. Enterobacteria, enterococci, lactobacilli and yeast counts were obtained by plating. Genomic DNA was extracted from digesta and polymerase chain reaction—denaturing gradient gel electrophoresis was performed. Individual microbial communities were identified at each farm. Age affected the intestinal parameters. No effects of the EO with exception for a significant reduction in colon bacterial diversity at 39 days of age could be recorded at experimental farm.

  11. Ecological effects of prescribed fire season: a literature review and synthesis for managers

    Science.gov (United States)

    Eric E. Knapp; Becky L. Estes; Carl N. Skinner

    2009-01-01

    Prescribed burning may be conducted at times of the year when fires were infrequent historically, leading to concerns about potential adverse effects on vegetation and wildlife. Historical and prescribed fire regimes for different regions in the continental United States were compared and literature on season of prescribed burning synthesized. In regions and vegetation...

  12. Effects of grazing intensity on small mammal population ecology in wet meadows

    DEFF Research Database (Denmark)

    Schmidt, Niels Martin; Olsen, Henrik; Bildsøe, Mogens

    2005-01-01

    Livestock grazing is common management practice in wet grasslands. However, knowledge of its effects on small mammals is limited. We studied the influence of grazing intensity on small mammals in general and field voles Microtus agrestis in particular in two Danish wet meadows, 1998-2000. General...

  13. Emergency post-fire rehabilitation treatment effects on burned area ecology and long-term restoration

    Science.gov (United States)

    Peter R. Robichaud; Sarah A. Lewis; Robert E. Brown; Louise E. Ashmun

    2009-01-01

    The predicted continuation of strong drying and warming trends in the southwestern United States underlies the associated prediction of increased frequency, area, and severity of wildfires in the coming years. As a result, the management of wildfires and fire effects on public lands will continue to be a major land management priority for the foreseeable future....

  14. Ecological and statistical evaluation of effects of pesticides in freshwater model ecosystems

    NARCIS (Netherlands)

    Brink, van den P.J.

    1999-01-01

    Aquatic risk assessment of pesticides

    The first tier in the aquatic risk assessment procedure consists of a comparison between a Predicted Environmental Concentration (PEC) with a No Effect Concentration (NEC). A requirement for registration is that

  15. Ecological effects of Spring and late Summer applications of Lambda-Cyhalothrin on freshwater microcosms

    NARCIS (Netherlands)

    Wijngaarden, van R.P.A.; Brock, T.C.M.; Brink, van den P.J.; Gylstra, R.; Maund, S.J.

    2006-01-01

    The aim of the study was to compare the effects of the pyrethroid insecticide lambda-cyhalothrin (treated at 10, 25, 50, 100, 250 ng active ingredient a.i./L) on a drainage ditch ecosystem in spring and late summer. Microcosms (water volume approximately 430 L) were established using enclosures in a

  16. Effects of imidacloprid on the ecology of sub-tropical freshwater microcosms

    NARCIS (Netherlands)

    Sumon, Kizar Ahmed; Ritika, Afifat Khanam; Peeters, Edwin T.H.M.; Rashid, Harunur; Bosma, Roel H.; Rahman, Md Shahidur; Fatema, Mst Kaniz; Brink, Van den Paul J.

    2018-01-01

    The neonicotinoid insecticide imidacloprid is used in Bangladesh for a variety of crop protection purposes. Imidacloprid may contaminate aquatic ecosystems via spray drift, surface runoff and ground water leaching. The present study aimed at assessing the fate and effects of imidacloprid on

  17. The effect of invasive hybrid taxa on the ecological succession of coastal marshes

    Science.gov (United States)

    Hybridization following colonization of invasive species in novel environments frequently results in offspring with improved biological and competitive functions referred to as heterosis or hybrid vigor. However, little is known about the effect of these invasive hybrids on the structuring and funct...

  18. Ecological effects of spring and late summer applications of lambda-cyhalothrin on freshwater microcosms.

    Science.gov (United States)

    Van Wijngaarden, R P A; Brock, T C M; van den Brink, P J; Gylstra, R; Maund, S J

    2006-02-01

    The aim of the study was to compare the effects of the pyrethroid insecticide lambda-cyhalothrin (treated at 10, 25, 50, 100, 250 ng active ingredient a.i./L) on a drainage ditch ecosystem in spring and late summer. Microcosms (water volume approximately 430 L) were established using enclosures in a 50-cm-deep experimental ditch system containing communities typical of macrophyte-dominated freshwater ecosystems. Effects on macroinvertebrates, zooplankton, phytoplankton, macrophytes, and community metabolism were assessed and evaluated using univariate and multivariate statistical techniques. The macroinvertebrate community responded most clearly to treatment and, as anticipated, insects and crustaceans were among the most sensitive organisms. Statistical analysis showed that the underlying community structure was significantly different between the spring and summer experiments. However, the most sensitive species (Chaoborus obscuripes and Gammarus pulex) were abundant in spring as well as in late summer. In spring and late summer, only slight and transient effects were observed at the community level in the 10-ng/L treatment. Overall, the study did not show substantial differences in the responses of sensitive taxa between spring and late summer treatments, and effects thresholds were similar irrespective of season of treatment.

  19. Trace metals in floodplain lake sediments : SEM/AVS as indicator of bioavailability and ecological effects

    NARCIS (Netherlands)

    Griethuysen, van C.

    2006-01-01

    This thesis addresses the geochemical aspects of AVS (Acid Volatile Sulfide) and SEM (Simultaneously Extracted Metals) in floodplain lake sediment, its spatial distribution in floodplain lakes and dynamics over time, the link with effects on single species (bioassays), as well as the impact of

  20. Effectiveness of innovation leadership styles: a manager's influence on ecological innovation in construction projects

    OpenAIRE

    Bossink, B.A.G.

    2004-01-01

    This article presents four basic innovation leadership styles: charismatic, instrumental, strategic and interactive innovation leadership. The leadership styles and their characteristics relate to process and product innovations in construction projects. A theoretical framework - which synthesizes these relations enables explorative research into the effects of leadership on organizational innovativeness. Four case studies, observing the same manager in four comparable projects, explore the e...

  1. Ecological and evolutionary consequences of tri-trophic interactions: Spatial variation and effects of plant density.

    Science.gov (United States)

    Abdala-Roberts, Luis; Parra-Tabla, Víctor; Moreira, Xoaquín; Ramos-Zapata, José

    2017-02-01

    The factors driving variation in species interactions are often unknown, and few studies have made a link between changes in interactions and the strength of selection. We report on spatial variation in functional responses by a seed predator (SP) and its parasitic wasps associated with the herb Ruellia nudiflora . We assessed the influence of plant density on consumer responses and determined whether density effects and spatial variation in functional responses altered natural selection by these consumers on the plant. We established common gardens at two sites in Yucatan, Mexico, and planted R. nudiflora at two densities in each garden. We recorded fruit output and SP and parasitoid attack; calculated relative fitness (seed number) under scenarios of three trophic levels (accounting for SP and parasitoid effects), two trophic levels (accounting for SP but not parasitoid effects), and one trophic level (no consumer effects); and compared selection strength on fruit number under these scenarios across sites and densities. There was spatial variation in SP recruitment, whereby the SP functional response was negatively density-dependent at one site but density-independent at the other; parasitoid responses were density-independent and invariant across sites. Site variation in SP attack led, in turn, to differences in SP selection on fruit output, and parasitoids did not alter SP selection. There were no significant effects of density at either site. Our results provide a link between consumer functional responses and consumer selection on plants, which deepens our understanding of geographic variation in the evolutionary outcomes of multitrophic interactions. © 2017 Botanical Society of America.

  2. Characterization of behavioral and endocrine effects of LSD on zebrafish.

    Science.gov (United States)

    Grossman, Leah; Utterback, Eli; Stewart, Adam; Gaikwad, Siddharth; Chung, Kyung Min; Suciu, Christopher; Wong, Keith; Elegante, Marco; Elkhayat, Salem; Tan, Julia; Gilder, Thomas; Wu, Nadine; Dileo, John; Cachat, Jonathan; Kalueff, Allan V

    2010-12-25

    Lysergic acid diethylamide (LSD) is a potent hallucinogenic drug that strongly affects animal and human behavior. Although adult zebrafish (Danio rerio) are emerging as a promising neurobehavioral model, the effects of LSD on zebrafish have not been investigated previously. Several behavioral paradigms (the novel tank, observation cylinder, light-dark box, open field, T-maze, social preference and shoaling tests), as well as modern video-tracking tools and whole-body cortisol assay were used to characterize the effects of acute LSD in zebrafish. While lower doses (5-100 microg/L) did not affect zebrafish behavior, 250 microg/L LSD increased top dwelling and reduced freezing in the novel tank and observation cylinder tests, also affecting spatiotemporal patterns of activity (as assessed by 3D reconstruction of zebrafish traces and ethograms). LSD evoked mild thigmotaxis in the open field test, increased light behavior in the light-dark test, reduced the number of arm entries and freezing in the T-maze and social preference test, without affecting social preference. In contrast, LSD affected zebrafish shoaling (increasing the inter-fish distance in a group), and elevated whole-body cortisol levels. Overall, our findings show sensitivity of zebrafish to LSD action, and support the use of zebrafish models to study hallucinogenic drugs of abuse. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  3. Effect of microwave irradiation on petrophysical characterization of coals

    International Nuclear Information System (INIS)

    Hong, Yi-du; Lin, Bai-quan; Zhu, Chuan-jie; Li, He

    2016-01-01

    Highlights: • Microwave energy increase porosity, pore size and numbers of coals. • Growth rates of porosity decreased at first then increased with microwave energy. • NMR can be reliable to measure coal samples. • Microwave energy may have the potential for degassing of coal seams. - Abstract: The experimental work described in this paper aims to study the effect of microwave irradiation on petrophysical characterization of coals. Twenty coal samples were irradiated at 2.45 GHz with variable power (2, 4, 6 kW). The temperature, mass and specific heat capacity of coal samples were measured and calculated. The effect of microwave irradiation on the porosity of coal samples was evaluated by the gravimetric method and nuclear magnetic resonance (NMR) measurements. The porosity obviously increases after microwave heating. Interestingly, growth rate of the porosity decreases at first then increases with microwave energy. The turning point is approximately 100 kJ. The influence of microwave irradiation on pore size, throat size and pore numbers of coal samples were also evaluated by NMR measurements. It suggest that the pore size, throat size and pore numbers are obviously increase with microwave energy. In a word, it appears likely that microwave energy may have the potential for the degassing coal seams.

  4. Effects on parathion on the ecology of a eutrophic aquatic ecosystem: limnocorral experiment

    International Nuclear Information System (INIS)

    Gasith, A.; Perry, A.S.; Mozel, Y.; Albright, J.L.

    1983-01-01

    Repetitive exposure of a eutrophic fish pond ecosystem, enclosed in limnocorrals, to 30 ppb parathion resulted in elimination of the potentially dominant zooplankton species, Moina micrura. Consequently, the populations of the rotifers Brachionus and Asplanchna markedly increased. Changes in the zooplankton composition and abundance were followed by increased fluctuations in phytoplankton biomass, phytoplankton photosynthesis, plankton respiration and community metabolism. Similar responses to parathion treatment were observed in previous studies under fish pond conditions. In the presence of fish the effect of parathion on the ecosystem was generally less pronounced and not uniform. The collapse of the zooplankton community and the rapid changes in limnological conditions in the control (untreated) limnocorrals severely limited the duration of the experiment. The results suggest that under eutrophic conditions, small enclosures may be useful for evaluation of the effect of toxicants on the ecosystem only in short term experiments with short lived chemicals. (author)

  5. Physiological ecology of SRS Carolina bay phytoplankton communities: Effects of nutrient changes and CO2 sources

    International Nuclear Information System (INIS)

    Williams, J.B.

    1992-11-01

    Impacts of land-use activities on wetland ecosystems are important issues for environmental planners, conservation groups, and government agencies. The progress report of this project at DOE's Savannah River Site focused on two specific objectives: determination of the effects of nutrient enrichment (fertilizing during wetlands restoration) on phytoplankton communities and comparison of phytoplankton community dynamics during the current extended hydroperiod for Carolina Bays with patterns in previous drier years

  6. Knowledge acquisition in ecological poduct design: the effects of computer-mediated communication and elicitation method

    OpenAIRE

    Sauer, J.; Schramme, S.; Rüttinger, B.

    2000-01-01

    This article presents a study that examines multiple effects of using different means of computer-mediated communication and knowledge elicitation methods during a product design process. The experimental task involved a typical scenario in product design, in which a knowledge engineer consults two experts to generate knowledge about a design issue. Employing a 3x2 between-subjects design, three conference types (face-to-face, computer, multivedia) and two knowledge elicitation methods (struc...

  7. Ecological and statistical evaluation of effects of pesticides in freshwater model ecosystems

    OpenAIRE

    Brink, van den, P.J.

    1999-01-01

    Aquatic risk assessment of pesticides

    The first tier in the aquatic risk assessment procedure consists of a comparison between a Predicted Environmental Concentration (PEC) with a No Effect Concentration (NEC). A requirement for registration is that the PEC should not exceed the NEC. The NEC is calculated from the toxicity of the pesticide for defined standard test species (viz. algae Daphnia , fish) and an assessment factor...

  8. Effect of Lineage-Specific Metabolic Traits of Lactobacillus reuteri on Sourdough Microbial Ecology

    OpenAIRE

    Lin, Xiaoxi B.; Gänzle, Michael G.

    2014-01-01

    This study determined the effects of specific metabolic traits of Lactobacillus reuteri on its competitiveness in sourdoughs. The competitiveness of lactobacilli in sourdough generally depends on their growth rate; acid resistance additionally contributes to competitiveness in sourdoughs with long fermentation times. Glycerol metabolism via glycerol dehydratase (gupCDE) accelerates growth by the regeneration of reduced cofactors; glutamate metabolism via glutamate decarboxylase (gadB) increas...

  9. Fast growing plantations for wood production – integration of ecological effects and economic perspectives

    Directory of Open Access Journals (Sweden)

    Michael eBredemeier

    2015-06-01

    Full Text Available Biomass crops are perceived as a feasible means to substitute sizeable amounts of fossil fuel in the future. A prospect of CO2 reduction (resp. CO2 neutrality is credited to biomass fuels, and thus a potential contribution to mitigate climate change. Short rotation coppices (SRC with fast growing poplar and willow trees are an option for producing high yields of woody biomass, which is suitable for both energetic and material use. One negative effect that comes along with the establishment of SRC may be a decrease in groundwater recharge, because high rates of transpiration and interception are anticipated. Therefore, it is important to measure, analyse, and model the effects of SRC-planting on landscape water budgets. To analyse the effects on the water budget a poplar SRC plot was studied by measuring hydrological parameters to be used in the hydrological model WaSim. Results reveal very low or even missing ground water recharge for SRC compared to agricultural land use or grassland, especially succeeding dry years. However, this strong effect on plot level is moderated on the larger spatial scale of catchment level, for which the modelling was also performed. In addition to water, nutrient fluxes and budgets were studied. Nitrogen is still a crucial issue in today's agriculture. Intensive fertilization or increased applications of manure from concentrated livestock breeding are often leading to high loads of nitrate leaching, or enhanced N2O emissions to the atmosphere on arable crop fields. SRC or agroforestry systems (AF on former crop land may offer an option to decrease such N losses, while simultaneously producing woody biomass. This is mainly due to the generally smaller N requirements of woody vegetation, which usually entail no need for any fertilization. The trees supply deep and permanent rooting systems, which can be regarded as a safety net to prevent nutrient leaching. Thus, SRC altogether can help to diminish N eutrophication.

  10. Effects of imidacloprid on the ecology of sub-tropical freshwater microcosms.

    Science.gov (United States)

    Sumon, Kizar Ahmed; Ritika, Afifat Khanam; Peeters, Edwin T H M; Rashid, Harunur; Bosma, Roel H; Rahman, Md Shahidur; Fatema, Mst Kaniz; Van den Brink, Paul J

    2018-05-01

    The neonicotinoid insecticide imidacloprid is used in Bangladesh for a variety of crop protection purposes. Imidacloprid may contaminate aquatic ecosystems via spray drift, surface runoff and ground water leaching. The present study aimed at assessing the fate and effects of imidacloprid on structural (phytoplankton, zooplankton, macroinvertebrates and periphyton) and functional (organic matter decomposition) endpoints of freshwater, sub-tropical ecosystems in Bangladesh. Imidacloprid was applied weekly to 16 freshwater microcosms (PVC tanks containing 400 L de-chlorinated tap water) at nominal concentrations of 0, 30, 300, 3000 ng/L over a period of 4 weeks. Results indicated that imidacloprid concentrations from the microcosm water column declined rapidly. Univariate and multivariate analysis showed significant effects of imidacloprid on the zooplankton and macroinvertebrate community, some individual phytoplankton taxa, and water quality variables (i.e. DO, alkalinity, ammonia and nitrate), with Cloeon sp., Diaptomus sp. and Keratella sp. being the most affected species, i.e. showing lower abundance values in all treatments compared to the control. The observed high sensitivity of Cloeon sp. and Diaptomus sp. was confirmed by the results of single species tests. No significant effects were observed on the species composition of the phytoplankton, periphyton biomass and organic matter decomposition for any of the sampling days. Our study indicates that (sub-)tropical aquatic ecosystems can be much more sensitive to imidacloprid compared to temperate ones. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Incorporating anthropogenic effects into trophic ecology: predator–prey interactions in a human-dominated landscape

    Science.gov (United States)

    Dorresteijn, Ine; Schultner, Jannik; Nimmo, Dale G.; Fischer, Joern; Hanspach, Jan; Kuemmerle, Tobias; Kehoe, Laura; Ritchie, Euan G.

    2015-01-01

    Apex predators perform important functions that regulate ecosystems worldwide. However, little is known about how ecosystem regulation by predators is influenced by human activities. In particular, how important are top-down effects of predators relative to direct and indirect human-mediated bottom-up and top-down processes? Combining data on species' occurrence from camera traps and hunting records, we aimed to quantify the relative effects of top-down and bottom-up processes in shaping predator and prey distributions in a human-dominated landscape in Transylvania, Romania. By global standards this system is diverse, including apex predators (brown bear and wolf), mesopredators (red fox) and large herbivores (roe and red deer). Humans and free-ranging dogs represent additional predators in the system. Using structural equation modelling, we found that apex predators suppress lower trophic levels, especially herbivores. However, direct and indirect top-down effects of humans affected the ecosystem more strongly, influencing species at all trophic levels. Our study highlights the need to explicitly embed humans and their influences within trophic cascade theory. This will greatly expand our understanding of species interactions in human-modified landscapes, which compose the majority of the Earth's terrestrial surface. PMID:26336169

  12. It's a bear market: evolutionary and ecological effects of predation on two wild sockeye salmon populations.

    Science.gov (United States)

    Lin, J E; Hard, J J; Naish, K A; Peterson, D; Hilborn, R; Hauser, L

    2016-05-01

    Predation can affect both phenotypic variation and population productivity in the wild, but quantifying evolutionary and demographic effects of predation in natural environments is challenging. The aim of this study was to estimate selection differentials and coefficients associated with brown bear (Ursus arctos) predation in wild sockeye salmon (Oncorhynchus nerka) populations spawning in pristine habitat that is often subject to intense predation pressure. Using reconstructed genetic pedigrees, individual reproductive success (RS) was estimated in two sockeye salmon populations for two consecutive brood years with very different predation intensities across brood years. Phenotypic data on individual adult body length, body depth, stream entry timing and reproductive lifespan were used to calculate selection coefficients based on RS, and genetic variance components were estimated using animal models. Bears consistently killed larger and more recently arrived adults, although selection differentials were small. In both populations, mean RS was higher in the brood year experiencing lower predation intensity. Selection coefficients were similar across brood years with different levels of predation, often indicating stabilizing selection on reproductive lifespan as well as directional selection for longer reproductive lifespan. Despite these selection pressures, genetic covariation of morphology, phenology and lifespan appears to have maintained variation in spawner body size and stream entry timing in both populations. Our results therefore suggest considerable demographic but limited evolutionary effects of bear predation in the two study populations.

  13. Ecological effects of ionizing radiation on population and ecosystem: a computational model ecosystem study

    International Nuclear Information System (INIS)

    Doi, Masahiro; Fuma, Shoichi; Ishii, Nobuyuki; Sakashita, Tetsuya; Miyamoto, Kiriko; Takeda, Hiroshi; Kawabata, Zenichiro

    2003-01-01

    Ecosystem is a self-sustaining system of complexity, and their responses to the impacts are synergistic and subjected to the demographic stochasticity of the species, environmental stochasticity and randomness. Environmental fate and effects of radiation has ranged from observable DNA damage of the cell to the fare on tissues, individual, population, community and ecosystems. The quantitative, systematic individual-based model, SIM-COSM was developed to simulate impacts of radiation exposure and other toxicants on an aquatic microbial ecosystem (microcosm). The microcosm consists of heterotroph ciliate protozoa (Tetrahymena thermophila B) as a consumer, autotroph flagellate algae (Euglena gracilis Z) as a producer and saprotroph bacteria (Escherichia coli DH5) as a decomposer. The symbiosis among microbes is self-organized by realizing material cycle and sustained for more than 2 years after inoculation. The system can not afford to lose any one of the microbes to maintain its sustainability. Experimental ecotoxicological tests for (a) gamma radiation, (b) Manganese ions and (c) Gadolinium are summarized. Population dynamics of microbes in Microcosm and its computer simulations by SIM-COSM are shown together in a figure. Population dynamics in Microcosm and SIM-COSM exposed to 500 Gy of gamma-radiation at 50 days after inoculation are shown also in a figure. To take the effects on the interactions between species and environment into account, one option is to put the ecotoxicity tests as experimental micro ecosystem study and theoretical model ecosystem analysis. (M. Suetake)

  14. Antimicrobial Effect of 15 Medicinal Plant Species and their Dependency on Climatic Conditions of Growth in Different Geographical and Ecological Areas of Fars Province

    Directory of Open Access Journals (Sweden)

    Abbas Abdollahi

    2012-05-01

    Full Text Available Background: The effects of medicinal plants are variable in different conditions. Here, the antimicrobial effect of 15 medicinal plant species and their dependency on the climatic condition of growth in different geographical and ecological areas of Fars Province were studied. Materials and Methods: In This empirical study, the antimicrobial effect of hydro-alcoholic extract of 15 medicinal plant species was examined against standard bacterial strains comparing to conventional therapeutic antibiotics using disk diffusion assay and serial broth dilution. Results: All Extracts were effective against S.aureus ATCC 25923 growth; also Peganum harmala, Myrtus communis, Mentha pulegium, Mentha spp, and Zataria multiflora extracts were observed to have antimicrobial activity against E.coli ATCC 25922. This antimicrobial activity had partially similar results, comparing to conventional antibioticsConclusion: Medicinal plants produce various amounts of antimicrobial substances under the climatic and ecological conditions of each zone, which must be considered in manufacturing herbal medicines.

  15. GNP - an ecological catastrophe?

    International Nuclear Information System (INIS)

    Lejon, E.

    1996-01-01

    In this chapter of the book author deals with the ecological aspects of the Gabcikovo-Nagymaros Project (GNP) as well as other projects on the European rivers. Ground water levels profiles are presented. Effects of the GNP on the forests, flora, and fauna are discussed. The conditions for delta region protection are presented. Chemical and radioactive contamination, as well as their synergistic effects are discussed

  16. A 3-level Bayesian mixed effects location scale model with an application to ecological momentary assessment data.

    Science.gov (United States)

    Lin, Xiaolei; Mermelstein, Robin J; Hedeker, Donald

    2018-06-15

    Ecological momentary assessment studies usually produce intensively measured longitudinal data with large numbers of observations per unit, and research interest is often centered around understanding the changes in variation of people's thoughts, emotions and behaviors. Hedeker et al developed a 2-level mixed effects location scale model that allows observed covariates as well as unobserved variables to influence both the mean and the within-subjects variance, for a 2-level data structure where observations are nested within subjects. In some ecological momentary assessment studies, subjects are measured at multiple waves, and within each wave, subjects are measured over time. Li and Hedeker extended the original 2-level model to a 3-level data structure where observations are nested within days and days are then nested within subjects, by including a random location and scale intercept at the intermediate wave level. However, the 3-level random intercept model assumes constant response change rate for both the mean and variance. To account for changes in variance across waves, as well as clustering attributable to waves, we propose a more comprehensive location scale model that allows subject heterogeneity at baseline as well as across different waves, for a 3-level data structure where observations are nested within waves and waves are then further nested within subjects. The model parameters are estimated using Markov chain Monte Carlo methods. We provide details on the Bayesian estimation approach and demonstrate how the Stan statistical software can be used to sample from the desired distributions and achieve consistent estimates. The proposed model is validated via a series of simulation studies. Data from an adolescent smoking study are analyzed to demonstrate this approach. The analyses clearly favor the proposed model and show significant subject heterogeneity at baseline as well as change over time, for both mood mean and variance. The proposed 3-level

  17. Physiological and ecological effects of increasing temperature on fish production in lakes of Arctic Alaska

    Science.gov (United States)

    Carey, Michael P.; Zimmerman, Christian E.

    2014-01-01

    Lake ecosystems in the Arctic are changing rapidly due to climate warming. Lakes are sensitive integrators of climate-induced changes and prominent features across the Arctic landscape, especially in lowland permafrost regions such as the Arctic Coastal Plain of Alaska. Despite many studies on the implications of climate warming, how fish populations will respond to lake changes is uncertain for Arctic ecosystems. Least Cisco (Coregonus sardinella) is a bellwether for Arctic lakes as an important consumer and prey resource. To explore the consequences of climate warming, we used a bioenergetics model to simulate changes in Least Cisco production under future climate scenarios for lakes on the Arctic Coastal Plain. First, we used current temperatures to fit Least Cisco consumption to observed annual growth. We then estimated growth, holding food availability, and then feeding rate constant, for future projections of temperature. Projected warmer water temperatures resulted in reduced Least Cisco production, especially for larger size classes, when food availability was held constant. While holding feeding rate constant, production of Least Cisco increased under all future scenarios with progressively more growth in warmer temperatures. Higher variability occurred with longer projections of time mirroring the expanding uncertainty in climate predictions further into the future. In addition to direct temperature effects on Least Cisco growth, we also considered changes in lake ice phenology and prey resources for Least Cisco. A shorter period of ice cover resulted in increased production, similar to warming temperatures. Altering prey quality had a larger effect on fish production in summer than winter and increased relative growth of younger rather than older age classes of Least Cisco. Overall, we predicted increased production of Least Cisco due to climate warming in lakes of Arctic Alaska. Understanding the implications of increased production of Least Cisco to

  18. Ecological effects of combined pollution associated with e-waste recycling on the composition and diversity of soil microbial communities.

    Science.gov (United States)

    Liu, Jun; He, Xiao-Xin; Lin, Xue-Rui; Chen, Wen-Ce; Zhou, Qi-Xing; Shu, Wen-Sheng; Huang, Li-Nan

    2015-06-02

    The crude processing of electronic waste (e-waste) has led to serious contamination in soils. While microorganisms may play a key role in remediation of the contaminated soils, the ecological effects of combined pollution (heavy metals, polychlorinated biphenyls, and polybrominated diphenyl ethers) on the composition and diversity of microbial communities remain unknown. In this study, a suite of e-waste contaminated soils were collected from Guiyu, China, and the indigenous microbial assemblages were profiled by 16S rRNA high-throughput sequencing and clone library analysis. Our data revealed significant differences in microbial taxonomic composition between the contaminated and the reference soils, with Proteobacteria, Acidobacteria, Bacteroidetes, and Firmicutes dominating the e-waste-affected communities. Genera previously identified as organic pollutants-degrading bacteria, such as Acinetobacter, Pseudomonas, and Alcanivorax, were frequently detected. Canonical correspondence analysis revealed that approximately 70% of the observed variation in microbial assemblages in the contaminated soils was explained by eight environmental variables (including soil physiochemical parameters and organic pollutants) together, among which moisture content, decabromodiphenyl ether (BDE-209), and copper were the major factors. These results provide the first detailed phylogenetic look at the microbial communities in e-waste contaminated soils, demonstrating that the complex combined pollution resulting from improper e-waste recycling may significantly alter soil microbiota.

  19. Effect of cardiovascular prevention strategies on incident coronary disease hospitalisation rates in Spain; an ecological time series analysis.

    Science.gov (United States)

    Medrano, María José; Alcalde-Cabero, Enrique; Ortíz, Cristina; Galán, Iñaki

    2014-02-17

    To assess the overall population impact of primary prevention strategies (promotion of healthy lifestyles, prevention of smoking and use of vascular risk drug therapy) of coronary disease in Spain. Ecological time series analysis, 1982-2009. All public and private hospitals in Spain. General population. Incident coronary disease hospitalisation as derived from official hospital discharge data. Annual hospitalisation rates were modelled according to nationwide use of statins, antihypertensive, antidiabetic and antiplatelet drugs, and prevalences of smoking, obesity and overweight. Additive generalised models and mixed Poisson regression models were used for the purpose, taking year as the random-effect variable and adjusting for age, sex, prevalence of vascular risk factors and the number of hospital beds in intensive and coronary care units. Across 28 years and 671.5 million person-years of observation, there were 2 986 834 hospitalisations due to coronary disease; of these, 1 441 980 (48.28%) were classified as incident. Hospitalisation rates increased from 1982 to 1996, with an inflection point in 1997 and a subsequent 52% decrease until 2009. Prevalences of smoking, obesity, overweight and use of vascular risk drug therapy were significantly associated with hospitalisation rates (pcrisis. Future strategies ought to lay special stress on excessive body weight prevention.

  20. Assessment of the effect of anthropogenic pollution on the ecology of small shallow lakes using the palaeolimnological approach

    Directory of Open Access Journals (Sweden)

    Tiiu Koff

    2016-11-01

    Full Text Available Palaeolimnological techniques were utilized to determine the extent of the effect of anthropogenic pollutants or other environmental stressors on three lake ecosystems over the last 200 years. The ecology of the study sites has experienced significant changes due to various activities such as (1 extensive catchment drainage and using poisoning as a fish management measure, (2 seepage of urban waste water due to establishment and growth of a town and (3 artificial inflow of oil-shale mining waters. Sediment geochemical composition, fossil pigments and Cladocera remains from the sediment cores were analysed to demonstrate that sufficient information can be derived from sediments to permit a historical reconstruction. The integrated use of archival maps, historical records and lake monitoring data confirmed links to anthropogenic pollutants, primarily on the catchment level. The examples show how the sediment indicators provide unique insights into the causes and temporal dynamics of lake ecosystem changes relevant for environmental management decisions. This study demonstrates that palaeolimnology has great potential to assist in eutrophication assessment and management efforts in waterbodies.

  1. Ecological effects of pipeline construction through deciduous forested wetlands, Midland County, Michigan. Topical report, October 1990--August 1992

    Energy Technology Data Exchange (ETDEWEB)

    Rastorfer, J.R. [Chicago State Univ., IL (United States). Dept. of Biological Sciences; Van Dyke, G.D.; Zellmer, S.D.; Wilkey, P.L. [Argonne National Lab., IL (United States)

    1995-04-01

    This study is designed to record vegetational changes induced by the construction of a large-diameter gas pipeline through deciduous forested wetlands. Two second-growth wetland sites mapped Lenawee soils were selected in Midland County, Michigan: Site 1, a younger stand subjected to recent selective logging, and Site 2, a more mature stand. The collection of ecological data to analyze plant succession on the right-of-way (ROW) and the effects of the developing ROW plant communities on adjacent forest communities was initiated in 1989. Cover class estimates were made for understory and ROW plant species on the basis of 1 {times} 1{minus}m quadrats. Individual stem diameters and species counts were recorded for overstory plants in 10{minus}m quadrats. Although long-term studies have not been completed, firm baseline data were established for comparative analyses with future sampling. Current data indicate that vegetation became well-established on the ROW within one year and subsequently increased in coverage. About 65% of the species were wetland indicators, and the dominants included seeded and natural invading species; nevertheless, some elements of the original flora regenerated and persist. The plants of the ecotone understories of both sites changed from their original composition as a result of the installation of the gas pipeline. Although some forest species persist at both sites, the ecotone of Site I was influenced more by the seeded species, whereas the natural invaders were more important at Site 2.

  2. Effects on water, soil and vegetation of an increasing atmospheric supply of sulfur: a survey on ecological bases

    Energy Technology Data Exchange (ETDEWEB)

    Malmer, N; Nilsson, F M.I.

    1974-01-01

    In this paper a critical survey is given of the research work carried out on the ecological effects of the increasing rate of sulfur deposition, especially with reference to Swedish conditions. It also contains information about soil types and soil conditions of importance for the understanding of the problems. In several lakes and rivers this increased supply of sulfur (mainly as SO/sub 4//sup 2 -/) has brought about a considerable decrease in pH. In most lakes and rivers of the oligotrophic type the concentration of bicarbonate ion (the main buffer of pH changes) was already low, and it has now been reduced to the extent that a further increase in the deposition of sulfate will immediately result in marked and much more widespread acidification. The increase in the supply of sulfur which has already occurred will influence the conditions of the soil in several ways. A distinct decrease in forest productivity is to be expected. Due to the short time that has passed since the supply of sulfur started to increase it is, however, doubtful whether such a decrease is yet measurable with the measurement methods commonly used in forest taxation. 88 references.

  3. Ecological carryover effects associated with partial migration in white perch (Morone americana) within the Hudson River Estuary

    Science.gov (United States)

    Gallagher, Brian K.; Piccoli, Philip M.; Secor, David H.

    2018-01-01

    Partial migration in complex life cycles allows environmental conditions experienced during one life-stage to interact with genetic thresholds and produce divergent spatial behaviors in the next stage. We evaluated partial migration over the entire life cycle of white perch, (Morone americana) within the Hudson River Estuary, combining otolith microchemistry, population demographics and environmental data analysis. Ecological carryover effects were used as a framework to test how environmental variation during the larval period influenced migration behaviors and growth characteristics in subsequent life-stages. Two annual cohorts of juveniles were classified based on whether they persisted in natal habitats (freshwater resident contingent) or dispersed into non-natal habitats (brackish water migratory contingent) as juveniles. The migratory contingent tended to hatch earlier and experience cooler temperatures as larvae, while the availability of zooplankton prey during the larval period appeared to influence growth dynamics before and after metamorphosis. Juvenile migration behaviors were reversible but usually persisted into adulthood. As juveniles, the consequences of partial migration on growth appeared to be modified by river flow, as demonstrated by the influence of a large storm event on feeding conditions in one of the study years. Migratory adults grew faster and attained larger maximum sizes, but may also experience higher rates of mortality. The interplay uncovered between life-stage transitions, conditional migration behaviors and habitat productivity throughout the life cycle shapes white perch population dynamics and will likely play an important role in responses to long-term environmental change.

  4. Assessing triclosan-induced ecological and trans-generational effects in natural phytoplankton communities: a trait-based field method.

    Science.gov (United States)

    Pomati, Francesco; Nizzetto, Luca

    2013-07-01

    We exposed replicated phytoplankton communities confined in semi-permeable membrane-based mesocosms to 0, 0.1, 1 and 10 μg L(-1) triclosan (TCS) and placed them back in their original environment to investigate the occurrence of trans-generational responses at individual, population and community levels. TCS diffused out of mesocosms with a half-life of less than 8 h, so that only the parental generation was directly stressed. At the beginning of the experiment and after 7 days (approximately 2 generations) we analysed responses in the phytoplankton using scanning flow-cytometry. We acquired information on several individually expressed phenotypic traits, such as size, biovolume, pigment fluorescence and packaging, for thousands of individuals per replicated population and derived population and community aggregated traits. We found significant changes in community functioning (increased productivity in terms of biovolume and total fluorescence), with maximal effects at 1 μg L(-1) TCS. We detected significant and dose-dependent responses on population traits, such as changes in abundance for several populations, increased average size and fluorescence of cells, and strong changes in within-population trait mean and variance (suggesting micro-evolutionary effects). We applied the Price equation approach to partition community effects (changes in biovolume or fluorescence) in their physiological and ecological components, and quantified the residual component (including also evolutionary responses). Our results suggested that evolutionary or inheritable phenotypic plasticity responses may represent a significant component of the total observed change following exposure and over relatively small temporal scales.

  5. Implication of Forest-Savanna Dynamics on Biomass and Carbon Stock: Effectiveness of an Amazonian Ecological Station

    Science.gov (United States)

    Couto-Santos, F. R.; Luizao, F. J.

    2014-12-01

    The forests-savanna advancement/retraction process seems to play an important role in the global carbon cycle and in the climate-vegetation balance maintenance in the Amazon. To contribute with long term carbon dynamics and assess effectiveness of a protected area in reduce carbon emissions in Brazilian Amazon transitional areas, variations in forest-savanna mosaics biomass and carbon stock within Maraca Ecological Station (MES), Roraima/Brazil, and its outskirts non-protected areas were compared. Composite surface soil samples and indirect methods based on regression models were used to estimate aboveground tree biomass accumulation and assess vegetation and soil carbon stock along eleven 0.6 ha transects perpendicular to the forest-savanna limits. Aboveground biomass and carbon accumulation were influenced by vegetation structure, showing higher values within protected area, with great contribution of trees above 40 cm in diameter. In the savanna environments of protected areas, a higher tree density and carbon stock up to 30 m from the border confirmed a forest encroachment. This pointed that MES acts as carbon sink, even under variations in soil fertility gradient, with a potential increase of the total carbon stock from 9 to 150 Mg C ha-1. Under 20 years of fire and disturbance management, the results indicated the effectiveness of this protected area to reduce carbon emissions and mitigate greenhouse and climate change effects in a forest-savanna transitional area in Brazilian Northern Amazon. The contribution of this study in understanding rates and reasons for biomass and carbon variation, under different management strategies, should be considered the first approximation to assist policies of reducing emissions from deforestation and forest degradation (REDD) from underresearched Amazonian ecotone; despite further efforts in this direction are still needed. FINANCIAL SUPPORT: Boticário Group Foundation (Fundação Grupo Boticário); National Council for

  6. Ecological effects of pipeline construction through deciduous forested wetlands, Midland County, Michigan

    International Nuclear Information System (INIS)

    Zellmer, S.D.; Rastorfer, J.R.; Van Dyke, G.D.

    1991-07-01

    Implementation of recent federal and state regulations promulgated to protect wetlands makes information on effects of gas pipeline rights-of-way (ROWs) in wetlands essential to the gas pipeline industry. This study is designed to record vegetational changes induced by the construction of a large-diameter gas pipeline through deciduous forested wetlands. Two second-growth forested wetland sites mapped as Lenawee soils, one mature and one subjected to recent selective logging, were selected in Midland County, Michigan. Changes in the adjacent forest and successional development on the ROW are being documented. Cover-class estimates are being made for understory and ROW plant species using 1 x1-m quadrats. Counts are also being made for all woody species with stems < 2 cm in diameter at breast height (dbh) in the same plots used for cover-class estimates. Individual stem diameters and species counts are being recorded for all woody understory and overstory plants with stems ≥2 cm dbh in 10 x 10-m plots. Although analyses of the data have not been completed, preliminary analyses indicate that some destruction of vegetation at the ROW forest edge may have been avoidable during pipeline construction. Rapid regrowth of many native wetland plant species on the ROW occurred because remnants of native vegetation and soil-bearing propagules of existing species survived on the ROW after pipeline construction and seeding operations. 91 refs., 11 figs., 3 tabs

  7. Testing the cleaning effectiveness of new ecological aqueous dispersions applied on old icons

    Science.gov (United States)

    Vasilache, Viorica; Sandu, Irina Crina Anca; Pruteanu, Silvea; Caldeira, Ana Teresa; Simionescu, Atena Elena; Sandu, Ion

    2016-03-01

    Adherent deposits are very aggressive towards ancient heritage paintings since they affect the varnish and the painting's layers, sometimes reaching the preparative layers. The biggest problem to the restorer is their removal without affecting the patina, the transparent varnish (well preserved) and fine colour glazes made during painting. Therefore, their removal requires preliminary cleaning tests that allow the optimization of the cleaning system composition that is going to be used. The study was focused on organic natural systems, as colourless supernatants, some of them used during ages, but insufficiently studied. The paper presents an evaluation of the effectiveness of cleaning varnished icons of the nineteenth century, with complex conservation cases using supernatants derived from aqueous dispersions extracted from vegetables and dry indigenous herbal infusions. Best results, after six consecutive cleaning steps, on tempera old icon was obtained for a mixture made of mature white onion juice + extract of Soapwort flowers + corn silk tea + acacia tea. As a best result after just one cleaning step was obtained for a quaternary mixture composed from mature white onion juice + mature carrot juice + corn silk tea + aqueous extract of Soapwort flowers.

  8. Ecological effects of pipeline construction through deciduous forested wetlands, Midland County, Michigan

    Energy Technology Data Exchange (ETDEWEB)

    Zellmer, S.D. (Argonne National Lab., IL (United States)); Rastorfer, J.R. (Chicago State Univ., IL (United States). Dept. of Biological Sciences ANL/CSU Cooperative Herbarium, Chicago, IL (United States)); Van Dyke, G.D. (Trinity Christian Coll., Palos Heights, IL (United States). Dept. of Biology)

    1991-07-01

    Implementation of recent federal and state regulations promulgated to protect wetlands makes information on effects of gas pipeline rights-of-way (ROWs) in wetlands essential to the gas pipeline industry. This study is designed to record vegetational changes induced by the construction of a large-diameter gas pipeline through deciduous forested wetlands. Two second-growth forested wetland sites mapped as Lenawee soils, one mature and one subjected to recent selective logging, were selected in Midland County, Michigan. Changes in the adjacent forest and successional development on the ROW are being documented. Cover-class estimates are being made for understory and ROW plant species using 1 {times}1-m quadrats. Counts are also being made for all woody species with stems < 2 cm in diameter at breast height (dbh) in the same plots used for cover-class estimates. Individual stem diameters and species counts are being recorded for all woody understory and overstory plants with stems {ge}2 cm dbh in 10 {times} 10-m plots. Although analyses of the data have not been completed, preliminary analyses indicate that some destruction of vegetation at the ROW forest edge may have been avoidable during pipeline construction. Rapid regrowth of many native wetland plant species on the ROW occurred because remnants of native vegetation and soil-bearing propagules of existing species survived on the ROW after pipeline construction and seeding operations. 91 refs., 11 figs., 3 tabs.

  9. Ecological Effects of Roads on the Plant Diversity of Coastal Wetland in the Yellow River Delta

    Directory of Open Access Journals (Sweden)

    Yunzhao Li

    2014-01-01

    Full Text Available The 26 sample sites in 7 study plots adjacent to asphalt road and earth road in coastal wetland in the Yellow River Delta were selected to quantify plant diversity using quadrat sampling method in plant bloom phase of July and August 2012. The indice of βT and Jaccard’s coefficient were applied to evaluate the species diversity. The results showed that the plant diversities and alien plants were high in the range of 0–20 m to the road verge. There were more exotics and halophytes in plots of asphalt roadside than that of earth roadside. However, proportion of halophytes in habitats of asphalt roadsides was lower than that of earth roadside. By comparing β-diversity, there were more common species in the asphalt roadsides than that in the earth roadsides. The similarity of plant communities in studied plots of asphalt roadsides and earth roadsides increased with increasing the distance to road verge. The effect range of roads for plant diversity in study region was about 20 m to road verge. Our results indicate that the construction and maintenance of roads in wetland could increase the plant species diversities of communities and risk of alien species invasion.

  10. Ecological strategies in california chaparral: Interacting effects of soils, climate, and fire on specific leaf area

    Science.gov (United States)

    Anacker, Brian; Rajakaruna, Nishanta; Ackerly, David; Harrison, Susan; Keeley, Jon E.; Vasey, Michael

    2011-01-01

    Background: High values of specific leaf area (SLA) are generally associated with high maximal growth rates in resource-rich conditions, such as mesic climates and fertile soils. However, fire may complicate this relationship since its frequency varies with both climate and soil fertility, and fire frequency selects for regeneration strategies (resprouting versus seeding) that are not independent of resource-acquisition strategies. Shared ancestry is also expected to affect the distribution of resource-use and regeneration traits.Aims: We examined climate, soil, and fire as drivers of community-level variation in a key functional trait, SLA, in chaparral in California.Methods: We quantified the phylogenetic, functional, and environmental non-independence of key traits for 87 species in 115 plots.Results: Among species, SLA was higher in resprouters than seeders, although not after phylogeny correction. Among communities, mean SLA was lower in harsh interior climates, but in these climates it was higher on more fertile soils and on more recently burned sites; in mesic coastal climates, mean SLA was uniformly high despite variation in soil fertility and fire history.Conclusions: We conclude that because important correlations exist among both species traits and environmental filters, interpreting the functional and phylogenetic structure of communities may require an understanding of complex interactive effects.

  11. Ecological effects of contaminants in McCoy Branch, 1989-1990

    Energy Technology Data Exchange (ETDEWEB)

    Ryon, M.G. (ed.)

    1992-01-01

    The 1984 Hazardous and Solid Waste Amendments to the Resource Conservation and Recovery Act (RCRA) required assessment of all current and former solid waste management units. Such a RCRA Facility Investigation (RFI) was required of the Y-12 Plant for their Filled Coal Ash Pond on McCoy Branch. Because the disposal of coal ash in the ash pond, McCoy Branch, and Rogers Quarry was not consistent with the Tennessee Water Quality Act, several remediation steps were implemented or planned for McCoy Branch to address disposal problems. The McCoy Branch RFI plan included provisions for biological monitoring of the McCoy Branch watershed. The objectives of the biological monitoring were to: (1) document changes in biological quality of McCoy Branch after completion of a pipeline and after termination of all discharges to Rogers Quarry, (2) provide guidance on the need for additional remediation, and (3) evaluate the effectiveness of implemented remedial actions. The data from the biological monitoring program will also determine if the classified uses, as identified by the State of Tennessee, of McCoy Branch are being protected and maintained. This report discusses results from toxicity monitoring of snails fish community assessment, and a Benthic macroinvertebrate community assessment.

  12. Screening for EIA in India: enhancing effectiveness through ecological carrying capacity approach.

    Science.gov (United States)

    Rajaram, T; Das, Ashutosh

    2011-01-01

    Developing countries across the world have embraced the policy of high economic growth as a means to reduce poverty. This economic growth largely based on industrial output is fast degrading the ecosystems, jeopardizing their long term sustainability. Environmental Impact Assessment (EIA) has long been recognized as a tool which can help in protecting the ecosystems and aid sustainable development. The Screening guidelines for EIA reflect the level of commitment the nation displays towards tightening its environmental protection system. The paper analyses the screening process for EIA in India and dissects the rationale behind the exclusions and thresholds set in the screening process. The screening process in India is compared with that of the European Union with the aim of understanding the extent of deviations from a screening approach in the context of better economic development. It is found that the Indian system excludes many activities from the purview of screening itself when compared to the EU. The constraints responsible for these exclusions are discussed and the shortcomings of the current command and control system of environmental management in India are also explained. It is suggested that an ecosystem carrying capacity based management system can provide significant inputs to enhance the effectiveness of EIA process from screening to monitoring. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. Ecological Effects of Roads on the Plant Diversity of Coastal Wetland in the Yellow River Delta

    Science.gov (United States)

    Li, Yunzhao; Du, Siyao; Han, Guangxuan; Qu, Fanzhu; Wang, Guangmei; Fu, Yuqin; Zhan, Chao

    2014-01-01

    The 26 sample sites in 7 study plots adjacent to asphalt road and earth road in coastal wetland in the Yellow River Delta were selected to quantify plant diversity using quadrat sampling method in plant bloom phase of July and August 2012. The indice of β T and Jaccard's coefficient were applied to evaluate the species diversity. The results showed that the plant diversities and alien plants were high in the range of 0–20 m to the road verge. There were more exotics and halophytes in plots of asphalt roadside than that of earth roadside. However, proportion of halophytes in habitats of asphalt roadsides was lower than that of earth roadside. By comparing β-diversity, there were more common species in the asphalt roadsides than that in the earth roadsides. The similarity of plant communities in studied plots of asphalt roadsides and earth roadsides increased with increasing the distance to road verge. The effect range of roads for plant diversity in study region was about 20 m to road verge. Our results indicate that the construction and maintenance of roads in wetland could increase the plant species diversities of communities and risk of alien species invasion. PMID:25147872

  14. Effect of Dietary Protein Levels on Composition of Odorous Compounds and Bacterial Ecology in Pig Manure

    Directory of Open Access Journals (Sweden)

    Sungback Cho

    2015-09-01

    Full Text Available This study was performed to investigate the effect of different levels of dietary crude protein (CP on composition of odorous compounds and bacterial communities in pig manure. A total of 48 male pigs (average initial body weight 45 kg fed diets containing three levels of dietary CP (20%, 17.5%, and 15% and their slurry samples were collected from the pits under the floor every week for one month. Changes in composition of odorous compounds and bacterial communities were analyzed by gas chromatography and 454 FLX titanium pyrosequencing systems, respectively. Levels of phenols, indoles, short chain fatty acid and branched chain fatty acid were lowest (p<0.05 in CP 15% group among three CP levels. Relative abundance of Bacteroidetes phylum and bacterial genera including Leuconostoc, Bacillus, Atopostipes, Peptonphilus, Ruminococcaceae_uc, Bacteroides, and Pseudomonas was lower (p<0.05 in CP 15% than in CP 20% group. There was a positive correlation (p<0.05 between odorous compounds and bacterial genera: phenol, indole, iso-butyric acid, and iso-valeric acid with Atopostipes, p-cresol and skatole with Bacteroides, acetic acid and butyric acid with AM982595_g of Porphyromonadaceae family, and propionic acid with Tissierella. Taken together, administration of 15% CP showed less production of odorous compounds than 20% CP group and this result might be associated with the changes in bacterial communities especially whose roles in protein metabolism.

  15. Characterization of the effects of macronutrient deficiencies in mangabeira seedlings

    Directory of Open Access Journals (Sweden)

    Layara Alexandre Bessa

    2012-12-01

    Full Text Available Knowledge of the mineral nutrition requirements of mangabeira (Hancornia speciosa Gomes is relatively scarce and rudimentary because there is a lack of consistent data concerning its nutritional demands at different developmental stages. The aim of this research was to characterize the visual symptoms of macronutrient deficiencies and to evaluate the effects of these deficiencies on the growth, the production of dry matter, and the leaf content of mangabeira. To achieve this goal, a greenhouse experiment was conducted at the Goiano Federal Institute (Instituto Federal Goiano in Rio Verde - GO, from January to June 2011 in which mangabeira plants were arranged in a random block design and grown in nutrient solutions. This experiment was replicated four times. The plants were treated with either a complete nutrient solution or a nutrient solution from which the individual macronutrient of interest (nitrogen (N, phosphorous (P, potassium (K, magnesium (Mg, calcium (Ca, or sulfur (S had been omitted. The omission of a macronutrient from the nutrient solution resulted in morphological alterations that were characteristic symptoms of the particular nutritional deficiency and caused decreases in growth and dry matter mass production. The accumulation of macronutrients displayed the following order in mangabeira leaves: N>K>Ca>P>S>Mg.

  16. Effective dielectric mixture model for characterization of diesel contaminated soil

    International Nuclear Information System (INIS)

    Al-Mattarneh, H.M.A.

    2007-01-01

    Human exposure to contaminated soil by diesel isomers can have serious health consequences like neurological diseases or cancer. The potential of dielectric measuring techniques for electromagnetic characterization of contaminated soils was investigated in this paper. The purpose of the research was to develop an empirical dielectric mixture model for soil hydrocarbon contamination application. The paper described the basic theory and elaborated in dielectric mixture theory. The analytical and empirical models were explained in simple algebraic formulas. The experimental study was then described with reference to materials, properties and experimental results. The results of the analytical models were also mathematically explained. The proposed semi-empirical model was also presented. According to the result of the electromagnetic properties of dry soil contaminated with diesel, the diesel presence had no significant effect on the electromagnetic properties of dry soil. It was concluded that diesel had no contribution to the soil electrical conductivity, which confirmed the nonconductive character of diesel. The results of diesel-contaminated soil at saturation condition indicated that both dielectric constant and loss factors of soil were decreased with increasing diesel content. 15 refs., 2 tabs., 9 figs

  17. Characterization of non equilibrium effects on high quality critical flows

    International Nuclear Information System (INIS)

    Camelo, E.; Lemonnier, H.; Ochterbeck, J.

    1995-01-01

    The appropriate design of various pieces of safety equipment such as relief systems, relies on the accurate description of critical flow phenomena. Most of the systems of industrial interest are willing to be described by one-dimensional area-averaged models and a large fraction of them involves multi-component high gas quality flows. Within these circumstances, the flow is very likely to be of an annular dispersed nature and its description by two-fluid models requires various closure relations. Among the most sensitive closures, there is the interfacial area and the liquid entrained fraction. The critical flowrate depends tremendously on the accurate description of the non equilibrium which results from the correctness of the closure equations. In this study, two-component flows are emphasized and non equilibrium results mainly form the differences in the phase velocities. It is therefore of the utmost importance to have reliable data to characterize non equilibrium phenomena and to assess the validity of the closure models. A comprehensive description of air-water nozzle flows, with emphasis on the effect of the nozzle geometry, has been undertaken and some of the results are presented here which helps understanding the overall flow dynamics. Besides the critical flowrate, the presented material includes pressure profiles, droplet size and velocity, liquid film flowrate and liquid film thickness

  18. Characterization of non equilibrium effects on high quality critical flows

    Energy Technology Data Exchange (ETDEWEB)

    Camelo, E.; Lemonnier, H.; Ochterbeck, J. [Commissariat a l Energie Atomique, Grenoble (France)] [and others

    1995-09-01

    The appropriate design of various pieces of safety equipment such as relief systems, relies on the accurate description of critical flow phenomena. Most of the systems of industrial interest are willing to be described by one-dimensional area-averaged models and a large fraction of them involves multi-component high gas quality flows. Within these circumstances, the flow is very likely to be of an annular dispersed nature and its description by two-fluid models requires various closure relations. Among the most sensitive closures, there is the interfacial area and the liquid entrained fraction. The critical flowrate depends tremendously on the accurate description of the non equilibrium which results from the correctness of the closure equations. In this study, two-component flows are emphasized and non equilibrium results mainly form the differences in the phase velocities. It is therefore of the utmost importance to have reliable data to characterize non equilibrium phenomena and to assess the validity of the closure models. A comprehensive description of air-water nozzle flows, with emphasis on the effect of the nozzle geometry, has been undertaken and some of the results are presented here which helps understanding the overall flow dynamics. Besides the critical flowrate, the presented material includes pressure profiles, droplet size and velocity, liquid film flowrate and liquid film thickness.

  19. Media Ecology

    Directory of Open Access Journals (Sweden)

    Marina Ašković

    2015-05-01

    Full Text Available Does the trend in which electronic media are gradually becoming extension of human body have to move towards full enslavement of a human and his personality, or the same human will unpredictably, with the aid of his personal media literacy, exit the whirls of media and technological censorships? Personality crisis is closely related to the crisis of language no matter how contradicted to global ideology of transnational transhumanism it may seem. Considering the fact that recent media presentations of the world are based on commercialization of environmentalism, philosophical and aesthetic thought appears as an important subject of ecology. As media mediates, the scenery of civilized living increasingly becomes more appealing even though it derives from commercial and political background. Consequently, the future of humanity depends by large on the philosophy of media. Media have to truly ecologise returning the humanum to its essence making it into the extension of the natural world.

  20. Fynbos ecology: a preliminary synthesis

    CSIR Research Space (South Africa)

    Day, J

    1979-12-01

    Full Text Available Current knowledge and thinking on the ecology of the Mediterranean type sclerophyll shrublands and heath lands of the southern and south-western Cape is reviewed in 13 concise syntheses. The Fynbos Biome is defined and characterized in terms...

  1. Effect of ecological surface treatment method on friction strength properties of nettle (urtica dioica) fibre yarns

    Science.gov (United States)

    Şansal, S.; Mıstık, S. I.; Fettahov, R.; Ovalı, S.; Duman, M.

    2017-10-01

    Over the last few decades, more attention is given to lignocellulose based fibres as reinforcement material in the polymer composites owing to the environmental pollution caused by the extensive usage of synthetic and inorganic fibres. Developing new natural fibre reinforced composites is the focus of many researches nowadays. They are made from renewable resources and they have less environmental effect in comparison to inorganic fibre reinforced composites. The interest of consumers in eco-friendly natural fibres and textiles has increased in recent years. Unlike inorganic fibres, natural fibres present light weight, high strength/density ratio and are readily available, environmentally friendly and biodegradable. Many different types of natural fibres are exploited for the production of biodegradable polymer composites. The nettle (Urtica dioica L.) is a well-known plant growing on rural sites of Europe, Asia, and North America. Nettle plant contains fibre similar to hemp and flax. However, similar to other natural fibres, nettle fibres are poorly compatible with the thermoplastic matrix of composites, due to their hydrophilic character which reduces mechanical properties of nettle fibre reinforced thermoplastics. In order to improve the fibrematrix adhesion of the natural fibre reinforced composites, surface treatment processes are applied to the lignocellulose fibres. In this study nettle (urtica dioica) fibre yarns were treated with NaOH by using conventional, ultrasonic and microwave energy methods. After treatment processes tensile strength, elongation, friction strength and SEM observations of the nettle fibre yarns were investigated. All treatment processes were improved the tensile strength, elongation and friction strength properties of the nettle fibre yarns. Also higher tensile strength, elongation and friction strength properties were obtained from treated nettle fibre yarns which treated by using microwave energy method.

  2. Effect of lineage-specific metabolic traits of Lactobacillus reuteri on sourdough microbial ecology.

    Science.gov (United States)

    Lin, Xiaoxi B; Gänzle, Michael G

    2014-09-01

    This study determined the effects of specific metabolic traits of Lactobacillus reuteri on its competitiveness in sourdoughs. The competitiveness of lactobacilli in sourdough generally depends on their growth rate; acid resistance additionally contributes to competitiveness in sourdoughs with long fermentation times. Glycerol metabolism via glycerol dehydratase (gupCDE) accelerates growth by the regeneration of reduced cofactors; glutamate metabolism via glutamate decarboxylase (gadB) increases acid resistance by generating a proton motive force. Glycerol and glutamate metabolisms are lineage-specific traits in L. reuteri; therefore, this study employed glycerol dehydratase-positive sourdough isolates of human-adapted L. reuteri lineage I, glutamate decarboxylase-positive strains of rodent-adapted L. reuteri lineage II, as well as mutants with deletions in gadB or gupCDE. The competitivenesses of the strains were quantified by inoculation of wheat and sorghum sourdoughs with defined strains, followed by propagation of doughs with a 10% inoculum and 12-h or 72-h fermentation cycles. Lineage I L. reuteri strains dominated sourdoughs propagated with 12-h fermentation cycles; lineage II L. reuteri strains dominated sourdoughs propagated with 72-h fermentation cycles. L. reuteri 100-23ΔgadB was outcompeted by its wild-type strain in sourdoughs fermented with 72-h fermentation cycles; L. reuteri FUA3400ΔgupCDE was outcompeted by its wild-type strain in sourdoughs fermented with both 12-h and 72-h fermentation cycles. Competition experiments with isogenic pairs of strains resulted in a constant rate of strain displacement of the less competitive mutant strain. In conclusion, lineage-specific traits of L. reuteri determine the competitiveness of this species in sourdough fermentations. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  3. Effects of spatial subsidies and habitat structure on the foraging ecology and size of geckos.

    Directory of Open Access Journals (Sweden)

    Amy A Briggs

    Full Text Available While it is well established that ecosystem subsidies--the addition of energy, nutrients, or materials across ecosystem boundaries--can affect consumer abundance, there is less information available on how subsidy levels may affect consumer diet, body condition, trophic position, and resource partitioning among consumer species. There is also little information on whether changes in vegetation structure commonly associated with spatial variation in subsidies may play an important role in driving consumer responses to subsidies. To address these knowledge gaps, we studied changes in abundance, diet, trophic position, size, and body condition of two congeneric gecko species (Lepidodactylus spp. that coexist in palm dominated and native (hereafter dicot dominated forests across the Central Pacific. These forests differ strongly both in the amount of marine subsidies that they receive from seabird guano and carcasses, and in the physical structure of the habitat. Contrary to other studies, we found that subsidy level had no impact on the abundance of either gecko species; it also did not have any apparent effects on resource partitioning between species. However, it did affect body size, dietary composition, and trophic position of both species. Geckos in subsidized, dicot forests were larger, had higher body condition and more diverse diets, and occupied a much higher trophic position than geckos found in palm dominated, low subsidy level forests. Both direct variation in subsidy levels and associated changes in habitat structure appear to play a role in driving these responses. These results suggest that variation in subsidy levels may drive important behavioral responses in predators, even when their numerical response is limited. Strong changes in trophic position of consumers also suggest that subsidies may drive increasingly complex food webs, with longer overall food chain length.

  4. Effects of spatial subsidies and habitat structure on the foraging ecology and size of geckos

    Science.gov (United States)

    Briggs, Amy A.; Young, Hillary S.; McCauley, Douglas J.; Hathaway, Stacie A.; Dirzo, Rodolfo; Fisher, Robert N.

    2012-01-01

    While it is well established that ecosystem subsidies—the addition of energy, nutrients, or materials across ecosystem boundaries—can affect consumer abundance, there is less information available on how subsidy levels may affect consumer diet, body condition, trophic position, and resource partitioning among consumer species. There is also little information on whether changes in vegetation structure commonly associated with spatial variation in subsidies may play an important role in driving consumer responses to subsidies. To address these knowledge gaps, we studied changes in abundance, diet, trophic position, size, and body condition of two congeneric gecko species (Lepidodactylus spp.) that coexist in palm dominated and native (hereafter dicot dominated) forests across the Central Pacific. These forests differ trongly both in the amount of marine subsidies that they receive from seabird guano and carcasses, and in the physical structure of the habitat. Contrary to other studies, we found that subsidy level had no impact on the abundance of either gecko species; it also did not have any apparent effects on resource partitioning between species. However, it did affect body size, dietary composition, and trophic position of both species. Geckos in subsidized, dicot forests were larger, had higher body condition and more diverse diets, and occupied a much higher trophic position than geckos found in palm dominated, low subsidy level forests. Both direct variation in subsidy levels and associated changes in habitat structure appear to play a role in driving these responses. These results suggest that variation in subsidy levels may drive important behavioral responses in predators, even when their numerical response is limited. Strong changes in trophic position of consumers also suggest that subsidies may drive increasingly complex food webs, with longer overall food chain length.

  5. Ecological effects of a long-term flood program in a flow-regulated river

    Directory of Open Access Journals (Sweden)

    Sabine Mannes

    2009-03-01

    Full Text Available Le régime hydrologique naturel de la grande majorité des rivières du globe a été modifié par une régulation artificielle, qui a profondément affecté la morphologie fluviale et la vie aquatique. L’intégration de critères hydrologiques comme le débit et la température dans les programmes de restauration constitue une étape importante pour la gestion de rivière. Cet article synthétise les observations, en terme de qualité physicochimique de l’eau et de biocénose aquatique, des effets d’une programmation de crues sur le long terme (15 crues artificielles en huit ans sur la rivière Spöl, dans le Parc National Suisse. Du fait des lâchers d’eau hypolimnétiques (issues des eaux profondes, ces crues ont peu d’impact sur les paramètres physiques et chimiques. La biomasse du périphyton a été réduite par les premières crues, puis s’est maintenue à des niveaux faibles pendant toute la période étudiée. La richesse spécifique, la biomasse et la densité de macro-invertébrés ont aussi été significativement réduites, et l’association de macroinvertébrés a évolué vers des taxons plus résistants aux perturbations. La qualité des habitats piscicoles, en particulier pour les zones de frai, a été sensiblement améliorée par les inondations. Une analyse plus approfondie a montré que la réponse de la biocénose à des crues d’ampleur similaire a changé pendant la période d’étude en parallèle avec la modification de la composition des associations biotiques.The natural flow regime of many rivers on the globe has been altered by regulation, strongly influencing river morphology and aquatic biota. The incorporation of regimebased criteria such as flow and temperature regimes in restoration plans is an important step in river management. This paper summarizes the effects of a long-term flood program (15 floods over 8 years on the river Spöl, Swiss National Park, on water physico-chemistry and river

  6. Effects of Supplementary Feeding on the Breeding Ecology of the Buff-Throated Partridge in a Tibetan Sacred Site, China.

    Science.gov (United States)

    Yang, Nan; Moermond, Timothy C; Lloyd, Huw; Xu, Yu; Dou, Liang; Zhang, Kai; Yue, Bisong; Ran, Jianghong

    2016-01-01

    Our goal was to document effects of year-round supplemental feeding on breeding ecology of the Buff-throated Partridge, Tetraophasis szechenyii, within a Tibetan sacred site. We evaluated effects of supplemental feeding used as religious/cultural practices which could potentially aid conservation of endangered phasianids. We compared fed breeding groups to neighboring nonfed groups. Fed groups initiated first clutches significantly earlier than nonfed groups. Earlier laying groups within fed and nonfed groups showed significantly lower hatching rates than later groups; however, fed groups showed significantly higher hatching rates than nonfed groups laying in the same period. Earlier laying increased opportunities to renest. All six fed groups with clutch failures renested compared to only one of five nonfed groups with clutch failures. Fed female breeders showed significantly greater investment in their young with larger clutches and larger eggs, which likely increased survivability of early hatchlings. We observed no predation on birds at feeding sites and recorded only four cases of predation on incubating females, which showed no detectable difference between fed and nonfed groups. Ground-nesting birds typically face high risks of predation. Ten of the 48 groups nested in trees, which occurs in few phasianid species. Tree nests showed significantly higher hatching rates compared to ground nests; however, we found no significant difference in tree nesting between fed and nonfed groups. This partridge is one of four gallinaceous species with cooperative breeding. Breeding groups with helpers had significantly greater reproductive success than single pairs, and fed female breeders with helpers laid bigger eggs than single pairs. Comparing annual reproductive output per group, fed groups not only produced significantly more independent young (≥ 150 days post-hatching), their young hatched significantly earlier, which likely have greater reproductive value over

  7. Short-term effects of the 2008 Great Recession on the health of the Italian population: an ecological study.

    Science.gov (United States)

    Mattei, Giorgio; Ferrari, Silvia; Pingani, Luca; Rigatelli, Marco

    2014-06-01

    To report on the effects on health that the 2008 Great Recession is producing in Italy, by comparing the consistency of Italian data with general observations reported in the scientific literature, and by pointing out consequences on the rates of all-cause mortality, cardiovascular mortality, male suicidal behaviours, daytime alcohol drinking and traffic fatalities. This is an ecological study in which MEDLINE, PsycINFO and PubMed were searched for the literature with combinations of the following keywords: economic recession, financial crisis, unemployment, health, suicide and mental health. Data from two Italian government agencies (Italian Institute of Statistics, ISTAT, and Italian Agency of Drugs, AIFA) in the years from 2000 to 2010 were obtained and analysed, by producing models of multiple linear regressions. After the recession onset, all-cause mortality remained stable, and was not associated with the economic fluctuations. Differently, cardiovascular mortality was associated with the rate of unemployment, and showed a significant increase in 2010. Alcohol consumption increased in 2009, the year with the worst real GDP decrease (-5.1 %). Though the total rate of suicide was not associated with the economic situation, male completed and attempted suicides due to financial crisis were significantly associated with the rate of unemployment and the real GDP. The increasing diffusion of antidepressants was not associated with a lowering of the rate of suicide. The data on the Italian situation here discussed are sufficiently reliable to conclude that a link exists between the ongoing economic recession and health and mental health of Italians. Further research is needed to understand more in detail and with stronger reliability such link, to support primary and secondary preventive interventions and orient the development of effective sociopolitical interventions.

  8. Ecological study of the effects of nuclear power plants on benthic macroplant microcosms in subtropical and tropical estuaries. Annual progress report, 1974--1975

    International Nuclear Information System (INIS)

    Thorhaug, A.

    1975-05-01

    Progress is reported on the following research projects: the dynamic ecology of Thalassia and studies of the Thalassia community; basic ecology of Thalassia growth and reproduction; red macroalgal ecology; green macroalgal ecology; transplantation of Thalassia; succession in a previously damaged Thalassia community at Turkey Point; and thermal ecology of the Thalassia community of Card Sound and Turkey Point. (U.S.)

  9. Ecological stability of landscape - ecological infrastructure - ecological management

    International Nuclear Information System (INIS)

    1992-01-01

    The Field Workshop 'Ecological Stability of Landscape - Ecological Infrastructure - Ecological Management' was held within a State Environmental Programme financed by the Federal Committee for the Environment. The objectives of the workshop were to present Czech and Slovak approaches to the ecological stability of the landscape by means of examples of some case studies in the field, and to exchange ideas, theoretical knowledge and practical experience on implementing the concept of ecological infrastructure in landscape management. Out of 19 papers contained in the proceedings, 3 items were inputted to the INIS system. (Z.S.)

  10. Ecological aspects of the nuclear age: selected readings in radiation ecology

    International Nuclear Information System (INIS)

    Schultz, V.; Whicker, F.W.

    1971-01-01

    A compilation of selected readings is presented in the areas of radiation ecology, radionuclide cycling, ionizing radiation effects, radioisotope tracer techniques in ecology, and military and peaceful uses of nuclear energy

  11. Fires, ecological effects of

    Science.gov (United States)

    W. J. Bond; Robert Keane

    2017-01-01

    Fire is both a natural and anthropogenic disturbance influencing the distribution, structure, and functioning of terrestrial ecosystems around the world. Many plants and animals depend on fire for their continued existence. Others species, such as rainforest plants species, are extremely intolerant of burning and need protection from fire. The properties of a fire...

  12. Individual and Interactive Effects of Socio-Ecological Factors on Dengue Fever at Fine Spatial Scale: A Geographical Detector-Based Analysis.

    Science.gov (United States)

    Cao, Zheng; Liu, Tao; Li, Xing; Wang, Jin; Lin, Hualiang; Chen, Lingling; Wu, Zhifeng; Ma, Wenjun

    2017-07-17

    Background : Large spatial heterogeneity was observed in the dengue fever outbreak in Guangzhou in 2014, however, the underlying reasons remain unknown. We examined whether socio-ecological factors affected the spatial distribution and their interactive effects. Methods : Moran's I was applied to first examine the spatial cluster of dengue fever in Guangzhou. Nine socio-ecological factors were chosen to represent the urbanization level, economy, accessibility, environment, and the weather of the 167 townships/streets in Guangzhou, and then the geographical detector was applied to analyze the individual and interactive effects of these factors on the dengue outbreak. Results : Four clusters of dengue fever were identified in Guangzhou in 2014, including one hot spot in the central area of Guangzhou and three cold spots in the suburban districts. For individual effects, the temperature ( q = 0.33) was the dominant factor of dengue fever, followed by precipitation ( q = 0.24), road density ( q = 0.24), and water body area ( q = 0.23). For the interactive effects, the combination of high precipitation, high temperature, and high road density might result in increased dengue fever incidence. Moreover, urban villages might be the dengue fever hot spots. Conclusions : Our study suggests that some socio-ecological factors might either separately or jointly influence the spatial distribution of dengue fever in Guangzhou.

  13. Ecological information on radiation hazards

    International Nuclear Information System (INIS)

    Matveev, V.V.; Stas', K.N.

    1992-01-01

    The accident at Chernobyl has affected health and has had economic consequences, and it has sharpened the call throughout the work for safety in industry, the supervision of technological processes, and monitoring effects on the environment. Safety and monitoring in the nuclear industry are being given a great deal of attention, and experience is being accumulated on methods of handling such tasks by virtue of the above and also because of features in nuclear processes and the plants based on them and the specific features of ionizing radiation and radioactive substances. The accident at Chernobyl showed that this apparently ill-encompassing monitoring was insufficient. One needs in essence a systematic approach to methods of obtaining, processing, and distributing information as well as organizational measures that together represent an ecological information system. This should be the basis on the one hand for an efficient system for safe operation of existing and developing industrial areas and for minimizing the adverse consequences of accidents, while on the other it should provide for understanding between social movements, specialists, and the population as regards particular ecological situations. To provide a clean environment and deal with pollution, one needs first of all reliable and prompt information on the states of natural and industrial areas, since without detailed evidence one cannot take any action and ensure a positive outcome. Such information is obtained with special equipment and monitoring systems. Monitoring implies the following: (1) measuring physical quantities or nuclide concentrations characterizing the physical fields, compositions, or states of objects or media; (2) interpreting the measurements and forecasting developments and effects

  14. Valuation of ecological resources

    Energy Technology Data Exchange (ETDEWEB)

    Scott, M.J.; Bilyard, G.R.; Link, S.O.; Ricci, P.F.; Seely, H.E.; Ulibarri, C.A.; Westerdahl, H.E.

    1995-04-01

    Ecological resources are resources that have functional value to ecosystems. Frequently, these functions are overlooked in terms of the value they provide to humans. Environmental economics is in search of an appropriate analysis framework for such resources. In such a framework, it is essential to distinguish between two related subsets of information: (1) ecological processes that have intrinsic value to natural ecosystems; and (2) ecological functions that are values by humans. The present study addresses these concerns by identifying a habitat that is being displaced by development, and by measuring the human and ecological values associated with the ecological resources in that habitat. It is also essential to determine which functions are mutually exclusive and which are, in effect, complementary or products of joint production. The authors apply several resource valuation tools, including contingent valuation methodology (CVM), travel cost methodology (TCM), and hedonic damage-pricing (HDP). One way to derive upper-limit values for more difficult-to-value functions is through the use of human analogs, because human-engineered systems are relatively inefficient at supplying the desired services when compared with natural systems. Where data on the relative efficiencies of natural systems and human analogs exist, it is possible to adjust the costs of providing the human analog by the relative efficiency of the natural system to obtain a more realistic value of the function under consideration. The authors demonstrate this approach in an environmental economic case study of the environmental services rendered by shrub-steppe habitats of Benton County, Washington State.

  15. Experimental terrestrial soil-core microcosm test protocol. A method for measuring the potential ecological effects, fate, and transport of chemicals in terrestrial ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Van Voris, P.; Tolle, D.A.; Arthur, M.F.

    1985-06-01

    In order to protect the environment properly and have a realistic appraisal of how a chemical will act in the environment, tests of ecological effects and chemical fate must be performed on complex assemblages of biotic and abiotic components (i.e., microcosms) as well as single species. This protocol is one which could be added to a series of tests recently developed as guidelines for Section 4 of the Toxic Substances Control Act (P.L. 94-469; U.S.C., Section 2601-2629). The terrestrial soil-core microcosm is designed to supply site-specific and possibly regional information on the probable chemical fate and ecological effects resulting from release of a chemical substance to a terrestrial ecosystem. The EPA will use the data resulting from this test system to compare the potential hazards of a chemical with others that have been previously evaluated.

  16. Evaluation of terrestrial microcosms for assessing the fate and effects of genetically engineered microorganisms on ecological processes

    Energy Technology Data Exchange (ETDEWEB)

    Fredrickson, J.K.; Bentjen, S.A.; Bolton, H. Jr.; Li, S.W.; Ligotke, M.W.; McFadden, K.M.; Van Voris, P.

    1989-04-01

    This project evaluates and modifies the existing US Environmental Protection Agency's Office of Pesticides and Toxic Substances (EPA/OPTS) terrestrial microcosm test system and test protocols such that they can be used to determine the environmental fate and ecological hazards of genetically engineered microorganisms (GEMs). The intact soil-core microcosm represents terrestrial ecosystems, and when coupled with appropriate test protocols, such microcosms may be appropriate to define and limit risks associated with the intentional release of GEMs. The terrestrial microcosm test system was used to investigate the survival and transport of two model GEMs (Azospirillum lipoferum and Pseudomonas sp. Tn5 mutants) to various trophic levels and niches and through intact soil cores. Subsequent effects on nutrient cycling and displacement of indigenous microorganisms were evaluated. The model organisms were a diazotrophic root-colonizing bacterium (A. lipoferum) and a wheat root growth-inhibiting rhizobacterium (Pseudomonas sp.). The transposable element Tn5 was used as a genetic marker for both microorganisms in two separate experiments. The organisms were subjected to transposon mutagenesis using a broad host-range-mobilizable suicide plasmid. The transposon Tn5 conferred levels of kanamycin resistance up to 500 ..mu..g/ml (Pseudomonas sp.), which allowed for selection of the bacteria from environmental samples. The presence of Tn5 DNA in the genome of the model GEMs also allowed the use of Tn5 gene probes to confirm and enumerate the microorganisms in different samples from the microcosms. Two types of root growth-inhibiting Pseudomonas sp. Tn5 mutants were obtained and used in microcosm studies: those that lacked the ability to inhibit either wheat root growth or the growth of other microorganisms in vitro (tox/sup /minus//) and those which retained these properties (tox/sup +/). 53 refs., 7 figs., 6 tabs.

  17. Effect of nationwide injury prevention programme on serious spinal injuries in New Zealand rugby union: ecological study.

    Science.gov (United States)

    Quarrie, Kenneth L; Gianotti, Simon M; Hopkins, Will G; Hume, Patria A

    2007-06-02

    To investigate the effect of RugbySmart, a nationwide educational injury prevention programme, on the frequency of spinal cord injuries. Ecological study. New Zealand rugby union. Population at risk of injury comprised all New Zealand rugby union players. From 2001, all New Zealand rugby coaches and referees have been required to complete RugbySmart, which focuses on educating rugby participants about physical conditioning, injury management, and safe techniques in the contact phases of rugby. Numbers of all spinal injuries due to participation in rugby union resulting in permanent disablement in 1976-2005, grouped into five year periods; observed compared with predicted number of spinal injuries in 2001-5. Eight spinal injuries occurred in 2001-5, whereas the predicted number was 18.9 (relative rate=0.46, 95% confidence interval 0.19 to 1.14). Only one spinal injury resulted from scrums over the period; the predicted number was 9.0 (relative rate=0.11, 0.02 to 0.74). Corresponding observed and predicted rates for spinal injuries resulting from other phases of play (tackle, ruck, and maul) were 7 and 9.0 (relative rate=0.83, 0.29 to 2.36). The introduction of the RugbySmart programme coincided with a reduction in the rate of disabling spinal injuries arising from scrums in rugby union. This study exemplifies the benefit of educational initiatives in injury prevention and the need for comprehensive injury surveillance systems for evaluating injury prevention initiatives in sport.

  18. Effects of food supplementation on the physiological ecology of female Western diamond-backed rattlesnakes (Crotalus atrox).

    Science.gov (United States)

    Taylor, Emily N; Malawy, Michael A; Browning, Dawn M; Lemar, Shea V; DeNardo, Dale F

    2005-06-01

    Food availability is an important factor in the life histories of organisms because it is often limiting and thus can affect growth, mass change, reproduction, and behaviors such as thermoregulation, locomotion, and mating. Experimental studies in natural settings allow researchers to examine the effects of food on these parameters while animals are free to behave naturally. The wide variation among organisms in energy demands and among environmental food resources suggest that responses to changes in food availability may vary among organisms. Since most supplemental feeding field experiments have been conducted on species with high energy demands, we conducted a supplemental feeding study on free-ranging, female Western diamond-backed rattlesnakes (Crotalus atrox), a species with low energy demands and infrequent reproductive investment. Snakes were offered thawed rodents 1-4 times per week. Over two active seasons, we collected data on surface activity, home range size, growth, mass change, and reproduction of supplementally fed and control snakes. Fed and control snakes did not differ in surface activity levels (proportion of time encountered above versus below ground) or home range size. Fed snakes grew and gained mass faster, and had a dramatically higher occurrence of reproduction than control snakes. Also, fed snakes were in better body condition following reproduction than snakes that were not fed. However, litter characteristics such as offspring number and size were not increased by feeding, suggesting that these characteristics may be fixed. These data experimentally demonstrate that food availability can directly impact some life history traits (i.e., growth and reproduction for C. atrox), but not others (i.e., surface activity and home range size for C. atrox). The relationship between food availability and life history traits is affected in a complex way by ecological traits and physiological constraints, and thus interspecific variation in this

  19. Ecological interface design for turbine secondary systems in a nuclear power plant : effects on operator situation awareness

    International Nuclear Information System (INIS)

    Kwok, J.

    2007-01-01

    Investigations into past accidents at nuclear power generating facilities such as that of Three Mile Island have identified human factors as one of the foremost critical aspects in plant safety. Errors resulting from limitations in human information processing are of particular concern for human-machine interfaces (HMI) in plant control rooms. This project examines the application of Ecological Interface Design (EID) in HMI information displays and the effects on operator situation awareness (SA) for turbine secondary systems based on the Swedish Forsmark 3 boiling-water reactor nuclear power plant. A work domain analysis was performed on the turbine secondary systems yielding part-whole decomposition and abstraction hierarchy models. Information display requirements were subsequently extracted from the models. The resulting EID information displays were implemented in a full-scope simulator and evaluated with six licensed operating crews from the Forsmark 3 plant. Three measures were used to examine SA: self-rated bias, Halden Open Probe Elicitation (HOPE), and Situation Awareness Control Room Inventory (SACRI). The data analysis revealed that operators achieved moderate to good SA; operators unfamiliar with EID information displays were able to develop and maintain comparable levels of SA to operators using traditional forms of single sensor-single indicator (SS-SI) information displays. With sufficient training and experience, operator SA is expected to benefit from the knowledge-based visual elements in the EID information displays. This project was researched in conjunction with the Cognitive Engineering Laboratory at the University of Toronto and the Institute for Energy Technology (IFE) in Halden, Norway. (author)

  20. Improving the effectiveness of ecological site descriptions: General state-and-transition models and the Ecosystem Dynamics Interpretive Tool (EDIT)

    Science.gov (United States)

    Bestelmeyer, Brandon T.; Williamson, Jeb C.; Talbot, Curtis J.; Cates, Greg W.; Duniway, Michael C.; Brown, Joel R.

    2016-01-01

    State-and-transition models (STMs) are useful tools for management, but they can be difficult to use and have limited content.STMs created for groups of related ecological sites could simplify and improve their utility. The amount of information linked to models can be increased using tables that communicate management interpretations and important within-group variability.We created a new web-based information system (the Ecosystem Dynamics Interpretive Tool) to house STMs, associated tabular information, and other ecological site data and descriptors.Fewer, more informative, better organized, and easily accessible STMs should increase the accessibility of science information.

  1. Indigenous Ecological Knowledge and Modern Western Ecological ...

    African Journals Online (AJOL)

    Indigenous knowledge is often dismissed as 'traditional and outdated', and hence irrelevant to modern ecological assessment. This theoretical paper critically examines the arguments advanced to elevate modern western ecological knowledge over indigenous ecological knowledge, as well as the sources and uses of ...

  2. A hyper-temporal remote sensing protocol for high-resolution mapping of ecological sites.

    Science.gov (United States)

    Maynard, Jonathan J; Karl, Jason W

    2017-01-01

    Ecological site classification has emerged as a highly effective land management framework, but its utility at a regional scale has been limited due to the spatial ambiguity of ecological site locations in the U.S. or the absence of ecological site maps in other regions of the world. In response to these shortcomings, this study evaluated the use of hyper-temporal remote sensing (i.e., hundreds of images) for high spatial resolution mapping of ecological sites. We posit that hyper-temporal remote sensing can provide novel insights into the spatial variability of ecological sites by quantifying the temporal response of land surface spectral properties. This temporal response provides a spectral 'fingerprint' of the soil-vegetation-climate relationship which is central to the concept of ecological sites. Consequently, the main objective of this study was to predict the spatial distribution of ecological sites in a semi-arid rangeland using a 28-year time series of normalized difference vegetation index from Landsat TM 5 data and modeled using support vector machine classification. Results from this study show that support vector machine classification using hyper-temporal remote sensing imagery was effective in modeling ecological site classes, with a 62% correct classification. These results were compared to Gridded Soil Survey Geographic database and expert delineated maps of ecological sites which had a 51 and 89% correct classification, respectively. An analysis of the effects of ecological state on ecological site misclassifications revealed that sites in degraded states (e.g., shrub-dominated/shrubland and bare/annuals) had a higher rate of misclassification due to their close spectral similarity with other ecological sites. This study identified three important factors that need to be addressed to improve future model predictions: 1) sampling designs need to fully represent the range of both within class (i.e., states) and between class (i.e., ecological sites

  3. International workshop 'Effect of ionizing radiation on ecological situation of countries from Caucasian region and Caspian sea basin'. Book of abstracts

    International Nuclear Information System (INIS)

    Kerimov, M.K.; Birsen, N.; Gaziev, A.I.

    2002-10-01

    The scientists from following countries took part at the international workshop: Azerbaijan, Turkey, Georgia, Kazakhstan, Russia, Uzbekistan. The activity was conducted in two sections. Section A was devoted to the problems of radiation safety and natural sciences of radiation contamination in Caucasian region and Caspian sea basin, oil industry and technology and environment monitoring. Section B was devoted to the evaluation of radiation risks, radioprotectors, ecological and genetical consequences of the anthropogenic factors effect on the environment

  4. Functional genetics of intraspecific ecological interactions in Arabidopsis thaliana.

    Science.gov (United States)

    Wolf, Jason B; Mutic, Joshua J; Kover, Paula X

    2011-05-12

    Studying the genetic basis of traits involved in ecological interactions is a fundamental part of elucidating the connections between evolutionary and ecological processes. Such knowledge allows one to link genetic models of trait evolution with ecological models describing interactions within and between species. Previous work has shown that connections between genetic and ecological processes in Arabidopsis thaliana may be mediated by the fact that quantitative trait loci (QTL) with 'direct' effects on traits of individuals also have pleiotropic 'indirect' effects on traits expressed in neighbouring plants. Here, we further explore these connections by examining functional relationships between traits affected directly and indirectly by the same QTL. We develop a novel approach using structural equation models (SEMs) to determine whether observed pleiotropic effects result from traits directly affected by the QTL in focal individuals causing the changes in the neighbours' phenotypes. This hypothesis was assessed using SEMs to test whether focal plant phenotypes appear to mediate the connection between the focal plants' genotypes and the phenotypes of their neighbours, or alternatively, whether the connection between the focal plants' genotypes and the neighbours' phenotypes is mediated by unmeasured traits. We implement this analysis using a QTL of major effect that maps to the well-characterized flowering locus, FRIGIDA. The SEMs support the hypothesis that the pleiotropic indirect effects of this locus arise from size and developmental timing-related traits in focal plants affecting the expression of developmental traits in their neighbours. Our findings provide empirical insights into the genetics and nature of intraspecific ecological interactions. Our technique holds promise in directing future work into the genetic basis and functional relationship of traits mediating and responding to ecological interactions.

  5. Mutualistic interactions drive ecological niche convergence in a diverse butterfly community.

    Science.gov (United States)

    Elias, Marianne; Gompert, Zachariah; Jiggins, Chris; Willmott, Keith

    2008-12-02

    Ecological communities are structured in part by evolutionary interactions among their members. A number of recent studies incorporating phylogenetics into community ecology have upheld the paradigm that competition drives ecological divergence among species of the same guild. However, the role of other interspecific interactions, in particular positive interactions such as mutualism, remains poorly explored. We characterized the ecological niche and inferred phylogenetic relationships among members of a diverse community of neotropical Müllerian mimetic butterflies. Müllerian mimicry is one of the best studied examples of mutualism, in which unpalatable species converge in wing pattern locally to advertize their toxicity to predators. We provide evidence that mutualistic interactions can drive convergence along multiple ecological axes, outweighing both phylogeny and competition in shaping community structure. Our findings imply that ecological communities are adaptively assembled to a much greater degree than commonly suspected. In addition, our results show that phenotype and ecology are strongly linked and support the idea that mimicry can cause ecological speciation through multiple cascading effects on species' biology.

  6. Mutualistic interactions drive ecological niche convergence in a diverse butterfly community.

    Directory of Open Access Journals (Sweden)

    Marianne Elias

    2008-12-01

    Full Text Available Ecological communities are structured in part by evolutionary interactions among their members. A number of recent studies incorporating phylogenetics into community ecology have upheld the paradigm that competition drives ecological divergence among species of the same guild. However, the role of other interspecific interactions, in particular positive interactions such as mutualism, remains poorly explored. We characterized the ecological niche and inferred phylogenetic relationships among members of a diverse community of neotropical Müllerian mimetic butterflies. Müllerian mimicry is one of the best studied examples of mutualism, in which unpalatable species converge in wing pattern locally to advertize their toxicity to predators. We provide evidence that mutualistic interactions can drive convergence along multiple ecological axes, outweighing both phylogeny and competition in shaping community structure. Our findings imply that ecological communities are adaptively assembled to a much greater degree than commonly suspected. In addition, our results show that phenotype and ecology are strongly linked and support the idea that mimicry can cause ecological speciation through multiple cascading effects on species' biology.

  7. Using ecological theory to evaluate the effectiveness of an indigenous community intervention: A study of Sexual Assault Nurse Examiner (SANE) programs.

    Science.gov (United States)

    Campbell, Rebecca; Patterson, Debra; Fehler-Cabral, Giannina

    2010-12-01

    In recent years, there has been renewed interest among community psychologists in indigenous interventions, which are programs created by local practitioners (rather than researchers) already rooted in their communities. Indigenous interventions have strong ecological validity, but their effectiveness is often unknown because so few are rigorously evaluated. The goal of this project was to use Kelly and Trickett's ecological theory as a conceptual framework for evaluating an indigenous intervention and its mediating mechanisms of effectiveness. The focal intervention was a midwestern Sexual Assault Nurse Examiner (SANE) program, which provides post-assault medical care, crisis intervention, and medical forensic exams for sexual assault survivors. Prior studies of SANE programs have suggested that these interventions may help increase sexual assault prosecution rates. In this case example, we used a mixed methods design to determine if this program contributed to increased prosecution rates, and if so, why. Based on qualitative interviews with key stakeholders, we found substantial evidence for the Principle of Interdependence such that the SANE program strengthened the interconnections between the legal and medical systems, which contributed to increased prosecution. The intervention was effective in these outcomes because it promoted Cycling of Resources throughout the systems and fostered Adaptation of new roles for legal and medical personnel. Moving beyond this specific case example, this paper also examines cross-cutting advantages and struggles of using an ecological approach in the evaluation of indigenous community interventions.

  8. Ecological characterization of two species of exotic fish, pumpkinseed sunfish (Lepomis gibbosus and largemouth bass (Micropterus salmoides in the international Minho river

    Directory of Open Access Journals (Sweden)

    Ana Cristina Lages

    2015-11-01

    Full Text Available The introduction of exotic species is considered the main cause for the decline of native species. The largemouth bass (Micropterus salmoides and pumpkinseed sunfish (Lepomis gibbosus are two native species from North America, introduced in Portugal to enhance sport fishing. However, their diet and great adaptability made them considered predatory and harmful. In order to understand the ecological impact of M. salmoides and L. gibbosus in the international section of the Minho River, three sampling sites were selected: two in Vila Nova de Cerveira and one in Lapela, at distance of the mouth of the river of 17 and 45 Km, respectively. The fish were gathered using fyke nets and trammel nets, electric fishing and fishing rod, with performed samplings since July 2014 until October 2015. For all fish caught the biometric data (weight, total and fork length, gonad and liver weight, sex, stomach contents analysis were registered as well as collection of otoliths and scales for age reading. Both species feed on small macroinvertebrates specially the juveniles while adults of largemouth bass and pumpkinseed sunfish prefer eat fish and gastropods, respectively. Because L. gibbosus is a recent introduction in the Minho river estuary its abundance increased a lot in the last two years and it was possible verify the increase of the fish population average length. With this work it is intended to evaluate the impact in the Minho River estuary of both exotic species studying the population structure, trophic webs and reproduction.

  9. Using MPAs to address regional-scale ecological objectives in the North Sea: modelling the effects of fishing effort displacement

    NARCIS (Netherlands)

    Greenstreet, S.P.R.; Fraser, H.M.; Piet, G.J.

    2009-01-01

    The use of Marine Protected Areas (MPAs) to address regional-scale objectives as part of an ecosystem approach to management in the North Sea is examined. Ensuring that displacement of fishing activity does not negate the ecological benefits gained from MPAs is a major concern. Two scenarios are

  10. Ecological effects of alternative fuel-reduction treatments: highlights of the National Fire and Fire Surrogate study (FFS)

    Science.gov (United States)

    James D. McIver; Scott L. Stephens; James K. Agee; Jamie Barbour; Ralph E. J. Boerner; Carl B. Edminster; Karen L. Erickson; Kerry L. Farris; Christopher J. Fettig; Carl E. Fiedler; Sally Haase; Stephen C. Hart; Jon E. Keeley; Eric E. Knapp; John F. Lehmkuhl; Jason J. Moghaddas; William Otrosina; Kenneth W. Outcalt; Dylan W. Schwilk; Carl N. Skinner; Thomas A. Waldrop; C. Phillip Weatherspoon; Daniel A. Yaussy; Andrew Youngblood; Steve Zack

    2012-01-01

    The 12-site National Fire and Fire Surrogate study (FFS) was a multivariate experiment that evaluated ecological consequences of alternative fuel-reduction treatments in seasonally dry forests of the US. Each site was a replicated experiment with a common design that compared an un-manipulated control, prescribed fire, mechanical and mechanical + fire treatments....

  11. Ecological weed management by cover cropping : effects on weed growth in autumn and weed establishment in spring

    NARCIS (Netherlands)

    Kruidhof, H.M.; Bastiaans, L.; Kropff, M.J.

    2008-01-01

    Cover crops grown in the period between two main crops have potential as an important component of a system-oriented ecological weed management strategy. In late summer and autumn, the cover crop can suppress growth and seed production of weeds, whereas the incorporation of cover crop residues in

  12. The Effect of Recycling Education on High School Students' Conceptual Understanding about Ecology: A Study on Matter Cycle

    Science.gov (United States)

    Ugulu, Ilker; Yorek, Nurettin; Baslar, Suleyman

    2015-01-01

    The objective of this study is to analyze and determine whether a developed recycling education program would lead to a positive change in the conceptual understanding of ecological concepts associated with matter cycles by high school students. The research was conducted on 68 high school 10th grade students (47 female and 21 male students). The…

  13. Multi-Target Risk Assessment of Potentially Toxic Elements in Farmland Soil Based on the Environment-Ecological-Health Effect.

    Science.gov (United States)

    Wang, Zhongyang; Meng, Bo; Zhang, Wei; Bai, Jinheng; Ma, Yingxin; Liu, Mingda

    2018-05-28

    There are potential impacts of Potentially Toxic Elements (PTEs) (e.g., Cd, Cr, Ni, Cu, As, Zn, Hg, and Pb) in soil from the perspective of the ecological environment and human health, and assessing the pollution and risk level of soil will play an important role in formulating policies for soil pollution control. Lingyuan, in the west of Liaoning Province, China, is a typical low-relief terrain of a hilly area. The object of study in this research is the topsoil of farmland in this area, of which 71 soil samples are collected. In this study, research methods, such as the Nemerow Index, Potential Ecological Hazard Index, Ecological Risk Quotient, Environmental Exposure Hazard Analysis, Positive Matrix Factorization Model, and Land Statistical Analysis, are used for systematical assessment of the pollution scale, pollution level, and source of PTEs, as well as the ecological environmental risks and health risks in the study area. The main conclusions are: The average contents of As, Cd, Cr, Cu, Hg, Zn, Ni, and Pb of the soil are 5.32 mg/kg, 0.31 mg/kg, 50.44 mg/kg, 47.05 mg/kg, 0.03 mg/kg, 79.36 mg/kg, 26.01 mg/kg, and 35.65 mg/kg, respectively. The contents of Cd, Cu, Zn, and Pb exceed the background value of local soil; Cd content of some study plots exceeds the National Soil Environmental Quality Standard Value (0.6 mg/kg), and the exceeding standard rate of study plots is 5.63%; the comprehensive potential ecological hazard assessment in the study area indicates that the PTEs are at a slight ecological risk; probabilistic hazard quotient assessment indicates that the influence of PTEs on species caused by Cu is at a slight level ( p = 10.93%), and Zn, Pb, and Cd are at an acceptable level. For the ecological process, Zn is at a medium level ( p = 25.78%), Cu is at a slight level (19.77%), and the influence of Cd and Pb are acceptable; human health hazard assessment states that the Non-carcinogenic comprehensive health hazard index HI = 0.16 natural source are 13

  14. Use of ecological exposure units in ecological risk assessment

    International Nuclear Information System (INIS)

    Ferenbaugh, R.; Myers, O.; Gallegos, A.; Breshears, D.; Ebinger, M.

    1995-01-01

    The traditional approach to ecological risk assessment at hazardous waste sites that are being evaluated for cleanup under CERCLA or RCRA requirements is to focus on the immediate impacts at or adjacent to a site. While this may be acceptable in some situations, it is not ecologically defensible in situations where there are numerous contaminated sites in proximity to each other. In the latter case, transport from the sites, potential cumulative effects, and wide-ranging receptors must be considered. The concept of the Ecological Exposure Unit (EEU) has been proposed to address this situation. Ecological Exposure Units are defined on the basis of ecological considerations and each EEU may contain several to many contaminated sites. The initial steps involved in performing ecological risk assessments using the EEU approach include (1) selection of appropriate receptors and assessment endpoints, and (2) geographical definition of EEUs. At Los Alamos National Laboratory, receptors have been identified and EEUs have been defined for these receptors. GIS is being used as a tool to map EEUs. Receptors include representatives from threatened or endangered species, species reflecting status of ecological health, species with social or cultural relevance, and other species of concern. After definition of EEUs, cumulative impacts of all stressors at all sites within each EEU must be evaluated. The two major advantages to performing ecological risk assessments using this approach are that risk assessments are performed in a more scientifically defensible manner because they are performed on ecologically defined units and that resources are used optimally by minimizing redundant remedial activities

  15. Temporal ecology in the Anthropocene.

    Science.gov (United States)

    Wolkovich, E M; Cook, B I; McLauchlan, K K; Davies, T J

    2014-11-01

    Two fundamental axes - space and time - shape ecological systems. Over the last 30 years spatial ecology has developed as an integrative, multidisciplinary science that has improved our understanding of the ecological consequences of habitat fragmentation and loss. We argue that accelerating climate change - the effective manipulation of time by humans - has generated a current need to build an equivalent framework for temporal ecology. Climate change has at once pressed ecologists to understand and predict ecological dynamics in non-stationary environments, while also challenged fundamental assumptions of many concepts, models and approaches. However, similarities between space and time, especially related issues of scaling, provide an outline for improving ecological models and forecasting of temporal dynamics, while the unique attributes of time, particularly its emphasis on events and its singular direction, highlight where new approaches are needed. We emphasise how a renewed, interdisciplinary focus on time would coalesce related concepts, help develop new theories and methods and guide further data collection. The next challenge will be to unite predictive frameworks from spatial and temporal ecology to build robust forecasts of when and where environmental change will pose the largest threats to species and ecosystems, as well as identifying the best opportunities for conservation. © 2014 John Wiley & Sons Ltd/CNRS.

  16. Preparation, characterization and catalytic effects of copper oxalate nanocrystals

    International Nuclear Information System (INIS)

    Singh, Gurdip; Kapoor, Inder Pal Singh; Dubey, Reena; Srivastava, Pratibha

    2012-01-01

    Graphical abstract: Prepared copper oxalate nanocrystals were characterized by FE-SEM and bright field TEM micrographs. Its catalytic activity was evaluated on the thermal decomposition of ammonium perchlorate using TG and TG-DSC techniques. Highlights: ► Preparation of nanocrystals (∼9.0 nm) of copper oxalate using Cu(NO 3 ) 2 ·2H 2 O, oxalic acid and acetone under thermal conditions. ► Method is simple and novel. ► Characterization using XRD, SEM, TEM, HRTEM and ED pattern. ► Catalytic activity of copper oxalate nanocrystals on AP thermal decomposition using thermal techniques (TG, TG-DSC and ignition delay). ► Kinetics of thermal decomposition of AP + CONs using isoconversional and model fitting kinetic approaches. - Abstract: Recent work has described the preparation and characterization of copper oxalate nanocrystals (CONs). It was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and electron diffraction pattern (ED). The catalytic activity of CONs on the thermal decomposition of ammonium perchlorate (AP) and composite solid propellants (CSPs) has been done by thermogravimetry (TG), differential scanning calorimetry (DSC) and ignition delay measurements. Burning rate of CSPs was also found to be enhanced in presence of copper oxalate nanocrystals. Kinetics of thermal decomposition of AP with and without CONs has also been investigated. The model free (isoconversional) and model-fitting kinetic approaches have been applied to data for isothermal TG decomposition.

  17. A Systems-Level Approach to Characterizing Effects of ENMs ...

    Science.gov (United States)

    Engineered nanomaterials (ENMs) represent a new regulatory challenge because of their unique properties and their potential to interact with ecological organisms at various developmental stages, in numerous environmental compartments. Traditional toxicity tests have proven to be unreliable due to their short-term nature and the subtle responses often observed following ENM exposure. In order to fully assess the potential for various ENMs to affect responses in organisms and ecosystems, we are using a systems-level framework to link molecular initiating events with changes in whole-organism responses, and to identify how these changes may translate across scales to disrupt important ecosystem processes. This framework utilizes information from nanoparticle characteristics and exposures to help make linkages across scales. We have used Arabidopsis thaliana as a model organism to identify potential transcriptome changes in response to specific ENMs. In addition, we have focused on plant species of agronomic importance to follow multi-generational changes in physiology and phenology, as well as epigenetic markers to identify possible mechanisms of inheritance. We are employing and developing complementary analytical tools (plasma-based and synchrotron spectroscopies, microscopy, and molecular and stable-isotopic techniques) to follow movement of ENMs and ENM products in plants as they develop. These studies have revealed that changes in gene expression do not a

  18. Implementation-effectiveness trial of an ecological intervention for physical activity in ethnically diverse low income senior centers

    Directory of Open Access Journals (Sweden)

    Porchia Rich

    2017-07-01

    Full Text Available Abstract Background As the US population ages, there is an increasing need for evidence based, peer-led physical activity programs, particularly in ethnically diverse, low income senior centers where access is limited. Methods/design The Peer Empowerment Program 4 Physical Activity’ (PEP4PA is a hybrid Type II implementation-effectiveness trial that is a peer-led physical activity (PA intervention based on the ecological model of behavior change. The initial phase is a cluster randomized control trial randomized to either a peer-led PA intervention or usual center programming. After 18 months, the intervention sites are further randomized to continued support or no support for another 6 months. This study will be conducted at twelve senior centers in San Diego County in low income, diverse communities. In the intervention sites, 24 peer health coaches and 408 adults, aged 50 years and older, are invited to participate. Peer health coaches receive training and support and utilize a tablet computer for delivery and tracking. There are several levels of intervention. Individual components include pedometers, step goals, counseling, and feedback charts. Interpersonal components include group walks, group sharing and health tips, and monthly celebrations. Community components include review of PA resources, walkability audit, sustainability plan, and streetscape improvements. The primary outcome of interest is intensity and location of PA minutes per day, measured every 6 months by wrist and hip accelerometers and GPS devices. Secondary outcomes include blood pressure, physical, cognitive, and emotional functioning. Implementation measures include appropriateness & acceptability (perceived and actual fit, adoption & penetration (reach, fidelity (quantity & quality of intervention delivered, acceptability (satisfaction, costs, and sustainability. Discussion Using a peer led implementation strategy to deliver a multi-level community based PA

  19. Novel Polyfermentor intestinal model (PolyFermS for controlled ecological studies: validation and effect of pH.

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    Annina Zihler Berner

    Full Text Available In vitro gut fermentation modeling offers a useful platform for ecological studies of the intestinal microbiota. In this study we describe a novel Polyfermentor Intestinal Model (PolyFermS designed to compare the effects of different treatments on the same complex gut microbiota. The model operated in conditions of the proximal colon is composed of a first reactor containing fecal microbiota immobilized in gel beads, and used to continuously inoculate a set of parallel second-stage reactors. The PolyFermS model was validated with three independent intestinal fermentations conducted for 38 days with immobilized human fecal microbiota obtained from three child donors. The microbial diversity of reactor effluents was compared to donor feces using the HITChip, a high-density phylogenetic microarray targeting small subunit rRNA sequences of over 1100 phylotypes of the human gastrointestinal tract. Furthermore, the metabolic response to a decrease of pH from 5.7 to 5.5, applied to balance the high fermentative activity in inoculum reactors, was studied. We observed a reproducible development of stable intestinal communities representing major taxonomic bacterial groups at ratios similar to these in feces of healthy donors, a high similarity of microbiota composition produced in second-stage reactors within a model, and a high time stability of microbiota composition and metabolic activity over 38 day culture. For all tested models, the pH-drop of 0.2 units in inoculum reactors enhanced butyrate production at the expense of acetate, but was accompanied by a donor-specific reorganization of the reactor community, suggesting a concerted metabolic adaptation and trigger of community-specific lactate or acetate cross-feeding pathways in response to varying pH. Our data showed that the PolyFermS model allows the stable cultivation of complex intestinal microbiota akin to the fecal donor and can be developed for the direct comparison of different

  20. Characterization uncertainty and its effects on models and performance

    International Nuclear Information System (INIS)

    Rautman, C.A.; Treadway, A.H.

    1991-01-01

    Geostatistical simulation is being used to develop multiple geologic models of rock properties at the proposed Yucca Mountain repository site. Because each replicate model contains the same known information, and is thus essentially indistinguishable statistically from others, the differences between models may be thought of as representing the uncertainty in the site description. The variability among performance measures, such as ground water travel time, calculated using these replicate models therefore quantifies the uncertainty in performance that arises from uncertainty in site characterization

  1. Terrestrial Ecology Section

    International Nuclear Information System (INIS)

    Harris, W.F.

    1978-01-01

    Studies on ecological effects of coal combustion included the following: episodic air pollution stress; interaction of gaseous pollutants and acid precipitation; and brimstone: preliminary results from SO 2 effects on forest growth. Studies on fate and transport of contaminants included deposition of aerosol-associated trace elements to a deciduous forest; hydrologic source areas; and environmental behavior of mercury. The environmental research park is described and forest resource management is discussed. Ecosystem analysis studies included hydrology of Walker branch; water budget of an oak-hickory forest; nutrient release from decaying wood; transpiration of the tulip poplar; and atmospheric CO 2 and its interaction with biospheric changes

  2. Squamation and ecology of thelodonts.

    Directory of Open Access Journals (Sweden)

    Humberto G Ferrón

    Full Text Available Thelodonts are an enigmatic group of Paleozoic jawless vertebrates that have been well studied from taxonomical, biostratigraphic and paleogeographic points of view, although our knowledge of their ecology and mode of life is still scant. Their bodies were covered by micrometric scales whose morphology, histology and the developmental process are extremely similar to those of extant sharks. Based on these similarities and on the well-recognized relationship between squamation and ecology in sharks, here we explore the ecological diversity and lifestyles of thelodonts. For this we use classic morphometrics and discriminant analysis to characterize the squamation patterns of a significant number of extant shark species whose ecology is well known. Multivariate analyses have defined a characteristic squamation pattern for each ecological group, thus establishing a comparative framework for inferring lifestyles in thelodonts. We then use this information to study the squamation of the currently described 147 species of thelodonts, known from both articulated and disarticulated remains. Discriminant analysis has allowed recognizing squamation patterns comparable to those of sharks and links them to specific ecological groups. Our results suggest a remarkable ecological diversity in thelodonts. A large number of them were probably demersal species inhabiting hard substrates, within caves and crevices in rocky environments or reefs, taking advantage of the flexibility provided by their micromeric squamations. Contrary to classical interpretations, only few thelodonts were placed among demersal species inhabiting sandy and muddy substrates. Schooling species with defensive scales against ectoparasites could be also abundant suggesting that social interactions and pressure of ectoparasites were present in vertebrates as early the Silurian. The presence of species showing scales suggestive of low to moderate speed and a lifestyle presumably associated

  3. Ecological niche of plant pathogens

    Directory of Open Access Journals (Sweden)

    Ecaterina Fodor

    2011-06-01

    Full Text Available Disease ecology is a new approach to the understanding of the spread and dynamics of pathogens in natural and man-made environments. Defining and describing the ecological niche of the pathogens is one of the major tasks for ecological theory, as well as for practitioners preoccupied with the control and forecasting of established and emerging diseases. Niche theory has been periodically revised, not including in an explicit way the pathogens. However, many progresses have been achieved in niche modeling of disease spread, but few attempts were made to construct a theoretical frame for the ecological niche of pathogens. The paper is a review of the knowledge accumulated during last decades in the niche theory of pathogens and proposes an ecological approach in research. It quest for new control methods in what concerns forest plant pathogens, with a special emphasis on fungi like organisms of the genus Ph