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Notes on survey-based spatial indicators for monitoring fish populations
2009
Woillez, Mathieu | Rivoirard, Jacques | Petitgas, Pierre
This paper presents the spatial indicators used in the European project FISBOAT. These are statistics intended to capture spatial patterns of fish populations, using fish density data collected during scientific surveys. To handle diffuse population limits, indicators are designed not to depend on arbitrary delineation of the domain. They characterize the location (centre of gravity and spatial patches), occupation of space (inertia, isotropy, positive area, spreading area and equivalent area) and microstructure. Collocation between different populations is summarized by a global index of collocation. These spatial indicators have the potential to be used in a monitoring system to detect changes in spatial distribution. They could be helpful for relating the spatial distribution properties of fish stocks to their dynamics, their habitats, or to climate change.
اظهر المزيد [+] اقل [-]Soil sampling based on field spatial variability of soil microbial indicators
2009
Peigné, Joséphine | Vian, Jean-François | Cannavacciuolo, Mario | Bottollier, B. | Chaussod, Rémi | Institut supérieur d'agriculture et d'agroalimentaire Rhône-Alpes (I.S.A.R.A.) | Ecole Supérieure d'Agriculture (Groupe ESA) | Microbiologie ; Institut National de la Recherche Agronomique (INRA)-Université de Bourgogne (UB)
International audience | Microbial indicators exhibit a high spatial heterogeneity which often masks comparison of the effects of different soil management treatments. It is therefore desirable to use a proper sampling design which integrates spatial heterogeneity at field level. Thus, the objectives were: (1) to study the spatial heterogeneity of biological and chemical soil variables, and (2) with obtained maps of spatial variability to test different sampling strategies to assess the usefulness of this ‘new’ soil map unit. 63 soil samples were collected according to a 10 m × 10 m grid on a 0.48 ha plot. On each of these samples, 10 variables were measured: soil water content, cation exchange capacity (CEC), organic carbon (OC) and total nitrogen (N), C/N, soil microbial biomass (SMB), labile soil organic matter (LOM), mineralisable C (Cmin) and N (Nmin), inverse of specific respiratory activity (1/SRA = SBM/Cmin). The spatial heterogeneity of each variable was charted with geostatistics. The biological variables exhibited spatial variability of the same order of magnitude as physicochemical parameters. From the maps, zones with different levels of organic matter, microbial biomass and specific respiratory activity were identified. The spatial patterns of SMB and SRA were related to CEC (positively for SMB and negatively for SRA), pointing out the effects of soil protection on microbial biomass and availability of organic substrates. The definition of these zones for a pool of variables (OC, N, SMB, LOM, CEC) is useful at 3 levels: (1) to record the initial values of the measured variables for each plot, (2) to integrate these zones as blocks in experimental design for future experiments, and (3) to focus analysis of specific biological mechanisms such as activity of micro-organisms.
اظهر المزيد [+] اقل [-]Assessment Tools for Urban Catchments: Developing Biological Indicators Based on Benthic Macroinvertebrates
2009
Purcell, Alison H. | Bressler, David W. | Paul, Michael J. | Barbour, Michael T. | Rankin, Ed T. | Carter, James L. | Resh, Vincent H.
Biological indicators, particularly benthic macroinvertebrates, are widely used and effective measures of the impact of urbanization on stream ecosystems. A multimetric biological index of urbanization was developed using a large benthic macroinvertebrate dataset (n = 1,835) from the Baltimore, Maryland, metropolitan area and then validated with datasets from Cleveland, Ohio (n = 79); San Jose, California (n = 85); and a different subset of the Baltimore data (n = 85). The biological metrics used to develop the multimetric index were selected using several criteria and were required to represent ecological attributes of macroinvertebrate assemblages including taxonomic composition and richness (number of taxa in the insect orders of Ephemeroptera, Plecoptera, and Trichoptera), functional feeding group (number of taxa designated as filterers), and habit (percent of individuals which cling to the substrate). Quantile regression was used to select metrics and characterize the relationship between the final biological index and an urban gradient (composed of population density, road density, and urban land use). Although more complex biological indices exist, this simplified multimetric index showed a consistent relationship between biological indicators and urban conditions (as measured by quantile regression) in three climatic regions of the United States and can serve as an assessment tool for environmental managers to prioritize urban stream sites for restoration and protection.
اظهر المزيد [+] اقل [-]Indices based on surface indicators predict soil functioning in Mediterranean semi-arid steppes
2009
Maestre, Fernando T. | Puche, María D.
Methodologies based on indicators occupy a prevalent place when assessing ecosystem functioning and monitoring desertification processes because they are affordable yet do not compromise accuracy. The landscape function analysis (LFA), developed in Australia by David Tongway (CSIRO), uses soil surface indicators to assess the condition of a given ecosystem by producing three numerical indices (stability, infiltration and nutrient cycling) reflecting the status of basic soil functions. None of the previous studies aiming to validate the LFA indices have explored how they relate to surrogates of soil functioning using a large number of test sites capturing different climatic and soil conditions. We aimed to do so using data gathered in 29 Stipa tenacissima steppes in Spain. The nutrient cycling index was strongly correlated with soil variables related to microbial activity and nutrient cycling, such as soil pH, total soil N and P, soil respiration and phosphatase and β-glucosidase activities. Strong correlations between the infiltration index and both soil compaction and the water holding capacity of soils were found. The stability index was also significantly correlated with most of the soil variables evaluated. These relationships were evident in both gypsum and calcareous soils. Our results indicate that the LFA indices may be employed as surrogates of soil variables related to nutrient cycling and water infiltration in semi-arid S. tenacissima steppes. The LFA methodology has an enormous potential to assist land managers and policy makers in the establishment of cost-effective desertification monitoring and restoration programs in semi-arid environments.
اظهر المزيد [+] اقل [-]Developing fish community based ecohydrological indicators for water resources management in Taiwan
2009
Suen, Jian-Ping | Herricks, Edwin E.
With concerns about the maintenance of both aquatic communities and flow conditions, a number of hydrologic indicators have been developed. These indicators are generally based on the development of hydrologic statistics for flows that are important to the maintenance of aquatic ecosystems. Although the hydrologic basis for indicators is well defined by common techniques in stochastic hydrology, the basis for ecological integration is still being developed. A critical evaluation of hydrologic indicators intended to protect aquatic ecosystems finds that proposed indicators are based more on standard hydrologic statistics and measures of hydrologic alteration than the habitat needs and ecological requirements of local or desired aquatic communities. We argue that hydrologic indicators are not ecohydrological indicators unless direct connections between flow events and aquatic community habitat and ecological needs are the basis of the indicator development and selection. In this article, we identify ecohydrological indicators that are based on habitat and ecological needs of fish communities. The indicator identification process is initiated with the analysis of community needs using an autecology matrix. Hydrologic statistics are then selected that are appropriate to the target fish community. The resulting ecohydrological indicators provide a direct connection to fish community flow requirements and the physical habitat conditions and associated ecology and life history needs of fish species.
اظهر المزيد [+] اقل [-]A Exploratory Study of Performance Indicators for Corporate Education Based on Performance Management Theory
2009
Hwang, S.J., POSCO, Pohang, Republic of Korea | Kim, J.M., Seoul National University, Seoul, Republic of Korea
The purpose of this study was to explore performance indicators for corporate education based on performance management theory. Because corporate performance management is primarily focusing on achieving strategic goals of the organization, performance indicators for corporate education associated strategic goals should be developed to monitor the implementation process and measure performance. Therefore, organization for corporate education needs strategic corporate education process, and take advantage of metrics approach to use objective and comparable measures. Typical advanced performance indicators by metrics approach are ASTD metrics, human resource metrics, metrics for learning and growth perspective in BSC, and metrics in survey on korea HRD. If corporate education organization uses those metrics, trial and error to develop indicator can be minimized. To set up performance indicators available to corporate education, the performance indicators are classified as two types, which are effectiveness indicators related to achieving strategic goals and efficiency indicators related to output compared to input. Effectiveness indicators are presented by analysis of the result of previous studies in 5 areas such as improving employee competencies, leadership and development of talent, sharing organizational culture, organizational learning and knowledge sharing, and improving business performance. Meanwhile efficiency indicators are presented by analysis of the result of previous studies according to 5 areas such as educational investment, educational staff, curriculum, forms and methods of education, and evaluation for education.
اظهر المزيد [+] اقل [-]Comparison of methods to assess the sustainability of agricultural systems. A review
2009
Bockstaller, Christian | Guichard, Laurence | Keichinger, Olivier | Girardin, Philippe | Galan, Marie-Béatrice | Gaillard, Gérard
Since the 1990s, numerous agri-environmental indicators and indicator-based methods have been developed to assess the adverse effects of cropping and farming systems such as water pollution by nitrates and pesticides, and gaseous emissions due to nitrogen inputs. This wealth of environmental indicators and assessment methods based on indicators raises issues on the quality of the methods and of the indicators, and on the relevancy of results. Evaluation and comparative studies are therefore needed to answer such issues. Here, we present four recent comparative studies selected for their illustrative value, first, to analyse the methodologies used for comparison of methods, and second, to highlight the main results of the four comparisons. The first study involves 23 indicators to address nitrate leaching. The second study involves 43 indicators to address pesticide risk. The third and fourth studies compare environmental assessment methods based on 4–5 indicators used in French and Upper Rhine plains (France, Germany and Switzerland). Both studies also compare the outputs of the methods and highlight the low degree of convergence between them. The approach proposed in the last study is the most elaborate among the four case studies. It could be used to develop a generic evaluation and comparison methodology. The review of those four case studies shows the need to formalise the methodology underlying any comparison work of indicators or evaluation methods.
اظهر المزيد [+] اقل [-]Comparison of methods to assess the sustainability of agricultural systems. A review
2009
Bockstaller, Christian | Guichard, Laurence | Keichinger, Olivier | Girardin, Philippe | Galan, Marie-Béatrice | Gaillard, Gérard
Since the 1990s, numerous agri-environmental indicators and indicator-based methods have been developed to assess the adverse effects of cropping and farming systems such as water pollution by nitrates and pesticides, and gaseous emissions due to nitrogen inputs. This wealth of environmental indicators and assessment methods based on indicators raises issues on the quality of the methods and of the indicators, and on the relevancy of results. Evaluation and comparative studies are therefore needed to answer such issues. Here, we present four recent comparative studies selected for their illustrative value, first, to analyse the methodologies used for comparison of methods, and second, to highlight the main results of the four comparisons. The first study involves 23 indicators to address nitrate leaching. The second study involves 43 indicators to address pesticide risk. The third and fourth studies compare environmental assessment methods based on 4–5 indicators used in French and Upper Rhine plains (France, Germany and Switzerland). Both studies also compare the outputs of the methods and highlight the low degree of convergence between them. The approach proposed in the last study is the most elaborate among the four case studies. It could be used to develop a generic evaluation and comparison methodology. The review of those four case studies shows the need to formalise the methodology underlying any comparison work of indicators or evaluation methods.
اظهر المزيد [+] اقل [-]Comparison of methods to assess the sustainability of agricultural systems. A review
2009
Bockstaller, Christian | Guichard, Laurence | Keichinger, Olivier | Girardin, Philippe | Galan, Marie-Beatrice | Gaillard, Gerard
Since the 1990s, numerous agri-environmental indicators and indicator-based methods have been developed to assess the adverse effects of cropping and farming systems such as water pollution by nitrates and pesticides, and gaseous emissions due to nitrogen inputs. This wealth of environmental indicators and assessment methods based on indicators raises issues on the quality of the methods and of the indicators, and on the relevancy of results. Evaluation and comparative studies are therefore needed to answer such issues. Here, we present four recent comparative studies selected for their illustrative value, first, to analyse the methodologies used for comparison of methods, and second, to highlight the main results of the four comparisons. The first study involves 23 indicators to address nitrate leaching. The second study involves 43 indicators to address pesticide risk. The third and fourth studies compare environmental assessment methods based on 4-5 indicators used in French and Upper Rhine plains (France, Germany and Switzerland). Both studies also compare the outputs of the methods and highlight the low degree of convergence between them. The approach proposed in the last study is the most elaborate among the four case studies. It could be used to develop a generic evaluation and comparison methodology. The review of those four case studies shows the need to formalise the methodology underlying any comparison work of indicators or evaluation methods.
اظهر المزيد [+] اقل [-]Comparison of methods to assess the sustainability of agricultural systems. A review
2009
Bockstaller, Christian | Guichard, Laurence | Keichinger, Olivier | Girardin, Philippe | Galan, Marie-Béatrice | Gaillard, Gérard
Since the 1990s, numerous agri-environmental indicators and indicator-based methods have been developed to assess the adverse effects of cropping and farming systems such as water pollution by nitrates and pesticides, and gaseous emissions due to nitrogen inputs. This wealth of environmental indicators and assessment methods based on indicators raises issues on the quality of the methods and of the indicators, and on the relevancy of results. Evaluation and comparative studies are therefore needed to answer such issues. Here, we present four recent comparative studies selected for their illustrative value, first, to analyse the methodologies used for comparison of methods, and second, to highlight the main results of the four comparisons. The first study involves 23 indicators to address nitrate leaching. The second study involves 43 indicators to address pesticide risk. The third and fourth studies compare environmental assessment methods based on 4–5 indicators used in French and Upper Rhine plains (France, Germany and Switzerland). Both studies also compare the outputs of the methods and highlight the low degree of convergence between them. The approach proposed in the last study is the most elaborate among the four case studies. It could be used to develop a generic evaluation and comparison methodology. The review of those four case studies shows the need to formalise the methodology underlying any comparison work of indicators or evaluation methods.
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