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This paper focuses on the difference between the value of some commonly used diversity indices (Simpson, Shannon, abundance, richness) calculated from benthic grab samples and their value in the population or region from which the...
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This paper focuses on the difference between the value of some commonly used diversity indices (Simpson, Shannon, abundance, richness) calculated from benthic grab samples and their value in the population or region from which the samples are taken. The ability of the sample indices, as well as a recently derived relative Shannon index, to reflect change in biodiversity is examined in a short simulation study based on changing one of the diversity parameters (abundance, richness and evenness) in the population, whilst keeping the other two components constant. Our results suggest that, whilst their population equivalents do not always reflect biodiversity changes, the sample Simpson, Shannon and Richness indices perform well. We note that this will be true for any surveys where the sampling programme fails to detect many species in a population, and hence will be applicable for most benthic surveys. The use of sample indices to detect changes in biodiversity from long-running time series in the Thames and Tyne estuaries is illustrated.
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In this paper some tendencies of indicator development and application are presented from a quantitative and a qualitative point-of-view. The results of a mainly statistical analysis of the first twenty volumes of the journal Ecol...
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In this paper some tendencies of indicator development and application are presented from a quantitative and a qualitative point-of-view. The results of a mainly statistical analysis of the first twenty volumes of the journal Ecological Indicators are described and discussed. The focus of this investigation has been set on five questions:. (A) Which types of ecological indicators have been applied and how frequently have they been used? (B) In which management context have the indicators been applied? (C) Which integrative tools have been utilized to present the results in an aggregated form? (D) Has a theory for the application and interpretation of ecological indicators been developed? (E) Which are the resulting challenges in indicator development and application? The answers to the first three questions are given in tables and figures, while the fourth question is answered shortly and with references to the key papers that are covering the theoretical considerations behind the application of ecological indicators. Discussing the focal challenges it is foreseen that two theoretical questions will require enhanced attention the coming years: to apply fewer and more general indices and to translate the multitude of indicators to the concept of sustainability that covers the ecological-sociological-economic and political background of the overall indication activities. Furthermore, the general demands for aggregation and integration and an assessment of normative loadings in indicator systems are listed as focal tasks for future development in the field.
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Items (or indicators) that constitute "quality of life" instruments can be classified as either reflective (manifestations of some underlying construct), causal (the construct is an effect of the indicators), or composite (the con...
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Items (or indicators) that constitute "quality of life" instruments can be classified as either reflective (manifestations of some underlying construct), causal (the construct is an effect of the indicators), or composite (the construct is an exact linear combination of the indicators). Psychometric methods based on inter-item associations are only appropriate for reflective indicators, whereas other statistical and non-statistical validation methods can be used for composite or causal indicators. Thus, the distinction has important practical, as well as theoretical, implications. Attempts have been made to empirically identify which items of the EORTC QLQ-C30, a cancer-specific instrument, are causal and which are reflective. Such attempts, however, first require commitment to a particular definition of quality of life, of which there are many. Whether an indicator forms a composite, is causal or reflective of quality of life will depend on the definition adopted, and therefore, the reflective-composite-causal distinction is, arguably, best established on conceptual rather empirical grounds, guided by the "mental experiments" suggested by Bollen (Structural equations with latent variables, Wiley, New York, 1989). Conceptual models of health status and quality of life, as well as a cognitive-linguistic approach to quality of life assessment, may make some contribution to this practice. Theoretical consideration of indicator content can guide not only instrument development and validation, but also the selection of an appropriate instrument.
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Prairie management and restoration have traditionally Iemphasized plant communities but could benefit from the development of ecological indicators that incorporate animal communities to provide tangible benchmarks of ecosystem fu...
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Prairie management and restoration have traditionally Iemphasized plant communities but could benefit from the development of ecological indicators that incorporate animal communities to provide tangible benchmarks of ecosystem function and process (Hodkinson and Jackson 2005). Arthropods are useful bioindicators in terrestrial and aquatic systems because, in addition to being diverse and abundant, they represent key components in foo d webs, nutrient cycles, plant reproduction, and soil formation (Hodkinson and Jackson 2005, Kremen et al. 1993).
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Of the many analytical methods used in the determination of steady state reliability indices of discrete capacity systems, the method of state space decomposition is one of the most effective, because of its ability to work with s...
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Of the many analytical methods used in the determination of steady state reliability indices of discrete capacity systems, the method of state space decomposition is one of the most effective, because of its ability to work with sets of states rather than individual states. In the past, decomposition-based methods have been used mostly for determining only probability indices; in those cases where they have been used to determine frequency and duration indices, the process has been cumbersome. This paper describes a technique for the determination of frequency and duration indices using the method of state space decomposition. For the first time direct, closed form expressions are developed and presented, and an efficient implementation is outlined. The approach is illustrated by means of a numerical example and validated using an enumeration-based method.
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Companies have moral and legal obligations to avoid harm to their employees, visitors and to the environment. There are also sound business reasons for avoiding accidents. A substantial return on investment can be realised by impr...
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Companies have moral and legal obligations to avoid harm to their employees, visitors and to the environment. There are also sound business reasons for avoiding accidents. A substantial return on investment can be realised by improvements to health, safety and environmental performance which may also result in enhanced organisational productivity and financial performance. As with any other company activity therefore HSE performance-related activities need to be measured. Metrics are measures of performance of a SHE activity or programme which can steer performance of health and well-being of a worker or organisation. They should be meaningful, relevant, repeatable, simple, well-defined, comparable, economical to collect, timely, and they should facilitate trend analysis for intra and inter department/site comparison. Lagging indicators remain of value for highlighting opportunities and priorities for improvement, determining trends, confirming effectiveness of interventions, and satisfying regulatory requirements. More useful proactive 'leading' indicators can be obtained from such as near-miss investigations, site inspections, risk assessments, safety meetings, safety audits. The paper describes the development and use of KPIs in a service company outside mainstream production and major accident hazards and explains how this measurement culture will greatly assist in the future identification of sites that require additional resource or support.
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Cultivation of cover crops is a valuable practice in sustainable agriculture. In cover crop management, the method of desiccation is an important consideration, and one widely used method for this is the application of glyphosate....
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Cultivation of cover crops is a valuable practice in sustainable agriculture. In cover crop management, the method of desiccation is an important consideration, and one widely used method for this is the application of glyphosate. With use of glyphosate likely to be banned soon in Europe, the purpose of this study was to evaluate the herbicidal effect of pelargonic acid (PA) as a bio-based substitute for glyphosate. This study presents the results of a two-year field experiment (2019 and 2021) conducted in northeast Germany. The experimental setup included an untreated control, three different dosages (16, 8, and 5 L/ha) of PA, and the active ingredients glyphosate and pyraflufen. A completely randomised block design was established. The effect of the herbicide treatments was assessed by a visual estimate of the percentage of crop vitality and a comparison assessment provided by an Ebee+ drone. Four vegetation indices (VIs) calculated from the drone images were used to verify the credibility of colour (RGB)-based and near-infrared (NIR)-based vegetation indices. The results of both types of assessment indicated that pelargonic acid was reasonably effective in controlling cover crops within a week of application. In both experimental years, the PA (16 L/ha) and PA_2T (double application of 8 L/ha) treatments demonstrated their highest herbicidal effect for up to seven days after application. PA (16 L/ha) vitality loss decreased over time, while PA_2T (double application of 8 L/ha) continued to exhibit an almost constant effect for longer due to the second application one week later. The PA dosage of 5 L/ha, pyraflufen, and a mixture of the two exhibited a smaller vitality loss than the other treatments. However, except for glyphosate, the herbicidal effect of all the other treatments decreased over time. At the end of the experiment, the glyphosate treatment (3 L/ha) demonstrated the lowest estimated vitality. The results of the drone assessments indicated that vegetation indices (VIs) can provide detailed information regarding crop vitality following herbicide application and that RGB-based indices, such as EXG, have the potential to be applied efficiently and cost-effectively utilising drone imagery. The results of this study demonstrate that pelargonic acid has considerable potential for use as an additional tool in integrated crop management.
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The aims of this study was to identify the quality of the AI-Shamiyah River by using the Physicochemical and biological factors (diatoms) from March 2013 to February 2014. Two aquatic plants (Ceratophyllum demersum and Phragmites ...
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The aims of this study was to identify the quality of the AI-Shamiyah River by using the Physicochemical and biological factors (diatoms) from March 2013 to February 2014. Two aquatic plants (Ceratophyllum demersum and Phragmites australis) were selected to study epiphytic diatoms. Pollution, trophic and diversity indices were applied to assess water quality in the river. The pollution indices were Saprobic Index (S), Pollution Tolerance Index (P.T.I), Palmer Pollution Index (PPI), Index of Pollution Sensitivity (IPS) and Biological Water Quality Index (BWQI). The Trophic Indices were Percent Sensitive Species (SS %), Trophic diatom index (TDI), Diatomic Index (DI), Generic Diatom Index (GDI) and Trophic State Index (TSI). The Diversity Indices included Simpson Index (SI), Richness index (D), Shannon-Weaver index (H'), Evenness index (E) and Mcintosh Diversity Index (Mc). The results showed that Al-Shamiyah River is a slight to medium polluted, oligotrophic -mesotrophic and high diversity of diatoms. The quality of water is ranging from moderate to good quality.
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This paper aims to classify and rank rural areas in Greece using a set of technical, economic and social indicators. For this purpose, we developed appropriate indicators and criteria applied hierarchical cluster analysis and the ...
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This paper aims to classify and rank rural areas in Greece using a set of technical, economic and social indicators. For this purpose, we developed appropriate indicators and criteria applied hierarchical cluster analysis and the multicriteria method PROMETHEE Ⅱ. In order to collect the appropriate data, a household survey carried out in the context of the research project CAP-IRE (assessing the multiple impacts of the Common Agricultural Policy on Rural Economies) which is a European FP7 funded project. A sample of 300 farm households located in the 16 prefectures of Macedonia and Thrace at Northern Greece was used to classify and rank these areas.
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Context Sustainability indices (SIs) have become increasingly important to sustainability research and practice. However, while the validity of SIs is heavily dependent on how their components are weighted and aggregated, the typo...
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Context Sustainability indices (SIs) have become increasingly important to sustainability research and practice. However, while the validity of SIs is heavily dependent on how their components are weighted and aggregated, the typology and applicability of the existing weighting and aggregation methods remain poorly understood.
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