Use Of Ecological Models Research Articles

A Person-Oriented Approach to Characterizing Beginning Teachers in Alternative Certification Programs

In this article, the authors argue for the use of ecological models of development in studies of teachers prepared through alternative certification (AC) programs. Previous studies of candidates in AC programs have focused on variables that describe their demographic characteristics. An ecological approach focuses on persons and situates their desires and attitudes toward teaching as shaped by their particular life circumstances and personal histories. This approach was applied to a large-scale study of individuals enrolled in California’s teacher internship program. The results are the development of six typological profiles that capture some of the complexities behind why individuals choose to enter teaching through AC routes.

Ecological niche modeling and geographic distribution of the genus Polianthes L. (Agavaceae) in Mexico: using niche modeling to improve assessments of risk status

The genus Polianthes (Agavaceae) is endemic to Mexico and is important at the scientific, economical, and cultural level since prehispanic times. Habitat destruction is one of the main factors affecting populations of Polianthes species, yet little is known about the geographic distribution of this genus, and thus its vulnerability to habitat change. We compared three different approaches to measure the Polianthes species area of distribution to assess the risk of species extinction applying the MER (Method of Evaluation of Risk extinction of wild species for Mexico): area of occupancy, extent of occurrence, and ecological modeling. We also found the richness areas of distribution of this genus. We compared the species distributions with Terrestrial Protected Regions (TPR) and Natural Protected Areas (NPA). Although the three methods used to calculate the species area of distribution agree about the highly restricted nature of Polianthes species. The area of occupancy sub-estimate the species distribution, while the extent of occurrence over-estimate it for species with disjoint distribution. Thus, we recommend the use of ecological modeling to improve the assessment of the current species distribution area to apply the MER. Most Polianthes species are distributed in the Sierra Madre Occidental and Transvolcanic Belt. Three species do not occur in any of the NPA or TPR, one species has suitable habitat in three TPR but has not been recorded there, and one species, P. palustris, is likely extinct.

Potential Applications of Population Viability Analysis to Risk Assessment for Invasive Species

ABSTRACT Population viability analysis, the use of ecological models to assess a population's risk of extinction, plays an important role in contemporary conservation biology. The premise of this review is that models, concepts, and data analyses that yield results on extinction risk of threatened and endangered species can also tell us about establishment risks of potentially invasive species. I briefly review important results for simple unstructured models, demographic models, and spatial models, giving examples of the application of each type of model to invasive species, and general conclusions about the applicability of each type of model to risk analysis for invasive species. The examples illustrate a portion of the range of potential applications of such models to invasive species, and some of the types of predictions that they can provide. They also highlight some of the limitations of such models. Finally, I present several conjectures and open research questions concerning the application of population viability analyses to risk analysis and control of invasive species.

Characterizing aquatic ecological risks from pesticides using a diquat dibromide case study III. Ecological process models

AbstractThe purpose of this study was to add to the set of risk characterization approaches developed in an earlier study beyond simple comparisons of exposure and effects (e.g., quotients, overlapping frequency distributions) through use of ecological models. These models were used to evaluate the ecological risks from diquat dibromide for individual Daphnia using an individual‐oriented model, a population of bluegill sunfish (Lepomis macrochirus) using a demographic model, and ecological communities within a generic lake in Central Florida, USA, using the Comprehensive Aquatic Systems Model. The ecological models presented in this study more realistically address the potential risks posed by pesticides to individual organisms, populations, communities, and ecosystems than risk assessment methods based on simple comparisons of exposure and effects. The ecological impacts calculated by these models support the inference of minimal risks being posed by diquat dibromide to aquatic systems as concluded from previous empirical comparisons of exposure and toxicity data.

Intellectual disability and ageing: ecological perspectives from recent research.

Ageing in people with intellectual disabilities has become a central concern of service providers and research workers during the past 20 years. Their emergence as an identifiable population of older people with intellectual disabilities reflects, in part, improvements in medical and social service provision. However, interest in this group is primarily a reflection of the fact that, despite services developed in the light of principles of normalization, they remain readily identifiable as people in receipt of specialist intellectual disability services, in consequence typically clearly differentiated from the mainstream of older people generally. Analysis of this situation and other factors impacting on older people with intellectual disabilities can be undertaken through the use of ecological models conceptualized in terms of interacting, nested ecologies. The emergence of research on the impact of cultural influences on family carers and service provision is addressed within the framework of the ecological model, and methodological cautions are offered. The enduring the role of family carers and their motivation to continue caring is described.

Sensitivity of the thermal stratification model eddy diffusion dimension 1 using a factorial experimental design

Engineering use of ecological models requires, as a precondition, appropriate validation and sensitivity testing. Using one such well‐validated thermal stratification model, the application of an industrial statistical technique for multifactor sensitivity testing is described. This method, of fractional factorial numerical experimentation, permits identification of important model parameters (here wind speed and internal mixing mechanisms), as well as potential interactions between two or more factors.

WHAT IS THE ROLE OF SCIENCE IN THE DIALOGUE PROPOSED BY WILLIAM KLINK?

Abstract. Klink rejects the use of ecological models in environmental decision making because their predictions cannot be tested by rigorous scientific methods. I argue that models that cannot be tested according to the rigorous standards of the physical sciences can still be considered “scientific”; they are useful (and, in practice, used) for assessing the impacts of human actions on the environment and choosing between alternative courses of action. It is, however, important to be aware of the uncertainties and to make corrections as new data and insights become available. The interplay between (1) model‐based decisions and action and (2) their consequences and subsequent corrections can be regarded as a dialogue between humans and nature (or God) in the sense proposed by Klink. Klink also claims that future actions should be informed by the larger vision of theology and should not be based on science. I suggest that science has an indispensible role. The larger vision is needed to respond to the fundamental religious question: How should I live—and why? But this question cannot be answered without first addressing the fundamental scientific question: How does the world work? I suggest that responses to the first question can be formulated as visions of a future state of existence that we feel compelled to strive to realize, and that science is necessary to provide “maps of reality” needed to realize visions. I also suggest that Christian traditions can probably provide adequate visions; the crucial need is for improving our “maps of reality.”

The use of ecological modeling in geographical information systems: the prediction of LD50 species mortality from fire intensity: M.R. Kunzmann, P.S. Bennett & G. Ball, in: Resource Technology 90. Proc. second international symposium on advanced technology in natural resources management, Washington, DC, 1990, ed G.J. Buhyoff, (ASPRS), 1991, pp 118–127

The use of ecological modeling in geographical information systems: the prediction of LD50 species mortality from fire intensity: M.R. Kunzmann, P.S. Bennett & G. Ball, in: Resource Technology 90. Proc. second international symposium on advanced technology in natural resources management, Washington, DC, 1990, ed G.J. Buhyoff, (ASPRS), 1991, pp 118–127

On the careful use of ecological models

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Environment, Subsistence and System: The Ecology of Small-Scale Social Formations

Human ecology is ultimately part of a general theory of society. This is the argument developed here by Roy Ellen, whose exploration of the interplay between social organization and ecology in small-scale subsistence systems has direct bearings both on the investigation of human environmental relations in general and on contemporary social theory. He argues that while ecological study of non-industrial societies cannot be elevated to the status of theory, domain or discipline, it can be represented as a single 'problematic' that historically has acquired some degree of autonomy and which continues to make a significant contribution to a wider anthropology. Dr Ellen introduces his subject matter through an extended and systematic discussion of some major frameworks developed within the last hundred years to examine and explain facets of the relationship between culture, social organization and the environment: determinism, possibilism, cultural ecology, systems theory and ideas derived from modern biology. He follows this with a detailed review and appraisal of important recent research involving the use of ecological models, methods and data. This original and innovative study of the pre-eminently social character of human ecological relations will be of considerable interest to all students and researchers concerned with understanding the nature of the relationship between human beings and their environments.

The Southwest and the Plains: Ecology and Economics

The ecological concept of niche is used to provide a better understanding of prehistoric interactions between the Plains and the Puebloan Southwest. A diachronic model is presented based on concepts of energy flow and regional microvariation in net energy input. At a general level, such use of ecological models and principles enables changes in human systems to be seen as an example of a general increase in ecosystem complexity. The application of more powerful theoretic and methodological concepts and constructs can then lead to a more powerful theory of human cultural evolution.

The Usefulness of Ecological Models: A Stock-Taking

Mathematical modeling forms a large part of modern ecological research. This essays argues that it forms too large a part. The uses of modeling are reviewed: models are used to "explain" the functioning of natural ecosystems; they are also used in forecasting, in hypothesis-generation, and as standards of comparison. Although the original task of models was to explain nature, this is the task they perform least well. To compare a model with reality is, in effect, to ask a number of questions simultaneously when they could more profitably be tackled be tackled individually. The search for answers to single "unit" questions, here called "investigating," is more likely than modeling to yield advances in knowledge. It is not easy, as examples show.

Ecological models in estuarine management

Abstract Current practice in the use of ecological models in water quality management of estuaries is almost exclusively restricted to very simple models of dissolved oxygen and biochemical oxygen demand; these models ignore almost the entire range of ecological interactions which actually occur in large estuaries and which transform organic matter and modify oxygen levels, yet nevertheless they are capable of realistic simulation and prediction. It is suggested that this is often because the modelled ecosystems are simplified due to pollution and/or very short water residence-time in the estuaries being modelled. More comprehensive ecological simulation models of estuaries are now being tested, and the nature of their output, and their application to practical estuarine water quality management are reviewed. It is suggested that the most comprehensive models have as their main role the understanding of the nature of simulations performed by simple models, and most importantly, in the prediction of the effects of major climatic or technological changes to estuaries. For instance, the effects of tidal power generation schemes, as proposed for Severn and Fundy, can only be predicted by large comprehensive models such as the NERC GEMBASE. Without the use of such models, prediction must be non-quantitative even if it is objective.

Comments on the Use of Ecological Models in the Study of Residential Mobility in the City

(1971). Comments on the use of Ecological Models in the Study of Residential Mobility in the City. Economic Geography: Vol. 47, PERSPECTIVES ON URBAN SPATIAL SYSTEMS, pp. 73-85.