Search results for "Ecological systems theory"

From arctic lemmings to adaptive dynamics: Charles Elton's legacy in population ecology.

2001

We shall examine the impact of Charles S. Elton's 1924 article on periodic fluctuations in animal populations on the development of modern population ecology. We argue that his impact has been substantial and that during the past 75 years of research on multi-annual periodic fluctuations in numbers of voles, lemmings, hares, lynx and game animals he has contributed much to the contemporary understanding of the causes and consequences of population regulation. Elton was convinced that the cause of the regular fluctuations was climatic variation. To support this conclusion, he examined long-term population data then available. Despite his firm belief in a climatic cause of the self-repeating …

The irreducible uncertainty of the demography–environment interaction in ecology

2002

The interpretation of ecological data has been greatly improved by bridging the gap between ecological and statistical models. The major challenge is to separate competing hypotheses concerning demography, or other ecological relationships, and environmental variability (noise). In this paper we demonstrate that this may be an arduous, if not impossible, task. It is the lack of adequate ecological theory, rather than statistical sophistication, which leads to this problem. A reconstruction of underlying ecological processes can only be done if we are certain of either the demographic or the noise model, which is something that can only be achieved by an improved theory of stochastic ecologi…

Network Analysis: Ten Years Shining Light on Host–Parasite Interactions

2020

Biological interactions are key drivers of ecological and evolutionary processes. The complexity of such interactions hinders our understanding of ecological systems and our ability to make effective predictions in changing environments. However, network analysis allows us to better tackle the complexity of ecosystems because it extracts the properties of an ecological system according to the number and distribution of links among interacting entities. The number of studies using network analysis to solve ecological and evolutionary questions in parasitology has increased over the past decade. Here, we synthesise the contribution of network analysis toward disentangling host-parasite proces…

La teoria ecològica del desenvolupament: un marc teòric per a la comprensió del comportament humà

2008

L'any 2009 es van complir 30 anys de la publicació del llibre The Ecology of Human Development d'Urie Bronfenbrenner (1917-2005). Aquesta obra va signifi car la síntesi del pensament d'aquest autor, que ja havia esbossat en textos anteriors, i el punt de referència d'una teoria estimulant sobre el comportament humà. La idea bàsica de Bronfenbrenner és que el desenvolupament de l'individu es troba condicionat per les característiques dels entorns en què té lloc, és a dir, l'ésser humà es «fa» en interacció dinàmica amb els seus contextos i en el marc de les relacions entre aquests. Malgrat la rellevància teòrica i metodològica d'aquesta aportació, continua resultant poc coneguda per a una ma…

Ecological approach and community education as promoters of the social development of reform school students

1995

ABSTRACT New models of operation are being sought for Finnish reform school education traditionally based on segregation. This article deals with the possibilities of applying the ecological approach and community education to support the socialization of reform school students. The aim is to describe the participation of the students in one Finnish reform school, as well as their expressed need to join in the production system, cultural system, contact system and the decision‐making system of society. This article presents part of a larger project carried out at the University of Jyvaskyla in Finland. In the research project a three‐part division in the description into an ideal state, a r…

Ocean acidification through the lens of ecological theory

2015

© 2015 by the Ecological Society of America. Ocean acidification, chemical changes to the carbonate system of seawater, is emerging as a key environmental challenge accompanying global warming and other humaninduced perturbations. Considerable research seeks to define the scope and character of potential outcomes from this phenomenon, but a crucial impediment persists. Ecological theory, despite its power and utility, has been only peripherally applied to the problem. Here we sketch in broad strokes several areas where fundamental principles of ecology have the capacity to generate insight into ocean acidification's consequences. We focus on conceptual models that, when considered in the co…

Perspectives on aerosol deposition to natural surfaces: interactions between aerosol residence times, removal processes, the biosphere and global env…

1990

Abstract This paper summarizes the state-of-the-art and the research needs in the areas of aerosol residence-time assessments, deposition modelling, and understanding of aerosols in biogeochemistry. Research needs are emphasized from a systems perspective of global environmental change. Although fundamental quantitative knowledge is lacking, some qualitative linkages between source strengths, residence times, removal processes and the biosphere can be identified. It turns out that not only are the respective areas as such challenged by new problems, superimposed on the fairly well established conventional ones, but these areas also face mutually operating sets of feedbacks between residence…

An Ecological Theory of Rational Interpretation

2005

Sense of belonging to Latvia in Latvian- and Russian-speaking residents of Latvia

2019

This study examined the sense of belonging to Latvia in Latvian-speaking and Russianspeaking residents of Latvia. The structural model involved opportunities for the fulfillment of personal goals and views of the situation in Latvia and the community as predictors of the sense of belonging at both levels of ecological systems. The Russianspeaking subsample consisted of 202 students ranging in age from 18 to 36 (65% females). The Latvian-speaking subsample involved 438 students ranging in age from 18 to 37 (67% females). The Sense of Belonging in Social Context Questionnaire and the Future of Country Questionnaire were applied. Belonging to community predicted belonging to Latvia in both gro…

Inferring the Relative Resilience of Alternative States

2013

Ecological systems may occur in alternative states that differ in ecological structures, functions and processes. Resilience is the measure of disturbance an ecological system can absorb before changing states. However, how the intrinsic structures and processes of systems that characterize their states affects their resilience remains unclear. We analyzed time series of phytoplankton communities at three sites in a floodplain in central Spain to assess the dominant frequencies or "temporal scales" in community dynamics and compared the patterns between a wet and a dry alternative state. The identified frequencies and cross-scale structures are expected to arise from positive feedbacks that…