Causes and consequences of animal dispersal strategies: relating individual behaviour to spatial dynamics

Biological reviews/Biological reviews of the Cambridge Philosophical Society, Journal Year: 2005, Volume and Issue: 80(2), P. 205 - 225

Published: April 18, 2005

Knowledge of the ecological and evolutionary causes dispersal can be crucial in understanding behaviour spatially structured populations, predicting how species respond to environmental change. Despite focus much theoretical research, simplistic assumptions regarding process are still made. Dispersal is usually regarded as an unconditional although many cases fitness gains dependent on factors individual state. Condition-dependent strategies will often superior unconditional, fixed strategies. In addition, collapsed into a single parameter, despite it being composed three interdependent stages: emigration, inter-patch movement immigration, each which may display different condition dependencies. Empirical studies have investigated correlates these stages, emigration particular, providing evidence for prevalence conditional Ill-defined use term 'dispersal', across spatial scales, further hinders making general conclusions relating consequences at population level. Logistical difficulties preclude detailed study species, however incorporating unrealistic models yield inaccurate costly predictions. Further necessary explore importance specific condition-dependent dynamic

Language: Английский

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Minireview: Quantifying Landscape Spatial Pattern: What Is the State of the Art?

Ecosystems, Journal Year: 1998, Volume and Issue: 1(2), P. 143 - 156

Published: March 1, 1998

Language: Английский

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Are There General Laws in Ecology?

Oikos, Journal Year: 1999, Volume and Issue: 84(2), P. 177 - 177

Published: Feb. 1, 1999

The dictionary definition of a law is: Generalized formulation based on series events or processes observed to recur regularly under certain conditions; widely observable tendency. I argue that ecology has numerous laws in this sense the word, form widespread, repeatable patterns nature, but hardly any are universally true. Typically, other words, ecological and laws, rules mechanisms underpin them contingent organisms involved, their environment. This contingency is manageable at relatively simple level organisation (for example population dynamics single small numbers species), re-emerges also large sets species, over spatial scales, long time periods, detail-free statistical - recently called 'macroecology'. becomes overwhelmingly complicated intermediate characteristic community ecology, where there number case histories, very little than weak, fuzzy generalisations. These arguments illustrated by focusing examples typical studies way contrast, macroecological relationship emerges between local species richness size regional pool species. emergent pattern vs plots extremely simple, despite vast interactions involved its generation. To discover general patterns, may need pay less attention 'middle ground' relying reductionism experimental manipulation, increasing research efforts into macroecology.

Language: Английский

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The Matrix Matters: Effective Isolation in Fragmented Landscapes

The American Naturalist, Journal Year: 2001, Volume and Issue: 158(1), P. 87 - 99

Published: July 1, 2001

Traditional approaches to the study of fragmented landscapes invoke an island-ocean model and assume that nonhabitat matrix surrounding remnant patches is uniform. Patch isolation, a crucial parameter predictions island biogeography metapopulation theories, measured by distance alone. To test whether type interpatch can contribute significantly patch I conducted mark-recapture on butterfly community inhabiting meadows in naturally patchy landscape. used maximum likelihood estimate relative resistances two major types (willow thicket conifer forest) movement between meadow patches. For four six taxa (subfamilies or tribes) studied, was 3-12 times more resistant than willow. remaining (the most vagile least community), resistance estimates for willow were not different, indicating responses differ even among closely related species. These results suggest influence "effective isolation" habitat patches, rendering them less isolated simple classic models would indicate. Modification may provide opportunities reducing isolation thus extinction risk populations landscapes.

Language: Английский

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From Balance of Nature to Hierarchical Patch Dynamics: A Paradigm Shift in Ecology

The Quarterly Review of Biology, Journal Year: 1995, Volume and Issue: 70(4), P. 439 - 466

Published: Dec. 1, 1995

A common assumption historically in ecology is evident the term "balance of nature." The phrase usually implies that undisturbed nature ordered and harmonius, ecological systems return to a previous equilibrium after disturbances. more recent concepts point static stability, which characterize classical paradigm ecology, are traceable assumptions implicit view, however, has failed not only because conditions rare nature, but also our past inability incorporate heterogeneity scale multiplicity into quantitative expresssions for stability. theories models built around these equlibrium stability principles have misrepresented foundations resource management, conservation, environemtnal protection. In this paper, we sysntesize developments advance understandings vs. nonequilibrium, homogeneity heterogeneity, determinism stochasticity, single-sclae phenomenon hierarchical linkages systems. integration patch dynamics with hierarchy theory led new perspectives spatial temporal dynamics, explicit linkage between heterogeneity. major elements include idea nested hirarchies mosaics, ecosystem as composite changes time space, pattern-process-scale perspecitve, nonequilibrium perspective, incorporation metastability. Both enviromental stochasticities biotic feedback interactions can cause instability contribute dynamcis observed various scales. Stabilizing mechanisms dampen destabilizing forces incorporation, environmental disturbances, biological compensatory mechanisms, absorpion. Hierarchical incorporates certain "emergent properties" system, such metastabilityor persistence at meta-scale, opposed transient local phenomena. contrast derives from an assumed self-regulation closed metastability deal explicity multiple-scale processes consequences most imporatant contribution lies framework provided explicitly incorporating scale, integrating equilibrium, multiple perspectives.

Language: Английский

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On the usage and measurement of landscape connectivity

Oikos, Journal Year: 2000, Volume and Issue: 90(1), P. 7 - 19

Published: July 1, 2000

This paper examines the usage and measurement of “landscape connectivity” in 33 recent studies. Connectivity is defined as degree to which a landscape facilitates or impedes movement organisms among resource patches. However, connectivity actually used variety ways literature. has led confusion lack clarity related (1) function vs structure, (2) patch isolation and, (3) corridors connectivity. We suggest term should be reserved for its original purpose. highlight nine studies; these include modeling studies that measured accordance with definition, empirical key components found measurements provide results can interpreted recommending habitat fragmentation enhance discuss reasons this misleading conclusion, new way quantifying connectivity, avoids problem. also recommend method reducing sampling intensity landscape‐scale

Language: Английский

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Rings, circles, and null‐models for point pattern analysis in ecology

Oikos, Journal Year: 2004, Volume and Issue: 104(2), P. 209 - 229

Published: Jan. 16, 2004

A large number of methods for the analysis point pattern data have been developed in a wide range scientific fields. First‐order statistics describe large‐scale variation intensity points study region, whereas second‐order characteristics are summary all point‐to‐point distances mapped area and offer potential detecting both different types scales patterns. Second‐order based on Ripley's K‐function is increasingly used ecology to characterize spatial patterns develop hypothesis underlying processes; however, full available has seldomly applied by ecologists. The aim this paper provide guidance ecologists with limited experience help choice appropriate practical difficulties pitfalls. We review (1) analytical numerical implementation two complementary statistics, K O‐ring statistic, (2) edge correction, (3) account first‐order effects (i.e. heterogeneity) univariate patterns, (4) variety useful standard non‐standard null models bivariate For illustrative purpose, we analyze examples that deal non‐homogeneous demonstrate heterogeneity point‐pattern biases at smaller scales. This bias difficult detect without explicitly testing homogeneity, but show it can be removed when applying effects. synthesize our step‐by‐step recommendations guide reader through selection software program implements most reviewed here.

Language: Английский

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Towards a behavioral ecology of ecological landscapes

Trends in Ecology & Evolution, Journal Year: 1996, Volume and Issue: 11(3), P. 131 - 135

Published: March 1, 1996

Language: Английский

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Some general principles of landscape and regional ecology

Landscape Ecology, Journal Year: 1995, Volume and Issue: 10(3), P. 133 - 142

Published: June 1, 1995

Language: Английский

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Riverine landscapes: taking landscape ecology into the water

Freshwater Biology, Journal Year: 2002, Volume and Issue: 47(4), P. 501 - 515

Published: April 1, 2002

1. Landscape ecology deals with the influence of spatial pattern on ecological processes. It considers consequences where things are located in space, they relative to other things, and how these relationships their contingent characteristics surrounding landscape mosaic at multiple scales time space. Traditionally, ecologists have focused attention terrestrial ecosystems, rivers streams been considered either as elements mosaics or units that linked by flows across boundaries ecotones. Less often, heterogeneity exists within a river stream has viewed `riverscape' its own right. 2. can be unified about six central themes: (1) patches differ quality (2) patch affect flows, (3) context matters, (4) connectivity is critical, (5) organisms important, (6) importance scale. Although riverine systems from virtue strong physical force hydrology inherent provided water flow, all themes apply equally aquatic linkages between two. 3. therefore important insights offer study but may also provide excellent opportunities for developing testing theory. The principles approaches should extended include freshwater systems; it take `land' out ecology.

Language: Английский

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