Theories and Models of Species Abundance

Hughes, R. G.

doi:10.1086/284611

Cited by 161 publications

(138 citation statements)

References 58 publications

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“…Thus, these results agree with the findings of Hanski et al (1993), which stated that the number of core species will decrease with aggregated individuals as compared to a random distribution, whereas Goodall's (1952) prediction of an increasing number of satellite species could not be confirmed. In our investigation, the total number of species sampled remained generally constant with an increasing degree of aggregation, which does not agree with Goodall (1952) and Hughes (1986), who predicted a decrease in species number. However, the size of the sample unit seems to have a greater impact on the shape of the occupancy distribution than the degree of aggregation (Fig.…”

Section: Intraspecific Aggregation Of Individualscontrasting

confidence: 99%

The shape of occupancy distributions in plant communities: the importance of artefactual effects

Kammer¹,

Vonlanthen

2009

Web Ecol.

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Occupancy frequency distributions are commonly used as an approach to describe and analyse interspecific distribution patterns. However, the relative importance of biological versus artefactual mechanisms in shaping occupancy distributions is still largely undetermined. We evaluated the importance of different and interacting artefactual effects on the shape of occupancy distributions in local plant communities. The effects of sampling protocol parameters (i.e. size and number of sample units, sample extent, coverage, and intensity) on the shape of the occupancy distributions were examined separately. We identified the mechanisms that cause the effects by tracking the shifts of individual species between occupancy classes with varying parameters. Furthermore, the impact of different species abundance distributions and increasing levels of intraspecific aggregation on occupancy distributions was investigated by means of artificial assemblages. We show the following results: 1) increases in the number of sample units, sample extent, coverage, and intensity all result in a unimodal occupancy distribution with the mode in the lowest occupancy class; 2) an increase in sample unit size leads to a bimodal distribution; 3) changes that occur in the shape of the occupancy distributions with varying sampling protocol parameters can be explained by the movements of the species between occupancy classes; 4) different species abundance distributions may cause occupancy distributions with a left-hand mode or a bimodal distribution; and 5) the number of species in the highest occupancy class decreases with increasing degree of aggregation. The mode that almost always occurs in the lowest occupancy class is most likely due to the high number of rare species existing in most communities; the mode in the highest class emerges as a pure artefact that occurs when the sample unit size is relatively large compared to the sample extent. Consequently, the exclusion or separation of concurrent artefactual mechanisms is crucial when investigating the biological causes for the shape of occupancy distributions

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Section: Intraspecific Aggregation Of Individualscontrasting

confidence: 99%

The shape of occupancy distributions in plant communities: the importance of artefactual effects

Kammer¹,

Vonlanthen

2009

Web Ecol.

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“…Although this study does not focus on singletons, but instead on relative measures of rare species, the conclusions drawn here are congruent with those of the above-mentioned previous research. It is possible that differences between tropical and non-tropical regions (which also show continental differences in this study) are the result of lower absolute densities of several tropical species (Schoener 1987, Price et al 1995, Ulrich 2001a, or that the higher frequency of rarity in the tropics may depend on different patterns of resource distribution and niche apportionment in snake communities (Hughes 1986, Tokeshi 1990, Bersier and Sugihara 1997, Kunin and Gaston 1997, Moulliot et al 2000, Novotny and Basset 2000, Ulrich 2001b, Johansson et al 2006. However, as the operational definition of rarity used in this paper (as well as in many equivalent studies) may influence the frequency results, it may also influence the latitudinal gradient and continental differences we detected because these differences are strongly connected with differences in total species richness.…”

Section: Broad Patterns Of Rarity In Snakesmentioning

confidence: 86%

Testing hypotheses on the ecological patterns of rarity using a novel model of study: snake communities worldwide

Luiselli

2006

Web Ecol.

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The theoretical and empirical causes and consequences of rarity are of central importance for both ecological theory and conservation. It is not surprising that studies of the biology of rarity have grown tremendously during the past two decades, with particular emphasis on patterns observed in insects, birds, mammals, and plants. I analyse the patterns of the biology of rarity by using a novel model system: snake communities worldwide. I also test some of the main hypotheses that have been proposed to explain and predict rarity in species. I use two operational definitions for rarity in snakes: Rare species (RAR) are those that accounted for 1% to 2% of the total number of individuals captured within a given community; Very rare species (VER) account for ≤1% of individuals captured. I analyse each community by sample size, species richness, continent, climatic region, habitat and ecological characteristics of the RAR and VER species. Positive correlations between total species number and the fraction of RAR and VER species and between sample size and rare species in general were found. As shownin previous insect studies, there is a clear trend for the percentage of RAR and VER snake species to increase in species-rich, tropical African and South American communities. This study also shows that rare species are particularly common in the tropics, although habitat type did not influence the frequency of RAR and VER species. This analysis also confirms the commonly accepted ecological hypothesis that body size and rarity are clearly and widely correlated in natural animal communities. However, in snake communities there is often an association between large and small species among the rare species, and a tendency for ophiophagous species to be rare. In addition, there was no support for the hypothesis that rare species should be typically phylogenetically primitive. The hypothesis that species with narrower realized ecological niches are more likely to be rare or very rare is supported by the evidence presented here on snake communities. In general, this study shows that snakes may make ”model organisms” for studies on the biology of rarity

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“…In the last 70 years, a series of studies have been developed aiming to understand this pattern and to generate models that reflect the species abundance distributions empirically observed (Motomura, 1932;Fisher et al, 1943;Preston, 1948;MacArthur, 1957;1960;Preston, 1962a;1962b;Caswell, 1976;Sugihara, 1980;Hughes, 1986;Tokeshi 1990;Bell, 2000;Hubbell, 2001). The initial hope of finding a mathematical model that closely fits observed data based on well established ecological and statistical theory and amenable to further tests and experiments has proved to be a difficult task.…”

Section: Introductionmentioning

confidence: 99%

Comments about some species abundance patterns: classic, neutral, and niche partitioning models

Ferreira

Petrere²

2008

Braz. J. Biol.

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The literature on species abundance models is extensive and a great deal of new and important contributions have been published in the last three decades. Broadly speaking, one can recognize five families of species abundance models: i) purely statistical or classic models (Broken-stick, Log-normal, Logarithmic and Geometric series); ii) branching process (Zipf-Mandelbrot and Fractal branching models); iii) population dynamics (Neutral models included); iv) spatial distribution of individuals (Multifractal and HEAP models) and v) niche partitioning (Sugihara´s breakage and Tokeshi models). Among these the neutral, the classic and the niche partitioning models have been the most applied to natural communities, the former having been more extensively discussed than the others in the last years. The objective of this paper is to comment some aspects of the classic, neutral and niche partitioning models in a way that the proposed distributions may contribute to the analysis of the empirical patterns of species abundance. In spite of the variety of models, the distributions in general vary between the log-normal and the logarithmic series. From these models the Power-Fraction, together with independent niche dimensions measures, are amenable to experimental tests and may offer answers on which resources are important in the structuring of biological communities.Keywords: species abundance patterns, neutral models, niche partitioning models, log-normal curve, Power fraction model. Comentários sobre alguns padrões de espécie-abundância: modelos clássicos, neutros e de partição de nicho ResumoA literatura sobre modelos de espécie-abundância é extensa e importantes contribuições têm sido publicadas nas últimas três décadas. De forma geral, são reconhecidos cinco grandes grupos de modelos: i) os que descrevem distribuições puramente estatísticas ou modelos clássicos (Broken-stick, log-normal, série logarítmica e série geométri-ca); ii) os que simulam processos de ramificação hierárquica (modelos Zipf-Mandelbrot e Fractal); iii) de dinâmica de populações (modelos Neutros); iv) de distribuição espacial de indivíduos (modelos Multifractal e HEAP); e v) de partição de nicho (modelos de Sugihara e de Tokeshi). Os modelos clássicos, os de partição de nicho e principalmente os modelos neutros têm sido os mais utilizados em estudos de comunidades naturais. O objetivo deste artigo é discutir de que forma as distribuições geradas por estes três grupos, bem com as suas bases conceituais, podem contribuir com a análise de padrões empíricos de espécie-abundância. Em geral, estes padrões variam entre as curvas log-normal e série logarítmica. Dentre a variedade de modelos existentes, o Power-fraction possibilita a simulação de uma grande amplitude de padrões de abundância relativa e é de utilização relativamente simples, podendo ser utilizado em testes experimentais de perturbação ou de sucessão ecológica. Aliado a medidas independentes de dimensões de nicho, este modelo pode ainda oferecer respostas sobre quais recursos são ess...

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Theories and Models of Species Abundance

Cited by 161 publications

References 58 publications

The shape of occupancy distributions in plant communities: the importance of artefactual effects

The shape of occupancy distributions in plant communities: the importance of artefactual effects

Testing hypotheses on the ecological patterns of rarity using a novel model of study: snake communities worldwide

Comments about some species abundance patterns: classic, neutral, and niche partitioning models

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