Demography

@article{cole1957sketches,
    author = "Cole, L. C.",
    title = "Sketches Of General and Comparative Demography",
    year = "1957",
    journal = "Cold Spring Harbor Symposia on Quantitative Biology",
    url = "https://doi.org/10.1101/sqb.1957.022.01.004",
    doi = "10.1101/sqb.1957.022.01.004",
    number = "0",
    openalex = "W2327592758",
    pages = "1-15",
    volume = "22"
}

@inproceedings{cole1958sketches2,
    author = "Cole, L. C",
    title = "Sketches of general and comparative demography",
    year = "1958",
    booktitle = "Cold Spring Harbor Symposium on Quantitative Biology, v. 22, p. 1-15",
    note = "talkorigins\_source = {true}; raw\_reference = {Cole, L. C., 1958, Sketches of general and comparative demography: Cold Spring Harbor Symposium on Quantitative Biology, v. 22, p. 1-15.}"
}

@misc{cole1960competitive3,
    author = "Cole, L. C",
    title = "Competitive exclusion",
    year = "1960",
    howpublished = "Science, v. 132, p. 348-349",
    note = "talkorigins\_source = {true}; raw\_reference = {Cole, L. C., 1960, Competitive exclusion: Science, v. 132, p. 348-349.}"
}

@book{bogue1969principles1,
    author = "Bogue, D. J",
    title = "Principles of Demography",
    year = "1969",
    publisher = "New York, Wiley",
    note = "talkorigins\_source = {true}; raw\_reference = {Bogue, D. J., 1969, Principles of Demography: New York, Wiley.}"
}

It is shown in this paper that no stable equilibrium can be attained in an ecological community in which some r of the components are limited by less than r limiting factors. The limiting factors are thus put forward as those aspects of the niche crucial in the determination of whether species can coexist. For example, consider the following simple food web: Despite the similar positions occupied by the two prey species in this web, it is possible for them to coexist if each is limited by an independent combination of predation and resource limitation, since then two independent factors are serving to limit two species. On the other hand, if two species feed on distinct but superabundant food sources, but are limited by the same single predator, they cannot continue to coexist indefinitely. Thus these two species, although apparently filling distinct ecological niches, cannot survive together. In general, each species will increase if the predator becomes scarce, will decrease where it is abundant, and will have a characteristic threshold predator level at which it stabilizes. That species with the higher threshold level will be on the increase when the other is not, and will tend to replace the other in the community. If the two have comparable threshold values, which is certainly possible, any equilibrium reached between the two will be highly variable, and no stable equilibrium situation will result. This is not the same as dismissing this situation as "infinitely unlikely," which is not an acceptable argument in this case. Hutchinson's point of the preceding section vividly illustrates this. The results of this paper improve on existing results in three ways. First, they eliminate the restriction that all species are resource-limited, a restriction persistent in the literature. Second, the results relate in general to periodic equilibria rather than to constant equilibria. Third, the nature of the proof relates to the crucial question of the behavior of trajectories near the proposed equilibrium, and provides insight into the behavior of the system when there is an insufficient number of limiting factors.

@article{doi101086282676,
    author = "Levin, Simon A.",
    title = "Community Equilibria and Stability, and an Extension of the Competitive Exclusion Principle",
    year = "1970",
    journal = "The American Naturalist",
    abstract = {It is shown in this paper that no stable equilibrium can be attained in an ecological community in which some r of the components are limited by less than r limiting factors. The limiting factors are thus put forward as those aspects of the niche crucial in the determination of whether species can coexist. For example, consider the following simple food web: Despite the similar positions occupied by the two prey species in this web, it is possible for them to coexist if each is limited by an independent combination of predation and resource limitation, since then two independent factors are serving to limit two species. On the other hand, if two species feed on distinct but superabundant food sources, but are limited by the same single predator, they cannot continue to coexist indefinitely. Thus these two species, although apparently filling distinct ecological niches, cannot survive together. In general, each species will increase if the predator becomes scarce, will decrease where it is abundant, and will have a characteristic threshold predator level at which it stabilizes. That species with the higher threshold level will be on the increase when the other is not, and will tend to replace the other in the community. If the two have comparable threshold values, which is certainly possible, any equilibrium reached between the two will be highly variable, and no stable equilibrium situation will result. This is not the same as dismissing this situation as "infinitely unlikely," which is not an acceptable argument in this case. Hutchinson's point of the preceding section vividly illustrates this. The results of this paper improve on existing results in three ways. First, they eliminate the restriction that all species are resource-limited, a restriction persistent in the literature. Second, the results relate in general to periodic equilibria rather than to constant equilibria. Third, the nature of the proof relates to the crucial question of the behavior of trajectories near the proposed equilibrium, and provides insight into the behavior of the system when there is an insufficient number of limiting factors.},
    url = "https://doi.org/10.1086/282676",
    doi = "10.1086/282676",
    openalex = "W2061867342",
    references = "doi101086282160, doi1023071929896"
}

@incollection{crossref2008competitive,
    title = "Competitive Exclusion",
    year = "2008",
    booktitle = "Encyclopedia of Genetics, Genomics, Proteomics and Informatics",
    url = "https://doi.org/10.1007/978-1-4020-6754-9\_3413",
    doi = "10.1007/978-1-4020-6754-9\_3413",
    openalex = "W4239686931",
    pages = "399-399"
}

@misc{maillard2013general,
    author = "Maillard, Pierre",
    title = "General Principles of Competitive Quality",
    year = "2013",
    booktitle = "Competitive Quality Strategies",
    url = "https://doi.org/10.1002/9781118644454.ch1",
    doi = "10.1002/9781118644454.ch1",
    openalex = "W1560771216",
    pages = "1-16"
}

Citation: 'competitive exclusion' in the IUPAC Compendium of Chemical Terminology, 5th ed.; International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.14538 • License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International for individual terms. Requests for commercial usage of the compendium should be directed to IUPAC.

@misc{crossref2025competitive,
    title = "competitive exclusion",
    year = "2025",
    booktitle = "The IUPAC Compendium of Chemical Terminology",
    abstract = "Citation: 'competitive exclusion' in the IUPAC Compendium of Chemical Terminology, 5th ed.; International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.14538 • License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International for individual terms. Requests for commercial usage of the compendium should be directed to IUPAC.",
    url = "https://doi.org/10.1351/goldbook.14538",
    doi = "10.1351/goldbook.14538",
    openalex = "W4406007935",
    references = "doi101351pacrec080709"
}

Synopsis Dilution effects arise when increases in species diversity reduce disease risk, and amplification effects arise when the opposite occurs. Despite ample evidence for both phenomena, the mechanisms driving dilution and amplification effects and how they are mediated by environmental factors remain poorly understood. Mechanisms involving demographic rates or stage structure of hosts are particularly lacking in the diversity–disease literature. In Midwestern lakes, Metschnikowia bicuspidata parasites infect Daphnia dentifera focal hosts in autumn, with epidemics beginning when water is warm (∼25°C) and peaking when lakes have cooled (∼15°C). Epidemics are smaller in lakes with more Ceriodaphnia dubia alternative hosts, which serve as key diluters of disease. However, it is unclear whether seasonal changes in temperature affect their ability to alter host population dynamics and reduce disease. We conducted a mesocosm experiment to test how temperature (15, 20, or 25°C) mediated the effects of these key alternative hosts on density, stage structure, and disease dynamics in focal host populations. The experiment yielded several surprising results. First, focal hosts rapidly outcompeted alternative hosts at all temperatures. By the time parasites were added, alternative hosts had been almost completely excluded. Second, despite diluting disease in the field, initial presence of these alternative hosts amplified infection prevalence in the experiment. Third, this amplification arose as a legacy effect, lasting generations after alternative hosts were gone. Our explanation for this legacy amplification effect centers on focal host stage structure and demography. Competition with alternative hosts resulted in focal host populations that were more adult-biased when parasites were added, at all 3 temperatures. Additionally, host densities in these treatments increased more rapidly in the subsequent 10 days, consistent with reduced background death rates. Since adults consume more parasites than juveniles, and since exposed hosts must survive 10 days before producing infectious spores, these initial differences in stage structure and population growth seem to have set disease dynamics along amplified trajectories. These results highlight the need for a broader understanding of the mechanisms that can amplify or dilute disease, including altered host stage structure and mortality of exposed hosts in diverse communities.

@article{suh2025a,
    author = "Suh, Daniel C and Schroeder, Katie and Landolt, Emily F and Tejada, Jenavier and Strauss, Alexander T",
    title = "A legacy of competitive exclusion: Host demography and amplified disease",
    year = "2025",
    journal = "Integrative And Comparative Biology",
    abstract = "Synopsis Dilution effects arise when increases in species diversity reduce disease risk, and amplification effects arise when the opposite occurs. Despite ample evidence for both phenomena, the mechanisms driving dilution and amplification effects and how they are mediated by environmental factors remain poorly understood. Mechanisms involving demographic rates or stage structure of hosts are particularly lacking in the diversity–disease literature. In Midwestern lakes, Metschnikowia bicuspidata parasites infect Daphnia dentifera focal hosts in autumn, with epidemics beginning when water is warm (∼25°C) and peaking when lakes have cooled (∼15°C). Epidemics are smaller in lakes with more Ceriodaphnia dubia alternative hosts, which serve as key diluters of disease. However, it is unclear whether seasonal changes in temperature affect their ability to alter host population dynamics and reduce disease. We conducted a mesocosm experiment to test how temperature (15, 20, or 25°C) mediated the effects of these key alternative hosts on density, stage structure, and disease dynamics in focal host populations. The experiment yielded several surprising results. First, focal hosts rapidly outcompeted alternative hosts at all temperatures. By the time parasites were added, alternative hosts had been almost completely excluded. Second, despite diluting disease in the field, initial presence of these alternative hosts amplified infection prevalence in the experiment. Third, this amplification arose as a legacy effect, lasting generations after alternative hosts were gone. Our explanation for this legacy amplification effect centers on focal host stage structure and demography. Competition with alternative hosts resulted in focal host populations that were more adult-biased when parasites were added, at all 3 temperatures. Additionally, host densities in these treatments increased more rapidly in the subsequent 10 days, consistent with reduced background death rates. Since adults consume more parasites than juveniles, and since exposed hosts must survive 10 days before producing infectious spores, these initial differences in stage structure and population growth seem to have set disease dynamics along amplified trajectories. These results highlight the need for a broader understanding of the mechanisms that can amplify or dilute disease, including altered host stage structure and mortality of exposed hosts in diverse communities.",
    url = "https://doi.org/10.1093/icb/icaf035",
    doi = "10.1093/icb/icaf035",
    number = "2",
    openalex = "W4410313260",
    pages = "403-414",
    volume = "65",
    references = "doi1010079781441903181, doi101017cbo9780511565403, doi101017s0031182012000200, doi101038nature11883, doi101046j15231739200099014x, doi101073pnas0233733100, doi101073pnas1506279112, doi101111j14610248200600885x, doi101146annurevecolsys102710145022, doi1018900012965820020831713eogpsd20co2"
}