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Synthesis proposal for PAInt, UNR
Christopher Moore
30 September 2013
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arrive in areas where they may find sufficient resources to survive and reproduce. Like all traits,
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dispersal is an evolutionary outcome of selection against ancestral lineages with dispersal-related
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and other fitness-affecting traits that insufficiently acquire resources to survive and reproduce,
Proposal: Dispersal-mass relationships
Dispersal is a process whereby organisms escape density-dependent factors in space or time to
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given their respective environments. Dispersal can accordingly be interpreted as the trait
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mediating the spatial scale at which organisms interact with their environment, both biotic and
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abiotic.
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If ecologists are interested in the spatial and temporal patterns of the distribution and
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abundance of organisms, including causes and consequences1, then a robust understanding of
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patterns of mediating the spatial scale at which organisms interact with their environment (i.e.,
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dispersal) is imperative. Gathering empirical data on dispersal in the laboratory and field is often
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difficult due to the large spatial scales that need to be sampled, so dispersal biology has
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historically largely been theoretical because of the paucity of empirical data. Nonetheless, recent
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years in methodological advances and awareness of dispersal and movement ecology2 have
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yielded greater attention to dispersal3. In the 25 years since dispersal biology began logistic
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growth in the number of studies, there have been various, but few, syntheses on the topic.
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Concurrent with studies in dispersal, ecologists have also experienced the emergence of a
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subfield that is a resurgence of early ecology's roots of a top-down, holistic approach (e.g.,
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Clemensian ecology, the Arrhenius law, Preston's species-abundance distributions),
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marcoecology. Some of the large-scale patterns incorporated into the macroecological paradigm
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include: Kleiber allometry (mass-metabolic rate relationship: bmr = mass3/4), mass-generation
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time relationship: generation time = constant  mass0.27, Fenchel's allometry (mass-growth rate
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relationship: rmax = constant  mass-0.26), Damuth's allometry (mass-density relationship: density
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= constant  mass-0.76), and Calder's allometry (mass-population cycle period relationships:
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constant  mass0.26). Curiously, there is no literature to my knowledge that has attempted to
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synthesize the relationship between dispersal and other ecologically meaningful traits across
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deeply diverged taxa.
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Herein, I propose a synthesis of the trove of dispersal studies. Primarily, I think that there are
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enough studies that have studied dispersal distance to relate it to body mass, therefore allowing
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quantitative synthesis of the spatial scale at which organisms interact with their environment.
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Secondarily, I think there are other informative comparisons with enough data that could be
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made to dispersal distance, that at least need to be controlled for, including, for example: range
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size, social system, latitude, and trophic position. Because this is a field in which I actively
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research, I can say with a good deal of confidence that there is enough data, and extractable data
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from dispersal studies.
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This would be exploratory synthesis testing the prediction that there is a relationship between
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dispersal distance and organismal mass if the hypothesis that dispersal mediates the degree to
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which organisms interact with their environment is true.
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From Scheiner and Willig, 2008, Theor. Ecol. 1:21–28; see table 1 for other definitions.
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A 2006 Science Special Issue: http://www.sciencemag.org/content/313/5788.toc#SpecialIssue, a 2008 Special
Feature in PNAS: http://www.pnas.org/cgi/collection/movt_ecology, and a new journal of this year Movement
Ecology: http://www.movementecologyjournal.com/.
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A Web Of Science search for the word "dispersal," ranked by frequency: