10.5061/DRYAD.49TD812
Germain, Rachel M.
University of British Columbia
Grainger, Tess N.
University of Toronto
Jones, Natalie T.
University of California, San Diego
Gilbert, Benjamin
University of Toronto
Data from: Maternal provisioning is structured by species’ competitive
neighborhoods
Dryad
dataset
2018
maternal effects
annual plants
2018-09-05T15:12:53Z
2018-09-05T15:12:53Z
en
https://doi.org/10.1111/oik.05530
47498 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Differential maternal provisioning of offspring in response to
environmental conditions has been argued as ‘the missing link’ in plant
life histories. Although empirical evidence suggests that maternal
provisioning responses to abiotic conditions are common, there is little
understanding of how differences in maternal provisioning manifest in
response to competition. Frequency manipulations are commonly employed in
ecological studies to assess the strength of interspecific competition,
relative to intraspecific competition, and we used frequency manipulations
to test how competition in two soil moisture environments affects maternal
provisioning of seed mass. Specifically, for 15 pairs comprised from 25
annual plant species that occur in California, we varied the relative
frequencies of conspecific to heterospecific competitors from 90%
(intraspecific competition) to 10% (interspecific competition). We found
that conspecific frequency affected maternal provisioning (seed mass) in
12 of the 25 species (8 significantly (P<0.05), four marginally
significantly (P<0.07)), and that these responses included both
increased (5 species) and decreased (6 species) seed mass, as well as one
species with opposing directions of response to conspecific frequency that
depended on the soil moisture environment. Conspecific frequency also
affected per capita fecundity (seed number) for 17 of the 25 species (15
significantly (P<0.05), two marginally significantly
(P<0.09)), which generally decreased seed number as conspecific
frequency increased. The direction and magnitude of frequency-dependent
seed mass depended on the identity of the competitor, even among species
whose fecundity was not affected by competitor identity; the latter
finding reveals competitive differences among species that would otherwise
appear to be competitively equivalent. Our research demonstrates how
species responses to different competitive environments manifest through
maternal provisioning, and that these responses alter previous estimates
of environmentally-determined maternal provisioning and reproductive
output; future study is needed to understand their combined effects on
population and community dynamics.
alpha only w phylopaper seed number dataSeed size/number data from portion
of experiment where species were grown in pairwise
competitiondata.lambdaSeed size data when species grown alone at low
densities