DOI: 10.5061/dryad.n11s7
title: Data from: Interference versus exploitative competition in the regulation of size-structured populations

description: Competition is a major regulatory factor in population and community
 dynamics. Its effects can be either direct in interference competition or
 indirect in exploitative competition. The impact of exploitative
 competition on population dynamics has been extensively studied from
 empirical and theoretical points of view, but the consequences of
 interference competition remain poorly understood. Here we study the
 effect of different levels of intraspecific interference competition on
 the dynamics of a size-structured population. We study a physiologically
 structured population model accounting for direct individual interactions,
 allowing for a gradient from exploitative competition to interference
 competition. We parameterize our model with data on experimental
 populations of the collembolan Folsomia candida. Our model predicts
 contrasting dynamics, depending on the level of interference competition.
 With low interference, our model predicts juvenile-driven generation
 cycles, but interference competition tends to dampen these cycles. With
 intermediate interference, giant individuals emerge and start dominating
 the population. Finally, strong interference competition causes a novel
 kind of adult-driven generation cycles referred to as interference-induced
 cycles. Our results shed new light on the interpretation of the
 size-structured dynamics of natural and experimental populations.
description: Individual clutch sizes
 and body lengthThe collembolans are
 maintained in the laboratory in polyethylene vials (diameter 52mm, height
 65mm) filled with a 30 mm width layer of a plaster of Paris mixed with
 Indian ink to facilitate detection of the individuals. Food is provided
 weekly in the form of small dried pellets of a mixture of agar and dried
 yeast in standardized concentration and volume (Tully and Ferrière, 2008).
 The rearing boxes are maintained in incubators at 21+/-0.5°C and the
 plaster is kept wet to have a constant humidity within the boxes (~100%
 RH). We monitored 220 isolated individuals and regularly measured their
 body size and fecundity (clutch sizes).longpontfull.txtIndividual growth trajectoriesThe collembolans are maintained in the laboratory in polyethylene vials (diameter 52mm, height 65mm) filled with a 30 mm width layer of a plaster of Paris mixed with Indian ink to facilitate detection of the individuals. Food is provided weekly in the form of small dried pellets of a mixture of agar and dried yeast in standardized concentration and volume (Tully and Ferrière, 2008). The rearing boxes are maintained in incubators at 21+/-0.5°C and the plaster is kept wet to have a constant humidity within the boxes (~100% RH). We monitored 220 isolated individuals and regularly measured their body size and fecundity (clutch sizes).ucnaim.txtTime series of population plotted in Figure 5The collembolans are maintained in the laboratory in polyethylene vials (diameter 52mm, height 65mm) filled with a 30 mm width layer of a plaster of Paris mixed with Indian ink to facilitate detection of the individuals. Food is provided weekly in the form of small dried pellets of a mixture of agar and dried yeast in standardized concentration and volume. Data gives the body length and date of measurement for each individual for the whole time series.HA26r3.txt