3 research outputs found
Representative prey population dynamics.
<p>Red and blue lines in each panel give prey dynamics in two patches linked by dispersal, starting from day 20 when dispersal was initiated. (a-d) Failure to achieve synchrony with a dispersal rate of 0.125% per event, (c) slow achievement of synchrony with a dispersal rate of 5% per event, (d) rapid achievement of synchrony with a dispersal rate of 5% per event, (e) failure to achieve synchrony with dispersal rate of 2.5% per event, (f) rapid achievement of synchrony which was subsequently lost with dispersal rate of 2.5% per event, (g-h) rapid achievement of synchrony with a dispersal rate of (g) 9% or (h) 12.5% per event. Compare c-f to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0079527#pone-0079527-g001" target="_blank">Figure 1</a>.</p
Prey synchrony vs. dispersal rate.
<p>Prey synchrony (<i>z</i>-transformed cross-correlation of log<sub>10</sub>-transformed prey abundances) as a function of dispersal rate. Each open point gives results from one replicate pair of bottles. The solid curve is <i>y</i>β=β<i>ax</i>/(<i>b</i>+<i>x</i>) with estimated parameters (95% likelihood profile c.i.) of <i>a</i>β=β0.59 (0.39, 1.25), <i>b</i>β=β1.27 (0.14,8.50). The curve <i>y</i>β=β[<i>ax</i>/(<i>b</i>+<i>x</i>)][1+(1-<i>cx</i>)e<sup>β<i>cx</i></sup>] with estimated parameters (95% likelihood profile c.i.) of <i>a</i>β=β0.59 (0.45, 1.26), <i>b</i>β=β1.22 (0.45, 8.62), <i>c</i>β=β14.66 (14.66, 44.64) is hidden by the solid curve. The dotted curve is a piecewise linear regression. The black diamond indicates the estimated location and 95% confidence interval for the discontinuity of the dotted curve. See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0079527#pone.0079527-Hudson1" target="_blank">[34]</a> for review of the concept of profile confidence intervals.</p
Variation in realized synchrony due to demographic stochasticity.
<p>Simulated prey population dynamics in a two-patch Rosenzweig-MacArthur predator-model with demographic stochasticity <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0079527#pone.0079527-Yaari1" target="_blank">[33]</a>. In each panel, red and blue lines show prey dynamics in two patches linked by dispersal of prey and predators at the same per-capita rate. The four panels show four different realizations of the model, using the same parameter values and starting from the same, initially-antisynchronous state. Because the model is stochastic, different realizations can have very different behavior, including (a) slow achievement of synchrony (after βΌ50 time units in this example), (b) rapid achievement of synchrony (after βΌ12 time units) which is subsequently maintained, (c) failure to achieve synchrony during the simulated time period, and (d) achievement of synchrony (after βΌ25 time units) which is subsequently lost. Dynamics were simulated using the SSA algorithm of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0079527#pone.0079527-Yaari1" target="_blank">[33]</a>, using the following parameter values: attack rate 0.01, handling time 3.0, predator per-capita mortality rate 0.5, predator conversion efficiency 0.4, prey intrinsic rate of increase 2.0 (β=β per-capita birth rate 3.0 - per-capita mortality rate 1.0), prey carrying capacity 1000, prey and predator per-capita dispersal rate 0.05.</p