DOI: 10.5061/dryad.bf4rk74
title: Data from: An experimental test of the effects of dispersal and the paradox of enrichment on metapopulation persistence

description: Many species exhibit high-amplitude, extinction-prone cycles, for instance
 due to resource enrichment (called the paradox of enrichment). How do such
 species manage to persist? One possibility is metapopulation dynamics, but
 it is unclear if these can mitigate the paradox of enrichment. The paradox
 of enrichment might increase local population extinction rates, and might
 also increase the spatial synchrony of population fluctuations because
 population cycles are easily synchronized by even low rates of dispersal.
 Spatially-synchronous population fluctuations would leave no scope for
 rescue effects, and spatially-synchronous local extinctions would leave no
 source for recolonization. We conducted a protist microcosm experiment to
 test how dispersal and enrichment affect the persistence of predator-prey
 metapopulations by altering spatial synchrony. We assembled 54, 4-patch
 metapopulations of the protist predator Euplotes patella and its protist
 prey Tetrahymena pyriformis. Each metapopulation experienced one of nine
 dispersal rates, crossed with one of 6 enrichment levels. We tested the
 effects of enrichment and dispersal on predator-prey cycle amplitude,
 predator population extinction risk, spatial synchrony of predator
 population fluctuations, and predator metapopulation persistence time.
 Enrichment increased predator-prey cycle amplitude but had no detectable
 effect on population extinction risk. Dispersal had no effect on
 predator-prey cycle amplitude. Spatial synchrony increased with enrichment
 and dispersal. Metapopulation persistence decreased with enrichment and
 spatial synchrony. We conclude that increasing enrichment reduced
 metapopulation persistence primarily by increasing spatial synchrony of
 local extinctions, rather than by increasing their frequency. These
 results highlight the importance of synchrony-preventing mechanisms for
 metapopulation persistence.
description: raw data from Laan and
 Fox Oikos ms on enrichment and metapopulation
 persistenceRaw data for the Oikos
 paper by Erin Laan and Jeremy W. Fox on metapopulation enrichment and
 persistence. Data are from a laboratory microcosm experiment in which the
 protist predator Euplotes patella and its protist prey Tetrahymena
 pyriformis were grown in metapopulations (arrays of four culture vessels
 interlinked by dispersal) subjected to different enrichment levels and
 rates of dispersal. Predator abundance and prey presence/absence were
 tracked over time. Column headings are as follows: Day is the day of the
 sample, with day 0 being the day predators were added to the experiment.
 metapop is an identifying number for each metapopulation. disp.rate is the
 dispersal rate, in ml of culture medium removed from each 40 ml culture
 vessel and dispersed randomly over the entire metapopulation during each
 dispersal event. pp.g.l is the enrichment level of the metapopulation, in
 g of Protozoan Pellets (commercially-purchased pellets of crushed dried
 plant matter, which support the growth of the bacteria on which the prey
 feed) per liter of culture medium. Eupl.[number] is the density of
 Euplotes (number per ml) in each of the four culture vessels comprising
 the metapopulation, as indicated by the number. Tet.pres[number] is the
 presence (1) or absence (0) of Tetrahymena in each of the four culture
 vessels comprising the metapopulation, as indicated by the
 number.summer 2017 metapop expt data
 for dryad.csv