DOI: 10.5061/dryad.675mr
title: Data from: Linking intra-specific trait variation to community abundance dynamics improves ecological predictability by revealing a growth-defence trade-off

description: 1.Intraspecific trait change, including altered behaviour or morphology,
 can drive temporal variation in inter-specific interactions and population
 dynamics. In turn, variation in species’ interactions and densities can
 alter the strength and direction of trait change. The resulting feedback
 between species′ traits and abundance permits a wide range of community
 dynamics that would not be expected from ecological theories purely based
 on species abundances. Despite the theoretical importance of these
 interrelated processes, unambiguous experimental evidence of how
 intraspecific trait variation modifies species interactions and population
 dynamics and how this feeds back to influence trait variation is currently
 required. 2.We investigate the role of trait-mediated demography in
 determining community dynamics and examine how ecological interactions
 influence trait change. We concurrently monitored the dynamics of
 community abundances and individual traits in an experimental microbial
 predator-prey-resource system. Using this data, we parameterized a trait
 dependent community model to identify key ecologically relevant traits and
 to link trait dynamics with those of species abundances. 3.Our results
 provide clear evidence of a feedback between trait change, demographic
 rates and species dynamics. The inclusion of trait-abundance feedbacks
 into our population model improved the predictability of ecological
 dynamics from r-squared of 34% to 57% and confirmed theoretical
 expectations of density dependent population growth and species
 interactions in the system. 4.Additionally, our model revealed that the
 feedbacks were underpinned by a trade-off between population growth and
 anti-predatory defence. High predator abundance was linked to a reduction
 in prey body size. This prey size decrease was associated with a reduction
 in its rate of consumption by predators and a decrease in its resource
 consumption. 5.Modelling trait-abundance feedbacks allowed us to pinpoint
 the underlying life history trade-off which links trait and abundance
 dynamics. These results show that accounting for trait-abundance feedbacks
 has the potential to improve understanding and predictability of
 ecological dynamics.
description: Predator-prey-resource
 trait-abundance feedback datasetCommunity abundance and
 trait dynamics in a tri-trophic predator-prey-resource system, consisting
 of a bacteria resource, Serratia marcescens, an intermediate bactiverous
 ciliate Colpidium striatum (referred to as the prey), and a top
 predator, Stentor coeruleus. The experiments were conducted in
 experimental microcosms at 20°C with a 16: 8 light-dark photoperiod. The
 BEMOVI R package was used to automate the sampling/measurement of traits
 and abundances (Pennekamp, Frank, Nicolas Schtickzelle, and Owen L.
 Petchey. 2015. “Bemovi, Software for Extracting BEhaviour and MOrphology
 from VIdeos, illustrated with anlyses of microbes”, Ecology &
 Evolution, June 2015. DOI: 10.1002/ece3.1529).The resulting data has the
 following columns:1)"row_id" = a unique number for each row, 2)
 "incubator" = indicator of which incubator the data comes from,
 3) "spp" = the species combination in the microcosm (c=prey
 & resource only, sc= predator, prey & resource), 4)
 "replicate"=the replicate, 5) "time"= time in days, 6)
 "temperature"= temperature in degrees, 7)
 "N_pred_dens.ml"= Number of predators per ml, 8)
 "N_prey_dens.ml"=Number of prey per ml, 9)
 "N_resource_dens.ml"= Number of resource per ml, 10)
 "sqrt_prey_area"= square root of prey area, 11)
 "prop_secondary_resource"=proportion of bacteria in the
 secondary resource class. Linking intra-specific trait
 variation to community abundance
 dynamics.csv