DOI: 10.5061/dryad.v9s4mw6x8
title: Temperature and nutrient availability alter consequences of phenological shifts in predatory-prey communities

description: While there is mounting evidence indicating that the relative timing of
 predator and prey phenologies shapes the outcome of trophic interactions,
 we still lack a comprehensive understanding of how important the
 environmental context (e.g. abiotic conditions) is for shaping this
 relationship. Environmental conditions not only frequently drive shifts in
 phenologies, but they can also affect the very same processes that mediate
 the effects of phenological shifts on species interactions. Thus,
 identifying how environmental conditions shape the effects of phenological
 shifts is key to predict community dynamics across a heterogenous
 landscape and how they will change with ongoing climate change in the
 future. Here I tested how environmental conditions shape effects of
 phenological shifts by experimentally manipulating temperature, nutrient
 availability, and relative phenologies in two predator-prey freshwater
 systems (mole salamander- bronze frog vs dragonfly larvae-leopard frog).
 This allowed me to (1) isolate the effect of phenological shifts and
 different environmental conditions, (2) determine how they interact, and
 (3) how consistent these patterns are across different species and
 environments. I found that delaying prey arrival dramatically increased
 predation rates, but these effects were contingent on environmental
 conditions and predator system. While both nutrient addition and warming
 significantly enhanced the effect of arrival time, their effect was
 qualitatively different: Nutrient addition enhanced the positive effect of
 early arrival while warming enhanced the negative effect of arriving late.
 Predator responses varied qualitatively across predator-prey systems. Only
 in the system with strong gape-limitation were predators (salamanders)
 significantly affected by prey arrival time and this effect varied with
 environmental context. Correlations between predator and prey demographic
 rates suggest that this was driven by shifts in initial predator-prey size
 ratios and a positive feedback between size-specific predation rates and
 predator growth rates. These results highlight the importance of
 accounting for temporal and spatial correlation of local environmental
 conditions and gape-limitation in predator-prey systems when predicting
 the effects of phenological shifts and climate change on predator-prey
 systems.
description: The data includes two experiments conducted in mesocosms in 2013
 and 2015. The first experiment was conducted with dragonfly predators Anax
 junis and tadpole prey Rana sphenocephala, and the second with salamander
 Ambystoma talpoideum and tadpole from Rana clamitans. The experiments had
 the same experimental design, manipulating prey arrival (0 delay, 10 days
 or 20 days after predator addition), crossed fully factorially with 2
 warming (ambient vs +4.5C) and nutrient additions (ambient vs added)
 resulting in 12 treatments. Experiments lasted 189 and 100 days
 respectively and were monitored daily. Collected data includes: predator
 and prey development time (from addition to experiment to metamorphosis)
 and mortality (number of survivors), salamander mass and prey mass at
 metamorphosis, periphyton abundance (measures as clorophyll a),
 temperature data from temperature loggers (set at 30 minute intervals),
 predator sizes at each prey addition, and prey size after ~35-38
 days.  The corresponding R code is also provide as
 markdown document.
description: All the information about data is given in corresponding Markdown
 document. Note that the data includes all raw data, and has not been
 "cleaned" yet for outlier etc. This was done in the R code and
 indicated in the markdown files (e.g. removal of clear data entry errors
 in tadpole mass). Date is listed in
 DataMetafile_ReadMe.docx