Temperature effects on prey and basal resources exceed that of predators in an experimental community

TY - JOUR

T1 - Temperature effects on prey and basal resources exceed that of predators in an experimental community

AU - Thakur, Madhav P.

AU - Griffin, John N.

AU - Künne, Tom

AU - Dunker, Susanne

AU - Fanesi, Andrea

AU - Eisenhauer, Nico

N1 - 6671, TE; Data Archiving: data archived at Dryad

PY - 2018/12/1

Y1 - 2018/12/1

N2 - Abstract Climate warming alters the structure of ecological communities by modifying species interactions at different trophic levels. Yet, the consequences of warming-led modifications in biotic interactions at higher trophic levels on lower trophic groups are lesser known. Here, we test the effects of multiple predator species on prey population size and traits and subsequent effects on basal resources along an experimental temperature gradient (12?15°C, 17?20°C, and 22?25°C). We experimentally assembled food web modules with two congeneric predatory mites (Hypoaspis miles and Hypoaspis aculeifer) and two Collembola prey species (Folsomia candida and Proisotoma minuta) on a litter and yeast mixture as the basal resources. We hypothesized that warming would modify interactions within and between predator species, and that these alterations would cascade to basal resources via changes in the density and traits (body size and lipid: protein ratio) of the prey species. The presence of congeners constrained the growth of the predatory species independent of warming despite warming increased predator density in their respective monocultures. We found that warming effects on both prey and basal resources were greater than the effects of predator communities. Our results further showed opposite effects of warming on predator (increase) and prey densities (decrease), indicating a warming-induced trophic mismatch, which are likely to alter food web structures. We highlight that warmer environments can restructure food webs by its direct effects on lower trophic groups even without modifying top-down effects.

AB - Abstract Climate warming alters the structure of ecological communities by modifying species interactions at different trophic levels. Yet, the consequences of warming-led modifications in biotic interactions at higher trophic levels on lower trophic groups are lesser known. Here, we test the effects of multiple predator species on prey population size and traits and subsequent effects on basal resources along an experimental temperature gradient (12?15°C, 17?20°C, and 22?25°C). We experimentally assembled food web modules with two congeneric predatory mites (Hypoaspis miles and Hypoaspis aculeifer) and two Collembola prey species (Folsomia candida and Proisotoma minuta) on a litter and yeast mixture as the basal resources. We hypothesized that warming would modify interactions within and between predator species, and that these alterations would cascade to basal resources via changes in the density and traits (body size and lipid: protein ratio) of the prey species. The presence of congeners constrained the growth of the predatory species independent of warming despite warming increased predator density in their respective monocultures. We found that warming effects on both prey and basal resources were greater than the effects of predator communities. Our results further showed opposite effects of warming on predator (increase) and prey densities (decrease), indicating a warming-induced trophic mismatch, which are likely to alter food web structures. We highlight that warmer environments can restructure food webs by its direct effects on lower trophic groups even without modifying top-down effects.

KW - international

KW - litter decomposition

KW - microbial biomass

KW - multiple predator effects

KW - trait-mediated interactions

KW - trophic cascade

KW - trophic mismatch

KW - ectotherms

UR - https://doi.org/10.5061/dryad.4d15b08

U2 - 10.1002/ece3.4695

DO - 10.1002/ece3.4695

M3 - Article

SN - 2045-7758

VL - 8

SP - 12670

EP - 12680

JO - Ecology and Evolution

JF - Ecology and Evolution

IS - 24

ER -