Herbivore metabolism and stoichiometry each constrain herbivory at different organizational scales across ecosystems.
Plant-herbivore interactions mediate the trophic structure of ecosystems. We use a comprehensive data set extracted from the literature to test the relative explanatory power of two contrasting bodies of ecological theory, the metabolic theory of ecology (MTE) and ecological stoichiometry (ES), for per-capita and population-level rates of herbivory across ecosystems. We found that ambient temperature and herbivore body size (MTE) as well as stoichiometric mismatch (ES) both constrained herbivory, but at different scales of biological organization. Herbivore body size, which varied over 11 orders of magnitude, was the primary factor explaining variation in per-capita rates of herbivory. Stoichiometric mismatch explained more variation in population-level herbivory rates and also in per-capita rates when we examined data from within functionally similar trophic groups (e.g. zooplankton). Thus, predictions from metabolic and stoichiometric theories offer complementary explanations for patterns of herbivory that operate at different scales of biological organization.
Hillebrand
Helmut
H
Institute for Chemistry and Biology of the Marine Environment, Carl-von-Ossietzky-University Oldenburg, Schleusenstrasse 1, D-26385 Wilhelmshaven, Germany. hillebrand@icbm.de
Borer
Elizabeth T
ET
Bracken
Matthew E S
ME
Cardinale
Bradley J
BJ
Cebrian
Just
J
Cleland
Elsa E
EE
Elser
James J
JJ
Gruner
Daniel S
DS
Harpole
W Stanley
WS
Ngai
Jacqueline T
JT
Sandin
Stuart
S
Seabloom
Eric W
EW
Shurin
Jonathan B
JB
Smith
Jennifer E
JE
Smith
Melinda D
MD
D000818:Animals; D049628:Body Size; D001831:Body Temperature; D004435:Eating; D017753:Ecosystem; D004734:Energy Metabolism; D005247:Feeding Behavior; D020387:Food Chain; D007448:Invertebrates / Q000378:metabolism / Q000502:physiology; D008954:Models, Biological; D010788:Photosynthesis; D063245:Plant Development; D010944:Plants / Q000378:metabolism; D011156:Population Density; D011157:Population Dynamics; D015048:Zooplankton / Q000378:metabolism