Relationships between abiotic environment, plant functional traits, and animal body size at Mount Kilimanjaro, Tanzania.
The effect-response framework states that plant functional traits link the abiotic environment to ecosystem functioning. One ecosystem property is the body size of the animals living in the system, which is assumed to depend on temperature or resource availability, among others. For primary consumers, resource availability may directly be related to plant traits, while for secondary consumers the relationship is indirect. We used plant traits to describe resource availability along an elevational gradient on Mount Kilimanjaro, Tanzania. Using structural equation models, we determined the response of plant traits to changes in precipitation, temperature and disturbance with and assessed whether abiotic conditions or community-weighted means of plant traits are stronger predictors of the mean size of bees, moths, frugivorous birds, and insectivorous birds. Traits indicating tissue density and nutrient content strongly responded to variations in precipitation, temperature and disturbance. They had direct effects on pollination and fruit traits. However, the average body sizes of the animal groups considered could only be explained by temperature and habitat structure, not by plant traits. Our results demonstrate a strong link between traits and the abiotic environment, but suggest that temperature is the most relevant predictor of mean animal body size. Community-weighted means of plant traits and body sizes appear unsuitable to capture the complexity of plant-animal interactions.
Department of Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany.
David
http://orcid.org/0000-0003-1747-1506
D
Schellenberger Costa
Department of Animal Ecology and Tropical Biology, University of Würzburg, Würzburg, Germany.
Alice
A
Classen
Senckenberg Gesellschaft für Naturforschung, Biodiversity and Climate Research Center, Frankfurt, Germany.
Stefan
S
Ferger
Institute of Experimental Ecology, University of Ulm, Ulm, Germany.
Maria
M
Helbig-Bonitz
Department of Animal Ecology and Tropical Biology, University of Würzburg, Würzburg, Germany.
Marcell
M
Peters
Senckenberg Gesellschaft für Naturforschung, Biodiversity and Climate Research Center, Frankfurt, Germany.|Institute for Ecology, Evolution & Diversity, Goethe University Frankfurt, Frankfurt (Main), Germany.
Katrin
K
Böhning-Gaese
Department of Animal Ecology and Tropical Biology, University of Würzburg, Würzburg, Germany.
Ingolf
I
Steffan-Dewenter
Department of Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany.
Michael
M
Kleyer
D000818:Animals; D001516:Bees / Q000033:anatomy & histology*; D001717:Birds / Q000033:anatomy & histology*; D049628:Body Size; D004777:Environment; D008962:Models, Theoretical; D009036:Moths / Q000033:anatomy & histology*; D018521:Plant Physiological Phenomena; D013636:Tanzania