title: Three energy variables predict ant abundance at a geographical scale.
abstract: Energy theory posits three processes that link local abundance of ectotherms to geographical gradients in temperature. A survey of 49 New World habitats found a two order of magnitude span in the abundance (nests m(-2)) of ground nesting ants (Formicidae). Abundance increased with net primary productivity (r2=0.55), a measure of the baseline supply of harvestable energy. Abundance further increased with mean temperature (r2=0.056), a constraint on foraging activity for this thermophilic taxon. Finally for a given mean temperature, ants were more abundant in seasonal sites with longer, colder winters (r2 = 0.082) that help ectotherm taxa sequester harvested energy in non-productive months. All three variables are currently changing on a global scale. All should be useful in predicting biotic responses to climate change.
authors.affiliation: Department of Zoology, University of Oklahoma, Norman 73019-0235, USA. mkaspari@ou.edu
authors.forename: M
authors.initials: M
authors.lastname: Kaspari
authors.forename: L
authors.initials: L
authors.lastname: Alonso
authors.forename: S
authors.initials: S
authors.lastname: O'Donnell
mesh_terms: D000818:Animals; D001000:Ants / Q000502:physiology*; D017753:Ecosystem; D004734:Energy Metabolism; D011156:Population Density; D013696:Temperature