Phylogenetic grouping, curvature and metabolic scaling in terrestrial invertebrates.

J.F. Blumenbach Institute of Zoology and Anthropology, Berliner Str. 28, 37073 Göttingen, Germany.
Ecology Letters (Impact Factor: 13.04). 07/2011; 14(10):993-1000. DOI: 10.1111/j.1461-0248.2011.01660.x
Source: PubMed

ABSTRACT For more than a century, the scaling of animal metabolic rates with individual body masses and environmental temperature has predominantly been described by power-law and exponential relationships respectively. Many theories have been proposed to explain these scaling relationships, but were challenged by empirically documented curvatures on double-logarithmic scales. In the present study, we present a novel data set comprising 3661 terrestrial (mainly soil) invertebrate respiration rates from 192 independent sources across a wide range in body masses, environmental temperatures and phylogenetic groups. Although our analyses documented power-law and exponential scaling with body masses and temperature, respectively, polynomial models identified curved deviations. Interestingly, complex scaling models accounting for phylogenetic groups were able to remove curvatures except for a negative curvature at the highest temperatures (>30 °C) indicating metabolic down regulation. This might indicate that the tremendous differences in invertebrate body architectures, ecology and physiology may cause severely different metabolic scaling processes.

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Roswitha Ehnes