Belowground Herbivory: The Adaptive Geometry of Geomyid Burrows
In this paper, I mathematically model the energy cost-benefit relationships for gophers burrowing in habitats that feature various BEDPs. These models are then analyzed to determine the geometric characteristics of the optimal burrow, given the above premise. I first examine the simplest model in which BEDP is uniform both horizontally and vertically. This analysis leads to model 2, in which a linear, unimodal distribution is used to describe, with increased realism, the vertical component of BEDP. These same models are then examined under an alternative premise: that gophers attempt to maximize net gain per unit volume of soil excavated. Insofar as the modeled BEDPs mimic real ones, the conclusions derived from the analyses can be considered predictions for testing the hypothesis that the geometry of pocket gopher burrows is adaptive, relative to maximizing energy income. Data from the literature are then used to compare actual with predicted features of geomyid burrow systems.
Andersen, D.C. (1982). Belowground herbivory: The adaptive geometry of geomyid burrows. American Naturalist 119(1): 18-28.