Carrying capacity in a heterogeneous environment with habitat connectivity

Bo Zhang, Alex Kula, Keenan M.L. Mack, Lu Zhai, Arrix L. Ryce, Wei Ming Ni, Donald L. DeAngelis, J.  David Van Dyken

Research output: Contribution to journalLetter

19 Scopus citations

Abstract

A large body of theory predicts that populations diffusing in heterogeneous environments reach higher total size than if non-diffusing, and, paradoxically, higher size than in a corresponding homogeneous environment. However, this theory and its assumptions have not been rigorously tested. Here, we extended previous theory to include exploitable resources, proving qualitatively novel results, which we tested experimentally using spatially diffusing laboratory populations of yeast. Consistent with previous theory, we predicted and experimentally observed that spatial diffusion increased total equilibrium population abundance in heterogeneous environments, with the effect size depending on the relationship between r and K. Refuting previous theory, however, we discovered that homogeneously distributed resources support higher total carrying capacity than heterogeneously distributed resources, even with species diffusion. Our results provide rigorous experimental tests of new and old theory, demonstrating how the traditional notion of carrying capacity is ambiguous for populations diffusing in spatially heterogeneous environments.

Original languageEnglish (US)
Pages (from-to)1118-1128
Number of pages11
JournalEcology Letters
Volume20
Issue number9
DOIs
StatePublished - Sep 2017

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Keywords

  • Carrying capacity
  • consumer–resource model
  • dispersal experiment
  • environmental stressor
  • heterogeneous resource distribution
  • r-K relationship
  • spatially distributed population

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics

Cite this

Zhang, B., Kula, A., Mack, K. M. L., Zhai, L., Ryce, A. L., Ni, W. M., DeAngelis, D. L., & Van Dyken, J. D. (2017). Carrying capacity in a heterogeneous environment with habitat connectivity. Ecology Letters, 20(9), 1118-1128. https://doi.org/10.1111/ele.12807