Effect of stressors on the carrying capacity of spatially distributed metapopulations

Bo Zhang, Donald L. Deangelis, Wei Ming Ni, Yuanshi Wang, Lu Zhai, Alex Kula, Shuang Xu, J. David Van Dyken

Research output: Contribution to journalArticlepeer-review

6 Scopus citations

Abstract

Stressors such as antibiotics, herbicides, and pollutants are becoming increasingly common in the environment. The effects of stressors on populations are typically studied in homogeneous, nonspatial settings. However, most populations in nature are spatially distributed over environmentally heterogeneous landscapes with spatially restricted dispersal. Little is known about the effects of stressors in these more realistic settings. Here, we combine laboratory experiments with novel mathematical theory to rigorously investigate how a stressor’s physiological effect and spatial distribution interact with dispersal to influence population dynamics. We prove mathematically that if a stressor increases the death rate and/or simultaneously decreases the population growth rate and yield, a homogeneous distribution of the stressor leads to a lower total population size than if the same amount of the stressor was heterogeneously distributed. We experimentally test this prediction on spatially distributed populations of budding yeast (Saccharomyces cerevisiae). We find that the antibiotic cycloheximide increases the yeast death rate but reduces the growth rate and yield. Consistent with our mathematical predictions, we observe that a homogeneous spatial distribution of cycloheximide minimizes the total equilibrium size of experimental metapopulations, with the magnitude of the effect depending predictably on the dispersal rate and the geographic pattern of antibiotic heterogeneity. Our study has implications for assessing the population risk posed by pollutants, antibiotics, and global change and for the rational design of strategies for employing toxins to control pathogens and pests.

Original languageEnglish (US)
Pages (from-to)E46-E60
JournalAmerican Naturalist
Volume196
Issue number2
DOIs
StatePublished - Aug 1 2020

Keywords

  • Consumer-resource model
  • Laboratory experiments
  • Movement ecology
  • Patchy environment
  • Spatial ecology
  • Spatially heterogeneous parameters

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics

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