Population responses to environmental change in a tropical ant: the interaction of spatial and temporal dynamics

PLoS One. 2014 May 19;9(5):e97809. doi: 10.1371/journal.pone.0097809. eCollection 2014.

Abstract

Spatial structure can have a profound, but often underappreciated, effect on the temporal dynamics of ecosystems. Here we report on a counterintuitive increase in the population of a tree-nesting ant, Azteca sericeasur, in response to a drastic reduction in the number of potential nesting sites. This surprising result is comprehensible when viewed in the context of the self-organized spatial dynamics of the ants and their effect on the ants' dispersal-limited natural enemies. Approximately 30% of the trees in the study site, a coffee agroecosystem in southern Mexico, were pruned or felled over a two-year period, and yet the abundance of the ant nests more than doubled over the seven-year study. Throughout the transition, the spatial distribution of the ants maintained a power-law distribution - a signal of spatial self organization - but the local clustering of the nests was reduced post-pruning. A cellular automata model incorporating the changed spatial structure of the ants and the resulting partial escape from antagonists reproduced the observed increase in abundance, highlighting how self-organized spatial dynamics can profoundly influence the responses of ecosystems to perturbations.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animal Distribution*
  • Animals
  • Ants / physiology*
  • Computer Simulation
  • Environment*
  • Mexico
  • Models, Biological
  • Nesting Behavior / physiology*
  • Population Dynamics
  • Spatial Behavior / physiology*
  • Trees
  • Tropical Climate

Grants and funding

NSF grant to J.V. and I.P.: DEB-0349388; NSF grant to S.P.: DEB-1020096; Graham Environmental Sustainability Institute Doctoral Fellowship to D.J. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.