Legacy of historic ozone exposure on plant community and food web structure

PLoS One. 2017 Aug 10;12(8):e0182796. doi: 10.1371/journal.pone.0182796. eCollection 2017.

Abstract

Information on whole community responses is needed to predict direction and magnitude of changes in plant and animal abundance under global changes. This study quantifies the effect of past ozone exposure on a weed community structure and arthropod colonization. We used the soil seed bank resulting from a long-term ozone exposure to reestablish the plant community under a new low-pollution environment. Two separate experiments using the same original soil seed bank were conducted. Plant and arthropod richness and species abundance was assessed during two years. We predicted that exposure to episodic high concentrations of ozone during a series of growing cycles would result in plant assemblies with lower diversity (lower species richness and higher dominance), due to an increase in dominance of the stress tolerant species and the elimination of the ozone-sensitive species. As a consequence, arthropod-plant interactions would also be changed. Species richness of the recruited plant communities from different exposure histories was similar (≈ 15). However, the relative abundance of the dominant species varied according to history of exposure, with two annual species dominating ozone enriched plots (90 ppb: Spergula arvensis, and 120 ppb: Calandrinia ciliata). Being consistent both years, the proportion of carnivore species was significantly higher in plots with history of higher ozone concentration (≈3.4 and ≈7.7 fold higher in 90 ppb and 120 ppb plots, respectively). Our study provides evidence that, past history of pollution might be as relevant as management practices in structuring agroecosystems, since we show that an increase in tropospheric ozone may influence biotic communities even years after the exposure.

MeSH terms

  • Air Pollutants / toxicity*
  • Animals
  • Argentina
  • Arthropods / physiology
  • Atmosphere
  • Biodiversity
  • Food Chain
  • Ozone / toxicity*
  • Plant Dispersal
  • Plant Weeds / drug effects*
  • Plant Weeds / growth & development
  • Plant Weeds / parasitology
  • Population Dynamics

Substances

  • Air Pollutants
  • Ozone

Grants and funding

This study was funded by the Universidad de Buenos Aires, UBACyT 2014-2017 (grant No. 20020130100030BA) to MAMG and the Agencia Nacional de Investigaciones Científicas y Técnicas, PICT 2355 to MAMG. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.