Allelochemicals of Pinus halepensis as Drivers of Biodiversity in Mediterranean Open Mosaic Habitats During the Colonization Stage of Secondary Succession

Catherine Fernandez*, Mathieu Santonja, Raphael Gros, Yogan Monnier, Mathilde Chomel, Virginie Baldy, Anne Bousquet-Melou

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

48 Citations (Scopus)

Abstract

The Mediterranean region is recognized as a global biodiversity hotspot. However, over the last 50 years or so, the cessation of traditional farming has given way to strong afforestation at the expense of open habitats. Pinus halepensis Miller, known to synthesize a wide range of secondary metabolites, is a pioneer expansionist species colonizing abandoned agricultural land that present high species richness. Here, laboratory bioassays were used to study the potential impact of P. halepensis on plant diversity through allelopathy, and the role of microorganisms in these interactions. Germination and growth of 12 target species naturally present in fallow farmlands were tested according to concentration of aqueous extracts obtained from shoots of young pines (aged about 5 years), with or without the presence of soil microorganisms (autoclaved or natural soil). Under the highest concentrations and autoclaved soil, more than 80 % of target species were germination and/or growth-inhibited, and only two species were non-sensitive. Under more natural conditions (lower extracts concentrations and natural soil with microorganisms), only 50 % of species were still inhibited, one was non-sensitive, and five were stimulated. Thus, microorganisms alter the expression of allelochemicals released into the ecosystem, which highlights their key role in chemical plant-plant interactions. The results of allelopathic experiments conducted in the lab are consistent with the community patterns observed in the field. These findings suggest that allelopathy is likely to shape vegetation composition and participate to the control of biodiversity in Mediterranean open mosaic habitats.

Original languageEnglish
Pages (from-to)298-311
Number of pages14
JournalJournal of Chemical Ecology
Volume39
Issue number2
Early online date18 Jan 2013
DOIs
Publication statusPublished - Feb 2013

Keywords

  • Allelopathy
  • Plant-plant interaction
  • Community structure
  • Mediterranean biodiversity
  • Secondary succession
  • Aleppo pine
  • Soil microorganisms
  • Bacterial-colonization
  • Phenolic-compounds
  • Seed-germination
  • Soil
  • Plants
  • Needles
  • Metabolites
  • Diversity
  • Forestry

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