CSR ecological strategies and plant mating systems: outcrossing increases with competitiveness but stress-tolerance is related to mixed mating
Résumé
A number of plant traits influence the success of fertilization and reproduction in plants. Collectively these traits represent
ecological syndromes that are of evolutionary significance. However, while an association between mating system and colonizing
ability has been proposed, the existence of a broader relationship between mating system and a species’ position in
ecological succession has not been extensively investigated. Grime’s CSR theory stresses that an ecological succession can
involve changes from colonizing to either competitive or stress-tolerant strategies. How distinct dimensions of competitiveness
and stress tolerance covary with mating systems has still not been considered. We designed a comparative approach to
evaluate the link between mating system, life form and CSR strategies for 1996 herbaceous and woody species. We found
that CSR strategies are significantly related to mating systems. Ruderal species – colonizers in early succession – were
mostly selfers while more competitive species were more often outcrossers. On the other hand, greater physiological stress
tolerance was associated with mixed mating systems. Outcrossing is classically expected to be advantageous for most life
history strategies other than colonizers, but we suggest that reproductive assurance can counterbalance this effect in stressful
environments where populations are sparse and pollinators are rare. Therefore, our results emphasize that competition and
abiotic stresses are not equivalent selective pressures on the evolution of mating systems. Finally, we found plant life span to
convey additional information on mating system variation, supporting its role for mating system evolution. These findings
encourage further investigation of the evolutionary role of ecological strategies as syndromes of traits and suggest that the
emergence of large databases of plant traits will help address the major evolutionary hypotheses on such syndromes.
Origine | Fichiers produits par l'(les) auteur(s) |
---|
Loading...