Actas de congresos
Tolerance of an invasive plant in a copper saturated environment: Local adaptation as an evolutionary response?
Fecha
2015Institución
Resumen
Human disturbance associated with mining activity can lead to accumulation of certain metals in
the environment, and these metals can limit plant growth and survival. Faced with these new
environmental conditions, the persistence of plant populations could be due to phenotypic
plasticity or local adaptation. Invasive plants might evolve rapidly when exposed to stressful or
changing environments; this feature could allow invasive Eschscholzia californica to colonize
highly polluted areas in Chile, such as sites near mining activities. It is unknown whether
E.californica’s persistence at sites poor in nutrients or with high concentrations of metals is due
to local adaptation or simply due to an inherent ability to tolerate these conditions. To answer
this question, we conducted reciprocal transplant field and laboratory experiments (common
garden) to determine levels of tolerance to heavy metals such as copper. The results of common
garden experiments indicated a lack of tolerance to copper, regardless the source population; this
effect was greatest at extreme levels of copper. In the reciprocal transplant experiment, the
contaminated site was stressful for both populations; in the control site, seedlings belonging to
the contaminated site improved their performance compared to growth at their origin site. Our
results indicate lack of local adaptation to copper and low phenotypic plasticity; there wasn’t a
change in phenotype when comparing populations exposed to varying degrees of stress, therefore
additional ecological and physiological studies are needed to explain the persistence of
E.californica on copper-contaminated soils.