Freezing resistance varies within the growing season and with elevation in high-Andean species of central Chile.
Predicted increases in the length of the growing season as a result of climate change may more frequently expose high-elevation plants to severe frosts. Understanding the ability of these species to resist frosts during the growing season is essential for predicting how species may respond to changes in temperature regimes. Here, we assessed the freezing resistance of 24 species from the central Chilean Andes by determining their low temperature damage (LT(50)), ice nucleation temperature (NT), freezing point (FP) and freezing resistance mechanism (i.e. avoidance or tolerance). The Andean species were found to resist frosts from -8.2 to -19.5 degrees C during the growing season, and freezing tolerance was the most common resistance mechanism. Freezing resistance (LT(50)) varied within the growing season, decreasing towards the end of this period in most of the studied species. However, the FP showed the opposite trend. LT(50) increased with elevation, whilst FP was lower in plants from lower elevations, especially late in the growing season. Andean species have the potential to withstand severe freezing conditions during the growing season, and the aridity of this high-elevation environment seems to play an important role in determining this high freezing resistance.
Sierra-Almeida
Angela
A
ECOBIOSIS, Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile.|Instituto de Ecología y Biodiversidad (IEB), Casilla 653, Santiago, Chile.
Cavieres
Lohengrin A
LA
ECOBIOSIS, Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile.|Instituto de Ecología y Biodiversidad (IEB), Casilla 653, Santiago, Chile.
Bravo
León A
LA
Laboratorio de Fisiología Vegetal, Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile.
D000222:Adaptation, Physiological; D000531:Altitude; D002677:Chile; D003080:Cold Temperature; D017753:Ecosystem; D005615:Freezing; D017752:Greenhouse Effect; D063245:Plant Development; D018521:Plant Physiological Phenomena