Format: ORAL

Johana Villagra1, David Alors1, Leopoldo G. Sancho2, Claudio Inostroza-Blancheteau1

1 Catholic University of Temuco. Temuco, Chile 2 Complutense University of Madrid. Madrid, Spain

The Araucaria araucana forest is one ecosystem highly affected by climate change, global warming and fire. This conifer specie is endemic to southern South America at the Chilean and Argentinian mountain ranges, distributed from ~3724 to ~4003 S. The epiphytic lichens inhabiting this forest shows a close relationship with his phorophyte and are an important biological group increasing the biodiversity of the habitat. Some lichen functional traits like thickness of the thallus layer or state of the photosystems can vary in response to changes in light, humidity and temperature that can occur in the environment. However, it is unclear how in the scenario of global climate change (GCC) with a decrease in precipitation and an increase in temperature will affects the epiphytic lichens of A. araucana forest. Lichens are especially vulnerable to environmental conditions since they need availability of water to maintain their active metabolism. In this work we aimed to understand how lichens are adapted to the expected GCC we are studying the tolerance to desiccation of epiphytic lichens. Macrolichens collected on A. araucana bark from two different populations where compared, one located at Conguillo National Park (Andes Mountains) and the other at Nahuelbuta National Park (Coastal Mountains). We measured the photosynthetic performance of lichens after maintaining in dry atmosphere for a time period of 72 days. We found significant differences in the response of the maximum efficiency of PSII (Fv/Fm) to desiccation over time and in the anatomy of the thallus between species. The physiological response of the species compared to the anatomical responses and macroclimatic and microclimatic records are discussed.