LIVE: Lichen holobiome diversity along climatic gradients

Applicant: Ulrike Ruprecht Co-author: Robert R. Junker Cooperationpartner: Wolfgang Trutschnig/ IDA Lab Salzburg Organisms inhabiting climatically extreme regions are sensitive to changes in environmental conditions. Current climate warming, for instance, forces cold-adapted lichens to shift their natural geographic distributions, which may cause changes in the interactions between fungi, algae, and bacteria that form the lichen holobiont. Accordingly, lichens are ideal model systems to study the effects of climate warming on species interactions and diversity. Lichen form primarily a symbiosis of a fungus (mycobiont) together with an algal partner (photobiont). In addition, species-rich bacterial communities and other associated fungi and algae are part of the whole organism, which is called a lichen holobiom. The composition of the participating partners in the lichen holobiom is suggested to change along different climatic gradients. The major aim of the project is to investigate how the diverse lichen community responds to a latitudinal gradient in the Southern Polar Regions (South America, Maritime and Continental Antarctic) and along an elevational gradient in the high mountainous areas in the Austrian Alps. These insights will help to assess the vulnerability of these extreme habitats towards climate warming. The composition of the participants in the lichen holobiom will be assessed by using state-of- the-art molecular methods (next generation sequencing, NGS). These data will be analysed with network statistics and niche models. This study will provide entirely new insights into the varying compositions of these species - rich organisms. The use of community-ecological methods and the identification of the current climatic requirements of the individual lichens will help to understand the factors determining the relationships between species diversity, composition and distribution along climatic gradients.