(2014). Taxonomic diversity assessment and phylogenetic species delimitation studies Lichens were identified using appropriate identification keys for the different countries (e.g. Smith et al. 2009; Wirth et al. 2013a;
2013b), and in many cases aided by comparison with original taxonomic literature and verified voucher specimens. In several groups, species delimitation studies are conducted using multi-gene phylogenies. The moss species were determined by experts on the local flora and names are according to Hill et al. (2006) and Köckinger et al. (2013). Cyanobacteria and algae were identified by Lumacaftor in vivo light microscopy of soil samples and appropriate taxonomic keys (Geitler 1932; Komárek and Anagnostidis 1998; 2005; Ettl and Gärtner 1995). Morphology Thallus HSP inhibitor size (n = 30, independent individuals) was determined and layer thicknesses (upper cortex, photobiont layer, medulla, lower cortex (where present) were measured on freezing microtome sections (n = 300 from 30 independent thalli) for selected key lichen species. Net carbon gain A model linking 3 sets of measurements was used to calculate net carbon gain: (1) Chlorophyll fluorescence monitoring of activity (supplementary material Fig. 2c–e), at least one year of data from each site (2 preferred) is obtained by using
a chlorophyll fluorescence based device measuring the yield ((Y = Fm′−F)/Fm′, with F being the basal fluorescence and Fm′ the maximal fluorescence following a saturation pulse) of PS II (MONI-DA, Gademann Sorafenib in vitro Instruments, Würzburg). (2) CO2-exchange of BSCs in the field using a portable gas exchange fluorescence system (GFS-3000, Walz, Effeltrich), acquiring at least 14 days of continuous records from each
site. (3) The response of net CO2-exchange of BSCs to environmental factors in the lab under controlled conditions. Particular attention is given to lichenized fungal species and cyanobacteria, which are key ecological components of soil crusts. Values given in the text are mean ± standard deviation. Adaptation/acclimation/genetic uniqueness of key organisms Lichens of the same species from all four sites were sampled to test whether they show the same CO2-exchange behavior, a climate-specific acclimation and whether they have local photobiont populations. Five to ten subpopulations of selected lichen species were sampled from each site. Genetic variation is investigated by haplotype identity using DNA sequences from both mycobionts and photobionts, this data will be correlated with measurements of morphological traits such as surface area and thallus thickness, and also related to CO2-exchange data. Transplantation The following species are transplanted from every site to all other sites and will be analyzed for changes in morphology, photosynthetic performance and their photobionts after 1.5 years: P. decipiens, T. sedifolia, Peltigera rufescens, F. fulgens, F. bracteata, and Diploschistes muscorum.