Life history strategy ofLepraria borealisat an Antarctic inland site, Coal Nunatak

Abstract

Coal Nunatak is an ice-free inland nunatak located on southern Alexander Island, adjacent to the west coast of the Antarctic Peninsula. Situated close to the Antarctic continent, it is characterized by harsh environmental conditions. Macroscopic colonization is restricted to micro-niches offering suitable conditions for a small number of lichens and mosses. The extreme environmental conditions place particular pressures on colonizers. Lepraria borealis is the dominant crustose lichen species present on Coal Nunatak, and shows distinctive features in its life history strategy, in particular expressing unusually low selectivity of the mycobiont towards potential photobionts. To assess selectivity, we measured algal DNA sequence polymorphism in a region of 480-660 bp of the nuclear internal transcribed spacer region of ribosomal DNA. We identified three different photobiont species, belonging to two different genera. We interpret this strategy as being advantageous in facilitating the colonization and community dominance of L. borealis under the isolation and extreme environmental conditions of Coal Nunatak.

The complexity of symbiotic interactions influences the ecological amplitude of the host: A case study inStereocaulon(lichenized Ascomycota)

“…Indeed, a wide range of Trebouxia lineages are phycobionts of species belonging to various lichen genera, for example, Protoparmelia , Rhizoplaca , Tephromela, Xanthoparmelia, Xanthoria and Xanthomendoza (Leavitt et al., , ; Muggia et al., ; Muggia, Leavitt, & Barreno, in press; Nyati et al., ), and high infrageneric diversity of Asterochloris phycobionts has also been observed in species of Cladonia (Bačkor et al., ; Beiggi & Piercey‐Normore, ; Piercey‐Normore & DePriest, ; Škaloud & Peksa, ; Yahr et al., ) and Lepraria (Nelsen & Gargas, , ; Peksa & Škaloud, ; Škaloud & Peksa, ). It is an interesting fact that only a few other lichens, which have crustose growth and (generally) a poorly developed cortex (Helms, ; Thüs et al., ), are known to build their thalli with phycobionts belonging to different Trebouxiophycean genera ( Lepraria borealis , Engelen, Convey, & Ott, ; Micarea , Yahr et al., ; Bagliettoa and Verrucaria nigrescens , Thüs et al., ; Voytsekhovich & Beck, ; Diploschistes muscorum , Wedin et al., ). In contrast, the Stereocaulon species considered in this study have complex dimorphic thalli and a well‐developed cortex (crustose species of Stereocaulon were not included).…”

“…The distribution of this species is concentrated in the Mediterranean region (Moya et al., ). It is not clear whether Asterochloris distribution is restricted by low temperatures or if the reduced amount of liquid water prevents its distribution in polar regions (Engelen et al., ; Park et al., ). An example of the joint influence of temperature and humidity is as follows: in samples from Alaska and Greenland, at very low temperatures (year mean <−5°C), Asterochloris phycobionts tolerate very low precipitation (as low as 239 mm/year in total).…”

Lichen myco- and photobiont diversity and their relationships at the edge of life (McMurdo Dry Valleys, Antarctica)

“…The presence of the latter two taxa only in continental Antarctica, they are not known from other studies that have focused on or included algal samples from outside continental Antarctica (Romeike et al ., ; Engelen et al ., ; Fernández‐Mendoza et al ., ), suggests that they could be endemic in this extreme area. It has been shown recently that environmental conditions largely affect the distribution of photobiont taxa (Peksa & Škaloud, ) and that some eurioic lichen species with wide large distributions are able to lichenize with different photobiont taxa across their distribution range (Blaha et al ., ; Fernández‐Mendoza et al ., ).…”

A multigene phylogenetic synthesis for the class Lecanoromycetes (Ascomycota): 1307 fungi representing 1139 infrageneric taxa, 317 genera and 66 families

“…Selected literature used for the photobiont assignment: Backor et al, 2010; Baloch et al, 2010; Beck, 2002; Brodo, 1990; Brodo et al. 2001; Coppins and Purvis, 1987; Dal Grande et al, 2014; Engelen et al, 2010; Fernández-Mendoza et al, 2011; del Hoyo et al, 2011; Friedl and Büdel, 2008; Gueidan et al, 2014; Höggnaba et al, 2009; Kantvilas, 2004; Lücking et al, 2009; Miadlikowska et al, 2006; Muggia et al, 2011; Nash et al 2002, 2004; Otálora et al, 2010b, 2013c; Peksa and Skaloud, 2011; Purvis et al, 1992; Raggio et al, 2012; Skaloud and Peksa, 2010; Spribille and Muggia, 2012; Tschermak-Woess, 1988; Voytsekhovich, 2013; Voytsekhovich et al., 2011a, b.…”