Ecophysiology and phylogeny of new terricolous and epiphytic chlorolichens in a fog oasis of the Atacama Desert

Abstract

The Atacama Desert is one of the driest and probably oldest deserts on Earth where only a few extremophile organisms are able to survive. This study investigated two terricolous and two epiphytic lichens from the fog oasis “Las Lomitas” within the National Park Pan de Azúcar which represents a refugium for a few vascular desert plants and many lichens that can thrive on fog and dew alone. Ecophysiological measurements and climate records were combined with molecular data of the mycobiont, their green algal photobionts and lichenicolous fungi to gain information about the ecology of lichens within the fog oasis. Phylogenetic and morphological investigations led to the identification and description of the new lichen species Acarospora conafii sp. nov. as well as the lichenicolous fungi that accompanied them and revealed the trebouxioid character of all lichen photobionts. Their photosynthetic responses were compared during natural scenarios such as reactivation by high air humidity and in situ fog events to elucidate the activation strategies of this lichen community. Epiphytic lichens showed photosynthetic activity that was rapidly induced by fog and high relative air humidity whereas terricolous lichens were only activated by fog.

Biocrust-linked changes in soil aggregate stability along a climatic gradient in the Chilean Coastal Range

“…Typical sources of soil water are precipitation in general and, more specifically, at valley bottoms with a close connection to the groundwater table, also groundwater. Furthermore, available water for lichen growth can be provided by fog and dew (Jung et al, 2019). Pore space, pore size, and following water-holding capacity of a soil largely depends on the parent material and its degree of weathering.…”

Lichens Bite the Dust – A Bioweathering Scenario in the Atacama Desert

“…The large diurnal temperature range, for example (e.g. Jung et al., 2019a ), causes thermal stress (insolation weathering) in the granitoid particles as differences in mineral expansion set up cause the polycrystalline rocks to crack preferentially at grain boundaries ( Vasile and Vespremeanu-Stroe, 2017 ) which offers a great ecological niche for microbes of any kind. However, the bioweathering processes on which this study focused were those mediated by lichens, cyanobacteria and fungi that support the deterioration of rocks from a microscope to the landscape perspective and from the rock to the fine substrate as depicted in a possible chronosequence in Figure 1 .…”

“…Nevertheless, the process of alkalinolysis can be transferred to lichens because the photobionts were able to increase the pH in the experiments which means it is likely that they could do this in the lichens as well even during short terms of activity induced by e.g. fog ( Jung et al., 2019a ). This will result in alkalinolysis effects on the microscale where, e.g., a quartz fragment is stuck in the lichen thallus touching a few photobionts, which was indeed observed ( Figure 5 D).…”

Leben zwischen Eis und Felsen

“…Die für die Antarktis endemische Flechte Acarospora gwynii (Abbildung ) reagiert aber bei CO 2 ‐Gaswechselmessungen selbst auf eine Luftfeuchtigkeit von über 98 Prozent nicht . Aktuell geht man deshalb davon aus, dass diese Fähigkeit artabhängig ausgeprägt ist, was durch Beobachtungen an Flechten besonders trockener Habitate, wie etwa der Atacama‐Wüste Chiles oder der Wüste von Tabernas in Spanien bekräftigt wird .…”