Potential impacts of uv exposure on lichen communities: a pilot study of nothofagus dombeyi trunks in southernmost chile

Abstract

High-latitude terrestrial ecosystems face the triple threats of climate warming, increased exposure to UV arising from polar ozone depletion, and deforestation. Lichen communities of southernmost Chile are recognized for their high diversity, which includes nitrogen-fixing cyanolichens. Such lichens are common on forest trees, contribute nitrogen to forests, and are sensitive to exposure following deforestation (widespread in this region). In a pilot study of exposure effects on tree lichens, using nondestructive imaging methods, we compared lichen communities on trunks of isolated vs. forest tree trunks of southern Chilean beech (Nothofagus dombeyi, Nothofagaceae). We chose trees of similar diameter and trunk lean angle in conserved forest and nearby logged meadow on Navarino Island, XII Region Magallanes and Chilean Antarctica, Chile, within the annual southern ozone hole. Ninety-five percent of cyanolichen records, including Nephroma antarcticum, and 66% of records for other foliose lichens were from the forest, whereas pendulous usneoid lichens dominated N. dombeyi bark at the meadow site. Limitation of cyanolichen growth on isolated trees could affect ecosystem function in this poorly studied habitat. Possible factors contributing to strong community differences were increased light intensity, UV radiation, and wind stress, plus limited ability of lichens to colonize isolated trees in the logged meadow. UV radiation was likely an important stressor for some lichen species but not others. We recommend more extensive monitoring to pinpoint causes of differing lichen communities, and we encourage better protection of bark-dwelling lichens in southern hemisphere regions facing multiple threats.

Catálogo de líquenes (y algunos hongos relacionados) de la isla Navarino, Reserva de la Biosfera Cabo de Hornos, Chile

“…Previously recorded in Navarino as Coelopogon spp. by , and also by Santesson in Naturhistoriska riksmuseet (2021), Trest et al (2015), Etayo and Sancho (2008) and (Smith et al 2009), it has not been recorded before in southern Chile but in the Falkland Islands (Fryday et al 2019).…”

“…Recorded by Santesson in Naturhistoriska riksmuseet (2021), , Etayo and Sancho (2008), and Trest et al (2015) from Navarino.…”

On the distribution and habitat use of the sub‐Antarctic fly Hyadesimyia clausa Bigot (Diptera, Tachinidae) according to citizen science

“…Studies into the terrestrial invertebrate assemblages of these sub-Antarctic biomes have mainly focused on extreme ecosystems, such as peatlands and subantarctic grasslands (see examples in Contador et al, 2020;Lanfranco, 1980Lanfranco, , 1981Lanfranco, , 1983 or Nothofagus forest (Lanfranco, 1977). The weather conditions include ambient temperatures between 3.1 and 6.9°C, mean rainfall of 460-1200 mm, and high UVA + UVB conditions (Schlatter & Riveros, 1997;Trest et al, 2015). In addition, some particular biological relationships in the sub-Antarctic Ecoregion, such as the use by subantarctic mosses of coprophilous flies for reproductive purposes (Jofré et al, 2011), pose new ecological questions based on gaps in our knowledge of these biological processes, which have been poorly explored.…”

Exposure to UV-B Radiation Leads to Increased Deposition of Cell Wall-Associated Xerocomic Acid in Cultures of Serpula himantioides

“…The effect of radiation on secondary metabolites of S. himantioides was studied using high-intensity UV-B energy (0.12 mW/cm 2 ), which is similar to the UV-B radiation levels in the south of Chile (61,62). In vitro cultures were performed using 2-liter flasks that were kept at 25°C for the entire experiment.…”