Abstract Detail

Bryological and Lichenological Section/ABLS

Trest, Marie [1], Will-Wolf, Susan [2], Keuler, Rachel [2], Shay, Nathaniel [2], Hill, Karen [2], Studer, Alyssa [2], Muench, Andy [2], Alexander, Zachary [2], Adams, Axel [2], Dittberner, Leah [2], Feehan, Martin [2], Lee, Hannah [2], Galleguillos-Katz, Nicholas [2], Zedler, Joy [3], Graham, Linda [4], Arancibia-Avila, Patricia [5].

Potential impacts of the southern ozone hole in Chile on lichen communities of Nothofagus dombeyi trunks: A pilot study.

Lichen communities of southernmost Chile are recognized for their high diversity, but they face the triple threats of deforestation, climate warming, and increased exposure to UV arising from polar ozone depletion . These communities include nitrogen (N)-fixing cyanolichens that are common on forest trees, contribute N to forests, and are sensitive to exposure following deforestation. In a pilot study of exposure effects on tree lichens, and using non-destructive imaging methods, an undergraduate class compared lichen communities on trunks of isolated versus forest tree trunks of Southern Chilean beech (Nothofagus dombeyi, Nothofagaceae). We chose trees of similar diameter and trunk lean angle in conserved forest and a nearby logged meadow on Navarino Island, XII Region Magallanes and Chilean Antarctica, under the annual southern ozone hole. In all, 95% of cyanolichen records, including Nephroma antarcticum, and 66% of records for other foliose lichens were from the forest, whereas pendulous usneoid lichens dominated Nothofagus dombeyi bark at the meadow site. Limited cyanolichen growth on isolated trees could affect ecosystem function by reducing input of fixed N. Strong community differences were linked to increased visible light intensity, UV radiation and wind stress, and possibly to limited ability of lichens to colonize isolated trees in the logged meadow. UV radiation was likely an important stressor for some lichen species, not others. For instance, other surveys in similar (though probably less windy) habitats just outside the southern ozone hole have reported healthy foliose and cyanolichens on isolated Nothofagus dombeyi trees. We recommend extensive monitoring soon in this poorly studied habitat, and research to pinpoint causes of differing lichen communities in bark-dwelling lichens in southern hemisphere regions facing multiple threats.

1 - University of Wisconsin-Madison, Department of Botany, 430 Lincoln Drive, Madison, WI, 53711-1381, USA
2 - University Of Wisconsin-Madison, Department Of Botany, 430 Lincoln Drive, Madison, WI, 53706, USA
3 - University Of Wisconsin, Botany, 430 Lincoln Drive, Madison, WI, 53706, USA
4 - University Of Wisconsin, Botany Dept, 430 Lincoln Drive, Madison, WI, 53706, USA
5 - University of Bio-Bio, Department of Basic Sciences, Chillan, 3800708, Chile

Keywords:
bark lichens
cyanolichens
Chile
deforestation
forest fragmentation
diversity
lichen
Nothofagus dombeyi
southern ozone hole
UV radiation.

Presentation Type: Oral Paper:Papers for Sections
Session: 70
Location: Salon 10/The Shaw Conference Centre
Date: Wednesday, July 29th, 2015
Time: 3:00 PM
Number: 70007
Abstract ID:421
Candidate for Awards:None