Sunscreening fungal pigments influence the vertical gradient of pendulous lichens in boreal forest canopies.

Farber, Leonie, Solhaug, Knut Asbjorn, Esseen, Per-Anders, Bilger, Wolfgang and Gauslaa, Yngvar (2014) Sunscreening fungal pigments influence the vertical gradient of pendulous lichens in boreal forest canopies. Ecology, 95 (6). pp. 1464-1471. DOI 10.1890/13-2319.1.

Full text not available from this repository.

Supplementary data:

Abstract

Pendulous lichens dominate canopies of boreal forests, with dark Bryoria species in the upper canopy vs. light Alectoria and Usnea species in lower canopy. These genera offer important ecosystem services such as winter forage for reindeer and caribou. The mechanism behind this niche separation is poorly understood. We tested the hypothesis that species-specific sunscreening fungal pigments protect underlying symbiotic algae differently against high light, and thus shape the vertical canopy gradient of epiphytes. Three pale species with the reflecting pigment usnic acid (Alectoria sarmentosa, Usnea dasypoga, U. longissima) and three with dark, absorbing melanins (Bryoria capillaris, B. fremontii, B. fuscescens) were compared. We subjected the lichens to desiccation stress with and without light, and assessed their performance with chlorophyll fluorescence. Desiccation alone only affected U. longissima. By contrast, light in combination with desiccation caused photoinhibitory damage in all species. Usnic lichens were significantly more susceptible to light during desiccation than melanic ones. Thus, melanin is a more efficient light-screening pigment than usnic acid. Thereby, the vertical gradient of pendulous lichens in forest canopies is consistent with a shift in type and functioning of sunscreening pigments, from high-light-tolerant Bryoria in the upper to susceptible Alectoria and Usnea in the lower canopy.

Document Type: Article
Keywords: Alectoria sarmentosa boreal forest Bryoria spp desiccation tolerance epiphytes melanin photoinhibition sunscreening pigments Totenåsen, Norway Usnea spp usnic acid Vindeln, Sweden
Research affiliation: Kiel University > Kiel Marine Science
OceanRep > The Future Ocean - Cluster of Excellence
Kiel University
Refereed: Yes
Open Access Journal?: No
DOI etc.: 10.1890/13-2319.1
ISSN: 0012-9658
Projects: Future Ocean
Date Deposited: 30 Mar 2015 12:09
Last Modified: 21 Jun 2019 10:51
URI: http://oceanrep.geomar.de/id/eprint/27493

Actions (login required)

View Item View Item