Morphology drives water storage traits in the globally widespread lichen genus Usnea

Abstract

Links between lichen morphology, internal/external water storage and distribution patterns are poorly known. We compared mass- (WC, % H2O) and area-based (WHC, mg H2O cm(-2) ) hydration traits in seven pendent or shrubby Usnea species from oceanic to continental climates. All species held more external than internal water. Internal WHC and WC increased with specific thallus mass (STM, mg cm (-2) ), while external WC decreased. Shrubby species had higher STM and total WHC than pendent ones. The continental Usnea hirta (shrubby) had the highest total and external storage; the suboceanic Usnea longissima (pendent) had the lowest internal storage. Morphology drives hydration traits and explains distributions of some Usnea species, but such traits did not distinguish oceanic from widespread species. Shrubby species maximize water storage and thus prolong hydration after rainfall events and/or hydration by dew. The low internal WHC in pendent species is likely an adaptation to frequent hydration in humid air. (C) 2018 Elsevier Ltd and British Mycological Society. All rights reserved.

Keywords

Epiphytic lichens; Functional traits; Specific thallus mass; Water-holding capacity; Water content

Published in

Fungal Ecology
2018, Volume: 35, pages: 51-61

UKÄ Subject classification

Ecology


Publication identifier

DOI: https://doi.org/10.1016/j.funeco.2018.06.007

Permanent link to this page (URI)

https://res.slu.se/id/publ/100474