A preliminary investigation of the lichen biota associated with recently deglaciated terrain in southeastern Alaska

Abstract

Glaciers worldwide are currently retreating at unprecedented rates, revealing large tracts of newly exposed rock and till. We present the results of a preliminary, qualitative investigation of the lichen diversity of transient habitats near three glaciers in southeastern Alaska: Muir Glacier within Glacier Bay National Park, and Baird and Patterson Glaciers in the Tongass National Forest. This work is noteworthy as it (i) documents previously undescribed lichen species and communities within rapidly changing glacier habitats, (ii) illustrates the importance of cryptogams (lichens, bryophytes, algae, and cyanobacteria) in the primary colonization of recently deglaciated terrain, (iii) sets apart the lichen biota of recently deglaciated terrain in southeastern Alaska from that of other glacial regions worldwide (e.g., the European Alps, Svalbard, and southern South America) and even other parts of Alaska (e.g., Brooks Range), and (iv) emphasizes the importance of more lichen studies that focus on this rapidly changing habitat. The lichen biotas found at different successional stages near these glaciers are described and compared. The role of lichens and other cryptogams in post-glacial vegetation initiation, the threats to the lichen biota, and suggestions for the possible origins of the lichen propagules that colonize these newly exposed surfaces are also discussed.