Lichens of Alaska's South Coast
Lichens of Alaska’s South Coast United States Department of Agriculture Forest Service Alaska Region R10-RG-190 July 2011 WHAT IS A LICHEN? Lichens are specialized fungi that “farm” algae as a food source. Unlike molds, mildews, and mushrooms that parasi ze or scavenge food from other organisms, the fungus of a lichen cul vates ny algae and / or blue-green bacteria (called cyanobacteria) within the fabric of interwoven fungal threads that form the body of the lichen (or thallus). The algae and cyanobacteria produce food for themselves and for the fungus by conver ng carbon dioxide and water into sugars using the sun’s energy (photosynthesis). Thus, a lichen is a combina on of two or some mes three organisms living together. Perhaps the most important contribu on of the fungus is to provide a protec ve habitat for the algae or cyanobacteria. The green or blue-green photosynthe c layer is o en visible between two white fungal layers if a piece of lichen thallus is torn oﬀ. Most lichen-forming fungi cannot exist without the photosynthe c partner because they have become dependent on them for survival. But in all cases, a fungus looks quite diﬀerent in the lichenized form compared to its free-living form. HOW DO LICHENS REPRODUCE? Figure 1. Apothecia, fruiting bodies Figure 2. Soralia, small openings on thallus surface. Figure 3. Soredia, dust-like granules. Lichens sexually reproduce with frui ng bodies of various shapes and colors that can o en look like miniature mushrooms. These are called apothecia (Fig. 1) and contain spores that germinate and grow into the fungus. Each fungus must find the right photosynthe c partner in order to become a lichen. Lichens reproduce asexually in several ways. Some lichens have openings on the thallus surface called soralia (Fig. 2). Inside, ny dust-like granules called soredia (Fig. 3) are produced. Soredia contain algae and fungal cells that escape from the parent lichen and grow into a new lichen thallus. Other lichens produce outgrowths that break oﬀ and grow into the same lichen they came from. These are called isidia ( ny, cylindrical projec ons, Fig. 4) or lobules (li le flaps of ssue, Fig. 5). These structures are o en very important to no ce for the proper iden fica on of lichens. DIVERSITY AND ECOLOGY Lichens come in many shapes, Figure 4. Isidia, tiny projections. sizes, and colors. A lichen thallus has one of three general growth forms: foliose, fru cose, or crustose. Foliose lichens are leaf-like with diﬀerent upper and lower surfaces. Fru cose lichens are hair-like or bushy with no Figure 5. Lobules, flaps of tissue. obvious diﬀerence between upper and lower surfaces. Crustose lichens are so closely a ached to a surface, like paint spots, that the lower surface is not easily observable. Lichens have specialized features enabling them to survive long periods of drought. In a dehydrated, inac ve state they can resist extreme high and low temperatures and s ll func on op mally whenever condi ons become just right. Well adapted for life in marginal habitats, lichens produce more than 500 unique biochemical compounds that serve to control light exposure, repel herbivores and microbes, and discourage compe on from plants. Among these are many pigments and an bio cs that are useful to humans. Lichens are considered to be nature’s pioneers because they colonize newly exposed surfaces. Lichens containing cyanobacteria fix their own nitrogen from the air into a form usable by other plants as a form of fer lizer. This form of nitrogen is released into the environment as rain washes over the lichens or when lichens die and fall to the ground. These lichen types tend to live in nitrogen-poor habitats such as bare rock surfaces, the forest canopy, or on sandy soils. Lichens provide food for many animals including flying squirrels, black-tailed deer, and mountain goats. Many invertebrates use lichens for food or for shelter. The diverse ecosystems along the south coast of Alaska provide abundant habitats for the more than 1,000 diﬀerent lichens known to occur here. Some are very rare and cryp c. Many lichens are generalists and can grow in more than one habitat. Some lichens only grow in specific habitats such as upper dal rocks, conifer forests, alpine, or sandy soils near glaciers. LICHENS AND AIR QUALITY MONITORING Lichens are not protected by bark, nor do they possess an external waxy layer to prevent water loss like plant leaves. Lacking roots and other structures to transport food and water, lichens absorb moisture into the thallus directly from the humid air or rainfall, and can become quickly saturated like a sponge. Lichens dry out by losing moisture through evapora on when windy or dry condi ons exist. As drying occurs, elements and compounds that entered with moisture from the surrounding environment become concentrated in the lichen. During high rainfall periods, mobile nutrients and pollutants are slowly leached from the lichen. In this way lichens serve as dynamically representa ve samples of the environmental condi ons in which they are growing. Lichen species diﬀer in their tolerance to air pollutants, with responses ranging from rela vely resistant to highly sensi ve. Measurements of metals, nitrogen, and sulfur content in lichens at diﬀerent loca ons indicate the rela ve amounts of pollu on in the air. Noted in this brochure are the lichens used for determining and monitoring air quality on some federally-managed land along the south coast of Alaska. The lichens featured in this brochure are arranged by the three general growth forms described above: foliose, fru cose, and crustose. Alaska’s South Coast Ecoregions Pacific Coastal Mountains Coastal Western Hemlock-Sitka Spruce Forests Cook Inlet Alaska Peninsula Mountains Alaska Range Source: Nowacki, G., P. Spencer, M. Fleming, T. Brock, and T. Jorgenson. 2002 Unified Ecoregions of Alaska: 2001. USGS Open File Report 02-297 Foliose Beaded Tube lichen Hypogymnia apinnata Thallus made up of tube-like lobes, constricted at intervals, usually has a hole at the p of each lobe; white upper surface and black underneath. Apothecia raised and brown. Occurs in forests of all types (conifers and hardwoods), but not in deep shade. Used in air quality monitoring. Thirteen species of Hypogymnia occur in this region. Gray lungwort Lobaria halli Large leaf-like thallus, light gray when dry, dark gray when wet. Soralia brown to gray and some mes ring-like on upper surface. Contains cyanobacteria. Found in Sitka spruce and hardwood forests, but more common on sites with co onwood, birch, and alder. Nine species of Lobaria occur in this region. Cabbage lungwort Lobaria linita Large leaf-like thallus, green or brownish-green when dry, bright grass-green when wet. O en with abundant, orange apothecia on upper surface. Contains cyanobacteria. Used as winter forage by mountain goats. It grows in shady coniferous forests on the lower part of tree trunks. Foliose LeƩuce lichen Lobaria oregana Large leaf-like thallus; pale yellowish-green on top, white and tan on the bo om. Lobe margins decorated with ny, flat lobules. Contains cyanobacteria. Occurs in the canopy of oldgrowth forests and along natural forest edges. Used in air quality monitoring. Lungwort Lobaria pulmonaria Large leaf-like thallus; pale brown to olive-brown when dry, bright green when wet. Strongly pi ed upper surface with soralia on lobe margins. Contains cyanobacteria. Occurs in riparian Sitka spruce forests, hardwood forests, and mari me beach forests. ArcƟc Kidney lichen Nephroma arcticum Large thallus; yellowishgreen when dry, bright green when wet. Broad, flat, gray bumps on surface that contain cyanobacteria. Lower surface pale tan at the edge. Large orange-brown apothecia. In coniferous forests and occasionally on the forest floor or old logs. At least nine species of Nephroma occur in this region. Foliose Pimpled kidney lichen Nephroma resupinatum Medium-sized thallus; upper surface brown to grayishbrown, lobe ps with woolly appearance. Lower surface pale, fuzzy with sca ered whi sh bumps. Contains cyanobacteria. Grows in humid forests on hardwoods and conifers. Salted shield lichen Parmelia saxatilis Small thallus of ny fla ened lobes; 2–4 mm wide, pale green to gray. Upper surface with small net-like ridges and isidia, underside with black rhizines (small s ﬀ hairs). Apothecia brown, but not always present. In many habitats including coniferous and hardwood forests, rocks and logs in upper dal zones and alpine areas. Seven species of Parmelia occur in this region. Flaky freckle pelt Peltigera britannica Large thallus; brownish-green when dry, grass green when wet. Underside has raised veins with ny rhizines. Lobes have small granules that rub oﬀ easily and contain cyanobacteria. In humid forests on tree trunks, branches, and mossy soil. Over twenty species of PelƟgera occur in this region. Foliose Medium-sized thallus; gray to dark brown. Upper surface smooth with bluish-gray soredia usually covering lobe margins; lower surface pale with small raised veins and tu ed rhizines. Apothecia are reddish brown when present. Contains cyanobacteria. In humid forests on conifers and hardwoods. Varied rag lichen Platismatia glauca Medium-sized thallus; pale greenish-gray, o en brown at the edges. Lobe margins very frilly with soredia and isidia. Lower surface shiny and brown with white patches. In the canopy of coniferous forests and on hardwoods. Used in air quality monitoring. Four species of PlaƟsmaƟa occur in this region. Crinkled rag lichen Platismatia lacunosa Medium-sized thallus; pale green to almost white. Upper surface deeply pi ed and ridged with a dark grey color in the pi ed areas. Apothecia are brown but not always present. In coniferous forest canopy and on hardwoods. Photo by Linda Geiser Tree pelt lichen Peltigera collina Foliose Dimpled specklebelly lichen Pseudocyphellaria anomala Medium to large thallus; chocolate to reddish-brown. Upper surface with a network of ridges and dimples; ridges set oﬀ by white and gray soredia. Lower surface with conspicuous raised, white dots. In humid forests on conifers and hardwoods. Five species of Pseudocyphellaria occur in this region. Orange chocolate chip lichen Solarina crocea Medium-sized thallus; olivebrown to olive-gray on upper surface, lower surface bright orange with veins and sca ered rhizines. Apothecia are brown and sunk into upper surface. Contains cyanobacteria. On soils in moist areas under late snow patches or seepage areas in cold, open habitats. Four species of Solarina occur in this region. Rock tripe Umbilicaria spp. Thallus small, flat, and wrinkled, circular in shape; brownish-gray and bri le when dry, greenishblack and rubbery when wet. A ached from a single point of the thallus to the rock. On rock in open, cold habitats. At least fi een species of Umbilicaria occur in this region. Fruticose Witch’s hair Alectoria sarmentosa Thallus long, hanging loosely, o en twisted and somewhat fla ened strands; pale greenish with small, raised white ridges on surface. Occasional brown apothecia. On conifers and hardwoods in all forest types, from sea level to alpine. Important winter food for blacktailed deer. Used in air quality monitoring. Three species of Alectoria occur in this region. Gray horsehair lichen Bryoria capillaris Thallus long; pale gray to dark smoky brown, hanging in clumps, with slender strands containing long narrow slits on the surface. In old-growth forest habitats and forested peatlands on conifers and hardwoods. Important genus for wildlife forage and nes ng material. At least fi een species of Bryoria occur in this region. Toy soldiers Cladonia bellidiflora Small thallus made up of pale, yellow-green and frilly lobes. Contains small, erect, branchlike stems ending in cup-shaped ps rimmed with bright red apothecia. On ro ng stumps and logs, bare soil, and among mosses in the open and in all forested habitats. Over 60 species of Cladonia occur in this region. Fruticose Smooth cladonia Cladonia gracilis Small thallus of green frilly lobes containing variable sized, erect, branch-like stems. The smooth, pointed stems do not contain soredia and are greenish to olive, becoming browned in exposed habitats. On ground and rocks in exposed habitats. Thallus branching or tree-like form; white to silver gray, somewhat browned ps of branches. Main stems and side branches commonly occur in twos and threes, some mes fours. On the ground in open, humid habitats like muskegs, growing among mosses and other lichens. Principle winter food for caribou in North America. Photo by Linda Geiser Gray reindeer lichen Cladonia rangiferina Small thallus; pale graygreen and granular. Erect stalks protrude from thallus and end with shiny, black spherical apothecia. Contains cyanobacteria. On rock surfaces in open habitats at all eleva ons. Five species of Pilophorus occur in this region. Photo by Rick Turner Devil’s matchsƟck Pilophorus acicularis Fruticose DoƩed Ramalina Ramalina farinacea Thallus short and bushy; pale yellow to yellowish-green branches, narrow and flat with rounded soralia containing powdery soredia along branch margins. On conifers, hardwoods, and shrubs in humid forests. Some mes on rocks in sheltered humid areas. At least eight species of Ramalina occur in this region. Thallus made up of white, dented stalks, mostly unbranched, in dense clumps. On soil or mud in sun-exposed seeps in muskegs and alpine areas. Some mes submerged in water. This is the only species of Siphula occurring in North America. Coral lichen Sphaerophorus venerabilis Thallus forming erect tu s up to 10 cm diameter; variable in color from cream in shady habitats to copper-brown in exposed habitats. Main stem with shallow surface depressions and very few branchlets. Stems o en ending with globe-like apothecia that are slit open to reveal sooty black spores. In forested habitats on bark and wood. Four species of Sphaerophorus occur in this region. Photo by Rick Turner Waterfingers Siphula ceratites Fruticose Foam lichen Stereocaulon spp. Thallus medium-sized; pale gray to white branch-like stalks with ny, frilly lobules and pink or brown wart-like structures that contain cyanobacteria. Stalks of some species may be pped with black or brown apothecia. On soil and rocks in open habitats. Important pioneer species in disturbed areas. Over twentyeight species of Stereocaulon occur in this region. Tundra spagheƫ Thamnolia subuliformis Thallus occasionally forming upright, white to creamy, stringy turfs but usually prostrate or sprawling. Thallus strings are roundish in cross sec on with tapering ends and have simple branching. On soil and rock crevices in sub-alpine to alpine areas. Two species of Thamnolia occur in this region. Methusula’s beard Usnea longissima Thallus o en long (up to 2 m or more); pale greenish. Hanging freely, with one long main branch and many short, perpendicular side branches, all cylindrical. Surface o en with circular cracks and white patches. On conifers and hardwoods in humid and open forest habitats within a few miles of salt water. Sensi ve to air pollu on, especially sulfur dioxide and acid rain. At least fi een species of Usnea occur in this region. Crustose Fairy barf Icmadophila ericetorum Thallus pale to grey-green with pink to brown apothecia. On old stumps and logs in shady habitats. This is the only species of Icmadophila occurring in North America. Orange boulder lichen Porpidia flavocaerulescens Thallus bright orange, some mes with gray patches, and without soredia. Apothecia black or greyish. On exposed rocks in splash zone of marine beaches to alpine. Many species of Porpidia occur in this region. Photo by Rick Turner Bull’s eye lichen Placopsis ssp. Thallus pinkish-white to yellowish-brown, o en turning pale green at the edges when wet; large brown spots containing the cyanobacteria are almost always present near the center of the round thallus. Sca ered apothecia are pink to brown disks with a white rim. On rock in open areas. O en a primary invader of newly exposed rock surfaces like roadsides and glacial areas. Three species of Placopsis occur in this region. Crustose Yellow map lichen Rhizocarpon geographicum Thallus of yellow bumps with black apothecia tucked between the bumps. On rock surfaces in open, cold alpine habitats and near glaciers. Used in es ma ng the ages of recent geomorphic exposures, par cularly glacial moraines. At least eleven species of Rhizocarpon occur in this region. Exposed rocks are good habitats to look for colorful crutose lichen displays (shown are in the genera Porpidia, Ochrolechia and several others). Further readings about lichens: Macrolichens of the Pacific Northwest, Second Edi on, 2009, by Bruce McCune and Linda Geiser; Lichens of North America, 2001 by Irwin Brodo, Silvia Duran Sharnoﬀ, and Stephen Sharnoﬀ; Lichens of Bri sh Columbia, Illustrated Keys, Part 1 and 2. 1994 and 1999, by Trevor Goward; American Arc c Lichens 1. The macrolichens, 1984, 2. The microlichens 1997, by John W. Thomson. This brochure highlights 31 of the more than 1,000 lichens found across the south coast of Alaska (from Kodiak Island to Ketchikan). This region includes the Tongass and Chugach na onal forests, the Glacier Bay, Lake Clark, Katmai, and Wrangell-St. Elias na onal parks and preserves, the Klondike Gold Rush and Sitka na onal historical parks, Kenai Fjords Na onal Park, and the US Fish and Wildlife Service Kodiak, Kenai, and Mari me na onal wildlife refuges. This brochure was prepared by the botany program of the Forest Service, Alaska Region. Photographs are by Karen L. Dillman unless otherwise noted. Drawings are by Alexander Mikulin. The Forest Service maintains a website on air quality and lichens for the Pacific Northwest region that includes Alaska at h p:// www.fs.fed.us/r6/aq/lichen/welcome.htm. Lichens are used in air quality monitoring in Alaska. In cooperation with: USDA is an equal opportunity provider and employer.