Another checklist this on the lichens identified on my property which as of July 1, 2016 is at 70 species from 44 genera. Besides the species identified there are several specimens of crustose (crust-like) forms identified, some with reservation, to genus only. These are Bacidia, Buellia, Lecidella, Mycobilimbia, and Placynthiella. There is also a large group that I have not yet identified even to genus. The number in this group stands at 40 distinct lichens from crustose to foliose (leaf-like) to fruticose (bushy) types.
Identifying lichens requires careful observation of form (crustose, foliose, fruticose), color (both wet and dry), textures and other characteristics of the upper surface like spots and fissures, characteristics of the lower surface like color, texture, and any outgrowths, color of the interior of the lichen, and presence or absence of any spore producing bodies including their shape, color, and position. Use of a millimeter ruler is also important for measuring widths of various parts of the lichen body.
Many physical characteristics of lichens are best observed under magnification. 10x magnification is usually best unless trying to observe spores in which case a microscope is essential especially for many crustose lichens.
Chemical reagents (chlorine bleach, a potassium hydroxide solution or lye) are used to test for lichen substances which are phenolic compounds produced by many lichen-forming fungi. These compounds are often crucial in separating similar species or genera. Ultraviolet light is also helpful in lichen identification as many lichen substances are fluorescent.
My interest in lichens goes back many years when I was trying to learn certain listed rare species for biodiversity inventory work. It was not until the last 10 or so years that I began a more intensive effort to learn more of them especially the ones growing on my property.
There are an estimated 700 species of lichens in Minnesota. Many are very common and can be found growing in almost every county in the state. Flavoparmelia caperata (green shield lichen) is one such species and grows on coniferous and deciduous tree bark and on rocks. Xanthoria fallax (sunburst lichen) is also common on hardwood trees like aspen and willow. Another common and easily identified species is Physcia millegrana (rosette lichen) which does well on the bark of deciduous and coniferous trees in many environments even in cities.
Physcia millegrana (rosette lichen)
Flavoparmelia caperata (green shield lichen)
Some lichen species in Minnesota are uncommon or only known from a handful of sites. These rare species are also usually specialized and require specific rock or tree bark substrates. The pH and chemistry of the substrates may be limiting factors for these species. Some species in the state are rare because they are at their known range limits but may be very common just a few hundred miles away. Only one state-listed rare species is known to occur on my property, Lobaria querzicans, but there may be others especially among the obscure crustose forms. The majority of lichens identified on my property are common or frequent in the state and the Western Great Lakes Region.
A few of the lichens found grow in very old forests and old-growth forests. These include Heterodermia speciosa, Lobaria pulmonaria, L. querzicans, Myelochroa auralenta, Pertusaria velata, and Punctelia appalachensis which have been found in forests on trees 60 or more years old. The growth of these lichens is slow and the trees on which I have found these species grow are all very old. Lobaria pulmonaria, for example, will take ten years from initial colonization as a propagule with its photobionts before it is large enough to produce the first apothecia (spore cups).
Most of my lichen searches have been made in forests but there is a large wetland area in the central part of the property that is vegetated by shrub willows and alders. These might be home to species not found in the forests and will be a focus of future searches. Other habitats to investigate are old concrete walls, soil on the roots of overturned trees, and the tops of trees (available only when they blow over). And I’m going to need to dust off my microscopes to get a better view of the crustose lichens.
This year when photographing old wood like stumps, barn sides, and fence-posts I noticed tiny bristles on the wood surface. These bristles are about one or two millimeters tall and dark black with a round top. My first thought was these were a fungus. That turned out to be correct but they are more than just a fungus. They are lichenized fungi called stickpin, stubble, or whisker lichens. The latest ones I found are on an old pine stump but I have found them on very old weathered pine boards and cedar fence posts. I have also seen them on weathered black spruce snags.
Stickpin lichens are classed in the lichen family Caliciaceae which has about 21 genera. The genera that include stickpin, stubble, and whisker lichens are Calicium, Chaenotheca, Chaenothecopsis, Mycocalicium, Phaeocalicium, Sphinctrina, and Stenocybe.
The stickpin lichens I found on this stump and other weathered wood are dark black. The algal photobiont is subsurface as no green crust or film could be seen. My best guess at this point is that they are probably species in the genus Calicium or Mycocalicium but I won’t know for sure until I collect some of these tiny lichens and look more closely under a microscope.
Almost everyday I am finding new lichens and other fungi on my property. Even an old board like the one shown below can host an array of lichens. I know that I will never be able to find or identify them all but I will try to photograph, document and identify as many as I can.
Documenting Local Biodiversity: Multiclavula mucida, a Basidiolichen
This post is about a small lichen I found on my property in the spring of 2014. It is called Multiclavula mucida and is an unusual type of lichen. Although it is a widespread species in North America this lichen is easily overlooked. In fact, there are no records of it in the lichen herbarium collections for the state of Minnesota and only one for the related M. vernalis. So now, after a year of doing literature searches and also after finding more of these lichens in my woods I feel it is time to publish.
There were so many tiny plants and fungi sprouting in the forest last year after the long cold winter of 2013/2014. It was a wonderful sight and so much of it happened within in two weeks of the last snowfall in April. The odd fungal growth shown in the above photograph was found in the early spring of 2014 in my woods on a wet and decomposing balsam fir log. The tiny, pale club-like sprouts coming from this downed log are the fruiting bodies of a fungus that resembles coral mushrooms (Clavulina and Clavicorona) but are much smaller. The green film on the log is a green algae. The two organisms are growing together on the same substrate but the nature of the association is not immediately apparent.
Lichens, Basidiolichens and Ectomycorrhizal Fungi
Lichens are technically defined as organisms that arise when two or more separate organisms (a fungus and green algae or a cyanobacteria or both) become physically and physiologically united into a single form. The fungal hyphae encloses the photosynthetic symbionts and the combined organisms form a new shape, develop new physical functions and biochemistry that is unlike those found when the organisms grow separately. They are then said to be “lichenized”.
During those cold winter nights of 2013/2014 I had been reading about an unusual type of fungus-algae association called “Basidiolichens”. The growth on the balsam fir log resembled the Basidiolichens Multiclavula mucida and M. vernalis I had read about. Basidiolichens are a lichen-like association between an algae (or sometimes a cyanobacteria) and a fungus in the phylum Basidiomyceta which includes many familiar mushrooms such as Pleurotus and Agaricus, two edible mushrooms often sold in grocery stores. Three genera of Basidiolichens are reported from North America although this association is known from all continents except (so far) Antarctica. Basidiolichens status as real lichens is debated and not all lichenologists will include them as lichens. They lack a lichenized thallus, one that is not divided into cortical and medullary layers which enclose the photobionts. But Basidiolichens represent a different type of fungus/photobiont symbiosis which the traditional concept of lichen cannot adequately encompass.
In Basidiolichens a fungus and an algae are growing in close association. Is this a lichen or just a mushroom just that happens to be growing with an algae? The lichenized form, at least when compared to a lichen such as Lobaria, is not very obvious. The fungus and the algae appear to be very distinct. A kind of thallus is present but it is not a “lichen thallus” with various layers of cortex and medulla. The powdery vegetative reproductive structures (isidia or soredia) known from Ascomyceta lichens are not present. The odd fungus and algae together on the log now look more like an accidental association, a facultative rahter than an obligate association.
But is it facultative? All species of Multiclavulaknown only occur in association with the algae Coccomyxa. (Votik 2006) According to Voitk and Esteri (2011) what is happening is that the Multiclavula is not growing from the wood like a decomposer with the algae just being there coincidentally. Instead, it has formed a kind of ectomycorrhizal association with the Coccomyxa. The cells of the algae are enclosed in a manner similar to what occurs when an ectomycorrhizal fungus encloses the root tips of live trees in the forest. In this case though it is not root tips or root hairs that are enclosed but single-celled algae. Like the ectomycorrhizal fungi that associate with trees the Multiclavula and the Coccomyxa are in a mutually beneficial relationship. Interestingly, recent genetic research has shown Multiclavula belongs with the family Cantharellales many of which are well-known ectomycorrhizal fungi (Nelsen et al. 2007).
Species of Coccomyxa are photobionts not only with the fungus Multiclavula but with another basidiolichen fungus Omphalina and “real” lichens such as Solonia and Peltigera. Also, Coccomyxa and its relative Pseudococcomyxa are reported to be symbionts with Paramecium and some other ciliate protists. Those that form associations with protists appear to be able to live freely as well.
Some members of the Cantharellales like Multiclavula have extended the ectomycorrhizal propensity of the family to include single-celled photosynthetic organisms. When understood in this way all plant-fungi associations where the fungus gets its carbon-based nutrients from the products of the photobiont as opposed to decomposition are “lichens”. Included in this would be parasitic fungi which would be a subdivision of lichens not a separate category. The question, Voitk and Esteri (2011) say, as to “how much fungal tissue around algae, the shape of the ‘thallus’ or the degree of algal incorporation is needed to be called a lichen becomes somewhat moot. The mighty Quercus and the lowly Coccomyxa become equals, different expressions of a diverse fungal photobiontism, and envelopment, ectomycorrhiza and arbuscular mycorrhiza become but examples of mechanics.”
The combined Multiclavula and Coccomyxa are known as Multiclavula mucida (lichen genera are always named after the fungal partner). Because the fungus Multiclavula is a Basidiomycota the lichen Multiclavula mucida is sometimes called a Basidiolichen. This group of lichens is composed of a few other genera, none closely related. It is a rather small group and most species are found in tropical regions although some species are from the temperate zone and even the Arctic. The species M. mucida is cosmopolitan in its distribution. The vast majority of lichens are associations with members of the fungus phylum Ascomycota or sac fungi with a green algae and/or cyanobacteria. Here in Basidiomycota like M. mucida we see a parallel evolutionary development similar in many respects to what is seen in Ascomycota, algae, and cyanobacteria symbiosis.
M. mucida is easily recognized when the fungal fruiting bodies appear. These are about 1 to 5 mm tall, their caps pale yellow, sometimes pink tinged. The stem with the cap is spindle-shaped, the body of the stem is white with a few branches or none and often bent. Habitat for M. mucida is moist mixed conifer-hardwood or hardwood forests where it grows on moist decomposing logs either hardwood or conifer. Fruiting season is from late spring to fall. The 5-7 x 2.5-3 µm spores are ellipsoid. I have observed that the fruiting bodies persist over the winter into the following spring as does the algal thallus.
Nelsen, M. P. (2005). The basidiolichen Multiclavula mucida (Fr.) Petersen: new to Michigan. The Michigan Botanist 44: 192–193.
Nelsen, M. P., Lücking, R., Umaña, L., Trest, M. T., Will-Wolf, S. Chaves, J. L., and Gargas, A. (2007). Multiclavula ichthyiformis (Fungi: Basidiomycota: Cantharellales: Clavulinaceae), a remarkable new basidiolichen from Costa Rica. Amercan Journal of Botany, Volume 94(8):1289-96.
Nelsen, M. P. (2007). Noteworthy Collection: Multiclavula vernalis (Schw.) Petersen (Clavulinaceae). The Michigan Botanist 46: 124–126.
I think this post is done (until I find an error of some sort) and I just want to get it out there so I can start posting about my plans for the 2015 vegetable and iris gardens. Lichens interest me a lot so there will be many more posts on them covering species I’ve identified on my land. Who knows but maybe there will be another one on a rare species?
In my previous local biodiversity post, Another Lungwort Lichen, Part 1, I wrote about my discovery of additional Lobaria pulmonaria colonies and newly discovered colonies of L. quercizans, a rare lichen species, in the Black Ash/Tag Alder Zone which is a remnant black ash swamp inclusion in the Tamarack Swamp. After making these finds in the remnant black ash swamp I now wondered about another black ash wetland (the Western Black Ash Swamp) on the west side of my land and if any Lobaria grew there. At about seven acres this swamp is larger than the inclusion in the Tamarack Swamp and differs in several other important ways as well.
The Western Black Ash Swamp Habitat Description
The Western Black Ash Swamp is a groundwater fed seepage forested wetland in a 430 meters long by about 80 meters wide (for two-thirds of its length) trough with an average slope of 1.7%. However, the trough is not uniformly gradual in its descent and is marked by areas of level ground punctuated by steep slopes of 5% to 15% that level out again. Wherever there is a break in the slope there is a seepage but other seeps are only level ground. The seeps support colonies of the moss Rhizomnium punctatum and the vascular plants marsh marigold (Caltha palustris), swamp saxifrage (Saxifraga pensylvanica) and golden saxifrage (Chrysosplenium americanum, all indicators of strong groundwater influence. Some seeps are home to extensive mats of the great snakeskin liverwort. Level areas in the swamp are saturated at or just below the surface during the growing season and sometimes have pools of standing water in the spring. Water from the Western Black Ash Swamp drains into the same shrub carr and sedge meadow mentioned in Part 1. The outlet is wider though and measures 75 meters. The black ash swamp continues as a long narrow fringe for about 260 meters north between the upland fir-spruce-aspen-birch-white pine woods and the tag alder-willow shrub carr and sedge meadow. This fringe is also seepage-fed but the lower parts are often subject to flooding in the spring when the river overflows.
The density of trees is greater than that of the Black Ash/Tag Alder Zone on the eastern side resulting in a more closed canopy. The vitality and health of the trees is also very good and there is a greater variety of tree species. The forest canopy is composed of deciduous hardwood species, principally black ash but also green ash (Fraxinus pennsylvanica), yellow birch (Betula allegheniensis), red maple (Acer rubrum), American elm (Ulmus americana), balsam poplar (Populus balsamifera), and quaking aspen (P. tremuloides). The coniferous component is minor and includes a few black spruce (Picea mariana), white spruce (P. glauca), tamarack (Larix laricina), and balsam fir (Abies balsamea). The shrub layer is largely tag alder (Alnus rugosa) with pussy willow (Salix discolor), winterberry (Ilex verticellata), mountain maple (Acer spicatum), and beaked hazel (Corylus cornuta).
Although I have not taken any cores of the trees in the Western Black Ash Swamp the age of the forest can be inferred by the diameter of the trees. In a study of black ash swamps in Carlton County, Minnesota, Kurmis and Kim (1989) reported that black ash trees in the black ash-red maple-American elm association, with a DBH (diameter at breast height) between 20 cm and and 30 cm were between 50 and 100 years old (some were a little older at 120 to 140 years). In a sampling plot in the Western Black Ash Swamp I measured all canopy level black ash and other trees. Of 50 trees measured 18 were black ash with diameters ranging between 10 cm and 36 cm. Seven were between 10 and 18 cm, seven more between 20 and 24 cm, three between 26 and 28 cm, and one at 36 cm. Those between 20 and 24 cm are probably about 80 years old. The larger ones might be almost a century. I also measured all the black ash with Lobaria lichens on them. Three were between 20 and 22 cm, three were between 24 and 28 cm, and six were between 28 and 44 cm. The largest black ash trees are probably at least 80 years old. One tree, not in the plot, has a diameter of 50 cm and it seems very likely it is over 100 years old.
There is very little sphagnum in the Western Black Ash Swamp and generally where it occurs it appears scattered clumps or patches with other mosses. There is one large colony with a more continuous cover of peat mosses in a small level area, possibly a seepage zone, of white spruce, black spruce and balsam fir. Sphagnum species identified are S. palustre, S. squarrosum, and S. teres. The herbaceous layer (see the checklist in this PDF file) contains several grass and small sedge species, mint, bugleweeds, mad dog skullcap, asters, goldenrods, lycopods, horsetails, and other forbs and ferns.
The soils in the Western Black Ash Swamp are shallow muck and mucky mineral with numerous small to large rocks both beneath and visible at the surface. The wetland soils have formed in glacial till and outwash modified by prolonged saturation. These soils and the wetlands on them are not mapped in soil surveys or state wetland maps. The surrounding upland soils are well-drained coarse to fine-sandy loam soils formed from glacial till and outwash derived from Pre-Cambrian age regional bedrock (a hodgepodge of slate, graywacke, sandstone, basalt, gabbro, gneiss, granite, banded iron formation and many other interesting rocks).
Last spring on April 06, 2014 I made a visit the Western Black Ash Swamp to search for Lobaria pulmonaria and L. quercizans on black ash, red maple, yellow birch, American elm, balsam poplar, and quaking aspen. My visit focused on the forested wetland and shrub carr transition zone. I did not find any Lobaria species there although I did find many Physconia lichens similar to the ones in the Black Ash/Alder Zone plus P. detersa. I think that this section of the wetland, which faces east and southeast, is too exposed to the sun. Most of the trees, however, are old enough for Lobaria lichens to have colonized if light and humidity conditions were appropriate. All were heavily colonized by many other species of lichen (a list is in progress).
During treks (it is a 0.8 km walk through sedge marsh and willows one way) on December 24, 2014, January 24, 2015, March 07, 2015, March 10 2015, March 11, 2015, and March 14, 2015 I went further into the Western Black Ash Swamp searching all hardwood species and found several colonies of both Lobaria species. Colonies were flagged, the coordinates taken, and data on lichen size, position and height on tree, and other habitat data were recorded.
There are six colonies each of Lobaria pulmonaria and L. quercizans. All but one Lobaria colony were found on black ash trees with a single small L. pulmonaria found on a red maple (14 cm DBH).
Lobaria pulmonaria Colonies
Of the six colonies Lobaria pulmonaria all but one were found on black ash trees. The other is on a red maple.
Three colonies of L. pulmonaria consist of small thalli about 7.6 cm across. The first (one thallus) is 1.2 meters from the ground on the northeast side. The second (one thallus) is just 0.6 meter from the ground on the southwest side and growing on a thick patch of moss. The third (two thalli) is on a red maple about 1.5 meters from the ground on the southwest side. None bear apothecia but soredia were present on the lobe ridges.
The fourth colony of L. pulmonaria contains six individuals. The first three measured 2, 5, and 7 cm respectively and are about one meter from the ground. Above these are larger thalli measuring about 15 cm across and are probably older individuals. They are located between 3 and 6 meters above the ground on the north and northwest sides. This tree may be the source of all the smaller and presumably newer colonies of L. pulmonaria. These lichens also have abundant soredia but no apothecia.
Colony five consists of 11 thalli. Seven of these are between 1 and 2 cm across and about one meter from the ground on the north and northwest sides of the tree. The pair of thalli are about 3 cm in diameter, one meter from the ground on the north side of the tree. The last two thalli are about 5 cm in diameter, three meters from the ground and on the northwest side of the tree. There are no apothecia.
Colony six has one thallus about 5 cm across and 1.5 meters from the ground on the north side of the tree. There are no apothecia.
Lobaria quercizans Colonies
The six colonies of L. quercizans found are all on black ash trees. The first colony consists of two thalli each about 30 cm across with the central portions apparently eaten by an animal (a squirrel or bird?). They are located on the northwest side of the tree about 2 meters high. The ash tree is about 30 cm in diameter. As a side note L. quercizans is an edible lichen used by the Menomini and other Indigenous Americans as as a restorative medicinal food as noted by Smith (1923) where he uses the synonym Sticta glomulerifera. S. glomulerifera is a synonym for another species of smooth lungwort, L. amplissima which is a European species that is not known to occur in eastern North America but does occur in California and Alaska (Tønsberg and Goward, 2001). L. amplissima and L. quercizans are similar in appearance so it is likely that he merely confused the two species. Also, Sticta and Lobaria are closely related genera and have at times been combined.
The second colony contains one thallus, 30 cm in diameter with a few apothecia, on the east side of a leaning dead black ash tree about one meter from the ground. Although much of it looks healthy the newest portions of the lobes are yellowing possibly indicating disease.
The third colony has three small thalli that measure 7, 10, 12 cm across respectively. They are on the north side of the tree about 2 meters from the ground. None look healthy.
Colony four is on a standing dead ash tree and consists of thallus fragments scattered between 1 and 2 meters from the ground. This tree has several cavities excavated by pileated woodpeckers. There are some smaller thalli near the tree’s base that may be new Lobaria quercizans lichens.
The fifth colony consists of two thalli about 18 cm in diameter and between 3 and 4 meters from the ground on the southwest side of the tree.
The sixth colony is on a fallen ash that has died and is beginning to decay. When the tree was living the lichens were about 1 to 2 meters from the ground and measured between 7 and 15 cm across. Six thalli were found and located on what was the north side of the tree. All the thalli are beginning to die.
On January 24 and 26, 2014 I made additional treks into the Western Black Ash Swamp and the adjacent uplands searching more ash and other hardwood trees for L. pulmonaria and L. quercizans. No new colonies of either species were found on those days but several new colonies of lichens in the genus Pertusaria were. To date three species have been identified as P. ophthalmiza , P. macounii, and P. veluta. Other specimens await identification. European studies (Fritz et al. 2008) suggest that Pertusaria species are more frequent on trees 50 or more years older. Fritz et al. (2008) also noted that the liverwort Ptilidium pulcherrimum and the moss Hylocomium splendens also occur in forests on trees over 50 years old. Both are found in the Western Black Ash Swamp and can be taken as indirect indicators of the forest’s age.
Unknown Pertusaria (?)
Finding Lobaria quercizans in this swamp marks the second known occurrence of the species in Carlton County, Minnesota. Additionally, new colonies of the more common L. pulmonaria were also found and these contain many young individuals indicating a recent colonization. Large thalli of L. pulmonaria are scarce here and have no apothecia. All L. quercizans colonies are large and bear many apothecia. Lobaria are lichens typical of old forests with high humidity. Their presence along with other indirect evidence supports the idea that many of the canopy level trees in this black ash swamp are older than 80 years.
Other lichens were also found including Heterodermia speciosa, Pyxine soredata, Ochrolechia trocophora, Pertusaria velata, P. macounii, P. ophthalimiza, and Physconia detersa and there are many others not yet identified. The terrestrial and epiphytic moss, liverwort, and lichen community appears to be very rich.
Future Work in the Black Ash Swamp and Lobaria and Other Lichen Surveys
In the following months once the snow melts and temperatures moderate I will be making new lichen searches of the Western Black Ash Swamp. There are a number of unusual lichens, mosses, and liverworts on the ash and other trees. Some may be new records for Carlton County, Minnesota, others new population occurrences of species not well known in the state. I will also be mapping the locations and characteristics of the seeps (a project I started a few years ago). Other projects to be conducted over the next few years as time permits will be to continue floristic surveys (including lichens, bryophytes, and hepatophytes), document variations in tree cover density, continue to measure the diameter and height of trees, and map micro-habitats within the wetland.
Next Biodiversity Post- Documenting Local Biodiversity: What Is This Moth?
Brodo, I. M., Sharnoff, S. D., Sharnoff, S. (2001). Lichens of North America. Yale University Press, New Haven, CT.
I actually walk in the woods near my house a few times a week. But the woods on the west side of my property are a real trek at 0.55 km (one-third of a mile) in one direction so I go there only a two or three times a month. There is no trail or path to get there and in the winter one must cross a small stream with sometimes thin ice and then clamber over sedge tussocks and through willow and alder thickets. But it is always interesting even in the dead of winter. Today, the air temperatures were mild and the high reached about 55 F. All week the weather has been warm and what little snow we got this winter is almost gone in the open areas and quickly disappearing in the woods.
On my way across the river I saw two otters out on the ice so I waited a few minutes until they dove back under the water. I usually see where they have been (scat, the remains of crayfish and clam shells) so this was special. Even though it is officially still winter for another nine days some insects and spiders are starting to move about. There are small moths in the sedge meadow and black spiders crawling over the the remaining snow and ice.
I made way across the ice to the other side of the river. There were a few nice surprises. One was finding blue honeysuckle (Lonicera villosa) at the edge of an alder thicket. This is one more piece of evidence that a forested swamp once grew where there are now alders since this Lonicera species is common in rich conifer-hardwood swamps. The forest is making a comeback as many new tamarack, white spruce, balsam fir, tacamahac, elms, red maples, and black ash are starting to emerge from the alders.
Another nice surprise was finding a cocoon which I think may belong to the cecropia moth. There are plenty of its larval host plants available like elm, willow, and paper birch in the immediate area.
Eventually, I got into the woods and began exploring. I set a number of goals for my walk out there including looking for lichens and getting photos of the black ash swamp. I found an interesting pelt lichen (Peltigera) on a fallen fir tree log but have not determined the species yet. I will need to go back and look at the lichen more closely especially at the venation pattern on the underside. At any rate, it is the fourth new Peltigera lichen I have found here.
Further into the woods I saw fresh wolf tracks maybe less than two hours old. That was good to see since these animals are persecuted by too many people around here.
I stayed in the woods for about four hours before turning back. The day was sunny and mild and there was a lot to see and do. And it was quiet except for the pine siskins, nuthatches, chickadees, and the wind through the trees.
I’m still cooking corn bread and getting ready to start a new batch of hominy (this time I think it will turn out perfect!). But I’ve also been working on a several new biodiversity posts. This one documents the discovery of new populations of Lobarialichens on my land.
In 2013 I wrote about the lungwort lichen (Lobaria pulmonaria) that had been growing on the same yellow birch tree since at least 1970 and probably long before then. At the time I reported that it was the only one I had seen on my land. In fact, I have seldom found this distinctive and conspicuous lichen in spite of covering many tens of thousands of acres of forested land from northwestern Minnesota to southern Wisconsin and across the Upper Peninsula of Michigan in the last quarter century.
After writing about the lungwort lichen I wondered if there were other L. pulmonaria lichens on my land. I also I wanted to know more about the habitat where it occurred.
I Search the Tamarack Swamp
The preferred habitat of L. pulmonaria is on the bark of old hardwood trees in humid forests like in the Tamarack Swamp (Gauslla and Solhaug 2000, Brodo et al. 2001, Wetmore 2002). There are a few red maple (Acer rubrum), yellow birch (Betula allegheniensis), and paper birch (B. papyrifera) in the tamarack swamp near the original site. But these are all young trees around 30 to 40 years old so the chance of lungwort lichen growing on any of them is slim. But I decided to exercise all due diligence and last March and April I made a thorough search of the maples and birches. The results were no new L. pulmonaria.
A Micro-habitat in the Tamarack Swamp
There is also a small patch of black ash (Fraxinus nigra) trees in a separate area of the swamp and it was here that I began a new search. The black ash trees are in a tag alder swamp on the north side of the tamarack swamp that I call the “Black Ash/Tag Alder Zone”.
Description of the Black Ash/Tag Alder Zone
The Black Ash/Tag Alder Zone is heavily vegetated with tag alders (Alnus rugosa) and tea-leaf willow (Salix planifolia). There are also blue honeysuckle (Lonicera villosa), winterberry (Ilex verticillata), some Labrador tea (Rhododendron groenlandica) and a few sapling to pole-sized red maple and yellow birch. Parts of this zone are vegtated with sphagnum mosses with Sphagnum palustre being the most abundant species. In between moss hummocks are patches shallow open water and stands of beaked sedge (Carex utricullata). Other herbaceous plants are lake sedge (Carex lacustris), manna grass (Glyceria canadensis), Canada bluejoint grass (Calamagrostis canadense), bugleweed (Lycopus uniflorus), and marsh marigold (Caltha palustris). A full species checklist is here in a PDF file.
Soils in the Black Ash/Tag Alder zone are a black colored mucky peat. The soils in the rest of the swamp where tree cover is predominantly tamarack and black spruce are brown colored woody and sphagnum peat. Much of the year there is standing water between sphagnum moss and root hummocks. A layer of cobbles and stones is present about a third of a meter below the surface at least near the upland and wetland edge.
The Tamarack Swamp is ground water fed and along the eastern edge there is a slow seepage of water that marks the beginning of the Black Ash/Tag Alder Zone. The seepage follows a narrow band starting on the east side and flows west along northeast side of the swamp. Water from the seepage feeds into the area where the black ash and a few small red maples and yellow birch grow among the alders. From there the water moves slowly through more alders and some conifers to a narrow outlet on the west side about 22 meters wide. Then the water flows into an 80 meter long trough (slope 1.66%) that drains into a larger shrub carr and sedge meadow.
The black ash were here when I first arrived to this land in 1970. Some have been here for at least six decades (I counted 60 rings on one fallen tree) and other larger trees may be older. In the last 30 years all the ash have been doing poorly with little new growth, dead tops, scant seed production, and only two seedlings to replace the several trees that have recently died. The few remaining black ash trees are short, about 6 to 7 meters tall, and their diameters are between 7 and 15 cm but none are healthy. A few tamarack (Larix laricina), black spruce (Picea mariana), and balsam fir (Abies balsamea) grow here, too, but frequent wind-throw events prevent the formation of a continuous canopy.
Results of the Search in the Black Ash/Tag Alder Zone
In April last year I started my search of the black ash for more Lobaria. The search resulted in finding two new L. pulmonaria colonies on live trees. Now I knew that there were others of this species present.
But there was an even more interesting and important find. Growing on one ash tree with L. pulmonaria was another Lobaria species. This was L. quercizans, an uncommon species in Minnesota (Wetmore 2002, MN-DNR 2015). This gray-green foliose lichen stood out as different from the other gray and gray-green lichens on the tree. Almost at once I had a strong sense that it was L. quercizans a rare species I’d read about but never expected to find especially in my backyard. I went back later that week and again last December to re-check all the black ash trees in the area. The results were one more L. quercizans and another L. pulmonaria. The L. pulmonaria was on the stump of a wind-thrown black ash tree not noticed earlier in a tangle of alders and is about a foot in diameter, a giant and probably very old. This brings the total to four L. pulmonaria (three on black ash, one on yellow birch), and three L. quercizans, all on black ash, in the tamarack swamp.
In addition to the new Lobaria pulmonaria and L. quercizans, other lichens were found on the black ash trees. Among those identified are Cladonia fimbriata, Graphis scripta, Heterodermia speciosa, Hypogymnia physodes,Lecanora thysanophora, Lepraria lobificans, Myelochroa auralenta, Ochrolechia trochophora, Peltigera sp. (1 unidentified species), Pertusaria velata, Phaeophyscia rubropulchra, Physcia ascendens, Physconia spp. (2 unidentified species), Punctellia appalanchensis, and Pyxine sorediata.
Ochrolechia trochophora and other species
Lobaria quercizans and L. pulmonaria description, habitat, and distribution Lobaria quercizans is, likeL. pulmonaria, a species of old forests. WhileL. pulmonaria has a very widespread range from North America to Europe, Asia, and Africa,L. quercizans is restricted to parts of east Asia and the eastern North America. In the United States it occurs along the Great Lakes from Maine to Minnesota, south from Michigan to Kentucky and then northeast through the Appalachians. In Canada L. quercizans occurs in New Brunswick and Newfoundland and then west to the southern parts of Ontario and Quebec. (Brodo et al. 2001, Brodo et al. no date, Wetmore 2002)
L. quercizans is most often found on sugar maple but also grows on red maple, black ash and old quaking aspen trees. It differs markedly in appearance from L. pulmonaria. The thallus (lichen body) is gray when dry, green when wet, younger portions of the thallus lobes are smooth but gradually become wrinkled with parallel ridges, reddish-brown apothecia (spore producing organs) are frequently produced and are not restricted to the thallus margins, and soredia and isidia (vegetative propagules) are absent. Pycnidia (asexual fruiting bodies) are frequent. The upper cortex reacts K+ yellow and the medulla reacts K+ orange, KC+ red, C+ pink.
The large flat gray thallus of L. quercizans resembles some species of shield lichen such as some Parmelia (shield-lichens) but its lower surface is light brown and tomentose (a wooly growth of hairs or fuzz). Shield lichens are black or white below, not tomentose, and attached to the substrate by black rhizines (root-like outgrowths). The lichen Punctellia appalanchensis is similar but has prominent white markings on the thallus. (Brodo et al. 2001)
The thallus of L. pulmonaria is brown to olive brown in its dry state but bright green when wet. The upper thallus surface is ridged and pitted above. Below it is covered in a light brown tomentum. The once to twice branched lobes measure 8-30 mm across and to 7 cm long. There are few apothecia and these are found near the thallus lobe margins but soredia are common on the thallus lobe margins and the ridges. The medulla reacts K+ yellow to red. (Brodo et al. 2001, Brodo et al. no date)
Conservation Concerns Lobaria pulmonaria is widespread in its global distribution occurring in forests of the humid north temperate and boreal regions, and cooler montane regions of the tropics (Brodo et al. 2001). While apparently in no immediate danger in the United States and Canada, the situation for L. pulmonaria is less favorable in many parts of Europe where it is declining in some areas and where some local extinctions have occurred. Air pollution from sulfur dioxide (Wetmore 1995, Ockinger et al. 2005), the loss of mature forests and habitat fragmentation are responsible (Erdman et al. 2008, Ockinger and Nilsson 2010, Ju¨riado et al. 2011, Ellis 2015).
In North America L. quercizans is largely restricted to the Appalachian and Great Lakes regions with additional populations in eastern Asia (Brodo et al. 2001, Wetmore 2002). In several parts of the United States and Canada L. quercizans is threatened (whether officially recognized or not is doesn’t matter) at its range periphery and in other parts of its range where old forests are being logged (Wetmore 2002). Like L. pulmonaria, it is sensitive to air pollution and prefers humid environments (Wetmore 1995, Wetmore 2002).
Both species are sensitive to increased light and lowered humidity (Gauslla and Solhaug 2000, Wetmore 2002). As such they are dependent on old forests with closed canopies for best growth and survival. Clear-cutting and selective cutting (high grading) remove closed canopies or create large openings that can negatively affect them (Wetmore 2002, Erdman et al. 2008). As L. pulmonaria and L. quercizans are also long-lived species conversion of forests to short-rotation even-aged stands reduces opportunity for suitable substrates on which they can grow (Wetmore 2002, Erdman et al. 2008, Ju¨riado et al. 2011). The presence L. pulmonaria and L. quercizans in a forest are an indication of the forest’s age and its environmental stability (Wetmore 2002, Ju¨riado et al. 2011).
Next Biodiversity Post- Documenting Local Biodiversity: Another Lungwort Lichen, Part 2
Brodo, I. M., Sharnoff, S. D., Sharnoff, S. (2001). Lichens of North America. Yale University Press, New Haven, CT.
Brodo, I. M., Cameron, R., Andrachuk, H., and Craig, B. (no date). Identifying Lichens of Nova Scotia. Ecological Monitoring and Assessment Network (EMAN) Coordinating Office, Environment Canada
Edman M., Eriksson, A., and Villard, M. (2008). Effects of selection cutting on the abundance and fertility of indicator lichens Lobaria pulmonaria and Lobaria quercizans. Journal of Applied Ecology 45:26–33.
Ellis, C. J. (2015). Ancient woodland indicators signal the climate change risk for dispersal-limited species. Ecological Indicators. Vol. 53, June 2015, pages 106 -114.
Gauslaa, Y. and Solhaug, K. A. (2000) High-light-intensity Damage to the Foliose Lichen Lobaria pulmonaria within a natural Forest: The Applicability of Chlorphyll Fluorescence Methods. Lichenologist 32(3): 271-289.
Ju¨riado, I., Liira, J., Csencsics, D., Widmer, I., Adolf, C., Kohv, K., Scheidegger, C. (2011). Dispersal Ecology of the Endangered Woodland Lichen Lobaria pulmonaria in Managed Hemiboreal Forest Landscape. Biodiversity Conservation (2011) 20:1803–1819.
Ockinger, E. Niklasson, M. and Nilsson, S. G. (2005). Is Local Distribution of Lobaria pulmonaria Limited by Dispersal capacity or habitat quality? Biodiversity and Conservation 14: 759-773.
Ockinger, E., Nilsson, S. G. (2010). Local Population Extinction and Vitality of an Epiphytic Lichen in Fragmented Old-growth Forest. Ecology (2010) 91(7):2100-2109.
Wetmore, C. (1995). Lichens and Air Quality in Lye Brook Wilderness of the Green Mountain National Forest, Final Report. USAD-Forest Service Green Mountain National Forest and Northeastern Area State and Private Forest Health Protection. Contract 42-649. 40 pages.
Wetmore, C. (2002). Conservation Assessment for Lobaria quercizans Michx. Prepared November 2002 for USDA Forest Service, Eastern Region. 18 pages.
The lichen in the photo above is like an old friend of mine. I’ve known this lichen since 1972 when I first found it growing on a yellow birch tree in the conifer swamp in the southeast corner of my land. It is called Lobaria pulmonaria after the lobed thallus with its raised network of ridges that resemble lung tissue.
After all the years that the Lobaria has been growing on the bark of the yellow birch it has not gotten very large. Normally, L. pulmonaria grows in on the bark of maple, aspen, beech, ash and other trees with tight bark. But birches have exfoliating bark and as sections of bark peel off they take some of the lichen with them. Thus, it never is able to grow very large on this tree. It is in a good location though, on the north side of the birch in a moist and humid conifer swamp. I check on it at least twice month to be sure it is alright. This is important as it is the only L. pulmonaria on any tree on my property and in the immediate area that I have found. But I haven’t checked every tree either.
Lichens are not plants or even single organisms but symbiotic associations of two or more organisms. The first is a fungi most commonly a species of ascomycetes, the “sac fungi”. Almost half of the 30,000 species of ascomycetes are known to form lichen associations. In a few lichens fungi from the Basidiomycetes (mushrooms) are involved.
The second symbiont in a lichen association is a photosynthetic organism called the “photobiont”. Most often the photobiont is an algae usually from the genus Trebouxia although in Lobaria the green algae is a species of Dictyochloropsis. Other algae genera in lichen associations are Coccomyxa, Stichococcus, and Heteroccus. Prokaryotic cyanobacteria from the genus Nostoc also occur in many lichens.
Lobaria lichens are composed of an ascomycete, a green algae (Dictyochloropsis or Trebouxia), and a cyanobacteria (Nostoc or Scytonema). In L. pulmonaria the photobionts are Dictyochloropsis and Nostoc. Lobaria are indicator species, that is, species with particular ecological tolerances (or intolerances, as the case may be) and so can be used to assess the quality of an area. Healthy growth of Lobaria indicate old forests with high humidity and clean air. Cyanobacteria like Nostoc can fix atmospheric nitrogen. In forests with an abundance of Lobaria and other lichens with cyanobacteria their contribution to the nitrogen budget can be substantial. In one study of L. oregana in old growth Douglas fir forests nitrogen fixation was estimated at 3.15-3.5 kg/ha/year.
L. pulmonaria is not the only lichen growing on the yellow birch tree. There are seven, possibly more, other lichen species. Six of these are Physconia sp., Pyxine sp., Myelochroa auralenta, Heterodermia speciosa, Parmelia rudecta, and Phaeophyscia rubropulchra all so-called foliose lichens.
Brodo, I. M., S. D. Sharnoff, and S. Sharnoff. 2001. Lichens of North America. Yale University Press, New Haven, CT.
Denison, W. C. 1979. Lobaria oregana, a nitrogen-fixing lichen in old-growth Douglas-fir forests. Pages 226-275 in Gordon, J. C., C. T. Wheeler and D. A. Perry., editors. Symbiotic nitrogen fixation in the management of temperate forests. Forest Research Laboratory, Oregon State University, Corvallis, OR.