So I took Sunday off from garden work to canoe across the marsh and take a walk on the woods in the west side of my land. It had been almost a month since my last visit and I wanted to see how things had changed during that time. The forest floor where the white pines, quaking aspen, and white spruce grow is now green with a thick carpet of stalked sedges, mountain rice grass, false melic, woodland anemones, Mayflowers, bunchberry, gold-thread, twinflower, princess pine, yellow vetchling, dewberry, twisted stalk, starflower, big-leaf aster, ferns and violets. Scattered here and there among all this green are pale yellow stalks of the yellow coralroot orchid (Corallorhiza trifida) an achlorophyllous plant that obtains its nutrients as a parasite on the mycorrhizal fungi of tree roots.
There were some strange mushrooms such as Gyromitra korfii (false morel) growing on rotted spruce stumps and logs. I even found a real morel (Morchella angusticeps) under some black ash trees at the wetland/upland interface. I was hoping to find the devil’s urn (Urnula craterium) fungus among the ash but no such luck this time. Also along the interface were large patches of wild ginger (Asarum canadense) a herbaceous plant with kidney-shaped leaves and fragrant pungent rhizomes. Fresh rhizomes can be candied and dried rhizomes can be brewed into a spicy beverage. The thick fleshy flowers of wild ginger are unusual and look a bit like three-sided red bells with wiry tassels.
Over in the black ash swamp I investigated the many seeps that are there. Marsh marigold, a seep indicator species, is everywhere water seeps from the ground. Although it is not as abundant as I had expected it is still very common and I saw many small plants still too young to flower. Growing with the marsh marigold were other seep indicator species: marsh blue violet (Viola cucullata), golden saxifrage (Chrysospleniun americanum), swamp saxifrage (Saxifraga pensyvanica), golden ragwort (Senecio aureus), and bittercress (Cardamine pensylvanica).
There was plenty of wildlife, too. I saw fresh timber wolf scat and a veery and her clutch of blue eggs in a nest on the ground. Many birds were singing although I was only able to identify ovenbird, oriole, and white breasted nuthatch. I’m just not that good at recognizing bird calls (yet). And I saw a small black and white moth. I was hoping it was the scarce infant moth. I followed it for about 30 feet until it landed on a tree trunk and tried to get a photo. Its out of focus but was enough for me to identify it as the white striped black moth (Trichodezia albovittata). Their larval host plant is jewelweed (Impatiens capensis and other Impatiens species) of which there is plenty in the ash swamp.
In most years, this forest pond is filled with water. Sometimes it is almost three feet deep, but usually it is about two feet. When it is flooded the pond is alive with the breeding calls of wood frogs, spring peepers, and chorus frogs. Masses of eggs soon hatch into thousands of black tadpoles. There are pill clams (Sphaerium) in the silt and tiny Planorbula snails gliding over twigs and moss searching for algae to eat. Fairy shrimp, ostracods, and copepods swim in the placid waters. Sometimes mallards and black ducks stop in.
But not this year. We are in a drought. Snowfall was below normal and spring rains have been scant. Warm temperatures and strong winds have also taken away moisture. Unless there is rain soon and enough to keep the pond filled until July the frogs will need to find other places to breed. The small crustaceans, mollusks and other invertebrates will need to wait out the drought perhaps until next spring.
Cycles of wet and dry years are not uncommon here and this pond has been through drought before. While the pond is dry sedge and grass will expand a little and some mosses will die back. The tiny invertebrate animals will remain dormant as eggs and cysts. Some may not survive and will disappear from the pond until, by chance, more come in on the feathers of a duck.
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.
I first saw the great snakeskin liverwort back in the spring of 2003 in my west 40. A few years ago while mapping seeps in the woods there I came across what was probably the original plant and several other large colonies growing in around seeps. The flora and geology of freshwater seeps is of particular interest to me.
The great snakeskin liverwort (Conocephalum conicum) is probably one of the easiest liverworts to recognize. Its shiny, dark green to yellow-green, large thallus, 16 to 20 mm wide and 12 to 25 cm long, with large coarsely hexagonal scales, each with a raised pore, across the surface are distinctive characteristics and easily observed. A line of two or three rows of parallel linear scales form a sort of mid-vein down the middle of the thallus. On either side of this row are scales diverging obliquely from the middle out to the edge. The thallus forks periodically giving the whole plant a branching appearance. The underside of the thallus is covered with numerous purple rhizoids that anchor it to soil and other moist substrates.
Having said that, in light of a new species delineation I now have reasons to doubt my original identification but the matter cannot be settled yet (see below “Another species of Conocephalum?“).
Habitat and Plant Communities
The great snakeskin liverwort is distributed across the northern hemisphere except in the extreme Arctic and grows in moist shaded places or sometimes full sun along creek banks, in seeps, and on moist rock outcrops where soil and water chemistry are mildly base-rich to neutral.
The specimen pictured above grows along the margins of and on high spots in a slow seepage that periodically dries up during the summer. It is located in mixed deciduous-coniferous forest composed of black ash (Fraxinus nigra), aspen (Populus tremuloides), red maple (Acer rubrum), yellow birch (Betula allegheniensis), white spruce (Picea glauca), beaked hazel (Corylus cornuta), mountain maple (Acer spicatum), and tag alder (Alnus rugosa). Associated bryophytes seen with it are Rhizomnium punctatum, Thuidium delicatum, and Climacium dendroidium. Associated vascular plants include golden saxifrage (Chrysosplenium americanum) and naked miterwort (Mitella nuda). Soils where the seeps are located are glacial outwash in origin with a fine sandy loam texture and contain quartz, feldspars and other alumino-silicate minerals from basalt, gabbro, slate, sandstone, graywacke, banded iron formation, gneiss, and granitic rocks. In general, the soils tend towards an acidic pH and are low in calcium carbonate but soil and water chemistry in seeps can be radically different from the surrounding upland soil.
While often eaten by slugs and snails liverworts, or for that matter mosses and lichens, are not usually thought of as host plants for moth and butterfly larva. In the case of the great snakeskin liverwort there is a group of small, primitive moths, the Micropterigidae, whose larva feed almost exclusively on it.
When the thallus of Conocephalum is gently rubbed between the fingers a fragrant mushroom odor is emitted. The odor is from volatile aromatic terpenoid compounds which are being investigated for potential medical uses.
Another species of Conocephalum? Conocephalum conicum was for a long time thought to be the only species in the genus Conocephalum and the only member of its family Conocephalaceae. Recently, a new species has been identified and named Conocephalum salebrosum (Szweykowski et al. 2005). It differs from C. conicum on several characters. After reading Szweykowski et al. (2005) and Long (2010) it appears that C. conicum may be restricted to Europe while C. salebrosum is more widely distributed. So who knows? Perhaps the great snakeskin liverwort growing in the seeps in my western 40 are actually C. salebrosum. Then again it could be C. conicum. The answer to this will have to wait until April or May when the snow melts and ground thaws. Then I will be able to collect good specimens for inspection. When I find out I’ll post an update.
Next biodiversity post: Another lungwort lichen, Part 1
Long, D., 2010. Conocephalum conicum/salebrosum, Great Scented Liverwort/Snakewort in Mosses and Liverworts of Britain and Ireland – a field guide. Atherton, I., Bosanquet, S., and Lawley, M., editors. 2010. British Bryological Society 2010. Latimer Trend and Co. Ltd, Plymouth, England.
Schuster, Rudolf M. 1953. Boreal Hepaticae, A Manual of Liverworts of Minnesota and Adjacent Regions. The American Midland Naturalist (Vol. 49, No. 2, March 1953).
Szweykowski, J., Buczkowska, K., and Odrzykoski, I. J. Conocephalum salebrosum (Marchantiopsida, Conocephalaceae)- a new Holarctic liverwort species. Plant Systematics Evolution (Vol. 253, 133-158).