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 Lobaria lichens 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.
Lobaria quercizans and L. pulmonaria description, habitat, and distribution
Lobaria quercizans is, like L. pulmonaria, a species of old forests. While L. 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)
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.
Minnesota Department of Natural Resources. Species Profile Lobaria quercizans Michx., Smooth Lungwort. (Retrieved on February 01, 2015.)
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.