Deserts and northern latitude terrains seem to be where most of the world’s lichens live. During my visits to the arid Sonoran desert, desert lichens have my attention. I’ve always loved deserts. Mystery and history sum it up. Desert land is the bones of the earth exposed; rock in endless arrangements and forms that are invisible in vegetation covered lands tell of how the earth has moved and moved, and moved again. Earth rises, sinks, slowly flows from one place to another, melting and cooling in an endless cycle. In this part of the Sonoran desert, the geology in some mountain areas is very complex because of all the different processes and movements over time. Geologists call one mountain range here the ‘Tucson Mountains Mess’, and it is a mess. All sorts of rocks are mixed together in improbable layers and configurations. I often stand in one spot and pick up 15-20 different types of rock without moving a step.
All these rocks were made in a different place, in a different way and at a different time from each other, but they all ended up on the top of the ground in the same place. Some geological processes are still not well understood, and one of the mysteries is how some rocks got in between other layers or areas of rocks that have nothing to do with each other.
The first book about deserts that influenced me was In_the_Deserts_of_This_Earth by Uwe George, a German naturalist. He described stones in the desert covered with what is called ‘desert varnish’, a thin layer of red or black that is from metallic oxides migrating to the surface of rocks.
It was long believed that weathering caused the varnish to form. Israeli scientists were studying the chemical composition of desert stones with desert varnish on them, when they accidentally found that the stones gave off carbon dioxide at night, when covered with dew, and reversed the process in the day, taking in carbon dioxide and giving off oxygen. The process stopped when the sun dried the dew. The rocks were photosynthesizing. Under magnification, the stones were found to be covered with many forms of life; algae, bacteria, fungi and of course our little friends the lichens. It was a microforest, invisible to the eye. While photosynthesizing, these life forms were removing minerals from the dust in the air, fixing them to the surface of the rock and changing the surface of the desert.
Wolfgang Wunderlich, a German geologist, studied these microflora in the Negev desert in Israel and found that the various species of bacteria and lichens were responsible for transforming the metallic oxides from the air and in the rock to the surface of the rock, and so were instrumental in creating the ‘varnish’, as well as photosynthesizing, which changed the chemical structure and composition of the rocks and the surface of the desert. A more complete explanation of how lichens and bacteria make desert varnish can be found in papers from https://www2.palomar.edu/ university published papers.
An excerpt from: https://www2.palomar.edu/users/warmstrong/pljan98.htm#Introduction describes the process of making desert varnish:
“One of the most remarkable biogeochemical phenomena in arid desert regions of the world is desert varnish. Although it may be only a hundredth of a millimeter in thickness, desert varnish often colors entire desert mountain ranges black or reddish brown.
Several genera of bacteria are known to produce desert varnish, including Metallogenium and Pedomicrobium. They consist of minute spherical, rod- shaped or pear-shaped cells only 0.4 to 2 micrometers long, with peculiar cellular extensions. In fact, the individual cells are smaller than human red blood cells which are about 7.5 micrometers in diameter. Because of the radiating filaments from individual cells and colonies, they are called appendaged bacteria. All living systems require the vital energy molecule ATP (adenosine triphosphate) in order to function. In our cells ATP is constantly produced within minute bodies called mitochondria. As electrons flow along the membranes of our mitochondria, molecules of ATP are generated. The electrons come from the breakdown (oxidation) of glucose from our diet. Although varnish bacteria do not have mitochondria, they do have a similar inner membrane structure through which electrons flow to generate ATP. However, in varnish bacteria the electrons come from the oxidation of manganese and iron rather than glucose. Herein lies the marvelous adaptive advantage for producing a layer of black and red varnish on desert boulders.”
In an earlier post, there is an image of lichen buried inside rock. They are only millimeters below the surface but that is enough for them to do their work of changing the rock and bringing nutrients to the surface that are the basis for the development of all other plants.
Weather does play a part in bringing the metallic substances to the rock surface, but lichens and their companions do a lot of the work when they are present. Lichens, in a healthy landscape, cover about 8% of the land surface, so they instigate a significant amount of the chemical interactions on earth. Other than changing the rock itself, lichens fix up to 20% of the nitrogen in the soil.
What looks inconsequential to us as we walk across the ground, whether in the forest or in the desert, is actually a delicate and intricate web of life that literally keeps the earth from blowing away and creates the nutrient chain that supports the whole Web of Life. If it sounds crunchy or you feel little things breaking underfoot, you are walking on a living, working part of the environment that is unnoticed but essential. Please stay on the trail and protect the biofilm. The life crunched underfoot will take decades to regrow.
If you carry a hand lens, you can stop once in a while (a very good idea anyway), get down on your hands and knees and look around through the lens. Besides being able to see the lichens in detail, you might find other mysteries and wonders.
That’s just a few of the surprises found on a trail through that barren looking stretch of gravel. Wherever you are, stop and look down once in a while, get close, and then use the magic key of the hand lens to enter the miniature forests underfoot. There’s always more going on than noticed at first glance.
Please remember, when you are exploring to stay on the trail. Learning to walk on the living layer of biocrust without killing it is a skill that takes time and attention. Here’s a friendly challenge: spend one season of hiking observing everything possible from the vantage point of standing on the trail. Closer observation leads to realizing you will never see everything that is there! No need to wander off trail to find something new.
Thank you for wandering in Lichen Land with me. Please share and like this blog to help lichens become a familiar and valued part of how we understand our Life Support System.
The world is changing in many ways, and one of them is our human awareness of the kingdom of Fungi. We are increasingly aware that fungi, in many forms, is involved in all of life. From wine and beer to bread to medicine to the health of the soil we grow our food from, fungi are essential for all the rest of life. Now we are renewing our knowledge of life to include fungi. ‘Flora, fauna, and fungi’ is much more accurate than ‘flora and fauna’ to describe life on Earth.
For several years I have been considering and wondering about lichens. Lichens always are partly formed by fungi, and they are different from other life forms. Recently several people have written and spoken about fungi, including lichens, giving both the scientific community and the average person a very different understanding of what fungi are and what fungi do in the living world.
Lichens are just one of many forms fungi take to do their work in the world. Micro-rhizome networks that are everywhere the soil is healthy have been almost unknown to humans yet are vast, complex and have many functions.
I believe humans will continue to adjust their concepts of how life is arranged on Earth. Beyond fungi, the world is filled with archae https://en.wikipedia.org/wiki/Archaea, and protists https://en.wikipedia.org/wiki/Protist and more creatures than we can imagine. Humans are a minuscule part of the vast diversity of life. We do not have a complete knowledge of the insects, animals, or plants, but there are many more microscopic forms of life than there are visible forms.
If you can’t be in the woods meeting fungi in person, start an exploration of what is being learned about fungi with Merlin Sheldrake’s Entangled Life. Once the door to the mysteries of the Fungi Kingdom opens, you will find more to explore. Many people have been quietly learning about fungi, and now their ideas and work are in print https://www.goodreads.com/shelf/show/fungi. Some of you may have seen the beautiful movie https://fantasticfungi.com/ .
News sources run feature stories about the Fungi Kingdom, https://www.theguardian.com/commentisfree/2021/nov/11/fungi-earth-secret-miracle-weapon. Humans are voraciously collecting and consuming the fungi in forests across the continent. Creative ideas about using fungi for clothing, packaging, new medicines, and more are being explored.
Some of our knowledge of fungi is very ancient. The ‘Iceman’ https://en.wikipedia.org/wiki/%C3%96tzi who died 5,000 years ago and was preserved in ice in the mountains on the border of Italy and Austria was carrying a piece of fungi with a string through it. The fungi is known to have medicinal properties, and could also be used for making fire.
There may be many kinds of fungi for every plant and tree you see. Under the ground, inside the roots, and through bark fungi weave a vast and complex network supporting all other life. Think about the fungi as you walk along, and you will begin to notice them, popping up everywhere.
Fall is a good season to find many types of fungi. The leaves are gone, the weather is still mild and many fungi appear. I’ve found Conopholis americana (squaw root) in large patches in the fall.
Many more people are harvesting mushrooms now than ever before. Many areas have damaged soil, and many fungi are becoming rare or missing due to our taking so many from their place in the land. Please consider this if you are ‘hunting’ mushrooms. To remain viable most of the fungi need to be left in place. You may take what seems sustainable, but how many others will be taking from the same area? Good stewardship considers the situation for the plants or creatures in question, beyond personal expectations.
Take more pictures, take fewer fungi from the forest. Enjoy their beauty, sample a few, take a picture. They are busy working to keep the whole forest healthy for all of us.
Sea slugs (marine gastropods) are one of my all-time favorite creatures. A nice surprise this morning was learning that some of them are similar to lichens, another of my favorite Kin. How could a sea slug be similar to a terrestrial based lichen? Both can photosynthesize! Humans wonder at lichens’ unique status as a combination of two (or more) very different life forms that join to make a completely different life form. The fungus uses the energy produced by the bacteria or algae partner. Some sea slugs incorporate chloroplasts into their bodies from algae they eat. The chloroplasts produce sugars that the sea slug uses for energy.
There are some lucky people who spend their lives studying sea slugs. http://seaslugforum.net/showall/elysatro They are a quiet bunch of scientists and naturalists, probably because staring at sea slugs is mesmerizing. Sea slugs seem to be as varied as lichens in shapes and colors, and are one of the small beings that do much to keep the Web of Life woven together, as lichens do.
Lichen and sea slug shapes are similar too, for some species.The similarity between Elysia sp. and Peltiger sp. is especially striking.
Humans have known about sea slugs using algae photosynthesis after eating the algae for many decades, but recently sea slugs were in the news because a Japanese scientist noticed one of them had lost her head. The body and head were separated, and the head was acting quite unconcerned and quite alive. Within a short time, the separated head had regrown a complete new body. Humans are guessing that is done to avoid parasites. The decapitated-sea-slugs also were ones that incorporated algae photobionts, so that information came to my attention while being amazed about the rearrangement of body parts.
All this strangeness, to us, opens many paths to new understanding about the world we are a part of but often so separate from. Each ‘fact’ we ‘know’ is one small piece of the endlessly intricate world that comes to our attention, but is never the whole story. Now when I visit Peltigera at Site 4 on our Kickapoo Valley Reserve Lichen Trail (the Wintergreen Trail) they will remind me of their distant Kin, far away in a shallow sea, with wavy green, brown and yellow bodies full of algae, so similar to the lichens here on a rock in the middle of the continent.
Thanks for sharing the exploration. Please share this blog with others, to make more friends with lichens.
What makes a ‘discovery’? Recently a lichen species was discovered, in a digitized collection of lichens that had already been collected and misidentified in the past. The digital databases for scientific collections of field samples allow researchers anywhere in the world to explore samples of lichens, and add new information learned since the time the specimen was collected.
I apologize for not providing an image of the new lichen species; I can’t figure out how to manage some of the new aspects of this blog. However, the lichen image above is one of my ‘discoveries’. It is new to me; a discovery made on a slow mosey across a gravelly, cactus and creosote filled flat below Picacho Peak on a warm February evening. Finding a lichen I’ve never seen gives me all the good feelings of discovery; it matters not one tiny bit that others may have already looked at and identified this lichen.
The beautiful cactus above is about two inches tall, seen through a hand lens. This is the first rainbow hedgehog cactus I’ve found and it is a beauty. Unlike many of her kind, there are no pinkish bands of color, only the lace-like white net of spines. Accidentally finding this cactus while looking at lichens in a small rocky outcropping was the best moment of a day filled with excellent sightings and discoveries in a new place. I wonder how many other people wandering very close by on a well used trail have ever seen this tiny beautiful cactus. This was a discovery for me that feels very special.
The black lichen in the above image was a flat dark crust on the rock until I took a look through the hand lens. A multitude of tiny, leafy layers appeared, some with mahogany colors and some with pale edges. Neighbor to the hedgehog cactus, and part of the miniature garden that flourishes at the edge of a busy hiking trail, this lichen and so many others sharing the boulders scattered through the forest are easy to discover by anyone. Slow down, stop for a while and look around. Curiosity is the most effective ‘tool’ for discovering something new.
While idly wandering across gravel flats at Picacho Peak, wondering what might be on seemingly empty ground, I found not only several extremely tiny lichen colonies (see first image), but also found translucent, pale ants making mud tunnels the size of matchsticks, pack rat dens, bird nests, a butterfly new to me, and watched ravens play games with twigs on top of a saguaro. Lichens led me to everything else.
It doesn’t matter what interests you. Everything you find with curiosity becomes new. No matter how many times a familiar lichen is seen, or a bird sighted that you’ve come to overlook because they are so common, there is something new to learn. Discovery doesn’t only happen far away, on Mars or in a distant jungle, it happens in our own backyards and on our favorite walking trails.
I love lichens because their tiny size and inconspicuous ways encourage a slower, more careful observation. Noticing Lichen’s neighbors becomes easy, and before you know it, the forest or meadow is full of color and life you never noticed before. Discovery is not only finding what has never been known by humans, discovery occurs whenever we recognize something amazing or beautiful about the world around us. So next time you are out for a walk, be curious!
For some time lichenologists have known of two species of lichen that are made of the same algae and the same fungi partners, but appear very different. One has vulpinic acid, which makes the lichen bright yellow, the other is dark brown. Recently scientists began looking for more than one algae species in these lichens and found a mystery resident ; a basidiomycete yeast that lives in one species but not the other. Sorting through all the possible partners in a lichen seems daunting, but these scientists are up to the task. They hope to be able to induce lichen to form in vitro, so they can study up on some of their questions without collecting lichen from the wild. Did you know that lichen will not create themselves in an artificial environment? They know the difference.
Take a tour of beautiful lichen pictures while pondering whether those two lichens, one bright yellow and one brown, are really two separate species, and whether there could be more residents in any of those colorful Tiny Ones than we think, and whether they could be up to other behaviors and actions that we have no idea about yet.
It’s hard to believe that a living being that holds so still can be doing so much! Sequestering nitrogen from the air, absorbing poisons from our air pollution, making nutrients available to the trees they are attached to, making soil out of rocks, providing medicine for birds and animals in the form of antibiotics that the lichens make, insulating nests and dens, and much more. Lichen continue to quietly go about their work in the world, so slow down on your next walk in the woods, and look for the Tiny Ones on tree trunks and rocks. Put your ear down close to the ground or the bark and listen. Take a hand lens, and look closely. What’s going on?
Let me know what you find!
I am sitting on a carefully checked rock (cactus spines? rattlesnake?), munching on lunch and letting my eyes focus on the rocks that make up most of the surface of the earth here in this dry arroyo. Two friends and I are spending the day meandering with the water way, smelling and watching and feeling our way into a tiny part of this lush land.
When we pass through this desert in a car, we notice nothing. When we hike a trail at our usual rapid and noisy pace, we notice some of the larger, most unusual residents such as the iconic Saguaro cactus that everyone recognizes. If you are very lucky and observant you may see a roadrunner scoot between the cactuses. But there is more here, more than you can imagine.
I love lichens for many reasons, and so will begin telling of desert wonders by introducing you to a very few of the lichen residents. For they are one of the foundations of all life in the desert.
This blue green foliose lives near the floor of the arroyo, so when water moves through from the summer storms it probably gets very wet. Otherwise life is either very hot and dry or quite cold on this rock. These lichens hold moisture, provide food and shelter and add nitrogen to the land, and moderate surface temperatures, just as they do in the greener hills of the midwest. They help form the biofilm crust that makes a healthy desert ground surface.
Hidden in the lichens and small plants that grow in rock niches are insects, essential for bird and reptile residents. Hawks, owls and small mammals eat the birds and lizards, and they support the coyote, fox and larger animals. All these animals fertilize the land and leave bones, fur and other inedible parts of their meals to return to the soil, replacing nutrients, and so each resident provides something essential for others in a close web of cooperation.
This moss glows with silver light; it drew our attention from quite a distance away. Around the edges were small crustose lichens. (My photo of them was blurry so we can’t see them, sorry. Cell phone cameras are useful but have big limitations that I am not able to overcome.) Since moss prefers less harsh sunlight and more moisture than many lichens, especially the crustose lichens, there are fewer mosses in the desert. This moss is dry now, but turns more green when watered. Often lichens that are dark colored or black have cyanobacteria that give them the dark color. What causes the moss’s dark color? This is the largest patch of moss I have seen so far. Usually there are only small areas of moss in somewhat shady areas. This moss gets a lot of sunshine.
As we munch through our lunch, we notice many birds flying back and forth across the arroyo. There is much twittering in the bushes. The more we look the more birds we see. We are sitting very close to a tiny water hole, and that is why the birds are gathered here.
This tiny puddle and the damp ground around it supports a great many birds, animals, insects and plants. The water is from a rain two days before; there is probably less than a gallon of water here now. Soon this water will be gone but for now it draws dozens of birds and other residents. We see verdin, rock wrens, black phoebe, gila woodpecker, warblers and more. Ants trail across the sand, bees by the hundreds drink from the damp places, butterflies too. Most need some of the water, but it is also a place where many find a meal.
How many species of lichen can you find in the photo above? There are quite a few! This picture shows an area of about 6 inches of rock. Each lichen has a different chemical composition, and may have a different bacteria partner.
The Sonoran desert has over 2,000 species of plants, and over 1,000 species of bees. One hundred species of reptiles here live nowhere else in the world. This bare and harsh looking land is a rich and complex world. Fragile to some stresses, yet resilient and flexible in many ways, the plants and animals of the desert share the lichen’s long adaptation to not only a very hot land, but a home that also is very cold, very dry and very wet at different times.
Below is a desert fern; its leaves are hard, built to resist losing moisture.
The fern is living in a bed of moss, and within the moss are tiny lichen. Lichen surround the moss, in the cracks of the rock. Eventually the moss and fern will go and larger plants take root.
Each time I see a different resident of the desert, I think about what relationships that resident has with any other being nearby. Some relationships are between residents and those who are only here a short time, such as that of the Ocotillo and hummingbirds. Ocotillo blooms in the spring when the hummingbirds that are migrating pass through the area. Nectar from the flowers may be the only food these long distance flyers have. Ocotillo blooms do not depend on rainfall as many other plants’ blooming time does. What conversations have been going on between hummingbirds and ocotillo, for time beyond human understanding, to develop this delicate dance that both support and both benefit from? This is the ever-present story of the desert, and every place on earth, but in the desert there are few or no backup options if one partner fails to participate. Over and over, each animal, plant, insect, fungi and lichen here have a similar story of mutual responsibility and benefit.
A beautiful rock in Sabino Canyon, that tells a complex story about what went on here over a very long time. But hidden in the cracks and shadows is another story; that of the life that begins with tiny spores, isidea and soridea of lichens. Move close, get out your hand lens and look at the rock. There, almost invisible, are the beginnings of a lichen forest. Many years from now the rock may present a different color, then even later, the shapes of crustose lichens will appear fully grown and visible. Insects and birds and lizards and mammals will benefit in many ways, and life will continue in the desert canyon.
Lunch is over, but our walk is not, so my friends and I will leave you, to wander farther up the arroyo. Thanks for joining us!
(Answer to ‘How many lichen species in this picture?’ = I count six! Do you see more?)
Disclaimer: All identifications are tentative. Lichens are very hard to identify, I am not an expert, and my focus is relationships, beauty, and the whole of life around the lichens. If you know what a lichen’s name is, please let me know.
Remember to Look for Lichens!
As in any well done science work, new information that can be verified may change our understanding of the world. We can only learn ‘the next step’, we can never completely know the depth and complexity of the world from any one perspective. And so now lichenologists have found something new going on in lichens that revised our understanding of when lichens first appeared on earth as well as what makes a lichen; at least certain lichens. I suspect they will always fool us; they are too complex to box into a category and leave them there.
The study originally looked for reasons some fungi and algae ‘hug’ each other and don’t let go. But along the way, the evidence seemed to show that fungi figured out how to do this in many places and times, not just from one ancestor. The earliest fungi to do this, that humans have evidence of so far, do not show up before ferns and a few other plants. So it may be that lichen did not colonize land before plants.
There may still be more surprises in the fossil records, and we may need to revise this story again in the future. It’s like a big puzzle; each piece is useful but only part of the picture. Even though we don’t have the whole puzzle figured out, we do see part of the story. Making adjustments, like sorting pieces-sky pieces we know go near the top of the puzzle, water pieces near the bottom- helps understand the patterns of life on earth even as we continue to search for the details.
For a life as simple looking as lichen are (to us), they do have amazing abilities to be flexible and adaptable; traits we might find useful. So the scientists continue to look for why and how the lichen do what they do, and I’ll let you know when I find out too!
(The title image is Chicken-of-the-Woods, growing behind my horse barn, on an old log.)
I have good friends in Canada who are film makers, and currently they are making a documentary on Chronic Wasting Disease. Of course, Wisconsin was one of their destinations for filming, as well as western states, England and Norway. If you eat meat, or simply care about the health of wildlife, it is probably a good idea to pay attention to new information on this and similar diseases, as information is updated. One of the team members who has been working on CWD in Canada for many years told me about some research on lichens and prion disease . The Tiny Ones continue to amaze with yet another complex and very particular activity they perform, unknown to us. It may be very useful to us to learn how they deal with prions. This research is a start.
The researchers found three lichens that affected prions. One of them was Parmelia sulcata, pictured above with friends Moss and Flavopunctilia sp. The other two lichens were Lobaria pulmonaria and Cladonia rangiferina. I don’t think that Cladonia grows in this part of Wisconsin, but Lobaria pulmonaria does; sorry I don’t have an image for this post. Check Sharnoff’s lichen pages for images. These three lichens have a serine protease activity that breaks down the prion. The only way humans know how to break down a prion is with the use of extreme heat, high Ph levels and the use of detergents. There may be many ways that lichens can affect prions; the scientists are just getting started looking at how lichens do what they do. It probably is the fungal, mycobiont that is affecting the prion changes, but the researchers have many questions yet about how the lichens do what they do. We have talked about the many complexities of the lichens’ interactions with the environment, and unanswered questions we have, in other posts, so this isn’t new to Kickapoo Lichen Lovers!
Humans have just started looking at what the lichens are doing, and there are thousands of lichens, so it would be reasonable to suspect other species may have similar abilities.
I love to think about why certain lichens would find it useful to de-activate prions. What interactions might occur in their part of the world, that causes a lichen to even notice a prion? Could a prion harm lichens? Does a prion interfere with photosynthesis, or other functions of the photobiont or mycobiont partners? Maybe the mycobiont is simply ‘hunting’….just to bag that rare prion. (It’s ok to laugh….)
We have known for a long time that lichens have many antibiotic properties; maybe half the lichen species humans have checked have some antibiotic function. Birds line nests with known antibiotic-making lichens, which may keep nestlings safer from disease. We know lichens can detoxify pollutants they extract from the air. Maybe one of their functions in the world is to clean things up.
We will never know all the reasons, or all that any plant or animal does with its life that is useful and necessary for the other plants, animals, microbes, insects, and everyone else in the Web of Life. Learning even a small part of what’s going on around us opens us up to wonder, and sparks interest and then, with any luck for all the other life on earth, we are motivated to take care, and do less harm. The news that my special friends the Lichens are already dealing with prions made me laugh. Of course! They have been here millions of years longer than us, and have had a long time to develop elegant responses to the world around them. May we be able to follow their example.
acrylic on panel
It’s been an icy and variable winter, making for hard to travel trails much of the time. After a warm spell I hiked with two friends to Black Hawk Rock in mid April on dry trails the whole way. This year in April, the lichens are still mostly dormant and their colors are muted. They very much want to cover the whole surface of the rocky ledge, but humans also very much want to perch on these rocks, and their heavy steps damage the lichens so there are numerous bare areas too. There’s room for all here, so please watch your step and avoid the areas where lichens are living.
The most obvious lichens are on the rocks, but take time to look at the cedar and oak trees. They support many lichens.
These are a few of the beautiful lichens living on the cedar trees at the summit. Lichens on the soil, rocks on the ground and at the base of the cliffs were all quite subdued compared to the last time I visited. Photographing the lichens on the rock summit and certain trees along the trail and comparing the images over time will allow us to learn about how lichens are changing in growth, species changes and generally how healthy they are. This is not a controlled experiment! I am casually observing on an irregular basis. Anyone who has observations to share about lichens please send your information to me, to add to the KVR information on our ecosystem.
A few days after visiting Black Hawk Rock, I walked part way up Little Canada trail, stepping around the muddy spots. There were many small branches on the ground from the recent stormy weather. Some had been on the ground for a while, so the lichens were beginning to die and the fungi, such as Turkey Tail, and also mosses were well established on the branches. After windy weather is an excellent time to search for evidence of lichens living in the canopy of the forest. It is almost impossible to see them unless they have the misfortune of falling to the ground. There may be lichens in the canopy that are not growing near the ground so it is valuable to check those fresh twigs we usually walk by without noticing.
The above photo shows an old branch from the canopy on Little Canada trail. It is a good example of the transition between a living tree and lichens and the fungi and moss that begin to grow as the tree dies. Gradually the tree becomes moss, fungi and then eventually forest soil that other trees will grow from, and the lichen will again appear on the new tree.
This is an branch of lichen in the canopy of the forest on Little Canada trail. The Parmotrema and Physcia lichen will live in lower areas of hardwood trees too. This branch has been on the ground for at least part of a year. The bark as well as the lichens are deteriorating but it is still possible to see the large size and complex structure covering the branch. The numerous small brown cups with blue gray foliose areas is the Physcia, the large, convoluted, leafy- looking greenish lichen is the Parmotrema.
Finding lichens from the canopy of the forest is an important part of learning about how healthy the forest is, and understanding the whole of the dynamic processes that are essential for sustainability. Considering only the species we are interested in for our own use, or because we think they are beautiful has led to many complicated problems in the Web of Life. The Tiny Ones, of all varieties (anyone small enough we have to slow down, look closely to see, or can’t see at all) are an essential part of sustainable life on Earth. As we learn to recognize them, and understand what they do, we will be able to make better decisions about how to interact with the rest of the world, and not least, will have endless new questions to ask and wonders to explore.
If you’d like to share a Liken’ Lichen Hike this spring or summer, contact me anytime. And please share this blog to help the KVR share our love of Lichens!
My friend Peter Schmidt was visiting Germany recently and found this tree branch in a woodland area. He thoughtfully shared it with your local Lichen Hunter. I have no idea what it is, but am going to spend some time with my lichen resources to challenge myself.
On the left there are some distant branches with yellow lichen; a careful look around this woodland might find more interesting species in addition to these bright yellow ones.
Here’s a closer view. Although the resolution is not good enlarged, we can see it is a foliose type of lichen; it has some leafy growth in areas and looks wrinkled, as if it is not tightly attached to the branch, as a crustose lichen would be.
Last summer I posted images from British Columbia, Canada, of the yellow lichens that are very common there in the fir and spruce forests.
The Letharia is a fruticose type lichen; it has branches, grows upright or trailing and is attached to the tree at small, discrete spots, just like a shrub growing in the ground.
Letharia vulpina uses vulpinic acid to make the yellow color, which is poisonous. In some parts of the north it has been used as a poison to kill wolves and other animals. It is toxic to any meat-eating mammal, as well as to molluscs and insects. But it does not affect mice and rabbits! The lichens use vulpinic acid to control the amount of light absorbed. (Lichen Biology, Thomas H. Nash III). The German lichen may use a different chemical to make its yellow color; a mystery I won’t solve today.
Remember, look for the Tiny Ones when you are out walking.