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.
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!