lichen ecology

Lichens and CWD

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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.

Parmelia sulcata + Flavopunctilia soredica wet 4.17 copy
Parmelia sulcata is the blue-green lichen with white edges

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….)

Usnea sp.-Canopy BV 3-17 Celestron
Usnea sp from canopy- microscope image

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.

Kickapoo Cathedrals 1
Lichen on river cliff

Spring Lichen Sightings

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BH Rock view 4.14.19b
Black Hawk Rock view to the south April 2019
R BH Rock-crustose 4.14.19
Black Hawk Rock-Umbilicaria americana, Xanthoria, various crustose lichens

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.

BHR-76 LT cedar Punctilia rudecta_ 11.17
Punctilia rudecta on cedar tree
BHR-74 LT cedar summit 4.17 Physcia and Xanthoria
Physcia sp. and Xanthoria sp. sharing a cedar branch

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.

DDT canopy Little Can Tr 4.14.19 moss fungi parmelia, ramelina, physcia
Old branch from the canopy on Little Canada trail

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.

LT canopy Little Canada Trail 4.14.19
Parmotrema sp. maybe! and Physcia sp.

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!

Susan