IF YOU HAVE QUESTIONS about lichens, you name a lichenologist. And so I did—in behalf of apprehensive readers asking what to do about lichens rising on the bark of timber of their backyard. The reply: Have fun! They’re manna from heaven (and actually that’s what manna from heaven was: two species of lichens).
That the presence of lichens is superb information comes on the authority of lichenologist Dr. James Lendemer, Assistant Curator in New York Botanical Backyard’s Institute of Systematic Botany. Lichens, one of many earliest types of land-dwelling life on earth, needs to be throughout you in a wholesome ecosystem: on bark, on mossy areas and different spots the place the soil could also be skinny, on wooden, and even defiantly on stones. They play key roles in maintaining an atmosphere in stability, too.
Learn my dialog with James as you hearken to the June 8, 2015 version of my public-radio present and podcast utilizing the participant under. You possibly can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts right here).
Learn extra on the backside of the web page concerning the new lichen area information, “Frequent Lichens of Northeastern North America,” revealed by the New York Botanical Backyard Press.
learn/pay attention: my lichen q&a
with dr. james lendemer
Q. Sadly the commonest lichen query I get requested as a backyard author is, “How do I kill the lichen on my timber?” And naturally the reply is, “Don’t!”
A. No matter you do, don’t. [Laughter.]
Q. So earlier than we get to extra on that, James, what are lichens? Perhaps it’s simpler to say what they’re not—like, they aren’t vegetation, are they?
A. They aren’t vegetation, they usually’re additionally not animals. Traditionally, lichens have been truly thought-about to be vegetation; they have been initially categorised with them. That’s why you’re calling a botanical backyard to speak to a lichenologist—whereas most individuals that research fungi are at establishments that research plant pathology or issues like that.
These organisms have been historically handled with vegetation, however in reality they’re truly fungi which have advanced a novel way of life that entails capturing an alga for the needs of acquiring vitamin.
Q. So “capturing an alga”—like algae?
A.Sure; some folks name them “fungi which have found farming.”
Q. “Fungi which have found farming.” In order that’s what they’re—they’re very intelligent creatures, aren’t they?
A. That way of life has actually helped them to adapt and survive in a few of earth’s harshest habitats—to actually be capable of take over and change into numerous and ample just about all over the place on land, all around the world.
So lichens are literally fungi, they usually’re fungi that get along with this alga and kind a physique that appears utterly not like the 2 completely different components, the 2 completely different organisms. What you see within the wild is that this composite organism fashioned by the 2. It’s dominated by the fungus, however the algae are in there, too.
Q. They’ve their very own entire language. Is what you simply described a cryptogam?
A. Consider cryptogams as form of the lesser vegetation—so it contains the ferns, for example. Historically in botany, cryptogams embrace all the forgotten or lesser-studied or smaller organisms; issues that don’t have flowers for probably the most half. So that you’re pondering of ferns, of the bryophytes (mosses and liverworts) after which lichens and fungi and algae as effectively.
Q. How outdated are lichens; when did they first come on the planet?
A. It’s very fascinating: Lichens are considered one of many earliest types of land-dwelling life, which is simple to think about when you have a fungus floating round in very historic oceans, and you then even have algae on the market. Getting collectively and forming this composite organism is a method for the fungus to get onto land, and likewise a method for the alga to get onto land.
The alga will get safety from the fungus—it’s dwelling contained in the fungus—and the fungus is getting vitamin from the alga, in what’s probably an space the place there wouldn’t have been a vitamin supply to begin out with.
Q. So it’s a profitable partnership.
A. Oh, for certain.
Q. Do they happen worldwide, and in a variety of habitats? What can we are saying about the place they’re and what they want?
A. Lichens needs to be throughout you—on timber, on rocks. As you so eloquently put at first of the present, they need to be on timber, on rocks, on outdated logs, on soil—actually something that they will develop on they’ll develop on.
Q. Any substrate?
A. Sure, and in Antarctica—within the harshest circumstances the place there’s a rock uncovered in Antarctica, there will probably be a lichen. Within the harshest deserts of the arid West, and in Africa, there are lichens there. They survive and thrive in lots of locations the place vegetation and animals can’t.
Q. There are a lot of colours of lichens—why? We stated they’re composite organisms, however why are some extra orangey and a few grey, some greenish, yellow…how does that occur?
A. What causes that outstanding variation in coloration that you just see in nature? The colour that you just see is definitely substances which might be secreted—chemical compounds which might be secreted by the fungus. They form of combination across the fungal hyphae, across the particular person fungal strands that kind a fungus. They really are secreted after which form of crystallize round them.
These pigments you’re seeing are sometimes within the higher floor or the outer layers of the lichens. These are literally functioning in some ways, and one of many main ones is considered as a protectant from UV radiation—it’s defending the fungus and alga contained in the precise lichen.
Q. Wonderful.
A. They’re not simply doing it for us, for our pleasure, however we will admire them nonetheless. All these completely different colours—the reds, the oranges, the yellows, the greens—these are all completely different substances produced by completely different species of lichen.
It needs to be stated that lichens are outstanding as a result of they produce lots of or 1000’s of chemical compounds not discovered wherever else in nature, and a few of them are recognized to have biomedical or bioactive properties.
Q. Have they been utilized in medication, and in different methods ethno-botanically?
A. Sure, for 1000’s of years. I prefer to say that lichens, and extra typically talking fungi, are cultural touchstones for people to form of perceive the really numerous cryptogam variety that exists in nature.
There’s this large variety—thousands and thousands of species—that most individuals don’t admire, truly happen throughout them. Lichens and fungi on the whole are the one touchstone folks have, as a result of they’ve these deep, long-running cultural connections.
Many native peoples’ perception methods truly contain fungi and lichens. The Biblical manna from heaven—that was a lichen.
Q. I didn’t know that.
A. We even know what species they have been—two species of crustose lichens that develop within the deserts of the Center East. Within the mornings, when the whole lot form of dews up just a little bit, they puff up and they also seem to come back out of nowhere. That’s what was eaten within the desert at the moment. Isn’t that outstanding?
Q. You simply used the phrase crustose. We talked concerning the variety of coloration in lichens, however there are additionally textural groupings, and crustose is one, sure?
A. Sure. When you’ve got your Biology 101, what most individuals study lichens is that they arrive in kind of three completely different progress varieties. And people varieties consult with the thallus, or physique, that the lichen is forming—that composite organism of the fungus and alga.
The primary kind is fruticose—bushy and branching and really three-dimensional. They stand out from the substrate, like little timber. When you’ve got a mannequin practice set and have the pretend timber they use in mannequin practice units, these are sometimes made from fruticose lichens which have been dyed.
Q. Manna from heaven, toy practice timber…
A. The place aren’t they? [Laughter.]
The second sort are the foliose lichens, and people are the lichens which might be leaf-life, with an higher floor and a decrease floor. They aren’t truly connected to the substrate that they develop on, however moderately they’re connected by secondary construction which might be just like roots, however they don’t truly uptake vitamins. They’re simply attachment organs.
Essentially the most numerous sort (and the least studied) are the crustose lichens, that are principally only a paint, extra of much less. Some folks consider them as stains, however I favor not to consider them that method.
Q. That’s a destructive phrase.
A. We prefer to pattern optimistic. However you possibly can consider them as work on timber, rocks, what have you ever. They’ve an higher floor, however they don’t have any distinct decrease floor that separates them from the substrate. They don’t have these attachment organs; they’re simply rising instantly on the substrate.
Q. The way in which I realized about lichens–as many issues occur for me, I used to be out within the backyard, and had my digicam, and there was this unusual-to-me-insect on the aspect of the barn. I took a photograph [above], after which additionally took a photograph of some lichens on stone throughout the yard [below]. Once I went inside to key out the insect, I came upon it was a painted lichen moth. That’s not an insect that has an curiosity within the lichens on the stone on my patio…however this led me to the “aha” that lichens do greater than sit there and look intricate and delightful. [Laughter.]
There’s this entire interplay: somebody would possibly eat them or reside in them. Flying squirrels use them for his or her nests?
A. And hummingbirds.
Q. They acquire lichen as effectively? Fascinating. So what different examples are there of what they’re doing right here, and the way they slot in?
A. I like to consider it—and it might be my bias as a lichenologist [Laughter]—when you have a forest, or an ecosystem you possibly can consider lichens as being hubs inside that ecosystem.
There are a lot of completely different processes which might be occurring—it’s a really dynamic system. In the event you’ve been in a forest or been in a backyard, that nature may be very dynamic naturally. A whole lot of that dynamism occurs round, and thru, lichens. So lichens are concerned in all kinds of issues. In the event you consider what they’re consuming, and what’s consuming them: They’re essential in breaking down rocks, in order that they kind soil. When you’ve got lichens, you’re in a position to kind soil, and you’ll have mosses and vegetation develop. In the event you didn’t have lichens doing that, there can be so much slower erosion of rocks, and so much slower formation of soil.
They’re additionally necessary in nutrient biking—like in Nitrogen-fixing.
And if you happen to’re pondering of it as what’s consuming them, it ranges from animals as giant as caribou, which rely nearly completely on lichens for his or her winter weight loss plan—with out lichens they wouldn’t survive. And animals as small as flying squirrels or hummingbirds making nests, after which it will get even smaller.
There are lots of if not 1000’s of distinctive interactions between bugs and different invertebrates and small animals—like your lichen moth [above, yellow and black lichen moth at Margaret’s garden]—that both eat the lichen, or use the lichen as camouflage to guard themselves.
In the event you go at an excellent smaller, finer scale: Throughout the lichen itself, inside that physique composed of the fungus and the alga, there’s a entire tiny world or universe that features many types of life that happen nowhere else exterior of it.
There are micro-invertebrates, like Tardigrades or water bears—if you happen to’re not acquainted with what a water bear is, I strongly urge you to Google that. There are stunning coloration scanning electron micrographs on the web of them. Fabulous little creatures—they usually reside within the intercellular house of the lichens. And there are distinctive fungi and micro organism that reside inside the lichen themselves, that don’t happen exterior of them. A lichen is a really complicated, dynamic factor.
Q. I used to be sitting in a restaurant just lately within the Berkshires of Massachusetts, a spot I am going frequently, looking to a woodland edge alongside a wetland. I seen one thing I hadn’t earlier than: Each tree amongst many, many very outdated timber there have been lined with lichen. So stunning. However then I drove dwelling not distant, and on my street, there may be not a lot of that.
I do know it’s a query you possibly can’t reply with out being there, however typically talking, why would one place be so extraordinary by way of lichens?
A. It shouldn’t be. In the event you take a look at lichens traditionally—and we all know this due to the sources at museums and establishments just like the New York Botanical Backyard, the place we’ve had scientists gathering lichens, vegetation, all form of issues for hundreds of years—we all know based mostly on historic specimens that many species of lichens have been extra widespread and widespread than they’re right this moment.
Actually it’s the identical story that you just hear with many different elements of biodiversity—the lack of wildflowers from many areas, the decline of wildflowers, the decline of migratory birds. The extinction disaster that we’re in proper now; the biodiversity disaster that’s looming.
That’s one thing that lichens have been experiencing for a while, however they’re one of the visible symbols or ways in which folks can join with what’s taking place within the atmosphere, as a result of lichens are form of like a canary in a coal mine.
Q. I used to be pondering that: They’re like a bellwether, or a canary in a coal mine.
A. They’re glorious indicators of air air pollution particularly, or habitat high quality on the whole. When an ecosystem or the atmosphere on the whole is degraded in any variety of alternative ways, the lichens are sometimes one of many first and most visibly impacted teams of organisms.
In order that’s what you’re seeing: Both there are legacy results, or ongoing results, from the change that we’re wreaking on the pure world. In the event you go to mature old-growth forests that exist in main cities—for example, Fairmount Park in Philadelphia or the Thain Household Forest right here on the New York Botanical Backyard—we have now outdated forests with mature timber, however they’re nearly devoid of timber. The explanation for that’s the air air pollution and the general habitat degradation that persevered for over a century.
The Clear Air Act considerably improved air high quality, and because of this lichens have begun to recolonize in lots of areas the place they have been extirpated prior to now. However that being stated, it’s a really sluggish course of that takes centuries if not longer.
What we’re seeing is de facto the legacy of the Industrial Age, you possibly can name it. We truly right here on the Botanical Backyard have begun to reintroduce species we all know grew right here 150 years in the past. We tried to reintroduce them right here with the thought that our air and our water has gotten so much cleaner. We have an interest to see whether or not or not with just a little little bit of a serving to hand we will deliver species that happen possibly 100 miles away, and would have occurred right here traditionally, to develop right here once more.
The issue is just not a lot the standard of the atmosphere now in some locations a lot as how species have been pushed away from such huge areas, that they will now not recolonize. A lichen can solely transfer so rapidly.
Q. I need to point out as I did at first: So many individuals see lichens on a tree and suppose it’s a parasite, or a illness. However it’s not an indicator of some downside.
A. It’s an indicator of excellent. [Laughter.]
Q. I wished to have you ever say that, as a result of you’re the lichenologist.
A. Lichens don’t hurt the substrates that they’re rising on. They don’t have roots that penetrate into the substrates; they’re not acquiring vitamins from timber or shrubs they’re rising on. They get all their vitamins from the algae, and from the air particulate matter and the water vapor within the air—which is why they’re so delicate to air air pollution and different types of environmental degradation.
So don’t lower them off your timber.
Q. Have fun them.
A. Sure.
Q. And in anticipation of our dialog, I went out once more this morning with my digicam, and I assumed: I’m simply going to stroll round my place, which is 2 acres, and I’m going to take an image of each lichen I can discover. It was so fascinating—there have been so many I had by no means seen.
Do you advocate doing that with a hand lens? This new area information from New York Botanical Backyard Press is nice. [James using a hand lens, above, and a detailed photo from the new book.]
A. It’s a novel useful resource; there may be nothing prefer it that has been revealed earlier than.
Q. For actual folks.
A. Sure, not only for scientists, for actual folks. It has stunning coloration pictures. You could possibly open that e-book to a web page, and if you happen to had a hand lens and also you have been taking a look at a lichen, you possibly can with a excessive diploma of chance determine the lichen, if you happen to have been within the Northeast. Traditionally most of the area guides has fuzzy photos, in black and white, and didn’t do the lichens justice. It made it exhausting for folks to determine them. This e-book makes them way more accessible. It’s a method so that you can admire a element of the natural world of your yard that lots of people may not have been conscious of or appreciated earlier than.
Q. And so they’re necessary organisms—not simply stunning. They’re attempting to inform us one thing about what’s occurring round us.
A. They’re just like the canary in a coal mine, they usually’ve been singing for over a century. Sadly no person has heeded their music.
favor the podcast model of the present?
MY WEEKLY public-radio present, rated a “top-5 backyard podcast” by “The Guardian” newspaper within the UK, started its seventh yr in March 2016. In 2016, the present received three silver medals for excellence from the Backyard Writers Affiliation. It’s produced at Robin Hood Radio, the smallest NPR station within the nation. Hear regionally within the Hudson Valley (NY)-Berkshires (MA)-Litchfield Hills (CT) Mondays at 8:30 AM Jap, rerun at 8:30 Saturdays. Or play the June 8, 2015 present utilizing the participant close to the highest of this transcript. You possibly can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts right here).
enter to win the lichen area information
I’VE BOUGHT an additional copies of “Frequent Lichens of Northeastern North America,” revealed by the New York Botanical Backyard Press, to share with a fortunate reader. All it’s a must to do is reply this query within the feedback field on the very backside of the web page (after the final reader remark):
After studying this story or listening to the podcast, what stunned you most about lichens? What didn’t ?Foolish me: I had no thought about their position in soil-building, by serving to rocks break down extra rapidly than would in any other case occur. (I didn’t know concerning the manna from heaven-lichen connection, both.) I’ve lengthy beloved them, and knew they have been excellent news, however not within the element James Lendemer shared.
Feeling shy, or don’t have any reply? Simply say, “Rely me in” or one thing to that impact, and I’ll, however a solution is best. I’ll decide a winner U.S. or Canada) after entries shut at midnight Sunday, June 14. Good luck to all
(All pictures besides lichen moth and lichen on Margaret’s patio from James Lendemer, used with permission. Disclosure: Purchases from Amazon hyperlinks might yield a small fee.)