Lichen in the Garden

Lichen in the Garden By Dianne Machesney, Master Gardener , Allegheny County, PennState Extension

Crustose lichen on stone. Photo credit: Dianne Machesney

What's that growing on my tree trunk? Is it harming my tree? Don't panic. Chances are it is a lichen.

Since 1867, scientists have recognized that lichens are symbiotically associated with fungi and protists (bluegreen alga.) The fungus provides a physical structure and offers its partner protection from the environment. The algae, which is slimy and has no structure, provides the food through photosynthesis. It converts energy from the sun and carbon dioxide into sugars. The carbohydrates in this food help produce new growth, called the thallus, which looks different than the two hosts.

In 2016, scientists at Purdue University uncovered a third partner, yeast. The yeast enables the lichen to produce acid that helps defend it against invasion from other microbes.

Lichens are located on every continent on earth, in every climate and altitude. They only require an undisturbed surface, time, and clean air. Lichens are very sensitive to air pollution. They are rarely found in urban areas. Finding lichen in your garden means that your environment is clean enough to support them. A good thing!

Lichens grow on any undisturbed surface--bark, wood, mosses, rock, soil, peat, glass, metal, plastic, and even cloth. Lichens have their favorite places to grow. For instance, a lichen that grows on bark will rarely be found on stone. Lichens can absorb water through any part of their thalli and have no need of roots.

Lichens do not damage plants or rob the bark of moisture. They do not parasitize living plant cells, and studies show that there is no association with pathogens entering plant tissue and causing disease.

With more than 3,600 species in North America, lichens are beautiful, diverse, and ecologically important. They help the environment by reestablishing life on rock and undisturbed sites. As lichens colonize, they trap dust, which plays a role in soil formation. Lichens contribute to the nitrogen cycle by converting the nitrogen in the air into nitrates that help in their growth and development. Their ability to fix atmospheric nitrogen is beneficial to other plant life as well. Rain leaches nitrogen from both living and dead lichens and makes it available to plants in the immediate area. When lichens die, they contribute to decayed organic matter, which enables mosses and seeds to begin developing among the pockets of new soil.

Lichens are not especially tasty and few of them are poisonous. They have been used as food in numerous cultures, as medicine and as a dye. Animals use lichens for food, and shelter too. They are the basic sustenance of caribou. Around 50 species of birds regularly use fruticose lichens as their preferred nesting material.

Lichens are diverse. They can be green smudges on a rock, orange, yellow, or white patches the size of your palm, or draping gossamer. They are not a moss. The misnamed reindeer moss is actually a lichen.

There are three main body types—foliose, fruticose, and crustose. Foliose lichens produce leaf-like flattened, lobed thallus. They are commonly found growing on tree trunks. Fruticose lichens grow erect and have visible fruiting bodies. Crustose lichens form a crust over their host; some of these are brightly colored.

Lichens do no damage to tress and should not be removed. But they should be removed from garden statues or sculptures because they can penetrate and damage the stone. Scraping does not remove the entire thallus, so use sprays containing copper salts to control lichen growth.

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overboard to include those who may behave in a way that will cause you to regret the invitation. It is possible to extend kindness to someone with whom you disagree, especially if the situation is for the good of the children. When making your decisions, take into consideration any negative aspects, and base your choice on whether the children will benefit from the visit, social gathering, or other activity. Weigh the positives and negatives and do what is best for them.

The COVID-19 Pandemic Is Affecting Your Memory

Research demonstrates our memories are not as accurate as we believe.

While most people think their memories represent the truth, the evidence demonstrates that our memories depend very much on the circumstances we are experiencing at the time and that they shift over time. A large body of research shows that emotions, especially those provoked by negative events, lead to inaccurate or even completely false memories.

Depression, anxiety and stress – three mental health problems linked to the COVID-19 pandemic –consistently lead to false memories, said Charles Brainerd, a Cornell University psychologist and one of the world’s leading experts in false memories. “Continuously being in a dark mood makes it difficult to remember the details of your life,” he said. “Things that substantially elevate people’s stress levels lead to poor encoding of events as we experience them, which in turn elevates false memories.”

Brainerd and his research partner, Cornell psychologist Valerie Reyna, have developed the fuzzy-trace theory of false memory, which says that there are two types of memory: verbatim and gist.

Verbatim memory is a vivid, literal record of specific details. Gist memories are fuzzy recollections of past events, which capture their meaning and have a much more powerful influence over longer periods of time. In other words, if you are remembering an event from a year ago, you are more likely to rely on the gist of what happened than remember specific details. False memories occur when your brain attempts to fill in the blanks of a gist memory.

Warren County Connection sistent negative moods are at elevated risk of forming false memories because the memories are distorted to fit a negative take on life,” Brainerd said. “Prolonged levels of high stress from continuing financial, educational and social uncertainty are a major cause of persistent negative moods. Thanks to the uncertainties of the COVID19 pandemic, the entire country has been experiencing such prolonged levels of high stress for many months. Worse, those uncertainties have been heightened by the lack of clear federal policies to contain the pandemic.”

There is another dynamic taking place this year that may also lead to false memories – the increasing incidence of misleading or false news stories.

A recent study by Irish researchers, which included more than 3,700 participants, examined how fabricated news stories about COVID-19 affected the accuracy of participants’ memories about the virus itself. People who were able to objectively assess knowledge about COVID-19 were less likely to create false memories and more likely to tell the difference between true and false stories.

On the other hand, participants who believed themselves to be very knowledgeable about COVID-19 were more likely to report a memory for any story, true or false. Those who reported high levels of “media engagement” or anxiety about COVID-19 were more likely to recall both true and false stories, but also demonstrated heightened sensitivity to the difference between true and false stories. Surprisingly, participants who felt more anxious about the pandemic were less likely to report false memories.

The researchers concluded that a person’s knowledge about COVID-19 and his or her tendency to think critically are important indicators as to whether or not they create false memories related to the pandemic.

The take-home message: Our memories are malleable and our circumstances have a surprisingly important effect on them. The experiences of the COVID-19 pandemic – including social distancing, isolation and anxiety about the virus – are all elements affecting our memories during this time.

Visit Cornell University’s Bronfenbrenner Center for Translational Research’s website for more information on our work.

By Tom Ellis, Michigan State University Extension, Department of Entomology

It's time for the fall inspection of the old homestead. Winter weather will only exasperate the problems you have now. Any repairs you do will also reduce the numbers of insects and other critters that "magically" appear during sunny winter days and early spring.

Many insects and similar creatures seek out houses to spend the winter. Put yourself in the bugs place. Would you rather spend the winter under a rock or bark flap of a tree, or would you rather curl up and take a five-month snooze in an attic or wall void? This is natural selection in action. Your household offers them a better deal.

Let's use my house as an example. We'll take a walk around, in, and on top of it and inspect the structure for possible minor maintenance needs. Every repair that I make will dissuade one or several species of insects from becoming a member of my household. Also, any repairs that I make will totally astound my spouse and friends!

Keep in mind that no house in this day and age will ever be 100 percent insect proof. In fact, insect proofing, other than a termite barrier, is never a consideration when a house is designed or constructed. Probably the last (and maybe only) insect proofing innovation in new home construction was the invention of wire window screen!

My house is a basic ranch style with 1,300 sq. ft. It was built in 1957. It has three bedrooms: one for my wife and I and two for our cats. It has a basement, attached garage and scuttle-access attic. The basement is finished. There is a fireplace in the basement and living room. The siding is vinyl over wood (probably cedar). The insulation under the siding is Styrofoam. The insulation in the wall and ceiling is fiberglass batting. The house had new asphalt roofing put on in 1986. The house has an attached deck in back running approximately two-thirds the length of the house. The back of the garage has cabinets built in for storage of screens, storm windows and miscellaneous junk.

So, grab, or borrow, an extension ladder and let's take a look at the gutters, roof, chimney and vent pipes.

Gutters

Gutters should be cleaned out every fall after most of the leaves have fallen. At least three or four species of mosquitoes will lay eggs in and on gutters. In addition to the mosquitoes, we can find several other species of aquatic fly species in my eave troughs.

Some are biting species, and some are not. While we're here we'll check fascia and soffits. Wasps, carpenter ants and even carpenter bees will be attracted to fascia and soffits that are not in good repair.

Roof

Up on the roof, we'll check for loose shingles and rotted boards. These areas are especially attractive to carpenter ants and a variety of insects that overwinter as adults. Prune back branches of trees and tall shrubs that hang over or touch the roof.

Carpenter ants actively scavenge for food on these plants and will move on to the roof if we provide a "branch bridge."

Chimney

While we are up here, we'll check flashing around the base of the chimney and consider whether it should be tarred soon. Check for loose bricks in the chimney. Both areas are great spots for various wasp species to overwinter. Make sure there is a screen covering the chimney opening. This will discourage squirrels, birds and raccoons. If you have a fire place, you don't want to be roasting a dead raccoon with your first romantic fire of the fall season!

Vent pipes

One more stop and we can go back to terra firma. Let's check to see if the vent pipes are clear of debris. Check the flashing around the vent pipes too.

Siding, windows and doors

Back on the ground we can now inspect siding, windows and doors for cracks, holes, and weather stripping that

needs replacing. Check boards for rot. Probe boards, especially around door and window casings, with a pen, knife or an ice pick. Rotting boards will puncture easily. If they are rotten, check for termite and carpenter ant damage. If you discover termite damage, fall is a good time to find it. You really don't need to take corrective action until spring. This will give you ample time to select a pest control company and make the most favorable deal (economically) for you. Be wary of companies that will try to pressure you into taking quick action and those that do not find termites, but offer to sell you a "protection" contract.

If you find an area that you suspect was an active wasp or hornet nest, note where the exit/entrance hole is and wait until March to caulk the hole. This will ensure that it has been vacated for the year. Do not plug the entrance if you think there is any chance of activity this fall. Wasps and hornets can chew there way out on the other side and into your living area.

Insects commonly found making their way into wall voids and other suitable areas by way of cracks and crevices in the siding and through improperly sealed doors and windows include: cluster and house flies, wasp and hornet queens (and an occasional worker that has not yet died), honey bees, box elder and leaf-footed pine seed bugs, elm leaf beetles, various ants, mosquitoes that overwinter as adults, crane flies, and spiders.

Basement foundation and windows

As we look at the foundation and basement windows, we will be checking for cracks, holes, cracked and loose mortar, and weather stripping that needs replacing. The same critters that attempt to enter through siding, windows and doors will also try to make their way into your basement. Basements are favored habitat for pill and sow bugs also. While you are at it, get rid of cardboard boxes and other items that hold moisture and attract these beasts. Check the outside foundation for gypsy moth egg masses. They should be removed and destroyed.

If you store birdseed or dry pet food in the basement, keep it in a sealed metal container. This is a good place to get a whole raft of pantry pests started.

If you have a crawl space, be sure that there is plenty of air circulation through it. This will discourage rotting and the buildup of various fungi and molds.

Attic

Check the attic vents. This can be done by going into your attic or with the extension ladder. From the outside, the screens should be in good repair. If they have holes, check the attic for bird and rodent nests. They will probably contain bird mites, bat bugs, and carpet beetles that will eventually find their way into the house after they've run out of feathers and other goodies to feed on. Also, remove nests from house eaves, gutters, etc. for the same reason.

Attached garage and out buildings

We can't quit yet. The procedure here is the same drill as the house proper.

Over the course of the next month or so, insects like boxelder bugs, lady bugs and cluster flies will accumulate on house siding and on the outside surface of windows, sometimes in large numbers before finding their way under siding and into wall voids. This will be especially conspicuous on the south side of buildings. Routine removal and disposal of these insects is an appropriate pest management action.

"Giving Thanks" by Author Unknown

For the hay and the corn and the wheat that is reaped, For the labor well done, and the barns that are heaped, For the sun and the dew and the sweet honeycomb, For the rose and the song and the harvest brought home Thanksgiving! Thanksgiving!

For the trade and the skill and the wealth in our land, For the cunning and strength of the workingman's hand, For the good that our artists and poets have taught, For the friendship that hope and affection have brought Thanksgiving! Thanksgiving!

For the homes that with purest affection are blest, For the season of plenty and well-deserved rest, For our country extending from sea unto sea; The land that is known as the "Land of the Free" Thanksgiving! Thanksgiving!