Tuesday, March 14, 2017

Moody Microbes

How are you feeling right now? Happy or sad? Angry or content? The microbes living inside of you, particularly those in your large intestine, are partially responsible for your state of mind right now.

Bacteria from the genus Lactobacillus, a genus of bacteria often found in the intestine.
A creative commons image. Source.  
Microbes—tiny creatures that aren’t even part of the human body—influence the brain?

Yes, intestinal bacteria, and the food we feed them, play critical roles in how we feel. 

Diagram of the large intestine, where our gut bacteria live,
 A creative commons image. Source: Blausen.com staff (2014). "Medical gallery of Blausen Medical 2014". WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436
Here’s how bacteria and diet influence the brain:

Microbes talk to the brain through the immune system. Dendritic cells—immune system cells in gut lining—constantly monitor microbes for misbehavior. If the dendritic cells sense that the intestinal bacteria are acting up, they trigger the release of cytokines—compounds that cause gut inflammation.

Cytokines communicate with the brain in two ways: as hormones and as signals sent via the vagus nerve—a thick nerve connecting the gut to the brain. These hormonal and nervous system signals make the brain reduce energy levels, and increase pain sensitivity. Cytokines can even induce feelings of sadness often felt during a stomach ache or gut infection.

It doesn’t require a full-blown gut infection to induce gut inflammation—simply eating a diet high in animal fat can cause the release of cytokines—and the subsequent mood drop.
Bacteria from the genus Klebsiella, a genus often found living in the gut.
A creative commons image. Source.

Microbes also signal the brain through metabolites—byproducts of microbial digestion. The metabolites microbes produce change based on what food we feed them. Metabolites travel through the bloodstream and act as hormones in the brain to influence our moods.

Bacteria from the genus Lactobacillus, a genus of bacteria often found in the intestine.
A creative commons image. Source.
 Generally, food that is good for humans also is good for our bacteria and causes them to release beneficial metabolites. Some metabolites, like those released after eating whole grains and vegetables, trigger release of serotonin, a neurotransmitter which is linked to improved mood. Fatty, unhealthy food on the other hand is likely to cause gut inflammation and the depressed mood that comes with that condition.
Illustration of a human brain. A public domain image. Source.

Gut microbes are so vital to our emotional state and thought process that scientists are starting to think of the gut, the brain, and the human microbiome as a connected system rather than separate entities. This system is often called the gut/brain/microbiome axis. Next time you are in a good mood remember to thank your intestinal microbes!

Check out a previous post I wrote on microbes, We Need Bacteria, to read about the connection between microbes and food allergies.

Friday, February 17, 2017

It's Alive! The Sourdough Experiment Part Two

Here’s a jar of flour and water, also known as my sourdough starter. It’s pale, bubbly, and sour-smelling. 
Photo by blog author.
My sourdough starter, like every sourdough starter, contains a unique combination of yeasts—which make sourdough bread rise—and lactic acid bacteria—which make sourdough bread sour. The external environment, the temperature, and the type of flour used influence which specific types of yeast and lactic acid bacteria are present in a sourdough starter. Each sourdough microbiome produces a distinctively flavored sourdough bread. The bread made with my starter tastes different than the bread made with any other starter, but the process for making all sourdough starters is basically the same.

Inside of a sourdough starter both yeasts and lactic acid bacteria break down carbohydrates in the flour for fuel. (To learn more about this process see my last post.)

Do yeasts and lactic acid bacteria compete with each other for resources in the starter or do they work together?

Well, they do a little bit of both.

Yeast and lactic acid bacteria do compete with each other for resources like carbohydrates, and nitrogen, used to make proteins.  But, despite occasional skirmishes, yeast and lactic acid bacteria work together to successfully survive in the sourdough starter.

We know that yeast and lactic acid bacteria both break down carbohydrates in flour. What I did not mention yet is that there are different types for carbohydrates in flour, like maltose, glucose, fructose, and sucrose. Yeast can digest some of these carbohydrates and lactic acid bacteria can digest others. Yeast and lactic acid bacteria collaborate to consume all these carbohydrates. Here’s an example of how the common sourdough yeast species Saccharomyces exigus and lactic acid bacteria cooperate.
 
Image by blog author
While the yeasts are digesting carbohydrates, they also release amino acids lactic acid bacteria need to survive.

But what do all these microbial interactions mean for us, the ones eating the sourdough?
While breaking down carbohydrates for their own fuel, yeasts and lactic acid bacteria make these carbohydrates easier for us to digest. Because of this, eating sourdough bread does not cause abrupt spikes and drops in blood sugar levels like eating bread made with packaged yeast does.

Sourdough yeasts also help us absorb minerals more easily. Here’s how:
Image by blog author.

In addition to being healthy, well-made sourdough tastes great! Yeasts and lactic acid bacteria in the sourdough starter produce lots of tasty compounds, like buttery diacetyls, and sour organic acids. Just think—most of the flavor and microbial complexities in sourdough bread originated in a jar of flour and water.


Thursday, January 26, 2017

It's Alive! The Sourdough Experiment Part One

 The first loaf of sourdough bread I made tasted good covered in melted cheese—in the way I imagine cardboard would taste good covered in melted cheese. My sourdough bread was dry, crumbly, flavorless, and barely edible.

The dry, crumbly bread. Photo by blog author.

What went wrong? I have a few ideas, but before I share my hypothesis for the Great Bread Failure, let me explain what exactly sourdough bread is.

Bread is leavened with yeast—a microscopic fungus which breaks down carbohydrates in flour and releases carbon dioxide and ethanol as byproducts. The carbon dioxide released by the yeast fills the bread dough with gas and makes the dough rise, giving the bread the fluffy texture we expect.

Dry packaged baker's yeast. Photo by blog author.
Most bread we make and eat today is leavened with dried baker’s yeast—Saccharomyces cerevisiae—a yeast species specifically bred for its leavening capability. S. cerevisiae isn’t the only yeast that can leaven bread. Wild yeasts growing on food and on practically every other surface can also be used to make bread—if we can catch them.

A sourdough starter, simply made of flour and water, is the way people harnessed the power of wild yeasts for centuries. This starter is used in place of dry yeast to make bread. Or, I should say dry yeast is used in place of a sourdough starter, as dry yeast is a fairly recent invention and originally all breads were sourdough.

My bubbling sourdough starter. The bubbles are carbon dioxide being released by the yeast.
Photo by blog author.

The water in the sourdough starter prompts flour enzymes to break down starches in the flour into carbohydrates that yeasts can digest. The yeast naturally found in the flour begin to ferment these carbohydrates and release carbon dioxide, ethanol, and a variety of other byproducts, including B vitamins and organic acids.

The yeasts in the sourdough starter are joined by lactic acid bacteria, a type of beneficial bacteria which lives on food and in soil. The lactic acid bacteria also ferment carbohydrates in the flour, but the main byproducts they produce are lactic and acetic acid. Lactic acid bacteria are responsible for the “sour” in sourdough. (To learn more about lactic acid bacteria check out my blog post on vegetable fermentation.) 

Once a sourdough ferments for about a week, it is ready to be used to make delicious sour bread.

Or in my case, not-so-delicious bread. My sourdough didn’t even taste sour!

The sourdough recipe I used called for baking soda, another leavening agent mainly used in quick breads. Baking soda reacts with acid to release the carbon dioxide which allows the bread to rise, but during the reaction the acid is neutralized. When I mixed baking soda with my sourdough starter, it fizzed like a baking-soda-and-vinegar volcano releasing copious amounts of carbon dioxide. While the baking soda helped my bread rise faster, it also neutralized all the tasty lactic and acetic acid in the dough, leaving my concoction decidedly un-sour and un-tasty.

Baking Soda. Photo by blog author.
Sourdough starters contain yeast, and baking soda is not needed to leaven the bread. However, sourdough breads take a very long time to rise, which is why some recipes call for baking soda to speed along the rising process. But baking soda destroys the sourdough’s flavor, and I don’t think the faster leavening time is worth it.

The baking soda explains why my bread wasn’t sour, but not why it was so dry and crumbly.

When I was making my sourdough, I got a little carried away with adding whole-wheat flour. Whole-wheat flour is very healthy, but the bran in it soaks up lots of water—more water than I accounted for. Since I didn’t add enough water to the dough I ended up with dehydrated and unappetizing bread.

Despite my struggle with my first sourdough attempt, I was determined to try again, and sourdough take two turned out wonderfully! I did not use baking soda and I used a mixture of both whole-wheat and white flour to avoid the dehydration problem.

The tasty sourdough bread! Photo by blog author.

Why was I so determined to repeat the sourdough experiment? One reason is because well-done sourdough is delicious and has many health benefits, but the reason I really am interested in sourdough is the dynamic and little-known relationship between the yeast and lactic acid bacteria in the sourdough starter. More on that relationship in my next post!


Friday, December 9, 2016

Lichens: A Burst of Color on a Dark Day

The lichens have awoken.
Lichens, moss, and mushrooms in the Palisades.
Photo by PBM. Used with permission.

 Late autumn, almost winter. The trees are bare and the sky is grey. A light mist falls. New York City seems devoid of life. Scaffolding drips and trains run late.

Grey day on the Hudson River.
Photo by PBM. Used with permission.

Across the Hudson River, a few miles away from the dead-grey of the city in the Palisades Interstate Park in New Jersey delicate greens and specks of mustard yellow coat rocks and trees in a quietly vibrant layer.

Lichens on a rock in the Palisades.
Photo by PBM. Used with Permission.

On a cheerful sunny day, the same lichen appear as a crusty dust on a rock, but in the dismal rain these creatures burst forth.

My rainy hike in the Palisades reminded me of my love for lichen and then I realized something rather embarrassing: I knew relatively nothing about my favorite organisms. The lichens I saw inspired me to learn more about them.
Lichens on a tree in the Palisades.
Photo by PBM. Used with permission.

Lichens are intricate beings, and before we can delve into their complexities, let’s start with the basics.

What Are Lichens?

Lichens are the product of a mutually-beneficial relationship between fungi (the mycobiont) and algae or cyanobacteria (the photobiont).

What does this mean?

Basically, a fungus and an algae or a cyanobacteria join forces for better living, and in the process, they form what we call a lichen.

Lichens on a gravestone at Cortland Rural Cemetery.
Photo by PBM. Used with permission.

Not all fungi and algae/cyanobacteria are well-suited for the lichen life. For fungi which thrive in a lichen relationship, the process of selecting a worthy photobiont is a ruthless one.

A fungi will try to form a partnership with any nearby algae/cyanobacteria. As the partnership is forming, the fungi try to kill off the algae/cyanobacteria. Any algae/cyanobacteria that survives the attempted slaughter is deemed a suitable partner by the fungi and the two will form a lichen together.

What do Lichens Look Like?

Internal Structure

In primitive lichens, the cells of the mycobionts and photobionts are thrown together in a miscellaneous mishmash, but more advanced lichens have distinct layers with specific functions.

Lichen diagram by blog author.
External Appearance

Lichens are strange hybrids which look like neither fungi nor algae/cyanobacteria. There are three main types of lichen: 

fruticose lichens, 
Fruticose lichen photo by Jason Hollinger. A creative commons image.
Source.

foliose lichens, 
Foliose lichen photo by Norbert Nagel. A creative commons image.
Source.

and crustose lichens.

Crustose lichen photo by Roger Griffith. A creative commons image.
Source.
Then, there are countless variations on these basic types.

The physical characteristics of lichens are influenced by lichen acids, byproducts of lichen metabolism. These acids often give a lichen its characteristic color.

Lichens in the sun look almost completely different than lichens on a rainy day. Why? Lichens shrivel up and hibernate when the air is dry to reduce water loss, they open up again to soak up water when the air is moist. Wet days are the best days to observe lichens in all their glory.

Pollution

Lichens absorb water indiscriminately without filtering it. This means they also absorb all the pollutants in the water. Often these poisonous pollutants are too much for the poor lichens to handle, which is why there aren’t many lichens in large cities. The lichens that survive intense pollution tend to be small since their already slow growth is stunted by pollution.
 
Lichen on a NYC street tree. Photo by blog author.
Lichen Reproduction

Some of the lichens I noticed on my hike were covered in dark dots. These dots are a common type of spore-producing growth called disc-shaped apothecia produced by the fungal partner of the lichen for sexual reproduction. Lichens produce spores all year round, and like lichens themselves, the spore production sites are mainly active when wet.
Lichens in the Palisades with spore-producing growths.
Photo by PBM. Used with permission.

The odd thing about lichens is since they are a combination of two organisms, only the fungal part of the lichen can reproduce sexually. The spores the fungi release may grow as a pure fungus, they may die, or they may find a photobiont partner and become lichens, possibly a different type of lichen then their parent.

Lichens also reproduce asexually when small pieces of the mother organism break off and are carried away animals, wind, or water to a new home. To speed along asexual reproduction, lichens produce isidia—small outgrowths which break off easily—and soredia—powdery granules of a few cells which can blow and float to a new location.

Lichen Longevity

Once a lichen does set up shop, it can live for thousands of years. Lichens grow incredibly slowly, so it is a good thing that they can live so long. One lichen in northern Sweden is thought to be over 9,000 years old!

Lichens on a gravestone at Cortland Rural Cemetery.
Photo by PBM. Used with permission.
Now that I’ve learned some lichen basics I hope to start identifying the species of lichens I see. If you know what species any of the lichens in the photos from this post are, please let me know in the comments!


Wednesday, November 30, 2016

Invasive Species: Friends or Foes?

We’ve all heard horror stories about invasive species, but are introduced plants and animals really as bad as the media paints them?

News headlines on invasive species. Image by author. Sources for headlines.
The answer to this question depends on exactly which invasive species we are referring to.

The brown tree snake (Boiga irregularis) is an example of a truly harmful invasive species. 
Brown tree snake. Public domain image. Source.

The brown tree snake arrived on the small Pacific Island of Guam in the late 1940s or early 1950s as a stowaway on military cargo, and has since eaten most of Guam’s birds, lizards, and small mammals. Guam’s fauna never experienced predation by a large snake before, and they are suffering horribly under the reign of the invasive brown tree snake.

In addition to eating Guam’s native species, the brown tree snake causes frequent power outages. How can a snake cause power outages? By climbing pylons and shorting out the power circuits! Climbing pylons is a dangerous hobby as it kills the snake, inconveniences Guam’s citizens, and costs power companies too much money in repairs.

Brown tree snake on top of a fence post. Creative commons image. Source.
The brown tree snake also costs the US military stationed on Guam millions of dollars each year in safety measures to prevent this pesky predator from escaping to another island. So far, this money is well spent as the brown tree snake has not escaped Guam.

The only good thing about the brown tree snake is that it eats Guam’s rats.

But what about another invasive species, garlic mustard (Alliaria petiolata)? I remember when garlic mustard was one of the most hated plants in NYC. Garlic mustard grew in dense monocultures and drove out other plants. Every time I went on a walk I would see huge piles of garlic mustard the parks department ripped out of the soil in an attempt to eradicate this species. Now, I rarely see piles of dead garlic mustard. Instead, I see garlic mustard growing alongside other plants along the park paths. What caused this change?
Garlic mustard. Creative commons image. Source.

 Garlic mustard was deliberately introduced to the United States in 1868 on Long Island for its ability to control erosion and its medicinal properties. While garlic mustard may look innocent and charming with its little white flowers, this plant had serious issues with poisoning its neighbors. 

Sinigrin, the toxic chemical garlic mustard emits, kills nearby plants and mycorrhizal fungi. Mycorrhizal fungi are a type of fungi which colonize the roots of plants and help their plant partners absorb more water and nutrients. Without their mycorrhizal fungi, the lives of plants living near garlic mustard were jeopardized, which allowed garlic mustard to push these plants out. Soon garlic mustard was dominating the forest floor.

Now, garlic mustard has been living in the United States for a long time and it is learning to be a kinder neighbor. U.S. garlic mustard doesn’t emit as much sinigrin as it used to, and the plant can grow next to other species without killing them.

Garlic mustard flowers. Creative commons image. Source.
Why is this?

High levels of sinigrin release, seen when garlic mustard first was colonizing the states, is most beneficial for garlic mustard when the plant is mainly competing with other species. However, when garlic mustard is well established, it mainly competes with itself, which means low levels of sinigrin release are preferable. Low levels of sinigrin emission are currently so favorable for the U.S. garlic mustard population that the genetics of this population changed to make low levels sinigrin release widespread and innate.

Now that garlic mustard has had a chance to settle into its new home, it’s not acting particularly dangerous and invasive anymore, is it?

Purple loosestrife (Lythrum salicaria) and Canadian pondweed (Elodea canadensis) are two other introduced species, like garlic mustard, accused of forming monocultures and driving out native species. After forming dense stands during the first few years of introduction, purple loosestrife and Canadian pondweed populations both declined significantly, like garlic mustard did, and they now live peacefully next to native plants. Non-native species may need a few years to acclimate to their new homes. We may be accusing them of wrongdoing too quickly.

The purple haze in the background of this photo is purple loosestrife.
Photo by PBM. Used with permission.

Admittedly, garlic mustard, purple loosestrife, and Canadian pondweed are not the worst invasive species. These plants don’t hold a candle to the brown tree snake. Are the more wickedly painted invaders, like zebra mussels (Dreissena polymorpha) or tamarisk (Tamarix sp.), ever falsely accused?

News headline on invasive species. Image by author. Sources for headlines.

Yes, non-native species are often blamed for problems we humans caused simply because they are found near where the damage occurred. 


Illustration of a zebra mussel. A public domain image. Source.
Zebra mussels are incriminated for clogging pipes, covering every hard surface underwater, and eliminating endangered freshwater mollusks. The fact is, freshwater mollusks were on the decline long before zebra mussels ever arrived because of habitat degradation and pollution caused by humans. Zebra mussels do compete with these mollusks for food, but it is wrong to blame them for endangering the mollusks. 

Zebra mussels. Creative commons image. Source.
Zebra mussels do cover a large amount of hard surface area underwater, but while doing so, they filter polluted water. As a result of the zebra mussels’ filtering job, the water is clearer, which promotes the growth of aquatic plants. These plants provide cover for fish and invertebrates and help increase their populations. The fish then feed on the zebra mussels and help clear some of the hard surfaces they live on. Zebra mussels also serve as a major food source for waterfowl. 

Yes, zebra mussels may inconvenience water companies by clogging their pipes, but they aren’t the evil species the media makes them out to be.

Zebra mussels on water meter. Public domain image by NOAA. Source.

Tamarisk has a similar story. This small tree is blamed for being a water hog and for destroying native bird habitat. Actually, humans were the ones using all the water. Tamarisk use about the same amount of water as native plants. In addition, tamarisk provides habitat for native birds. This plant isn’t quite as bad as the headlines make it seem.
Tamarisk flowers. Creative commons image. Source.

The whole idea that introduced species must be harmful is a xenophobic attitude. Once a non-native species takes root, it is next to impossible to eradicate. Introduced species are not going away anytime soon either, as international trade and travel just make it easier for species to globe trot. It’s time to accept the innocent immigrants species and the benefits they can offer our ecosystem.

Wednesday, November 16, 2016

The Brain on Coffee

I recently became a coffee drinker, and as I drank my coffee one morning, enjoying how much more awake and alert I felt with every sip, I began to wonder: why does coffee help me wake up and focus? What is caffeine doing to my brain?

Photo by History Underfoot, Used with permission.
Energized by my morning brew, I jumped right into research. Soon I learned many new words (neuroscience papers are superfluously verbose) and why coffee helps most of us feel more human on even the least promising morning.

A drawing of the brain.
A public domain image. Source.

The invigorating effect of coffee can be traced to the caffeine present in the beans. We all know that caffeine is a central nervous system stimulant. But how does it get into our nervous system in the first place? Caffeine can easily cross the blood brain barrier, a screening system which prevents most chemicals from entering the brain, to interact with our neurons. 
Stained neurons.
A creative commons image. Source.

What does that mean?

Before I explain exactly how caffeine interacts with our neurons let’s back up a little and briefly review how our brain works. Our brains are made of neurons which respond to stimulus by sending and receiving neurotransmitters. Neurotransmitters are chemical messages which either trigger neurons to release more neurotransmitters—or stop neurons from releasing more neurotransmitters. The complex patterns of releasing and withholding neurotransmitters are what allow us to move our muscles, to make decisions, and form memories.
A creative commons image. Source.

One end of a neuron—the end which receives neurotransmitters—is made of many branched extensions called dendrites. The dendrites are covered in receptors which interact neurotransmitters. Different types of receptors respond to different neurotransmitters. 

Now, let’s get back to the coffee. Caffeine mainly affects two types of receptors known as the A1 and A2A receptors. These receptors normally receive adenosine, a neurotransmitter which helps us sleep and relax. Caffeine blocks the A1 and A2A receptors and prevents them from receiving adenosine. With less adenosine interacting with our neurons we automatically feel more alert and awake. 
Drawing of neurons.
A public domain image. Source.

Caffeine,  in preventing adenosine from doing its job, has a few side effects like increasing anxiety. People who are prone to anxiety and panic attacks—and first-time coffee drinkers—are more likely to feel nervous after a cup.

Luckily for us regular coffee drinkers, most people’s brains habituate to caffeine very easily, and the caffeine jitters become less pronounced the more frequently one drinks coffee. After my first cup of coffee, I felt a little on edge, but now that I’ve been enjoying coffee daily for about two weeks, I don’t feel nervous after my morning mug.

Vintage coffee can.
A creative commons image. Source.
Caffeine promotes alertness, which is great during the day, but not as pleasant at bedtime. Even if one does manage to fall asleep after drinking coffee in the afternoon, caffeine reduces the amount of deep sleep per night and increases the amount of light sleep. The rapid eye movement (REM) sleep, or dreaming sleep, remains the same regardless of coffee consumption. First-time coffee drinkers are more likely to experience sleep disruption as increased caffeine tolerance reduces the drug’s influence on sleep.

Another thing I learned is exactly how quickly one becomes accustomed to caffeine depends largely on genetics. Some people’s livers metabolize coffee slowly, and since caffeine would remain in their bodies longer, it may have a stronger effect on them. In general, people of Asian and African descent tend to metabolize caffeine more slowly than those of European descent. 
Author's own image.

I have not gotten my DNA sequenced yet, but I’m guessing that my liver metabolizes caffeine fairly quickly because I quickly became habituated to caffeine and my ancestors were European.

Coffee has a few other side effects like excessive urine production, increase in systolic blood pressure, and dilation of the airways. I’ve read that drinking too much coffee can raise the blood pressure to dangerous levels in people with hypertension. (Always do your own research.)
Author's own image.

For people without hypertension or caffeine-induced anxiety, lifelong coffee drinking is suspected to delay the onset of cognitive decline, Parkinson’s disease, and diabetes. One recent study found that drinking coffee reduced the risk of brain tumors in Japanese populations. The benefits of coffee drinking tend to be more pronounced in women.


Unfortunately, these health benefits only apply to lifelong coffee drinkers. Starting to drink coffee as an older adult can possibly increase cognitive decline. People with Parkinson’s disease and diabetes who began to drink coffee after they were afflicted reported no change in their symptoms.

Even if coffee can’t change the symptoms of Parkinson’s or diabetes, it can improve one’s mood. Coffee paired with bread and blue light is one of the top mood improvers! I know next time I’m feeling down try this coffee, bread, and blue light strategy. (Where do I find blue lights?)
Coffee and bread, my breakfast this morning! Author's own image.

Happy coffee drinking to my fellow coffee lovers!

Inspired to learn more about coffee? Check out my post on my other blog, Totally Baroque, about 17th century men and women who couldn’t pass a day without the “drink which drove away drowsiness" here.


Thursday, September 29, 2016

Cemetery Series: The Cemetery Habitat

Cortland Rural Cemetery. Photo Credit to PBM.
Cemeteries are not just for the dead, but for the living. In fact, graveyards serve as safe havens for rare plants and animals. Tombstones in Britain are the only home of some species of endangered lichens. The Calvary Cemetery in north St. Louis, Missouri contains the last original prairie grasses in the area and is one of the few spaces where ground-nesting bees survive. The Wei├čensee Jewish Cemetery in Berlin is home to 608 species of wildlife including an arthropod (Agonum gracilipes) which was thought to be extinct. It’s not extinct! That little invertebrate has been living in a graveyard in the middle of Berlin.
The Trinity Church Cemetery. Photo by author.
Cemeteries are often the only fragments of natural habitat left in cities or areas dominated by agriculture. This makes graveyards vital to the survival of many species.
Author's own image.

The Trinity Church Cemetery. Photo by author.
Wildlife thrives in un-manicured cemeteries and in cemeteries with tombstones placed close together. At the Wei├čensee Jewish Cemetery mentioned above – the place that surprised scientists with the arthropod – most species are found in areas left to grow naturally. Closely-crammed tombstones provide hiding places for animals like foxes and coyotes. Tight spaces between grave monuments also makes it harder to remove sprouting plants, allowing them to grow and prosper.

Kings Chapel Burying Ground. Photo by Author.
Author's own image.
The flora and fauna in cemeteries provide data on many topics like conservation biology, species diversity, and climate change. Managers at some cemeteries embrace the wildlife found among the gravestones and host birdwatching programs or guided hikes through their land. One great example is the Cortland Rural Cemetery in Cortland, New York that offers a self-guided tour on the cemetery featuring the trees and lichen growing there.


Cortland Rural Cemetery. Photo Credit to PBM.

To learn more about cemeteries and science check out my previous posts: Cemetery Geology and Death and the Environment.

The Trinity Church Cemetery. Photo by author.
Sources.