My week started off listening to a podcast on my way to work, and the topic being discussed was Climate Change. The person talking brought up Negative Emissions Technology as a possible solution to Climate Change. Negative Emissions refers to developing technology to pull carbon dioxide out of the atmosphere and store it in the soil. This topic frustrates me as an example of humans trying to over-complicate things in order to make a profit, because you know what does exactly this (pulls carbon dioxide out of the air and buries it in the soil)? TREES.
As I start yelling “trees” at no one, as I’m on the only one in my electric car, I stare out of the windshield at the trees that I’m passing and wonder how often I’ve taken for granted everything that our quiet giant neighbors do for us. My mind drifts to Shel Silverstein’s Giving Tree book, and I remember how much I resented the boy in the story who grew up and took the tree’s branches and trunk to leave behind only a resting stump. Even though the story said the tree was still happy, I found that hard to imagine. And I started to wonder of all of my possessions over the years how many trees were cut down for things that I didn’t really need – when what I really need is clean air and branches to play in and rest under.
Later in the week, I find myself at a Christmas Tree Farm… Saw in hand, my family picks our favorite tree, cuts it down and brings it into our house, where it is currently adorned with lights, ribbons, and family memories. I’ve been staring at this tree, central to celebrating Christmas in the 21st century, and feeling very conflicted that I turned a carbon sink into a carbon source to decorate my living room. My understanding of trees in the fight to save the planet from Climate Change is new, and I haven’t previously thought about a tree in such a way. Which makes me wonder – what else don’t I know about trees and what else am I taking for granted?
This post is for my Christmas Tree – that I didn’t cut it down for just a holiday tradition but instead that it serves as inspiration to learn more about trees and the benefits they provide to us at no cost, to understand the current threats trees face across our planet, and to share what we can do to protect them today.
Why are Trees Important?
Trees don’t boast about their usefulness, nor do they have a price tag. But, trees generate a profit after they are cut down. And money does boast. The problem – living trees benefit everyone including past, present, and future generations, but once they are cut down, they benefit only a few. Perhaps we should consider paying trees for their service; maybe that would fit better into our model of how we think the world should work.
1) Trees Provide Food – A quick list of favorite foods that come from trees: Maple Syrup, Walnuts, Pistachios, Brazil Nuts, Pecans, Almonds, Cashews, Cocoa, Nutmeg, Olives, Coconuts, Figs, Dates, Grapefruits, Apples, Bananas, Pears, Peaches, Oranges, Lemons, Limes, Apricots, Nectarines, Magos, Papaya, Pineapple, Cherry, Plums, Mulberries, Cinnamon, Cloves, and Avocados
2) Trees Provide Oxygen – Plants take in carbon dioxide, water, and sunlight to create oxygen and sugar (photosynthesis). Humans need both the oxygen and sugar. In order to continue growing, (trees themselves are also metabolically active) trees use a portion of their own sugar and oxygen. The remaining oxygen is released into the atmosphere. Most of the earth’s oxygen is actually created by plankton (tiny plants in the ocean), but trees make a significant contribution.
3) Trees Remove Pollutants from the Air – While trees intentionally absorb carbon dioxide from the atmosphere, they also unintentionally absorb and remove Sulfur Dioxide (a by-product from burning coal), Ozone and Nitrogen Oxides (created from internal combustion automotive engines), and particulates (small particles in the air which are a by-product of burning fuel). Trees leave us with cleaner air to breathe despite our intentional pollution.
4) Trees Cool the Air Temperature – Photosynthesis occurs in the leaves which require water. The tree moves water from the root systems up into the leaves where sunlight heats the water, and the vapor is released into the atmosphere. This increase in atmospheric moisture and cools the air.
5) Trees Store Carbon Dioxide and Aid in the Fight Against Climate Change – As mentioned above, for photosynthesis to occur, trees pull carbon dioxide out of the atmosphere. A small tree can absorb 13 pounds of CO2 in a year, while a large tree can store up to 48 pounds. In total, current trees in the US are responsible for removing approximately 25% of carbon emissions resulting from human activity (energy creation and transportation). If we planted more trees, we could increase this percentage even further.
6) Trees Reduce the Cost of Air Conditioning a Home – Trees planted in the right location can provide shade for a home and keep it cooler without requiring as much air conditioning.
7) Trees Block the Wind – Have you ever driven on I90 across Minnesota and South Dakota in the winter? Even a little bit of snow blows across the road and creates white-out conditions. You know what would be a great investment along this Interstate? Trees! Lots and lots of pine trees to block the wind.
8) Trees Improve Water Quality – Trees first provide a barrier that rain needs to pass through before hitting the ground, which slows the falling water down. Then the roots of the tree keep the soil in place and prevent erosion during the rainfall. This keeps soil out of streams and keeps our drinking water cleaner. Trees also reduce the potential for flooding and the resulting storm water runoff. One large tree can suck up to 100 gallons out of the ground in one day. As the tree removes water from the ground, the roots also filter the water, which moves up the trunk to the leaves where clean water is returned to the air. Trees help us keep the water clean just as they work to keep to the air clean.
9) Trees Provide Green Space – Green Space in our city-environments have a direct impact on reducing our blood pressure, slowing our heart rate, and dropping stress levels. Get off your computer and phone and take your lunch break outside. Go for a walk amongst the trees.
10) Trees Mark the Seasons – Trees probably get the most attention in the Fall with their vibrant colors, but I love Spring just as much when the leaves first pop out and have a brilliant and fresh green color before it dulls as the months of Summer wear on.
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Lifespan of a Tree
The basics of tree anatomy are taught in our early years of education, so we might think we know everything there is to know about trees. But trees are living, so of course they are more complex than just the parts that what we can see - trunks, branches, and leaves.
Trees have resided on Planet Earth for more than 300 million years. One tree can outlive not just human generations but human civilizations. The oldest known tree is Methuselah, a Great Basin Bristlecone Pine in California’s White Mountains. This tree is 5,064 years old. When this tree was a seedling, humans were inventing the wheel and Egyptians were developing hieroglyphics. Think about that for a moment – this tree has lived through most of recorded human history. This tree provided us with clean air, clean water, and oxygen for more than 5,000 years, and has helped reduce carbon emissions for our entire history of energy generation and internal combustion engine transportation. How could we ever come up with a price tag for what this tree is worth for its service to our species?
Currently, there are more than 60,000 types of trees living across our planet. Not all trees will live to be 5,000 years old, but trees are the longest living organism on Earth, and they don’t die of “old age.” Trees have the ability to get cancer, but the tumors don’t metastasize (move to another part of the tree) because the cells within the tree don’t move as they do in animals. Trees are also at less risk for DNA damage compared with animals, because they maintain a safe copy of DNA that is used to replaced damaged cells, if needed. Trees also have a natural period of dormancy annually when the lose their leaves and decrease their growth and energy demands. This period of hibernation slows down the trees' aging process. One other consideration in the age of a tree is that the majority of the tree is non-living (non-metabolically active). Only 1% of a tree is alive – the leaves, buds, roots, and a thin layer just underneath the bark. The rest is woody, structural, and includes tunnels through which water and nutrients are transported from the roots to the living parts of the tree.
So how can a tree die? Trees are susceptible to windstorms, lighting, fire, insects, disease, extreme cold and extreme drought, too much water, lack of sunlight, fungi, and being cut down by an axe. If a tree can avoid or adapt resistance to these factors, it will continue to live. And as the tree lives, it will continue to provide valuable services to life on our planet. How lucky we are that trees are so resilient.
Trees Interact, Communicate, and Care for Other Trees
In addition to having extremely long lifespans, trees communicate with and care for other trees in the forest and together have collective intelligence, like how we think of social insects like ants and bees. It’s hard for us to easily observe these abilities of trees because most of it happens underground and at ultra-slow-motion time scales. I heard about tree communication for the first time in an NPR (National Public Radio) Podcast. I struggled through it, because it was the exact opposite of how I pictured trees as majestic, still, and quiet forms of life that I assumed lived solitary lives. This is a real thing though, and although the tree is quiet, it very much interacts with, depends on, and cares for its neighbors in the forest.
The roots underground in a forest form a “wood-wide web” of sorts. Fungi form channels between roots of different trees. Fungi and the trees’ roots have a symbiotic relationship. Fungi enjoys the tree’s sugar, and the fungi increase the trees’ ability to absorb more water and nutrients from the soil. Additionally, these channels provided by the fungi create an underground network connecting trees throughout the forest. Trees use these channels to share water and nutrients with each other. “Mothering” trees pump sugar through the networks which is vital for seedling survival. Trees also use these networks to send chemical, hormonal, and even electrical signals to one other, similar to our nervous system. Trees send warnings of danger to each other of for diseases, insect attacks, and drought. When this signal is received, trees will change their behavior to either avoid or resist the threat.
A tree might also communicate through the air using pheromones scent signals. For example, when an caterpillar attacks an apple tree tree, the tree sends chemicals to their leaves that attract caterpillar-eating birds. The tree will also send a signal to nearby trees to prepare a similar defense. When Elms and Pine Trees are under attack, they send a signal to attract wasps which will lay their eggs inside the caterpillar and eat the caterpillar from the inside out. A defensive move on a slower time scale than we typically think of during war, but clever and clearly effective, as no human has yet lived 5,000 years.
Current Threats to Trees
Despite the resilience of trees, their survival in today’s age is very dependent on actions of our human species. Earth has almost 50% fewer trees than it did 12,000 years ago. More than 90% of the ancient redwoods (the oldest and tallest of the trees) have been cut down. Forests currently cover 30% of the Earth’s land; but forest the size England are lost each year due to deforestation. The Rain Forests could completely disappear in 100 years with our current rate of deforestation. Brazil is at its highest rate of Rain Forest deforestation in 10 years, with 3,050 square miles being cut down between the summers of 2017 and 2018. Unfortunately, trees have yet to evolve to find a chemical that chases away (or eats) humans with axes and saws.
Living trees are carbon dioxide sinks – they pull carbon dioxide out of the air and reduce the impact of human-caused carbon dioxide emissions. The two largest sources of carbon dioxide emissions are energy generation (from fossil fuels) and transportation. The third largest impact on carbon emissions is deforestation. For some reason, humans are cutting down the free “machines” that are working hard to combat climate change caused by humans. I don’t want to hear the phrase “negative emissions” technology again – we need to be talking about what we can do to protect our trees instead! To me, this is the same as trying to create technology to pollinate plants after the bees die. Why are we putting our energy into that – we should be focusing on not using pesticides and killing bees… Pick the easy the solution…
Another threat for trees is the impact of climate change. As climate change increases in intensity, drought occurrences are leading to increases in wild fires, which also threaten our tree population. Also, changing climate is leading to new invasive native and exotic pests and diseases which are attacking trees faster than they can evolve a worthy defense.
Save The Trees!
I’m assuming you’ve “knocked on wood” for luck at some point in your life. Have you ever wondered where this expression comes from? A pagan would tap on a tree to summon the protective spirits that resided within them. Those protective spirits might not live within the tree, but we all need to knock on wood and become the protective spirits for the trees starting now. What can you do to help?
1) Provide special protection for older trees – mature, larger and well-established trees are providing benefits (shade, water, and nutrients) to the younger trees in the forest. Don’t cut an older tree down unless it is required due to disease or infestation. Educate your neighbors that have older trees to ensure they know the benefits of keeping that older tree around for another few generations, so they aren’t tempted to cut it down.
2) Pay attention to how you use tree-based products, and work to cut back your use. Don’t use paper towels to dry your hands and replace them with cloths for cleaning your house. Replace napkins with cloths, and paper bags with re-usable lunch boxes or bags. Think before you print and use recycled paper. Replace paper bills with electronic communication, and bring a re-usable coffee mug instead of a paper cup.
3) Two of the reasons for Rain Forests being cut down are to make room for cattle ranches and oil palm fruit trees. Consider cutting back how much beef you are eating (a healthy choice for your heart as well) but if you do eat beef, ensure that you know where the meat is coming from and don’t eat it if it’s from the Rain Forest. Eat local meat. Read labels for household and food products for the presence of Palm Oil, and don’t buy those items.
4) Plant more trees in your yard. The best choices are local trees that will grow large to clean the air and water for generations to come.
You might think of yourself as a “city-person” and maybe you’re not a fan of hiking through the forest. But even if you spend your entire day inside walls, you breathed oxygen all day and you drank water or a beverage that contained water. The “city” didn’t make these gifts – a tree did. We depend on nature for everything we need. We can’t take our trees for granted – our survival depends on the health and protection of our forests throughout the world.
Additional Sources For More Information About Trees
25 Kickass Interesting Facts About Trees/
Potentially Immortal Why Some Plants Can Live Hundreds Even Thousands of Years
The Hidden Life of Trees: What They Feel, How They Communicate,
Understand what the Paris Climate Agreement is, why a global agreement is necessary to fight climate change, and why it matters that the United States remain in the agreement.