Think back to the last time you were under the branches of a tree - did you notice its presence, or simply accept it as part of the background? Trees are a normal part of everyday life, fixtures in the background of our day-to-day docu-dramas. It is easy to overlook them.
However, trees are serving us every moment of the day, and are an essential part of our urban ecosystems. You may know that trees give us shade, or if you mastered photosynthesis in science class, oxygen to breathe. You might even be keeping up with the revolutionary finding that trees communicate with and cooperate with one another through fungi and intricate root systems. But did you know trees are also tied to rainfall, cases of asthma in cities, and your emotional well-being?
Even if your only association with trees involves the car you left parked under it covered in bird droppings, it can be pretty humbling to understand the wide range of daily tasks trees perform for us to make life as we know it happen – with or without the extra car wash fee.
Filter Out City Smog
Trees take in toxins so you don’t have to breathe them in. Along with removing carbon dioxide from the atmosphere, trees taken in the associated pollutants and trap them in their tissues. Urban trees tend to have shorter lifespans than rural trees due to this job description, making them the unsung martyrs of city life. This effect has a measurable effect on people in cities. It has been found that asthma rates among children are lower in streets with trees than those without. The next time you leave your Lyft idling because you’re still not ready, thank your trees for absorbing those exhaust toxins so you don’t have to.
Decrease Your Stress
If you have ever felt a strong urge to go to a park or the mountains, this one is easy to relate to. Natural spaces keep us in the present moment, free from the distractions of our digitized life. Called the “nature effect”, research has shown that trees are particularly strong predictors of sending us to this zen state. The increased density of greenery can lower our pulse rate and measurably reduce muscle tension, along with fostering social connection and encouraging physical activity. The next time you have the option between taking a detour through a park or your neighborhood to get to work, opt for the long way for some immersive tree time.
Create a Drastic Cooling Effect
There’s a reason that big cats lounge under the sparse shade of trees on the Savannah. The temperature difference between shade and direct sunlight can change the odds of survival. Much like lions and cheetahs, humans are not exactly adapted to constant direct sunlight. As our trees disappear into the concrete of sidewalks and Starbucks awnings, less sunlight can be absorbed into green spaces and is hurled back off the concrete as heat. This phenomenon, known as the “urban head island effect”, has been credited with a difference of as much as 20 degrees Fahrenheit between city center and surrounding natural spaces. Trees greatly offset this effect, and is why the city of Sacramento currently offers residents up to 10 free trees to reduce their summer cooling bills.
Make it Rain
Can living things control the weather? New research from UCLA suggests that trees can. Another gold star if you remember this from biology – trees transpirate during photosynthesis, or breathe out water. In a given environment, trees add water to the air around them, creating the humidifying effect credited to glowy, dewy skin tones everywhere.
This effect is nowhere more pronounced than in the world’s largest tree hub, the Amazon Rainforest. Months before rain is brought in from the ocean, the leaves from billions of trees release water vapor, creating low-lying clouds of vapor that cool and condense, turning into a liquid and falling as rain. The next time you contribute to an organization that fights deforestation, know that you are helping the “lungs of the earth” both stabilize oxygen levels and prevent widespread drought.
Hold the Land Together
If you have ever visited a desert in the southwest, you’ll likely remember that not many trees can be found there. Joshua Tree photo shoots and picturesque oases aside, trees are not what deserts are characterized by. There is a reason why. When trees are uprooted or can no longer survive, their extensive root systems disappear as well. In an area as arid and dry as the American Southwest, the grasses and other small plants that could replace the trees cannot survive. Their tiny roots dry up when the rain stops falling, and what is left behind is a desert landscape in a process called desertification. In fact, historians have found that the early elimination of trees due extensive logging and overgrazing by early Spanish settlers contributed greatly to the modern-day dry, arid climate of states like Arizona.
Trees as #ConservationGoals
For all these reasons and many more, integrating more trees into our cities has become a vision of the future for progressive places. Fortunately for the United States, conservation has gained a relatively large following compared to many other countries. With the introduction of the National Parks in the late 1800’s, protection and preservation of wooded areas was embedded into American ideals. While our relationship with trees is fraught with challenges as our population and the demand on resource consumption and land grows, we have a rich history of conservation to look back upon.
In many other places, deforestation for short-term economic gain is the current reality for growing economies. Those who recognize the importance of trees to the long-term survival of their country and the world are likely to be ridiculed, jailed, or even killed.
From this struggle, heroes have emerged, like the late environmentalist Wangari Maathai of Kenya. She began the Green Belt Movement in the 1980’s with the simple concept that planting trees could bring the landscape, and connected vitality of the people, back to life. It did. The success and expansion of organizations like the Green Belt Movement speak to the promise and impact of trees for all that they do.