Planting Trees For People & The Planet
During the recent heat dome event, walking through my increasingly urban neighborhood made the value of neighborhood trees clear. Even as temperatures soared, places where trees provided shade stayed noticeably cooler than nearby streets and sidewalks, which reached egg-cooking heat. In homes without shade, indoor temperatures were in the 90s, proving dangerous for elderly occupants. Shortly afterward, I was asked to make a determination about a tall cedar that’s impinging on two neighboring homes. Five years ago, an arborist had noted that both neighbors had added on structures that crowded the large trunk of the cedar, in one case cutting into the tree’s base to make room for the building extension. Now the tree is slowly pushing over the power pole on one property, crushing gutters and breaking the roof soffits, and buckling the deck on the other.
I live in a neighborhood of mobile and manufactured homes, some brand new, most older. Decades ago, the neighborhood was surrounded by Doug firs and cedars, many of which were left in place as the mobile home park developed. As the park grew, so did the trees. Now, there’s a lot of pressure to remove the oldest and largest evergreen trees. Huge widow maker limbs can fall during wind storms. After some sixty years, an over-planted row of firs is full of dead and damaged trees with roots unstabilized by increasing building and water drainage, and some have fallen on home roofs. Wildfire protection warnings encourage removal of evergreen trees that overhang homes, which can help fires hop from roof to roof. So what do I do?
The Value Of A Tree
Like most of the way-too-many mature evergreens in the neighborhood, this random cedar was probably a volunteer that was simply left in place despite the fact that it would become a nuisance if not a hazard over time. Removing huge, maturing trees like this one is expensive, no doubt. Not only will it cost thousands of dollars to have the tree taken down, but its removal will displace a significant amount of the wildlife that makes this urban neighborhood feel like a country oasis. We love our birds and squirrels (well, mostly) and every big tree that comes down takes away food and shelter for the critters. Equally important is the amount of air cleaning and oxygen production large trees provide. Last and least, the cedar protects my home from blistering afternoon sun.
I’ve been pondering all this and grieving that thoughtless planting and planning has created such a sad situation, where majestic, life-supporting trees are cut down because they impinge on human preferences. As with so many equity issues, most of us talk a good talk about loving and protecting trees, but when it comes to our own property, or our neighborhood, or our cities, or our highways, or even our parks, trees almost always lose out to “progress”. Just how much do we actually value trees? Do we truly recognize how much trees contribute to our comfort and well being? Most of us vaguely understand that trees support every living thing on our planet, from bacteria to behemoths like elephants and whales. We may know that trees convert carbon dioxide and other harmful-to-humans gasses into the oxygen we breathe and the natural sugars that nourish trees and create autumn foliage colors. We might even realize that, in some situations, trees can even promote rainfall.
Even A Single Tree
A big, flourishing tree like the cedar next door can provide enough oxygen to keep four of us alive all day. Over the course of a year, a tree like this absorbs and store nearly 50 pounds of carbon, some in its wood, some deep in the soil. Its shade and wind protection are increasingly important as weather becomes more extreme. This is especially true in urban settings, where even highly artificial parks provide measurable benefits. According to a recent study, even narrow, raggedy roadside verges host surprisingly diverse microbial communities that sequester carbon and filter pollutants from soil, air and water. Even the simplest urban greenspaces form similarly complex ecosystems that also promote human mental and physical wellbeing.
A new study from American University shows that even a single tree can reduce pollution, mitigate neighborhood noise, and lower ambient temperatures for hours in urban settings. Another recent study measured temperature differences in urban neighborhoods just a few blocks apart. Not surprisingly, heavily treed neighborhoods were cooler and cleaner, while those without trees and greenery were far less pleasant. Now guess which were wealthy neighborhoods and which were lower income? Correct.
How We Can Protect Our Trees
All this makes me curious about how we can support more trees and greenspaces in our neighborhoods, towns and cities. A quick search brings up many options, notably the Arbor Day Foundation, which offers free saplings of fast-growing trees to all who request them. True, the saplings are tiny, but I’ve had very good luck in growing them on and transplanting them with school kids over the years. Many people know about that program, but fewer are aware of the Arbor Day Foundation’s full range of opportunities to get involved in tree planting initiatives pretty much everywhere. The Community Tree Recovery program promotes healing and replacing trees after natural disasters. Tree City USA connects us to community forestry projects and helps us start one locally if need be. Tree Campus K-12 offers tree stewardship programs to schools, helping kids connect human quality of life with the health and wellbeing of trees. There’s a lot more to explore, so check it out:
Unless you can provide ample water, high summer isn’t the greatest time to plant trees. However, it’s a great time to locate both private and public places where trees would be a blessing. It’s also a good time to do some research and make a list of appropriate trees for each spot. Appropriate placement is a good way to avoid having to kill a healthy tree because it was planted in the wrong place. Remember that trees grow, so make sure they’ll have both ground space and air space to reach their full potential. Don’t place trees too near a home; shade trees should be placed far enough away that branches won’t touch the building even at maturity. Be aware of overhead wires and the overhanging, ever expanding canopy of existing trees.
A good source for partnering plants and placement in the Maritime Northwest is the Great Plant Picks website. Created by a panel of local and regional plant professionals, this annually updated site offer lists for many situations along with cultural information, including accurate height and width at 10 years and at maturity. So let’s all pledge to partner with trees, helping to care for existing trees and planting new ones whenever possible. Onward, right?