SPECIAL TO THE MID-COUNTY MEMO
We’re quickly turning a corner in our understanding about trees as people who live in a city. There was a time when many of us may have seen trees only for their problems. We’d heard stories of trees breaking sidewalks or cracking pipes underground, and that’s not even to mention that they drop leaves every year. Why isn’t that a deal breaker for everyone—what am I missing, you might ask?
Relative to the number of trees we could plant, there is a very short list of infamous “sidewalk busters” that are no good as street trees. That list includes such trees as sweet gum (Liquidambar styraciflua), poplar and cottonwood (Populus spp.) and Norway maple (Acer platanoides), to name a few, none of which are on the lists of approved street trees from the city of Portland because of their tendency to produce shallow roots. Mistakes were made in the past, and the wrong trees were planted in the wrong places, but urban forestry has made huge strides over the past couple of decades in terms of clarifying which trees is the right tree for the right place. In other words, any permitted tree being planted at this point by Friends of Trees or the Bureau of Environmental Services will be tailored to the amount of space along the street and whether there is high-voltage power lines overhead.
What about the pipes? Don’t trees bust open utility lines running underground? That used to be the perception, but urban foresters now know that roots are opportunistic and not invasive. In other words, if your sewer pipes are scoped and tree roots are found, it’s because the aging clay pipes that were once used had cracked and started leaking, and the roots decided to investigate a new source of fertilizer. Likewise, this can happen if there is a leak in a water line, as roots certainly need water. Although roots may be found to have invaded sewer or water pipes, it’s important to understand that they’re drawing attention to a problem as opposed to causing it. On the other hand, roots have no need or interest whatsoever in natural gas, electric, communication or other lines, meaning there’s really no conflict at all between tree roots and underground utilities.
Regarding leaves, sometimes it’s a matter of perspective when it comes to judging whether something is a help or a hindrance. First off, there are several evergreen varieties that lose leaves from time to time, but they do not do so in a huge dump like deciduous trees do in the fall. There is also the ancient ginkgo tree that loses its leaves over the course of about one week, meaning you may have to rake only once (and that’s if you don’t appreciate the beautiful butter-yellow blanket of leaves around the base of a dormant ginkgo). Another perspective is that those leaves are the best imaginable soil-builders nature can provide. Rake them up, pile them in your flower or veggie beds right after they fall and you’ll be amazed how rich and fertile your garden soil is when you go to plant the following spring.
At this point, the evidence shows that trees are not only an asset but also part of the solution to many of society’s problems. How can I as an individual do my part to address climate change? Plant trees. What can I do to mitigate the particulate matter coming from the highway I live near that contributes to higher rates of asthma and respiratory problems in my community? Plant trees. What can help us keep contaminated water from running into the Willamette River? Trees. What has been shown to slow traffic on my block? Trees. Reduce crime? Trees. Lower my heating and cooling bills? Trees. Are you starting to see a pattern emerge?
The moral of this story is that it’s time we realize that trees are far from the liability they may have been seen as in years past. If you’re interested in being part of the solution going forward, why not consider planting a tree next season with Friends of Trees? If you’re already sold on the many benefits trees provide and don’t have space for any more, consider helping Friends of Trees monitor recently planted trees in your neighborhood as a volunteer summer inspector. If you’re good at coordinating events or would just be interested in seeing more trees in your immediate community, consider becoming the neighborhood coordinator for your community. Help with coordinating planting events is needed in the Argay, Parkrose, Russell and Wilkes neighborhoods.
More information about any of these volunteer roles is at friendsoftrees.org or by contacting Andrew at firstname.lastname@example.org or 503-467-2518. n
Andrew Land is the Neighborhood Trees Senior Spet with Friends of Trees