I worked for the Minneapolis Park Board in the forestry division for 34 years, and for all of those 34 years we were concerned about the impact of massive root cutting on our boulevard trees during street construction and sidewalk replacement ("Falling trees blamed on sidewalk work," May 14).
None of our staff had physics degrees during my tenure, but we were cognizant of a simple law of nature — the stability of trees is dependent on a healthy root system. Cut off anchoring roots, and the stability of the tree becomes precarious. We did not need a $30,000 study to arrive at this conclusion. After curb and sidewalk repair, the boulevard trees were susceptible to toppling over even in winds that they would easily tolerate before the root cutting — and plenty of them did topple.
Year after year the forestry staff addressed the issues mentioned in the article to no avail. We even assigned a condition to the trees that succumbed to the root cutting. We labeled these tree fatalities "cementitis."
We felt the very best solution to the problem would be to reduce the width of city sidewalks from 6 feet to 4 feet. Ninety percent of the city's boulevard space is 4 feet wide. Reducing the sidewalks to a 4-foot width would not only save the boulevard trees from getting their roots hacked off and give the trees a larger growing space, but it also would save a fortune for property owners who are assessed for the repairs to sidewalks uplifted from tree roots. Unfortunately, apparently city ordinance calls for sidewalks to be 6 feet wide, so our reduced sidewalk width idea was discarded. There are some 4-foot-wide sidewalks throughout the city, however, and they work just fine.
In light of the 3,000 trees that were toppled last year due to sidewalk work, I would say it is time to change the sidewalk ordinance.
