Recently one of the oldest residents of North Branch was killed. The intentional act of taking the life happened in broad daylight at the corner of 10th Ave and Main Street. The victims name was Quercus macrocarpa, more commonly known as the bur oak.
It likely took less than 15 minutes to drop the healthy bur oak that was at least 140 years old. All that remains, at the moment is a broad stump that measures four feet in diameter at its widest point. The fresh cut, exposing the annual growth rings displayed a healthy and sound trunk. This was not a failing tree.
The tree was part of the rich family scrapbook of North Branch. The acorn that produced the giant oak germinated before North Branch was incorporated as a village in 1881. And it was likely growing when the railroad line was put down in 1869. Prior to North Branch being platted, in the surrounding countryside was a blend of oak savanna and wooded lowlands and river bottoms. The bur oak, with its thick corky bark is able to survive frequent grass fires that would have encouraged a landscape of native prairie and burr oak. No tree is more symbolic to the rich ecological history of the area we call North Branch than the bur oak.
We are lucky to have a few remaining giant bur oaks in North Branch. My guess is that the reason this one was cut was simply ignorance of history and the free services the tree has provided.
Recent research out of Stanford University estimates that natural systems around the world provide at least 33 trillion dollars worth of free ecological services. For example a wetland provides flood control, water filtering, a nutrient sink, a carbon sink and provides oxygen at absolutely no cost to us.
The big oak and some large white pines next it, were cut to make room for a fourth bank in North Branch. In the past couple of years North Branch has had other giant, healthy bur oaks cut. More historical artifacts gone.
My guess is that the tree that shaded the Pohl house did not fall into the parking lot plans. It might have served as a wonderful signature landmark for the bank, there will likely be some non-native plantings put in around the bank. My guess is conifers, which are much shorter lived. If average summer temps continue to climb in Minnesota, conifers are not a very good long-term choice. Bur oaks are ideal.
For over a century the giant bur oak provided free shade for those generations of folks who lived in the house that was built near the tree. Its spreading canopy reduced the need for air conditioning or running of fans for the Pohl family and those who lived there before. Its likely it provided shade for pastured cattle of horses prior to a house being built at that location. Bur oaks resist most diseases that affect other oaks. Their deep taproot makes them drought resistant and enables them to stand up to severe winds.
Humans are putting more carbon into the atmosphere than ever before and therefore, compromising the health of natural systems around the world. According to Dr. Lee Frelich, University of Minnesota Forestry Research Associate, a healthy oak is capable of absorbing 100 to 200 pounds of carbon each year. If we assume that the tree was a mature tree for at least 100 years, and it was likely more, and annually absorbed 150 pounds of carbon as an average it would have tied up at least 71/2 tons of carbon plus the carbon tied up in the weight of the tree itself. According to Frelich, the mature oak likely weighed 1-2 tons. That one tree alone absorbed about 10 tons of carbon.
Additionally, in return for the carbon, the tree released oxygen, for you and I to breathe. I would guess that over the years, scores of generations of robins and other songbirds had nested in its strong limbs.
I wonder what are the services of an impermeable asphalt (petroleum product) surface that will not allow any snowmelt or rainfall to soak into the ground. Instead the water will flow off the lot, picking up any salts, oil, gasoline and antifreeze drips and washing them down the storm drain to merge with the namesake of our community, the North Branch of the Sunrise River.
When the ancient oak was about 100 years old, popular singer, Joni Mitchells 1970 hit song, Big Yellow Taxi contained a couple poignant lines:
You dont see what you got until its gone.
They paved paradise and put a parking lot.”