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A new branch office for Minneapolis Parks: tree cop

Minneapolis Parks' newest branch office: tree cop
MinnPost photo by Mike Dvorak
Craig Pinkalla: “Trees are another city infrastructure. You wouldn’t want someone to cut through a gas line. We want to get people to think tree roots are just as important.”

Don’t call Minneapolis Park and Recreation's new tree cop a “tree cop.”

To Craig Pinkalla, the title sounds too, well, adversarial. He prefers the official title for the park system's newly created position: forestry preservation coordinator. 

Whatever you call him, though, Pinkalla’s job is to serve and protect the city’s thousands of boulevard trees (i.e. those between the sidewalk and the street) to make sure they aren’t being damaged by contractors, city workers or homeowners.

And though Pinkalla doesn’t use the term “tree cop,” others on the park staff do. Ralph Sievert, the park system’s director of forestry, said the idea has been around for a while: devoting a single staffer to review plans, work with city public works, and visit sidewalk and street projects to help crews figure out how to do less damage to boulevard trees during construction.

It turns out the city has lost enough of its canopy — first to Dutch elm disease and now the emerald ash borer — that it feels it can’t afford to lose any more to an overzealous backhoe operator. “With ash trees already in jeopardy, it’s more important than ever to keep as many that are success stories on the landscape,” Pinkalla said.

Yet it took a catastrophic event to get the tree cop on the beat. On the evening of June 21, 2013, a violent thunderstorm brought up to 3 inches of rain and winds near 60 mph. Preceded by a day of high winds and heavy rainfall, the storm moved from the northwest corner of the city to the southeast corner, hitting neighborhoods in the southern half of the city the hardest. Hundreds of thousands of residents in the region were left without power, and an estimated 1,800 public trees were lost.

In the aftermath, foresters noticed what seemed like a higher-than-expected loss of boulevard trees, many due to what foresters call “windthrows” — trees that are uprooted or partially tipped. They then began to sense that many of the damaged trees were on boulevards where sidewalk repairs had recently been made.

To check their hypothesis, the park board and the Minneapolis Public Works Department commissioned a study by the University of Minnesota Department of Forest Resources. Led by Professor Gary Johnson, the researchers surveyed all trees in the storm path, collecting information on size, type of species and the width of the boulevard where they were growing. It then compared that survey with records of sidewalk work. 

The study, presented to the park board and City Council earlier this year, concluded there was indeed a connection between construction work and tree failures. Two factors, it turns out, contributed to tree failures: whether trees were adjacent to a sidewalk or utility work; and whether trees were planted on boulevards that were particularly narrow. That is, a tree planted in a 4-foot-wide boulevard was more vulnerable than one planted on a boulevard that is 8 feet wide. Even then, however, trees on narrow boulevards were less likely to fail if no sidewalk or utility work had been done nearby. 

As part of the findings, Johnson’s team made several recommendations, including the suggestion that construction work threatening tree roots shouldn’t be done without consulting a forester or arborists, since damaging roots by haphazard cutting can jeopardize trees.  

That's where Craig Pinkalla, tree cop, comes in.

“Trees are another city infrastructure,” he said last week. “You wouldn’t want someone to cut through a gas line. We want to get people to think tree roots are just as important.”

Pinkalla, who received his urban forestry degree from the University of Wisconsin-Stevens Point and did similar tree cop work in Milwaukee, meets regularly with contractors selected to replace sidewalks for the city of Minneapolis. That’s when he gives them information about how best to deal with tree roots in the way of their projects. He frequently visits those sites to advise on which roots can safely be cut and which cannot.

As Sievert describes it, Pinkalla might say: “That root you can cut, but don’t cut that one. It’s an anchor root.” If damage to significant roots cannot be avoided, he can order the tree removed for safety reasons.

Minneapolis, with an estimated 50,000 park trees and 200,000 street trees, has a special relationship with its tree canopy. In his book “City of Parks,” David C. Smith writes that park board founding father Charles Loring lobbied the state Legislature in 1887 to give the board control over the planting and care of trees along all city streets, not just those in parks or on parkways. At one point, he hired school boys to remove campaign posters nailed to tree trunks.

“I got two sheriffs, a mayor and 10 alderman,” one boy said while presenting a fistful of fliers to Loring for payment. The park board staff led the battle with Dutch elm disease, even winning the authority to remove infested trees from private property to stem the spread. It also began the diversification of tree species as a bulwark against species-specific pests such as the emerald ash borer, which appeared in 2010.  And today it remains in charge of the city’s public trees on both parkland and city property.

Needless to say, the park board staff takes trees pretty seriously. It planted more than 5,900 trees each year between 2010 and 2014, and plans to increase that number to 8,500 this year, at a cost of roughly $900,000. When the park board's Tree Advisory Commission made the recommendation to create Pinkalla's position, it noted that the new position would “give trees a seat at the table.”

Maybe not the trees, exactly, but the tree cop, or whatever they want to call him.  

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Comments (1)

Tree Cop? More like Tree Paramilitary

The trouble with Minneapolis urban forestry management, under the leadership of Ralph Sievert, is that Mr. Sievert has chosen to equip his team with two, and only two tools: a chain saw, and a wood chipper. (Okay, three: a dump truck too.)

Since moving to Minneapolis 20 years ago, we have witnessed the loss of half of the urban canopy, under Mr. Sievert's leadership. The elm tree population is pretty much gone, because Ralph refused to coordinate with local tree care service companies such as Rainbow or Top Notch, to maintain a sustainable injection program. He insisted that sanitation - the removal of diseased trees - alone would preserve the elm population. Injecting each and every elm tree would be too costly and labor-intensive, according to Ralph.

So instead, Ralph and his team chose to cut down each and every boulevard elm, one by one, over the course of years, until only a fraction presently remain. Now you tell me: which is more costly or labor-intensive: one guy with a Ford Ranger pickup, a drill, and some fungicide, going around injecting the trees, which (when done properly) protects it for three seasons, and doing so on a rotational basis ... OR bringing in a crew of a dozen or more, with chain saws, cranes and a tree grinder, closing off an entire street for day, and taking down a mature tree ... one tree .... and then returning to the same site again and again and again, a week, or a month or a year later, until before long the entire block has been felled?

And THEN replace them them later with (drum roll please ....) ASH TREES!! (And in fairness, a few other varieties. Even still, half or more of the replanted saplings haven't survived the first year.)

This is the kind of urban forest management we have witnessed, and paid for with our property taxes, over the past 20 years.

And NOW the ash trees are threatened (not necessarily infested, just threatened) with emerald ash bore pests - pests which could be eradicated with insecticides. But no. What's Ralphie's solution? Get out the ol' chain saw and wood chipper!

Ralph's team is a lot like the U.S. military: they're great at showing their military might, bombing, shooting and killing whole populations, but not so great at rebuilding, or protecting what's left. And like the military, when the only tool in your tool shed is a hammer (or in this case, a chain saw), then everything you see is a nail.