One million. That's the estimated number of ash trees just in Hennepin County on maintained property like parks, yards, boulevards and parking lots. Those one million trees make up about 20 percent of the trees in the county. And throughout Minnesota, there are nearly one billion ash trees. Nearly all of these trees are expected to be infested over the next decade by the emerald ash borer, an invasive beetle from Asia that kills ash trees.
The infestation in Minnesota has already begun. Based on lessons learned from states such as Michigan and Ohio, the number of ash trees becoming infested and dying will expand at an exponential rate and will reach a tipping point that can overwhelm local financial and staffing capabilities. Minnesota may be approaching this tipping point. In St. Paul, four times as many infested trees have been found this spring as were found in all of 2015.
There is no cure for trees infested by the emerald ash borer. Preservation options exist, but due to cost these are typically used only on the largest and most environmentally beneficial ash trees. The rest of our ash trees will die and will need to be removed, and a new generation of trees will need to be planted to maintain our environment and quality of life. Whether we choose a proactive or a reactive approach to deal with this epidemic, the costs will be significant. But experiences from other communities demonstrate that a proactive investment now will save us millions of dollars later.
Why replace ash trees? Like roads, bridges, sewers and water mains, trees are important infrastructure that require support and maintenance. Their benefits to the community include making our air healthier by filtering particulate matter and converting carbon dioxide — a greenhouse gas — to oxygen. They protect the environment by reducing stormwater runoff, and their cooling summer shade reduces the urban heat-island effect and the need for air conditioning. And their aesthetic value provides an attractive environment that refreshes our minds and spirits.
We're about to see our once-abundant ash trees become rare. If we don't act now, we will also witness a dramatic degradation of our environment and a significant loss of our tree canopy in both rural and urban areas. This statewide problem requires state action to fund a holistic solution. With state support, we can preserve the most environmentally valuable ash trees, remove infested and dying trees that threaten public safety on our streets and in our parks, and plant a diversity of new trees to replace the loss and restore our environment.
Starting now, rather than waiting for the crisis to accelerate, is smarter and more practical. Several bills have been introduced in the current legislative session that provide funding to local governments to address the impact of emerald ash borer. I urge the Legislature to act now before we are faced with streets, boulevards and parks full of hazardous dead trees — or devoid of trees altogether. Those of us who lived through the Dutch elm epidemic decades ago know this is the right course for Minnesota.
Peter McLaughlin is a Hennepin County commissioner.
