Trees

South St. Paul’s Urban Forest

An urban forest is a wooded area or collection of trees located in a city, town, or suburb. According to the US Forest Service, over 141 million acres of America’s forests are located in cities and towns. Urban forests are considered “green infrastructure,” as trees clean the air, slow down and absorb stormwater, decrease erosion, increase property value, and save homeowners money by providing shade and reducing air conditioning costs. They also improve physical and mental health and provide habitat for wildlife.

The trees in the City of South St. Paul have an estimated value of about $6.4 million, according to a survey conducted by Davey Resource Group in 2017. This includes:

  • Aesthetic and other benefits
  • Air quality improvement (11,126 lbs of pollutants removed each year)
  • Stormwater peak flow reductions (8 million gallons per year)
  • Energy savings (915 MWh and 125,476 therms each year)
  • Carbon sequestered and avoided (1,657 tons each year)

Urban forests are important not just for monetary value but for mental and physical health benefits, as well as providing habitat for wildlife.

Emerald Ash Borer Information

Emerald Ash Borer (EAB) is an invasive beetle that was discovered in the U.S. in 2002. Brought in from Asia via wood packing material, it is now found in 36 states and is causing the rapid decline of all ash species.

How to Identify an Ash Tree:

  • Opposite branching pattern, meaning branches are directly across from each other.
  • Diamond-shaped bark (resembles a basketball hoop).
  • Compound leaves with 5-11 leaflets.
  • Ash seeds are paddle-shaped and occur in clusters, remaining on the tree until fall or early winter.

Impacts of Emerald Ash Borer:

The Minnesota Shade Tree Advisory Council found that “the loss of all urban/public ash trees in the state will lead to 1.7 billion gallons of water entering our stormwater systems annually.” To preserve the community forest in South St. Paul, there must be an increase in biodiversity.

Best Management Practices for EAB-Infested Areas

According to the MN Department of Agriculture, best management practices for known EAB-infested areas include:

  • Enacting quarantines on a large scale (county or greater).
  • Limiting tree removal during high-risk periods (May through September).
  • Properly disposing of removed ash trees to prevent further spread.

When to Prune or Remove Ash Trees

  • May through September is flight season for the emerald ash borer beetle, meaning there is a high risk of infection for ash trees.
  • During this time, avoid removing ash trees or branches unless necessary. If removal is required, chip the outer 1" of bark on-site before transport.
  • Emerald Ash Borer beetles are dormant from October through May, making this the best time for pruning and removal.

How to Prevent the Spread of EAB:

  • Do not import materials to MN that could harbor EAB, such as firewood and ash wood.
  • Do not move firewood unless it is MDA-certified.
  • It is illegal to move non-coniferous firewood from EAB quarantine areas into MN.
  • Stay informed about EAB signs and monitor the health of your ash trees.

For more information, visit the U.S. Department of Agriculture.