Floodplain and Upland Forest Enhancement - Mississippi River, Phase 5

The forests of Southeast Minnesota are experiencing a shift in species cover and composition. Floodplain forests are shifting away from native tree cover and towards invasive grass. Oak-dominated upland forests are slowly converting to shade-tolerant maple and invasive species. While forests are never stagnant, these forests require intervention to ensure they remain a healthy and sustainable resource for the state of Minnesota.

The Mississippi River from Hastings, Minnesota to the Iowa border contains some of the largest and most significant tracts of floodplain and river bluff forest north of Saint Louis. These forests and mixed wetlands cover thousands of acres and are especially critical to many species of birds and other wildlife, including Wood Ducks, Bald Eagles, and multiple songbird species of conservation concern which use these areas for nesting and feeding. The upland forest adjacent to the Mississippi River and its tributaries provide excellent wildlife habitat and support the greater river corridor migratory pathway. Special concern species such as the Cerulean Warbler are well known to use both floodplain forest and upland forest, even preferring habitats where they have access to both.

While historically diverse in the number, age, and size of tree species, much of the floodplain forest now consists of silver maple aged 50-70+ years old. These trees are expected to live another 50-70 years, after which they will die naturally. Unfortunately, when trees are lost, reed canary grass and other invasive species move in and prevent natural regeneration. This is occurring at a number of locations within the project area, and without aggressive, long-term management these floodplain forests will be greatly reduced or in some cases disappear completely. Adjacent upland forests are beginning to shift away from their historical oak dominance and are becoming infested with invasive species. A lack of fire and increased maple dominance threatens their value as wildlife habitat. Without management, both forest communities will continue to decline along with their ability to support wildlife.

Project locations and habitats were selected based on state-level Conservation Focus Areas and the Systemic Forest Stewardship Plan. Project work will include selectively controlling invasive plants like reed canary grass and buckthorn across the habitat gradient. Forest stand improvements will be used to improve wildlife tree structure. Site preparations will create the appropriate conditions for natural and artificial tree regeneration. Trees will be planted underneath existing forest canopies and in open areas where forests previously existed. Understory treatments like mowing and fire will be used to control unwanted vegetation and release desirable trees. As a result of this management, floodplain forest habitat will expand while the adjacent upland forests will offer higher quality habitat to wildlife.

Sites were collaboratively identified with MN DNR, U.S. Fish and Wildlife Service, and the U.S. Army Corps of Engineers. Projects will be accomplished using a variety of contractors, Conservation Corps Minnesota Crews, and in-house labor. In total 3,130 acres will be enhanced.