Floodplain Forest Enhancement-Mississippi River, Phase 3
Audubon successfully completed enhancement projects within a diverse array of floodplain forest habitats. Work was completed on 1260 acres of floodplain forest land, which was very close to our goal of 1290 acres. Through phase three, over 70,000 trees were planted, invasive species were managed, and quality trees were given more space to grow. Our partnerships with the US Fish and Wildlife Service, the US Army Corps of Engineers, and Minnesota DNR greatly increased our ability to produce better habitat through sharing resources, ideas, and best management practices, further expanding our ability to improve bird habitats in the region.
Audubon's floodplain forest enhancement program was designed to help sustain floodplain forest along the Mississippi River and the lower ends of major tributaries. Tree disease and pests have killed the Elm and Ash. Mature silver maple trees are starting to die back due to old age and increased flood frequency and duration. There are not enough young trees in the landscape to replace the maples as they die. These forests provide critical habitat during spring and fall migration and for forest dependent birds. Without active management these forests will continue to decline over time.
This floodplain habitat is under constant pressure from invasive species. Our program is focused on restoring forest and forest health by planting trees and seeds, forest stand improvement, and managing invasive species to support natural forest regeneration. We prepared sites for planting or natural regeneration using herbicide, disking, or mowing. We planted bare root tree seedlings, container trees, cottonwood cuttings, or direct seeded trees including oaks and walnuts. We used tree tubes to protect trees from deer and voles; improved tree vigor and growth through selective thinning; and controlled weeds through herbicide treatments and mowing after planting.
Our geographic scope included the Mississippi River from Hastings to the Iowa border and the lower ends of major tributaries. We also worked in areas near the Mississippi River in SE Minnesota that function as a part of the Mississippi River Flyway including state forests, Wildlife Management Areas, or National Wildlife and Fish Refuge lands.
Our priorities were determined in cooperation with MN Department of Natural Resources, US Fish and Wildlife Service, and US Army Corps of Engineers. All projects were on public lands owned and managed by these agencies. Priorities were based on forest condition and threats, habitat needs, logistics, and access. Our goals were to increase the quality and quantity of forests and our strategies include manage invasive species long enough to establish forest canopy and maintain a diverse forest structure that benefits birds and other wildlife. Our objectives were designed to utilize a variety of enhancement tools, monitor results, and apply that information to designing new projects.
A description (explanation) of each type of treatment we used is provided below.
We used our best science on a natural regeneration treatment (herbicide application and germination inhibitor) to create bare ground conditions to enhance natural seed catch from native species on 376 acres at Root River and Garvin Brook.
Invasive species frequently out compete tree seedlings for resources. Audubon used herbicide to reduce reed canary grass coverage and buckthorn density on 270 acres. Japanese Hops was the target on another 150 acres.
Audubon planted over 64,500 bare root seedlings into existing forested units at Garvin Brook, Horseshoe Bend, Root River, and Whitewater Delta across 226 acres. We planted over 5800 3-gallon container trees at Garvin Brook, Root River, Niebeling, and Vermillion River across 81 acres.
$1,357,000 the first year is to the commissioner of natural resources for an agreement with the National Audubon Society to restore and enhance floodplain forest habitat for wildlife on public lands along the Mississippi River. A list of restorations and enhancements must be provided as part of the required accomplishment plan.
Floodplain forests are rare habitats compared to adjacent upland forests, often found in relatively narrow ribbons along river corridors and historically providing important travel routes for wildlife. The Mississippi River, a critical migration corridor for birds, provides some of the most significant tracts of floodplain forest in the United States. In Minnesota, the Mississippi River and lower ends of tributaries include large areas of high biodiversity significance as identified by the Minnesota County Biological Survey and the Minnesota Wildlife Action Network.
Studies by the US Geological Survey along the Upper Mississippi River have shown more species of songbirds use these floodplain forests than adjacent upland forests. Species of special concern, including Cerulean Warbler and Red-shouldered Hawk, require large contiguous habitat blocks of floodplain forest for survival. The forests we enhanced should serve as habitat for those species in the future. Audubon has completed breeding season bird surveys in floodplain forests and other Minnesota species of greatest conservation need that are found in high concentrations include Eastern Wood-pewee, Bald Eagle, Prothonotary Warbler, Yellow-bellied Sapsucker in addition to the more than 20 species that use the forest for migratory stopover sites. Work performed by this grant will help ensure the long-term sustainability of these valuable floodplain forests along the Mississippi River.
The desired future condition that we target is large tracks of mature forest. While our target species are Cerulean Warblers and Red-shouldered Hawks, this habitat type is also important for the federally endangered Northern Long-eared Bat (Myotis septentrionalis) and Tricolored Bat (Perimyotis subflavus). Both species were listed in 2022 and the documents describing the decision mention the loss of mature deciduous hardwood forest, their preferred habitat, as an important factor negatively affecting the viability of their populations.
Private Foundation, USFWS, Private Foundation and N/A