An Evaluation of ECOSYSTEM RESTORATION OPTIONS FOR THE LOWER ROOT RIVER FLOODPLAIN, MINNESOTA 1844 Prepared for Mickey E. Heitmeyer The Nature Conservancy, Southeast Minnesota Office Greenbrier Wetland Services and U.S. Fish and Wildlife Service Publication No. 11-04 Upper Mississippi River National Wildlife and Fish Refuge September 2011 1 AN EVALUATION OF ECOSYSTEM RESTORATION OPTIONS FOR THE LOWER ROOT RIVER FLOODPLAIN, MINNESOTA Prepared FOR: THE NATURE CONSERVANCY SOUTHEAST MINNESOTA OFFICE PRESTON, MN 55965 AND U.S. FISH AND WILDLIFE SERVICE UPPER MISSISSIPPI RIVER NATIONAL WILDLIFE AND FISH REFUGE LA CROSSE DISTRICT LA CROSSE, WI 54601 BY: MICKEY E. HEITMEYER GREENBRIER WETLAND SERVICES ADVANCE, MO 63730 Greenbrier Wetland Services Report 11-04 SEPTEMBER 2011 Mickey E. Heitmeyer, PhD Greenbrier Wetland Services Route 2, Box 2735 Advance, MO 63730 www.GreenbrierWetland.com Publication No. 11-04 Suggested citation: Heitmeyer, M. E. 2011. An Evaluation of Ecosys- tem Restoration Options for The Lower Root River Floodplain, Missesota. Prepared for The Nature Conservancy Southest Minnesota Office, Preston, Mn. 55965 and U.S. Fish and Wildlife Services, Upper Mississippi River National Wildlife and Fish Resuge, LaCrosse District, LaCrosse, WI. Green- brier Wetland Services Report 11-04. Blue Heron Conservation Design and Printing LLC, Bloomfield, MO. Photo credits: Cary Aloia (http://gardnersgallery.com/), Karen Kyle, Frank Nelson, USFWS, and Sue Fletcher of Friends of Upper Mississippi River NWR This publication printed on recycled paper by ii Contents EXECUTIVE SUMMARY ..................................................................................... v INTRODUCTION ............................................................................................... 1 THE HISTORICAL LOWER ROOT RIVER ECOSYSTEM ............................................................... 3 Geomorphology ........................................................................................... 3 Soils ......................................................................................................... 4 Topography/Elevation .................................................................................. 4 Climate and Hydrology ................................................................................ 4 Historical Vegetation Communities .............................................................. 5 CHANGES TO THE LOWER ROOT RIVER FLOODPLAIN FROM THE PRESETTLEMENT CONDITION .................... 9 General Regional Landscape Changes .......................................................... 9 Specific Changes in the LRR ...................................................................... 11 RESTORATION AND MANAGEMENT OPTIONS ...................................... 15 Determining Appropriate Locations to Restore Specific Natural Community Types ................................................ 15 Restoration of Topography and Hydrology ................................................. 17 Increase Programs to Improve Water, Sediment, and Land Management in Strategic Locations Throughout the Root River Basin ............................................................... 19 MONTORING AND EVALUATION NEEDS ................................................. 23 Sediment Reduction and Control ............................................................... 23 Effectiveness of Restoring Water Flow Pathways, Patterns, and Seasonal Water Regimes ........................................ 24 Long Term Changes in Vegetation and Animal Communities Related to Flooding and Elevation ....................................... 24 ACKNOWLEDGEMENTS ................................................................................ 27 LITERATURE CITED ........................................................................................ 29 iii Karen Kyle iv EXECUTIVE SUMMARY This report provides a hydrogeomorphic (HGM) evaluation of ecosystem restoration options for the 4,800-acre Lower Root River (LRR) floodplain in southeastern Minnesota. The HGM methodology obtains and analyzes historical and current infor- mation about geomorphology, soils, topography, hydrology, and plant and animal communities to: 1. Determine the historical condition and ecological processes of the LRR floodplain. 2. Identify contemporary changes to the physical condition, ecological processes, and biota in the LRR from historical condition. 3. Identify options and approaches to restore and management specific communities and ecological processes in the LRR. An important part of the HGM evaluation is developing a matrix of understanding about the relationships between abiotic landscape features (i.e., geomorphic surface, soils, hydrology) and historical vegetation communities. Major Presettlement communities in the LRR included: 1) open water- aquatic, 2) persistent emergent wetland, 3) shrub/scrub (S/S), 4) seasonal herbaceous wetland, 5) wet prairie/meadow, 6) floodplain forest, 7) riverfront forest, and 8) slope forest habitats. Open water-aquatic habitats were present in river channels and sloughs with nearly permanent water regimes. Deeper floodplain depressions with semipermanent water regimes contained bands of persistent emergent and S/S commu- nities. Backswamp floodplain depressions with seasonal water regimes contained seasonal herbaceous “marsh” type veg- etation that included many perennial and annual “moist-soil” species. Large expanses of floodplains with silty clay loam soils deposited vertically by past flood events supported wet prairie/ v meadow habitats. Higher elevations in the floodplain with vertically accreted silt clay loams and short duration flooding supported diverse floodplain forests. These forests often were on relict or recent natural levees and floodplain terraces. Oaks in these floodplain forests usually are restricted to sites with > 5-year flood frequency and silt clay soils. High elevation in floodplains on point bars and along current and historical channels of the Root River and its main tributaries with sand soils supported riverfront forests containing early succession tree species such as willow, cottonwood, silver maple, river birch, and some hackberry. The edges of the LRR floodplain that transitions into inclining upland slopes historically contained hardwood slope forest communities. A map of the location and distribution of potential his- torical vegetation communities in the LRR was produced in this report. This map identifies the unique heterogeneity of the LRR and reflects the past meandering and soil deposition patterns of the historic Root River. Many regional and site-specific changes have occurred in the LRR from the Presettlement condition. Major changes include alterations in land form and topography, hydrological Frank Nelson regimes and flood water flow paths and extents, clearing of floodplain habitats for agricultural and other purposes, and introduction of invasive plant and animal species. Despite considerable alterations to the LLR ecosystem, many potential opportunities exist to restore former communities and eco- logical processes. This report does not identify specific land tracts or locations for future restoration of historical vegetation com- munities, but it does provide guidance on system-wide HGM attributes that are needed for successful restoration of specific community types. First, the HGM matrix and map of potential historical vegetation communities identifies locations in the LRR that are most appropriate to restore specific community types including those types that are greatly reduced in area and distribution (e.g., floodplain forest with an oak component), represent a “gap” in coverage or connectivity (e.g., riverfront forest corridors along river corridors), or are needed for miti- gation (e.g., wet prairie/meadow). Second, the HGM matrix helps understand what community restoration is appropriate vi if a specific land tract becomes available (or is already under some conservation protection). Here, the HGM information can help decide what habitat type can/should be restored on the site given budget, management, development, and system alteration constraints. In addition to providing guidance on determining appro- priate locations for restoration of specific communities in the LRR, the report recommends actions to: 1) restore topography and hydrology; 2) implement programs to improve water, sediment, and land management in strategic location throughout the Root River Basin; and 3) monitor ecosystem attributes and future management/restoration actions. Specific restoration actions should include programs that: • Protect and reconnect water flow corridors where possible. • Expand floodways and drainage corridors. • Remove obstructions to sheetwater flow through, and drainage of, the LRR. • Implement soil retention practices in strategic areas and sites that contribute the most sediment and surface water runoff. • Restore natural drainage channels, water flow pathways, channel stabilization, and flood distribution areas. • Restore native communities, especially those types that have been most destroyed and/or fragmented. Frank Nelson vii Cary Aloia viii INTRODUCTION The Lower Root River region (LRR) of southeastern Minnesota contains about 4,800 acres of floodplain lands where the Root River enters the broad Mississippi River alluvial valley (Fig. 1). The Root River originates in the Rochester Plateau of southern Minnesota and slowly descends through bluff lands to its confluence with the Mississippi River.