• Start-up
  • Planning
  • Action
  • Evaluation

At Milwaukee's newly redeveloped Turtle Park, the River Revitalization Foundation and a dedicated stewardship team made up of volunteers, college service learners, and summer interns aim to address invasive species while enhancing soil, biodiversity, and habitat for the influx of wildlife to this urban natural area.

Turtle Park, a ~4 acre urban natural area in Milwaukee known for birding, a canoe/kayak landing, a short ADA trail-loop, and access to the Beerline Loop trails, is located at a bend in the Milwaukee River. The property was acquired in 2009, including 2.8 acres for $1.4 million with WDNR stewardship funds, Milwaukee Metropolitan Sewerage District’s Greenseams, and additional support from foundations, corporate, and individual donations. In 2010, the abandoned building on the property was demolished and parking lots removed in 2010 to transform the site into lively wildlife habitat. This urban natural area now attracts wildlife such as red-tailed and cooper’s hawks, tree swallows, migratory birds and waterfowl, coyote, chickadees, soft shell, northern leopard frogs, and butler and common garter snakes. Stewardship remains a critical component of Turtle Park and the primary aim of this project is to revitalize the area by increasing biodiversity and native species, enhancing soil and habitat quality, and reducing and controlling invasive species.

Project Area

Milwaukee's Turtle Park began redevelopment in 2010 and is now a lively urban natural area following the completion of extensive shoreline and habitat restoration. The area attracts various wildlife as well as urban nature enthusiasts such as hikers, birders, anglers, yogis, and paddlers. Two areas of interest in Turtle Park include grassland and lowland forest/shrub car. The grassland community experiences invasive species and urban runoff and sediment and nutrient loading. The shrub car community helps improve water quality by filtering stormwater runoff. It was formerly underwater prior to the removal of a dam below stream, and is still within the floodplain currently dominated by reed canary grass in the understory. The River Revitalization Foundation is currently working to create habitat amenities, remove invasive species, and establish a resilient savanna plant community, which promotes habitat for many wildlife species.

Management Goals

Management Goal 1 (Grasslands): Control invasive species


  1. Reduce invasive species by 80% (7-10 years).



Management Goal 2 (Grasslands): Increase biodiversity


  1. Increase native plant biodiversity by 80%; Introduce 10-20% conservative species (7-10 years).



Management Goal 3 (Grasslands): Enhance habitat quality


  1. Increase plant species beneficial to top 5 migratory bird species observed on site (5-7 years).
  2. Establish more nesting opportunities for turtle species (5-7 years).
  3. Attract more nesting bird species (5-7 years).




Management Goal 4 (Grasslands): Enhance soil


  1. Mitigate against soil depletion and add nutrients. Potential for hydro-fertilizing. (10 years)



Management Goal 5 (Lowland Forest/Shrub Car): Reduce density of invasive species populations


  1. Reduce invasive species by 80% (10-15 years).



Management Goal 6 (Lowland Forest/Shrub Car): Increase native species density in ground layer


  1. Increase native plant biodiversity by 80%; Introduce 10-20% conservative species (7-10 years).

Climate Change Impacts

For this project, the significant, anticipated climate change impacts include:
Temperatures in the Midwest are projected to increase by 5.6 to 9.5 degrees Fahrenheit by the end of the century (2071-2100).
The frequency and intensity of heat waves is expected to increase across the Midwest by the middle of the century (2036-2065).
The frequency and intensity of cold waves is expected to decrease across the Midwest by the middle of the century (2036-2065).
Drought risk is expected to increase across the Midwest by the end of the century.
Average annual precipitation is projected to increase slightly across the Midwest over the next century.
The annual frost-free season is expected to increase by roughly 30 days in the Midwest by the end of the century.
Climate change will amplify many existing stressors to forest ecosystems in the Midwest, such as invasive species, insect pests and pathogens, and disturbance regimes.
Boreal and northern tree species in the Midwest are generally expected to decline in suitable habitat under climate change, while temperate tree species, grasslands, savannas, and woodlands may expand by the end of the century.
Low-diversity systems are at greater risk from climate change.
Species in fragmented landscapes will have less opportunity to migrate in response to climate change.
Forest composition will change across the landscape.
Tree regeneration and recruitment will change.
Native grasslands are fire-dependent natural communities. Climate change projections suggest that burn day options may shift to earlier in the spring or to other seasons.
Non-native invasive plants may increase in productivity and may invade into new areas.
Climate change may increase the frequency and intensity of storm events, causing flooding and runoff of nutrients from agricultural fields and lawns, sediment from fields and streambanks, and salt from roads and sidewalks.
Mesic Prairie is highly vulnerable to climate change. Maintained by periodic fire, this system may have less capacity to adapt to climate change due to their extreme rarity and small and isolated nature that limit options to rearrange and migrate.
Shifting habitat suitability of specific species.

Challenges and Opportunities

Climate change will present challenges and opportunities for accomplishing the management objectives of this project, including:


As we continue to focus on current invasive species on the site and make head-way in reducing the populations our capacity to focus on them may shift as other invasive species found in south migrate into our habitat.
Our site is downstream of the greater 800-acre Mke River Greenway that Turtle Park is a part of. Increased precipitation and major storms could lead to increased flooding, depositing even more (and new) weed seeds.
Although most of the site if upland, limiting weed seed being carried from upstream, Turtle park is very urban with many off-leash dogs that could increase the spread to upland areas.
Thriving species may move out of range, leaving gap for invasive species to populate.
We might see a slight decrease in established native populations as they might not be able to withstand more drought conditions and/or flooding.
Planting the species will be easy. The uncertainty lies in whether the plant species phenology will align with what the migratory species need, when they need them.
Shifting lake levels may affect the ability to establish more nesting opportunities for turtles.
Our emergent aquatic shelf has become completely submerged only 6 years after construction.
Prescribed burning timeframes may be more limited, which is a great tool for adding nutrients.
The reed canary grass population is so widespread, which may make it difficult to increase native plant biodiversity.


We are at and advantage in being able to have a rapid response effort to address new invaders, unlike previously where the land was unmanaged for years enabling invasive species to populate and dominant our green spaces.
Despite the potential for increased flooding, only 1,500 linear feet of shoreline might be directly impacted by weed seed being deposited downstream, most of the site is upland.
Additional southern prairie species will move in range.
Shifts in suitable habitat ranges increases opportunity for assisted migration allowing for more adaptable species diversity.
Mismatched phenology.
The invasive reed canary grass is so dominant in this area that it might not offer a window for new invaders to compete.

Adaptation Actions

Project participants used the Adaptation Workbook to develop several adaptation actions for this project, including:

Sustain or Restore Fundamental Ecological Functions
Remove invasive species that have negative impacts on soil processes or undesirable feedbacks to nutrient inputs. Includes garlic mustard, birds foot trefoil, crown vetch and other invasive nitrogen-fixing legumes; and buckthorn.
Use prescribed fire to maintain fire-adapted ecosystem-prairie/savannah. Time Rx burns to address specific invasive species targets.
Reforest a diversity of tree and plant species to stabilize the soil.
Increase diversity to protect against future pest and pathogen desolation.
Decrease existing RCG invasive populations.
Provide habitat and connectivity for wildlife.
Restore protected riparian areas adjacent to developed areas in order to reduce erosion and nutrient loading into Milwaukee River.
Maintain/Enhance Species and Structural Diversity
Continue planting and seeding desired native grassland species to increase diversity of site and in the seed bank. Plant species with diverse timing of phenological events.
Retain snags and downed trees whenever possible (i.e., those that pose no threat to people or infrastructure).
Maintain/Enhance Genetic Diversity
Climate change projections reflect that hardiness zones will shift from zone 5/6- zone 7/8 and begin incorporating species dominant in regions with those hardiness zones now.
Purchase seed and nursery stock of climate change species from them and/or species currently native to both, but sourcing from that region will increase adaptability of individual species.
Source and/or collect seeds, and plants from a variety of areas, sites to increase overall genetic diversity.
Collect and plant seeds from individuals that are known to thrive in disturbed areas as these individuals may have resistant genotypes Using species that will be better suited for hotter and drier climates.
Begin incorporating cultivar elms in reforested low-land floodplain area.
Reduce Impact of Biological Stressors
Mitigate against another EAB/ash tree decline scenario by promoting tree genus, species, and age classes.
Respond rapidly with stewards and volunteers to limit the spread of invasive species upon introduction.


Project participants identified several monitoring items that could help inform future management, including:
Conduct meandering vegetation survey following USFW survey protocol and/or RRF's FLRI protocol; repeat every 5 years.
Conduct bird walks minimum once/month and weekly during migration periods to accompany eBird observations and annual sightings of emphasis species.
Monitor nest boxes weekly during nesting season and follow nest box monitoring SOPs with goal of successful fledging broods in each box each nesting season.
Contract soil assessments every 5 years until criteria of healthy soil is met (compaction levels between 10-200 PSI; 5% organic cover; Increased nitrogen, phosphorous and potassium levels; Infiltration rate lower than 3.54cm/hour).

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