• Start-up
  • Planning
  • Action
  • Evaluation
The Adaptive Silviculture for Climate Change (ASCC) Network is a collaborative effort to establish a series of experimental silvicultural trials across different forest ecosystem types. We are currently implementing an affiliate trial within the Mississippi National River and Recreation Area, a national park along the Mississippi River in the Twin Cities Metro Area of Minnesota.

Project Area

Floodplain forest at Crosby Farm Park
The size of Crosby Farm Regional Park, its diversity of life, many recreational opportunities, tranquil settings, and easy access makes this a popular park to escape the bustle of a frenzied city life. Mostly floodplain forest, Crosby Farm is a place to wander its many paths and bike trails to enjoy the river and forests and is a destination for birders, especially during spring and fall migration.
Some key facts:
- 549 acres
- A 10 minute drive from downtown St. Paul
- Largest natural park in the city
- 530,000 visitors annually
Learn more here: https://www.stpaul.gov/facilities/crosby-farm-regional-park

Management Goals

Large room with scientists and managers at a workshop

A team of over thirty floodplain forestry specialists from the region joined researchers and managers for a two-day workshop in March 2019 to develop the study design for the ASCC project site.  The team developed a set of Desired Future Condition statements, Objectives, and Tactics for each major climate adaptation trajectory (resistance, resilience, transition). These three treatments are summarized briefly below:

 

 

Resistance:

  • Maintain closed canopy condition (Average cover of 50-60% due to gap creation and EAB, with subsequent tree recruitment restoring cover to 80%)
  • Promote or enhance native regeneration (natural or planted)
  • Recruit regeneration above deer browse into the canopy
  • Manage to decrease invasive species cover (trees and herbaceous)
  • Maintain all large diameter trees (especially cottonwoods) with large crowns (nest habitat)
  • Maintain vigor of existing desirable trees (green ash may/not be included here)
  • Maintain recreation value and opportunities for multiple use of the area

Resilience:

  • Promote a broad suite of species: native to the Mississippi River Basin that are future-climate adapted including flood-tolerant and drought-tolerant species
  • Promote less common native species
  • Promote trees with vigor and seed potential
  • Low herbivory
  • Provide wildlife trees with big crowns for nesters – provide eagle-nesting habitat
  • Provide cavity trees/snags for wildlife
  • Decrease invasives and prevent new invasives

Transition:

  • Maintain minimum of 50% average canopy cover across the treatment
  • Incorporate future-adapted, flood-tolerant tree species from seed zones farther south along the Mississippi
  • Consider additional species in future years
  • Test southern genotypes of native species (e.g., silver maple, cottonwood, hackberry)
  • Triage approach to invasive species management 
  • Match species to microsite conditions (topography)

Overall:

  • Diverse, stratified canopy
  • Natural regeneration with different age classes
  • Promote canopy closure
  • Diverse habitat for wildlife
  • Migratory flyway
  • Pollinator habitat
  • Diversity for pest resistance
  • Cottonwood regeneration
  • Bluff trail restoration, bluff slope erosion control
  • Continued monitoring and removal of invasive vegetation

    Climate Change Impacts

    For this project, the most important anticipated climate change impacts include:
    Warmer temps, especially night-time in both summer and winter
    Wetter – more heavy rain events, flooding
    More drought stress in summer
    Shift of hardiness zones to 5 or 6 (similar climate to Omaha, NE)
    Extreme events, including polar vortex impacts – extreme low temps in winter
    Invasive species considerations

    Challenges and Opportunities

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

    Challenges

    Tree species currently found in the park are expected to see reduced habitat suitability under climate change, including northern white cedar, black willow, silver maple, cottonwood, and boxelder.
    Ash species are declining due to emerald ash borer and are expected to largely disappear from the forest canopy.

    Opportunities

    Some tree species are expected to have increased habitat suitability under climate change, including bur oak, swamp white oak, hackberry, American elm, and red mulberry.
    Habitat suitability for honeylocust, sycamore, and swamp white oak is also projected to increase (currently found in similar floodplain forests in southern Minnesota and Iowa).

    Adaptation Actions

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

    Area/Topic
    Approach
    Tactics
    Resilience
    Incorporate genotypes of existing species that are adapted to warmer temperatures
    Incorporate a broader range of flood-adapted species native to Minnesota and northern Iowa
    Transition
    Shift the species composition to be more similar to areas in southern Iowa and Missouri
    Incorporate species and genotypes that are expected to gain suitable habitat in the area but are not currently present in Minnesota

    Monitoring

    Baseline data was collected in fall 2019 and plots will be monitored throughout the 20-year project, for example:
    Overstory measurements (overstory are trees greater than 5 in. dbh) (status, species, height, health, etc.)
    Seedlings and Saplings (1 to 4.9 inches dbh) of live trees (species, size class, forest health concerns)
    Herbaceous layer
    Down dead wood
    Soils

    Project Documents

    Next Steps

    Fencing will be installed around plots and trees will be planted in 2020.

    Learn More

    Keywords

    Assisted migration
    Flooding
    Genetic diversity
    Insect pests
    Lowland/ bottomland hardwoods
    Planting
    Research

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