Ecological dynamics
The state and transition model (STM) consists of three states: Reference State, Tillage State, and the Degraded Woodland State. The model Reference State describes a mature, wet-mesic, mixed hardwood forest. State 2 is the Tillage State which describes land transitioned to agricultural production. This is the most common state in MLRA 103 for this site. A few areas within this State have been reseeded to native warm season or cool-season grasses. State 3 is a Degraded Woodland State in which human disturbances have modified the plant community composition and structure. Invasive species, an absence of a natural fire regime, hydrological alterations, and unmanaged grazing are common triggers transitioning a site to State 3.
This site is largely confined to the eastern and northeastern portion of MLRA 103 where fire has been historically suppressed by topography and density of water bodies. This site is common within the Big Woods ecoregion of Minnesota.
The current dominant land use is corn and soybean production. Areas not in row crop agriculture tend to exist as forested preserves or are in other miscellaneous land uses.
State 1
Reference State
The Wet Clayey Forests Reference State in this model is a mature, wet-mesic, deciduous forest. Common species include sugar maple, black ash, and slippery (red) elm. The shrub components consists of chokecherry plus a variety of tree seedlings and saplings. The understory on high-quality sites is diverse and boast a variety of native herbaceous species.
In absence of large-scale natural or anthropogenic disturbances, this ecological site is relatively stable. Small gap regeneration occurs commonly. Early-successional dominants include basswood and sugar maple. Mid-successional species include sugar maple, ash, basswood, and elm.
Resilience management. Resilience management practices include monitoring for invasive vegetation, applying herbicides as needed, and excluding anthropogenic disturbances such as grazing and logging.
Community 1.1
Reference Community
The Clayey Wet Forests ecological site is characterized by multiple canopy species, a variable shrub layer, and a diverse ground cover of native herbaceous species. Historically, elms were dominant in many areas, but due to the Dutch elm disease, are greatly reduced today. The shrub layer includes chokecherry and hardwood saplings. Natural small-gap disturbances zones transition through successional plant communities. The early-successional community is dominated by basswood and sugar maple. The mid-successional community is often dominated by sugar maple and black ash.
Resilience management. Resilience management practices include monitoring for invasive vegetation, applying weed control methods as needed, and excluding disturbances such as grazing and large-scale timber harvesting.
State 2
Tillage State
The Tillage State contains the Row Crop Community and the Seeded Grassland Community. This state describes areas currently in crop production or areas that were tilled but now are seeded to grass. Pathway mechanisms include preparing the site, planting desired species, applying herbicide, applying fertilizer, and harvesting. Hydrological modifications (tiling and ditching) are commonly installed to improve drainage. Soil tillage is the primary trigger to State 2. Tillage alters dynamic soil properties, including bulk density, structure, organic carbon content, and saturated hydraulic conductivity. Intensive tillage negatively impacts soil ecological functions. Conservation practices help mediate soil health impacts. Conservation tillage minimizes soil disturbance and improves soil structure and soil health. A cover crop rotation builds soil structure, improves infiltration rates, reduces erosion, and protects water quality.
Some areas within this ecological site have been converted to a native warm-season grasses under a NRCS conservation program. Species selection will depend on individual site characteristics including hydrology. Cool-season grasses have been established on some areas. Common species include reed canarygrass, and Kentucky bluegrass. Although seeded grasslands are not biologically diverse, they still offer benefits to wildlife, water quality, and soil health.
Resilience management. Prescribed fire is a resilience management practice on warm-season grasslands.
Seeding, fertilizing, and controlling weeds and brush are resilience management practices for cool-season grasslands.
Community 2.1
Row Crop Community
Community 2.1 consists of intensive row crop agriculture. Soil tillage, ditching/tiling, and intentional plant establishment are the primary triggers. The most common crops are corn and soybeans on an annual rotation. Conservation tillage practices may be implemented to reduce soil erosion while still maintaining a crop rotation. Examples include no-till or ridge-till, which leave residue on the surface of the field. Additional soil health benefits can be gained by adding alternative crops to fields that are already in conservation tillage. By diversifying the crop rotation, landowners take additional management steps to improve soil health and protect water quality.
Resilience management. Resilience management practices include preparing the sites, planting, fertilizing, controlling weeds, and harvesting. The maintenance of the desired vegetation community is controlled by the intensity, frequency, duration, and timing of agricultural practices.
Community 2.2
Seeded Grassland Community
This community has been established with warm-season or cool-season grasses. The primary trigger is the intentional establishment of a grass species. Warm-season grasses are commonly planted in conjunction with a USDA-NRCS conservation program. Numerous native grasses and forbs may be selected depending on site characteristics such as hydrology. Cool-season grass species, such as Kentucky bluegrass and reed canarygrass, are a minor land use. Many of these areas are eventually transitioned to annual crop production.
Resilience management. The resilience management practices may include planting desired species, managing grazing, mowing, fertilizing, and controlling unpalatable plant species.
Prescribed fire is a resilience management practice for warm-season grasslands. The controlled application of fire modifies vegetation structure and influence ecological processes.
Pathway 2.1A
Community 2.1 to 2.2
This pathway converts Community 2.1 (row crops) to Community 2.2 (seeded grassland). The primary mechanism of change is the seeding of desired grass species.
Forage and Biomass Planting |
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Pathway 2.2A
Community 2.2 to 2.1
This pathway describes the site transitioning from a seeded grassland to row crop agriculture. This is a common pathway throughout MLRA 103 sites are placed in crop production.
The mechanisms of change are tillage, drainage, and intentional plant establishment (crop seeding). Resilience management practices include weed control (herbicide application), disturbance management (field cultivating), and harvest management.
State 3
Disturbed Forest State
This state describes a wooded site that has been disturbed and exhibits altered forest species composition. Numerous ruderal woodland and forest plant communities may occur on this ecological site depending on the type and severity of disturbance, the length of disturbance, available seed sources, ongoing disturbances (selective harvest, grazing), and management activities. Common species include sugar maple, black ash, basswood, elm, and hackberry. Various non-native shrubs, grasses, and herbaceous plants are often present.
Community 3.1
Disturbed Forest Community
Community 3.1 is an altered forest community caused by previous or ongoing human disturbances. Invasive species are common in this community. Canopy composition varies depending on the severity and type of disturbances, community age, and the availability of seed sources. Non-native species, such as Kentucky bluegrass and common buckthorn, are often common and will continue to increase without management intervention.
Transition T1A
State 1 to 2
Transition T1A is the conversion of the Reference State to agriculture. The triggers are site clearing, soil tillage. and intentional plant establishment (crop seeding). Resilience management practices include common agricultural practices such as seeding, fertilizing, and managing invasive plants with herbicides or field cultivation. Hydrological modifications, such as ditching and tiling, may be present.
Constraints to recovery. Site clearing and soil tillage preclude recovery of the former state.
Transition T1B
State 1 to 3
Transition T1B is a transition from a mature deciduous forest to a disturbed (ruderal) forest. Triggers include timber harvest, surface site disturbance, grazing, and introduction of non-native species. The native plant community is altered, and these areas do not exhibit the ecological function or vegetative composition of State 1.
Restoration pathway R3A
State 3 to 1
Restoration to the Reference State may be feasible for some sites with long-term management inputs including restoration of natural hydrology, establishment of desired species, forest stand management (selective thinning), and control of invasive species.
Triggers include intentional plant establishment (planting desired species), absence of disturbance (site protected from grazing and other site altering disturbances), timber stand improvement inputs, and eradication of invasive plant species.
Brush Management |
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Tree/Shrub Site Preparation |
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Tree/Shrub Establishment |
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Forest Stand Improvement |
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Transition T3A
State 3 to 2
Transition T3A is the transition of a disturbed forest state to agriculture production. This is a common pathway in MLRA 103.
The mechanisms of change include timber harvest, site preparation, tillage, and intentional plant establishment (crop seeding). Continued resilience management practices are necessary and include weed control (herbicide application), disturbance management (field cultivating), and harvest management.
Constraints to recovery. Soils tillage and the transition to agriculture preclude recovery of the former state.