Michigan Invasive Species Model

Michigan Natural Features Inventory (MNFI) and the Department of Natural Resources (MIDNR) Wildlife Division have been collaborating since 2019 to develop an invasive species treatment prioritization model of state lands.

This modeling work addresses MNFI’s mission to guide the conservation of Michigan’s biodiversity for current and future generations by providing the highest quality scientific expertise and information and the DNR Wildlife Division’s complementary mission to enhance, restore and conserve the State’s wildlife resources, natural communities, and ecosystems for the benefit of Michigan’s citizens, visitors, and future generations.

MNFI has also collaborated with the Michigan Department of Military and Veterans Affairs, and the Saginaw Chippewa Indian Tribe to expand the modeling effort beyond DNR managed lands to the Fort Custer Training Center and to the Saginaw Chippewa Indian Reservation.

The objective of this project is to develop a tool to prioritize invasive species management in Michigan using data collected through the Michigan Forest Inventory (MiFI). Including an array of spatial variables, we used a modeling technique called GIS-Based Multicriteria Decision Analysis to prioritize invasive species treatment across all stands within the MiFI database.

This approach allows you to select multiple input variables on different units of measure; reclassify them to a common value scale; apply weights to each variable; sum scores; and generate a weighted geographic overlay and invasive species treatment priority score.

Vegetative cover of state lands in Michigan is tracked in the Michigan Forest Inventory (MiFI) database. Stands within the MiFI database are polygons that represent relatively homogeneous areas of a similar cover type across the landscape. Stand data includes canopy closure, stand age, upland/lowland classification, and percent cover by strata.

Through aerial photographic interpretation and ground-truthing, by 2022, wall-to-wall land cover mapping generated more than 181,021 stands across Michigan, constituting 1,829,062 hectares (4,519,714 ac) with a mean stand size of 10 hectares (25 ac).

The MiFI database is dynamic and is continually updated as additional stands are mapped, surveyed and managed. These stands are classified to a cover type class (e.g., "Mixed Oak" and "Lowland Deciduous Forest") and attributed with vegetative data by strata (i.e., canopy, subcanopy, understory, and ground cover composition), canopy closure, percent cover by canopy species, and stand age.

A fundamental assumption of our model is that stands that are threatened by invasive infestation should be prioritized for treatment when they have a high value of any combination of the following characteristics:

The four characteristics were used as our 'factors', or categories, in which we assigned multiple model variables to determine prioritization. For each stand, the variables were evaluated, scored and weighted to generate an overall priority score.

The Invasive Species Treatment Prioritization Model can be used to aid in decision-making for invasive plant species management. The model was developed to foster informed discussion and facilitate difficult decisions about allocation of finite resources.

The use of stands as the building blocks of the model allows resource managers to evaluate invasive species treatment priorities at multiple scales across state lands. The model can be used to inform both site-based management decisions and landscape-level planning.

The model is accessible to natural resource managers graphically in GIS and also through the stand-level files that are attributed with the total invasive species treatment prioritization score as well as the individual scores for each of the input variables. In addition, the model outputs are publicly accessible through an online Web Map. Users can zoom into areas of interest and see the invasive priority score by stand and click on each stand to also view scoring for each of the input variables.

We express our sincere gratitude to the numerous Department of Natural Resources (DNR) staff that helped administer and guide our modeling especially Michael Donovan, Greg Norwood, and Amy Derosier. This effort was informed by our concurrent project to model the ecological need for prescribed fire. We are thankful for the fruitful interactions with numerous DNR staff, especially Mark Sargent, Christopher Hoving, Michael Donovan, Glenn Palmgren, Robert Clancey, and Ray Fahlsing who all guided the modeling project. In addition, we thank Michigan Department of Military and Veterans Affairs (DMVA) staff Michele Richards and Brian Huggett who supported an invasive prioritization model for Fort Custer Training Center. We thank Anthony Koop with the U.S. Department of Agriculture (USDA) for facilitating our use of the Weed Risk Assessment (WRA) tool. We appreciate the collaborative efforts of the Midwest Invasive Species Information Network (MISIN), especially Claire Peterson. Photographs were generously provided by Matthew Lewis (Michigan Aerospace Corporation), Jesse Lincoln (MNFI), and Aaron Kortenhoven (MNFI). For their support and assistance throughout this project, we thank our Michigan Natural Features Inventory (MNFI) colleagues, especially Jesse Lincoln, Aaron Kortenhoven, Phyllis Higman, Rachel Hackett, Michael Monfils, Rebecca Rogers, Nicole Smith, Kraig Korroch, Ashley Adkins, and Brian Klatt.