MNFI Great Lakes island invasive-species action and ecological-resilience framework, 2019

What this adds

MNFI Report 2019-17 supplies the missing regional planning layer for invasive species. It is not a species-observation census; it explains how to combine island boundaries, natural-community and rare-species assets, invasive distributions, vectors, treatment data, and climate-resilience factors into a decision framework.

The project assembled a 1,709-feature baseline island dataset with 440 named islands, reviewed 178 spatial resources and 23 secondary vector resources, compiled 256 references, and defined 93 priority invasive species across 13 taxa. It also created an invasive dataset by reconciling MISIN, NAS, GLANSIS, EDDMapS, MDNR Forest Health, and earlier MNFI project data.

Invasive-distribution baseline

As of March 1, 2019, the report counted invasive species mapped on 206 islands. The number of unique invasive species per island ranged from 0 to 43; 43 islands had at least one Michigan watch-list species, 143 had high aquatic invasive risk, and 164 unique invasive species were mapped across the island dataset.

These values are useful scale indicators, not current Beaver Archipelago counts. The report explicitly warns that most source systems are one-shot snapshots that need to be re-queried, and that some data are unverified, spatially imprecise, or not reported at all.

Beaver and CAKE context

The report’s CAKE CISMA aggregate contains 69 islands and 61 unique invasive species, along with 257 rare element occurrences, 30 rare-animal species, 18 rare-plant species, 19 natural-community types, six heron rookeries, six federally listed species, 14 Great Lakes endemics, and an average of eight fish spawning species. This is a regional CAKE aggregate—not a Beaver Island or Beaver Archipelago total—and the distinction is preserved in the structured index.

For Beaver Island specifically, the report highlights early detection and response as a successful model. It identifies eradication of the only known garlic-mustard occurrence and sustained control of non-native Phragmites as immediate concerns in its 2019 synthesis. The 2024 MNFI guide provides a later Beaver-focused chronology, including the 28-acre Phragmites treatment in 2008, reported 95-percent reduction the following year, maintenance-mode patches, and a confirmed invasive-plant list. Those records should remain temporally and evidentially distinct.

Birds, shoreline vegetation, and vectors

The report connects invasive management to colonial waterbirds: 92 percent of the colonial waterbirds counted in the cited fourth decadal survey were on islands. It recommends documenting non-native Phragmites at marsh-tern and other colonial-waterbird sites, because vegetation change, water levels, cormorant and gull control, land use, invasive species, disease, and oil spills can interact in colony dynamics.

The island-level vector summary counts roads on 45 islands, state trails on 13, ferries on 16, airports on 10, marinas on 21, and shoreline modification on 89. These are regional counts, not risk scores for any individual Beaver Archipelago island. A road, ferry, dock, or airport is a potential pathway—not proof that an invasive species used it.

Soils, geology, forests, and resilience

The report explicitly names island area, configuration, topography, soils, age, and ecological complexity as intrinsic factors affecting invasive and climate resilience. That gives the project a defensible reason to join the invasive records to SSURGO soils, Quaternary geology, hydrology, forest structure, canopy, land cover, and natural-community layers rather than treating invasive species as a standalone list.

Its planning principle is to consider climate resilience and invasive control together: maintain intact natural systems, prevent new introductions, map vectors, use early detection and rapid response, and monitor treatments. This is a framework for selecting comparisons; it does not establish a habitat- suitability score or a climate-impact forecast for Beaver Island.

Limits and next data step

The held report does not contain the underlying individual-island Island Database, digital appendices, or a current treatment GIS layer. It therefore does not justify drawing invasive-occurrence points or assigning CAKE aggregate values to particular islands. The next high-value retrieval is the underlying MISIN/MNFI/EDDMapS project data or authorized treatment layers, especially for Phragmites, garlic mustard, Japanese knotweed, spotted knapweed, and shoreline natural communities.

Added 3 August 2026. Recent changes