Beaver Island biodiversity appendices and island distribution records, 2017–2024

Summary

This index makes two complementary modern biodiversity sources searchable at the record level. The 2024 Michigan Natural Features Inventory landowner guide is Beaver-Island-specific and supplies habitat vocabulary, natural-community ranks, rare plants and animals, a non-exhaustive native-plant appendix, invasive plants confirmed as of 2023, and a seasonal bird-list extract. The 2017 Michigan Department of Natural Resources plan places Beaver, Garden, High, Hog, North Fox, South Fox, and Whiskey islands in one state-land management frame and adds island-marked amphibian, reptile, and rare-species tables.

The resulting index contains 304 records across eight source-defined categories:

Vegetation and habitat structure

The MNFI community appendix names bog, boreal forest, dry-mesic and mesic northern forest, emergent and submergent marsh, hardwood-conifer swamp, interdunal wetland, limestone cobble shore, open dunes, poor conifer swamp, poor fen, rich conifer swamp, and sand-and-gravel beach. These names connect the forest, wetland, shoreline, dune, and geology themes without collapsing distinct natural communities into one generic “island habitat” category.

The 158 native-plant rows include 16 explicitly labeled trees: balsam fir, black spruce, hemlock, northern white cedar, red pine, tamarack, white pine, white spruce, American beech, balsam poplar, basswood, ironwood, red oak, sugar maple, white ash, and yellow birch. The same appendix also records grasses, sedges, shrubs, ferns, clubmoss, moss, and many wetland, dune, shore, and forest wildflowers. The periods are typical flowering, fruiting, cone, spore, or vegetative periods as reported by the guide—not observations from a single field season.

The guide separately lists 31 invasive plants confirmed on Beaver Island as of 2023, including Phragmites, Japanese knotweed, garlic mustard, purple loosestrife, Japanese barberry, multiflora rose, and Oriental bittersweet. The index keeps these as a dated source list; it does not infer present abundance, spread, or parcel-level presence.

Animals, birds, and island connectivity

The guide’s animal extract records bobolink, dickcissel, eastern meadowlark, eastern bluebird, grasshopper sparrow, horned lark, Lapland longspur, piping plover, savanna sparrow, and upland sandpiper, alongside emerald ash borer as an invasive pest. It preserves the source’s seasonal observation codes and breeding indicators rather than converting them into a complete bird checklist.

The MDNR Appendix A table records 22 amphibian and reptile species across the seven-island frame. The Appendix B table records 38 rare-species rows. Counting the source’s table marks gives the following record associations (one species can appear on several islands):

These counts are connectivity aids, not abundance estimates. The plan says its records cover all lands surveyed regardless of ownership, and that the rare species list was compiled through Spring 2015. The table marks establish an island association in the source, not a precise locality, population size, ownership, public access, or present-day occurrence.

Evidence limits and taxonomy

The two sources operate at different scales and dates. MNFI’s guide is a landowner-facing Beaver Island guide; its native-plant list explicitly is not exhaustive. MDNR’s plan is a state-land management document whose appendices compile records from broader surveys and do not constitute a complete survey of private lands or the whole archipelago. Status labels are retained as reported and are not silently refreshed to current legal classifications.

Names are preserved as printed in each source. The index does not merge historical and modern taxonomies, turn a common name into a new occurrence claim, or expose sensitive rare-species locations. Those limitations make the index suitable for cross-source research, habitat questions, and future mapping without overstating what the tables prove.

Added 2 August 2026 · revised 3 August 2026. Recent changes