Alvin Creek Headwaters
The Alvin Creek complex presents an excellent opportunity to protect a unique assemblage of high-quality biological communities and glacial landforms. At the heart of the complex are the Alvin Creek headwaters wetlands, a unique area of springs and ponds, bogs and sedge meadows, alder thickets, and lowland forests of various types. Alvin Creek, part of the Brule River watershed, begins as the outlet of a seven-acre spring pond, flows into a small drainage lake, thence between drumlin ridges where the stream is mostly alder-lined and alternately associated with wet forests of black spruce/tamarack, white-cedar, and black ash. The areas surrounding the spring pond and lake are for the most part open and very wet and support a rich and unusual patchwork of bog, sedge meadow, and marsh species that defies formal community classification. Several rare and/or uncommon plant species occur here. The surrounding uplands are forested mainly with hemlock-hardwood mixes, but also include some rich hardwoods and a small but excellent stand of old-growth hemlock under numerous super-canopy white pine. Upland stands on adjacent State Trust lands include minimally disturbed old-growth. Adjacent old-growth stands on National Forest lands are restricted to narrow zones on steep slopes bordering wetlands and are dominated by hemlock. Hemlock up to 30 inches in diameter is common in the best stands, mixed with sugar maple and yellow birch of comparable size. White pine forms a super-canopy in many of the older stands. Understories are generally quite open in the older stands, though sugar maple saplings are dense in a few places. The shrub layer is poorly developed, while the groundlayer varies from dense and diverse to rather sparse and species-poor, depending on soil and stand type. Intermediate wood fern, oak fern, maidenhair fern, lady fern, rosy twisted stalk, club-mosses, Canada mayflower, and American starflower are common groundlayer species. Alvin Creek and its tributary have a history of beaver activity and the most recent flooding, in the 1980's, resulted in the killing of many lowland forest stands, including stands of white-cedar and black ash. As evidenced by the numerous standing dead trees, flooding occurred along nearly the entire length of those portions of the creeks within the complex, including the headwaters spring pond area. The open bog surrounding the spring pond apparently suffered no lasting ill effects, as the rare plant populations are still present. Alvin Creek Headwaters is owned by the US Forest Service and was designated a State Natural Area in 2007.