A study and comparison of the habitats of Equisetum arvense and Equisetum sylvaticum in northern Michigan and along the north shore of Lake Superior.

Abstract

The aim of this project is to compare and contrast two species of the Equisetaceae family, their morphologies, their habitats, and their associational interactions. Equisetum arvense, the common, or field horsetail, and Equisetum sylvaticum, the woodland horsetail, are both species native to Michigan. ... Based on the information I gleaned from my field observations, I have drawn the following conclusions concerning the habitats of Equisetum arvense and Equisetum sylvaticum: (1) Equisetum sylvaticum is a circumboreal species preferring cooler northern climates. It has a narrow range of tolerance for soil moisture, preferring soil that has a consistant water supply but that is not subject to complete saturation or standing water. (2) Equisetum arvense is commoner in northern Michigan than is Equisetum sylvaticum. It has a fairly broad range of tolerance for soil moisture, light levels, and soil types. (3) Both species of Equisetum appear frequently in association with Thuja occidentalis in northern Michigan, indicating a preference for an alkaline environment. (4) Both species of Equisetum appear to be encouraged in areas of habitat disturbance; along trials, at forest edges, along eroded stream banks, along roadsides.