A comparison of habitats and microsites of Drosera intermedia and D. rotundifolia (Droseraceae) in northern Michigan, USA and on Lake Superior rock outcrops, Ontario, Canada.

Abstract

Sundews, like other temperate carnivorous taxa, are found in nutrient poor soils. Carnivory has long been thought to provide supplemental nitrogen, phosphorous, and salts to plants growing on poor sandy soils and Sphagnum mats. This project was designed to compare habitats and microsites of two circumboreal sundews, Drosera intermedia and D. rotundifolia, in northern Michigan, USA and southern Ontario, Canada. My goal was to determine why Drosera intermedia and D. rotundifolia are often, though not always, found growing in close association. Specifically, I addressed the following questions: (1) What are the characteristics of habitats common to both sundews? (2) Which sundew species has a more limited distribution among habitats? (3) Are the two sundews limited different microsites within the same habitat?