THE DISTRIBUTION, ECOLOGY, AND CONSERVATION STATUS OF RUBUS ACAULIS MICHX. (DWARF OR ARCTIC RASPBERRY) IN MICHIGAN

摘要

Rubus acaulis Michx. (dwarf or arctic raspberry) is a dwarf herbaceous perennial plant in the rose family (Rosaceae) characteristic of mesic to hydric open and forested habitats across boreal North America. The species ranges south locally to the conterminous United States, where it is designated a sensitive species by the United States Forest Service in Region 2 in Colorado and parts of Regions 6 and 9 in Washington and Michigan, respectively. Rubus acaulis was first discovered in Michigan in 1976,and several additional populations have been documented over the past decade from minerotrophic peatlands in eastern Upper Michigan, extending west to Marquette County. In these habitats, which are classified as patterned fen, northern fen, and poor fen,R. acaulis occurs with a consistent group of vascular plant associates, and is typically most frequent on the tops, sides, and margins of Sphagnum-dominated hummocks. Despite the recent documentation of several very large populations, the long-term prospects for the persistence of R. acaulis in Michigan remain uncertain due to the threat of climate change and associated disruption of ecosystem processes in its peatland habitats.