The Ecology of the "Copper Moss" Mielichhoferia mielichhoferi in Colorado

Mielichhoferia mielichhoferi (Hook.) Wijk &l Marg. is reported from the San Juan Mountains of southwestern Colorado. Acid conditions and high concentrations of and sulfate are present in its substrate. The two species of Mielichhoferia in North America are considered to be copper mosses because of their supposed association with metallic minerals. Gams and Morton (1925) reported the predilection of M. mielichhoferi for ore, especially pyrite, and for iron and aluminum-rich silicate rocks. Schatz (1955) referred to the restriction of copper mosses to sulfur springs and sulfide ores, especially and iron. In the region of Mt. LeConte in Tennessee M. mielichhoferi was found on limonite and slaty and argillaceous rock rich in carbon and sulfides, especially iron pyrite (Schofield, 1959). The sandstone cliffs along the south shore of Lake Superior at Pictured Rocks, Michigan, was cited as the habitat of M. mielichhoferi in the first reported occurrence of the species in North America (Nichols, 1933). The Thunder Bay District, Ontario, locality of M. mielichhoferi reported by Crum (1956) was a shale cliff. From the above list it might seem that M. mielichhoferi occurs on a wide range of substrates and that the reported restriction of this species to metallic minerals is contradictory. The substrate preferences of M. mielichhoferi should be determined on the basis of actual substrate analyses. The one such analysis made previously in this country was by Shacklette (1967). Bryologists interested in the geochemical aspects of the genus Mielichhoferia have emphasized the need of additional substrate analyses in order to establish the ecological relationship of these mosses. The reported distribution of M. mielichhoferi in the United States includes restricted mountainous localities in Maine, New York, Tennessee, Michigan, Colorado, California, Alaska, and Hawaii. In addition, specimens from North Carolina are in Duke Herbarium (L. E. Anderson, personal communication).