Mosses as Paleoecological Indicators of Lateglacial Terrestrial Environments: Some North American Studies

Miller, Norton

Radiocarbon dated assemblages of mosses from late Pleistocene deposits in Wisconsin (11,850 yBP), New York State (12,100 yBP), and Vermont (11,500 yBP) consist mostly of calcicolous species and include aquatics, mesophytes, and xerophytes. Pollen analyses establish the lateglacial woodland or more open physiognomic settings of the assemblages, and macrofossils of mosses provide details about smaller scale habitats and communities. Lowland rich fens (pH 5.8 or higher, calcium at least 0.9 me/l), base-rich seeps and stream margins, and upland areas of dry, mineral soil are indicated. Species of acidic substrata are poorly represented. Mosses of the short turf growth-form dominate the assemblages in terms of species richness, and from this it can be inferred that open conditions and dry, possibly continental, climates prevailed. Assemblage composition and growth-form spectra are similar to those in boreal white spruce stands of western interior North America. The characterization of paleoenvironments provides a way to postulate former distribution patterns which may prove to be evolutionarily and taxonomically important. The fossil mosses imply that calcareous sites and calcicoles were prominent on the lateglacial landscape. Such plants are now rare in the Great Lakes-New England area where they are restricted to sites in which competition with more abundant species of the surrounding forest flora is minimal.

Mosses as Paleoecological Indicators of Lateglacial Terrestrial Environments: Some North American Studies

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