The submersed macrophyte communities of adirondack lakes (New York,U.S.A.) of varying degrees of acidity

The submersed macrophyte communities of nine high-altitude oligotrophic lakes in the Adirondack Mountain region of upstate New York were characterized in detail in terms of percent cover of each species. The pH of these clear-water lakes ranged from 6.9 to 4.4 and the acid neutralizing capacity ranged from 91 μeq 1^?1 to ?38 μeq l^?1. The degree of acidity covaried with lower total ion content and nutrient status. The dominant species in the circumneutral lakes and in the acidic lakes were the same, with several Utricularia species being the major component of the bottom cover. Species richness and diversity were lower in the acidic lakes (pH < 5.5). The plants found in the acidic lakes were typical of oligotrophic systems in general, regardless of pH, and similar to those found in lake surveys in Scandinavia and Eastern Canada. Potamogeton confervoides Reichenb., Scirpus subterminalis Torr., Sphagnum spp. and Utricularia geminiscapa Benj. were the only species that were primarily exclusive to the acidic lakes surveyed. In contrast to the results of Scandinavian studies, Sphagnum was found to be a major component of the plant cover in only two of the five acidic lakes.