Effects of calcite treatment on primary producers in acidified adirondack lakes - response of macrophyte communities

Abstract

The effects of limestone addition on two Clearwater, acidic lakes in the Adirondack mountain region of New York state were studied by investigators participating in the Lake Acidification Mitigation Project (LAMP). Biomass and percent cover of the dominant macrophyte species (Utricularia purpurea) were recorded during the period of maximal standing crop for one year prior to and three years following calcite addition. The progressive dieback of U. purpurea following lake treatment suggests that this species does not tolerate changes in water quality associated with calcite addition. Calcite treatment may affect macrophyte growth by reducing the availability of dissolved carbon dioxide (CO2). For species that rely exclusively on carbon dioxide as a carbon source for photosynthesis, calcite addition may reduce growth rates, since carbon dioxide is depleted during calcite dissolution. Reduced light penetration during the post-treatment period may also contribute to the decline of the U. purpurea population. © 1988 North American Lake Management Society.