This award supports four scientists from the Center of Limnology and Department of Botany of the University of Wisconsin, led by Professor Michael S. Adams, to collaborate in several studies of mutual interest with Dr. Max Tilzer and others of the Institute of Limnology of the University of Konstanz. The U.S. participants are basing their collaboration on their NSF-funded Long-Term Ecological Research (LTER) project that focuses on the physical, chemical and biological limnology of several small lakes in the Northern Highland Lake district of Wisconsin. The Germans, in contrast, are studying the limnology of a deep, large lake in southern Germany, Lake Konstanz (the Bodensee.) One topic of emphasis in both large research programs is the role of light scattering and absorption by algal and non-algal materials in controlling primary productivity (the growth of the suspended phytoplanktonic algae.) The collaborating scientists will also compare their different conceptual models of primary productivity and their different methods of measuring it. Both groups are also involved in long term studies of the impact of acid rain on aquatic systems. They intend to compare the insights they have gained. The German project leader is an expert on phytoplankton quantum efficiency. The US methods will be strengthened and benefit from accurate interpretations of quantum efficiency. The US team uses a sophisticated laboratory incubation method for determining primary productivity that permits great experimental and analytical flexibility. The German group uses the older "in situ" procedures that give accurate field measurements but lack experimental flexibility. The lakes they use for field study differ in a number of ways that make for interesting comparisons. The proposed collaboration will enhance understanding of the natural variability of aquatic systems, of primary productivity methods and models, and of the light climate of lakes. It will also contribute to important on-going research efforts in acid deposition.
