Dr. Richard Vollenweider and the Great Lakes

摘要

It was in 1968 when Swiss-born Richard Vollenweider, with support from the Organization for Economic Cooperation and Development (OECD), published his landmark study on eutrophication of lakes (Vollenweider, 1968). He had investigated nutrient loadings and basic physical characteristics of a number of lakes, particularly in Europe and North America. The fundamental relationship he then developed was the comparison of trophic state with total phosphorus loading in gm m~(-2) yr~(-1), where m~2 is the lake surface area, plotted against the lake mean depth. He was then able to show in a graph, a band of values that separated oligotrophic lakes, with less loading, from eutrophic lakes with greater phosphorus loading. The lower oligotrophic side of the band was labelled "admissible limits" and the upper side "dangerous limits." Vollenweider had also developed a similar graph for nitrogen loadings.