The Pond Primeval: Phosphorous and Oxygen in Walden Pond

摘要

A 2001 U.S. Geological Survey collected and organized a huge amount of data about the chemistry of Walden Pond between the years 1995-1999 (inclusive). Among the data were details on two elements that play major roles in the limnology of many ponds: phosphorous and oxygen. This report will show how a simple model can tie together the data on input phosphorous and consumed oxygen. When the modern high levels of phosphorous are removed, the model reveals the probable pattern of the Pond's primeval function in earlier times. The surprising finding is that, even in the late autumn of 1846 when Thoreau lived beside it, Walden Pond, at its deepest points, probably ran out of oxygen.