Measuring Nutrient Spiralling in Streams

Abstract

Nutrient cycling in streams involves some downstream transport before the cycle is completed. The path traveled by a nutrient atom in passing through the cycle can be visualized as a spiral. As an index of the spiralling process, spiralling length, defined as the average distance associated with 1 complete cycle of a nutrient atom, is introduced. This index provides a measure of the utilization of nutrients relative to the available supply from upstream. Using 32P as a tracer, a spiralling length of 193 m was estimated for P in a small woodland stream.