Measuring Nutrient Spiralling in Streams

TLDR

Nutrient cycling in streams involves downstream transport before the cycle completes, so a nutrient atom’s path can be visualized as a spiral. The study introduces spiralling length as an index of the spiralling process. Spiralling length is defined as the average distance associated with one complete cycle of a nutrient atom. Using 32P as a tracer, we estimated a spiralling length of 193 m for phosphorus in a small woodland stream, indicating that the index reflects nutrient utilization relative to upstream supply.

Abstract

Nutrient cycling in streams involves some downstream transport before the cycle is completed. Thus, 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, we introduce spiralling length, defined as the average distance associated with one complete cycle of a nutrient atom. This index provides a measure of the utilization of nutrients relative to the available supply from upstream. Using 32 P as a tracer, we estimated a spiralling length of 193 m for phosphorus in a small woodland stream.Key words: downstream transport, nutrient cycling, phosphorus, spiralling, stream