Periphytic algal species composition differences in thermally altered artificial streams

Initial studies of periphytic algal community structure on natural substrates in the six artificial streams at the Flowing Streams Laboratory were discussed in last year's annual report. These studies were continued throughout 1977 to determine seasonal patterns. The results indicated that: continuous temperature elevations of 50C or 7.50C could cause substantial changes in the seasonal periodicity of major algal taxa in a Southeastern U.S. blackwater stream, and a continuous temperature elevation of 12.50C seriously affected algal community structure