Stream fish energy budgets under differing riparian timber harvest intensities

We conducted field manipulations of eight headwater streams in West Virginia to assess the impact of riparian forest harvest intensity upon the energetic of streams and brook trout.  Four streams each received a 50% and a 90% basal area harvest (BAH) within the streamside management zones.  These treatments opened canopies but did not significantly affect periphyton biomass or aquatic invertebrate biomass or richness.  Terrestrial subsidies of invertebrates were significantly higher in the 90% BAH but this coincided with elevated temperatures relative to reference sections.  We used a stream energy budget approach and a bioenergetics model for brook trout to show that increases in terrestrial subsidies were not sufficient to overcome increased metabolic demands of brook trout due to warmer stream temperatures.  These results suggest that 50% BAH is protective of stream and fish energetic while 90% BAH results in at least short-term decreases in stream fish productivity in Appalachian headwater streams.