Energy Flow within Streams Following Wildfire: A Progress Report

Backsen C. 2007. Energy Flow within Streams Following Wildfire: A Progress Report. 2007 REU Internship. Augustana College, Sioux Falls, SD

Macroinvertebrates and fish were collected in July and August of 2007. Macroinvertebrates were collected by kicknet or D-net sampling. Contrary to a similar stable isotope study performed in 1993, analysis of 2007 samples revealed no significant difference between isotopic values (d15N and d13C) of consumers from fire-impacted streams compared to reference streams. By contrast, in 1993(5 years after the fire) macroinvertebrates and fish from fire-impacted sites were significantly more enriched in 15N and depleted in 13C than consumers from forested reference sites (P< 0.001). The post-fire isotopic shift in consumers was consistent with increased utilization of algae and/or other autochthonous food sources together with decreased reliance on terrestrial leaf litter and other allochthonous food sources. Such a post-fire shift from a detritus-based to a periphyton-based food web fit predictions of the River Continuum Concept following canopy removal and nutrient enrichment. The 2007 data provide evidence that after 19 years, input of terrestrial and aquatic plant material to stream food webs has “recovered” to pre-fire conditions

Type
Unpublished Report
Authors
Backsen, Chad
Date of Issue
2007
Publisher
2007 REU Internship
Units
GLAC
Keywords
Flathead Lake Biological Station, Fluvial Ecosystems, Food Webs, Macroinvertebrates, Nyack Creek, REU, Streams, Wildfire

Collections

Browse the catalog