Work

Climate‐moderated responses to wildfire by macroinvertebrates and basal food resources in montane wilderness streams

Year: 2014

Type: article

Abstract: Changes in both climate and fire frequency have been documented but the combined effects of these are poorly understood in freshwater systems, thus making it imperative for long‐term studies in pristine habitats to quantify climate‐mediated wildfire effects in lotic systems. We quantified the response of invertebrates and basal food resources in 6 wilderness streams in central Idaho USA for 8 years pre‐fire and 5 years post‐fire. We found that a shift in climate toward increased temperature and reduced peaks in snow‐melt runoff moderated the effects of wildfire on basal food resources and altered invertebrate community structure and annual variation. Taxon richness significantly increased over the 13‐year study period at all sites regardless of fire. Post‐fire changes were accompanied by an increase in the relative abundances of chironomid midges and Baetis mayflies, which generally are regarded as disturbance‐adapted taxa. Ordination analysis of invertebrate community biomass showed that both unburned and burned streams differed between pre‐ and post‐fire years and combined, our results suggest that the effects of climate ameliorated the effects of fire. We found significant correlations between community structure and climatic variables of precipitation, temperature, and discharge in all streams. Our findings support previous studies that attribute a large part of negative fire effects on stream ecosystems to major increases in runoff from sparsely vegetated uplands and attendant restructuring of channels and substrata. However, we found during a period of climate warming and reduction in snow‐melt runoff, these adverse effects were suppressed resulting in increases in basal food resources and invertebrate density and biomass following fire. Our results show the importance of long‐term studies in quantifying community changes in responses to disturbance under a changing climate in lotic ecosystems.

Source: Ecosphere

DOI: 10.1890/es13-00236.1

Authors: Amanda T. Rugenski, G. Wayne Minshall

Institutions: Southern Illinois University Carbondale, Arizona State University, Idaho State University

Language: English

Topic: Freshwater macroinvertebrate diversity and ecology

Subfield: Ecology

Field: Environmental Science

Domain: Physical Sciences

SDGs: Life on land, Climate action

Open Access status: gold

Estimated APC paid: $2,430