Effects of forest fires on headwater streamflow and the habitat suitability for benthic macroinvertebrates

ABSTRACT

We modelled hydrological, hydraulic and habitat suitability changes in a Mediterranean catchment after a wildfire. Gauged pre/post-fire hourly discharges were used to assess actual pre/post-fire hydrological conditions. To remove the weather variability effect, daily pre/post-fire discharges were simulated under the same weather conditions. An eco-hydraulic model was employed to calculate flow velocities, water depths and macroinvertebrate habitat suitability at various discharges across a 165 m long reach. The fire increased the magnitude and frequency of peak velocities and depths by 6.5–475%. Increased post-fire rainfall exacerbated hydrological-hydraulic extremes. However, the short duration of post-fire extremes led to small impacts on the habitat suitability for macroinvertebrates, which were stressed for a maximum 18.4% of the time after the fire (350 days in five years). In small Mediterranean-climate headwaters, after wildfires, less frequent streamflow becomes more frequent, high and of short duration. Macroinvertebrates largely resist such short-term, low-magnitude hydrological-hydraulic changes.

KEYWORDS:

• hydrological response
• hydraulic response
• benthic invertebrates
• wildfire
• streamflow
• habitat modelling

Editor S. ArchfieldAssociate Editor S. Kampf

Editor S. ArchfieldAssociate Editor S. Kampf

Acknowledgements

Dr Christina Papadaki is thankful to the “Greek State Scholarships Foundation (IKY)” for co-funding part of this work.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/02626667.2022.2081508

Additional information

Funding

This work was supported by the State Scholarships Foundation [MIS-5033021 (2019-050-0503-18338)]. This research is co-financed by Greece and the European Union (European Social Fund – ESF) through the Operational Programme “Human Resources Development, Education and Lifelong Learning” in the context of the project “Reinforcement of Postdoctoral Researchers–2nd Cycle” (MIS – 5033021), implemented by the State Scholarships Foundation (IKY).