Spatial and seasonal variability of forested headwater stream temperatures in western Oregon, USA

Abstract

Thermal regimes of forested headwater streams control the growth and distribution of various aquatic organisms. In a western Oregon, USA, case study we examined: (1) forested headwater stream temperature variability in space and time; (2) relationships between stream temperature patterns and weather, above-stream canopy cover, and geomorphic attributes; and (3) the predictive ability of a regional stream temperature model to account for headwater stream temperature heterogeneity. Stream temperature observations were collected at 48 sites within a 128-ha managed forest in western Oregon during 2012 and 2013. Headwater stream temperatures showed the greatest spatial variability during summer (range up to 10 C) and during cold and dry winter periods (range up to 7.5 C), but showed less spatial variability during spring, fall and wet winter periods (range between 2 and 5 C). Distinct thermal regimes among sites were identified; however, geomorphic attributes typically used in regional stream temperature models were not good predictors of thermal variability at headwater scales. A regional stream temperature model captured the mode of mean August temperatures observed across the study area, but overpredicted temperatures for a quarter of the sites by up to 2.8 C. This study indicates considerable spatial thermal variability may occur at scales not resolved by regional stream temperature models. Recognizing this sub-landscape variability may be important when predicting distributions of aquatic organisms and their habitat under climate and environment change scenarios.

Keywords

Stream temperature; Stream networks; Headwater; Pacific Northwest; Aquatic habitat

Published in

Aquatic Sciences - Research Across Boundaries
2017, Volume: 79, number: 2, pages: 291-307 Publisher: SPRINGER BASEL AG

SLU Authors

• Leach, Jason

  • Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
    
  • University of British Columbia

Sustainable Development Goals

SDG13 Climate action


UKÄ Subject classification

Oceanography, Hydrology, Water Resources


Publication identifier

DOI: https://doi.org/10.1007/s00027-016-0497-9

Permanent link to this page (URI)

https://res.slu.se/id/publ/94202