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Spatiotemporal variability of abundance size-spectra in streams across North America
  • Justin Pomeranz,
  • Jeff Wesner
Justin Pomeranz
University of Canterbury
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Jeff Wesner
University of South Dakota
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The distribution of abundance and biomass within ecological communities is related to trophic transfer efficiency from prey to predators. While it is considered to be one of the few consistent patterns in ecology, spatiotemporal variation of this relationship across continental-scale environmental gradients is unknown. Using a database of stream communities collected across North America (18-68° N latitude, -4 to 25°C mean annual temperature) over 3 years, we constructed 162 mass-abundance relationships (i.e. size spectra). Size-spectra slopes declined (became steeper) with increasing temperature. However, the magnitude of change was relatively small, with median slopes changing from -1.2 to -1.3 across a 29°C range in mean annual temperature. In contrast, total community biomass increased 3-fold over the temperature gradient. Our study suggests strong conservation of abundance size-spectra in streams across broad natural environmental gradients. This supports the emerging use of size-spectra deviations as indicators of ecosystem health.

Peer review status:UNDER REVIEW

15 Oct 2020Submitted to Ecology Letters
16 Oct 2020Assigned to Editor
16 Oct 2020Submission Checks Completed
19 Oct 2020Review(s) Completed, Editorial Evaluation Pending