A1 Journal article (refereed)
Species interactions, environmental gradients and body size shape population niche width (2022)

Eloranta, A. P., Finstad, A. G., Sandlund, O. T., Knudsen, R., Kuparinen, A., & Amundsen, P. (2022). Species interactions, environmental gradients and body size shape population niche width. Journal of Animal Ecology, 91(1), 154-169. https://doi.org/10.1111/1365-2656.13611

JYU authors or editors

Publication details

All authors or editors: Eloranta, Antti P.; Finstad, Anders G.; Sandlund, Odd Terje; Knudsen, Rune; Kuparinen, Anna; Amundsen, Per‐Arne

Journal or series: Journal of Animal Ecology

ISSN: 0021-8790

eISSN: 1365-2656

Publication year: 2022

Publication date: 17/10/2021

Volume: 91

Issue number: 1

Pages range: 154-169

Publisher: Wiley-Blackwell

Publication country: United Kingdom

Publication language: English

DOI: https://doi.org/10.1111/1365-2656.13611

Research data link: https://datadryad.org/stash/dataset/doi:10.5061/dryad.gf1vhhmqz

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/78593


Competition for shared resources is commonly assumed to restrict population-level niche width of coexisting species. However, the identity and abundance of coexisting species, the prevailing environmental conditions, and the individual body size may shape the effects of interspecific interactions on species’ niche width.
Here we study the effects of inter- and intraspecific interactions, lake area and altitude, and fish body size on the trophic niche width and resource use of a generalist predator, the littoral-dwelling large, sparsely-rakered morph of European whitefish (Coregonus lavaretus; hereafter LSR whitefish). We use stable isotope, diet and survey fishing data from 14 subarctic lakes along an environmental gradient in northern Norway.
The isotopic niche width of LSR whitefish showed a humped-shaped relationship with increasing relative abundance of sympatric competitors, suggesting widest population niche at intermediate intensity of interspecific interactions. The isotopic niche width of LSR whitefish tended to decrease with increasing altitude, suggesting reduced niche in colder, less productive lakes.
LSR whitefish typically shifted to a higher trophic position and increased reliance on littoral food resources with increasing body size, although between-lake differences in ontogenetic niche shifts were evident. In most lakes, LSR whitefish relied less on littoral food resources than coexisting fishes and the niche overlap between sympatric competitors was most evident among relatively large individuals (>250 mm). Individual niche variation was highest among >200 mm long LSR whitefish, which likely have escaped the predation window of sympatric predators.
We demonstrate that intermediate intensity of interspecific interactions may broaden species’ niche width, whereas strong competition for limited resources and high predation risk may suppress niche width in less productive environments. Acknowledging potential humped-shaped relationships between population niche width and interspecific interactions can help us understand species’ responses to environmental disturbance (e.g., climate change and species invasions) as well as the driving forces of niche specialization.

Keywords: aquatic ecosystems; food webs; types and species; interaction; populations; ecological niche; nutrition; life cycle (natural science); size; Coregonus lavaretus

Free keywords: diet selection; high-latitude lakes; individual specialization; niche expansion; ontogeny; resource competition; salmonid; trophic niche

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Last updated on 2022-05-04 at 08:26