Research article - Peer-reviewed, 2021
Size, connectivity and edge effects of stream habitats explain spatio-temporal variation in brown trout (Salmo trutta) density
Tamario, Carl; Degerman, Erik; Polic, Daniela; Tibblin, Petter; Forsman, AndersAbstract
Ecological theory postulates that the size and isolation of habitat patches impact the colonization/extinction dynamics that determine community species richness and population persistence. Given the key role of lotic habitats for life-history completion in rheophilic fish, evaluating how the distribution of swift-flowing habitats affects the abundance and dynamics of subpopulations is essential. Using extensive electrofishing data, we show that merging island biogeography with meta-population theory, where lotic habitats are considered as islands in a lentic matrix, can explain spatio-temporal variation in occurrence and density of brown trout (Salmo trutta). Subpopulations in larger and less isolated lotic habitat patches had higher average densities and smaller between-year density fluctuations. Larger lotic habitat patches also had a lower predicted risk of excessive zero-catches, indicative of lower extinction risk. Trout density further increased with distance from the edge of adjacent lentic habitats with predator (Esox lucius) presence, suggesting that edge- and matrix-related mortality contributes to the observed patterns. These results can inform the prioritization of sites for habitat restoration, dam removal and reintroduction by highlighting the role of suitable habitat size and connectivity in population abundance and stability for riverine fish populations.Keywords
colonization-extinction dynamics; habitat fragmentation; population abundance fluctuations; predation; river connectivityPublished in
Proceedings of the Royal Society B: Biological Sciences2021, volume: 288, number: 1961, article number: 20211255
Publisher: ROYAL SOC
Authors' information
Tamario, Carl
Linnaeus University
Degerman, Erik
Swedish University of Agricultural Sciences, Department of Aquatic Resources
Polic, Daniela
Linnaeus University
Tibblin, Petter
Linnaeus University
Forsman, Anders
Linnaeus University
Sustainable Development Goals
SDG14 Life below water
UKÄ Subject classification
Ecology
Publication Identifiers
DOI: https://doi.org/10.1098/rspb.2021.1255
URI (permanent link to this page)
https://res.slu.se/id/publ/114250