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Broad‐scale habitat classification variables predict maximum local abundance for native but not non‐native trout in New York streams
Author(s) -
Alexiades Alexander V.,
Fisher William L.
Publication year - 2015
Publication title -
aquatic conservation: marine and freshwater ecosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.95
H-Index - 77
eISSN - 1099-0755
pISSN - 1052-7613
DOI - 10.1002/aqc.2476
Subject(s) - brown trout , trout , salvelinus , abundance (ecology) , salmo , relative species abundance , habitat , fontinalis , quantile regression , ecology , environmental science , biology , fishery , fish <actinopterygii> , statistics , mathematics
Predicting species distributions at the landscape level has many applications in fish ecology, management, and conservation, yet generating accurate predictions remains a challenge to fish ecologists. Areas of the landscape with higher environmental suitability should have higher relative abundance, although the predictive capability of this relationship might be limited because environmental suitability ignores other factors such as biotic interactions and stochastic events. These factors could contribute to a species being absent or at low abundance in a site with high environmental suitability. Owing to the potential influence of non‐environmental and stochastic factors on relative abundance, modelled environmental suitability should be a better predictor of maximum abundance (i.e. the ceiling of scattered data) than mean relative abundance because ecosystem complexities often preclude a simple monotonic response. To evaluate this assumption, environmental suitability was predicted for 55 944 stream reaches in New York State using native brook trout ( Salvelinus fontinalis ) and non‐native brown trout ( Salmo trutta ) occurrence data and a suite of four broad‐scale habitat factors. Estimates of suitability were then used to test the relationship with the upper limits of abundance using quantile regression. As predicted, there was a significant positive relationship with maximum abundance for native brook trout at the upper quantiles; however, this relationship did not extend to non‐native brown trout. These findings indicate that broad‐scale habitat factors can predict maximum abundance of a native stream‐dwelling trout and produced environmental suitability maps that could be useful for brook trout conservation. These findings could be used to predict trout occurrence in unsurveyed stream reaches with the highest abundance limits, which could be used to set conservation priorities and provide benchmarks of habitat potential for monitoring programmes as well as identify threats to environmental suitability from anthropogenic sources. Copyright © 2014 John Wiley & Sons, Ltd.