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La Interacción entre Variabilidad Climática y Denso Dependencia en la Viabilidad Poblacional de Oncorhynchus tshawytscha
Author(s) -
ZABEL RICHARD W.,
SCHEUERELL MARK D.,
McCLURE MICHELLE M.,
WILLIAMS JOHN G.
Publication year - 2006
Publication title -
conservation biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.2
H-Index - 222
eISSN - 1523-1739
pISSN - 0888-8892
DOI - 10.1111/j.1523-1739.2005.00300.x
Subject(s) - population viability analysis , chinook wind , oncorhynchus , density dependence , extinction (optical mineralogy) , population , threatened species , environmental science , population density , climate change , population size , ecology , biology , fishery , fish <actinopterygii> , habitat , demography , endangered species , paleontology , sociology
The viability of populations is influenced by driving forces such as density dependence and climate variability, but most population viability analyses (PVAs) ignore these factors because of data limitations. Additionally, simplified PVAs produce limited measures of population viability such as annual population growth rate (λ) or extinction risk. Here we developed a “mechanistic” PVA of threatened Chinook salmon ( Oncorhynchus tshawytscha ) in which, based on 40 years of detailed data, we related freshwater recruitment of juveniles to density of spawners, and third‐year survival in the ocean to monthly indices of broad‐scale ocean and climate conditions. Including climate variability in the model produced important effects: estimated population viability was very sensitive to assumptions of future climate conditions and the autocorrelation contained in the climate signal increased mean population abundance while increasing probability of quasi extinction. Because of the presence of density dependence in the model, however, we could not distinguish among alternative climate scenarios through mean λ values, emphasizing the importance of considering multiple measures to elucidate population viability. Our sensitivity analyses demonstrated that the importance of particular parameters varied across models and depended on which viability measure was the response variable. The density‐dependent parameter associated with freshwater recruitment was consistently the most important, regardless of viability measure, suggesting that increasing juvenile carrying capacity is important for recovery.