Selective consequences of catastrophes for growth rates in a stream-dwelling salmonid
Authored by Jarl Giske, Simone Vincenzi, Marc Mangel, Alain J Crivelli, William H Satterthwaite
Date Published: 2012
DOI: 10.1007/s00442-011-2096-8
Sponsors:
United States National Oceanic and Atmospheric Administration (NOAA)
Fisheries Ecology Division
Platforms:
No platforms listed
Model Documentation:
ODD
Flow charts
Mathematical description
Model Code URLs:
Model code not found
Abstract
Optimal life histories in a fluctuating environment are likely to differ
from those that are optimal in a constant environment, but we have
little understanding of the consequences of bounded fluctuations versus
episodic massive mortality events. Catastrophic disturbances, such as
floods, droughts, landslides and fires, substantially alter the
population dynamics of affected populations, but little has been done to
investigate how catastrophes may act as a selective agent for
life-history traits. We use an individual-based model of population
dynamics of the stream-dwelling salmonid marble trout (Salmo marmoratus)
to investigate how trade-offs between the growth and mortality of
individuals and density-dependent body growth can lead to the
maintenance of a wide or narrow range of individual variation in body
growth rates in environments that are constant (i.e., only demographic
stochasticity), variable (i.e., environmental stochasticity), or
variable with catastrophic events that cause massive mortalities (e.g., flash floods). We find that occasional episodes of massive mortality can
substantially reduce persistent variability in individual growth rates.
Lowering the population density reduces density dependence and allows
for higher fitness of more opportunistic strategies (rapid growth and
early maturation) during the recovery period.
Tags
Atlantic salmon
Population-dynamics
Brown trout
Density-dependence
Natural-populations
Phenotypic selection
Dependent individual growth
Marble trout
Variable
environments
Desert stream