Abstract
Climate-induced plasticity in functional traits has received recent attention due to the immense importance phenotypic variation plays in population level responses. Here, we explore the effect of different climate-change scenarios on lentic populations of a freshwater ectotherm, the brown trout (Salmo trutta L.), through climate effects on functional traits. We first parameterize models of climate variables on growth, spawning probability and fecundity. The models are utilized to inform a dynamic age-structured projection matrix, enabling long-term population viability projections under climate and population density variation. Ambient temperature and winter conditions had a substantial effect on population growth rate. In general, warmer summer temperatures resulted in faster growth rates for young fish but ended in smaller size at age as fish got older. Increasing summer temperatures also induced maturation at younger age and smaller size. In addition, we found effects of first-year growth on later growth trajectories for a fish, indicating that environmental conditions experienced the first year will also influence size at age later in life. At the population level, increasing temperatures average (up to 4 °C increase in areas with mean summer temperature at approximately 12 °C) resulted in a positive effect on population growth rate (i.e. smaller but more fish) during climate simulations including increasing and more variable temperatures.
Highlights
Climate-induced plasticity in functional traits has received recent attention due to the immense importance phenotypic variation plays in population level responses
Through the developed population tool, we explore the following research questions: How would an allopatric lentic brown trout population react to an increase in mean summer temperature, as well as increased variation in annual summer temperature, and how would added changes in winter conditions alter population dynamics further?
Our results show that changes in summer temperatures and winter conditions, and size at age and spawning probability norm, can have profound population-level consequences for the studied sub artic brown trout communities
Summary
Climate-induced plasticity in functional traits has received recent attention due to the immense importance phenotypic variation plays in population level responses. An emerging trend with an increasing empirical evidence base for organisms with indeterminate growth seems to be related to the temperature-size r ule[6], where organisms exposed to warmer temperatures grow faster through ontogeny, but reach a smaller adult s ize[7,8,9,10,11] These effects might be especially pronounced in systems where there are few opportunities for behavioral thermoregulation, and for ectotherms, as temperature and growth are directly connected. All these life-history traits are allowed to interact and react to changes in the environmental variables, which dictate the parameter range in an age-structured matrix population m odel[23] to forecast changes in population growth rate. Through the developed population tool, we explore the following research questions: How would an allopatric lentic brown trout population react to an increase in mean summer temperature, as well as increased variation in annual summer temperature, and how would added changes in winter conditions alter population dynamics further?
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
