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Explore the impact of climate change on population dynamics using models with range shifts and dispersal mechanisms. Analyze critical speed, extinction risks, and effects of accelerated climate change. Mathematical methods and habitat suitability are examined.
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Non-local Dispersal Models for a Population under Climate Change (Joy) Ying Zhou, Mark Kot Department of Applied Mathematics University of Washington
Population Dynamics Matter Cartoon of a Range Shift
Talk Outline Population Models on Range Shifts under: Constant-speed climate change Accelerated climate change
Organisms of Interest • Well-defined life stages (growth, dispersal) • Growth and dispersal occur in separate time periods • Non-overlapping generations Seedling Egg mass Dispersal Dispersal Seed Adult Larvae Flower Growth Growth Cocoon
Integrodifference equation Assuming no Allee effects Integrodifferenceeqn (IDE) kernel
Climatically Suitable Habitat Habitat shifts Combination of two classical problems Zhou and Kot 2011 Theoretical Ecology
A Steady Range Shift For Small c What Population Dynamics Will We Observe? Zhou and Kot 2011 Theoretical Ecology
Extinction When c Large Zhou and Kot 2011 Theoretical Ecology
Eigenvalue Problem Net reproductive rate Analytic method for “separable” kernels Numerical method “Nystrom’s method” Delves and Wash 1974
Larger Net ReproductiveRate Helps Zhou and Kot 2011 Theoretical Ecology
More Dispersal, But Not Over-dispersal radius Dispersal radius Zhou and Kot 2011 Theoretical Ecology
Clark 1998 Mean deviation Schultz 1998
The “Tail” of The Dispersal Kernel Result for a typical platykurtic kernel Result for a typical leptokurtic kernel Result for a typical leptokurtic kernel Zhou and Kot 2011 Theoretical Ecology
Heterogeneous Habitat Suitability Climatically Suitable Habitat Climatically Suitable Habitat Habitat shifts Habitat quality function Latore et al. 1999
Consider linearized equation For normally distributed habitat quality a Gaussian dispersal kernel
and a special initial condition (Gaussian initial profile), then we have an ansatz Latore et al. 1999 : peak of the pulse : amplitude of the pulse
Accelerated Climate Change Same ansatz
Speed Time T
Comparison of climate deficit vs. For large t
Summary • An integrodifference equation model with shifting boundaries • Critical speed • Acceleration may hurt a lot (more than average)
Thank you! Questions?