Skip to main content
U.S. flag

An official website of the United States government

Increasing accuracy of dispersal kernels in grid-based population models

August 29, 2011

Dispersal kernels in grid-based population models specify the proportion, distance and direction of movements within the model landscape. Spatial errors in dispersal kernels can have large compounding effects on model accuracy. Circular Gaussian and Laplacian dispersal kernels at a range of spatial resolutions were investigated, and methods for minimizing errors caused by the discretizing process were explored. Kernels of progressively smaller sizes relative to the landscape grid size were calculated using cell-integration and cell-center methods. These kernels were convolved repeatedly, and the final distribution was compared with a reference analytical solution. For large Gaussian kernels (σ > 10 cells), the total kernel error was <10−11 compared to analytical results. Using an invasion model that tracked the time a population took to reach a defined goal, the discrete model results were comparable to the analytical reference. With Gaussian kernels that had σ ≤ 0.12 using the cell integration method, or σ ≤ 0.22 using the cell center method, the kernel error was greater than 10%, which resulted in invasion times that were orders of magnitude different than theoretical results. A goal-seeking routine was developed to adjust the kernels to minimize overall error. With this, corrections for small kernels were found that decreased overall kernel error to <10−11 and invasion time error to <5%.

Citation Information

Publication Year 2011
Title Increasing accuracy of dispersal kernels in grid-based population models
DOI 10.1016/j.ecolmodel.2010.11.023
Authors D. H. Slone
Publication Type Article
Publication Subtype Journal Article
Series Title Ecological Modelling
Index ID 70003768
Record Source USGS Publications Warehouse
USGS Organization Southeast Ecological Science Center