You are here: Home
/ Publication Information
Title: Numerically exploring habitat fragmentation effects on populations using cell-based coupled map lattices
Author: Bevers, Michael; Flather, Curtis H.;
Source: Theoretical population biology. 55(1): 61-76
Publication Series: Miscellaneous Publication
Description: We examine habitat size, shape, and arrangement effects on populations using a discrete reaction-diffusion model. Diffusion is modeled passively and applied to a cellular grid of territories forming a coupled map lattice. Dispersal mortality is proportional to the amount of nonhabitat and fully occupied habitat surrounding a given cell, with distance decay. After verifying that our model produces the results expected for single patches of uniform habitat, we investigate heterogeneous and fragmented model landscapes. In heterogeneous single-patch systems near critical patch size, populations approach Gaussian spatial distributions with total population constrained by the capacity of the most limiting cell. In fragmented habitat landscapes, threshold effects are more complex and parametrically sensitive. The results from our experiments suggest the following: the ability to achieve persistence in hyper-dispersed patchy habitats by adding similarly fragmented patches requires meeting threshold reproduction rates; persistent metapopulations in which no local population is individually persistent appear when dispersal distances and reproduction rates are both high, but only within narrow parameter ranges that are close to extinction thresholds; successful use of stepping-stone patches to support metapopulation systems appears unlikely for passively diffusing species; elongated patches offer early colonization advantages, but blocky patches offer greater population resilience near extinction thresholds. A common theme running through our findings is that population viability estimates may depend on our ability to determine when population and habitat systems are approaching extinction threshold conditions.
Keywords: spatial models, dispersal, population persistence, critical patch size, critical patch arrangement, spatial heterogeneity, reaction-diffusion, metapopulations
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
- You may send email to firstname.lastname@example.org to request a hard copy of this publication. (Please specify exactly which publication you are requesting and your mailing address.)
XML: View XML
Bevers, Michael; Flather, Curtis H. 1999. Numerically exploring habitat fragmentation effects on populations using cell-based coupled map lattices. Theoretical population biology. 55(1): 61-76
Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility