Extinction threshold

Extinction threshold is a term used in conservation biology to explain the point at which a species, population or metapopulation, experiences an abrupt change in density or number because of an important parameter, such as habitat loss. It is at this critical value below which a species, population, or metapopulation, will go extinct,[1] though this may take a long time for species just below the critical value, a phenomenon known as extinction debt.[2]

Extinction thresholds are important to conservation biologists when studying a species in a population or metapopulation context because the colonization rate must be larger than the extinction rate, otherwise the entire entity will go extinct once it reaches the threshold.[3]

Extinction thresholds are realized under a number of circumstances and the point in modeling them is to define the conditions that lead a population to extinction.[4] Modeling extinction thresholds can explain the relationship between extinction threshold and habitat loss and habitat fragmentation.[5]

  1. ^ Ovaskainen, O. and Hanski, I. 2003:Extinction Threshold in Metapopulation Models, Ann.Zool.Fennic.40:81-97.
  2. ^ Tilman, D.; May, R. M.; Lehman, C. L.; Nowak, M. A. (1994). "Habitat destruction and the extinction debt". Nature. 371 (6492): 65. Bibcode:1994Natur.371...65T. doi:10.1038/371065a0.
  3. ^ Groom, M., Meffe, G. K., and Carroll, C.R. 2000:Principles of Conservation Biology, 3rd Ed, Sinauer Associates.
  4. ^ With, K.A. and King, A.W. 1999:Extinction Thresholds For Species in Fractal Landscapes, Conservation Biology: Vol 13, No.2, pp.314-326.
  5. ^ Fahrig, Lenore. 2002:Effect of Habitat Fragmentation on the Extinction Threshold: A Synthesis, Ecological Applications: Vol.12, No.2, pp.346-353.