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Implications[edit]

One of the major ways that habitat fragmentation affects biodiversity is by reducing the amount of suitable habitat available for organisms. Habitat fragmentation often involves both habitat destruction and actual subdivision of previously continuous habitat.[1] Plants and other sessile organisms are disproportionately affected by some types of habitat fragmentation because they cannot respond quickly to the altered spatial configuration of the habitat.[2]

As the remaining habitat patches are smaller, they tend to support smaller populations of species.[3] Small populations are at an increased risk of a variety of genetic consequences that influence their long-term survival.[4] Remnant populations contain a subset of the genetic diversity found in the previously continuous habitat in what is described as the founder effect. Processes that act upon underlying genetic diversity such adaptation have a smaller pool of fitness-maintaining alleles to survive in the face of environmental change.

Populations can maintain genetic diversity through the process of migration. In continuous habitats, migrants have few barriers to establish themselves in suitable sites. In fragmented habitats however, the separation between suitable sites disrupts gene flow and its capacity to supplement the reduced genetic diversity of remnant populations. Inbreeding becomes a concern in populations living in habitat fragments when their level of homozygosity increases. This facilitates the expression of deleterious alleles that reduce the fitness of the population called inbreeding depression.

  1. ^ Fahrig, Lenore (November 2003). "Effects of Habitat Fragmentation on Biodiversity". Annual Review of Ecology, Evolution, and Systematics. 34 (1): 487–515. doi:10.1146/annurev.ecolsys.34.011802.132419.
  2. ^ Lienert, Judit (July 2004). "Habitat fragmentation effects on fitness of plant populations – a review". Journal for Nature Conservation. 12 (1): 53–72. doi:10.1016/j.jnc.2003.07.002.
  3. ^ Simberloff, Daniel (1 January 1998). "Small and Declining Populations". Conservation Science and Action. Blackwell Publishing Ltd.: 116–134. doi:10.1002/9781444313499.ch6/summary.
  4. ^ Frankham, Richard; Ballou, Jonathan D.; Briscoe, David A. (2009). Introduction to conservation genetics (2nd ed. ed.). Cambridge: Cambridge University Press. ISBN 9780521702713. {{cite book}}: |edition= has extra text (help)