What is habitat fragmentation?
Lets start with the basics.
-What is a habitat? Google defines a habitat as the natural home or environment of an animal, plant, or other organism.
-Okay, so then what is habitat fragmentation? The answer to this question is not as straight-forward as one might think. Reputable sources and scientists alike actually disagree on the exact definition of habitat fragmentation [1], [2]. This being the case, most scientists agree that habitat fragmentation can be described as a habitat being apportioned into smaller, isolated patches, with an increase in the edge to habitat ratio.
Figure 1: Habitat fragmentation, the production of isolated patches
Here (top) we have the natural habitat (before any disturbance)
The now fragmented habitat (bottom). Each one of the four squares are considered the newly isolated patch.
Figure by Dan Anderson
Figure 2: Habitat fragmentation, increasing the edge to patch ratio
Let's use the same diagram as before, but now look at the area of habitat to edge ratio.
Here is the original habitat with an edge of 24 ft. and a habitat area of 64 ft. squared. This gives an edge to area ratio of 3:8
Now consider the four new patches formed after fragmentation. They each have an edge of 16 ft. with an area of 16 ft. squared. This gives an edge to area ratio of 1:1
Figure by Dan Anderson
This figure represents the idea that the habitats that are fragmented will increase in the edge to area ratio. Realistically, habitats that are fragmented would actually decrease in area as well as increase in edge, because the act of fragmentation actually takes up habitat area as well, which in turn would further increase the edge to area ratio.
