Finally, the nest site microhabitat structure could be compromised by nests near edges being less concealed by vegetation than core nests, which may lead to increased predation there. It turns out that the percentage of forest cover at the landscape scale influences predation levels and the existence of edge effects. Edge effects varied depending upon landscape style. In moderately fragmented landscapes predation levels were significantly higher in edge habitats than in core habitats. There was no detection of higher predation rates in unfragmented landscapes.
Diversity is lower in smaller fragments for many reasons.
First, as fragment size decreases, so does the patch capacity. Thus, in small populations viability will decrease and eventually cause extinction. Small populations are also more susceptible to fluctuations, and more likely to suffer from genetic drift and inbreeding. This causes a reduction in genetic variation, increasing homozygosity, therefore eventually reducing fitness. There are many possible underlying mechanisms of species loss in forest fragments and they need to be explored in more depth.