Before we can discuss the effects of fragmentation, we must identify the species likely to be affected. That means identifying species in which fragmentation will alter the distribution of populations, the migration rates among populations, and the sizes of local populations.
Lets start with the last one first.
Furthermore, not all plants or animals that are widely distributed will suffer the effects of fragmentation. Those that are patchily distributed are already fragmented. Unless fragmentation disrupts patterns of migration among the populations that remain, it will have fewer effects than it will on those that are continuously distributed. Think about what this means, though. In short, whatever the effects of fragmentation are, they may be exhibited in a minority of species, but that minority of species will be the ones that have the largest impact on the structure and function of ecosystems in which they occur.