She was probably referring to ex-situ conservation as a way to complement in-situ conservation. Indeed, if a population is endangered and fragmentation it thought to be one of the main factors causing the decline, it can sometime be hard to restore the habitat in a way that would permit the population reestablishment (in-situ conservation). Ex-situ conservation can therefore permit to protect some individuals. Then, we could reintroduce individuals to their natural habitats later on, and this could give us more time to restore the habitat.
If you want a good example of how hard it can be to restore the habitat to permit population reestablishment, have a look a the Caribou situation in the north of Québec.
If your question is about how fragmentation is affecting species then it's a very very large subject... it can reduce gene flow, induce stress that could leads to lower reproductive success, etc.
Hope this helps.