" . . .the benefits of landscape corridors, the strips of habitat that connect isolated patches of habitat, extend well beyond those borders."
Beneficial Plant 'Spillover' Effect Seen From Landscape Corridors: article here.
And an amazing corridor success story here.
"It took a while for people to hear our answer: No, we do not want to preserve that ugly mess we want to restore it to something beautiful. We want to restore native vegetation to those cut and fill slopes on the Coal Canyon side of the freeway, and to the stables and the raceway. We want to rip the pavement and lighting out of this underpass. Then we want to take Coal Canyon out of its concrete tomb and put at least half of its flow back into that underpass. We don’t want to preserve that vehicle underpass we want to transform it into a waterway and an underpass for animals, plants, and people.
"The restoration is really the most exciting part of this project. So often conservationists in California spend their lives fighting one dismal project after another, trying to slow the rate at which things get worse. But this project is different. It is not working AGAINST something bad it is working FOR something good. Restoring a functional linkage for all plants and animals in what is now a degraded area is a powerful and positive thing to do. I am not aware of any other effort to restore a biological corridor with this level of regional importance to so many species. This effort will set a global precedent. Conservation-minded citizens and public servants around the world will soon be able to look at Coal Canyon as an inspiring example of how an ecological mistake was corrected through thoughtful public action. "
They did it! They bought up 600-plus acres and transformed the underpass for the use of migrating animals.