The corridor itself affects the Reserve through the continuing presence of the service road that we are on. Roads themselves fundamentally change an area. This isn't a surprise. Look out your front door and you immediately realize the threat that traffic on a road has to your children, and you don't allow them on the road until they are old enough to be careful. Animals and plants are also fundamentally affected by roads.
Many animals never learn road safety, and die simply due to the presence of roads.
A huge mountain lion barrier had to be built on I-15 just east of here in order to prevent mountain lion deaths. Hundreds of toads are killed with every rainstorm on just one road in the Fallbrook area, the De Luz Road, since they actually come out to sit on the road and absorb the moisture that is easily available during and immediately after rains. Fortunately, since traffic on the roads in SMER is extremely light, this isn't a problem here. However, other animals won't cross a road at all, and the road serves to fundamentally restrict their habitat. If the road creates too small a habitat, the animal will become extinct there.