A keystone species, hemlock, is likely to disappear in many areas of the small stream riparian forest ecosystem.

In the cooler and moister sites, hemlock is a keystone species that has been declining and is projected to decline further. For these forests, the loss of hemlock is likely to change the species assemblage dramatically, with fast-growing generalists like red maple or a variety of invasive species likely to overtake the newly vacated niche.