As with any area possessing natural beauty, however, the beautiful and species-rich North Carolina mountains have problems. In numerous cases humans inadvertently initiated chains of events that have had dire consequences on the natural world. The unintentional introduction in 1904 of a chestnut fungus (Cryphonectria parasitica) from China devastated the American chestnut (Castanea dentata) and eliminated this magnificent and once dominant tree from eastern North America. Estimated to comprise 40 percent of the temperate deciduous forests before the blight, the chestnut tree's annual mast crop was a very important food source for wildlife.
In recent times the introduction from Europe of two adelgid insects has wreaked havoc on fir and hemlock forests. As a result, in the last 20 years the pristine Fraser firs on Mount Mitchell have been mostly lost. In addition, airborne heavy metals from factories hundreds of miles distant have interfered with the physiology of many plants, and acid rain has hurt many forest species.
Man's effect on the environment may help some species while it hurts others. While it is true that cutting the forests has produced more deer—because deer like openings—fragmenting the forests has had a devastating effect on songbirds. Recent analysis of 25-year studies of songbird populations, for example, indicate that 50 percent of such species as scarlet tanagers, as well as several species of thrushes, vireos, and warblers, have been lost in our northeastern states largely because we created huge openings in forest lands. In the case of songbirds, the effect is complicated. Some species, scientists now believe, simply cannot reproduce in open areas. Still more insidious is the fact that many songbirds are being decimated by the intrusion of a forest-edge bird, the brown-headed cowbird (Molothrus ater). This species has used openings made by humans to invade areas that were once deep in the forests. The cowbird parasitizes the nests of songbirds by laying its eggs in their nests. Cowbird young hatch first and dominate the other nestlings. Songbird parents will feed the cowbird young at the expense of their own young, often causing the complete failure of many songbirds' reproduction.
Even the acts of amateur gardeners sometimes have deleterious effects on wildlife. When pesticides are used in our gardens, we destroy not only the intended victims but a host of other useful insects as well, and, through food chains, destroy unintended victims such as songbirds and even predator species such as hawks and owls.
The greatest problem right now is setting aside habitats for wild creatures. Western North Carolina is fortunate in that its land and waterways have not been completely overdeveloped. But citizens must be ever vigilant. The North Carolina mountains, though, still hold exciting natural treasures. Readers should use this book to visit some of the high-altitude habitats mentioned. These mountains still have enough natural interest to engage naturalists for several lifetimes.