What about fires today? Lightning-caused fire is as ancient as the mountains themselves and has always been a part of the forest’s life process. Some tree species actually depend on fire for regeneration, such as the pin cherry. And the heath bald shrubs, such as blueberry and mountain-laurel, prosper after a light burn. Fire is necessary as well to dozens of flowering plants which quickly seed new forest openings the fire creates. We have long viewed fire on wildlands as a catastrophe, and indeed it is often a piteous sight. But the urge to suppress fire completely sometimes results in other unsatisfactory conditions. On many large public land areas limited wildfires are now allowed to burn if they don’t threaten private property or human lives. [Illustration: Fire-fighting airplane] [Illustration: Fire-fighters on the ground] [Illustration: _The Smokies is an ancient land-mass. Its plantlife may have evolved uninterruptedly for more than 200 million years. Continental Ice Age glaciation did not reach this far south, and as the Atlantic Ocean has repeatedly inundated most of North America, the Smokies remained an island._] The Evolution of Abundance Diversity is the biological keynote of the Great Smoky Mountains. Within the national park have been found about 1,500 species of flowering plants, among which are some 100 trees. There are around 2,000 fungi, 50 mammals, 200 birds, and 70 fishes, or more than in the fresh waters of any other national park on our continent. There are about 80 reptiles and amphibians, among which are 22 salamanders, which is probably as many as can be found in any similar-sized area in North America. Present conditions, such as warmth, abundant moisture, and a diversity of environments brought about by the height and dissection of the mountains, are partly responsible for this biotic wealth. But time, the many millions of years this land has been above the sea and south of the ice, has also been an important factor. It has been a span long enough for a great many species of plants and animals to get here and find a niche and for other species to evolve in the region. The story of the arrival and evolution of the present flora and fauna is intimately linked with the dramatic history of our continent. We can only guess what life existed here during the 130 million years of the Mesozoic era, because no rocks from this period exist in the Smokies. But we can imagine that dinosaurs and primitive birds and mammals roamed the region, as they did other parts of the continent. Toward the close of the Mesozoic, flowering plants evolved and rapidly became the dominant type of vegetation. We can guess that some of these first magnolias, elms, and oaks grew right here in the ancestral Smokies. Newly evolved bees probably helped to pollinate some of the flowering plants.