The Mountain Ecoregions

Abstract

Highland systems are characterized by change more than any other regional system. On the geologic time scale they are subject to rapid changes in topography. Highland areas are associated with the margins of crustal plates, and the great elevations result from the upwarping of the crust along the plate boundaries and the upwelling of magma that forms the volcanic peaks and massive lava flows. These are the zones where volcanic activity is common and where earthquakes may be expected. The high relief, steep slopes, and generally higher precipitation accelerate erosional processes. Mass wasting is a widespread phenomenon in highlands, including avalanches and landslides (Fig. 9.1). It is these relatively high rates of geologic modification by both internal and external forces which give the highlands their rugged aspect.