Contrasts of Vegetation, Soils, Microclimates, and Geomorphic Processes between North- and South-Facing Slopes on Green Mountain Near Denver, Colorado

摘要

Although marked contrasts in types of vegetation on hillside with varying slopes and different exposures are common features of most landscapes with moderate to large topographic relief, few studies have been conducted to determine causes of these contrasts. Vegetation species on north-facing slopes near Denver were predominately shrubs, whereas vegetation species on south-facing slopes were nearly all herbaceous. The principal cause for these vegetation contrasts is greater solar radiation on south-facing slopes. Associated with the greater solar radiation on south slopes were higher soil temperatures, greater evaporation, and decreased soil moisture available for plant growth. More periods of freezing and thawing, and larger areas of bare soil resulted in more runoff and erosion on south slopes. These processes are probable causes for south-facing slopes being less steep than the north-facing slopes.