adret

(ecology) The sunny (usually south) face of a mountain featuring high timber and snow lines.

The sunny slope of a hill or valley side. In the Northern Hemisphere adret slopes face south; in the Southern Hemisphere they face north. Adret slopes are warmer because they receive more insolation. This can have important implications for land use; along the Rhine rift valley, for example, the adret slopes are terraced for vines, while the north-facing ubac slopes are largely forested. Similarly, in the Alps, villages are generally located on adret slopes.