Definition: An isolated hill with steep sides and a small flat top, smaller than mesas and plateaus. Buttes are formed by erosion when a cap of hard rock, usually of volcanic origin, covers a layer of softer rock that is easily worn away. This hard rock avoids erosion while the rock around it wears down.
Definition: An alpine condition is an environmental condition in which the monthly mean temperature is less than 10 degrees Celsius and which occurs at altitudes above the tree line and below the snowline.
