Key to Natural Communities

A. Occurring as cavities beneath the earth's surface, often with an opening to the surface, characterized by little or no light, no primary producers, and biotic communities of one or two trophic levels that import energy from outside the system. .... Cave

B. Occurring as large depressions caused by the dissolution and collapse of subsurface limestone, dolomite, or gypsum. Bottoms of depressions sometimes filled with water. Exposed limestone vertical walls and large boulders sometimes present. Vegetative composition and structure generally reflect that of surrounding landscape. .... Sinkhole