Appalachian bogs

[5] Bog ecosystems evolved in humid cold temperate regions and are generally ombrotrophic which means the system is dependent on precipitation for moisture and nutrient inputs.

The sheeting of water keeps the edges of the rock wet without eroding the soil, but in this precarious location no tree or large shrub can maintain a roothold.

[11] Cataract bogs inhabit a narrow, linear zone next to the stream, and are partly shaded by trees and shrubs in the adjacent plant communities.

[11] Sods is a term used in the Allegheny Mountains of eastern West Virginia for a mountaintop meadow or bog, in an area that is otherwise generally forested.

The term is similar (perhaps identical)[citation needed] to that of a "grass bald", a more widespread designation applied throughout the central and southern Appalachian region.