A "landform" is any physical, recognizable form or feature on the earth's surface that has a characteristic shape and that is produced by natural causes (USDA Natural Resources Conservation Service). Landforms are largely responsible for local variation in solar radiation, soil development, moisture availability, and susceptibility to wind and other disturbance. They therefore have a large influence on plant productivity and species distributions. This dataset maps 17 landforms that are commonly found in the Northeastern U.S. and eastern Canada.

This dataset was developed by The Nature Conservancy as part of "Resilient Sites for Terrestrial Conservation in the Northeast and Mid-Atlantic region" found here: http://www.conservationgateway.org/ConservationByGeography/NorthAmerica/UnitedStates/edc/Documents/TerrestrialResilience020112.pdf

Landform is a compound measure, which can be decomposed into the primary terrain attributes of elevation, slope, aspect, surface curvature, and upslope catchment area. The wide availability and improving of quality of digital elevation data has made the quantification of primary terrain attributes a simple matter. Compound topographic indices have been derived from those primary attributes to model various ecological process. For this dataset, we adopted the Fels and Matson (1997) approach to landform modeling. They described a metric that combines information on slope and landscape position to define topographic units such as ridges, sideslopes, coves, and flats on the landscape. Details on the methods used are provided in Appendix II of the Resilient Sites report cited above.

Using this approach, we mapped the following landforms:
Cliff
Flat summit/ridgetop
Steep slope cooler aspect
Steep slope warmer aspect
Slope crest
Low hilltop flat
Low hill
Sideslope cooler aspect
Sideslope warmer aspect
Cove or footslope cooler aspect
Cove or footslope warmer aspect
Valley/toe slope
Flat at bottom of steep slope
Dry flat
Wet flat
Lake/pond/river
Estuarine/marine