Hardpan prairies are grasslands found in flat topographies underlain by a clay fragipan (hardpan). These sites have saturated soils and may exhibit ponding during winter and spring because rainwater cannot drain through the impenetrable hardpan, which is often just a few centimeters below the surface. Likewise, during summer and fall dry periods the thin soil layer above the hardpan may become extremely dry. The shallow soils combined with the extreme hydroxeric regime often limits the growth of trees and large shrubs. Historically, these sites were maintained by frequent fire which would have additionally suppressed tree growth in favor of graminoids and herbs.
WESTERN HIGHLAND RIM ECOREGION
- Western Highland Rim Hardpan Prairie