Crowley's Ridge—Mixed Mesophytic Forests in Northeastern Arkansas

Abstract

Crowley's Ridge is a low, narrow, eroded ridge that rises above the uniformly flat alluvial floodplain in the northeastern quadrat of Arkansas. The ridge is geologically unique because it consists largely of wind-blown soil (loess) deposited during the late Pleistocene. During June 2008, quantitative data on the composition and structure of all strata of forest vegetation were collected from ten 0.1 ha plots at two general localities on the southern portion of Crowley's Ridge. Acer saccharum (sugar maple) was the leading dominant in the large/ medium-sized tree stratum, followed by Quercus rubra (northern red oak), Q. velutina (black oak) and Q. stellata (post oak), all with importance value indices > 10. Other species present included Carya alba (mockernut hickory), Fraxinus americana (white ash), Fagus grandifolia (American beech), and Liriodendron tulipifera (tulip-tree). Except for post oak, these trees tend to be characteristic of the classic Mixed Mesophytic Forest Region of the southeastern United States. In six of the 10 plots, the combined importance values of species typically associated with mixed mesophytic forests represented 84% to 100% of the large/ medium-sized tree stratum. Twenty-three different species were recorded in this stratum, a level of diversity that is comparable to a mixed mesophytic forest. As such, the data presented herein indicate that at least some forests on Crowley's Ridge apparently represent the westernmost examples of this forest type.