Edaphic Response To Bottomland Hardwood Forest Wetland Restoration In Arkansas.

Bottomland hardwood forest wetlands (BLHFW) provide a myriad of ecosystem services, yet much information is lacking with respect to how soil physical properties and re-established microtopography influence biogeochemical cycling following wetland restoration activities. Recreating hummocks and swales, ± 1 m, has been suggested to be a wetland restoration best practice. Hummocks (30) and swales (30) were contoured throughout a now 12 year old, 149 ha, bottomland hardwood wetland restoration mapped as a Perry Clay (Very-fine, smectitic, thermic Chromic Epiaquerts). We determined soil density and texture throughout the entire site from 135 soil cores at depth intervals 0-30 cm, 30-60 cm, and 60-90 cm, using a randomly placed grid over the tract. Soil density, organic carbon (SOC), and total nitrogen (TN) are also being determined to 15cm depth at randomly selected hummock (10), swale (10), and flat (10) features. Bulk density and silt percentage differ significantly (α=0.05) by depth; however, percent sand and clay do not differ by depth. Preliminary results indicate that SOC and TN do not differ (α=0.05) by topographic feature. SOC appears to respond positively to vegetative cover, flat and hummock locations are colonized considerably denser than swales.  These results provide benchmarks for soil density, SOC, and TN at restored microtopographic features.  These properties SOC and TN are also useful restoration performance metrics.