Edaphic and Vegetative Responses to Forested Wetland Restoration with Created Microtopography in Arkansas

Abstract

In the last three decades a variety of forested wetland restoration best practices have been developed. Microtopography (surface roughness) is a structural characteristic of forested wetlands and it is known to be beneficial to wetland soil characteristics, hydrology, and vegetation colonization during wetland restoration on formerly leveled lands. We evaluated wetland soil properties and vegetation responses to irregularly created Swales, Flats, and Hummocks at a 12 year-old wetland restoration site in southeast Arkansas. Soil and vegetation properties of interest included soil bulk density, soil organic carbon (SOC), total nitrogen (TN), C:N ratios, total plant cover, plant species richness, plant diversity, and wetland indicator status. Unlike similar studies, Swale positions had significantly lower SOC in the upper 15 cm compared to both the Flat and Hummock positions (p < 0.05). Microtopography also had a similar effect on TN in the upper 15 cm of soil (p < 0.05). Microtopography had significant impacts on species richness, total plant cover, and diversity. Flats had significantly higher plant diversity than Hummock areas. Hummock areas had a greater amount of cover than Flats. In total, 26 of 29 plant species observed were classified as facultative and obligate hydrophytes. Soil properties and comparisons to similar forested wetland restorations suggest that at this site after 12 years edaphic responses to created microtopography are limited, whereas vegetation responses are more advanced.