Evaluation of Wetland Characteristics, Features, and Stressors between Agricultural Conservation Easement Program and Natural Wetlands in the Mississippi Alluvial Valley of Arkansas

The Natural Resources Conservation Service under the Agricultural Conservation Easement Program-Wetland Reserve Easements (ACEP-WRE, termed herein ‘easements’) has restored hundreds of thousands of hectares of wetlands in the Mississippi Alluvial Valley. However, little is known about whether restored wetlands regain the physical features of natural wetlands. Using a wetland rapid assessment methodology, the study compared 21 ACEP-WRE easements with five reference wetlands in northeastern Arkansas. Random transects were used to assess 38 hydrologic, habitat, vegetation, and stressor features. Buffer width (average natural-vegetation width around each wetland as ordinal class) was scored to a maximum of 45.72 m, land-use intensity within 305 m, and landscape composition within 5,000 m. Of the 28 features that varied, seven differed significantly (p < 0.05), with two still differing at the Bonferroni-adjusted threshold (p < 0.0018; 0.05/28): sediment-tolerant vegetation occurred at 19 of 21 easements and no reference wetlands, while hummocks, tussocks, and tree mounds were present at all five reference wetlands compared to only three easements (both p < 0.001). Easements and reference wetlands both contained ditches and water-control structures, while invasive herbaceous plants, narrow buffers, and leveed cells without an outlet were more common at easements, and snags were more common at reference wetlands, though neither reached the adjusted significance threshold. Buffer width and land-use intensity did not differ significantly, though easements contained more agriculture (70% vs. 52%) and fewer wetlands (23% vs. 40%) within 5,000 m of the site. The easements exhibited wetland hydrology but lacked the structural features of mature forested wetlands. Future management priorities should address narrow buffer sections, sediment input, microtopography, and the amount of deadwood