Paper No. 214-15
Presentation Time: 9:00 AM-6:30 PM
GROUND-BASED LIDAR DERIVED VEGETATION CHANGES, SEDIMENT DEPOSITION, AND SOIL ORGANIC CARBON RETENTION AT THE BIG SPRING RUN, PENNSYLVANIA, WETLAND RESTORATION SITE
Big Spring Run (BSR), one of many impaired streams in the mid-Atlantic region, is the site of a novel wetland-floodplain restoration experiment with long-term monitoring to test a new Best Management Practice. The study area in southeastern Pennsylvania was impacted by historic valley-bottom sedimentation that buried a Holocene wet meadow with small streams. The restoration tests the hypothesis that removal of historic sediment from the valley bottom and re-connection of ground and surface water across a wetland-floodplain with multiple small channels will result in a decrease in downstream sediment supply (via removal of eroding banks), more frequent overbank flow, greater density of wetland-floodplain vegetation, and an increase in soil organic carbon content and denitrification within the restored wetland-floodplain. This study 1) quantifies post-restoration above-ground vegetation volume using both ground-based LiDAR and a conventional clip method in a study area of 448 m2
; 2) correlates riparian vegetation change with soil organic carbon in sediment deposited since restoration in the fall of 2011; and 3) compares the amount of soil organic carbon with that of the buried Holocene hydric soil and other wetlands. In addition, this study developed a new approach to measure soil organic carbon.
The results of this work show a positive correlation between LiDAR-derived and traditional field-based estimates of vegetation volume. A combination of Loss on Ignition (LOI) and Elemental Combustion Analyzer is the most time/labor efficient and reliable way to differentiate soil organic and inorganic carbon. Overall carbon retention during the first three years since restoration is 0.28 tons within the primary study area (448 m2). Comparison with other wetlands in Pennsylvania shows that the average soil organic carbon at BSR is about 69% of that in the buried hydric soil and 38% of that in a nearby unimpaired Holocene wetland (Great Marsh).