Nitrate Reduction in a Hydrologically Restored Bottomland Hardwood Forest in the Mississippi River Watershed, Northern Louisiana

Soil Science Society of America Journal (SSSAJ)
2016
Nia Hursta, John R. White, and Joseph Baustian
Publisher N/A
Source N/A
Volume / IssueVolume 80 / Number 6
Pages1698 - 1705
Total Pages N/A
Article Link
PDF Link
ISBN N/A
DOI10.2136/sssaj2016.08.0250
Editor(s) N/A
Conference / Book Title N/A
Flag N/A
Tags N/A
Other N/A
Conference Title N/A
Conference Date N/A
Publication Date17-Nov-16
Article Date N/A
GS Citation N/A
AbstractNitrogen loading from the Mississippi River leads to formation of water column hypoxia in the northern Gulf of Mexico every summer. Bottomland hardwood (BLH) forests located within the Mississippi River watershed could play a crucial role in reducing NO3_ loading to the Gulf of Mexico. However, much riverÐfloodplain connectivity has been muted due to building of levees and land conversion for agriculture. Restoring floodplainÐriver connectivity can potentially reduce river NO3_. Mollicy Farms, a 6475-ha BLH site in northern Louisiana, is the largest floodplain reconnection and BLH reforestation project in the Mississippi River Basin. Soil properties, including microbial measures (microbial biomass N, potentially mineralizable N, and _-glucosidase activity) and NO3_ reduction rates were compared with a control site. Nitrate reduction rates in the restored site were 28% lower than in the control site (11.8 ± 3.4 vs. 16.4 ± 8.1 mg N m_2 d_1), with the potential removal of _48.1 Mg of NO3ÐN from the Ouachita River annually. Other soil microbial measures, however, were >50% lower in the restored site compared with the control site, demonstrating that NO3_ reduction has responded more quickly to hydrologic reconnection. Therefore, NO3_ reduction in restored floodplain wetlands may have a relatively more rapid trajectory of recovery, allowing hydrologic reconnection to be an effective tool for enhancing NO3_ reduction in the Lower Mississippi alluvial valley and reducing N flux to the coastal ocean.
Created: 12/14/2017 10:30 AM (ET)
Modified: 12/14/2017 10:30 AM (ET)
“” “”