Inundation and salinity impacts to above- and belowground productivity in Spartina patens and Spartina alterniflora in the Mississippi River Deltaic Plain: implications for using river diversions as restoration tools

Ecological Engineering
By: , and 

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Abstract

Inundation and salinity directly affect plant productivity and processes that regulate vertical accretion in coastal wetlands, and are expected to increase as sea level continues to rise. In the Mississippi River deltaic plain, river diversions, which are being implemented as ecosystem restoration tools, can also strongly increase inundation in coastal wetlands. We used an in situ mesocosm approach to examine how varying salinity (two levels) and inundation rates (six levels) influenced end-of-season above- and belowground biomass of Spartina patens and Spartina alterniflora during the growing season (March–October) in 2011. Above- and belowground biomass was highest in both species at higher elevations when inundation was minimal, and decreased exponentially with decreased elevation and increased flood duration. This negative biomass response to flooding was more pronounced in S. patens than in S. alterniflora, and S. patens also showed stronger biomass reductions at higher salinities. This salinity effect was absent for belowground biomass in S. alterniflora. These findings suggest that even subtle increases in sea level may lead to substantial reductions in productivity and organic accretion, and also illustrate the importance of considering the inundation tolerance of co-dominant species in receiving areas when utilizing river diversions for delta restoration.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Inundation and salinity impacts to above- and belowground productivity in Spartina patens and Spartina alterniflora in the Mississippi River Deltaic Plain: implications for using river diversions as restoration tools
Series title Ecological Engineering
DOI 10.1016/j.ecoleng.2015.04.035
Volume 81
Year Published 2015
Language English
Publisher Elsevier
Contributing office(s) National Wetlands Research Center
Description 7 p.
First page 133
Last page 139
Time Range Start 2011-03-01
Time Range End 2011-10-31
Country United States
State Louisiana
Other Geospatial Breton Sound, Mississippi River
Online Only (Y/N) N
Additional Online Files (Y/N) N