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Effect of nutrients and salinity pulses on biomass and growth of Vallisneria americana in lower St Johns River, FL, USA

We determined the interactive effects of nutrient loading and salinity pulsing on Vallisneria americana Michx., the dominant submerged aquatic vegetation species in the lower St Johns River (LSJR), FL, USA, and its associated algal community. Five hundred and ninety 6-inch diameter intact plant plug...

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Autores principales: Boustany, Ronald G., Michot, Thomas C., Moss, Rebecca F.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Royal Society Publishing 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4448805/
https://www.ncbi.nlm.nih.gov/pubmed/26064592
http://dx.doi.org/10.1098/rsos.140053
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author Boustany, Ronald G.
Michot, Thomas C.
Moss, Rebecca F.
author_facet Boustany, Ronald G.
Michot, Thomas C.
Moss, Rebecca F.
author_sort Boustany, Ronald G.
collection PubMed
description We determined the interactive effects of nutrient loading and salinity pulsing on Vallisneria americana Michx., the dominant submerged aquatic vegetation species in the lower St Johns River (LSJR), FL, USA, and its associated algal community. Five hundred and ninety 6-inch diameter intact plant plugs of Vallisneria were collected from the LSJR in March 2003 and transported to US Geological Survey mesocosm facilities in Lafayette, LA, USA. A 3×3 experimental design consisting of three nutrient levels (control, 1/3 control and 3× control) and three salinity pulsing regimes (no pulse, 1-pulse at 18 ppt and 2-pulse at 12 and 18 ppt) was implemented with three replicates per treatment for a total of 27 experimental tanks. Salinity pulsing significantly reduced all measured Vallisneria growth parameters including above- and below-ground biomass, areal productivity and leaf area index. Nutrient levels had little effect on plants subjected to salinity pulses, but in non-salinity pulse treatments we observed higher mean macrophyte biomass in the low-nutrient loading treatments. Macroalgal components (epiphytes and surface algal mats) were not significantly different ( p=0.2998 and p=0.2444, respectively), but water column chlorophyll a (phytoplankton) was significantly higher ( p<0.0001) in all salinity pulse treatments except for the 1-pulse, low-nutrient treatment. A single salinity pulse at 18 ppt resulted in 22% pot mortality and two consecutive pulses of 18 and 12 ppt resulted in an additional 14% mortality. Individual leaves and ramets lost 59.7% and 67.8%, respectively, in the combined salinity pulse treatments. Nutrient loading tends to have a long-term effect on Vallisneria through complex community interactions while salinity pulsing frequency and intensity has an immediate and direct influence on growth and distribution.
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spelling pubmed-44488052015-06-10 Effect of nutrients and salinity pulses on biomass and growth of Vallisneria americana in lower St Johns River, FL, USA Boustany, Ronald G. Michot, Thomas C. Moss, Rebecca F. R Soc Open Sci Biology (Whole Organism) We determined the interactive effects of nutrient loading and salinity pulsing on Vallisneria americana Michx., the dominant submerged aquatic vegetation species in the lower St Johns River (LSJR), FL, USA, and its associated algal community. Five hundred and ninety 6-inch diameter intact plant plugs of Vallisneria were collected from the LSJR in March 2003 and transported to US Geological Survey mesocosm facilities in Lafayette, LA, USA. A 3×3 experimental design consisting of three nutrient levels (control, 1/3 control and 3× control) and three salinity pulsing regimes (no pulse, 1-pulse at 18 ppt and 2-pulse at 12 and 18 ppt) was implemented with three replicates per treatment for a total of 27 experimental tanks. Salinity pulsing significantly reduced all measured Vallisneria growth parameters including above- and below-ground biomass, areal productivity and leaf area index. Nutrient levels had little effect on plants subjected to salinity pulses, but in non-salinity pulse treatments we observed higher mean macrophyte biomass in the low-nutrient loading treatments. Macroalgal components (epiphytes and surface algal mats) were not significantly different ( p=0.2998 and p=0.2444, respectively), but water column chlorophyll a (phytoplankton) was significantly higher ( p<0.0001) in all salinity pulse treatments except for the 1-pulse, low-nutrient treatment. A single salinity pulse at 18 ppt resulted in 22% pot mortality and two consecutive pulses of 18 and 12 ppt resulted in an additional 14% mortality. Individual leaves and ramets lost 59.7% and 67.8%, respectively, in the combined salinity pulse treatments. Nutrient loading tends to have a long-term effect on Vallisneria through complex community interactions while salinity pulsing frequency and intensity has an immediate and direct influence on growth and distribution. The Royal Society Publishing 2015-02-11 /pmc/articles/PMC4448805/ /pubmed/26064592 http://dx.doi.org/10.1098/rsos.140053 Text en © 2015 The Authors. http://creativecommons.org/licenses/by/4.0/ Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.
spellingShingle Biology (Whole Organism)
Boustany, Ronald G.
Michot, Thomas C.
Moss, Rebecca F.
Effect of nutrients and salinity pulses on biomass and growth of Vallisneria americana in lower St Johns River, FL, USA
title Effect of nutrients and salinity pulses on biomass and growth of Vallisneria americana in lower St Johns River, FL, USA
title_full Effect of nutrients and salinity pulses on biomass and growth of Vallisneria americana in lower St Johns River, FL, USA
title_fullStr Effect of nutrients and salinity pulses on biomass and growth of Vallisneria americana in lower St Johns River, FL, USA
title_full_unstemmed Effect of nutrients and salinity pulses on biomass and growth of Vallisneria americana in lower St Johns River, FL, USA
title_short Effect of nutrients and salinity pulses on biomass and growth of Vallisneria americana in lower St Johns River, FL, USA
title_sort effect of nutrients and salinity pulses on biomass and growth of vallisneria americana in lower st johns river, fl, usa
topic Biology (Whole Organism)
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4448805/
https://www.ncbi.nlm.nih.gov/pubmed/26064592
http://dx.doi.org/10.1098/rsos.140053
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