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<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>M. Kirwan</dc:contributor>
  <dc:contributor>K. J. McGlathery</dc:contributor>
  <dc:contributor>J. C. Zieman</dc:contributor>
  <dc:creator>T. J. Mozdzer</dc:creator>
  <dc:date>2011</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;The smooth cordgrass&amp;nbsp;&lt;/span&gt;&lt;i&gt;Spartina alterniflora&lt;/i&gt;&lt;span&gt;&amp;nbsp;is the foundation species in intertidal salt marshes of the North American Atlantic coast. Depending on its elevation within the marsh,&amp;nbsp;&lt;/span&gt;&lt;i&gt;S. alterniflora&lt;/i&gt;&lt;span&gt;&amp;nbsp;may be submerged for several hours per day. Previous ecosystem-level studies have demonstrated that&amp;nbsp;&lt;/span&gt;&lt;i&gt;S. alterniflora&lt;/i&gt;&lt;span&gt;&amp;nbsp;marshes are a net sink for nitrogen (N), and that removal of N from flooding tidal water can provide enough N to support the aboveground biomass. However, studies have not specifically investigated whether&amp;nbsp;&lt;/span&gt;&lt;i&gt;S. alterniflora&lt;/i&gt;&lt;span&gt;&amp;nbsp;plants assimilate nutrients through their aboveground tissue. We determined&amp;nbsp;&lt;/span&gt;&lt;i&gt;in situ&lt;/i&gt;&lt;span&gt;&amp;nbsp;foliar and stem N uptake kinetics for&amp;nbsp;&lt;/span&gt;&lt;sup&gt;15&lt;/sup&gt;&lt;span&gt;NH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;,&amp;nbsp;&lt;/span&gt;&lt;sup&gt;15&lt;/sup&gt;&lt;span&gt;NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;, and&amp;nbsp;&amp;nbsp;&lt;/span&gt;&lt;sup&gt;15&lt;/sup&gt;&lt;span&gt;N-glycine by artificially flooding plants in a mid-Atlantic salt marsh. To determine the ecological importance of shoot uptake, a model was created to estimate the time of inundation of&amp;nbsp;&lt;/span&gt;&lt;i&gt;S. alterniflora&lt;/i&gt;&lt;span&gt;&amp;nbsp;in 20 cm height intervals during the growing season. Estimates of inundation time, shoot mass, N uptake rates, and N availability from long-term data sets were used to model seasonal shoot N uptake. Rates of aboveground N uptake rates (leaves + stems) were ranked as follows: NH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&amp;gt; glycine &amp;gt; NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;–&lt;/sup&gt;&lt;span&gt;. Our model suggests that shoot N uptake may satisfy up to 15% of the growing season N demand in mid-Atlantic salt marshes, with variation depending on plant elevation and water column N availability. However, in eutrophic estuaries, our model indicates the potential of the plant canopy as a nutrient filter, with shoot uptake contributing 66 to 100% of plant N demand.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.3354/meps09117</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Inter Research Science Publisher</dc:publisher>
  <dc:title>Nitrogen uptake by the shoots of smooth cordgrass Spartina alterniflora</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>