Plant parameters assessed from random quadrat sampling in marsh mesoscosms prior to oiling: June 2018-June 2019

Plant parameters were sampled monthly at the Louisiana Universities Marine Consortium (LUMCON) saltmarsh mesocosm facility in Cocodrie, Louisiana. These twelve hydrologically-isolated, large (~3m diameter) mesocosms were planted with intact Spartina alterniflora and soil sections in January 2018. Each month from June 2018 to June 2019, 5 out of 25 possible central grids were randomly selected to be sampled within each marsh mesocosm. A 0.25m x 0.25 m quadrat was randomly placed within each grid and the following plant parameters were recorded: live stem density (stems/m2), median live stem height (cm; determined from measurements of 5 random stems per quadrat), new growth (stems < 10 cm) stem density (stems/m2), flower density (flowers/m2), and dead stem density (stems/m2). This dataset represents results for the twelve-month period prior to the addition of oil to some of the mesocosms as part of large-scale oiling experiment initiated 2019-07-08.