Abstract:

This dataset was developed for assessing and evaluating the productivity of marshes that were impacted by the BP DeepWater Horizon oil spill, thus providing state regulators important information for restoration and management. Physical samples collected include marsh biophysical parameters such as SPAD measured chlorophyll content, vegetation fraction, leaf area index, canopy height and above ground green biomass. Marsh biophysical data were collected in the field using several instruments such as a SPAD chlorophyll meter, LiCOR's LAI 2000 meters, and some destructive sampling for above ground green biomass. This dataset is also registered to the GRIIDC system as dataset Y1.x103.000:0001.

Suggested Citation:

Mishra, Deepak. 2015. Marsh Biophysical data from Northern Gulf Coast Salt Marshes collected from June-October 2011. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7N29VCP

Purpose:

This study intended to allow the identification of ‘hotspots’ of marsh degradation and the extent of recovery (if any) post Deepwater Horizon Oil Spill. The overall goal of the proposed research was to quantify and map the ecological impact of the oil spill on the photosynthetic activity, physiological status, and primarily productivity of the coastal salt marshes to facilitate the prioritization of future restoration actions. The specific questions to be answered through study were: (1) Which wetland patches (location) are most degraded due to the spill? (2) Which salt marsh species is the most vulnerable to the spill? (3) What is the degree of damage and extent of recovery in the spill impacted marsh habitats?

Data Parameters and Units:

Plot = code for plot, code was created using initials from sampling location and replicate number, where CI = Cat Island, MS; MP = Marsh Point, MS; STM = St. Marks, FL; L = Lumcon, LA; IUS = Inverted US Island near Skiff Island, LA; SI = Skiff Island, LA; BJ = Bay Jimmy, LA; and DC = Daniels Cut, LA. Lat = latitude in decimal degrees; long = longitude in decimal degrees; SPAD = in situ leaf level chlorophyll content in milligrams per gram collected using a Minolta 502 SPAD chlorophyll meter; LAI = leaf area index (a ratio of green foliage area vs. ground area); VF (%) = vegetation fraction (percent green canopy cover) ; Biomass (g/sq.ft) = above ground green biomass in grams per square foot; Canopy height = average height of above ground vegetation (centimeters)

Methods:

Minolta 502 SPAD Chlorophyll meter (Spectrum Technologies Inc., East — Plainfield, IL, USA) was used to measure in situ leaf level chlorophyll content. Leaf Area Index (LAI) was measured using LAI Plant Canopy Analyzer 2000 (LICOR Biosciences Inc., Lincoln, NE, USA) Above ground green biomass data were collected from a 0.09 m2 (1 ft2) sub-plot within each study plot using a PVC frame and clippers. The biomass was sorted in order to separate the standing dead from the live biomass; oven dried at 50 °C overnight (~12 h), and the dry weight was recorded using a standard measuring balance. Precautions were taken to avoid moisture absorption by the dried biomass during dry weight measurement as much as possible.

Instruments:

Minolta 502 SPAD Chlorophyll meter (Spectrum Technologies Inc., East — Plainfield, IL, USA) LAI Plant Canopy Analyzer 2000 (LICOR Biosciences Inc., Lincoln, NE, USA).

Individual Files: