DOI: 10.5061/dryad.k3j9kd5h9
title: Dataset: Effects of flooding and nutrients on Spartina patens and Sagittaria lancifolia soil shear strength: a greenhouse study

description: This dataset is from a greenhouse study on the effects of flooding and
 nutrient-enrichment on two marsh plant species common to Louisiana. The
 greenhouse study tested the effects of flooding (5, 45, and 90% time
 flooded) and nutrients (control and 2 mgN/L + 0.1 mgP/L) on growth and
 strength of Sporobolus pumilus and Sagittaria lancifolia.
 Sporobolus at higher elevation had higher aboveground biomass and higher
 shear strength than at low elevation. Measurements include above-and
 belowground biomass and soil shear stength.
description: To test the hypothesis that <em>Sporobolus </em>and
 <em>Sagittaria</em> differ in their response to flooding and
 nutrient-enrichment, we conducted a controlled greenhouse
 experiment. Plant material was collected from a
 <em>Sporobolus</em> dominated marsh in Sabine National
 Wildlife Refuge, Calcasieu, Louisiana in the Chenier Plain region of
 Louisiana where large robust stands of<em> Sporobolus</em>
 occur.  <em>Sagittaria </em>plants were collected from an
 intermediate marsh in Barataria Bay. At each site 48 PVC plant plugs of
 each species (15.5 cm diameter and 30 cm deep) were collected and
 transported to the Louisiana State University greenhouses. The plugs
 consisted of 27 clay <em>Sporobolus</em>,19 organic
 <em>Sporobolus</em> and 48 <em>Sagittaria</em>.
 <em>Sporobolus</em> samples were separated later on at
 greenhouse by either clay or organic. Core locations were chosen
 haphazardly to get a random sample of the area. Aboveground biomass in
 each plug were clipped to the soil surface prior to collection.
   Ninety-six plants were placed in one of eight tanks
 each outfitted with a tidal control system (Aquabiotech Inc.)(Figure 13).
 Each tank held 519 liters and was attached to a water reserve carboy that
 holds 1540 liters of water. Water levels were controlled by pumps that
 raised and lowered the water in the tanks over a period of 12 hours (i.e.,
 diurnal tide). Water was pumped at a rate of 760 mL/minute for each tide.
 A split-plot design was used for two levels of nutrients treatment and
 three elevations. Three elevation treatments (low,
 medium, and high) were established for each species within each tank
 (Figure 12)<em>. </em>Six <em>Sporobolus</em> and
 six <em>Sagittaria</em> plugs were placed in each tank with
 two of each species at each elevation treatment. The surface of low
 elevation plugs were 4.6 cm above low water and 33 cm below high water.
 Middle elevation plugs were 19.6 cm above low water and 18 cm below high
 water. High elevation plugs were 34.6 cm above low water and 3 cm below
 high water. The percentage time that the surface was flooded was
 approximately 90, 45, and 5% for low, middle, and high elevations,
 respectively. The location of elevation and species treatments were
 randomized within each tank. These differences in elevation will create
 different percent time flooded for each group with the low elevation group
 having the highest percent time flooded and the high elevation group
 having the lowest percent time flooded.  The nutrient
 treatment (Ambient or Nutrient) was a whole plot factor applied to each
 tank.  Four tanks were filled with tap water (Ambient) and four tanks had
 a single application of fertilizer treatment of 2mg/L of N and 0.1mg/L of
 P (Nutrient). The volume of water in each tank was 519 L. To achieve this
 ratio, 6.49 g of fertilizer with a ratio of 16-0-0 were added and 0.1153 g
 of fertilizer with a ratio of 0-45-0 were added to each tank.
  Average canopy height and stem density by species were collected
 for each of the 96 plugs 3 times over the 293-day study period. At the end
 of the study, shear vane measurements were taken using a Humboldt H-4227
 Vane. This process involves the insertion of a cross-shaped vane into the
 material, followed by the measurement of the necessary torque to shear the
 material by rotating the rod. Three shear vane measurements were collected
 in each plug at depths of 0, 15 and 30 cm.  Above- and
 belowground biomass was harvested at the end of the study. Aboveground
 biomass, was clipped to soil level, separated into live and dead stems by
 species, and dried at 60°C to a constant weight in dry pre-weighed paper
 bags. For belowground biomass, soil plugs were extracted from the PVC and
 cut into three depth segments of 0-10, 10-20, and 20-30 cm. These segments
 were bagged and refrigerated until processed. A 4.5 x 4.0 cm core tube was
 used to collect a soil sample from each depth segment for determination of
 ash weight (loss on ignition; LOI). The core was taken approximately 5 cm
 from the edge of each depth segment. The soil samples were dried to a
 constant weight and placed in a muffler furnace at 550°C for 8 hours. LOI
 was calculated by  . Belowground biomass was measured for each
 depth segment by rinsing the soil through a sieve (0.71mm) and separating
 the live and dead roots. The biomass was then dried at 60°C and
 weighed.
description: # Dataset: Effects of flooding and nutrients on Spartina patens and
 Sagittaria lancifolia soil shear strength: a greenhouse study
 [https://doi.org/10.5061/dryad.k3j9kd5h9](https://doi.org/10.5061/dryad.k3j9kd5h9) ## Description of the data and file structure Specification: [https://creativecommons.org/publicdomain/zero/1.0/](https://creativecommons.org/publicdomain/zero/1.0/); the authors respectfully request to be contacted by researchers interested in the re-use of these data so that the possibility of collaboration can be discussed. Suggested Citation: ``` Quirk, T., N. Matherne, and G. Mariotti. 2024. Data for the article "Dataset: Effects of flooding and nutrients on Spartina patens and Sagittaria lancifolia soil shear strength: a greenhouse study", Dryad, doi.org/10.5061/dryad.k3j9kd5h9 ``` **Contact Information** \* Name: Tracy Quirk \* Affiliations: Department of Oceanography and Coastal Sciences, Louisiana State University \* ORCID ID: [https://orcid.org/0000-0002-2068-592X](https://orcid.org/0000-0002-2068-592X) \* Email: [tquirk@lsu.edu](mailto:tquirk@lsu.edu) \* Alternative Contact: Former M.S. student \* Name: Natalie Martherne \* Affiliations: Department of Oceanography and Coastal Sciences, Louisiana State University \* Email: [natalie.matherne@la.gov](mailto:natalie.matherne@la.gov) **Dates and Locations** \* Dates of greenhouse study: June 2023 to January 2024 \* Geographic locations of plant collections: Barataria Bay, Louisiana: S. lancifolia-dominated marsh (29°40’10.84” N, 90°07’44.07” W), and S. patens marsh in Sabine National Wildlife Refuge (29°52’45.22” N , 93°28’15.84” W) **Methodological Information** \* Greenhouse Treatments: ``` - species: Sagittaria lancifolia, Spartina patens - elevation/flooding: low (-33 cm, MHW), middle (-18 cm, MHW), high (-3 cm, MHW) - nutrients: control, +2 mg/L N and 0.1 mg/L P ``` \* Measurements: canopy height, stem density, aboveground biomass, belowground biomass, soil shear strength **Data and File Overview** Summary Metrics \* File count: 4 \* Total file size: 91 KB \* Range of individual file sizes: 3 - 69 KB \* File formats: .csv Table of Contents * abovegroundbiomassgreenhouse.csv * Belowgroundgreenhouseuse.csv * Ashweightforgreenhouserealuse.csv * Shear strength greenhouse(1).csv ### **File Details** Details for: **abovegroundbiomassgreenhouse.csv** \* Description: a comma-delimited file containing stem density, canopy height and a mactrix of aboveground biomass for all species in grams for Spartina patens and Sagittaria lancifolia subject to flooding and nutrient treatments \* Format(s): .csv \* Size(s): 9 KB \* Dimensions: 98 rows X 29 columns \* Variables: ``` * Species: Spartina patens, Sagitaria * Soil type: n/a, clay, organic * Tank #: 1-8 * Fertilizer: Control (C) or Nutrient (N) * Elevation: low, mid, high (% time that the surface is flooded: 5, 45, and 95) * Height: mean canopy ht (cm) * Stem density: number of stems per pot * S.pat(l): live aboveground biomass of Spartina patens * S.pat(d): dead aboveground biomass of Spartina patens * V.lut(l):live aboveground biomass of Vigna luteola * V.lut(d):dead aboveground biomass of Vigna luteola * S.alt(l):live aboveground biomass of Spartina alterniflora * S.alt(d):dead aboveground biomass of Spartina alterniflora * Sch. sp.(l): live aboveground biomass of Schoenoplectus spp. * Sch. sp.(d):dead aboveground biomass of Schoenoplectus spp. * P.dis(l): live aboveground biomass of Paspalum distichum * P.dis(d):dead aboveground biomass of Paspalum distichum * A.phil(l):live aboveground biomass of Alternathera philoxoroides * A. phil(d):dead aboveground biomass of Alternathera philoxoroides * S.lan(l):live aboveground biomass of Sagittaria lancifolia * S.lan(d):dead aboveground biomass of Sagittaria lancifolia * Juncus sp.(l): live aboveground biomass of Juncus spp. * Juncus sp.(d):dead aboveground biomass of Juncus spp. * P. repens(l): live aboveground biomass of Panicum repens * P. repens(d): dead aboveground biomass of Panicum repens * Cyperus(l):live aboveground biomass of Cyperus spp. * Cyperus(d):dead aboveground biomass of Cyperus spp. * E. aci(l):live aboveground biomass of * E. aci(d):dead aboveground biomass of ``` \* Missing data codes: blank cell Details for: **Belowgroundgreenhouseuse.csv** \* Description: a comma-delimited file containing belowground biomass data in grams for three depth intervals from the greenhouse core samples \* Format(s): .csv \* Size(s): 15 KB \* Dimensions: 272 rows X 10 columns \* Variables: ``` * Sample ID: numeric: 1 - 97 * Species * Soil Type: clay, organic, n/a * Elevation: low, mid, high (% time that the surface is flooded: 5, 45, and 95) * Fert: Control (C), Nutrients (N) * Depth interval (cm): 0-10, 10-20, 20-30 * Mid-point of depth interval (cm): mid-point of depth intervals: 5, 15, 25 * Live biomass (g): dry weight of live biomass in gram * Dead biomass: dry weight of dead biomass in grams * TotalBio: dry weight of live + dead biomass in grams ``` \* Missing data codes: blank cell Details for: **Ashweightforgreenhouserealuse.csv** \* Description: a comma-delimited file containing soil loss-on-ignition (LOI) three depth intervals from the greenhouse core samples \* Format(s): .csv \* Size(s): 16 KB \* Dimensions: 266 rows X 10 columns \* Variables: ``` * Sample ID: numeric: 1 - 97 * Species * Soil Type: clay, organic, n/a * Elevation: low, mid, high (% time that the surface is flooded: 5, 45, and 95) * Fert: Control (C), Nutrients (N) * Depth interval (cm): 0-10, 10-20, 20-30 * Mid-point of depth interval (cm): mid-point of depth intervals: 5, 15, 25 * Wet weight (g): dry weight of soil sample * Dry weight (g): dry weight of soil sample * LOI: the proportion of mass lost on ignition (500 degrees C for 5 hours) ``` \* Missing data codes: blank cell Details for: **Shear strength greenhouse (1).csv** \* Description: a comma-delimited file containing three replicate and then average soil shear strength measurements (pKA) collected using a shear vane at three depths in greenhouse samples \* Format(s): .csv \* Size(s): 14 KB \* Dimensions: 277 rows X 10 columns \* Variables: ``` * Tank: 1- 8 * Species: Sagittaria; Spartina patens * Soil Type: clay, organic, n/a * Elevation: low, mid, high (% time that the surface is flooded: 5, 45, and 95) * Fert: Control (C), Nutrients (N) * Depth (cm): 0 (surface), 10, 20 * Rep 1_shear strength (pKA) * Rep 2_shear strength (pKA) * Rep 3_shear strength (pKA) * Averageshear strength (pKA) ``` \* Missing data codes: blank cell