DOI: 10.7910/dvn/n2jby5
title: What Happens After Phragmites is Killed: A Retrospective Analysis

description: This database contains nine spreadsheets titled: “2011_TMON_All.csv,” “2014_TMON_All.csv,” “2020_TMON_All.csv,” “Historical_Covers.csv,” “Modern_Covers_01.csv,” “Modern_Sommes.csv,” “Modern_Sommes_PresAbs.csv,” “Combined_HistModern.csv,” and “Chi_Comparison.csv.” There are also two R code files titled: “Management_Analysis_Dataverse” and “Monitored_Analysis_Dataverse.” Both R code files were compiled in R version 4.2.1 (2022-06-23 ucrt) -- "Funny-Looking Kid.” Together, the three files “2011_TMON_All.csv,” “2014_TMON_All.csv,” and “2020_TMON_All.csv,” serve as the raw data compiled together in the R code file “Monitored_Analysis_Dataverse” for the Monitored dataset described in the publication. 
Metadata for the included nine spreadsheets is below:

&lt;b&gt;Historical_Covers.csv&lt;/b&gt; - Historical cover classes of the species listed in this dataset were extracted from McCormick and Somes (1982) classification of plant communities in the 1972 Maryland Wetland Maps (https://geodata.md.gov/imap/rest/services/Hydrology/MD_WetlandMaps1972/MapServer). The maps provided codes for the wetland plant communities present at the sites based on interpretation of natural-color stereoscopic aerial photographs. The plant communities were verified by field-sampling.
Column 1 – Site: Unique site-plot identification code
Column 2 – Code: Community code assigned by McCormick and Somes (1982, see citation and access information below)
Column 3 – Dominants: Four-letter codes for dominant species present in the plant communities, per the community codes assigned by McCormick and Somes (1982)
Column 4 – Treatment: Indicates whether plot was under Short-Term or Continuous Management
Columns 5-15: Column names are four-letter species codes for species present at each unique site-plot combination. A value of 1 in a cell indicates that the species was present in McCormick and Somes’ (1982) dataset, and a missing value indicates that the species was not present in the 1982 dataset.

&lt;b&gt;Modern_Covers.csv&lt;/b&gt; - Modern cover classes of species were sampled between September and October 2022 from 32 individual tidal wetland sites where Phragmites australis had been treated using herbicides.
Column 1 – Site: Unique site-plot identification code
Column 2 – Treatment: Indicates whether plot was under Short-Term or Continuous Management
Column 3 – Phrag_Cover: Phragmites australis cover class as defined by the Braun-Blanquet method.
Column 4 – Spp_Rich: Number of species present in the unique site-plot.
Columns 5-37: Column names are four-letter species codes for species present at each unique site-plot combination. The number present in the cell indicates the species’ cover class, as defined by the Braun-Blanquet method (1 = trace, 2 = 1-5%, 3 = 5-25%, 4 = 25-50%, 5 = 50-75%, 6 = 75-100%), in the unique site-plot.

&lt;b&gt;Modern_Somes.csv &lt;/b&gt; - Modern cover classes of species were sampled between September and October 2022 from 32 individual tidal wetland sites where Phragmites australis had been treated using herbicides.
Column 1 – Site: Unique site-plot identification code
Column 2 – Treatment: Indicates whether plot was under Short-Term or Continuous Management
Columns 3-13: Column names are four-letter species codes for species present at each unique site-plot combination. The modern species present are constrained to only the species described in McCormick and Somes’ (1982) community codes. The number present in the cell indicates the species’ cover class, as defined by the Braun-Blanquet method (1 = trace, 2 = 1-5%, 3 = 5-25%, 4 = 25-50%, 5 = 50-75%, 6 = 75-100%), in the unique site-plot.

&lt;b&gt;Modern_Somes_PresAbs.csv&lt;/b&gt; - Modern cover classes of species were sampled between September and October 2022 from 32 individual tidal wetland sites where Phragmites australis had been treated using herbicides.
Column 1 – Site: Unique site-plot identification code
Column 2 – Treatment: Indicates whether plot was under Short-Term or Continuous Management
Columns 3-13: Column names are four-letter species codes for species present at each unique site-plot combination. The modern species present are constrained to only the species described in McCormick and Somes’ (1982) community codes. A value of 1 in a cell indicates that the species was present in the 2022 survey, and a missing value indicates that the species was not present.

&lt;b&gt;Combined_HistModern.csv&lt;/b&gt; - Historical cover classes for the species listed in this dataset were extracted from McCormick and Somes (1982) classification of plant communities in the 1972 Maryland Wetland Maps (https://geodata.md.gov/imap/rest/services/Hydrology/MD_WetlandMaps1972/MapServer). The maps provided codes for the wetland plant communities present at the sites based on interpretation of natural-color stereoscopic aerial photographs. The plant communities were verified by field-sampling. Modern cover classes of species were sampled between September and October 2022 from 32 individual tidal wetland sites where Phragmites australis had been treated using herbicides.
Column 1 – Site: Unique site-plot identification code
Column 2 – Treatment: Indicates whether plot was under Short-Term or Continuous Management
Column 3 – Time: Indicates whether the species present at the unique site-plot are Historical and originate from historical data collected by McCormick and Somes (1982) or Modern, originating from modern species surveys.
Column 4 – Spp_Rich: Number of species present in the unique site-plot.
Columns 5-15: Column names are four-letter species codes for species present at each unique site-plot combination. The modern species present are constrained to only the species described in McCormick and Somes’ (1982) community codes. A value of 1 in a cell indicates that the species was present in McCormick and Somes’ (1982) dataset or in the 2022 survey, and a missing value indicates that the species was not present in the 1982 dataset or absent in the 2022 survey.

&lt;b&gt;Chi_Comparison.csv&lt;/b&gt;
Column 1 – Site: Unique site-plot identification code
Column 2 – Treatment: Indicates whether plot was under Short-Term or Continuous Management
Column 3 – SimDiff: Column indicates whether the unique site-plot’s modern vegetation was determined to be similar to or different from the vegetation described by McCormick and Somes in 1982.

&lt;b&gt;2011_TMON_All.csv&lt;/b&gt; - Plant cover classes were sampled in 2011 prior to herbicide treatments to remove Phragmites australis from six sites in St Mary’s, Calvert, and Anne Arundel counties on the Western Shore and Talbot County on the Eastern Shore of the Chesapeake Bay.
Column 1 – Plot: Unique site-plot identification code
Column 2 – Year: The year the data in the dataset was collected
Column 3 – Estuary: The estuary the unique site-plot is located in.
Column 4 – Treatment: “Native” treatment refers to unique site-plots which are in native marshes which were not invaded by Phragmites australis. The “Spray” treatment refers to unique site-plots which were in marshes which were invaded by Phragmites australis and where the Phragmites australis was treated using herbicide sprays annually between 2011 and 2013. The “No-Spray” treatment refers to unique site-plots which are in marshes which were invaded by Phragmites australis and where the Phragmites australis was not treated using herbicide sprays.
Column 5 – Spp_Rich: Number of species present in the unique site-plot.
Columns 5-44: Column names are four-letter species codes for species present at each unique site-plot combination. The number present in the cell indicates the midpoint of percent cover classes—as defined in the Braun-Blanquet method (1 = trace, 2 = 1-5%, 3 = 5-25%, 4 = 25-50%, 5 = 50-75%, 6 = 75-100%)—of a given species present in a unique site-plot.

&lt;b&gt;2014_TMON_All.csv&lt;/b&gt; - Plant cover classes were sampled in 2014 after cessation of herbicide treatments in 2011, 2012, and 2013 remove Phragmites australis from six sites in St Mary’s, Calvert, and Anne Arundel counties on the Western Shore and Talbot County on the Eastern Shore of the Chesapeake Bay.
Column 1 – Plot: Unique site-plot identification code
Column 2 – Year: The year the data in the dataset was collected.
Column 3 – Estuary: The estuary the unique site-plot is located in.
Column 4 – Treatment: “Native” treatment refers to unique site-plots which are in native marshes which were not invaded by Phragmites australis. The “Spray” treatment refers to unique site-plots which were in marshes which were invaded by Phragmites australis and where the Phragmites australis was treated using herbicide sprays annually between 2011 and 2013. The “No-Spray” treatment refers to unique site-plots which are in marshes which were invaded by Phragmites australis and where the Phragmites australis was not treated using herbicide sprays.
Column 5 – Spp_Rich: Number of species present in the unique site-plot.
Columns 5-55: Column names are four-letter species codes for species present at each unique site-plot combination. The number present in the cell indicates the midpoint of percent cover classes—as defined in the Braun-Blanquet method (1 = trace, 2 = 1-5%, 3 = 5-25%, 4 = 25-50%, 5 = 50-75%, 6 = 75-100%)—of a given species present in a unique site-plot.

&lt;b&gt;2020_TMON_All.csv&lt;/b&gt; - Plant cover classes were sampled in 2020 after cessation of herbicide treatments in 2011, 2012, 2013 to remove Phragmites australis from six sites in St Mary’s, Calvert, and Anne Arundel counties on the Western Shore and Talbot County on the Eastern Shore of the Chesapeake Bay.
Column 1 – Plot: Unique site-plot identification code
Column 2 – Year: The year the data in the dataset was collected.
Column 3 – Estuary: The estuary the unique site-plot is located in.
Column 4 – Treatment: “Native” treatment refers to unique site-plots which are in native marshes which were not invaded by Phragmites australis. The “Spray” treatment refers to unique site-plots which were in marshes which were invaded by Phragmites australis and where the Phragmites australis was treated using herbicide sprays annually between 2011 and 2013. The “No-Spray” treatment refers to unique site-plots which are in marshes which were invaded by Phragmites australis and where the Phragmites australis was not treated using herbicide sprays.
Column 5 – Spp_Rich: Number of species present in the unique site-plot.
Columns 5-38: Column names are four-letter species codes for species present at each unique site-plot combination. The number present in the cell indicates the midpoint of percent cover classes—as defined in the Braun-Blanquet method (1 = trace, 2 = 1-5%, 3 = 5-25%, 4 = 25-50%, 5 = 50-75%, 6 = 75-100%)—of a given species present in a unique site-plot.

&lt;b&gt;Data Sources:&lt;/b&gt;
1972 Maryland Wetland Maps (https://geodata.md.gov/imap/rest/services/Hydrology/MD_WetlandMaps1972/MapServer).
McCormick, J. & Somes, H.A. (1982). "The coastal wetlands of Maryland." (https://repository.library.noaa.gov/view/noaa/1708/noaa_1708_DS1.pdf)

&lt;b&gt;Citations:&lt;/b&gt;
Furman, B. T., Leone, E. H., Bell, S., Durako, M., & Hall, M. (2018). Braun-Blanquet data in ANOVA designs: Comparisons with percent cover and transformations using simulated data. Marine Ecology Progress Series, 597. https://doi.org/10.3354/meps12604 
McCormick, J. & Somes, H.A. (1982). "The coastal wetlands of Maryland."