DOI: 10.5061/dryad.zkh1893qc
title: Data from: Suppression of the invasive shrub <em>Rhamnus cathartica</em> using foliar herbicide and herbaceous revegetation depends on canopy openness and the number and timing of interventions

description: Many invasive shrubs re-establish quickly following initial management by
 resprouting vigorously from surviving stems and germinating from remaining
 seeds. Foliar herbicide is commonly used to treat resprouts but may not
 suppress re-invasion in the long-term since a single application is rarely
 comprehensive and many invaders recruit readily from seed. We tested
 whether follow-up foliar herbicide or herbaceous revegetation can suppress
 Rhamnus cathartica (common buckthorn) by creating 28 experimental blocks
 across seven sites in Minnesota, USA. We imposed a factorial combination
 of revegetation seeding (sown in spring 2017 or left to passive
 restoration) using a mix of 32 graminoid and forb species and foliar
 herbicide (fosamine ammonium) application timing (conventional timing –
 applied in fall 2017 and again in 2019 – or delayed timing – applied in
 2019). We measured vegetation height, cover of functional groups, and
 buckthorn stem densities by size class in each of 2017, 2019, and 2021.
 Conventional timing of foliar herbicide initially reduced buckthorn
 density by 77 % and nearly extirpated buckthorn once completed, leaving
 only 0.6 % cover of buckthorn after two applications. Seeding increased
 the efficacy of herbicide such that seeded plots using conventional
 herbicide timing had the lowest cover of buckthorn and greatest amount of
 native vegetation. In delayed herbicide plots, seeding did not effectively
 reduce buckthorn cover or density. Abundance of herbaceous understory
 plants increased with canopy openness, especially with native seed
 addition. Using both repeated application of foliar herbicide and
 revegetation resulted in the lowest cover and density of buckthorn,
 therefore reducing needs for future interventions.
description: # Data from: Suppression of the invasive shrub *Rhamnus cathartica* using
 foliar herbicide and herbaceous revegetation depends on canopy openness
 and the number and timing of interventions Dataset DOI:
 [10.5061/dryad.zkh1893qc](https://doi.org/10.5061/dryad.zkh1893qc) ##
 Description of the data and file structure Metadata for the manuscript:
 Suppression of the invasive shrub *Rhamnus cathartica* using foliar
 herbicide and herbaceous revegetation depends on canopy openness and the
 number and timing of interventions Submitted for publication at Forest
 Ecology and Management This README provides a brief description of the
 files associated with this project, and then for each file, we provide a
 description of each column variable. This archive contains four data
 files. SHEET DESCRIPTIONS Files big_plot_design.csv BigPlot_HerbComp.csv
 BigPlot_Light.csv BigPlot_TransectSurveys.csv VARIABLE DESCRIPTIONS
 big_plot_design - metadata on experimental transects (each row is a
 transect) ``` site - site name (of 7 sites) block_ID - formated as
 site-block, where block names are colors (black, gray, white, blue, red,
 yellow) transect_ID - formatted as site-block-transect, where transect
 names are letters (ex. A,B,C,D) transect_code - unique identifier for each
 experimental transect in the study (T1-T112) transect_width_m - width in
 meters of the experimental transect (either 12 or 24) seeded - was the
 transect seeded (yes or no) herbicide - was the transect treated with
 foliar herbicide in 2019 (yes or no) ``` BigPlot_HerbComp - data for Robel
 method estimation of vegetation height ``` set - sample timing (formatted
 as year_season) date_yyyy_mm_dd - date of sample people - names of
 technicians associated with the sample data site - name of site (7 total
 sites) block - block name within site wh,ere block names are colors
 (black, gray, white, blue, red, yellow) transect - transect name within
 block, where transect names are letters (ex. A,B,C,D) position - location
 of sample quadrat along the transect. Possible positions are 0,5,10,15,or
 20. These represent distance in m from transect origin. robel_1_low -
 Robel pole estimation of minimum vegetation height in decimeters (10th of
 meter) robel_1_high - Robel pole estimation of maximum vegetation height
 robel_2_low - Robel pole estimation of minimum vegetation height from
 different angle as measurement 1 robel_2_high - Robel pole estimation of
 maximum vegetation height from different angle as measurement 1
 woody_percent - visually estimated percent cover of woody vegetation
 within quadrat buckthorn_percent - visually estimated percent cover of
 Rhamnus cathartica within quadrat herbaceous_percent - visually estimated
 percent cover of all herbaceous species within quadrat grass_percent -
 visually estimated percent cover of all graminoid species within quadrat
 forb_percent - visually estimated percent cover of all forb species within
 quadrat block_ID - formated as site-block, where block names are colors
 (black, gray, white, blue, red, yellow) transect_ID - formatted as
 site-block-transect, where transect names are letters (ex. A,B,C,D)
 robel_mean_low - mean of robel_1_low and robel_2_low robel_mean_high -
 mean of robel_1_high and robel_2_high ``` BigPlot_Light ``` set - sample
 timing (formatted as year_season) date_yyyy_mm_dd - date of sample people
 - names of technicians associated with the sample data site - name of site
 (7 total sites) block - block name within site wh,ere block names are
 colors (black, gray, white, blue, red, yellow) transect - transect name
 within block, where transect names are letters (ex. A,B,C,D) position -
 location of sample quadrat along the transect. Possible positions are
 0,5,10,15,or 20. These represent distance in m from transect origin.
 time_hh_mm_24hr - time of day of PAR measurement (ex. 19:40) PAR_ground_1
 - PAR measurement at the ground PAR_ground_2 - second measurement within
 the same quadrat/position of PAR at the ground (in later sample dates)
 PAR_forested - PAR at chest height ~1.3m PAR_open - PAR measured
 simultaneously in a nearby clearing or forest opening instrument_ground -
 make and model of light sensor for PAR_ground instrument_forested - make
 and model of light sensor for PAR_forested instrument_open - make and
 model of light sensor for PAR_open block_ID - formated as site-block,
 where block names are colors (black, gray, white, blue, red, yellow)
 transect_ID - formatted as site-block-transect, where transect names are
 letters (ex. A,B,C,D) ground_standardized - PAR measurement from
 PAR_ground_1 corrected for known calibration differences among instruments
 forested_standardized - PAR measurement from PAR_forested corrected for
 known calibration differences among instruments open_standardized - PAR
 measurement from PAR_open corrected for known calibration differences
 among instruments total_interception_percent - calculated as 1 -
 ground_standardized divided by open_standardized
 canopy_interception_percent - calculated as 1 - forested_standardized
 divided by open standardized understory_interception_percent - calculated
 as 1 - ground_standardized divided by forested_standardized
 understory_interception_percent_min0 - understory_interception_percent
 adjusted so minimum values are equal to zero total_penetration_percent -
 calculated as 100 minus total_interception_percent
 canopy_penetration_percent - calculated as 100 minus
 canopy_interception_percent understory_penetration_percent - calculated as
 100 minus understory_interception_percent total_penetration_percent_ln -
 natural log of total_penetration_percent canopy_penetration_percent_ln -
 natural log of canopy_penetration_percent
 understory_penetration_percent_ln - natural log of
 understory_penetration_percent ``` BigPlot_TransectSurveys ``` set -
 sample timing (formatted as year_season) date_yyyy_mm_dd - date of sample
 people - names of technicians associated with the sample data site - name
 of site (7 total sites) block - block name within site wh,ere block names
 are colors (black, gray, white, blue, red, yellow) transect - transect
 name within block, where transect names are letters (ex. A,B,C,D) position
 - location of sample quadrat along the transect. Possible positions are
 0,5,10,15,or 20. These represent distance in m from transect origin.
 count_germinants - count of buckthorn germinants in the 1 square meter
 sample at that position count_0_20 - count of buckthorn with a height
 lower than 20cm in the 1 square meter sample at that position count_21_50
 - count of buckthorn with a height between 21 and 50cm in the 1 square
 meter sample at that position count_51_100 - count of buckthorn with a
 height between 51 and 100cm in the 1 square meter sample at that position
 count_101_150 - count of buckthorn with a height between 101 and 150cm in
 the 1 square meter sample at that position count_150_plus - count of
 buckthorn taller than 150cm in the 1 square meter sample at that position
 block_ID - formated as site-block, where block names are colors (black,
 gray, white, blue, red, yellow) transect_ID - formatted as
 site-block-transect, where transect names are letters (ex. A,B,C,D)
 Treatment_herbicide - was the transect treated with foliar herbicide in
 2019 (yes or no) Treatment_seeded - was the transect seeded (yes or no)
 ``` Note: in all cases an value of "NA" indicates that the
 corresponding data was not collected in accordance to the expeirmental
 design (i.e. that metric is not applicable in the listed context).