Garlic Mustard Report 2013 - The Aldo Leopold Foundation

Garlic Mustard Report 2013
9/18/2013
Steven Bachleda
Cameron Bushong
Emily Iehl
Dakota Johnson
Lyndsey Mittelstaedt
Leann Wolthusen
Cooper Kohlman
Alanna Koshollek
Land Stewardship Staff
The Aldo Leopold Foundation
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Table of Contents
Introduction .......................................................................................................................................... - 1 Natural History of Alliaria petiolata ...................................................................................................... - 1 Implications ........................................................................................................................................... - 6 Garlic Mustard Control on the Leopold Memorial Reserve ................................................................... - 6 Methods and Materials ........................................................................................................................ - 7 Overview of Treatment Program .......................................................................................................... - 7 Management Units, Transecting, & Control Methods .......................................................................... - 7 Mapping and Data Collection Protocol ................................................................................................. - 9 Levee Road and Areas Outside of Management Units ....................................................................... - 12 Results................................................................................................................................................. - 12 Discussion ........................................................................................................................................... - 15 Overview of 2013 Garlic Mustard Season ........................................................................................... - 15 Changes in protocol regarding maps and mapping ............................................................................ - 19 Analysis of new equipment ................................................................................................................. - 21 Suggestions and potential changes in protocol for 2014 .................................................................... - 21 Notes on Management Units .............................................................................................................. - 23 Appendix A ......................................................................................................................................... - 26 Works Cited ........................................................................................................................................ - 29 -
Photos
Photo 1. Garlic mustard seedlings………………………………………………..………………………………………………………...1
Photo 2. Garlic mustard basal rosettes. ………..............................................................................................2
Photo 3. Garlic mustard flowering stalks…………………………………………………………………………………..…………....2
Photo 4. Garlic mustard flowers………………………………………………………………………………………………………..…...3
Photo 5. A forest understory taken over by garlic mustard……………………………………………………………..……...3
Photo 6. Garlic mustard siliques………………………………………………………………………………………………………….....4
Photo 7. Viable garlic mustard seeds……………………………………………………………………………………………………...4
Photo 8. The 2010 Stewardship crew transecting a unit in the floodplain forest. …………………………..……...8
Photo 9. The 2013 interns transecting a unit with dense vegetation. …………………………………………………....8
Photo 10. A screen shot of our PDA garlic mustard program..…………………………………….……………………....10
Photo 11. A garlic mustard plot classified as “dense”…………….………………………………………………….…….…...11
Photo 12. A garlic mustard plot classified as “scattered”.……………………………………………………………..……...11
Photo 13. A garlic mustard plot classified as “very scattered” ……………………………………………………..….…...11
Photo 14. Stewardship intern Steven Bachleda transects through high water in the floodplain forest....18
Photo 15. A paper map in comparison to the map shown by the PDA garlic mustard program….………...20
Figures
Figure 1. Expansion of a garlic mustard population……………………………..…………………………………………………5
Figure 2. The range of garlic mustard in Wisconsin as of 2011..………………………………..……………………………5
Figure 3. Diagram used to determine population diameter.………………………..……………………….………………11
Figure 4. Timescale of garlic mustard management at ALF from 2003 through 2013…………………..…….…12
Figure 5. Percentage of plots within each diameter size class.……………………………………………………..………13
Figure 6. Total number of acres occupied by garlic mustard populations from 2003 to 2013.………………13
Figure 7. Yearly totals of gallons of bagged plants and gallons of herbicide used from 2003 to 2013…..15
Tables
Table 1. Hours spent in each management unit during initial visits and revisits in 2013.………………………14
Table 2. Chemical Control (Initial Visits) of Garlic Mustard by ALF Land Stewardship crew and
volunteers, LMR, Spring 2013…………………………………………………………………………………………………………..……26
Table 3. Revisiting Garlic Mustard Populations by ALF staff, LMR, 2013.…………………..………………………....27
Table 4. Total garlic mustard removal by ALF staff and volunteers, 2003-2013…………………………………….28
Table 5. Number of garlic mustard populations and total acres.…………………………………………..………………28
Introduction
Garlic mustard (Alliaria petiolata) is a severely aggressive invasive weed that has spread quickly
through North American forests since its introduction to the United States in 1868. Since it was
first discovered on Long Island, New York, this member of the mustard family (Brassicaceae) has
migrated to 37 states in the U.S. and five provinces in Canada (Munger 2001, USDA 2013).
Supposedly cultivated for its use in cooking and medicine by early American settlers, garlic
mustard now invades a variety of ecosystems, including those on the Leopold Memorial
Reserve. This year, the 2013 Land Stewardship Interns continued to monitor and treat
populations of garlic mustard on 300 acres of the Reserve.
Natural History of Alliaria petiolata
Garlic mustard is an obligate biennial herb, which means that the plant has a two-year life cycle.
According to Nuzzo (2000), the life cycle starts when a seed germinates and the seedling plant
(Photo 1) emerges in early spring. Although germination often occurs well before the
appearance of native spring ephemerals, new seedlings have been observed by the Aldo
Leopold Foundation Stewardship Crew throughout the entire growing season. This means that
seeds do not have a very limited window in which to germinate—they may sprout at any time
during the summer.
Photo 1. Garlic mustard seedlings. Note the bright green color, delicate form, and clear
scalloping on margins of leaves. Seedlings may grow as a single plant or in carpets, as shown in
the photo.
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During its first year, garlic mustard germinates as a seedling and then transforms into a basal
rosette. The leaves of the rosette are dark green and kidney-shaped with scalloped edges, 6-10
centimeters in diameter (Photo 2). The plant does not produce seeds in the first year and will lie
dormant as a rosette through the winter months. Basal rosettes can be managed with chemical
treatment or by hand pulling, but first year plants are less of a priority for control than second
year plants.
www.eddmaps.org
msue.anr.msu.edu
Photo 2. Garlic mustard basal rosettes. The leaves on this life stage are larger,
rounder, darker green color, and have deeper venation. Multiple stems grow from
one root system.
In its second growing season, garlic mustard rosettes reemerge and produce flowering stalks
that reach 2-4 feet in height (Photo 3). Manual or chemical control is imperative before these
stalks go to seed. Second year plants often produce more than one flowering stem from a single
basal rosette, with some single plants producing up to 12 separate stems that continue to grow
throughout the summer. White, cross-shaped flowers typically bloom 6-10 weeks after plants
come out of dormancy (Photo 4). Pollination occurs as long as flowers bloom.
Photo 3. Garlic mustard flowering
stalks. The architecture of the
mature plant is taller and more
linear than the basal rosette, but
multiple stalks may still spring
from one root system. The leaves
are triangular in shape with sawlike teeth. You may encounter
mature garlic mustard plants
singly or in clumps and with or
without flowers.
wisconsin.sierraclub.org
mda.state.mn.us
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The Virtual Nature Trail at Penn State New Kensington (2013) describes the different methods
of garlic mustard pollination and their implications as follows:
“The flowers of garlic mustard are either pollinated quite non-specifically by a variety of insects (solitary
bees, a variety of flies, and on rare occasions, honeybees or bumblebees) or they can self-pollinate if these
insect interactions do not occur. The seeds of the pollinated plants have been shown to be more vigorous
than those produced by the self-pollinated plants. The ability to self-pollinate, though, does confer a great
advantage on the survivability of an invading population founded by a single, established individual. Garlic
mustard also has a slender, white taproot from which adventitious buds that can form flower stalks can
arise. This root budding ability further adds to the difficulty of population control of these invasive plants.”
The opportunistic reproduction of garlic mustard contributes heavily to its ability to invade new
territory (Photo 5). All of these reproductive strategies must be taken into consideration when
managing the species.
ecga.org
Photo 4. Garlic mustard flowers. Flowers are small,
white, and have four petals. A single stalk produces
many flowers.
beyondturf.com
Photo 5. The opportunistic reproduction of garlic mustard
allows the species to take over entire forest understories
and other niches in different communities.
At the Aldo Leopold Foundation, the most efficient strategy to manage garlic mustard
populations is to prevent the majority of seeds from replenishing the seed bank.
After pollination, garlic mustard flowers produce green siliques that contain maturing seeds
(Photo 6).The number of seeds produced by each plant can vary from a few hundred seeds up
to 7,900 seeds or more from a large, multi-stemmed plant. When the seeds have matured and
become viable, the siliques burst open and drop the seeds to the ground (Photo 7). The seeds
remain dormant until 50 to 105 days of cold stratification trigger the seed to germinate. If not
subjected to an adequate cold period, the seeds may remain viable in the seed bank for five
years or more, germinating only when conditions are conducive to the success of the plant (PSU
New Kensington Virtual Nature Trail 2006).
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florafinder.com
Photo 6. Garlic mustard siliques,
which form after pollination and
contain maturing seeds.
countrycrone.com
Photo 7. Viable garlic mustard seeds. When the seeds mature, the siliques
stop growing, turn brown, and split open to release the seeds.
The seeds’ capacity to stay viable for many years contributes to the spread of garlic mustard
across the continent. They can be transported through a number of possible vectors in their five
year lifespan and can take root in places far from the parent plant. Most commonly, garlic
mustard seeds are picked up and transported by animal feet and fur. The treads of shoes and
tires also prove effective in the spread of garlic mustard, especially by off-trail hikers and
roadside mowers. Flash floods or runoff from a rainstorm can lift the seeds and carry them with
the current to new locations. However, in slow or standing water, the shape and weight of the
seed usually causes seeds to sink instead of float, which inhibits much other water-based
transportation. Similarly, although transportation by wind cannot be ruled out, the physical
shape of garlic mustard seeds is not particularly aerodynamic. Figure 1 depicts the aggressive
regeneration of a single garlic mustard plant by seed. Combined with the easy transport of
seeds by people and animals, even a couple years of no treatment can contribute to significant
increases in population sizes and time required to get control of the species.
Other innate characteristics of garlic mustard also contribute to its aggressiveness as an
invasive species. Ironically, some of these characteristics may have played a role in the plant’s
appeal to humans as a culinary and medicinal aid. For example, the plant’s garlic taste and
smell often repel North American predators. Even white-tailed deer avoid the plant, preferring
to graze upon better-tasting native species. The plant also produces antifungal chemicals that
secrete into the soil and, on this continent, “disrupt associations between mycorrhizal fungi and
native plants, suppressing native plant growth” (WDNR 2013). The suppression of native plant
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growth contributes significantly to the destabilization of any ecosystem; including those that
garlic mustard invades in North America.
Single seedling
Year 2
Year 3
Year 4
Year 5
Year 6
Figure 1. Expansion of a garlic mustard population. In year 1 a single seed germinates and a garlic mustard plant
begins its life cycle. In year 2, the single plant matures and disperses seed. In year 3, seeds from the parent plant
germinate, multiple basal rosettes are produced, and a population is formed at .5m-1m. In year 4, the basal
rosettes mature and disperse seed, extending the population to >2m with both first and second year plants. In
year 5, both first and second year plants are present. If left unchecked, the population will begin to exponentially
grow from this point forward, while adding thousands of seeds to the seed bank. This scenario creates a
population which will need to be managed for at least 7 years. If the population is detected prior to year 4,
management efforts will be decreased.
Originally native to northern Eurasia from England to
the western edge of the former Soviet Union, garlic
mustard can now be found in forests and forest edge
habitats, along roadsides and stream banks, and in
disturbed and urban areas of North America. Garlic
mustard is found in many locations throughout
southern and central Wisconsin (Figure 2). It is
possible that there are additional unrecorded areas in
the state where garlic mustard grows.
dnr.wi.gov
Common communities in which it can be found
Figure 2. The range of garlic mustard in
include oak savannas, prairies, and both floodplain
and upland forest. It is rarely found in pine-dominated Wisconsin as of 2011. The only counties with
no records of the plant are Bayfield, Washburn,
ecosystems, but the plant will eagerly colonize areas
Eau Claire, Menominee, and Shawano counties.
where conifers exist in less abundance (Munger
2001). Garlic mustard will also tolerate most soil types from sand to clay, but cannot tolerate
very acidic soils, such as peat. In addition to its ability to adapt to a variety of soils, the plant
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does well in a wide range of light. It can be found in partial shade to full sun, although it seems
to do best with half shade. These conditions can be found readily on the Leopold Memorial
Reserve, where Aldo Leopold Foundation Staff first started controlling garlic mustard 18 years
ago.
Implications
Outside of its native range, garlic mustard has spread quickly and relatively unchecked.
Although efforts to educate the public about the transport and impact of this weed in state
parks, state natural areas, and privately-owned land abound, new populations of garlic mustard
continue to become established in previously uninfected areas at an alarming rate. Due to its
numerous opportunistic reproductive strategies, populations that are neglected for even one
season can add a significant number of seeds to the local seed bank, requiring that monitoring
and treatment continue for many more years.
In most cases, federal and state governments cannot take an active approach to managing
garlic mustard due to its aggressive nature. Staff members of the Wisconsin Department of
Natural Resources, who manage public land near the Aldo Leopold Legacy Center, explain that
the personnel requirements and funding to control garlic mustard are unavailable to large
management areas. Without these resources, combating garlic mustard is impossible.
In effort to overcome deficiencies in staff and funding, some research has been conducted
about the possibility of releasing a European weevil as a biological control (Blossey et al 2001).
In Europe, 70 known species of insects and seven species of fungi prey upon different parts of
Alliaria petiolata and keep populations in check. However, in the 20 years that this research has
been continuing, no plan of action has yet been implemented for the release of the weevil into
the United States or Canada, and garlic mustard continues to spread.
Garlic Mustard Control on the Leopold Memorial Reserve
In an effort to preserve and restore the integrity of native ecosystems on land owned by the
Aldo Leopold Foundation, 18 generations of ALF Land Stewardship interns have developed an
intensive approach to garlic mustard control.
In 1996, interns started spraying and hand pulling garlic mustard around the Shack and other
prominent areas of the Leopold Memorial Reserve. Each year, these areas of known garlic
mustard populations grew in number and control efforts expanded across the LMR. In 1999, a
tract of land called the Potter Preserve was donated to the Foundation and areas of this
property were also incorporated into the initial stages of garlic mustard control. Interns used
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early GPS technology to record the locations of populations and some flags were laid down to
aid in the search for these known populations.
It wasn’t until 2004 that garlic mustard treatment was extended into the floodplain forest, west
of the Leopold Shack, which is now part of the 300 acres of the core management area on the
LMR. Interns that year for the first time numbered and flagged each population they treated.
Positions of the plots were recorded with GPS so that succeeding interns could retrace their
footsteps and monitor the same populations year after year. After the Leopold Foundation
decided to sell the Potter Preserve in 2009, the Stewardship Crew began an even more rigorous
transecting and scouting effort of the LMR and since then treatment includes transecting all
300 acres.
Through 10 years of data collection, the Leopold Foundation and other land managers can more
clearly see the long-term effects of one of the biggest projects tackled by Land Stewardship
interns each year. The protocol continues to evolve as changes in the garlic mustard
populations occur in response to treatment, and this continuing work on the LMR is evidence
that implementing a long term program for managing garlic mustard can be effective.
Methods and Materials
Overview of Treatment Program
The management of garlic mustard at ALF is divided into two separate stages: initial visits and
revisits. During initial visits, the Stewardship Crew transects through all 300 acres of the core
management area of the Leopold Memorial Reserve and chemically treats all populations of
garlic mustard. After initial visits, we re-transect all 300 acres and revisit each and every
population to ensure thorough treatment. At the time of revisits in mid-June, garlic mustard is
too far advanced in seed production to chemically treat and must be pulled by hand.
All identified populations of garlic mustard on ALF property are marked with bright orange
irrigation flags so that they can easily be located. Populations are given an identification
number, which is written on the flag. The crew methodically covers all designated management
units, transecting and searching for the previously made flags while simultaneously scouting for
new populations. We also collect and record data for all populations so that their characteristics
can be monitored over time.
Management Units, Transecting, & Control Methods
There are currently 15 designated management units for garlic mustard on the Leopold
Memorial Reserve. Units vary in size and have been divided based on features of the landscape
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for ease of treatment. Because certain constraints within the Stewardship Program prevent
planning for an exact starting date for garlic mustard, Stewardship Crews traditionally work
from areas with quality spring ephemeral vegetation to areas with less diverse vegetation to
reduce the impacts of herbicide on non-target plants. Visuals of units and their locations, along
with the average weekly progression for each unit, can be found in Appendix A on the map
entitled Average Weekly Progression for Garlic Mustard.
Crew members transect the entire area within each unit during initial visits and revisits to find
new and existing populations. To transect, two to six crew members line up 5-10 feet apart
from each other at one edge of the unit. The crew walks in a straight line (each crew member’s
line parallel to the person next to him/her) to another side of the unit (Photo 8). Spacing
between crew members depends on the density of vegetation; generally, more dense areas
require crew members to be closer together as the line of sight is limited (Photo 9). The crew
members on the outside edges of the transect are in charge of laying down pink flags to mark
the extent of the transect. When the crew reaches their end boundary, they turn around about
the flag line that was laid down by one outside crew member and walk back to the opposite
boundary following the flag line along the way. The person who initially laid these flags down
picks them up on the way back and the other person on the outside lays the new flag line,
which marks the new transect border. This process is efficient and effective at finding existing
populations, although it can often be time consuming.
Photo 8. The 2010 Stewardship crew transecting a
unit in the floodplain forest. The interns walk from
one unit boundary to another in parallel lines 5-10
feet apart. In clear areas, like this meadow,
crewmembers can increase the space between each
other to cover more ground.
Photo 9. The 2013 interns transecting a unit with dense
vegetation. Since visibility is limited, crewmembers need
to walk closer together in order to see each other and
any garlic mustard that might be between them.
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Upon encountering flagged or new populations of garlic mustard, first and second year plants
are sprayed with a 1.5 - 2% RazorPro (glyphosate) and water solution. Tracer, a red foam dye, is
also added to the solution to help increase visibility of sprayed areas. RazorPro takes at least a
week to work before there is a visible result on the sprayed area. However, it only takes the
chemical an hour to dry on the leaves of sprayed plants, at which point we can be confident
that it will effectively kill the plant. We use 4-gallon Solo piston backpack sprayers outfitted
with light-mist nozzles for all chemical application. We also transport large batches of mixed
chemical to the field in a 35-gallon sprayer tank on the back of the Kubota, from which we can
refill our backpack sprayers as needed.
Since the chemical does not break down quickly after mixing, large batches of chemical can be
made and stored for use throughout the week. To make a 1.5 - 2% Razor Pro solution in
volumes equal to or less than 25 gallons, we mix 2 oz. of Razor Pro for each gallon of water (for
example, to make 25 gallons of mixed chemical, combine 50 oz. of Razor Pro and 25 gallons of
water). For volumes over 25 gallons, we mix 1.75 oz. Razor Pro per gallon. Other brands of
glyphosate, such as Roundup, may require different mixing ratios of chemical to water, so be
sure to check the label on your container. The manufacturer of Razor Pro also notes that
“colorants or dyes used in spray solutions of this product may reduce performance, especially
at lower rates or dilutions” (Razor Pro 2013). Be sure to check labels and instructions on
anything you may add to your chemical mixture. It may also be helpful to write down your
observations and fine-tune chemical treatment methods as you see results.
Following the initial visits, all populations are visited a second time to hand-pull plants that
were overlooked during initial visits. Garlic mustard has a slender, white, S-shaped taproot,
which makes hand-pulling a fairly easy task in sandy soils. However, in richer or compacted
soils, the plant can easily break off with the root remaining in the soil to produce another seedbearing plant. When hand-pulling, effort should made to pull the entire plant including the
entire root to prevent re-growth. Garlic mustard seeds have the ability to continue to mature
on the pulled plant, so any plant pulled is bagged and removed from the site.
In addition to hand pulling, all bright orange irrigation flags need to be replaced during revisits.
Crew members carry new flags and write the plot identification number and diameter on the
flag with Sharpie chisel-tip markers. Flags need to be replaced yearly as weathering makes
reading the information on the flag difficult.
Mapping and Data Collection Protocol
The mapping and data collection of the 2013 garlic mustard season was conducted according to
protocol outlined in 2009. Each newfound population of garlic mustard is flagged with a bright
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orange irrigation flag and numbered. We use a Personal Digital Assistant (PDA) with a Bluetooth
GPS function to mark the plot location. The PDA contains an ArcGIS map of all the garlic
mustard populations mapped from previous years. This allows crews to navigate to mapped
populations, map new populations, and record the appropriate data for each point. The PDA
also allows us to move previous GPS points that appear to be in the wrong location.
After a day in the field, the PDA is connected to the
computer and our data gets backed-up by ArcPad that
extracts the field data. The software updates the ArcGIS
maps with any new points that were created and also
indicates which points have been treated and which have
not. When a garlic mustard flag is found by the crew, the
person who found it communicates the information on
the flag to the rest of the crew. This information includes
the plot identification number and the diameter of the
population. The diameter that is written on the flag is the
largest historical diameter of the population. All other
crewmembers mark the identification number off of their
field maps to indicate that the point has been visited. The
crew member then walks and searches the entire area of
the plot to determine if any garlic mustard is present and
at what density. The PDA operator records the date of the
visit, diameter of the population in meters, density of
garlic mustard within the plot, number of dead stems
present, and the method of treatment (Photo 10).
Photo 10. A screen shot of the data
collection page in our PDA garlic mustard
program. For each plot, we list the date it
was visited, the density and diameter of
the population, how it was treated, and
whether any dead stems were present.
New points are created when unmapped populations of garlic mustard are discovered in the
field during transecting. Prior to flagging and marking a new population with the PDA, it should
be determined that the observed plants are not included within the diameter of a large, nearby
population. If it seems that the plants are beyond the diameter of nearby populations and
distinctly separated by native vegetation, it is safe to assume that it is a new population that
should be flagged and mapped. If the potential new population is outside of the largest
recorded diameter of a nearby plot, but not separated by native vegetation, one should
consider widening the diameter of the already existing population. Edge flags are useful when
the diameter of a plot is so wide that it is difficult to find the boundary with the naked eye.
When these situations occur it is helpful to flag the north, south, east and west boundaries.
Due to the fact that not all of the populations are perfect circles, we have considered the
“diameter” to equal the longest axis of the population. Many populations are very linear in
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shape, especially when infestations follow wildlife trails and established pathways, which
means the recorded diameter—the longest axis—can be very large compared to the width of
the population (Figure 3). The diameter of any plot varies from year to year and is adjusted by
the Stewardship Crew if necessary.
Longest Axis
Figure 3. Diagram used to determine population diameter.
The density of populations is also recorded in the PDA program and has been standardized to
include three categories: “dense,” “scattered,” and “very scattered.” To be considered dense,
80-100% of the ground in the plot must be covered by garlic mustard, and the majority of garlic
mustard plants touch each other on at least three sides. To be considered scattered, 21-79% of
the ground is covered by garlic mustard, and the majority of plants touch two other plants. To
be recorded as very scattered, 20% or less of the ground is covered by garlic mustard, and the
majority of plants do not touch one another. These densities are shown in Photos 11, 12 and 13
respectively. Recording how many plants occupy a set amount of space gives us another
criterion to evaluate the extent of the garlic mustard infestation on the LMR. We hope for plots
to be very scattered instead of densely packed full of seed-producing plants.
Photo 11. A garlic mustard plot
classified as “dense.”
Photo 12. A garlic mustard plot
classified as “scattered.”
Photo 13. A garlic mustard plot
classified as “very scattered.”
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Levee Road and Areas Outside of Management Units
Populations of garlic mustard exist in areas that are not managed using the preceding protocol.
This year, the Aldo Leopold Foundation worked with the neighboring Sand County Foundation
(SCF) to chemically treat populations occurring along Levee Road from Schepp to County
Highway T. During this treatment, two people wearing backpack sprayers walked down both
sides of Levee Road and sprayed all garlic mustard within 10-15 feet of the roadside.
Several areas within the Terbilcox property were also treated without transecting near the Van
Hoosen house and along the trails south of the Legacy Center. These areas were sprayed using
a 200-gallon gas-powered sprayer mounted on the back of the F-350 Super duty dually. Using
low pressure, we sprayed as far into the properties as we could drag our 150-foot hose. No
data about specific populations was collected for these areas and they were not flagged. Only
work hours and gallons sprayed were recorded.
Results
Management of garlic mustard in 2013 began May 10 and ended July 10. Initial visits lasted
from May 10 until June 14 and revisits started June 17 and were finished on July 10. There were
a combined total of 39 work days this season; 24 during initial visits and 15 during revisits.
However, the crew spent five hours or less in the field on 16 of the 39 work days. The timescale
of treatment is displayed in Figure 4.
Timescale of Inital Visits and Revisits
Initial Visits
Revisits
2013
Year
2011
2009
2007
2005
2003
100
04/10
04/10
120
04/30
04/3
140
05/20
160
06/09
Date (mm/dd)
180
06/29
200
07/19
220
08/08
Figure 4. Timescale of garlic mustard management at ALF from 2003 through 2013.
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There are currently 2875 garlic mustard points recorded in the GIS system. 737 of these points
are in the Potter Preserve, which is no longer managed using the protocol outlined in this
report. 2012 of the remaining 2138 points were visited this year, which means 126 points were
not found this year. New population identification numbers this year began with plot ID 2703.
There were 120 new populations found, and the last plot ID assigned was 2817.
This season the average plot size
was 4.12 meters; the median size
Plot Size Distribution (meters)
was 3 meters; the maximum and
2%
minimum sizes were 42 meters and
4%
14%
0m
0 meters respectively (Figure 5). Of
18%
.01 - 1 m
the 265 acres that we manage
15%
1.1 - 5.0 m
garlic mustard on at the Aldo
5.1 - 10.0 m
Leopold Foundation (excluding
10.1 - 15.0 m
roadsides), garlic mustard plots
47%
occupy 14.5 acres as of 2013
> 15.0 m
(Figure 6). 92% of those 14.5 acres
are characterized as having very
Figure 5. Percentage of plots within each diameter size class.
scattered densities of garlic
mustard. Only 16 dead stems of garlic mustard plants were found this year, theoretically
meaning that last year’s crew missed only 16 plants during treatment. During initial visits,
chemical treatment occurred at 85% of all plots, no treatment occurred at 14% of all plots
(usually because no garlic mustard plants were visible), and less than 1% of the plots were
manually treated.
Total Acres of Alliaria petiolata
*Includes the Potter Property Until 2009
Number of Acres
20
15
10
5
5.4
0 0
2003
2004
8.0
11.0
10.4
11.2
12.4
14.2
13.3
14.5
2007
2008
2009
2010
2011
2012
2013
3.1
2005
2006
Year
Figure 6. Total number of acres occupied by garlic mustard populations from 2003 to 2013.
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During the 2013 season, the Stewardship Crew spent a total of 788 hours managing garlic
mustard on the 15 core management units on the LMR (Table 1). We spent an additional 59.25
hours spraying SCF roadside and Terbilcox property with the gas-powered sprayer for a grand
total of 847.25 hours of garlic mustard management. There were usually 3-5 crew members
working in the field every day. This is the largest number of person hours spent on treatment in
the history of garlic mustard management. During these hours, the crew sprayed 330 gallons of
herbicide over the 25 days of initial visits. Additionally, ALF staff sprayed 420 gallons of
herbicide with the gas-powered sprayer on unflagged roadside populations and areas on the
Terbilcox property. Throughout the 15 days of revisits, the crew pulled and bagged 553 gallons
of garlic mustard (Figure 7).
Management Unit
Initial Hours
Revisit Hours
Charlie’s Woods
53.5
73.25
Shack Pines
17.25
7
Orchard
4.5
1
Anniversary Unit
5.5
5
Shack Foundation
6
5
Sandhill
16.25
8.75
South of Birch Row
12.5
10
North Birch Row
30.5
15
Floodplain between Eddy Gordon and Levee
80.25
53
Lower Floodplain between Eddy Gordon and River Trail
119.5
64
Upper Floodplain between Eddy Gordon and River Trail
80
24.25
North of the River Trail
9
2.25
North of the Sands
9.25
4.5
West of Suevanna
Clay Hill
9
39.5
6.75
15.75
492.5
295.5
Total
Table 1. Hours spent in each management unit during initial visits and revisits in 2013.
- 14 -
Gallons of Bagged Alliaria petiolata and Gallons
of Herbicide Sprayed
1200
Gallons
1000
800
600
Bagged Gallons
400
Gallons of Herbicide
200
0
2005
2006
2007
2008
2009
2010
2011
2012
2013
Year
Figure 7. Yearly totals of gallons of bagged plants and gallons of herbicide used from 2003 to 2013.
Discussion
The ALF 2013 garlic mustard season proved to be just as extensive and strenuous as previous
seasons, but in some different ways. This year, the crew adapted management in response to
recommendations by last year’s interns and as a result of unforeseen record-breaking amounts
of rain. New tools and strategies contributed to the effectiveness of our control methods and
have resulted in some revisions to the garlic mustard treatment protocol.
Overview of 2013 Garlic Mustard Season
This year, the Stewardship Crew spent a record 788 person hours treating 14.5 acres of garlic
mustard, which is the largest acreage of garlic mustard ever recorded on the Leopold Memorial
Reserve. The crew also used 330 gallons of chemical in this treatment, which is a volume
second only to the 2011 Stewardship crew’s highest number of gallons sprayed in a season. To
account for these simultaneous expansions in time, resources, and area covered on the LMR
treating garlic mustard, a number of factors unique to the 2013 season should be taken into
consideration.
Acreages of garlic mustard on the Reserve have both risen and fallen in the past few years of
treatment. The 2011 Stewardship interns treated 14.2 acres of garlic mustard plots, more than
any other Stewardship Crew in the project’s history. In 2012, this number fell to 13.3 acres,
which marked the first decrease in treated acres of garlic mustard since 2008. The 2012
Stewardship Crew hoped to attribute this decline to the Aldo Leopold Foundation’s long term
- 15 -
treatment program. However, this year’s data suggests that weather probably played a major
role in the flux of the past couple years of garlic mustard populations.
Local news sources cite June 2013 as the fourth wettest June in 145 years of records taken by
the National Weather Service. The Cap Times also labels 2013 as “the anti-2012” in terms of
temperatures and precipitation (Milewski 2013). These observations extend to the Aldo
Leopold Foundation. Last year, drought affected most plant communities in southern
Wisconsin. The growing season started earlier than normal, causing the 2012 Stewardship Crew
to start treating garlic mustard on April 22, almost a month earlier than the 2011 and 2013
Crews, who started on May 11 and 10, respectively.
Lack of rain and high temperatures likely contributed to the fewer acres of garlic mustard
treated in 2012. Second year intern Leann Wolthusen reports observations of heat stress in
populations of garlic mustard by the end of initial visits last year, which concluded on May 24.
She also notes that a fungus was present in many populations and probably further stressed the
plants, causing below-average growth and seed production. Even native prairie plants produced
fewer flowers and seeds in response to severe temperatures, with some even failing to reach
normal heights.
This year, we postulate that high levels of rain and cooler temperatures brought garlic mustard
back in full force, or perhaps even more vigorously than in “average” years. We have observed
that almost all vegetation is considerably more lush this year than the past few years, despite
the long winter that postponed spring until the very end of April. It is worth proposing that
more garlic mustard seeds than average might have germinated this year as a result of the
favorable conditions in 2013, especially following last year’s particularly unfavorable weather.
In addition, plenty of rain throughout April and June might have given the plants enough
resources to flower and produce seeds longer than usual. As of August 21, we continue to see
the occasional garlic mustard plant in flower. The reaction of plants to higher levels of rain and
cooler weather in 2013 likely contributed to the increase in treated acreage of garlic mustard
on the Leopold Memorial Reserve.
An interesting occurrence that is likely also a consequence of wet conditions are observations
of garlic mustard plants that we lightheartedly label as “zombie GM.” These are plants that
have been sprayed with glyphosate solution during initial visits, appear to have been affected
to an extent by the chemical, but still remain vigorous enough to continue to flower and
produce seed pods. They usually have a purple or yellow color and may droop or look withered.
The majority of these plants were found in areas that 1) we sprayed, and it rained within an
hour or close to an hour after spraying, or 2) we sprayed in particularly heavy dew.
- 16 -
As mentioned in the Methods and Materials section, our 2% glyphosate solution must dry for a
minimum of one hour to effectively kill the plant. In the event that rain occurred within an hour
after spraying, the Stewardship Crew made sure to revisit and re-spray the area to ensure the
effectiveness of the chemical. However, we may want to further examine the effectiveness of
the chemical in heavy dew and consider extending the required drying period to 90 minutes. A
90-minute dry period might extend the work of Stewardship interns during initial visits due to a
greater possibility of having to re-spray after rain, but it would also cut time during second visits
since the crew would not need to hand pull entire populations of zombie garlic mustard.
Another option may be to start an hour later in dryer conditions than have to re-spray
populations or risk the seed out of plants that survive chemical application as a result of
dilution by rain or dew.
Another consideration to ensure that all plants are killed completely is correct spraying
technique. Seventy percent of the plant or more should be covered with chemical after an
adequate application; and the addition of the Tracer red foam dye to the glyphosate mixture
should make the covered areas easy to see. It’s better for the plant to be dripping with
chemical than too dry. However, spraying only the top of the plant until it drips doesn’t count—
the entire length of the plant must be covered to make sure that the entire plant dies, not just
the top or sprayed section. This is important because parts of the plant can survive and resprout during the growing season to flower and produce seed.
Previous Stewardship Crews have conducted some informal experiments to test the viability of
seeds produced by plants that have been sprayed with glyphosate. In most years, initial visits
continue into the time that Alliaria petiolata starts to produce siliques and form seeds. To
understand whether these seeds are affected by chemicals, the Stewardship interns prepared
the seeds from these plants for germination by subjecting them to 100 days of cold
stratification (refrigeration). This is the required pre-treatment to prompt garlic mustard seeds
out of dormancy. None of the seeds in these experiments successfully germinated, suggesting
that treatment with glyphosate sterilizes seeds and prevents regeneration.
However, we are unsure whether seeds react the same way from a plant that has been only
partially or inadequately sprayed with chemical, or from a plant that has been rained on after
chemical application. In any case, this information should be noted only as a safeguard against
the occasional plant that may release seeds even after full chemical treatment. All staff, interns,
and volunteers should be trained in correct spraying technique from year to year and
monitored throughout the field season.
Because the weather seems to have given garlic mustard a leg up this season, significant
additions to the Stewardship Crew’s average workday and the overall length of the 2013
treatment season were necessary. Of the 42 possible work days during the season, three full
- 17 -
rain days kept the Crew completely inside, and an additional 16 days were cut short by rain.
This brings a total of 45% of our work days to have been affected by rain. To make up for lost
time, our crew normally worked 10 hour days, starting at 7 o’clock in the morning and ending at
5 o’clock in the evening.
Even with this extension of daily hours, progress in the field
was often slow. In addition to the normal year-to-year
obstacles of dense vegetation and exposure to heat,
humidity, and insects, the 2013 Crew also dealt with higher
water levels in the floodplain and an explosive mosquito
population. Whether we forded sloughs or decided to divide
units into chunks to avoid water crossings, transecting this
year took extra time. Water in the sloughs was often too
deep to walk across, even in tall rubber boots (Photo 14).
The time we took to walk back to a suitable crossing at the
end of each transect quickly added up, with no sprayed
garlic mustard to show for this added time.
Photo 14. Stewardship intern Steven
Bachleda transects through high water
in the floodplain forest.
On the other hand, if we decided to split units into chunks
between sloughs to avoid crossing the water, the trail and
Kubota were inevitably inaccessible from a particular chunk. This caused problems because the
Kubota held our supply of chemical, our drinking water, and bug spray; so if we needed to refill
our packs or grab a drink (important in the summer and especially because we wear full
jumpsuits to protect us from chemical spills), the walk back to the Kubota usually took at least
5-10 minutes, again adding up as lost time. This was the first year that the Stewardship Crew
needed to regularly extend work days to finish treating all management units by mid-July, when
most garlic mustard starts to release seed in earnest.
Simultaneous treatment of Japanese hedge parsley might also have contributed to our
extended work days, although probably not as much as rain. Normally, Stewardship interns
treat garlic mustard from May through July and subsequently treat Japanese hedge parsley
from the end of July through the first week or two of August. This year, the Stewardship Crew
treated some Japanese hedge parsley at the same time as garlic mustard, especially when we
transected through units that house known populations of both invasives. Although the focus
during this time stayed on garlic mustard, the crew still took time to look for Japanese hedge
parsley flags, find and treat populations at the flags, and treat large unflagged populations on
roadsides and edge habitats, which are the species’ preferred growing conditions. More
information about Japanese hedge parsley can be found in the Aldo Leopold Foundation
- 18 -
Stewardship Crew’s Japanese hedge parsley report, on our website at
www.aldoleopold.org/WoodlandSchool/resources.shtml.
The unexpected long work days were understandably stressful for interns at times. In future
years, we will warn potential summer interns that impromptu overtime work is a real
possibility, though it often depends solely on the weather and how fast we can progress
through our projects.
Experimentation of some new equipment that may be useful in wet years and thorough testing
of current equipment has been suggested after working through this field season. A few
unpleasant days were spent wading through sloughs in leaky boots or in boots that weren’t tall
enough to keep water out. Hip waders have been suggested for trial by next year’s interns, and
we will continue to brainstorm for other water-friendly, time-saving PPE.
Changes in protocol regarding maps and mapping
The 2013 Stewardship Crew implemented most changes in protocol recommended by the 2012
Stewardship Crew. Most of these changes improved the garlic mustard project and are
recommended for continuation next year.
The most important recommendation for next year’s Crew is to have each crew member
continue to carry a paper map while transecting. Prior to 2012, the only crew member to carry
a map of the work unit was the person collecting data with the PDA. However, maps available
in the ArcPad GIS program are limited in detail and illustration of progress. Although ArcPad
shows each garlic mustard point in a management unit, the PDA maps fail to indicate at a
glance which points have been treated and which have not; fail to clearly show all points unless
adequately zoomed in; fail to show the details of the landscape in each unit (e.g. thickness of
vegetation and sloughs), and the PDA allows no space for field notes.
Last year, one person on the crew collected data with the PDA and one person carried a paper
ArcGIS map to mark off which points had been completed. This system made it easy for the
2012 crew to see points that they missed and go back to treat them. This year, the Stewardship
Crew expanded the 2012 crew’s use of paper maps. At least two people on the 2013 crew
carried paper maps in addition to the person collecting data on the PDA. These maps were
useful not only in showing which points that we may have missed; but also helped us see which
points are incorrectly placed on the maps; helped us strategize our transecting by showing
where potential sloughs and tough spots might be; allowed us to better track our progress and
show our position in each unit; allowed us to reconcile our data when the PDA stopped
working; and gave us a space to take notes on how long we spent on each unit, where we may
have had to re-spray because of rain, which new population number we used last, and
suggestions for next time (Photo 17). Having two people carry a map further strengthened our
- 19 -
data and allows us to cross examine independent notes. We strongly suggest that the 2014
Stewardship Crew continue to carry paper maps in addition to the PDA.
Photo 15. A paper map in comparison to the map shown by the PDA garlic mustard program. The paper
maps allowed us to mark off completed points, keep track of work hours, and keep other notes in a way not
possible on the PDA.
Next year’s crew should also expand the use of paper maps by knowing how to move points
from an incorrect location to the correct location in ArcGIS. Some points shown on the maps to
be in one unit were actually found in adjacent management units. These placement errors were
particularly frustrating after spending time searching for the plots in one management unit,
deciding that the flag was missing, creating a new flag and placing it in the “correct” location as
shown by the GPS, and then finding the flag the next day in the next management unit. All
efforts should be made to correct the placement of misplaced flags, and crew members should
make sure to manually place new population locations on the ArcPad map if the Bluetooth GIS
unit isn’t working at that time. Notes taken on the 2013 paper maps and entered into our Excel
data file will alert the 2014 crew of flags that may have been incorrectly placed.
In addition to misplaced plots, paper maps also illuminated the number of duplicate garlic
mustard points existing in the management units. When the ALF Stewardship Department
included Potter Preserve in their plans for garlic mustard control, some of the same flag
numbers were assigned to plots in both the Leopold Memorial Reserve and Potter Preserve.
After selling Potter Preserve, these duplicate points were not deleted, causing some points to
show two different locations in the PDA. Although it’s not hard to figure out which of these
duplicate points is located on the Leopold Memorial Reserve, removing the duplicate from the
garlic mustard GIS file would clean up unnecessary, redundant data and streamline the data
collection process.
- 20 -
Of greater concern than duplicate points shared by Potter Preserve and the LMR are duplicate
flag numbers within or between the management units on the Leopold Memorial Reserve itself.
We came across a number of these and were unable to record data for both points, since only
one point would come up on the PDA for that particular number. We marked data for these
duplicate points on our paper maps and noted the duplicate numbers in our Excel data files.
These points should be renumbered as soon as possible for accurate data collection.
Analysis of new equipment
The 2013 Stewardship Crew still has minor deliberations on some new equipment that we
tested out this season. Instead of using 33-gallon contractor garbage bags to carry our handpulled garlic mustard through the field during revisits, we purchased six dry bags with overshoulder straps to make transporting the plants easier. The bags were especially useful through
prickly ash and other thorny species that catch and rip the plastic garbage bags. For the most
part, the dry bags worked well. However, since they have a considerably smaller volume than a
33-gallon bag, the dry bags required emptying between transects into garbage bags on the
Kubota. This was usually no problem, but once in a while a transect would yield more than the
dry bag’s capacity of garlic mustard. We made do by carrying our extra plants in bundles or by
using empty space in somebody else’s bag. In only one case did we abandon the dry bags in
favor of taking garbage bags into the field—we recognized the area as one that was washed out
by rain a little more than hour after spraying, and speculated that the chemical did not dry in
time to be effective.
We also purchased miniature clip boards to make writing on maps and flags easier in the field.
Full size clip boards are too large and cumbersome to carry, especially when each crew member
carries at a minimum a map, a marker, a quiver of flags, and a dry bag or backpack sprayer. The
miniature clip boards are half the size of normal boards and are small enough to attach to a
string around your neck or wrist. They free up hands when you clip the paper map to the board
and tie the board to yourself. However, these small boards still got in the way sometimes and
some crew members felt them not to be worth the trouble of carrying around.
Suggestions and potential changes in protocol for 2014
The most important thought in potential changes in procedure for the 2014 interns is an
examination of the most effective number of people working on garlic mustard in the field. In
2012, initial visits were conducted by Leann Wolthusen and Benjamin Van Thiel, the two ninemonth Stewardship interns that year. Two six-week interns joined them for revisits and two sixweek interns joined the crew after the garlic mustard project was finished completely.
Predictably, garlic mustard revisits went faster with four crew members in 2012 than with only
two people working on initial visits. The 2013 Stewardship crew predicted that more people in
the field would make the project go even faster. We were excited to have three six-week
interns on board for the entire garlic mustard season, totaling a crew of six people.
- 21 -
As we worked through the season, each person in the crew agreed that the most effective
number of people working together in the field is three to four. Even though six people
transecting at the same time covers a lot of ground, other factors slowed us down so that our
person-hours exploded, but the overall time we took to cover specific units kept us on par with
a two-person crew.
Our downfall was the amount of time lost waiting for other crew members to “catch up.”
Whether one half of the crew had to walk through dense prickly ash while the other half
strolled through a meadow, or five crew members hit garlic mustard plots at the same time and
had to queue up to tell their information to the data collector, we were always waiting for
someone. Although no fault of any specific person, to stay together and make decent progress
with a six-person crew was almost impossible.
One advantage to having so many people on hand to work on garlic mustard was the ability to
split people off to lead volunteers, go on field trips, or take vacations. One or two people at a
time would receive a needed break from the physical and mental stresses of the garlic mustard
project while the rest of the crew continued transecting. On these days, with a garlic mustard
crew of three or four people, we noticed a marked improvement in our progress through
management units. In a smaller group, it is much easier for crew members to keep pace with
one another, much easier for the data collector to keep up with the number of plots
encountered by fewer people at a time, and much easier to organize and encourage a group of
three or four than of five and six.
Taking breaks from transecting for garlic mustard is a luxury rarely experienced by Stewardship
Crews prior to 2013. Two full months of treating garlic mustard is arguably more mentally
taxing than physically taxing. In previous years, Stewardship interns have aimed to take one day
a week off from this project to avoid burn-out. This year, the six crew members available to
work on garlic mustard throughout the entire season allowed all three nine-month interns to
take week-long vacations and come back feeling refreshed. For this reason, we suggest that
future nine-month interns still consider hiring six-week interns during the same time period
(instead of having one intern work six weeks, and then a second intern the six weeks after that).
However, instead of attempting to work as one big group, the Stewardship Crew should
experiment with working in teams of three or four people.
Teams of interns would be beneficial in that they may “divide and conquer” management
units. Two teams would be able to tackle two small units at the same time or one large unit by
starting at opposite ends and meeting in the middle. However, some obstacles stand in the way
of team garlic mustard treatment. Although we have two utility vehicles available for our use,
we only have one 35-gallon chemical tank that loads onto to the Kubota to refill our backpack
sprayers. Two teams would need to come up with an effective way to refill, which we did often
- 22 -
during the day. This might mean that one team would have extra chemical in packs in their
vehicle that they would switch out when necessary or that the two teams would rendezvous
and refill at some point during the day. Communication between the two teams would also be
essential; this might be achieved with radios. Despite these and other possible kinks that need
to be worked out for this strategy of garlic mustard treatment, future crews should sincerely
consider the two-team system as a possible way to speed up the garlic mustard season as a
whole.
Other changes in protocol suggested by last year’s crew and found to be successful in this year’s
garlic mustard treatment included eating lunch in the field, physically attaching equipment to
your person to avoid losing gear in the field, and maintaining early start times. Although
sometimes hot and buggy, eating lunch in the field saved time from driving the 15-20 minutes
back and forth from the Legacy Center. We also found that our crew of six people managed to
lose a variety of markers, stylus pens, and maps in the dense vegetation on the Reserve.
Although small, these pieces of equipment can be relatively expensive and potentially
debilitating when lost. Attaching bright flagging tape to these items and tying them to the
jumpsuits was very effecting in keeping them available for use.
Early start times were essential last year and this year because of the heat in 2012 and because
of the rain in 2013. We recommend that the 2014 crew plan to start early during garlic mustard
season. If they find that an early start is unnecessary in the coming year, they can adjust the
timing accordingly; but if they do require an early start for one reason or another, they will be
mentally prepared.
Notes on Management Units
These notes break down suggestions for treatment protocol by unit. What may have worked
this year may not work the same way in coming years, but some institutional knowledge may
be beneficial to future interns.
Charlie’s Woods: The season starts with undoubtedly the toughest management unit. A recent
timber harvest has allowed for the establishment, spread and proliferation of Rubus spp.
Transects are long and thorny with raspberry and blackberry canes over 6 feet tall. We divided
the unit into north and south units and tackled one at a time, running east and west transects.
Sand County Foundation land borders the south edge of the unit and populations of garlic
mustard are dense and boundaries are not marked. Go only as far south as the southernmost
flag. Past the farthest flags, the south and southeast sides of Charlie’s Woods serve as a buffer
zone between Sand County Foundation Land and Aldo Leopold Foundation Land. Although hard
to ignore, you won’t be able to spray and pull all of the garlic mustard in these areas. East of the
main trail into Charlie’s Woods, we didn’t transect and went point to point instead.
- 23 -
Shack Pines: Enjoy this leisurely unit with the call of the black-billed cuckoo echoing in the
background. Concentrations of garlic mustard are highest at the edge of the pines bordering
the Shack prairie. North and south transects work great.
South Birch Row: North and south transects between the Birch Row Trail and the Shack prairie
are recommended. On the western finger of the unit, run a single east-west transect. Japanese
hedge-parsley is abundant and should be sprayed during initial garlic mustard visits.
North Birch Row: North and south transects work best. The Birch Row Trail is the divider
between North and South Birch Row. Existing alongside garlic mustard are honeysuckle,
Japanese hedge parsley, barberry, and multi-flora rose. Spray these invasives as you find them.
Anniversary: A small unit with large populations. Be thorough while transecting here as plants
can be easily over looked. It’s a small unit but it will take more time than anticipated.
Sandhill: This one is fun! Look for spring ephemerals, morels and snakes during initial visits. Run
east and west transects from the Good Oak Trail to the Shack Pines. On the western edge of the
unit (the hill) run north and south transects until the Good Oak Trail is reached.
Orchard: There are only a handful of flags in this unit but plants are abundant. Double check the
western boundary bordering Sandhill where garlic mustard is most concentrated.
Shack Foundation: Look for morels under the meat rock! This unit goes fairly quick and even
quicker when there is water covering the floodplain. North and south transects work best, and
be careful on the northern boundary – a slippery slope. There are points at the bottom of the
slope so you do have to walk down it.
Floodplain North of the Sands: Transects are awkward in this unit. The best method to go about
transecting is still to be determined. Vegetation is thick along the river and there are flags
hidden throughout. Be prepared for a slower pace and narrow transects. Take a break and
enjoy the view of the Wisconsin River or jump in to cool off.
Floodplain between Eddy Gordon and Levee: The going is about to get tough; be prepared for a
long couple of days. This unit is a good primer for the following unit. Run north and south
transects between Levee Road and the Eddy Gordon Trail. Work around the water to the best
of your abilities. Wide transects can be used in the most of the western portion of the unit
(Suevanna) to find the handful of flags that are there. The game of who can find the most deer
skulls also begins here (our skull family keeps growing!).
Lower Floodplain between Eddy Gordon and River Trail: This unit will take the most time
compared to all other units. We recommend starting at the western boundary and working
east, running north and south transects. The northern boundary for this unit is not well defined;
- 24 -
it is a slough, more evident in certain areas than others. The western boundary of the unit
should be thoroughly transected because it borders the unmanaged Sand County Foundation
land. Several new, large populations were found in 2013. Work around the water as best you
can, and park the Kubota on the Eddy Gordon Trail. Don’t let the turkeys spook you when you
jump them. Endure!
Upper Floodplain between Eddy Gordon and River Trail: You have made it to the home stretch.
This unit is the least troublesome of all the floodplain units. Again, north and south transects
work best. Once you’ve worked through the buckthorn and prickly-ash thickets, your pace will
quicken.
North of the River Trail: There are a handful of points in this unit; however, it covers a large
area. Crews have typically gone point to point if rushed for time. It is best if the unit is
transected so that crew members can scout for new populations. North and south transects
work best. Morel Madness at a few of the points!
West of Suevanna and Trail Intersection (Hell’s Corner): This unit is difficult and will leave you
feeling depleted. Do the best you can here as this unit serves as a buffer between ALF and SCF.
You can spend days spraying in here, so put a limit on the gallons you will spray at 20. Conquer
the 1-acre plot!
Clay Hill: The end is near! The 2013 crew ranked this unit as our second least favorite, just
behind Charlie’s Woods. Run north and south transects from Levee Road to Chapman Lake.
There are numerous populations in this unit that are 10 meters or larger. No new populations
were created in 2013 because the crew determined the existing plots covered the entire area of
the unit. Dogwood thickets, buckthorn slash and fallen trees make the southern portion of this
unit difficult to transect. However, it can be done!
- 25 -
Appendix A
Raw Data
Table 2. Chemical Control (Initial Visits) of Garlic Mustard by ALF Land Stewardship crew and volunteers, LMR,
Spring 2013
Gallons of
Total #
2%
Date
# of People
Location
Person Hours
Glyphosate
5/10
3
7
1
Started Charlie’s Woods
5/13
3
16.5
3.25
Charlie's Woods
5/14
3
21
4
Charlie’s Woods
5/15
3
19.5
5
Finished Charlie's Woods and started Shack
Pines Unit
5/16
5
15
3.5
Finished Shack Pines Unit and started South
Birch Row Unit
5/20
5
19.5
9.5
Finished South Birch Row, Anniversary Unit,
and Foundation Unit; started Sand Hill Unit
5/21
5
23.25
15
Finished Sand Hill Unit and Orchard Unit;
started North Birch Row
5/22
4
5
2.75
North Birch Row
5/23
4
23
9.25
Finished North Birch Row
5/24
4
21
18.5
Floodplain between Eddy Gordon and Levee
5/28
4
8.25
9.25
Floodplain between Eddy Gordon and Levee
5/29
4
28
21
Floodplain between EG and Levee
5/30
3
10.25
8.75
Floodplain between EG and Levee
5/31
3
21.75
14.5
Finished Floodplain between EG and Levee,
Suevanna, and North of the River Trail
6/2
3
15.5
15
Lower Floodplain between EG and River Trail
6/3
5
32.5
9.75
Lower Floodplain between EG and the River
Trail
6/4
5
21.5
18.5
Lower Floodplain between EG and River
6/5
6
6
5
Lower Floodplain between EG and River
- 26 -
6/6
5
27
29
Lower Floodplain between EG and River
6/7
5
17
14
Lower Floodplain between EG and River
6/10
7
32.25
10.5
Upper Floodplain between EG and River;
Sand County Foundation Roadside
6/11
6
48
22.25
6/12
5
5
0
Upper Floodplain between EG and River;
Sand County Foundation Roadside
Upper Floodplain between EG and River Trail
6/13
6
41.75
37.25
Finished Upper Floodplain between EG and
River Trail, North of the Sands, and Hell’s
Corner; continued SCF Roadside; started Clay
Hill
6/14
7
43
42.5
Finished Clay Hill and Shack Triangle
6/17
2
14
125
SCF Roadside/Terbilcox Property (with dually)
6/18
2
11
70
SCF Roadside/Terbilcox Property (with dually)
N/A
1
N/A
226
Terbilcox Property between Levee and Van
Hoosen Roads (with dually)
Totals
2-7
553.5
750
Table 3. Revisiting Garlic Mustard Populations by ALF staff, LMR, 2013.
Date
# of
Total # Person
Gallons
Location
People
Hours
Pulled*
6/17
4
30.75
N/A
Started Charlie's Woods
6/18
3
21.5
30
Charlie’s Woods
6/19
4
21
25
Finished Charlie’s Woods and Shack pines
6/20
4
30
12.85
Finished Anniversary Unit, North Birch Row, and
South Birch Row
6/21
4
14.75
12
Finished Orchard, Foundation, and Sandhill units
6/24
3
23
20
Floodplain from Levee to Eddy
6/25
4
24
10
Floodplain from Levee to Eddy
6/26
4
30
19
Finished Floodplain from Levee to Eddy and
Suevanna; started Lower Floodplain between Eddy
Gordon and River Trails
6/27
3
9.5
15
Lower Floodplain between EG and River
7/1
3
21
33
Lower Floodplain between EG and River
7/2
3
20.25
213
Lower Floodplain between EG and River
7/3
3
18.75
36
Finished Lower Floodplain between EG and River;
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started Upper Floodplain between EG and River
North of the Sands
Hell’s Corner
North of the River Trail; Clay Hill
7/5
3
4.5
0
7/9
3
6.75
75
7/10
3
18
35
Total
3-4
293.75
535.85
* The gallons of garlic mustard hand-pulled included both plants that were missed during initial visits and any plant
that was treated but did not appear dead, or had seeds/siliques that were looked as though they may still be
viable.
Table 4. Total garlic mustard removal by ALF staff and volunteers, 2003-2013.
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
*
Hours
189
275
196
184.5 361
439.75 496.25 508.25 621.25 460.1
847.25
Spray
31
221
128
183.5 243
133.25 206
208.75 348
127.15 524
(Gallons
***
Used)
Gallons
2970** 1584
1134
565
565.5 156.75 531.3
810
554
460.5
535.85
Bagged
New
No
499
180
331
157
85
286
192
301
94
120
Populations data
Found
* 2004 totals for LMR included efforts made at Potter Preserve
** In 2003, interns chose to pull adult plants at the majority of sites rather than treat with herbicide.
*** 2012 interns did not chemically treat the Clay Hill unit
****2013 hours include SCF roadside spraying and gas-powered spraying on Terbilcox property. Also, the 2013
Stewardship Crew consisted of 3-7 people instead of 2-6 in other years.
Table 5. Number of garlic mustard populations and total acres.
2009
2010
2011
Year
# of Plots
Acres
# Plots w/ Dead Stems
2012
2013
1547
11.23
1749
12.43
2040
14.15
2134
2258
10.2
14.5
123
95
121
85
13
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Works Cited
Blossey, B., V. Nuzzo, H. Hinz, and E. Gerber. 2001. Developing biological control of Alliaria
petiolata (M. Bieb.) Cavara and Grande (garlic mustard). Natural Areas Journal 21:357-367.
Blossey, B., V. Nuzzo, H. L. Hinz, and E. Gerber. 2002. Garlic mustard. Pages 365-372 in R. van
Driesche, B. Blossey, M. Hoddle, S. Lyon, and R. Reardon, editors. Biological Control of Invasive
Plants in the Eastern United States. Forest Health Technology Enterprise Team, Morgantown,
West Virginia.
“Garlic musard (Alliaria petiolata).” Invasive Species. Wisconsin Department of Natural
Resources. 5 June 2013. Web. 27 August 2013.
Milewski, Todd D. “2013 brings an about-face in Madison's weather; June was 4th wettest
month on record.” The Cap Times. 1 July 2013. Web. 1 September 2013.
Munger, Gregory T. 2001. Alliaria petiolata. In: Fire Effects Information System, [Online]. U.S.
Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences
Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/ [2013, July 16].
Razor Pro Specimen Label. Nufarm Limited. 2013. Web. 24 September 2013.
Nuzzo, Victoria. 2000. Element Stewardship Abstract for Allaria petiolata (garlic mustard).
Nature Conservancy. Arlington, Virginia.
“Species pages: Garlic mustard.” The Virtual Nature Trail at Penn State New Kensington. The
Pennsylvania State University. 5 January 2006. Web. 27 August 2013.
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