Transcript Box 8 - NIIPP

Plant Risk Assessment &
Management Protocol for MN
Berberis thunbergii – Japanese Barberry
MN Noxious Weed Advisory Committee
www.mnnoxiousweeds.wikispaces.com
Tim Power, Minnesota Nursery and Landscape Association
History of the Noxious Weed Advisory
Committee
• Early on, MN noxious weeds were ag weeds
• MNLA became involved after listing of
purple loosestrife in the mid-1980’s
• Excellent noxious weed plan developed in
2001-2002, then program was de-funded
by state budget cuts
• MDA convened study group in 2007,
including stakeholders like the MNLA
History of the Noxious Weed Advisory
Committee
• In 2009, the MN legislature completed
major revisions to MN Noxious Weed Law
• Three sections were added
– Noxious Weed and Invasive Species Account
– Grant Program
– Advisory Committee
• In 2013, added category definitions to
statute, including Specially Regulated
Duties of the Noxious Weed
Advisory Committee
• Advise the Commissioner regarding responsibilities
under the noxious weed program
• Evaluate species
– invasiveness, difficulty of control, cost of control,
benefits of a species, injury caused by a species
• Develop weed categories for listing noxious weed
species and management criteria for each category
• Recommend whether and where an
evaluated species should be listed
• Reevaluate species every 3 years
Lythrum salicaria – Purple Loosestrife
Noxious Weed Advisory Committee
• Committee representation = Stakeholders
• Science-based/evidence-based species
evaluation process, called a Risk Assessment
• Species evaluations DO NOT = listing, nor do
they mean a species is “bad”
Plant Risk Assessment & Management
Protocol for Minnesota
• A tool for objective assessment of:
– potential risks associated with plant
introductions
– regulation and management of harmful
species already in the state
• Balances potential negative
impacts with recognized
benefits
• Decision-tree process
Petitioning Noxious Weeds
Risk Assessment for Japanese Barberry
• Why conduct a risk assessment
for Japanese barberry (Berberis
thunbergii)?
– Japanese barberry was observed
naturalizing in forests in MN and
was known to be an invasive
species in the eastern U.S.
– Information about the level of risk
posed by Japanese barberry in
Minnesota was needed
Southeastern
Minnesota,
MN DNR
photo
New York,
NY Dept. Env.
Cons. photo
New Jersey,
New Jersey
Hills photo
Eastern US,
Natalie
Solomonoff
photo
Risk Assessment for Japanese Barberry
• Box 1: Is the plant species or genotype nonnative?
– Yes, it is native to Japan
– Go to Box 3
Berberis
thunbergii
Shade Tolerant
Deer Resistant
Risk Assessment for Japanese Barberry
• Box 3: Is the plant species, or a related
species, documented as being a problem
elsewhere?
– Yes
• US Forest Service Eastern Region Category 1 plant
(non-native, highly invasive plants which invade
native habitats and replace native species)
• Prohibited invasive plant in MA, NH
• Naturalized in 30 states and 2 Canadian provinces
– Go to Box 6
Risk Assessment for Japanese Barberry
• Box 6: Does the plant species have the
capacity to establish and survive in
Minnesota?
– Yes
• Used heavily in landscapes
• Hardy in zones 4-9
– Go to Box 7
Risk Assessment for Japanese Barberry
• Box 7: Does the plant species have the
potential to reproduce and spread in
Minnesota?
– Yes
• Known to naturalize in MN
• Spreads by:
– Animal-transported seed to new sites
– Layering branches within a site
• No natural controls are
documented
– Go to Box 8
Japanese barberry distribution
www.EDDMaps.org Sept. 2012
Afton State Park – June 2011
Afton State Park – June 2011
Afton State Park – June 2011
Afton State Park – June 2011
Box 8
• Box 8: Does the plant species pose
significant human or livestock concerns or
have the potential to significantly harm
agricultural production, native ecosystems,
or managed landscapes?
– If yes, go to Box 9
– If no, the plant species is
not currently believed to
be a risk
Berberis thunbergii
‘Aurea’
Box 8 – Questions to Consider
• 8A: Does the plant have toxic qualities, or
other detrimental qualities, that pose a
significant risk to livestock, wildlife, or
people?
– No
– Go to Question B
Berberis thunbergii var.
atropurpurea
‘Rose Glow’
Box 8 – Questions to Consider
• 8B: Does, or could, the plant cause
significant financial losses associated with
decreased yields, reduced crop quality or
increased production costs?
– No
– Go to Question C
Berberis thunbergii and var. atropurpurea
Small size, desirable habit, and unique colors
Box 8 – Questions to Consider
• 8C: Can the plant aggressively displace
native species through competition
(including allelopathic effects)?
– Forms dense thickets in native areas,
according to studies on the Eastern seaboard
(Silander and Klepis 1999, Harrington et. al.
2006) and MN DNR observations in MN.
– No mention found of allelopathy.
– If yes, go to Box 9; if no go to additional
questions under Box 8
Box 8 – Questions to Consider
• 8D: Can the plant hybridize with native
species resulting in a modified gene pool
and potentially negative impacts on native
populations?
– No
– Go to Question E
Berberis thunbergii
‘Golden Nugget’
Box 8 – Questions to Consider
• 8E: Does the plant have the potential to change
native ecosystems (adds a vegetative layer,
affects ground or surface water levels, etc.)?
–
–
–
–
–
Soil under Japanese barberry has a higher pH and higher nitrification and mineralization rates
(Ehrenfeld et al. 2001).
Japanese barberry leaf litter is higher in nitrogen than native species and decomposes more rapidly
(Ehrenfeld et al. 2001).
Soils under Japanese barberry differ in microbial community structure and function (Kourtev et al.
2002).
Timing of nutrient uptake and deposition differs from native species, and altering soil functions
could contribute to ecosystem-level changes (Ehrenfeld et al. 2001, Ehrenfeld 2004).
Ehrenfeld et al. (2001) note that while densities of Japanese barberry start out low, over time they
alter the soil by increasing nutrient levels; this makes the site more favorable for additional Japanese
barberry plants, leading to dense populations and more altered soils over time. Cassidy et al. (2004)
found that Japanese barberry does better on sites with higher nitrogen.
– If yes, go to Box 9; if no go to additional questions
under Box 8
Box 8 – Questions to Consider
• 8F: Does the plant have the potential to
introduce or harbor another pest or serve as
an alternate host?
–
–
–
This has not been documented, but there is some concern.
Common barberry (Berberis vulgaris) has been widely eradicated because it is a host of
wheat rust. Japanese barberry is not a host of wheat rust. However, Connolly et al. (2013)
note that Berberis x ottawensis (B.thunbergii x B.vulgaris) is relatively common in the wild in
Mass. and Conn. and may be capable of producing some viable seed and pollen.
Emerging wheat rust Ug99: If this rust strain reaches North America it would cause extensive
damage to US crops and cause millions/billions in crop losses. At this time there is no
evidence that Japanese barberry can serve as a host to the stem rust fungus Ug99. Because
other barberry species are hosts and not all Japanese barberry cultivars have been tested
(some may be hybrids), Canada is not allowing additional Japanese barberry cultivars into
Canada except those that are already on its approved list.
– If yes, go to Box 9; if no the species is not
currently believed to be a risk
Box 8
• Box 8: Does the plant species pose
significant human or livestock concerns or
have the potential to significantly harm
agricultural production, native ecosystems,
or managed landscapes?
– If yes, then go to box 9
– If no, then the plant
species is not currently
believed to be a risk
Berberis thunbergii var. atropurpurea
Box 9
• Does the plant species have clearly defined
benefits that outweigh associated negative
impacts?
– If yes, go to Box 11 and determine if the
species should be designated as a Specially
Regulated Plant
– If no, go to Box 10 to determine if the species
should be designated as a Prohibited or
Restricted Noxious Weed
Box 9 – Questions to Consider
• 9D: Is a non-invasive, alternative plant material
commercially available that could serve the same
purpose as the plant of concern?
– Sterile cultivars of Japanese barberry are under development at the University of
Connecticut. Additionally, there are currently available Japanese barberry cultivars
that have relatively low seed production.
– Alternatives are suggested on various websites (all of these suggestions may not be
appropriate for MN):
– MN Department of Natural Resources / Leatherwood (Dirca palustris), Downy Arrowwood
(Viburnum rafinesquianum), American Hazel (Corylus americana), Beaked Hazel (Corylus cornuta)
– Midwest Invasive Plant Network / Tilia cordata (Littleleaf linden),
Buxus spp. (Boxwood 'Glencoe' or
'Green Velvet'), Ribes alpinum 'Green Mound' (Alpine Currant), Fothergilla major (Large Fothergilla), Cotoneaster
divaricatus (Spreading Cotoneaster), Ilex verticillata (Winterberry Holly), Rosa rubrifolia (Redleaf Rose), Rosa
'Knockout' (Knockout Roses), Cotinus coggygria (Smoke bush), Physocarpus opulifolius 'Diablo,' 'Summer Wine',
Coppertina' and 'Center Glow' (Ninebark), Weigela florida 'Wine and Roses', ('Wine and Roses' Weigela)
– National Park Service / Bayberry (Myrica pensylvanica), Ink-berry (Ilex glabra), winterberry (Ilex
verticillata), Arrow-wood (Viburnum dentatum), Mountain Laurel (Kalmia latifolia), Ninebark (Physocarpus
opulifolius), and hearts-a-burstin' (Euonymus americana)
Box 9 – Questions to Consider
• 9D: Is a non-invasive, alternative plant material
commercially available that could serve the same
purpose as the plant of concern?
– Natural resource organizations list alternatives
– Survey of horticultural industry
indicated that members did not
see a viable alternative to
Japanese barberry
Berberis thunbergii
‘Cherry Bomb’
Box 9 – Questions to Consider
• 9B: Is the plant an introduced species and can its spread
be effectively and easily prevented or controlled, or its
negative impacts minimized, through carefully designed
and executed management practices?
– The spread of Japanese barberry cannot be easily prevented or controlled once it
is introduced.
– Birds can spread seed.
– Offspring of cultivars (such as purple or yellow-leaved forms) can be green making
it difficult to tell which cultivar was a parent to a naturalized barberry plant (Lehrer
et al. 2006). However, there are cultivars with low seed production which may be
less likely to be invasive. The Connecticut Nursery and Landscape Association
implemented a voluntary phase-out of 25 heavy-seeding Japanese barberry
cultivars in 2010.
– It is difficult to control the spread of woody species once they are widely
distributed. Methods for Japanese barberry control are similar to those for
buckthorn or other woody invasives – very time and labor intensive.
– If yes go to Box 11, if no go to Question 9C
Box 9 – Questions to Consider
• 9B: Is the plant an introduced species and can its spread
be effectively and easily prevented or controlled, or its
negative impacts minimized, through carefully designed
and executed management practices?
– The spread of Japanese barberry cannot be easily prevented or controlled once it
is introduced.
– Birds can spread seed.
– Offspring of cultivars (such as purple or yellow-leaved forms) can be green making
it difficult to tell which cultivar was a parent to a naturalized barberry plant (Lehrer
et al. 2006). However, there are cultivars with low seed production which may be
less likely to be invasive. The Connecticut Nursery and Landscape Association
implemented a voluntary phase-out of 25 heavy-seeding Japanese barberry
cultivars in 2010.
– It is difficult to control the spread of woody species once they are widely
distributed. Methods for Japanese barberry control are similar to those for
buckthorn or other woody invasives – very time and labor intensive.
– If yes go to Box 11, if no go to Question 9C
CT Voluntary Phase-Out
Note: New research by Knight et al. (2011)
demonstrates that low-fecundity cultivars may
still be invasive and that the only “safe” cultivars
are sterile cultivars that cannot produce viable
seed or reproduce asexually.
NWAC Recommendation
• Box 11 – Should the plant species be allowed in Minnesota via a
species-specific management plan; designate as specially regulated?
• Answer – Yes. The Connecticut Nursery and Landscape Association
implemented a voluntary phase-out of 25 heavy-seeding Japanese
selections in 2010. Wisconsin is proposing a three-year phase-out and
eventual ban of the same CT selections. Minnesota should implement
a three-year phase-out of the seediest Japanese barberry selections
(using the CT list), followed by a ban of those seediest selections.
Future selections with >600 seeds/plant should be banned as well.
Ongoing sterility and invasiveness research on Japanese barberry
should be monitored closely. If and when horticulturally-acceptable
seedless cultivars of Japanese barberry are developed and successfully
in trade, revisions should be considered in the seediness level of
Japanese barberry cultivars considered “acceptable to plant”.
Current Status = Step 4
Questions?
www.mnnoxiousweeds.wikispaces.com
Berberis thunbergii – Fruits & Seedling