Post on 03-Oct-2020
Transitioning black ash wetlands to an
EAB infested future
Brian Palik USDA Forest Service
Northern Research Station
Tony D’Amato University of
Vermont
Robert Slesak Minnesota Forest
Resources Council
The Context: millions of acres and billions of trees
The Concern: threatened by EAB, etc
The Need: adaptive strategies, including replacement trees species
• Black ash forests are a large
proportion of Lake States landbase
• 440,000 ha ( 1.1 million ac) & 1 billion
trees in Minnesota
• Glacial lake and outwash plains, muck
soils, impeded drainage
Black Ash in the Lake States and
Minnesota
Why black ash forests matter
-Timber
-Habitat
-Carbon storage
-Cultural resource
Species
Bla
ck a
sh
Bal
sam
fir
Bal
sam
popla
r
Pap
er b
irch
Am
eric
an e
lm
Gre
en a
sh
Quak
ing a
spen
Red
map
le
White
ced
ar
Yello
w b
irch
No
. p
er
ha
0
100
200
300
400
500
600
700
Overstory Species
Black ash can be the dominant species in wetland forests in the north
Why Minnesota in Unique
Palik, Ostry, Venette, et al FEM 2011
What do we know about black ash age structure & disturbance?
-Long-lived trees (300+ years)
-Strongly uneven-aged; recruitment peaks reflective of drought and canopy disturbance
-Overstory present during regeneration events; gap-based dynamics
But Black Ash Forests have Issues…
Including…
Emerald Ash Borer
Emerald Ash Borer is on the
doorstep of the largest
concentration of ash in the
North America
Very high mortality in trees
over ~ 1 inch diameter
More bad news… Climate projections for northern MN
Projected habitat changes for co-occurring
tree species in Fraxinus nigra wetlands:
-Reduced habitat suitability 50% of spp.
-Neutral: 25%
-Increased: 25%
The few future adapted species
occur only in low abundance in
these forests
Species
Bla
ck ash
Bals
am fi
r
Bals
am p
oplar
Paper
birch
Am
erican e
lm
Gre
en ash
Quakin
g aspen
Red m
aple
White
cedar
Yello
w b
irch
No
. p
er
ha
0
100
200
300
400
500
600
700
EAB is cold sensitive; warmer
winters > EAB survival
Species
Bla
ck a
sh
Am
eric
an e
lm
Bal
sam
fir
Bal
sam
popla
r
Mounta
in m
aple
Quak
ing a
spen
Speckl
ed a
lder
Sugar m
aple
Will
ow
No
. p
er
ha
0
200
400
600
800
1000
Wetland
Upland
Sapling layer is
mostly black
ash and alder..
Also, few trees in
the regeneration
layer:
-speckled alder
-hazel
-mountain maple
-dogwood
Sapling Species
No tree species
poised to replace
black ash….should
something bad
happen!
Even more bad news… Not a lot of advance regeneration of other species
Palik, Ostry, Venette, et al FEM 2012
Without Trees…
-Black ash wetlands get even wetter
-Sedge/shrubs dominate
-Tree establishment becomes difficult
-Loss of ecosystem function, habitat
The Concern:
Emerald Ash Borer Invasion
Plant Community
Litter QuantityLitter Quality Canopy Cover
Landscape context
• Ash tree abundance
• Geomorphology
• Spatial scale
Environmental stochasticity
• Precipitation
Species traits
• Habitat preferences
• Life history strategies
Landscape context
• Spatial scale
GathererShredder Scraper
Predator
Algal
CommunityFPOMCPOM
Aquatic Community (amphibian and invertebrate)
Hydroperiod
*
Youngquist et al. Wetlands 2017Loss of a
Foundational Species
There is a growing sense of
urgency among regional
organizations to find
adaptation strategies to
maintain trees in these
ecosystems
The Need:
Adaptive strategies, that keep
forests on the landscape
Questions?
0 6030 Kilometers
Large-scale manipulative experiment on Chippewa National Forest
Evaluating the Ecological Impacts of
Emerald Ash Borer in Black Ash Forests
-What are potential impacts of EAB and
associated management actions on structure
and function of black ash forests?
-Are there adaptive strategies to build site-level
resilience to EAB and climate change (i.e.,
maintain forested wetland condition)?
13
Brian Palik USDA Forest Service
Northern Research Station
Tony D’Amato University of
Vermont
Robert Slesak Minnesota Forest
Resources Council
-Conceived by Gary Swanson (CNF) in 2009
-Developed by Palik, D’Amato, Slesak in 2010
-Harvested winter 2011-12
-Planted 2011-2012
4 treatments
1. Unharvested control
2. Clearcutting
3. Group selection
4. EAB emulation
-All treatments are 1.6 ha (4 ac);
-8 replicates of each
Northern Wet Ash Swamp (WFn55);
Northern Very Wet Ash Swamp (WFn64)
The Study:
Examining:
-Hydrology: Jake Diamond, Dan McLaughlin; Virginia Tech
-Native plant communities: Chris Looney, UMN
-Natural regeneration: Chris Looney
-Amphibian communities: Melissa Youngquist, UMN
-Aquatic food webs: Melissa Youngquist; Sue Eggert, FS-NRS
-Planted regeneration: Chris Looney
-Small mammals: Alexis Grinde, NRRI-UMD
-Birds: Alexis Grinde
Group Selection
Clearcut
Girdling
Emulates EAB
Control
Treatments
Clearcut and Girdling Treatment: additional activities
Replacement Tree Species
-12 tree species: planted F2011 &/or Sp2012
-Most present in regional ecosystem:
Red Maple*, Yellow Birch*, Eastern Larch,
Eastern Cottonwood*, Black Spruce,
Balsam Poplar, Quaking Aspen, White
Cedar, American Elm*
-Two from the next southern climate zone:
Hackberry*, Swamp White Oak*
-One exotic:
Manchurian Ash*
Northeast Asia & Japan
EAB-resistant
*Future adapted: climate and EAB
Questions?
Water table response
(wet sites get wetter!)
Slesak et al. (CJFR 2014 and ongoing)
ResultsJake Diamond, Dan McLaughlin
Virginia Tech
** **
** *
** ** **
** **
Girdled and
clearcut:
-shallower
depth to water
-Group
selection:
tracks the pre-
harvest forest
-Regeneration
is challenging
in clearcut
and girdle
Herbaceous plants
Calamagrostis canadensis (bluejoint)
Carex lacustris (hairy sedge)
Carex spp.
Clearcut treatment:
-increase in herbaceous
cover
-sedges, grasses, cattails
Looney et al. FEM. 2017
Christopher LooneyDept. of Nat. Res.,
Univ. of Minnesota
A challenging
environment for tree
regeneration
Planted seedling survival (5 years)
• Survival highest for non-native,
pathologically-limited, or out-of-
range species
• Species with high survival are
predicted climate change adapted
• Survival lowest for commonly
occurring, native species
• Species with lowest survival are
often climate change mal-adapted
(predicted)
1. American elm (74)
2. Swamp white oak (69)
3. Manchurian ash (52)
4. Hackberry (43)
5. Balsam poplar (24)
6. Red maple (23)
7. Black spruce (11)
8. Tamarack (7)
9. White cedar (6)
10. Cottonwood (4)
11. Trembling aspen (3)
12. Yellow birch (3)
Results
Looney et al. CJFR 2015
Survival: Treatment x Species (5th year)
Mean Percent Survival (+/- 95% CI)
-Survival of future-adapted species was generally lower in the clearcut
-Similar patterns of survival among control, group, girdle
Survival: Species x Planting Season
-Higher fall survival: swamp white oak, Manchurian ash, balsam poplar
-Higher spring survival: black spruce, red maple
-Generally not a large difference between planting seasons (overly wet microsites were avoided with spring planting)
Planted Seedling Growth (2013 to 2015)
-Both height and diameter (relative) growth increased from the control to the group selection to the girdle treatment, to the clearcut
Results Looney et al. CJFR 2016
Growth: Treatment x Species
-Most species had highest growth in clearcut and girdle treatments, with group selection intermediate and control lowest
Relative Diameter Growth
Results
-Replacement species growth:
-Balsam poplar highest in all treatments;
-Swamp white oak and American elm moderate in all treatments,
-Manchurian ash and hackberry low in all treatments
Ecosystem Function Melissa Youngquist; Sue Eggert, FS-NRS
Leaf Litter
Carbon/Nitrogen Ratios Decomposition Rates
Black ash has higher quality litter
compared to sedge & swamp white oak
Black ash litter decomposes faster
than sedge & swamp white oak
Ecosystem FunctionResults Caddis Fly Survival
-Best survival on black ash, speckled alder, swamp white oak
-Lowest survival on balsam poplar, hairy sedge, American elm
Group Selection -consistent with ecology of the ecosystem (gap dynamics)-minimizes water table increase and limits herbaceous increase-regeneration survival is as good or better than other treatments-growth is moderate compared to clearcut and girdle
Ranking replacement species:
-Need to balance survival and growth-Consider shorter and longer-term perspectives-Factor in other ecosystem responses (food webs?)-Also, consider the best silvicultural approach
Ranking replacement species:
Rank order of 5th year
survival in group selection:
1. American elm (DED tolerant)
2. Swamp white oak
3. Manchurian ash
4. Hackberry
5. Balsam poplar
6. Red maple
7. Black spruce
8. Eastern larch
9. Northern white cedar
10.Eastern cottonwood
11.Yellow birch
12.Trembling aspen
Rank order of 3 year diameter
growth in group selection:
1. Balsam poplar
2. Eastern larch
3. Eastern cottonwood
4. Swamp white oak
5. Red maple
6. Black spruce
7. Northern white cedar
8. American elm (DED tolerant)
9. Hackberry
10.Manchurian ash
11.Yellow birch, trembling
aspen(not enough to
measure)
Shorter term?
Longer term?
Recommended
replacement species
In rank order for northern wet
forests:
1. Tamarack
2. N. white cedar
3. American elm (DED tolerant)
4. Black spruce
5. Balsam poplar
6. Yellow birch
7. Balsam fir
8. Red maple
9. Trembling aspen
10.Ash
11.Silver maple
Replacements should consider:
-Site appropriateness,
-EAB resistance
-Future climate adaptation
(swamp white oak?)
?
Ongoing and Related Efforts
• Phase 1 (this study): regeneration, amphibians, small mammals, birds,
hydrology, plant communities, food-webs
• Phase 2: Expanded range of sites across N. MN to look at natural
regeneration, hydrology, amphibians, small mammal, birds
Summary and Conclusions
• Adaptation strategies for black ash wetlands need to consider replacement tree
species, as well as the silvicultural approaches best suited to facilitate success
• Loss of trees from EAB or preemptive clearcutting, while increasing growth of some
species, shift sites towards challenging hydrologic conditions and may limit long-
term survival
• Group selection is consistent with the ecology of these systems (gap dynamics,
uneven-aged) and has generally good seedling survival, including several future
adapted species
• Balsam poplar and swamp white oak provide a good balance of growth and survival,
particular with group selection
• Fall planting may be logistically easier, has higher survival for some species, and
about the same survival as spring planting for most species
• Pre-emptive planting (before EAB) in uncut forest of tolerant, future-adapted species
may be a viable strategy
USDA Forest
Service Northern
Research Station