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