Lee Frelich's powerpoint for the "Shifting Seasons: Great Lakes Forest, Industry, Products, and Resources Summit"

1. Effects of climate change, deer
and invasive species on forests
Lee E. Frelich, Director, The University of
Minnesota Center for Forest Ecology

2. Change in summer (JJA) temperature
Higher Emissions
2010-2039 2040-2069 2070-2099
Lower Emissions
Slide: Don Wuebbles

3. Projected Change in Precipitation: 2081-2099
Midwest: Increasing
winter and spring
precipitation, with
drier summers
More frequent and
intense periods of
heavy rainfall
Relative to
1960-1990
Slide: Don Wuebbles
NOTE: Scale Reversed

4. How do trees
respond to
climate change?
Peter Aplin
White pine on its way to better climatic
zone, Ontario (upper) and a cold tree
wearing a sweater (lower).

5. Fossil pollen evidence suggests that trees respond to
gradual climate change by migration and to sudden and
large climate shifts by dying

6. Hemlock and oak decline 5,000 ybp due to drought
and insects. From Foster et al. 2006. Ecology 87: 2959-2966
10,000 8,000 6,000 4,000 2,000 0
Calendar years before present

7. John Kneurr
Fossil needles (upper row), modern
needles (second row), and hemlock
looper parts (fossil and modern).
From Bhiry and Filion (1996) Quat Res 45: 312-320.

8. Pagami creek fire-NASA

9. Pagami Creek Fire, Sept 12, 2011
Lake Kawishiwi, Photos: PJ Sikorski

10. Brian Sturtevant-USDA Forest Service

11. More disturbance from wind and fire in a warmer climate
July 1995 derecho series
From: R.H. Johns and J.S. Evans: www.spc.noaa.gov/misc/AbtDerechos

14. Minneapolis Star
tribune
Before and after the 1999 blowdown
in the Boundary Waters, northern MN

15. Wind does selective weeding of the forest
Divergence of forest composition after wind versus wind/fire
combination BWCAW case study

16. Tornado reports per decade. Paul Huttner, MPR.

17. Wind + Fire = major
transformation
of the forest
Photos: Dave Hansen

18. Native insects play a major role in forest change
Benign native insects can have outbreaks in a warmer climate.
For example, mountain pine beetle in British Columbia—a
native insect that caused massive tree mortality over 30 million
acres of lodgepole pine forest, and could threaten jack pine
in MN

19. Comparing the 2060s with current
Dai, 2010, Drought under global warming,
Climate Change DOI: 10.1002/wcc.81

20. Photo: Dave Hansen
More drought = trees under stress and forest dieback

21. Impacts of deer grazing reinforcing climate change
Sylvania Wilderness maple and hemlock forest in 1990

22. Sylvania in 2006, after the deer have eaten
Pictures from Salk, Frelich, Montgomery, Calcote, and Ferrari, preliminary acceptance in
Forest Ecology and Management

23. Global warming or
Global worming?
Earthworms are ecosystem
engineers that can alter the
structure of soil, and change
the H2O, N and P cycles, C
dynamics and seedbed
characteristics on a
regional scale

24. Earthworm-free site. Photo: Paul Ojanen

25. Heavily earthworm infested sites
without lawn. Photo: Paul Ojanen (left), Dave
Hansen (right)
Earthworms warm the soil by removing insulating O horizon,
compact the soil, cause more runoff, create lower avail-
ability of N and P, lower the species richness of native plants
and facilitate invasive plants

26. Seed emergence experiment
with endogeic and anecic
earthworms both present:
Graminoids are favored

27. Lawn of sedge created by earthworm and deer
Photo: Paul Ojanen

28. Photos: J. Schlaghamersky
Stage 2, Dendrobaena only
Stage 3, + Aporrectodea ssp.
and L. rubellus
Stage 4, + L. terrestris

29. Invasive plants that may be facilitated by
earthworm invasion:
Buckthorn (common and glossy)
Garlic mustard
Tatarian honeysuckle
Black swallowwort (Cynanchum)
Japanese barberry
Hemp nettle (Galeopsis tetrahit)
Veronica ssp.
Stiltgrass (Microstegium)

30. Fisichelli study of sapling success and growth over
a 4 degree F temperature gradient in mixed boreal-
northern hardwood forests
14 Sapling growth study sites

31. Local Scale: 3 overstory neighborhood types
Temperate Mixed Boreal
>67% Temperate 33-67% Temperate <33% Temperate
Overstory Type
overstory tree overstory tree overstory tree
rel. abundance rel. abundance rel. abundance

32. Species
Regeneration Response to:
Temp Precip pH Deer Litter Conspecific
Depth Overstory
Fir/Spruce
0 0/-
Red maple
0 0/-
Sugar maple

33. Methods: Sizing Up the Competition; Growth Measurements
5 species Radial Growth Height Growth
‘09
‘08 Distance between
Balsam fir ‘07 terminal bud scars
(Abies balsamea)
White spruce
(Picea glauca)
Red maple
(Acer rubrum)
Sugar maple
(Acer saccharum)
Red oak
(Quercus rubra)

34. Results: Temperate sapling relative performance ‘cooled’ by deer
(a) low browse pressure15
A. balsamea
Height growth (cm yr )
−1
10
A. balsamea
balsamea
A. glauca
P. balsamea
A. glauca
7
P. glauca
P. balsamea
A. rubrum
Abies balsamea
A. glauca
P. rubrum
Picea glauca
5
4
A. rubrum
A. glauca
P. saccharum
Acer rubrum
17.0 17.5 18.0 18.5 19.0 A. saccharum
rubrum
A. saccharum
Acer saccharum
(b) high browse pressure A. rubrum
Q. rubra
Quercus rubra
A. rubra
saccharum
15 Summer Temperature (°C)
Q. saccharum
A.
Q. rubra
Height growth (cm yr )
−1
10
Q. rubra
7
Q. rubra
5
4
17.0 17.5 18.0 18.5 19.0
Mean summer temperature oC
Summer Temperature (°C)

35. Sugar maple versus spruce in the
temperate-boreal ecotone
Temp change
Deer, moose, earthworms
Temperature pushing harder than opposing forces

36. Temperate Boreal
Temperate forest tree species are now invading boreal stands,
but this process is slowed by deer in some areas. For now, the
mixed forest zone is becoming broader.

37. Silty clay loam
With serial
correlation
Sand
Serial correlation prevented maple from replacing spruce forest on sand,
but not silty clay loam, for a 2xCO2 scenario. Cohen and pastor 1991.

38. Sugar maple versus oak in
in the temperate zone
Temperature change,
earthworms
Deer
No net direction???

39. Expect mesic forest types such as northern hardwoods
to contract their niche
Silt loam Loam Loamy sand

40. Mark Stennes
Ecological blueprints for a warmer climate
A forest of American basswood, elms, Kentucky coffeetree,
hackberry, and bur oak could be the future for central and
northern Minnesota, northern Wisconsin and Upper Michigan

41. If the climate trends towards
a Savanna climate on shallow
soils:
•Try for the best savanna possible (i.e.
native species, not buckthorn).
•Resources for assisted migration and
seed amplification
The Prairie Enthusiasts
would be necessary
Buckthorn on rocks in northern MN
Photos: Paul Ojanen
Molly McGovern

42. Multiple impacts of climate change at the prairie-
forest border. Frelich and Reich, 2010 Frontiers in Ecology and the Environment
Warmer climate, More frequent
and longer
Longer growing season
droughts
CO2 fertilization
Warmer and
Exotic earthworms
drier soil
spread faster
Lower soil N deposition
nutrient
status
More deer
Kill seedlings
More fires and prevent
reproduction
More wind
storms
Kill adult trees
and lack of Savannification
replacement
Pests and diseases
spread faster

43. Thresholds for disturbance severity necessary to change
forest composition are lower when a forest is under stress
Clearcut or
stand leveling wind
High
Ecosystem well
Late adapted to climate
successional Ecosystem
dominance under stress
from climate
Low
Low High
Disturbance severity

44. What does this all mean?
Global warming is about the effects of droughts, storms,
fires, bugs, worms and deer on the forest
These factors will reinforce the impacts of changing
temperature and lead to more divergence among soil types
These factors will make abrupt change after
disturbance more likely
Future forests and savannas that replace the
current forests will have novel plant composition
due to different filters on which species are successful

45. Questions?
Layne Kennedy
Lee Frelich and clones at work during Ham Lake Fire, Seagull Lake, May 6, 2007