Effects of climate change, deer and invasive species on...
Transcript of Effects of climate change, deer and invasive species on...
Effects of climate change, deer and invasive species on forests Lee E. Frelich, Director, The University of Minnesota Center for Forest Ecology
Change in summer (JJA) temperature
Higher Emissions
Lower Emissions
Slide: Don Wuebbles
2010-2039 2040-2069 2070-2099
Projected Change in Precipitation: 2081-2099
Relative to 1960-
1990
NOTE: Scale Reversed
Midwest: Increasing winter and spring precipitation, with drier summers More frequent and intense periods of heavy rainfall
Slide: Don Wuebbles
White pine on its way to better climatic
zone, Ontario (upper) and a cold tree
wearing a sweater (lower).
Peter Aplin
How do trees
respond to
climate change?
Fossil pollen evidence suggests that trees respond to
gradual climate change by migration and to sudden and
large climate shifts by dying
Oak
po
llen
%
Hem
lock
po
llen
%
Hem
lock
po
llen
%
Calendar years before present
10,000 8,000 6,000 4,000 2,000 0
Hemlock and oak decline 5,000 ybp due to drought and insects. From Foster et al. 2006. Ecology 87: 2959-2966
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.
Pagami creek fire-NASA
Pagami Creek Fire, Sept 12, 2011
Lake Kawishiwi, Photos: PJ Sikorski
Brian Sturtevant-USDA Forest Service
July 1995 derecho series
From: R.H. Johns and J.S. Evans: www.spc.noaa.gov/misc/AbtDerechos
More disturbance from wind and fire in a warmer climate
Minneapolis Star
tribune
Before and after the 1999 blowdown
in the Boundary Waters, northern MN
Wind does selective weeding of the forest
Divergence of forest composition after wind versus wind/fire
combination BWCAW case study
Tornado reports per decade. Paul Huttner, MPR.
Wind + Fire = major
transformation
of the forest Photos: Dave Hansen
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
Dai, 2010, Drought under global warming,
Climate Change DOI: 10.1002/wcc.81
Comparing the 2060s with current
More drought = trees under stress and forest dieback
Photo: Dave Hansen
Impacts of deer grazing reinforcing climate change Sylvania Wilderness maple and hemlock forest in 1990
Sylvania in 2006, after the deer have eaten Pictures from Salk, Frelich, Montgomery, Calcote, and Ferrari, preliminary acceptance in Forest Ecology and Management
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
Earthworm-free site. Photo: Paul Ojanen
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
Seed emergence experiment
with endogeic and anecic
earthworms both present:
Graminoids are favored
Lawn of sedge created by earthworm and deer Photo: Paul Ojanen
Stage 2, Dendrobaena only
Stage 3, + Aporrectodea ssp.
and L. rubellus
Stage 4, + L. terrestris
Photos: J. Schlaghamersky
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)
14 Sapling growth study sites
Fisichelli study of sapling success and growth over
a 4 degree F temperature gradient in mixed boreal-
northern hardwood forests
Temperate Mixed Boreal
Overstory Type
Local Scale: 3 overstory neighborhood types
>67% Temperate
overstory tree
rel. abundance
33-67% Temperate
overstory tree
rel. abundance
<33% Temperate
overstory tree
rel. abundance
Sugar maple
Red maple
Fir/Spruce
Species Regeneration Response to:
Temp Precip pH Deer Litter Conspecific Depth Overstory
0
0/- 0
0/-
Methods: Sizing Up the Competition; Growth Measurements
Radial Growth Height Growth
Distance between terminal bud scars
‘09 ‘08 ‘07
5 species Balsam fir (Abies balsamea) White spruce (Picea glauca) Red maple (Acer rubrum) Sugar maple (Acer saccharum) Red oak (Quercus rubra)
4
5
7
10
15
17.0 17.5 18.0 18.5 19.0
Summer Temperature (°C)
He
igh
t g
row
th (
cm
yr
1)
4
5
7
10
15
17.0 17.5 18.0 18.5 19.0
Summer Temperature (°C)
He
igh
t g
row
th (
cm
yr
1)
(a) low browse pressure
(b) high browse pressure
Results: Temperate sapling relative performance ‘cooled’ by deer
A. balsamea
P. glauca
A. rubrum
A. saccharum
Q. rubra
A. balsamea
P. glauca
A. rubrum
A. saccharum
Q. rubra
A. balsamea
P. glauca
A. rubrum
A. saccharum
Q. rubra
A. balsamea
P. glauca
A. rubrum
A. saccharum
Q. rubra
A. balsamea
P. glauca
A. rubrum
A. saccharum
Q. rubra
Abies balsamea
Picea glauca
Acer rubrum
Acer saccharum
Quercus rubra
Mean summer temperature oC
Sugar maple versus spruce in the
temperate-boreal ecotone
Temp change
Deer, moose, earthworms
Temperature pushing harder than opposing forces
Boreal Temperate
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.
Serial correlation prevented maple from replacing spruce forest on sand,
but not silty clay loam, for a 2xCO2 scenario. Cohen and pastor 1991.
With serial
correlation
Silty clay loam
Sand
Sugar maple versus oak in
in the temperate zone
Temperature change,
earthworms
Deer
No net direction???
Expect mesic forest types such as northern hardwoods
to contract their niche
Loamy sand Loam Silt loam
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
Mark Stennes
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
would be necessary
The Prairie Enthusiasts
Molly McGovern
Buckthorn on rocks in northern MN Photos: Paul Ojanen
Warmer climate,
Longer growing season
More frequent
and longer
droughts
Warmer and
drier soil
Lower soil
nutrient
status
Exotic earthworms
spread faster
More deer
More fires
More wind
storms
Pests and diseases
spread faster
N deposition
CO2 fertilization
Kill seedlings
and prevent
reproduction
Kill adult trees
and lack of
replacement
Savannification
Multiple impacts of climate change at the prairie- forest border. Frelich and Reich, 2010 Frontiers in Ecology and the Environment
Disturbance severity
High Low
Late
successional
dominance
Low
High
Clearcut or
stand leveling wind
Ecosystem
under stress
from climate
Ecosystem well
adapted to climate
Thresholds for disturbance severity necessary to change
forest composition are lower when a forest is under stress
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
Layne Kennedy
Lee Frelich and clones at work during Ham Lake Fire, Seagull Lake, May 6, 2007
Questions?