Climate change in the

Dave Hansen

Climate change in the forest and lake country of northern Minnesota

Lee E. FrelichDirector, University of Minnesota Center for Hardwood Ecology

Vice President, Eastern Native Tree Society

Advisory Council, Friends of the Boundary Waters Wilderness

Board of Directors, Great River Greening

Svante August Arrheniusg(Nobel prize, Chemistry,1903)

De eloped the hotho se theor forDeveloped the hothouse theory forCO2 in 1896

Seasonal Climate Change in the US During 1951-2006

September - November December - February

June - August March - May

ClimateWizard analysis (Evan Girvetz et al. in prep.), using PRISM climate data (Daly 2006)

Birch dieback, North Shore, 2008. Photo: Dave Hansen.

Red maple taking over as birch die(upper, Photo, Dave Hansen).( pp )Red maple % change in abundance 1980-2005 (lower, from Fei, J. Forestry, 2007).

Spruce White pine

Migration maps for tree response to past climate change in 1000s years before present (M.B. Davis 1983)

Balsam fir abundance: C t FIA d tCurrent FIA compared to predictions for high emissions scenarioSource: USDA Climate and Tree Atlas

Current FIACurrent FIAabundance

Predicted high scenario

Red oak abundance: C t FIA d tCurrent FIA compared to predictions for high emissions scenarioSource: USDA Climate and Tree Atlas

Current FIACurrent FIAabundance

Predicted high scenario

NE MN Tree response to warmer climate:

D i b d j k i d iDecrease in abundance: jack pine, red pine,black spruce, white spruce, paper birch, aspen, balsam poplar, tamarack Increase in abundance:Increase in abundance:sugar maple, red maple, white pine, basswood, red oak, bur oak, green ash, yellow birchyellow birchMigrate in:Hemlock, white oak, black cherry

Bud Heinselman

Climate, forest and water feedbacks

Fewer conifersmore hardwoods

Warmer climate

Warmer waterWarmer water+pH+P in water

Global warming orGlobal warming orGlobal worming?

Earthworms are ecosystem engineers that can alter the t t f il d hstructure of soil, and change

the H2O, N and P cycles, Cdynamics and seedbed ycharacteristics on a regional scale. They also can reinforce global warming by warmingglobal warming by warming the soil

Earthworm Invasion

Temperate

No earthworms beforeTemperate

Deciduous Forests

before European settlement

(Modified from Hendrix and Bohlen 2002)

Common Earthworm Species and Ecological groups

Anecic: Lumbricus terrestris (nightcrawler) Epigeic: Dendrobaena octaedra

~ 1 in. 1 in.

Epi-endogeic: Lumbricus rubellus Endogeic: Aporrectodea caliginosa

Photo: Dave Hansen University of MNPhoto: Dave Hansen, University of MN

Before earthworm invasion…

Photo: Dave Hansen University of MNPhoto: Dave Hansen, University of MN

…and after earthworm invasion

Photo: Dave Hansen, University of MN

Soil profile, no earthworms

Photo: Dave Hansen, University of MN

Soil profile with earthworms

D i t i idth d b th

1 6

Decrease in tree-ring width caused by earthworminvasion in maple forest

11.21.41.6

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0.40.60.8

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Rin

g w

idth

i Worm freeworm invaded

00.20.4

-5 0 5 10 15 20 25 30

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Invasion timing (years)

L. terrestris litter preferencesp

Consumption of duff by earthworms Cindy Hale

High deer populations due to fragmentation and warmer climateDeer grazing is a problem forDeer grazing is a problem for many native species:red oakwhite pinewhite cedaryellow birchyyewwoodland wildflowers: Trilliumand many othersand many others

Worms + deer =major ecosystem transformationtransformation

Photos: Dave Hansen, University of MN

Forest decline syndromeat Wood-Rill (lower) ascompared to Taylor’swoods (upper)( pp )

Climate, forest, earthworm impacts on soil and runoff

Warmer climate + hardwoods

+ Worms Bare soilErosionP loss from terrestrialHigher bulk density

More runoff (flashy water levels)+P in water+P in water

Native insects play a major role in forest changeBenign native insects can have outbreaks in a warmer climateBenign native insects can have outbreaks in a warmer climateFor 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 pineacres of lodgepole pine forest, and could threaten jack pinein MN

Exotic tree pests and diseases will also reinforce warming

Emerald ash borerDavid Cappaert

More problems: wind, fire, native insects, and drought

The BWCAW derecho, July 4, 1999: the damage swaththe damage swath

Number of summertime derechos observed in 22 years

From: R.H. Johns and J.S. Evans: www.spc.noaa.gov/misc/AbtDerechos

From: R.H. Johns and J.S. Evans: www.spc.noaa.gov/misc/AbtDerechos

Derecho downburst development From COMET, 1999, modified from Weisman, 1993.

Before and after the big blowdownDifferential weeding of the forest:aspen and jack pine most likely to blow down,maple and cedar least likely

Minneapolis Star Tribune

Layne Kennedy

View of Ham Lake Fire from Seagull Palisades—midnight May 6, 2007.Layne Kennedy (left) and Gus Axelson (Right).

Layne Kennedy

Nick Fisichelli and Roy Rich, Cavity Lake Burn, Seagull Lake, July 2007. Photo: Dave Hansen, University of MN

The Cavity Lake fire aftermath. Photos: Alex Reich

Several forces are at work that may push MN foreststowards savanna:

If soils become drier for any reason sites can support fewer trees:fewer trees:

Warmer soilsHigher evaporation to precipitation ratioE th t i i th i l ti d ff lEuropean earthworms stripping the insulating duff layer

Summary of impacts on Lake Statestree speciesp

Global warming and rate of migration:All speciesAll species Sudden oak death: red oak, pin oakDeer: white cedar, yellow birch,

hit i kwhite pine, oaksEmerald ash borer: green ash, black ash, white ash

Paul Jost

Asian long-horned beetle: red maple,sugar maple, aspenHemlock woolly adelgid: hemlockHemlock woolly adelgid: hemlockMountain pine beetle: jack pineNative insects: eastern larch, others E th l d thEarthworms: sugar maple and others

Overall scheme for change at the prairie-forest border proposed by Frelich and Reich

Warmer climate, Longer growing season

More frequent and longer droughts

CO2 f ili i

Warmer and drier soil

Lower soil

Exotic earthworms spread faster

N d iti

CO2 fertilization

Lower soil nutrient statusMore deer

N deposition

More firesKill seedlingsand preventreproduction

More wind storms

Pests and diseases

Kill adult treesand lack of replacement

Savannification

Pests and diseases spread faster

Biome changes in Minnesotaduring the mid-Holocene:Species and biomes have movedin the past when climate changed and will do so again

Forest cover of central North America (green)Forest cover of central North America (green)DeFries, R., M. Hansen, J.R.G. Townshend, A.C. Janetos, and T.R. Loveland (2000), 1 Kilometer Tree Cover Continuous Fields, 1.0, Department of Geography, University of Maryland, College Park, Maryland, 1992-1993.

It is possible that the pbf will move 500 kmto the north and east, deforesting an area2X the size of California2X the size of California

Warmer climate effects on savannification and water

Warmer climate

Warmer water

Fewer trees

+ earthwormsForest pondsand lakes becomeprairie potholes

We expect the boreal forestto disappear in MN

Lee Frelich

to disappear in MN

This may provide a huge opportunity for savannaopportunity for savanna restoration….or for buckthorn

OldOld

Dave Hansen

Transitional

New

U S Endangered Species Program

Losers

U.S. Endangered Species Program

Ruth Sullivan

P k C d

Peter MirejovskyU.S. Fish and Wildlife Service

Parks Canada

Winners

Photos: Roy Rich

Sa anna of b r and northern pin oaksSavanna of bur and northern pin oaks

Photo: Dave W. Peterson

The Kandiyohi elm-oak forest—the ecological blueprint for thefuture of Minnesota forests?

Source: NOAA Pollen viewer

Rock elmDave Hanson

Mark Stennes

A forest of American basswood, elms, Kentucky coffeetree, hackberry, and oak could be the future for central and northern parts of Minnesota

Synthesis of warming climate effects on water I

Warmer climate

Warmer water

+ hardwoods,less conifersless conifers

+earthworms+P in Eutrophicationwater

Eutrophication

Variation in earth’s temperature from 1000-2100:What trajectory will we follow during the 21st Century?