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Boreal Forests

HORT/RGSC 302

J.G. Mexal

Spring 2005

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Boreal Forests:Outline

• Definition

• Diversity

• Important Species

• Carbon budgeting

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World Forest Zones/ Sharma 1992

Boreal

Temperate mixed

Temperate evergreen

Tropical rain

Tropical deciduous

Tropical dry

Relationship between latitude and tree species

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Species Diversity- Tree Species

• Canada >50oN Picea (4 species) • Canada >45oN Pinus (9 species)• USA 25-50oN Pinus (37 species)• Mexico 15-30oN Pinus (80 species)• Brazil 10oS 100’s species /ha• Tierra del Fuego55oS Nothofagus (3

species)

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Boreal Forests: Definition– Northern Arctic Forests

• 15% of land surface area

– Location: >45oN latitude• also Nothofagus forests in So. Amer. & NZ

– Precipitation:40-90 cm(15-35”)[snow] – Temperature: mean annual T =-3 to -10oC– Soils: highly glaciated, thin

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Boreal Forests-Growth Comparison

25 mm

Black Spruce 163 yrs Eucalyptus 2yrs

25 mm

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Boreal Forest of North America

Science Findings 40:2001

50o

60o

Forestry & SocietyBoreal Forests-Important Canadian-US Species

• Black spruce (Picea mariana)

• White spruce (Picea glauca)

• Balsam fir (Abies balsamea)

• Jack pine (Pinus banksiana)

• Aspen (Populus tremuloides)

• Tamarack (Larix laricina)

• Paper birch (Betula papyifera)

Forestry & Society SE Alaska Forests (Tongass NF) /PNW-GTR 609, 2004

4.1 21%7

35%

4 21%

4.4 23%

Timberland

Reserved

Shrub

Ice/snow

Forestry & Society SE Alaska Forests /PNW-GTR 609, 2004

Forestry & Society SE Alaska Forests /PNW-GTR 609, 2004

Forest Type

AK cedar/Hemlk

LPP Mixed conifer

Mtn Hemlk

Sitka spruce

Hemlk Sit sp

WRC Hemlk

Hemlk

Ac (k) 110 10 500 200 250 680 400 1280

Vol (kk ft3)

400 50 2200 750 1300 3800 1800 7250

Productive (%)

32 0 40 27 93 84 65 92

Ann Vol (kk ft3)

4 0 20 7 20 37 20 60

Forests of Russia/J.For. 101(4):34:2003

Boreal forest/taigasTemperate broadleaf

& mixed forests

Temperate conifer forest

0

50

100

150

200

250

300

350

400

1965 1970 1975 1980 1985 1989 1990 1995 1996 1997 1998 1999

Wood Harvest

Forests of Russia/J.For. 101(4):34:2003

Year

Removal (KK m3/yr)

Major Species:Pinus silvestris, Larix sibiricaLarix gmelinii, Picea obovataAbies sibirica, Pinus sibiricaBetual pendula, Populus tremula

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Boreal Forest of North AmericaNatural Regeneration of black spruce

Science Findings 40:2001

~5cm/yr

~15cm/yr

Forestry & SocietyBoreal Forests-Important Canadian-US Species /Coombes 1992

Picea marianaBlack spruce

Forestry & SocietyBoreal Forests-Important Canadian-US Species/Coombes 1992

Larix laricina

Forestry & SocietyBoreal Forests-Important Canadian-US Species/Coombes 1992

Betula papyriferaPaper birch

Forestry & SocietyBoreal Forests-Southern Hemisphere Species/Coombes 1992

Forestry & Society Nothofagus of Tierra del Fuego, Chile

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Tropical Forests- Boreal Forests/ Longman & Jenik 1987

Annual Carbon Capture

Forestry & SocietyForests of the World/ Litter & nutrient residence time (yrs)/Kozlowski & Pallardy 1999

Forest OM N P K Ca Mg

Tropical 0.7 0.6 0.6 0.2 0.3 --

Temperate deciduous 4 6 6 1 3 3

Temperate coniferous 17 18 15 2 6 13

Boreal deciduous 26 27 15 10 14 14

Boreal coniferous 350 230 324 94 150 455

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Forest Productivity Comparison

Forest Biomass(t/ha)

Net PrimaryProductivity(t/ha)

Tropical 450 20Temperate 240 10Boreal 225 5Woodland 100 6Ag land 35 7

Climate Change in Boreal Forests/ www.whrc.org/resources/published_literature/pdf/BunnetalEarthInt.06.pdf

Strong PositivePositiveNear ZeroNegativeStrong Negative

0.60

0.70

0.50

1980 1990 1995 2000 20051985

Ps (Pg/yr)

Annual Fires (AK and NA)

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Boreal Forests--Review Questions

• Compare and contrast the carbon budgets of a tropical, temperate, and boreal forest. Don’t memorize numbers, just give concepts and relative differences.

• What is a boreal forest? Where does it occur? What is the climate?

• What are some of the major species in a boreal forest?