1 Land Use: Forests World Land Uses World Forests Tropical Forests Temperate Forests What is a forest?

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Land Use: Forests

• World Land Uses• World Forests• Tropical Forests• Temperate Forests

What is a forest?

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CS Fig 12.32

Includes all wooded land, whether inOld-growth, secondary growth, orplantation

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CS Fig 12.3

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World Resources Institute: Frontier forest 8,000 years ago

http://www.igc.org/wri/forests/index.html

Frontier forests = undisturbed by humans

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World Resources Institute: Frontier forest today

Frontier forests = undisturbed by humans

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Fig 12.3

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Forest Distribution

• Almost one half of original forests and woodlands have been converted to other uses.– Currently, forests and woodlands cover 32% of

earth’s land surface. (4.2 billion ha)– Greatest concern is over protection of Old-Growth

Forests.

• Only 22% of forests still retain old-growth characteristics.

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Reasons Forests are Important to Nature

• Help regulate climate (O2/CO2)

• Minimize surface water runoff• Provide wildlife habitat• Purify water and air• Scenic, cultural, and historical value

(why it’s good to leave forests intact)

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Mudslides after Hurricane Mitch

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Forest Products

• Wood plays a part in more activities of the modern economy than any other commodity.

– Industrial Timber and unprocessed logs account for about half of worldwide wood consumption.

• Timber• Paper• Fuel (raw wood and charcoal)

• Developed countries produce less than half of all industrial wood, but account for about 80% of consumption.

(why people want to cut forests down)

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CS Fig 12.7

Which kind of forest isbeing lost morethan anyother rightnow?

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Satellites make it possible to document deforestation accurately (and to the minute)

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Fig. 14.12

Cattle grazing in CostaRica

Settlers encroach whenroads are built

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Reason for Tropical Forest Losses

• Governments Building Paved Roads– Make it possible to access forest products for

logging more economically

• Demographic Transition– Many people in developing countries practice subsistence

farming– As population grows, area cut for farms grows

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Effect of paving roads in Brazilian rainforest

CS Fig 12.8

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Forests cut for farming as population in US grew

Some forests re-grow after demographic transition

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The choices of a Costa Rican land owner

• “Mine” forest – one infusion of cash– Then:

• Plantations – wait for trees to grow in

• Cattle ranch – severe erosion created

• Sustainable forestry– What is incentive to

practice sustainable forestry?

– Who benefits? Land owner or society?

• Incentive for forest-friendly policy making

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Regions in North America where Primary Forest Threatened

Source:WRI

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Ancient Forests of the Pacific Northwest

• Redwoods can reach 3-4 m in diameter, 90 m in height and 1,000 years in age.– Temperate rainforests are second only to tropical

rainforests in terrestrial biodiversity.• Accumulate more biomass in standing vegetation per unit

area than any other ecosystem on earth.

• Less than 10% of virgin temperate rainforest remain (80% scheduled to be cut in the near future).

23Clear cuts in Washington State’s Gifford Pinchot Nat. Forest, Fig. 12.12

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What is threatening species?

• Fragmentation of forests• Lack of age structure• Lack of diversity• Atmospheric pollution

Can have quantity, but without qualityit’s not the same

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Northern Spotted Owl

CS Fig 12.16

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The last logger?

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How do we manage a forest sustainably?

• Clear cutting? Not on a large scale

Alternatives:• Selective cutting• Strip cutting• Clear cut with small and large

reserve areas

• Fire?

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Selective Cutting

• Small percentage of trees removed over 10-20 year rotation

• Thin so that improves growth of remaining trees• Maintains some of age structure of old-growth

forest• Logs taken out carefully• Reduces erosion and run-off

Case study: Menominee Nation (p. 244)

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Strip Cutting

• Harvest all trees in narrow strip• No burning or crops• Strip quickly regenerates (seeds nearby)• Use both large and small trees

• in tropical forest, better than selective cutting

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34Williams 1989

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Below-Cost Salvage Sales

• USFS has historically regarded its primary job as providing a steady supply of cheap logs to the nation’s timber industry.– Often, timber prices have not been enough to

repay management costs.• Hidden subsidy to timber industry.

– USFS builds roads in order for timber companies to extract trees.

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What can YOU do?

• Reuse and recycle paper! Market is booming right now!

• Use e-mail/conserve paper• Buy sustainably harvested wood• Don’t eat at fast-food restaurants that purchase

beef from cattle grazing on deforested rainforest land (rainforestweb.org)

• Buy sustainably harvested goods from forests (see the Forest Stewardship Council at www.fscus.org)

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The End.

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