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Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Forestry.

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Presentation on theme: "Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Forestry."— Presentation transcript:

1 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Forestry

2 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Outline World Forests Tropical Forests  Swidden Agriculture Temperate Forests  Harvest Methods  Fire Management

3 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. WORLD LAND USES Earth’s total land area is about 29% of globe.  11% of landmass is now used for crop production.  Half of present forests and grazing lands could be converted. - Immediate and destructive impacts on landscape and wildlife.

4 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Uses of Landmass (29% of world)

5 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. WORLD FORESTS Forests play vital ecological roles  Regulating climate, controlling water runoff, providing food and shelter for wildlife, and purifying air. Provide valuable materials.  Wood, paper-pulp. Scenic, cultural, and historic value.

6 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Forest Distribution 1/3rd of original forests and woodlands have been converted to other uses.  Forests and woodlands cover 32% of earth’s land surface.  Greatest concern is over protection of Old-Growth Forests.  Only 22% retain old-growth characteristics.

7 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. World Forests

8 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. 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. - Developed countries produce less than 1/2 all industrial wood, but account for 80% of consumption.

9 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Forest Products US, Russia, and Canada are largest producers of industrial wood and paper pulp.  Japan is world’s largest wood importer. - US is both major exporter and importer.  Buy wood and paper from Canada and processed wood products from Japan.  Sell raw logs to Japan and other countries.

10 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Forest Management Approximately 25% of world’s forests are actively managed for wood production.  Sustainable harvest is key to regeneration. - Most countries replant far fewer trees than were harvested.  Many reforestation projects involve Monoculture Cropping.  Disrupts ecological processes.

11 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. TROPICAL FORESTS Occupy 10% of landmass, and contain:  More than 2/3rds of all higher plant biomass.  At least 1/2 of all plant, animal, and microbial species.

12 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Tropical Forests Shrinking 0.8% of remaining forest cleared each year. - Countries have economic and political reasons to hide extent of losses.  Brazil has largest rainforests, and highest rate of deforestation.

13 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Tropical Forests Shrinking

14 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Deforestation in the Amazon Basin Logging Cattle grazing

15 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Tropical Forest Losses

16 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Amazon Deforestation Remains High Even selective logging destroys canopy, causes river siltation, opens roads

17 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed.

18 Desertification threatens forest edges

19 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Chipko Movement in India Women blocking mass logging, deforestation

20 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Swidden Agriculture Can be ecologically sound and sustainable if performed carefully and in moderation. Slash and Burn  Small lot cleared, dried, and burned. - Ashes used to prepare seedbed.  Fast-growing crops planted to control erosion, shade crops, and anchor soil.

21 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Cropped intensively for 1-2 years, and then rested years.

22 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Logging and Land Invasions Other major source of forest destruction  Bulldozed roads make it possible for people to move into the forest for farmland. - Forest clearing leads to river degradation through increased silt and sediment flow.

23 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Debt-for-Nature Swaps Banks, governments, and lending institutions hold nearly $1 trillion in loans to developing countries.  Conservation organizations buy debt obligations discount, and then offer to cancel the debt if the debtor country will agree to protect or restore an area of biological importance.

24 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. TEMPERATE FORESTS Northern countries have a long history of liquidating forest resources.  Siberia contains 1/4 of the world’s timber reserves. - Asian companies cutting 10 mil. acres/year

25 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Temperate Forests in the U.S.

26 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. 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 2nd only to tropical rainforests in biodiversity. - Accumulate more biomass in standing vegetation per unit area.  Less than 10% of virgin temperate rainforest remain  (80% scheduled to be cut).

27 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed.

28 Wilderness and Wildlife Protection Forest products industry employs about 150,000 people in the Pacific NW Adds nearly $7 billion annually to the economy. Recreation has 16x jobs.

29 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Spotted Owl controversy  1989 environmentalists sued USFS over plans to clear-cut remaining old-growth forests,  Argued spotted owls were endangered and must be protected.

30 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Spotted Owl controversy

31 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Spotted Owl controversy - Timber industry claims 40,000 jobs lost.  Environmentalists dispute number.  Other reasons  Mechanization  Clear-cutting  Export of logs to Japan

32 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Harvest Methods Clear-Cutting - Every tree in a given area is cut regardless of size.  Fast and efficient, but wastes small trees, increases erosion, and eliminates wildlife habitat.  Coppicing - Encourage stump-sprouts.  Seed-Tree - Leave few mature trees.  Shelterwood - Remove in series of cuts.

33 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Harvest Methods Strip Cutting - Harvesting all trees in a narrow corridor. Selective Cutting - A small percentage of mature trees are taken in year rotation.  Can retain many characteristics of mature, old-growth forests.

34 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Menominee Sustainable Forestry

35 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed.

36 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.

37 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. FIRE

38 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Fires caused by poor logging practices Wisconsin, 1871: Deadliest forest fire in recorded world history kills 1,200-1,500

39 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Southeast Asian Rainforest Fires, 1997 Palm oil plantations

40 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Mexico/Central America Rainforest Fires, 1998 Cover for illegal logging

41 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Brazilian Amazon Rainforest Fires, 1999 Land-hungry farmers

42 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Fire Management Recent studies show fire plays an important role in many forested ecosystems.  Eliminating fire has allowed shrubs and small trees to fill some forest floors. - As woody debris accumulates, chances of a major fire increase.  Often, attempts to stop fires cause more ecological damage than the actual fires.

43 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Fire Suppression: Wisconsin River Bluffs at Sauk City, 1870s-1990s

44 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Fire Management For 30 years, the NPS has followed a policy of allowing some natural fires to burn, and even setting some prescribed fires.  But after 70 years of fire suppression, fuel has now built up to a point where fires can easily escape “control.” - The dilemma is how to remove excess fuel while protecting property, human life, and forest ecosystems.

45 Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Yellowstone Fires, 1988


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