Title: Land Use: Forests and Grasslands
1Land Use Forests and Grasslands
2Outline
- World Forests
- Forest Products
- Tropical Forests
- Swidden Agriculture
- Temperate Forests
- Harvest Methods
- Fire Management
- Grasslands
- Land Ownership and Land Reform
3WORLD LAND USES
- Earths total land area is about 133 million km2
(29 of the globe). - Approximately 11 of the earths landmass is now
used for crop production, and half of present
forests and grazing lands could be converted. - Immediate and destructive impacts on landscape
and wildlife. - Resilient if given enough time.
4World Land Use
5WORLD 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.
6How Much Forest Is There ?
- More than half of original forests and woodlands
have been converted to other uses. - Currently, forests and woodlands cover 29 of
earths land surface. (3.8 billion ha) - Greatest concern is over protection of Old-Growth
Forests. - Less than half of forests still retain old-growth
characteristics.
7Major Forest Types
8Forest 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 half of all
industrial wood, but account for about 80 of
consumption.
9Forest Products
- U.S., former Soviet Union, and Canada are largest
producers of industrial wood and paper pulp. - By 2010, China is projected to surpass Japan as
worlds largest wood importer. - U.S. 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.
10Forest Products
- At least one-third of worlds population depend
on firewood or charcoal as their principle source
of heating and cooking fuel. - Fuelwood accounts for about half of all wood
harvested worldwide. - About 1.5 billion people have less than they need.
11Forest Management
- Approximately 25 of worlds 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
forestry. - Disrupts ecological processes.
12TROPICAL FORESTS
- Although they occupy less than 10 of earths
land surface, tropical rainforests are thought to
contain - More than two-thirds of all higher plant biomass.
- At least one-half of all plant, animal, and
microbial species in the world.
13Diminishing Forests
- Tropical forests are shrinking rapidly.
- Estimated 0.8 of remaining forest is cleared
annually. - Estimates are very rough.
- Countries have economic and political reasons to
hide extent of losses. - Real losses may range 5-20 million ha annually.
- The Congo and Amazon River basins have highest
rate of deforestation.
14Swidden Agriculture
- Can be ecologically sound and sustainable if
performed carefully and in moderation. - Slash and Burn
- Hectare plot cleared, dried, and burned.
- Ashes used to prepare seedbed.
- Fast-growing crops planted to control erosion,
shade crops, and anchor soil. - Cropped intensively for 1-2 years, and then
rested 10-15 years.
15Debt-for-Nature Swaps
- Banks, governments, and lending institutions hold
nearly 1 trillion in loans to developing
countries. - Conservation organizations buy debt obligations
on the secondary market at a discount, and then
offer to cancel the debt if the debtor country
will agree to protect or restore an area of
biological importance.
16TEMPERATE FORESTS
- Northern countries have a long history of
liquidating forest resources. - Siberia contains one-fourth of the worlds timber
reserves. - Four-million ha felled annually.
- In the U.S. and Canada, two main timber
management issues are - Cutting old-growth forest remnants.
- Timber harvest methods.
17Ancient 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).
18Wilderness and Wildlife Protection
- Forest products industry employs about 150,000
people in the Pacific NW, and adds nearly 7
billion annually to the economy. - 1989 environmentalist sued USFS over plans to
clear-cut remaining old-growth forests, arguing
spotted owls were endangered and must be
protected. - Timber industry claims 40,000 jobs lost.
- Environmentalists dispute number.
19Harvest 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. - Early-successional species flourish.
- Coppicing - Encourage stump-sprouts.
- Seed-Tree - Leave few mature trees.
20Harvest Methods
- Selective Cutting - A small percentage of mature
trees are taken in 10-20 year rotation. - Can retain many characteristics of mature,
old-growth forests.
21U.S. FOREST MANAGEMENT
- USFS has historically regarded its primary job as
providing a steady supply of cheap logs to the
nations 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.
22Fire Management
- For more than 70 years, firefighting has been a
high priority for forest managers. - Smokey the Bear - Only you can prevent forest
fires. - 2002 was one of the biggest fire years on record,
with nearly 2.8 million ha of forests and
grasslands burned.
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24Fire 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, crowding out
grasses and forbs. - As woody debris accumulates, chances of a major
fire increase. - Often, attempts to stop fires cause more
ecological damage than the actual fires.
25Fire Management
- Fire ecologists favor small, prescribed burns.
- After a fire, many industry advocates encourage
salvage logging. - Removal of dead or dying trees from forests
damaged by fire or disease. - The only thinning needed to protect houses is
within 60 m around a building.
26Sustainable Forestry and Non-Timber Forest
Products
- In both temperate and tropical regions, many
certification programs are being developed to
identify sustainably produced wood products. - Forest Stewardship Council
- Increasingly, non-timber forest products are seen
as an alternative to timber production.
27GRASSLANDS
- Grasslands currently cover about 27 of the
worlds land surface. - More than 3 billion domestic livestock producing
meat and milk. - Grasslands and open woodlands are attractive for
human occupation, thus are frequently converted
to human-dominated landscapes.
28Overgrazing and Land Degradation
- About one-third of the worlds rangeland is
severely degraded by over-grazing. - Grazing animals usually exhibit selective
grazing, removing preferred species and leaving
non-preferred species to survive and reproduce. - Gradually, nutritional value of forage declines.
- Denudation of ground leads to desiccation and
desertification.
29Forage Conversion by Domestic Animals
- Ruminants are efficient at turning plant material
into protein because bacterial digestion in their
multiple stomachs allows utilization of cellulose
and other complex carbohydrates. - Worldwide, 85 of ruminant forage comes from
native rangelands and pasture. - In U.S. only 15 of livestock feed comes from
native grasslands. 90 of total grain crop is
used for livestock feed.
30Harvesting Wild Animals
- U.S. National Academy of Sciences concluded the
semiarid lands of the African Sahel can support
20-28 kg of cattle per hectare, but can produce
nearly three times as much meat from wild
ungulates in the same area.
31Rangelands in the United States
- U.S. has approximately 319 million ha of
rangeland. - Most in the West.
- About 60 is privately owned.
- Only 2 of cattle and 10 of sheep graze on
public land. - BLM manages more land than any other agency in
the U.S.. - Strong agency inclination towards resource
utilization.
32State of the Range
- Natural Resource Defense Council claims 30 of
public rangelands are in fair condition, while
55 are in poor or very poor condition. - Several wildlife conservation groups regard
cattle grazing as the most ubiquitous form of
ecosystem degradation in the southwestern U.S.. - Many call for a complete grazing ban on all
public lands.
33Grazing Fees
- Fees charged for grazing on public lands are far
below market value and represent an enormous
hidden subsidy to western ranchers. - 1999 minimum charge was 1.35 per cow per month.
- Comparable private land fees were 11.10 per cow
per month. - Estimates are that administrative costs alone are
3.21 per animal unit.
34Rotational Grazing
- Short duration confinement of animals to a small
area (day or two) before shifting them to a new
location stimulates the effects of wild herds. - Maintains forage quality.
- Keeps weeds in check and encourages growth of
more desirable forage species.
35LANDOWNERSHIP AND LAND REFORM
- In many countries, inequitable landownership is a
legacy of colonial estate systems. - World Bank estimates 800 million people live in
absolute poverty. - Political, economic, and ecological side effects
of inequitable land distribution affect people
far from the immediate location of the problem.
36Land Reform
- Throughout history, many attempts at land reform
have been undertaken. - Redistribution of landownership.
- Tenant farmers have little incentive to protect
or improve land as they do not have any long-term
benefits. - Absentee landlords have little personal contact
with the land.
37Indigenous Lands
- Indigenous people make up about 10 of worlds
population, but occupy about 25 of the land. - Possess ecological knowledge of ancestral lands.
- Our appetite for natural resources and land puts
native people and their ecosystems at risk. - Many indigenous people are fighting for their
ancestral territories.
38Summary
- World Forests
- Forest Products
- Tropical Forests
- Swidden Agriculture
- Temperate Forests
- Harvest Methods
- Fire Management
- Grasslands
- Land Ownership and Land Reform
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