FOREST ECOSYSTEMS AND THEIR MANAGEMENT

Perceptions of the Forest

In the developing world, forest dwellers rely on the forest for most of the necessities for life: source of building materials, food, protein,

In the developed world, individuals use the forest for recreation, spiritual refreshment as well as material goods.

Uses and Functions of the Forest Resource:

A. Traditional Uses

1. For fodder, grazing animals

2. Food, fruits, seeds, nuts, honey

3. Medicine, herbs,

4. Fibres, gums, dyes, oils, waxes,

5. Building materials, wood for furniture

6. Wood for domestic utensils and furnishings

7. Fuelwood for domestic cooking

B. Industrial Uses

1. Sawlogs

2. Pulpwood and paper

3. Fuelwood and charcoal

4. Cork and turpentine

5. Drugs and Medicine

6. Furniture and construction materials

C. Services

1. Soil conservation

2. Water conservation and watershed protection – rivers and ponds

3. Nature conservation and biodiversity

4. Recreation and tourism

5. Carbon sink – absorbs carbon dioxide.

FOREST RESOURCES OF THE UNITED STATES

The US has about 262 million hectares (655 million acres) of forests covering 29 percent of the total land area of the United States. This forest is distributed all over the country from Alaska, the Northwestern states of Washington and Oregon, the East and Plantations of pine and black walnut of the South. About two-thirds of this forested area is classified by the US Forest Service as Commercial Timberland - of high quality timber. This ownership distribution of this commercial forest estate is as follows:

Private Owners 58%

Forest Industry Owners 14%

National Forest System 18%

Other Federal Agencies (National Park Service) 10%

Four Federal Bureaus are charged with administering and managing the nation’s forests. Among them are:

1. Soil Conservation Service, concerned with Farm Management –

Associated Forests

2. Tennessee Valley Authority, responsible for managing timber

along the Tennessee river and its tributaries

3. Fish and Wildlife Service, interested in improving forest habitat for

wildlife and fish

4. US Forest Service, a bureau of the US Department of Agriculture

responsible for managing the nations forests and promoting the

greatest good for most people over the long run

The US Forest Service was established in 1905 by President Theodore Roosevelt who appointed Gifford Pinchot (a forestry professor of Yale University) as its first Chief Forester. The Forest Service has three basic functions:

a) Administers and protects National Forests

b) Researches forest, watershed, range, and recreational management

wildlife habitat, fire, forest product development and pest control

c) Cooperates with state and private forest owners in the 50 states to

promote sound forest management.

MULTIPLE USES OF THE TEMPERATE FOREST:

By the Multiple Use - Sustained Yield Act of 1960, the US Congress required of the US Forest Service to make the greatest number of forest resources available to the greatest number of Americans. Sound multiple use management is difficult for the Service needs to weigh the needs of many people and groups. Prioritizing forest resources for harvesting is always a problem.

Thus, timber production may have priority in the Douglas fur and Western hemlock stands of Oregon and Washington while recreational values “National parks” are given higher priority in the populous regions of New York. The same act required the Forest Service to adopt a Sustained Yield philosophy in managing forests. By this system, foresters are required to ensure that the volume of trees removed from the forest each year should equal the volume removed. Thus annual decrements should be counterbalanced by annual growth.

1. A source of wood products:

The forest is a source of variety of valuable products. Commercial forests today provide raw materials for over 10,000 products worth about $30 million annually and an industry which employs over 1.5 million people. The US uses more wood per capita than any nation on earth - about 204 board feet of lumber per person per year.

2. Flood and Erosion Control

Forest vegetation reduces flooding and Soil erosion

3. Forests as Rangelands

In addition to timber, US forests frequently include considerable areas of high quality livestock forage for cattle and sheep.

4. Forests as Wildlife Habitat

The US national forests as well as many private woodlands offer excellent wildlife habitat where many animals and birds find food and shelter.

5. Forests as Wilderness, Recreational and Scientific areas.

The Wilderness Act of 1964 sought to preserve primitive areas in their natural state as National Forests, National Parks and National Wildlife Refuges as part of a National Wilderness Preservation System.

6. Forests as a source of Fuel.

The biomass of trees serve as an alternative source of fuel that is currently being explored for commercial production. At present, 80 quads of energy, an equivalent of 1.5% of energy consumed in the United States each year.

TIMBER HARVESTING METHODS

Timber can be harvested by several methods but the choice of method depends upon several factors including; biological, economic, public approval and physical conditions of the forest. The THREE main methods that have been extensively adopted in the United States are:

Shelterwood Cutting

This is a several-stage process requiring thinning and cutting. First trees of poor quality are removed both from the forest floor and from the stand itself. This opens up the forest floor for more light, and thereby enhancing seeding growth and reducing competition. The remaining trees provide some shelter for the seedlings and when the seedlings become established, some (but not all) of the mature trees are harvested. Shelterwood cutting is an efficient technique in small plots with relatively homogeneous tree species.

Clear-cutting

With this method, an entire patch of evenly aged mature trees, 16-80 hectares (40-100 acres) in area is removed, leaving an unsightly rectangular bare ground in the forest. Clear cutting is done on a rotation basis that could last for as many as 30-100 years before the cycle is completed. Clear cutting is the standard logging practice in the Northwest where matured and huge Douglas fir abounds on the Pacific Coast. The technique has also been used to harvest even-aged stands of pine in Northern Minnesota, Wisconsin and Michigan and Coniferous forests of the West. Many of the tree species that are logged by the clear-cut method (eg. Douglas fir) are not shade tolerant. Consequently, their seeds do not germinate in the shade of the forest floor. Moreover, a huge tree like the Douglas fir may not be suitable for selective cutting since it cannot be removed without badly bruising and destroying younger trees nearby.

Criticisms of Clear-cutting

1. Accelerates surface runoff

2. Increases erosion on sloping land where trees have been removed

3. Creates open area in the forest and hence promotes the blowdown of

trees during a windstorm

4. Greatly diminishes the carrying capacity of the area for some species

(e.g. deer) that use the forest as a habitat.

5. Destroys the scenic beauty of a forest converting it to ugly scars.

6. The large amount of debris that is often left behind creates a fire

hazard.

Advantages of Clear-cutting

1. It s the quickest and simplest method of harvesting

2. Shrubs, and saplings that come to be established on the logged-off site

provide cover, food, and breeding sites for a great variety of wildlife

such as rabbits, grouse, deer and songbirds.

3. It is the only way forests of species such as Douglas fir can be

regenerated.

4. It is an effective method for controlling some disease and insect

outbreaks.

Strip-Cutting

In this method, loggers remove narrow strips of mature trees of the most desirable species in a forest leaving corridors of open spaces. A typical strip-cutting involves cutting a strip 80 meters (250 feet) wide. Residual forested strips are left between the cut strips to serve as seed sources for the regrowth in the open spaces. Selective cutting is most appropriate for hardwood forests or mixed-species forests such as oak, hickory, walnut and butternut).

Advantages:

1. It minimizes environmental abuses resulting from land scaring,

accelerated runoff, soil erosion, and wildlife destruction.

2. It reduces blowdown of trees.

3. It decreases fire hazard because of the small volume of slash that is left

after the harvest

4. It results in a high rate of natural reproduction.

THREATS TO TEMPERATE FORESTS

1. Insects

Insects are a major source of tree mortality, accounting for 26.3 million acres (10.6 million hectares) in damage in 1987. In the Eastern boreal forest, Spruce budworm, a major pest destroyed about 12 million acres (4.8 million ha). Its western counterpart, the Western Spruce budworm attacked a record 10 million acres (4 million ha) of mixed coniferous forest between 1983 and 1986. The Gispy moth caused extensive damage to over 12.8 million acres (5.2 million ha) of deciduous forests in New England, New York, Pennsylvania and New Jersey in 1981. Another lesser pest is Mountain Pine Beetle which damaged over 3 million acres of pine trees in the Pacific Northwest during the 1980's.

2. Disease:

Diseases also threaten forest resources. In 1987, 52 million acres (21 million ha) were damaged in the United States. The most prevalent diseases are:

1) Fusiform Rust that attacks slash and some pines and account for 29%

of all disease damage

2) Root diseases account for another 29%

3) Dwarf mistletoe, a parasitic plant account for about 42% of all disease

losses.

3. Burning

Fire, whether naturally caused or deliberately set, destroys several acres of forest every year.

4. Acid Rain

Factories and power plants produce a number of pollutants that are carried long distances before settling on forests to destroy them with their corrosive power.

TROPICAL RAIN FORESTS

Value of Tropical Rain Forests

1. Source of food and income for nearly 2 billion people in the tropics.

2. Farming, drinking water and other activities depend upon water

supplies slowly released from tropical forests

3. A source of hardwood timber. About 1 billion cubic meters of wood are

removed from the world's tropical forests each year.

4. Provide a habitat for an estimated 3 to 7 million species of plants and

animals

5. Many modern medicine such as those that control malaria (quinine) or

mental stress (reserpine) are derived from plants that grow in tropical

forests.

6. Has a great scientific and educational value

7. Influences the weather and climate in ways not yet understood by

scientists. Transpiration and shade on the ground.

8. Absorption of Carbon dioxides

Causes of Deforestation

Underlying – Remote - Causes

1. Population pressure

2. Penetration of Capitalism

3. Inappropriate technology – unsustainable agriculture

4. Inappropriate government policies – subsidizing cattle ranching in Brazil, etc

5. Inadequate management and control – tragedy of commons)

6. Debts and Loans repayment

Immediate Causes

1. Expanding croplands for domestic feeding

2. Agricultural expansion geared towards exports

3. Commercial Logging

4. Fuelwood gathering

5. Cattle Ranching

6. Gathering Fuelwood (gathering wood and using mechanical techniques to cut timber)

Effects of Deforestation

1. Fuelwood scarcity

2. Climatic changes - Global warming

3. Loss of gene pools

4. Extinction of species

5. Increases in Carbon dioxide

Proposals for saving Tropical forests

1. Loggers and Farmers should replant where they log

2. More forests to be converted into National Parks

3. Involve local inhabitants in the management of forests