|Forest and Range|
Many national governments have established forest and range policies. Rangeland, land that supplies forage for grazing and browsing animals, covers almost one-half of the ice-free land on earth. More than three billion cattle, sheep, goats, camels, buffalo, and other domestic animals graze on rangelands.
These animals are important in converting forages into milk and meat, which provide nourishment for people around the world. Forests cover almost 30 percent of the earth and provide humans with lumber, fuel woods, food products, latex rubber, and valuable chemicals that constitute prescription and nonprescription drugs.
Rangelands and forests also function as important ecosystems that help provide food and shelter for wildlife, control erosion, and purify the atmosphere. Forests and rangelands have been undergoing destruction and degradation at alarming rates at the hands of humans.
Protecting Forests and Rangelands
The nearly 15 billion acres of forest that originally existed on the earth have been reduced to approximately 11 billion acres by human conversion of land to cropland, pastureland, cities, and non-productive land. Forests, if properly maintained or left alone, are the most productive and self-sustaining ecosystems that land can support.
Tropical rain forests are the natural habitat for at least 50 percent, and possibly up to 90 percent, of the species on earth. In the late 1990’s, Harvard biologist Edward O. Wilson stated that 25 percent of the earth’s species could become extinct by the year 2050 if the current rate of tropical forest destruction were not stopped.
Many national governments have established policies for protecting forest habitats and the biological diversity found within them. National parks and reserves provide protection for both forests and rangelands. Some countries have laws that prohibit clearing, burning, or logging of particular forests.
China, which suffered from erosion and floods as a result of centuries of deforestation, began an impressive reforestation campaign during the 1990’s, planting almost 11 million acres of new trees.
Korea attained 70 percent reforestation after losing almost all its forested land in a civil war during the 1950’s. Japan has enacted strict environmental laws, which have allowed it to reforest 68 percent of its land area.
Japan has relied upon imported timbers in order to allow its new forest projects to flourish. Even with such worldwide success in reforestation, it is estimated that protection and sustainable management of forests and rangelands still need to be increased by a factor of three if forests are to be saved.
Management policies must sustain and protect biodiversity; old-growth forests; riparian areas; threatened, endangered, and sensitive species; rangeland; water and air quality; access to forests; and wildlife habitat.
The Forest Service provides inexpensive grazing lands for more than three million cattle and sheep every year, supports multimillion-dollar mining operations, maintains a network of roads eight times longer than the U.S. interstate highway system, and allows access to almost one-half of all national forest land for commercial logging. The Forest Service is responsible for producing plans for the multiple use of national lands.
Sustainability policies require that the net productive capacity of the forest or rangeland does not decrease with multiple use. This involves making sure that soil productivity is maintained by keeping erosion, compaction, or displacement by mining or logging equipment or other motorized vehicles within tolerable limits.
It further requires that a large percentage of the forest remains undeveloped so that soils and habitats, as well as tree cover, will remain undisturbed and in their natural state.
The RPA and NFMA, along with the Endangered Species Act (ESA) of 1973, mandate policies that encourage the proliferation of species native to and currently living in the forest. Natural ecosystem processes are followed to ensure their survival.
Even though forests and rangelands are required to be multiple-use areas, policy maintains that there can be no adverse impact to threatened, endangered, or sensitive species. Species habitats within the forest are to remain well distributed and free of barriers that can cause fragmentation of animal populations and ultimately species loss.
If a forest contains fragmented areas created by human activity, corridors that connect the forest patches are constructed. In this way species are not isolated from one another, and viable populations can exist.
The Forest Service creates artificial habitats to encourage the survival of species in cases of natural disaster. When Hurricane Hugo devastated the Francis Marion National Forest in South Carolina in 1989, winds snapped 90 percent of the trees with active woodpecker cavities in some areas of the forest.
The habitat destruction caused 70 percent of the red-cockaded woodpecker population to disappear. The Forest Service and university researchers created nesting and roosting cavities to save the woodpeckers.Within a four-year period, the population had dramatically recovered.
Timber, Oil, and Mineral Leasing
|Timber, Oil, and Mineral Leasing|
There must be reasonable assurance that stands managed for timber production can be adequately restocked within five years of the final harvest. Further, no irreversible resource damage is allowed to occur.
Policy further requires use of the silviculture practices that are best suited to the land management objectives of the area. Cutting practices are then monitored. The 1990’swere characterized by a trend toward restricting logging methods in order to protect habitats and preserve older stands of trees.
In the 1993 Renewable Resource Assessment update, the Forest Service found that timber mortality, at 24.3 percent, was still interfering with biological diversity. Some forested areas were withdrawn from timber production because of their fragility.
Multiple use under the NFMA allowed forests to be available for oil and gas leasing. Certain lands were exempted from mineral exploration by acts of Congress or executive authority.
However, the search for and production of mineral and energy sources remained under the jurisdiction of the Forest Service, which was charged to provide access to national forests for mineral resources activities. The Federal On-Shore Oil and Gas Leasing Reform Act of 1987 gave the Forest Service more authority in making lease decisions.
Pest and Weed Control
|Pest and Weed Control|
Any decision to use a particular pesticide must be based on an analysis of its effectiveness, specificity, environmental impact, economic efficiency, and effects on humans.
The application and use of pesticides must be coordinated with federal and state fish and wildlife management agencies. Pesticides can be applied only to areas that are designated as wilderness when their use is necessary to protect or restore resources in the area.
Other methods of controlling disease include removing diseased trees and vegetation from the forest, cutting infected areas from plants and removing the debris, treating trees with antibiotics, and developing disease-resistant plant varieties.
Forest Service policy on integrated pest management was revised in 1995 to emphasize the importance of integrating noxious weed management into the forest plan for ecosystem analysis and assessment. Noxious weed management must be coordinated in cooperation with state and local government agencies as well as private land owners.
Noxious weeds include invasive, aggressive, or harmful non indigenous or exotic plant species. They are generally opportunistic, poisonous, toxic, parasitic, or carriers of insects or disease. The Forest Service is responsible for the prevention, control, and eradication of noxious weeds in national forests and grasslands.
In North Dakota, one strategy for promoting weed-free forests uses goats to help control leafy spurge. The goats graze on designated spurge patches during the day and return to portable corrals during the night.
A five-year study found that the goats effectively reduced stem densities of spurge patches to the extent that native livestock forage plants were able to reestablish themselves.
A strategy that has been implemented in Wyoming, Colorado, Idaho, Utah, and Montana requires pack animals on national forest land to eat state-certified weed-free forage.
Another strategy involves the use of certified weed-free straw and gravel in construction and rehabilitation efforts within national forests. Biocontrols, herbicides, and controlled burning are also commonly used during IPM operations in forests.
Other Protection Issues
Natural watercourses and their banks are referred to as riparian areas. The plant communities that grow in these areas often serve as habitats for a large variety of animals and birds and also provide shade, bank stability, and filtration of pollution sources.
It is therefore important that these areas remain in good ecological condition. Riparian areas and streams are managed according to legal policies for wetlands, floodplains, water quality, endangered species, and wild and scenic rivers.
Dirt roads in national forests are often closed when road sediment pollutes riparian areas and harms fish populations. Forest and rangeland roads are also closed to prevent disruption of breeding or nesting colonies.
Seemingly harmless human endeavors—such as seeking mushrooms, picking berries, or hiking in the forest—can cause problems for calving elk and nesting eagles. Therefore, the amount of open roads in the forest is being reduced in order to preserve habitat and return land to a more natural state.
Fire management is important to healthy forests. In many cases fires are prevented or suppressed, but prescribed fires are used to protect and maintain ecosystem characteristics. Some conifers, such as the giant sequoia and the jack pine, will release their seeds for germination only after being exposed to intense heat.
Lodgepole pines will not release their seeds until they have been scorched by fire. Ecosystems that depend on the recurrence of fire for regeneration and balance are called fire climax ecosystems. Prescribed fires are used as a management tool in these areas, which include some grasslands and pine habitats.
In 1964 the U.S. Congress passed the Wilderness Act, which mandates that certain federal lands be designated as wilderness areas. These lands must remain in their natural condition, provide solitude or primitive types of recreation, and be at least 5,000 acres in area. They usually contain ecological or geological systems of scenic, scientific, or historical value.
No roads, motorized vehicles, or structures are allowed in these areas. Furthermore, no commercial activities are allowed in wilderness areas except livestock grazing and limited mining endeavors that began before the area received wilderness designation.
Grazing Practices and Problems
|Grazing Practices and Problems|
The rate of loss for grazing lands worldwide is three times that of tropical forests, and the area lost is six times that of tropical forests. There are more threatened plant species in North American rangelands than any other major biome.
Rangeland grasses are known for their deep, complex root systems, which makes the grasses hard to uproot. When the tip of the leaf is eaten, the plant quickly regrows.
Each leaf of grass on the rangeland grows from its base, and the lower half of the plant must remain for the plant to thrive and survive. As long as only the top half of the grass is eaten, grasses serve as renewable resources that can provide many years of grazing.
Each type of grassland is evaluated based on grass species, soil type, growing season, range condition, past use, and climatic conditions. These conditions determine the herbivore carrying capacity, or the maximum number of grazing animals a rangeland can sustain and remain renewable.
Overgrazing occurs when herbivore numbers exceed the land’s carrying capacity. Grazing animals tend to eat their favorite grasses first and leave the tougher, less palatable plants. If animals are allowed to do this, the vegetation begins to grow in patches, allowing cacti and woody bushes to move into vacant areas.
As native plants disappear from the range, weeds begin to grow. As the nutritional level of the forage declines, hungry animals pull the grasses out by their roots, leaving the ground bare and susceptible to damage from hooves. This process initiates the desertification cycle.
With no vegetation present, rain quickly drains off the land and does not replenish the groundwater.This makes the soil vulnerable to erosion. Almost one-third of rangeland in the world is degraded by overgrazing. Among the countries suffering severe range degradation are Pakistan, Sudan, Zambia, Somalia, Iraq, and Bolivia.
The United States has approximately 788 million acres of rangeland. This represents almost 34 percent of the land area in the nation. More than onehalf of the rangeland is privately owned, while approximately 43 percent is publicly owned and managed by the Forest Service and the Bureau of Land Management (BLM).
State and local governments manage the remaining 5 percent. Efforts to preserve rangelands include close monitoring of carrying capacity and removal of substandard ranges from the grazing cycle until they recover.
New grazing practices, such as cattle and sheep rotation, help to preserve the renewable quality of rangelands. Grazing is managed with consideration to season, moisture, and plant growth conditions. Noxious weed encroachment is controlled, and native forages and grasses are allowed to grow.
Most rangelands in the United States are short-grass prairies located in the western part of the nation. These lands are further characterized by thin soils and low annual precipitation. They undergo numerous environmental stresses. Woody shrubs, such as mesquite and prickly cactus, often invade and take over these rangelands as overgrazing or other degradation occurs.
Such areas are especially susceptible to desertification. Recreational vehicles, such as motorcycles, dune buggies, and four-wheel-drive trucks, can damage the vegetation on ranges. According to the 1993 Renewable Resource Assessment update, many of the rangelands in the United States were in unsatisfactory condition.
Steps to restore healthy rangelands include restoring and maintaining riparian areas and priority watersheds. These areas are monitored on a regular basis, and adjustments are made if their health is jeopardized by sediment from road use or degradation of important habitats caused by human activity.
The Natural Resources Conservation program is teaching private landowners how to burn unwanted woody plants on rangelands, reseed with perennial grasses that help hold water in the soil, and rotate grazing of cattle and sheep on rangelands so that the land is able to recover and thrive. Such methods have proven to be successful.