Chapter 23 Sustaining Ecosystems: Land Use, Conservation, and Management

How were land resources in the US used between the 1400’s and 1900’s? In the 1400’s to the 1500’s North America was populated with diverse groups of indigenous people who practiced mostly sustainable forms of hunting, gathering, and use of wild resources When European colonists settled they cleared the land, planted it, and exploited it for its resources as quickly as possible. They had no concern for waste because they believed there would always be more. The belief that North America’s resources were unlimited prevailed almost until 1900 when people started to become more concerned about environmental and public health hazards due to rapidly growing industrialized cities.

What role did the government play in resource conservation between 1900 and 1930? When Theodore Roosevelt became president he designated public land as wildlife refuges and tripled the size of forest reserves. In 1905 Congress created the US Forest Service to manage and protect the forest reserves The principle of sustainable yield and multiple use were employed In 1912 Congress created the US National Park System Between 1900 and 1927 public health boarders were established in most cities and governments started to pay more attention to issues pertaining to public health. In 1933 the Civilian Conservation Corps was formed to provide jobs for 2 million unemployed people by planting trees, developing parks and recreation areas, and protecting wildlife Federal government built and operated large dams, including Hoover Dam

Government’s role in resource conservation between 1930 and 1960 Taylor grazing Act of required permits and fees for the use of federal government lands and limited the number of livestock that could be grazed Migratory Bird Hunting Stamp Act of required that hunters buy duck hunting licenses raising millions for waterfowl research and the purchase of lands for wildlife refuges. Soil conservation Service of established to address soil erosion Federal Aid in Wildlife Restoration Act of raised more than 2.2 billion to buy land for wildlife conservation In 1940 US Fish and Wildlife Service was established Between 1933 and 1960 public health boards and agencies were established at the municipal state and federal levels. Education about health issues were emphasized.

Major Environmental Developments took place between 1960 and 1980 Rachel Carson published Silent Spring in 1962 pertaining to air, water, and wildlife pollution from pesticides, which brought the quality of air, water, soil, and wildlife to the public attention. In 1964 the Wilderness Act was passed by Congress, authorizing the government to protect undeveloped tracts of public land for the national good In 1976 the Federal land policy and Management Act gave the Bureau authority to manage public land Congress created the Department of Energy between 1977 and 1981 developing a long range energy plan, to reduce countries dependence on imported oil.

Ecological Integrity The goals of conservation biology are to investigate the human impact on biodiversity and to develop practical approaches to preserving biodiversity. Ecological Integrity – the conditions and natural processes that generate and maintain biodiversity and allow evolutionary change as a key mechanism for adapting the changes in environmental conditions. Ecological Health – described in terms of the degree to which its biodiversity and ecological integrity remain in tact. The scientific approach recognizes that saving wildlife means saving their habitats and not disturbing the complex interactions among species in an ecosystem.

U.S. Public Lands Multiple-use Lands: The 156 forest and 20 grasslands of the National Forest System are managed by the U.S. Forest Service. This land is supposed to be managed using two principles: sustainable yield and multiple use. Moderately Restricted-use Lands: The 508 National Wildlife Refuges are managed by the U.S. Fish and Wildlife Service and24% of this land is designated as wilderness. Most of these protect habitat and breeding areas for water fowl an big game to provide the harvestable supply for hunters; a few protect endangered species from extinction. Restricted-use Lands: The goals of the 375 units of the National Parks Systems are te preserve scenic and natural landscapes, preserve and interpret the country’s historic and cultural heritage, protect wildlife habitat and wilderness areas, and provide certain types of recreation.

Managing and Sustaining Rangelands Almost half of the earth’s ice-free land is rangeland: land that supplies vegetation for grazing animals and that is not intensively managed. About 42 % of the world’s range- land is used for grazing livestock; much of the rest is too dry, cold or remote from population centers to be grazed by large numbers of livestock. Rangeland provides forage for large numbers of large herbivores; provides habitats for a variety of wild plants and animal species

Overgrazing Overgrazing occurs when too many animals graze for too long and exceed the carrying capacity of the grassland area. It lowers the productivity of vegetation and changes the number and types of plants in an area Overgrazing is the major cause of desertification in arid and semi-arid lands. Heavy overgrazing compacts the soil, which diminishes its capacity to hold water and to regenerate itself.

Riparian Zones Riparian zones are thin strips of lush vegetation along streams These zones help prevent floods by storing and releasing water slowly from spring runoff and summer storms 65-75% of the wildlife in the western United States is totally dependent upon riparian habitats.

Rangeland Management The primary goal of rangeland management is to maximize livestock productivity without overgrazing rangeland vegetation. Stocking rate is the most widely-used method so that it does not exceed an area’s carrying capacity. Both the numbers and distribution of livestock on a rangeland must be controlled to prevent overgrazing. Continuous grazing occurs throughout the year and is popular because it is easy to manage and reduces costs by requiring little livestock handling and fencing. Deferred-rotation grazing involves moving livestock between two or more rangelands to allow perennial grass to recover from the effects of grazing.

Our National Parks Today, over 1,100 national parks larger than 2,500 hectares each are located in more than 120 countries. The U.S.National Parks System is dominated by 54 National Parks. Most State Parks are located near urban areas and thus are more heavily used than National Parks. Threats to the Parks: Popularity Noise Traffic hams Litter Vandalism Poaching Deteriorating trails Polluted water Garbage piles crime Increased number of roads, cars and annual recreational visits

Wilderness Protecting biodiversity and ecological integrity means protecting wildness. One way to do this is to protect undeveloped lands from exploitation by setting them aside as wilderness. A wilderness should contain at least 4,000 square kilometers, otherwise, if can be affected by air, water, and noise pollution from nearby human activities. Wilderness areas provide mostly undisturbed habitats for wildlife, plants and animals, protect diver biomes from damage and provide a laboratory in which we can discover more about how nature works.

Gap Analysis Gap analysis has been developed to determined how adequately native plants and animal species and natural communities are protected by the existing network of conservation lands. Species and communities not adequately represented in existing conservation lands constitute conservation gaps. The idea is to identify these gaps and then eliminate them in a proactive manner through the establishment of new reserves or changing land management practices.

Forest Types and Importance Three general types of forest: tropical, temperate and polar. Since agriculture began about 10,000 years ago, human activities have reduced the earth’s forest cover by abut one quarter. Old-growth forest: uncut forest and regenerated forest that have not been seriously disturbed for several hundreds or thousands of years. Second-growth forest: stands of trees resulting from secondary ecological succession after cutting Forest provide lumber for housing, biomass for fuel wood, pulp for paper, medicines, and other products. The U.S. is the world’s largest importer of wood products. Forests influence climate and are vital to the global carbon cycle.

Why Should we Care About Tropical Forests? The plight of tropical forests is considered one of the most serious environmental problems because these forests are home to 50-90% of the earth’s terrestrial species. These forests supply one- half of the world’s annual harvest of hardwood, hundreds of food products, and materials such as natural latex, (rubber), and essential oils. 25% of the worlds prescription drugs are derived from plants that grow in tropical rainforests 70 % of the 3,000 plants identified as sources of cancer-fighting chemicals come from these forests.

Fuelwood Crisis and Developing Countries In 1998, about 2.2 billion people in 63 developing countries either could not get enough fuelwood to meet their basic needs, or were forced to meet their needs by using wood faster than it was being replenished. As burning wood to boil water becomes an unaffordable luxury, waterborne infectious diseases and death will spread. Buying fuelwood can take 40% of a poor family’s meager income. By burning dried animal dung and crop residues for cooking and heating, these fertizers never each the soil, and cropland productivity is reduced creating degradation in the land and further malnutrition and hunger. Fuelwood shortages are driven by rapid population growth and poverty.

23: Managing and Sustaining Forests About 25% of the world’s forests are managed for wood production. The total volume of wood produced by a particular stand of forest varies as it goes through different stages of growth and ecological succession. Two Basic Forest Management Systems: 1. Even-aged management: trees in a given stand are maintained at about the same age and size 2. Uneven-aged management: a variety of tree species in a given stand are maintained at many ages and sizes to foster natural regeneration

How are Trees Harvested? Selective cutting- intermediate-aged or mature trees in an uneven-aged forest are cut singly or in small groups, creating gaps no larger than the height of standing trees, which encourages the growth of younger trees and reduces crowding Shelter-wood cutting- removes all mature trees in two or typically three cuttings over a period of about 10 years. Seed-tree cutting- harvests nearly all of a stand’s trees in one cutting, leaving a few uniformly distributed seed-producing trees to regenerate the stand. (used for recreation)

Continued… Clear-cutting- Removal of all trees from an area in a single cutting. The clear-cut area may be a whole stand, a strip, or a series of patches. After all the trees are cut, the site is usually reforested Strip cutting- A variation of clear-cutting that can allow a sustainable timber yield without widespread destruction Whole-tree harvesting- machine cuts trees at ground level or uproots entire trees. These trees are transported to a chipping machine in which huge blades reduce the woods to small chips.

How Fires Affect Forest Ecosystems Surface fires- burn only undergrowth and leaf litter on the forest floor. These fires kill seedlings and small trees, but spare most mature trees Crown fires- start on the ground but eventually burn whole trees and leap from treetop to treetop. They destroy vegetation, kill wildlife, lead to accelerated soil erosion, and set back the clock of ecological recovery by up to hundreds of years. Prescribed burning- controlled ground fires to prevent buildup of flammable material

23: Solutions: Reducing Tropical Deforestation and Fuelwood Shortages Conservation biologists urge us to move rapidly to protect areas of tropical forests that are rich in unique species and in imminent danger- hot spots/ critical ecosystems Environmentalists urge governments to reduce the flow of the landless poor to tropical forests by slowing population growth and discouraging the poor from migrating to undisturbed tropical forests Another suggestion is to use economic policies to protect and sustain tropical forests- full-cost pricing, debt-for-nature

22: Why Preserve Wild Species? The Values of Species (6) Economic Medical Scientific Ecological Aesthetic Recreational

The Economic and Medical Importance 90% of today’s food crops were domesticated from wild tropical plants Wild plants domesticated from wild species supply rubber, oil, dyes, fiber, paper, and lumber 80% of the world’s population relies on plants or plant extracts for medicines 40% of all pharmaceuticals, worth at least $100 billion per year, owe their existence to the genetic resources of wild plants, mostly from tropical developing countries

The Scientific and Ecological Importance Every species can help scientists understand how life has evolved and functions, and how it will continue to evolve on this planet. Wild species supply us with food, recycle nutrients to the agriculture, and help generate and maintain soils. They also produce oxygen and other gases, absorb late climates and water supplies, reduce erosion and flooding, and store solar energy.

Aesthetic and Recreational Importance Americans spend about $18.2 billion a year to watch wildlife Ecotourism- Wildlife Tourism- is the fastest growing segment of the global travel industry and generates an estimated $30 billion in revenues each year.

22: The Rise and Fall of Species 99.9% of all the species that have ever existed are no extinct because of a combination of background and mass extinction. Background- A small number of species becoming extinct at a low rate every year. Mass Extinction- Abrupt rise in extinction rates above the background level. The lass mass extinction took place 65 million years ago when the dinosaurs became extinct for reasons that are hotly debated.

Is There and New Mass Extinction Crisis? Currently 18,000-73,000 species become extinct each year (natural background extinction rate 3-30 per year) Three differences between the current mass extinction and those of the past 1. The current extinction crisis is the first to be caused by a single species: humans 2. The current mass wildlife extinction is taking place in only a few decades, rather than over thousands to millions of years.

Continued.. 3. Besides killing off species, we are eliminating many biologically diverse environmentalists such as tropical forests, tropical coral reefs, wetlands, and estuaries that in the past have served as evolutionary centers for the recovery of biodiversity after a mass extinction

Endangered and Threatened Species Three Levels of Extinction: 1. Local extinction occurs when a species is no longer found in an area it once inhabited but is still found elsewhere 2. Ecological extinction occurs when there are so few members of a species left that it can no longer play its ecological roles in the biological communities where it is found 3. Biological extinction occurs when a species is no longer found anywhere on the earth.

Threatened Species American Alligator Bald Eagle Giant Panda

Continued… Endangered Species: has so few survivors that the species could soon become extinct over all or most of its natural range. (Example- Giant Panda in central China) Threatened Species: Still abundant in the natural range but is declining in numbers and is likely to become endangered. (Example- Grizzly Bear)

Characteristics of Extinction-Prone Species: Low reproductive rate Specialized feeding habits Feed at high trophic levels Large size Limited or specialized nesting or breeding areas Found in only one place or region Fixed migratory patterns Preys on livestock or people Behavioral Patterns

Extinct Species Dodo Great Auk Passenger Pigeon

22: Causes of Depletion and Premature Extinction of Wild Species 1. Human population growth 2. Economic systems and policies that fail to value the environment and its ecological services 3. Greater per capita resource use as a result of increasing affluence and economic growth

Underlying Causes Lead to other more direct causes of endangerment and extinction of wild species such as… 1. Habitat loss and degradation 2. Habitat fragmentation 3. Commercial hunting and poaching 4. Over fishing 5. Predator and pest control 6. Sale of exotic pets and decorative plants 7. Climate change and pollution 8. Deliberate or accidental introduction of nonnative species into ecosystems.

22: Solutions: Protecting Wild Species from Depletion and Extinction Three approaches to managing wildlife and protecting biodiversity. Ecosystem approach- aims to preserve balanced populations of species in their native habitats, establish legally protected wilderness areas and wildlife reserves, and eliminate or reduce the populations of nonnative species

Continued… Species approach- based on protecting endangered species by identifying them, giving them legal protection, preserving and managing their crucial habitats, propagating them in captivity, and reintroducing them into suitable habitats.

Continued… Wildlife management approach- manages game species for sustained yield by using laws to regulate hunting, establishing harvest quotas, developing population management plans, and using international treaties to protect migrating game species.

Endangered Species Act The Endangered Species Act of 1973 is one of the world’s toughest environmental laws. It authorizes the National Marine Fisheries Service to identify and list endangered and threatened ocean species; the U.S. Fish and Wildlife Service identifies and lists all other endangered and threatened species. These species cannot be hunted, killed, collected or injured in the United States.

Rules and Regulations… Any decision by either agency to add or remove a species from the list must be based on biology only. The act forbids federal agencies to carry out, fund, or authorize projects that would either jeopardize an endangered species or destroy or modify the critical habit it needs to survive. Between 1973 and 1998, the number of U.S. species included in the official endangered and threatened species list increased from 92 to over 1,100 species. (Highest State- Hawaii)

Continued… The USFWS or NMFS is supposed to prepare a plan to help the species recover. The act requires that all commercial shipments of wildlife and wildlife products enter or leave the country through one of nine designated ports.

22: Wildlife Management Wildlife management entails manipulating wildlife populations and their habitats for their welfare and for human benefit. It includes preserving endangered and threatened wild species and enforcing wildlife laws. The first step in wildlife management is to decide which species are to be managed in particular area, a decision that is a source of much controversy. After goals have been set, the wildlife manager must develop a management plan. Ideally, this is based on the principles of ecological succession, wildlife population dynamics, and an understanding of the cover, food, water, space, and habitat requirements of each species.

24: Fishery Management and Protecting Marine Biodiversity Freshwater: This involves encouraging populations of commercial and sport fish species and reducing or eliminating populations of less desirable species. Techniques include regulating time and length of fishing seasons and the number and size of fish that can be taken Marine Fisheries: Set annual quotas and establish rules for dividing the allowable catch among the participating countries or state, limiting fishing seasons, and regulating the type of fishing gear that can be used to harvest a particular species.

24: The Whaling Industry Cetaceans- an order of mostly marine mammals ranging in size from.9 to 30 meters. They are divided into two groups: Toothed Whales (bite their foods) and Baleen Whales (filter feeders) Whales are easy to kill because of their large size and their need to come to the surface to breathe. The Blue Whale has come to the brink of biological extinction. It is the largest animal in the world today.

Whales- The Blue Whale and the Humpback…

Whales Continued… Sperm Whale