Chapter 8 Answers

Chapter 8 - Sustaining Biodiversity: The Ecosystem Approach

1. Five Types of Public Lands in the United States:
- National Forest System: used for logging, mining, livestock grazing, farming, oil and gas extraction, recreation, hunting, fishing, and conservation of watershed, soil, and wildlife resources. The U.S. Forest Service (USFS) manages its 155 forests and 22 grasslands.
- National Resource Lands: managed by the Bureau of Land Management (BLM) and is used for mining, oil and gas extraction, and livestock grazing.
- National Wildlife Refuges: managed by the U.S. Fish and Wildlife Service (USFWS) which protect habitats and breeding areas for waterfowl and big game. Some protect endangered species from extinction. Hunting, trapping, fishing, oil and gas development, mining, logging, grazing, some military activities, and farming are permitted.
- National Park System: camping, hiking, sport fishing and boating are allowed in the national parks, while sport hunting, mining, and oil and gas extractions are allowed in national recreation areas. It’s managed by the National Park Service (NPS).
- National Wilderness Preservation System: roadless areas in national parks, national wildlife refuges, national forests, and national resource lands that are managed by the agencies in charge of the area.

2. Old-growth: uncut or regenerated forest that hasn’t been seriously disrupted for at least several hundred years. They provide ecological niches for wildlife species.
Second-growth: trees resulting from second succession and develop after trees have been removed by human activities or natural forces.

3. Even-aged management: trees are maintained at the same age and size. They consist of one or two fast growing and desirable species, usually for industrial forestry.
Uneven-aged management: variety of species with a range of ages and sizes. The goals are biological diversity and sustainable production of high-quality timber.
Five Types of Tree Harvesting:
- Selective cutting: intermediate-aged or mature trees in an uneven-aged forest.
- Shelterwood cutting: even-aged forests
- Seed-tree cutting: even-aged forests
- Clear-cutting: all trees are removed in one cut; even-aged forest
- Stip cutting: clear cutting a strip of trees

4. Strategies for Protecting Forests:
- Prescribed burning: allow small fires in National Parks, forests, and wilderness to burn, and defensible space
Industrial forestry: trees are grown for industrial purposes and replaces biologically diverse forests, similar to a tree plantation.
Sustainable forestry: balance between the society’s demands of forest products and the preservation of the forest.

5. Current State of Old-Growth Forests in the U.S. and Canada:
- they are in bad condition
- the old-growth forests are declining as the second growths are beginning
Steps That Would Help Reform Federal Forest Management:
- conserve biodiversity along with water and soil resources
- grow more timber on long rotations
-rely more on selective cutting and strip cutting
- no clear-cutting, seed-tree, or shelterwood cutting on steeply sloped land
- no fragmentation of remaining large blocks of forest
- sharply reduce road building into uncut forest areas
- leave most standing dead trees and fallen timber for wildlife habitat and nutrient recycling
- certify timber grown by sustainable methods
- include ecological services of trees and forests in estimating economic value

6. Tropical Forests:
- cover about 6% of earth’s land area, but once covered at least twice as much as today
- rapid and increasing deforestation- for crop lands, logging, and ranching.
- loss of biodiversity- half of terrestrial plants and animals live in tropical forests
- underlying causes: not valuing ecological services, exports, government policies, poverty, population growth
- direct causes: oil drilling, mining, flooding from dams, tree plantations, cattle ranching, cash crops, settler farming, fires, logging, roads
- can preserve tropical forests by teaching settlers in the forest how to practice small-scale sustainable farming, by sustainably harvesting the forest's renewable resources (fruit, nuts), by offering countries foreign aid/debt relief if they protect their forest reserves, by using gentler methods for harvesting trees, and by increasing efforts to reforest and rehabilitate degraded tropical forests.

7. The Firewood Crisis:
- nearly half the people on earth may be a little colder and hungrier as population increases and forest land is converted to other use
- firewood is a cheap source of fuel for cooking and heating
- it's a vicious cycle: as forests disappear, those who rely on them begin eating away at other forests, perpetuation the problem
- we can develop alternative energy sources and then protect the remaining forests using some of the methods discussed above in question 6.

8. Rangelands: national parks/wilderness areas:
National Parks:
- 1,100 national parks, but most are threatened by human activities
- popularity is a big problem in the parks as there is an increase in noise, congestion, eroded trails, and stress. To manage the problem, there could be a limit to the number of visitors to the crowded park areas.
Wilderness Areas:
- land set aside in a large area to prevent of minimize harm from human activities. It’s one way to protect undeveloped land.
- most protected areas are small but many public lands could qualify as wilderness; therefore, more should be considered for wilderness protection

9. Establishment of Nature Reserves:
- only 12% of earth's ecosystems are untouched; only 5% of those areas are protected
- conservation biologists call for full protection of at least 20% of earth's land that include multiple examples of all the different biomes, not just desert, tundra and ice (what the 12% mostly consists of now)
- conservation biologists use the buffer zone concept to design and manage nature reserves, protecting an inner core of the reserve by establishing two buffer zones so local people can extract resources sustainable. It won’t harm the inner core and it will protect a nature reserve from unsustainable uses.

10. Issues Involved in Protecting the Marine Environment:
- rapidly growing coastal development and accompanying massive input of sediment and other waste has harmed shore-hugging species and threatens the coastal ecosystem.
- a lot of the damage to the ocean and other bodies of water are not visible to people; therefore, people think that the bodies of water are inexhaustible resources that can absorb large amounts of pollution and waste.
- world’s ocean area lies outside the legal jurisdiction of any country. It is an open access resource that can be over exploited because of the tragedy of the commons.

(Britney Lee, 5th Period) (questions 6, 7, 8, 9 added to by Erin Gravley, 5th period)
(I've worked on some of these questions, although it seems that Erin and Britney have them all. Their answers are solid, so I won't mess around with them. I can show some of the work I've done if you'd like, though. - Christopher Anderson, 5th)

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