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Transcript of Chapter 10:
Land, Public and Private
Read pg 261: Who Owns a Tree?
Human Land Use Affects the Environment in Many Ways
Public Lands are Classified According to Their Use
Land Management Practices Vary According to Land Use
Negative Consequences of Land Use
(1) Deforestation & mudslides through extensive logging
(2) Rerouting water runoff by paving over land surfaces
(3) Soil degradation & water pollution due to overuse of farmland
Tragedy of the Commons
1968: Garrett Hardin described the tragedy of the commons: the tendency of a shared, limited resource to become depleted because people act from self-interest for short-term gain.
The costs of benefits of goods or services that are not included in the purchase price of those goods or services.
Ex. Smelling of freshly baked bread near a bakery = positive externality
Negative externalities lead to serious environmental damage for which no one is held legally or financially responsible.
Ex. Farmer grazing too many sheep in a common pasture
Solutions: (1) Private ownership (2) Regulation
Maximum Sustainable Yield
When we want to obtain the maximum amount of a resource, we need to know how much of a given plant or animal population can be harvested without harming the resource as a whole.
Ex. Deer hunting
The intermediate harvest is called the maximum sustainable yield (MSY)-varies case by case, but a reasonable starting point is to assume that population growth is fastest at about one-half the carrying capacity of the environment.
MSY is the amount of harvest that keeps the resource population at that level (1/2 K).
**Tragedy of the Commons Lab-see handout for details.
2003 United Nations List of Protected Areas
Only 4.2 billion acres of land are protected of the 37 billion acres of land (11%, or 1/9th of Earth's land area).
International Categories of Public Lands:
Managed Resource Protected Areas
Habitat/Species Management Areas
Strict Nature Reserves & Wilderness Areas
Protected Landscapes & Seascapes
Public Lands in the United States
Federally, State or Locally owned lands = 42%
Public Land Classifications
Rangelands, national forests, national parks, national wildlife refuges, & wilderness areas
Resource Conservation Ethic
Land use and federal agencies
BLM-grazing, mining, timber harvesting, and recreation
USFS-timber harvesting, grazing, and recreation
NPS-recreation and conservation
FWS-wildlife conservation, hunting, and recreation
1. Why do humans value land?
2. What is the tragedy of the commons?
3.What are the main uses of public lands in the U. S.?
4. How do human land use decisions influence categories of public land classification?
Description: dry, open grasslands susceptible to fires and other environmental disturbances
Use: primarily for cattle grazing- Environmental benefit= ungulates can be raised on lands that are too dry for farming and cheaper than feedlots; Environmental cost=damage to stream banks and surface waters, loss of vegetation-->erosion
The Taylor Grazing Act of 1934 designed to put a halt to overgrazing by limiting the number of animals to prevent a tragedy of the commons
BLM (Bureau of Land Management) does not however, require the involvement of environmental scientists and regulations are limited and ineffective as a result.
Description: dominated by trees and other woody vegetation
Use: 73% of forests in the U. S. are commercial timber operations and privately owned & U. S. National Forests do allow commercial logging to use their land and timber for a royalty
Timber harvest practices: clear-cutting, selective cutting, & ecologically sustainable forestry
Fire management-->prescribed burns
National Parks and Wildlife Refuges & Wilderness Areas
NPs: Managed for scientific, educational, aesthetic, and recreational use.
The NPS manages 391 parks and other areas such as historical parks and national monuments.
(1) protect ecosystems through conservation and wildlife protection
(2)maintain multiple-use principle
(3) reducing human impact within the boundaries of the park
WFs: managed for the primary purpose of protecting wildlife.
The Fish and Wildlife Service manages 450 national wildlife refuges and 28 waterfowl production areas.
National Wilderness Area Goals:
(1) preserving large tracts of intact ecosystems or landscapes
Regulation? NEPA-->Clean Air Act, Clean Water Act, & Endangered Species Act
An EIS must be approved before a project can begin and an environmental mitigation plan must be approved