1. Unit VI
Land Use

2. Land Breakdown

3. US Land Use 55% of land in US is privately owned
Remaining land is owned by the government
Most federal land is in Alaska and western states

4. Land Use

5. Wilderness Parks and Wildlife Refuges
A protected area
of land in which no
human development
is permitted
Wilderness Act
(1964)
Set aside federally owned land
Managed by NPS, USFS, FWS & BLM

6. National Parks 1st Park 1872 National Park Service
Yellowstone
National Park Service
Created in 1916
Currently includes 58 parks
Primary goal
Teach people about the natural environment, management of natural resources and history of a site

7. National Parks Threats to U.S. Parks Natural Regulation
Crime & Vandalism
Traffic jams
Pollution of the soil, water and air
Resource violations
Natural Regulation
Policy to let nature take its course
No culling wildlife or suppressing wildfire

8. Wildlife Refuge National Wildlife Refuge System
First one in 1870
Lake Merritt, CA
First National 1903
Pelican Island
Represent all major ecosystems found in the US
Mission
To preserve lands and waters for the conservation of fishes, wildlife and plants of the US

9. National Forests Managed for multiple uses Road building is an issue
Timber harvest
Livestock forage
Water resource and watershed protection
Mining, hunting, fishing, etc.
Road building is an issue
Provides logging companies with access to forest
Clearcutting is an issue

10. Forest Management Traditional Forest Management
Low diversity - monocultures
Managed for timber production

11. Forest Management Ecological Sustainable Forest Management
Environmentally balanced
Diverse trees
Prevent soil erosion
Preserve watersheds
Wildlife corridors - unlogged

12. Harvesting Trees

13. Deforestation Results of Deforestation Decreased soil fertility
Uncontrolled soil erosion
Production of hydroelectric power (silt build up behind dams)
Increased sedimentation of waterways
Formation of deserts
Extinction of species
Global climate changes

14. Rangelands Rangelands
Land that is not intensively managed and is used for grazing livestock

15. Rangelands Overgrazing leaves ground barren Land degradation
Animals exceed land’s carrying capacity
Land degradation
Natural or human-induced process that decreases future ability of land to support crops or livestock
Desertification
Degradation of once fertile land into nonproductive desert

16. Rangelands Make up 30% of total US land area
Pressure from developers to subdivide
Public rangeland managed by:
Taylor Grazing Act (1934)
Federal Land Policy and Management Act (1976)
Conditions of public rangeland are slowly improving

17. Agricultural Land US has 300 million acres of prime farmland
Suburban sprawl
Parking lots
Housing
developments
Shopping malls

18. Food Production Methods
Croplands
provides ~75% of world’s food supply
mostly grain production
Rangelands
provides ~15% of world’s food supply
includes meat and meat products
Fisheries
provides ~7% of world’s food supply
primarily oceanic fishes

19. World Food Security Feeding growing population is difficult
Annual grain production (left) has increased since 1970
Grain per person has not (right)

20. Crop Production

21. Animals as Food
Constitute 40% of the calories consumed in developed countries
Only comprise 5% of calories consumed in developing countries

22. Principle Types of Agriculture
Industrialized agriculture
Modern agriculture methods that require large capital input, and less land and labor
Uses large amounts of energy, water, fertilizers, & pesticides
practiced on ~25% of all cropland
produces ~80% of world’s food supplies

23. Principle Types of Agriculture
Subsistence Agriculture
Traditional agricultural methods, which are dependent on labor and large amounts of land
Most common type of agricultural practice
practiced by ~40% of world’s population
shifting cultivation, slash and burn agriculture, nomadic herding, intercropping

24. Challenges of Producing More Crop and Livestock
Domestication and Genetic Diversity
Domestication of crops and livestock causes a loss of genetic diversity
Farmer selects and propagates animals with desirable agricultural characteristics

25. Challenges of Producing More Crop and Livestock
Increasing Crop Yields
Food production increased in developed countries (wheat(left)
Pesticides
Selective breeding

26. Challenges of Producing More Crop and Livestock
Increasing Livestock Yields
Hormone supplements
US and Canada
Not used in Europe
Antibiotics
40% of antibiotics produced in US are used in livestock operations
Problems with increased bacteria resistance

27. Antibiotic Use and Resistance

28. Genetic Engineering
Manipulation of genes by taking specific gene from a cell of one species and placing it into the cell of an unrelated species

29. Genetically Modified Organisms (GMOs)
Add beneficial characteristics to crops
Additional nutrition
Resistance to pests
Drought resistances (below)
Herbicides

30. Genetically Modified Organisms (GMOs)

31. Safety in Genetic Engineering
Studies have shown them to be safe for human consumption
Concerns about GMO seed or pollen spreading in wild
GMOs are not currently labeled
Push for legislation in certain states or communities
Backlash against GMOs
Banned in EU

32. Environmental Impacts of Agriculture

33. Sustainable Agriculture
Examples:
Natural Predator-prey relationships instead of pesticides
Crop selection
Crop rotation and conservation tillage
Supplying nitrogen with legumes
Organic agriculture
Integrated Pest Management (IPM)

34. Fisheries No nation lays claim to open ocean
Resource susceptible to overuse and degradation
commons

35. Fisheries Overharvesting Many species are at point of severe depletion
62% of world’s fish stock are in need of management action
Sophisticated fishing equipment
Bycatch killed off

36. Commercial Fishing Methods
Trawling
Purse-Seine
Longlining
Drift Net
Aquaculture

37. World Seafood Harvest

38. Fisheries of the World - Problems
Ocean Pollution - dumping ground
Oil
Heavy metals
Deliberate litter dumping
Stormwater runoff from cities and agricultural areas
Aquaculture
Growing of aquatic organisms for human consumption
Great potential to supply food

39. Fisheries of the World - Problems
Aquaculture (continued)
Locations of fisheries may hurt natural habitats
Produce waste that pollutes adjacent water

40. Pesticides Broad spectrum pesticide 1st Generation Pesticide
A pesticide that kills a variety of organisms, not just the targeted organisms
1st Generation Pesticide
Inorganic compounds
Botanicals: plant derived pesticides (right)

41. Pesticides
Second generation pesticide
Synthetic poison
Ex: DDT

42. Problems with Pesticides
Evolution of Genetic Resistance
Pest populations are evolving resistance to pesticides (right)

43. Pesticide Resistance Pesticide Treadmill Resistance Management
Cost of applying pesticide increases
While their effectiveness decreases
Resistance Management
Strategies for managing genetic resistance in order to maximize the period in which a pesticide is useful

44. Problems with Pesticides
Imbalances the Ecosystem
Spraying to kill insects can affect birds, rabbits, etc.
Despite 33-fold increase in pesticides since the 1940s, crop loss has not decreased much

45. Problems with Pesticides
Persistence, Bioaccumulation, and Biomagnification
Bioaccumulation: The buildup of a persistent pesticide or other toxic substance in an organisms body
Biomagnication: Increased concentration of toxic chemicals in tissues of organisms at higher trophic levels

46. Systems Approach - Integrated Pest Management (IPM)
Combination of pest control methods that keeps pest population low without economic loss
Conventional pesticides are used sparingly when other methods fail

47. Integrated Pest Management

48. Systems Approach - Integrated Pest Management (IPM)
Rice Production in Indonesia

49. Manufacture and Use of Banned Pesticides
Some US companies still make banned or seriously restricted pesticides
Product is exported
May lead to the importation of food tainted with banned pesticides
Global ban of persistent organic pollutants
Stockholm Convention on Persistent Organic Pollutants POPS (2004)

50. Manufacture and Use of Banned Pesticides - The Dirty Dozen

51. International Regulations
Endangered Species Act- prohibits the harm or harvesting of endangered species; protects habitats
Marine Mammal Protection Act- protection and conservation of marine mammals (whales, dolphins, etc)