1. Chap. 14 Land
Mrs. Brown
Feb.7th, 2019

2. Land use & Land cover
Land is used for many purposes: farming, mining, recreation, cities, etc.
Urban land – land mainly covered with buildings & roads
An urban cluster has at least 2,500 people & a governing body
Rural land – land that contains very few people & large areas of open space
Until 1850 majority of people lived in rural areas (farming, forestry, & mills)
Industrial Revolution introduced machinery (needing less farm & mill workers) & improved transportation
People had to move to cities to find jobs

3. Urban-Rural connection
People depend on resources produced in rural areas: clean drinking water, fertile soil, land for crops, trees for wood & paper, & the oxygen we breathe
Ecosystem services: resources that are produced by natural & artificial ecosystems
Well planned urban areas:
1. Well designed roads & public transportation to handle traffic flow
2. Buildings & paved areas mixed in with green spaces & rec areas (temperature moderation, infiltration of rainwater runoff, & aesthetic value)

4. urbanization
Urbanization – movement of people from rural areas to cities
More plentiful and better paying jobs in towns and cities.
79% of the US population is classified as urban
Metropolitan areas: many smaller towns/cities come together to form larger urban areas
Ex. Atlanta Metro or Washington D.C.-Baltimore

5. Urban crisis
Rapidly growing population can overwhelm the infrastructure
Lead to traffic jams, substandard housing, & polluted air and water
Infrastructure - all of the things that a society builds for public use
Infrastructure includes roads, sewers, railroads, bridges, canals, fire and police stations, schools, libraries, hospitals, water mains, and power lines.
Urban crisis - more people live in a city than infrastructure can support; the living conditions deteriorate.

6. Urban sprawl
Urban sprawl - rapid expansion of a city into the countryside around the city
From building housing & commercial buildings on a larger town boundary
People living in the suburbs usually commute to work in the city by car
Many suburbs are built on land that was previously used for food production
Each year suburbs spread over another 2.5 million acres of land in the US

7. Development & Impacts
As the cities grew, suburbs were often built on marginal land—land that is poorly suited for building.
Examples: homes built where slopes are = prone to land slides or erosion
Can become difficult or impossible to repair & can be expensive to insure
Cities both generate & trap more heat (roads/buildings absorb & retain more heat)
Heat island - increased temperature in a city is called a heat island (ex. Atlanta, Georgia)
Can affect local weather patterns; hot air rises over a city, cooling as it rises producing rain clouds.
Can try planting trees for shade or installing rooftops that reflect heat

8. Urban planning
Land Use Planning - determining in advance how land will be used (best locations are for houses, businesses, and factories, and where recreational land or infrastructure should be placed)
Developers prepare detailed reports assessing the environmental impact of many projects
People often disagree about land-use plans
Geographic Information System (GIS) - computerized system for storing, manipulating, and viewing geographic data
Enter different types of data about an area (like location of sewer lines, roads, & parks) & create maps
Used to understanding habitat requirements of species, patterns of pollutant spread, etc.

9. Urban planning cont.
Most cities in US are difficult to travel in without a car vs. most cities in Europe were built before cars (have narrow roads)
Mass transit systems use buses & trains to move many people at one time.
Save energy, reduce highway congestion, reduce air pollution, & limit the loss of land to roadways & parking lots
Carpooling is also an important alternative.

10. Open space
Open space - land that is set aside for agriculture or scenic and recreational enjoyment
Includes parks, public gardens, & bicycle and hiking trails
Greenbelts - open spaces left in their natural condition
Plants absorb CO2, produce O2, filter out air & water pollutants from air and water, & help keep a city cooler in summer.
Provide food resources, reduce drainage problems by absorbing rainwater runoff
Provide urban dwellers with places for exercise and relaxation

11. farmlands Farmland - land that is used to grow crops
US has more than 100 million hectares of prime farmland
Urban development threatens some of the most productive farmland
1996: US government established a Farmland Protection Program to help state, county, & local governments protect farmland in danger of being paved over or developed

12. Rangelands
Rangeland - land that supports different vegetation types like grasslands, shrublands, & deserts (not used for farming or timber)
Rangelands can be arid or wet
Most commonly used for the grazing of livestock (cattle, sheep, & goats valued for meat, milk, wool, and hides)
Essential for maintaining the world’s food supply
Some are becoming degraded by poor land management strategies; most damage from overgrazing (allowing more animals to graze in an area than the range can support)
Can result in changes in the plant community; less desirable plant species may invade the area

13. Rangelands Cont.
If all the vegetation is eaten, nothing stops soil from eroding
Much US rangeland is public land managed by the federal government, which leases the much degraded land to ranchers
Public Rangelands Improvement Act of 1978 was enacted to reverse this trend & improve land management practices
Sustaining the productivity of rangeland:
Limiting herds to sizes that do not degrade the land
Leave land unused for periods so vegetation can recover
Killing invasive plants, planting native vegetation, and fencing areas
Providing several small water sources so livestock do not overgraze in one spot

14. Forest lands Trees needed for paper, furniture, lumber, food, etc.
Important for removal of CO2 from the air (carbon sequestration)
Each person in the US uses a 30 m tall tree every year
1.5 billion people in developing countries depend on firewood as main source of fuel
Types of forests:
Virgin forest - forest that has never been cut
Native forest - forest that is planted and managed
Tree farms - which are areas where trees are planted in rows and harvested like other crops

15. Forestland continued
Clear-cutting - process of removing all or most of the trees from an area of land.
Sometimes a few “seed trees” are left behind to help regrow the area or provide wildlife habitat.
Can change or destroy wildlife habitat & cause soil erosion
Selective cutting - process of cutting and removing only certain trees, leaving the rest.
More expensive but less destructive method (can improve the health of the forest)

16. deforestation
Deforestation - the clearing of trees from an area without replacing them
Cleared to convert the land into farmland or make space for roads, homes, factories, & office buildings
Reduces wildlife habitat
Soil is easily washed or blown into valleys below when cleared
Hundreds of farmers bankrupt during Great Depression; the state bought many of the abandoned farms & let the forests regenerate
Deforestation highest in rainforests (thin soil); if farming not done sustainably, more forest is cleared due to used up nutrients
If trees are not replanted, natural resources are steadily depleted

17. reforestation
Clear-cut forest can be replanted or allowed to regrow naturally
Reforestation - the process by which trees are planted to re-establish trees that have been cut down in a forest
Big Thicket in Texas was heavily logged in 1900s. Bought by governments during the Great Depression and made into 1st National Preserve.
90% of timber from forests that are not sustainably managed
Many governments working to improve reforestation efforts & promote less destructive logging methods
Some private organizations have established tree-planting programs

18. Parks and preserves US has about 50 national parks (protected land)
Some public lands leased to private companies for logging, mining, & ranching
Some public lands maintained for hunting & fishing (wildlife refuges) or for protecting endangered species
United Nations’ Man and the Biosphere Program - has set up several hundred preserves throughout the world (biosphere reserves)

19. wilderness
U.S. Wilderness Act designated certain lands as wilderness areas
Wilderness - an area where land & the ecosystems it supports are protected from all exploitation
474 regions in US are designated as wilderness
Wilderness areas are open to hiking, fishing, boating (without motors), and camping
No building roads or structures and using motorized equipment

20. Benefits & Threats to Protected Areas
Protected areas & preserves have saved some species from extinction
Also provide recreation for people, serve as outdoor classrooms & research labs
People over-visiting national parks leads to increased litter and traffic jams
Urban areas (fossil fuels, mining, etc.) are near enough to the parks to affect their health
Preserved areas are affected by climate change & air and water pollution
Conservation organizations maintain preserves & protect local ecosystems to promote ecotourism
1700 private land trusts protect over 37 million acres of US land