Unit 7

1. Type of forest that has not been seriously disturbed for several hundred years.
6. Removal of trees to clear space for agriculture, urbanization, or for timber
7. Type of fire where lots of undergrowth allows fire to burn very hot and spread quickly from tree top to tree top, most damaging
9. Prolonged period of consistently below average rainfall
10. Type of forest growth resulting from natural secondary succession
11. Parks and large areas of forest left in and around developments
12. Desalination by boiling water, capturing the steam, and allowing it to condense
14. Land degradation severe enough that land becomes desert, unable to support vegetation
16. When Cities fall apart, physically and socially, as people migrate to suburbs reducing city revenue generated from taxes.
17. low population density communities that are not directly connected to the metropolitan area

2. Large expanses of undeveloped land covered mostly with grasses or brush suitable for grazing livestock but too dry to farm
3. When usage exceeds the supply or poor quality of water makes it unusable for human needs
4. Removing salt from ocean water or brackish water to get fresh water
5. When the urban area expands outward into the rural surroundings and forms 2 types of communities
8. Type of fire that smolders underground burning up humus and soil microbes for days or weeks and are hard to put out.
13. Type of fire that only burns underbrush, little damage to mature trees, beneficial
15. Low population density areas outside the city