1. occurs when only a few individuals in a population survive catastrophic events, and then the population lacks genetic diversity

2.
-temperature increase with height due to gamma rays, X rays, and UV radiation
-molecules are converted into ions
-causes Northern lights

3. • Waste less water and subsidize water conservation
• Do not deplete aquifers
• Preserve water quality
• Protect forests, wetlands, mountain glaciers, watersheds, and other natural systems
• Get agreements among regions and countries sharing surface water resources
• Raise water prices
• Slow population growth

4.
• deep open water where it is too dark for photosynthesis
• without sunlight and plants, oxygen levels are low

5.
Found near the western coast of North America. Where the Pacific and North American plates move relative to each other.

6. a soil degradation process caused by repeated annual application of irrigation water in dry climates, which leads to the gradual accumulation of salts in the upper soil layers

7.
Extends from surface of Earth down to 20-30 miles. Continental crust (granite) is less dense then ocean crust (basalt).

8. no nutrients in lakes

9. • Waste less water
• Subsidize water conservation
• Limit number of wells
• Do not grow water-intensive crops in dry areas • Raise price of water to discourage waste
• Tax water pumped from wells near surface waters
• Set and enforce minimum stream flow levels
• Divert surface water in wet years to recharge aquifers

10.
• littoral zone
• limnetic zone
• photic zone
• profundal zone
• benthic zone
(some zones are also applicable to oceans)

11.
cattle are confined by portable fencing to one area for a short time and then moved to a new location

12. • Tectonic plates- locations of continents and oceanic basins greatly influence the earth's climate and movement of continents spread animals to new places (new resources)
• Earthquakes- disruptions in earth's crust that can isolate species
• Volcanic eruptions- can reduce or wipe out populations
• Natural catastrophes

13. loss of native vegetation; increased wind erosion; salinization; drop in water table; reduced surface water supply

14. • Aquifer depletion from overpumping
• Sinking of land (subsidence) from overpumping
• Aquifers polluted for decades or centuries
• Saltwater intrusion into drinking water supplies near coastal areas
• Reduced water flows into surface waters
• Increased cost & contamination from deeper wells

15. the reduction of a species to such low abundance that, although it is still present in the community, it no longer interacts significantly with other species

16. • strong hydrogen bonds
• high specific heat
• high boiling point
• needs a lot of energy to evaporate
• expands when freezes

17.
uses pumps to spray water on a crop; results in a series of circular irrigated areas; 80% of water reaches crops

18. • The greatest marine biodiversity occurs in coral reefs, estuaries, and the deep-ocean floor
• Biodiversity if higher near coasts than in the open sea because of the great variety of producers and habitats in coastal areas
• Biodiversity is higher in the bottom region of the ocean than in the surface region because of the great variety of habitats and food sources on the bottom

19.
a rich dark brown

20. • dams and canals fragment natural biodiversity and destroy wildlife
• cities and farms add pollutants and excess plant nutrients

21.
Caused by friction and stress buildup from the sliding plates, a common feature along transform boundaries.

e.g. Haiti Earthquake 2010

22. absence of grazing for long periods can reduce the net primary productivity of grassland vegetation and grass cover

23. the number of different species a community contains (species richness) combined with the relative abundance of individuals within each of those species (species evenness)

24.
role in shaping communities by creating and enhancing their habitats in way that benefit other species (e.g. kelp forest)

25. is the value of objects, not as ends-in-themselves, but as means of achieving something else