Poop Flashcards
There were only a few million people on earth until what two things happened about 8,000 years ago?
Agriculture and domestication
What is an area where trees cover called?
Forest
Tropical rain forests contain 1/2 of all what?
Species on earth
Where is the largest tropical forest located?
Amazon rain forest
Where is the largest overall forest located?
Europe/Asia (coniferous)
What type of forest has trees that “die of old age” and are relatively undisturbed by humans?
Old-growth forest
Do old growth forests contain a high or low level of diversity?
High
What product plays a part in more activities of the modern economy than any other commodity?
Wood
What kind of countries produce less than half of all industrial wood, but account for 80% of consumption?
Developed countries
Industrial logging in N. America and Europe occur in what type of forest?
Managed forest
From what area does most unsustainable logging occur?
Tropical forests
What is the growth and harvest of trees as a commercial product called?
Forestry
What is the removal of trees without replacement?
Deforestation
About how many acres per second is removed from the rainforest?
1 acre
What are the causes (3) for tropical deforestation?
Logging, Nutrient poor soils, & changing rainfall patterns
What percent of old-growth forest remains intact in the United States?
> 10%
What two types of birds are dependent on old-growth forests?
Northern spotted owl and marbled murrelet
What is clear cutting?
Harvesting of all trees in an area
What are the disadvantages to clear cutting?
Loss of habitat and soil erosion
What is clear cutting with reserves?
Patches of trees left standing in an otherwise clear cut area
What kind of harvesting method leaves “seed trees” left standing for several years to be later harvested?
Shelterwood harvesting
What kind of harvesting method cuts trees in successive strips at different times?
Strip cutting
What kind of harvesting method cuts trees in scattered groups?
Selective harvesting
What are the current issues with logging in the US?
Subsidized logging doesn’t cover costs, and emphasis on road building
What are the negative effects to overgrazing?
Erosion, loss of native forage species, and desertification
What was the first national park in the US?
Yellowstone
What phenomena caused the population boom 8,000 years ago?
Agriculture and domestication
What is the rule of 70?
70 years / % growth = doubling time in years
What did Malthus propose?
Excess population growth causes poverty and war
What did Marx propose?
Exploitation oppression causes poverty, which then leads to excess population growth and war
What are the vital statistics about people called?
Demographics
What three components make up demographics?
Birth rates, death rates, and distribution of population
What is the number of births/deaths per thousand persons?
Crude birthrate/deathrate
What is the number of births per average woman over her lifetime?
Total fertility rate
What is it called when the birth rate = the death rate?
Zero population growth (ZPG)
What is the primary cause of population growth in recent history?
Declining mortality rate
What is the oldest age attainable by a member of a species?
Lifespan