because atmospheric N cannot be used directly by plants it must first be converted into ammonia by bacteria
Ammoniafication:
decomposers covert organic waste into ammonia
Nitrification:
ammonia is converted to nitrate ions (NO-3)
Assimilation:
inorganic N is converted into organic molecules such as DNA/aminoacids & proteins
Denitrification:
bacteria convert ammonia back into N
Phosphorus
does not circulate as easily as N because: it does not exist as a gas, but isreleased by weathering of phosphate rocks
Sustainability:
the ability to meet humanities current needs without compromising theability of future generations to meet their needs
Photosynthesis:
plants convert atmospheric C (CO) into complex carbohydrates(glucose C6H12O6)
Aerobic respiration:
oxygen consuming producers, consumers & decomposers breakdown complex organic compounds & convert C back into CO2
Largest reservoirs of Carbon:
carbonate rocks first, oceans second
Biome:
large distinct terrestrial region having similar climate, soil, plants & animals
Carrying capacity:
the number of individuals that can be sustained in an area
R Strategist v K Strategist
R strategist: reproduce early, many small unprotected offspring K strategist:reproduce late, few, cared for offspring
Positive feedback:
when a change in some condition triggers a response that intensifies the changing condition (EX: warmer Earth – snow melts – less sunlight isreflected & more is absorbed, therefore warmer earth)
Malthus:
said human population cannot continue to increase.
Consequences will be war, famine & disease
Doubling time:
rule of 70 70 divided by the percent growth rate
Replacement level fertility:
the number of children a couple must have to replacethemselves (2.1 developed, 2.7 developing)
World Population is:
almost 6 1/2 billion US Population: 299 million
Preindustrial stage:
birth & death rates high, population grows slowly, infantmortality high
Transitional stage:
death rate lower, better health care, population grows fast
Industrial stage:
decline in birth rate, population growth slows
Postindustrial stage:
low birth & death rates
Age structure diagrams:
(broad base, rapid growth)(narrow base, negativegrowth)(uniform shape, zero growth)
1st & 2nd most populated countries:
China & India
Most important thing affecting population growth:
low status of women
Ways to decrease birth rate:
family planning, contraception, economic rewards &penalties
Negative feedback:
when a changing in some condition triggers a response that Counteracts the changed condition (EX: warmer earth – more ocean evaporation – more Stratus clouds – less sunlight reaches the ground – therefore cooler Earth
Greenhouse gases:
(Examples: H2O, CO, O3, methane (CH4), CFC’s) (EFFECT:they trap outgoing infrared (heat) energy causing earth to warm