Bio Chp 35

community of organisms + the physical enviornment with which they interact

• Biotic = living
• abiotic = nonliving

• Resources: Nutrients
• Condidtions: temperature

Temperature and precipitation are the twop two affectors of ecosystems

the movement of water and nutrients between the biotic and abiotic world

"nature's form of recycling"

• CO₂ is released during respiration
• CO₂ is released during composition

• 1. photosynthesis
• 2. respiration
• 3. dead organisms
• 4. fossil fuels
• 5. burning of fossil fuels

• makes up portion of atmosphere
• It feeds everyone
• impacts global temperature

• 1. nitrogen fixation
• 2. assimilation into plants
• 3. decomposition by bacteria and fungi
• 4. nitrifying bacteria
• 5. denitrifying bacteria

-synthetic fertilizers: industrial process for nitrogen fixation that converts N gas into formas plants can use

-Humans are n-fixers: they are #1 n-fixers in the world

• -nutrient pollution: runoff from agricultural lands.
• excess nitrogen results in "dead zones" where life is unable to grow

• precipitation
• runoff
• groundwater
• lakes
• evaporation

evaporation, precipitation, H₂O movement

Glaciers and polar ice

• 2.5% of all water on Earth
• 25% of that freshwater is groundwater

an ecosystem that is wet for at least part of the year. It also can be under a permanent cover of water


examples: swamps or marshes

• very productive and imporant habitats for migratory birds
• filtering systemof the world

"kidney's of the earth"

• inefficient use of water (bad agricultural practices)
• humans are using a larger proportion of water (more people)

• The law of conservation: energy never gained or lost, only transformed
• The law of entropy: energy always flows from more-ordered to less-ordered state

heat

different feeding levels.

• There are two types: producers & consumers.
• Producers: plants and other photosynthesizers
• Consumers: all other organisms

• -not all members consumed
• -some energy is lost throughout the process
• -for each jump in trophic level, the amount of available energy drops 90%

consumes dead or "cast off" organic matter. Detritivores break down inorganic componenets that can then be recycled.

Measures energy as it is used by and transferred among different members of an ecosystem

• very little solar energy assimilated by plants is avaible to the higher trophic levels
• not enough energy to have a big population

layer of gases surrounding the Earth.

• Composed of:
• -troposphere
• -stratosphere

lowest atmospheric layer, contains most of the gases

• 99% nitrogen and oxygen
• small amount of CO₂

other trace gasses: argon, methane, etc.

higher up, contains ozone layer (O₃)

a layer of gasses that screens out 99% of the sun's UV radiation.

by the use of human-made compounds

• Chlorofluorocarbons (freon) : found in refigerators
• Aerosols

CFC's converted the ozone layer into O₂

since the earth is tilted at 23.5 degrees there are different types of climates found throughout the world.

• Changes in:
• temperature
• precipitation

Patches of moving air that are greatly affected by the differences of warming.

• rains where it rises
• dry where it descends

average weather condition in a given area.

(helps dicate what the biotic world looks like)

at least 90%

large terrestrial regions of the earth that have similar climates and hence similar vegetative formations.

• Tundra
• Taiga
• Temperate deciduous forest
• Temperate grassland
• Desert
• Tropical rain forest

where gasses such as CO₂ and methane trap heat that comes to the Earth from the sun. Thus warming the Earth much the same as a greenhouse

• Burning of fossil fuels
• Deforestation

an increase by 1.8 degrees C to 4.0 degrees C

• Glacial melt
• sea level rise
• more "extreme" conditions
• habitat loss - species loss
• ocean acidification