The Nature Of Ecosystems + Human Evolution and Ecology Flashcards
Biosphere
Portion of Earth that contains living organisms
Ecosystems
Organisms + physical and chemical environment
Ecosystems in relation to balance
- Interactions in ecosystems maintain balance, which maintains the balance of the biosphere
- Human activities can alter the interactions between organisms and their environment, tampering with the overall balance
Biomes
Several distinctive major types of earthly ecosystems
Two main divisions are terrestrial and aquatic
Types of Biomes:
- Rain forest
- Savanna
- Grasslands
- Deserts
- Marine
Biotic Components of an Ecosystem
- Living components
- Generally organized as Autotrophs and/or heterotrophs
Autotrophs
- Can automatically make their own food by turning an inorganic substance into an organic one
- Also called produces (because they produce food)
Heterotrophs
- Need a source of organic nutrients
- Are consumers
- Split into Herbivores, omnivores, detrius feeders and carnivores
Herbivores
- Eat plants or alage
Carnivores
- Eat other animals
Omnivores
- Eat both plants and animals
Detritus Feeders
- Organisms that feed on decomposing particles of organic matter
Niche
- The role of an organism in its ecosystem
Diagrams of interactions of all populations in an ecosystem
- Illustrated Energy flow.
- Chemical cycling
Energy Flow
- Can be represented by food web/chain
Trophic Level
- Composed of all of the organisms that feed at a particular link in a food chain.
- Only about 10% of the energy of one trophic level is available to the next trophic level
- The first series of animals are the producers, the second are the primary consumers, the third are the secondary consumers
The Water (hydrologic) Cycle
- Evaporation (called transpiration for plants): The sun causes freshwater to turn to gas and rise
- Condensation: Occurs when the water enters the atmosphere. Water molecules join together when they are cold and reform as a liquid
- Precipitation: The water molecules become too heavy, and fall back to earth
Runnoff
- Water that falls directly into bodies of water
Groundwater
- Water that falls and then sinks into the ground
3 Ways Humans Interfere with the water cycle
- We withdraw water from aquifers
- We clear vegetation from and build man-made structures
- We interfere with the natural processes that purify water and instead add pollutants such as sewage and chemicals to water
Difficulty of Increasing Water Supply
- It takes a long time to build structures that transfer water
The Carbon Cycle
- There is a perpetual exchange pool for carbon dioxide
Reservoirs Hold Carbon
- Living and dead organisms contain organic carbon and serve as one of the resevoirs for the carbon cycle
Fossil Fuels
- Animal remains that have been transformed into coal, oil and natural gass
Climate Change
- Humans have been putting too much carbon into the air through fossil fuels, and now the earth is heating to insane temperatures
Greenhouse effect
- Allows solar radiation to hit the earth, but doesn’t let them escape
Global Warming
- Rise in earth’s tempeture
Nitrogen cycle
- Nitrogen makes up ~78% of the atmosphere in a form that is unusable by plants.
Therefore, nitrogen can be a nutrient that limits the amount of growth in an ecosystem.
- Nitrogen fixation
- Nitrification
- Denitrification
Nitrogen fixation
- Occurs when the nitrogen gas is converted to ammonium, a form that plants can use
Nitrification
def: The production of titrates during the nitrogen cycle
- Nitrogen gas is converted to nitrate in the atmosphere, where high energy is available for nitrogen to react with oxygen. This energy may be supplied by cosmic radiation, meteor trails, or lightning
- Ammonium in the soil from various sources, including decomposition of organisms and animal wastes is converted to nitrate by soil bacteria
- Nitrate-producing bacteria convert ammonium to nitrate. Nitrate-producing bacteria convert nitrite to nitrate
Denitrification
The conversion of nitrate back to nitrogen gas (which then enters the atmosphere)
