Energy Flows and Matter Cycles
EK 4.A.6 Interactions among living systems & with their environment
result in the movement of matter & energy
Energy Flows through Trophic LevelsPrimary Producers –
autotrophs capable of converting solar energy into chemical energy (plants, photosynthetic protists, cyanobacteria and chemosynthetic bacteria
Energy Flows through Trophic Levels
Primary Consumers – herbivores that eat primary producers
Secondary consumers – primary carnivores that eat primary consumers
Tertiary consumers – secondary carnivores eat the secondary consumers
Energy Flower through Trophic LevelsDetritivores – consumers
that obtain their energy by consuming dead plants and animals (detritus); the smallest are called decomposers and include fungi and bacteria; others include nematodes, earthworms insects and scavengers such as crabs, vultures, and jackals
Energy Flows through Trophic LevelsEcological Pyramids – used
to show the relationship between the tropic levels; Horizontal bars or tiers are used to represent the relative size of the tropic levels, each represented in terms of energy (productivity), biomass or numbers of organisms; tiers are stacked upon one another in the order in which energy is transferred
Energy Flow through Trophic LevelsEcological Efficiency –
describes the proportion of energy represented at one trophic level that is transferred to the next level; only about 10% of the productivity (energy) of one trophic levels is transferred to the next level; 90% of the energy is consumed by the individual metabolic activities of the organism
Energy Flows through Trophic LevelsFood Chain – linear
flow chart of who eats whom; shows energy flow
Food Web – expanded, more complete version of food chain; Arrows connect all organisms that are eaten to the animals that eat them in the direction of the energy flow
Matter is RecycledBiogeochemical
Cycles – describe the flow of essential elements from the environment to living things and back to the environment
Why do we need these elements to be recycled? What purpose do they serve?
Matter is RecycleHydrological cycle
Reservoirs – oceans, air (as water vapor), groundwater, glaciers, (evaporation, wind and percipitation move water from oceans to lands
Assimilation – plants absorb water from the soil animals drink water or eat other organisms (which are mostly water)
Release – plants transpire; animals and plants decompose
Matter is RecycleCarbon Cycle
Reservoirs – atmosphere (as CO2), fossil fuels (coal and oil), peat, durable organic material (i.e. cellulose)
Assimilation – plants use CO2 in photosynthesis; animals consume plants or other animals
Release – plants and animals release CO2 through respiration and decomposition; CO2 is released when organic material is burned
Matter is RecycledNitrogen Cycle
Reservoirs – atmosphere (N2); soil (NH4 ammonium, NH3 ammonia, NO2 nitrite, or NO3 nitrate)
Assimilation – plants absorb nitrogen either as nitrate or ammonium; animals obtain nitrogen by eating plants or other animals
Matter is RecycledNitrogen
AssimilationNitrogen Fixation –
Nitrogen gas and ammonium are fixed by nitrogen-fixing prokaryotes (in soil or root nodules); nitrogen gas is converted to ammonia by lightening and UV radiation
Matter is RecycledNitrogen
Assimilation Nitrification –
ammonium converted to nitrite and nitrite converted to nitrate by various nitrifying bacteria; ammonium or nitrate converted to organic compounds by plant metabolism
Matter is RecycleNitrogen Cycle
Release – denitrifying bacteria convert nitrate back to nitrogen gas (denitrification); detrivorous bacteria convert organic compounds back to ammonium (ammonification); animals excrete ammonium or ammonia, urea or uric acid
Matter is RecycledPhosphorus Cycle
Reservoirs – rocks and ocean sediments
Assimilation – plants absorb inorganic phosphate from soils; animals obtain organic phosphorous when then eat plants or other animals
Release – plants and animals release phosphorous when they decompose; animals excrete phosphorous in their waste products