gen eco : chap 4

biogeochemical cycles

• the natural pathways by which elements of living matter are circulated through abiotic and biotic components of the earth.

• these cycles are essential for maintaining the balance of life and the environment.

water cycle

• influences weather & climate patterns

• describes the continuous movement of water on, above, below the surface of the earth

evaporation

key processes of water cycle

• water changes from liquid to vapor from surfaces of oceans, lakes, rivers

transpiration

key processes of water cycle

• plants release water vapor into the atmosphere.

condensation

key processes of water cycle

• water vapor cools and forms clouds

precipitation

key processes of water cycle

• water returns to the surface as rain, snow, sleet, or hail

runoff

key processes of water cycle

• water flows over the land into rivers, lakes, and oceans

infiltration and percolation

key processes of water cycle

• water seeps into the ground, replenishing groundwater

carbon cycle

• forming the backbone of organic molecules

• describes the movement of carbon among the atmosphere, biosphere, hydrosphere, and lithosphere

• stores energy for living organisms

photosynthesis

key processes of carbon cycle

• plants absorb carbon dioxide (CO2) from the atmosphere and convert it into organic matter using sunlight

respiration

key processes of carbon cycle

• both plants and animals release CO2 back into the atmosphere through ?

decomposition

key processes of carbon cycle

• decomposers break down dead organisms, releasing carbon into the soil and atmosphere

combustion

key processes of carbon cycle

• burning of fossil fuels and organic matter releases stored carbon as CO2-

sedimentation

key processes of carbon cycle

• carbon is stored long-term in rocks (limestone) and fossil fuels (coal, oil, natural gas)

oxygen cycle

• vital for life

• making up about 21% of earth’s atmosphere

• describes the movement of oxygen within & between its major reservoirs

photosynthesis

key processes of oxygen cycle

• plants release oxygen as a byproduct

respiration

key processes of oxygen cycle

• animals and plants consume oxygen and release CO2

decomposition

key processes of oxygen cycle

• decomposers use oxygen to break down organic matter

ozone formation

key processes of oxygen cycle

• in the stratosphere, UV rays convert O2 to ozone (O3) which protects life by absorbing harmful UV radiation

rusting and weathering

key processes of oxygen cycle

• oxygen is consumed in the oxidation of minerals and rocks

nitrogen cycle

• major component of amino acids, proteins, nucleic acids.

• makes up 78% of the atmosphere

• most organisms cannot use it directly

nitrogen fixation

key processes of nitrogen cycle

• conversion of atmospheric N2 into ammonia (NH3) or related compounds by nitrogen-fixing bacteria, lightning, or industrial processes.

nitrification

key processes of nitrogen cycle

• conversion of ammonia to nitrates (NO2) and then to nitrates (NO3) by nitrifying bacteria

assimilation

key processes of nitrogen cycle

• plants absorb nitrates and incorporate them into organic molecules.

ammonification

key processes of nitrogen cycle

• decomposition of organic nitrogen back to ammonia by decomposers

denitrification

key processes of nitrogen cycle

• conversion of nitrates back to N2 gas by denitrifying bacteria, returning nitrogen to the atmosphere.

phosphorus cycle

• also known as sedimentary cycle

• is a key component of DNA, RNA, ATP, and cell membranes

• unlike carbon & nitrogen, this cycle DOES NOT have a significant gaseous phase

• mainly cycles through rocks, soil, water, and living organisms.

weathering

key processes of phosphorus cycle

• phosphate rocks release phosphates into the soil

absorption

key processes of phosphorus cycle

• plants absorb inorganic phosphate from the soil

consumption

key processes of phosphorus cycle

• animals obtain phosphorus by eating plants or other animals

decomposition

key processes of phosphorus cycle

• organic phosphorus returns to the soil through ?

sedimentation

key processes of phosphorus cycle

• phosphorus can be lost to deep ocean sediments, becoming unavailable for long periods

sulfur cycle

• essential element for proteins and vitamins

• describes the movement of sulfur through the atmosphere, lithosphere, hydrosphere, and biosphere

weathering

key processes of sulfur cycle

• sulfur is released from rocks into the soil and water

absorption

key processes of sulfur cycle

• plants absorb sulfate ions (SO₄²⁻) from the soil

consumption

key processes of sulfur cycle

• animals obtain sulfur by eating plants or other animals

decomposition

key processes of sulfur cycle

• decomposers return sulfur to the soil and atmosphere

volcanic activity

key processes of sulfur cycle

• volcanoes releases sulfur dioxide (SO₂) into the atmosphere

atmospheric deposition

key processes of sulfur cycle

• sulfur returns to the surface via precipitation