CH46: Ecosystems

Phosphorous

essential for organisms to carry out metabolism, found in rocks and sediment

eutrophication

nutrient enrichment of an aquatic ecosystem

ecosystem

an array of organisms and their physical environment, all interacting through a one-way flow of energy and a cycling of nutrients

primary producers

aka autotrophs “self feeders”. capture energy from a nonliving (inorganic) source, typically sunlight. first trophic level

consumers

heterotrophs that obtain energy and carbon by feeding on producers and one another

detritivore

consumer that feeds on small bits of organic material. earthworms and crabs

decomposers

feed on organic wastes. bacteria and fungi

trophic levels

hierarchy of feeding relationships; position of organism on the food chain

troph

nourishment

food chain

sequence of steps that transfers energy from producers to higher trophic levels

food web

consists of cross-connecting food chains

grazing food webs

most primary producers are eaten by primary consumers (grazers/herbivores)

detrital food webs

most energy in producers flows directly to detritivores

primary production

rate at which an ecosystem’s producers capture light and convert it to chemical energy

gross primary production

amount captured by all producers in an ecosystem

net primary production

portion of the energy used for growth and reproduction (rather than maintenance)

biomass pyramid

illustrates the dry weight of all organisms at each trophic level

energy pyramid

illustrates how the amount of usable energy diminishes as it transfers through an ecosystem

biogeochemical cycle

an essential element moves from an environmental reservoir, through the living components, and back to the reservoir

atmospheric cycle

a biogeochemical cycle that includes the atmosphere as a reservoir (water, nitrogen, and carbon)

sedimentary cycle

a biogeochemical cycle that includes sediment (rocks and waters) as a reservoir and not the atmosphere (phosphorous)

water cycle

a biogeochemical cycle that moves water from the ocean to the atmosphere, to land, and back to the oceans

watershed

region in which all precipitation drains into a specific waterway

groundwater

soilwater and water in aquifers

soilwater

water remaining between soil particles

aquifer

natural underground reservoir

earth’s water

97% of earth’s water is seawater, most freshwater is frozen as ice

the carbon cycle

moves among earth’s atmosphere, oceans, rocks, and soils, and into and out of food webs

greenhouse gas

atmospheric gas (CO2) that has the ability to absorb and reradiate heat energy (in all directions) to help keep earth warm and sustain life

global climate change

long term alteration of Earth’s climate

greenhouse effect

the mechanism by which greenhouse gases keep the earth warm

nitrogen cycle

movement of nitrogen among the atmosphere, soil, and water, and into and out of food webs

nitrogen fixation

incorporation of nitrogen from nitrogen gas into ammonia

ammonification

breakdown of nitrogen-containing organic material resulting in the release of ammonia and ammonium ions

nitrification

conversion of ammonium to nitrates

denitrification

an anaerobic reaction carried out mainly by bacteria, converts nitrates to nitrites

nitrous oxide (N2O)

a highly persistent and effective greenhouse gas (can remain in atmosphere for 100+ yrs and has a warming potential 300x greater than CO2). contributes to the destruction of the ozone layer

phosphorous cycle aka sedimentary cycle

movement of phosphorous among Earth’s rocks and water and into and out of food webs . Major reservoir of phosphate is sedimentary rock