Chapter 29: Energy Flow and Nutrient Cycling in Ecosystems

nutrients

atoms and molecules that organisms obtain from environment

producers (autotrophs)

organisms that can produce their own food

consumers (heterotrophs)

organisms that cannot produce their own food

net primary production

the amount of energy that photosynthetic organisms in a given area store in their bodies over a given period of time; measured in biomass

plants

in land based ecosystems, _____ are the dominant producers

phytoplankton

in most aquatic food chains, the dominant producers are ___________

zooplankton

consists of protists and small shrimp like crustaceans

detritivores

an army of small nematode worms, earthworms, millipedes, and dung beetles

omnivores

everything eaters; act as primary, secondary, and tertiary consumers

energy pyramid

illustrates the energy relationships between trophic levels

10% law

the insufficient energy transfer between trophic levels

biogeochemical cycles

earth’s fixed supply of nutrients moves through ecosystems via _________ ______

1. water

2. carbon

3. nitrogen

4. phosphorous

organisms require a wide variety of nutrients including:
1.
2.
3.
4.

water cycle

pathway by which water travels from major reservoirs to reservoirs in freshwater lakes

carbon cycle

carbon moves from reservoirs in the atmosphere and oceans, through producers, consumers, detritivores, and decomposers, and then back to the reservoir

rocks

biggest reservoir of carbon is in ______

fossil fuels

additional long term reservoirs for carbon but contain way less carbon than rocks

atmosphere

major reservoir of nitrogen

nitrogen cycle

nitrogen moves from its primary reservoir in the atmosphere to much smaller reservoir of ammonia and nitrate in soil and water

nitrogen fixation

certain bacteria in soil and water convert N₂ into ammonia and other

rock

major reservoir of phosphorus

P cycle

when rocks are exposed, phosphorous moves to smaller reservoirs in soil and water, to living things, and then back to its reservoirs

climate change

the overall impact of increased greenhouse gases