Biology Chapter 46: Ecosystems

Ecosystem

All the living organisms in an area as well as the abiotic factors with which they interact; can be ome or more communities and the physical environment around them

Steady state

All organisms are in balance with the environment and each other

Resistance

The level of ability of an ecosystem to remain in equilibrium despite disturbance; ability to avoid change

Resilience

The speed at which an ecosystem recovers after being disturbed

Food chain

Linear sequence of organisms through which nutrients and energy pass

Primary producers

Photoautotrophs

Primary consumers

herbivores

Secondary consumers

Carnivores that eat the herbivores

Tertiary consumers

Carnivores that eat other carnivores

Detritivores

Heteroautotrophs that eat dead matter

Apex predator

Top of the food chain

Food web

All the food chains in an ecosystem; all the possible paths that energy and nutrients make as they move through the ecosystem

Trophic levels

Categories for organisms in food webs

First law of thermodynamics

Energy cannot be created or destroyed but only transferred or transformed

Law of conservation of mass

Mass cannot be created or destroyed

Energetics

Control by energy of the food web length

Ecosystem energy budget

Total amount of photosynthetic production of the ecosystem

Gross primary production (GPP)

Amount of light converted to chemical energy

Net primary production definition

The energy available to primary consumers

Net primary production equation

NPP = GPP - energy used by primary producers

Equation for efficiency of digestion

New biomass/energy stored in the food = efficiency of digestion

Tropic efficiency

Percentage of production transferred from one trophic level to the next; averages at 10%