Summary
Ecosystems exist on land, at sea, in the air, and underground. Different ways of modeling ecosystems are necessary to understand how environmental disturbances will affect ecosystem structure and dynamics. Conceptual models are useful to show the general relationships between organisms and the flow of materials or energy between them. Analytical models are used to describe linear food chains, and simulation models work best with holistic food webs.
Glossary
analytical model
ecosystem model that is created with mathematical formulas to predict the effects of environmental disturbances on ecosystem structure and dynamics
apex consumer
organism at the top of the food chain
conceptual model
(also, compartment models) ecosystem model that consists of flow charts that show the interactions of different compartments of the living and non-living components of the ecosystem
detrital food web
type of food web in which the primary consumers consist of decomposers; these are often associated with grazing food webs within the same ecosystem
ecosystem
community of living organisms and their interactions with their abiotic environment
ecosystem dynamics
study of the changes in ecosystem structure caused by changes in the environment or internal forces
equilibrium
steady state of an ecosystem where all organisms are in balance with their environment and each other
food chain
linear representation of a chain of primary producers, primary consumers, and higher-level consumers used to describe ecosystem structure and dynamics
food web
graphic representation of a holistic, non-linear web of primary producers, primary consumers, and higher-level consumers used to describe ecosystem structure and dynamics
grazing food web
type of food web in which the primary producers are either plants on land or phytoplankton in the water; often associated with a detrital food web within the same ecosystem
holistic ecosystem model
study that attempts to quantify the composition, interactions, and dynamics of entire ecosystems; often limited by economic and logistical difficulties, depending on the ecosystem
mesocosm
portion of a natural ecosystem to be used for experiments
microcosm
re-creation of natural ecosystems entirely in a laboratory environment to be used for experiments
primary consumer
trophic level that obtains its energy from the primary producers of an ecosystem
primary producer
trophic level that obtains its energy from sunlight, inorganic chemicals, or dead and/or decaying organic material
resilience (ecological)
speed at which an ecosystem recovers equilibrium after being disturbed
resistance (ecological)
ability of an ecosystem to remain at equilibrium in spite of disturbances
secondary consumer
usually a carnivore that eat primary consumers
simulation model
ecosystem model that is created with computer programs to holistically model ecosystems and to predict the effects of environmental disturbances on ecosystem structure and dynamics
tertiary consumer
carnivore that eat other carnivores
trophic level
position of a species or group of species in a food chain or a food web