ecosystem
A particular location on Earth distinguished by its particular mix of interacting biotic and abiotic components.
producers
Plants, algae, and other organisms that use the Sun's energy to produce usable forms of energy.
autotrophs
Organisms that make their own food.
photosynthesis
Process by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates such as sugars and starches
cellular respiration
Process that unlocks the chemical energy stored in the cells of organisms.
consumers
Organisms that are incapable of photosynthesis and must obtain their energy by consuming other organisms.
heterotrophs
Organisms that are incapable of photosynthesis and must obtain their energy by consuming other organisms.
primary consumers
Heterotrophs that consume producers.
secondary consumers
Carnivores that eat primary consumers.
tertiary consumers
Carnivores that eat secondary consumers.
food chain
The sequence of consumption from producers through tertiary consumers.
food web
This takes into account the complexity of nature and they illustrate one of the most important concepts: that all species in an ecosystem are connected to one another.
scavengers
Carnivores that consume dead animals.
detritivores
Organisms that specialize in breaking down dead tissues and waste products into smaller particles.
decomposers
The fungi and bacteria that complete the breakdown process by recycling the nutrients from dead tissues and wastes back into the environment.
gross primary productivity
Environmental scientists look at the total amount of solar energy that the producers in an ecosystem capture via photosynthesis over a given amount of time.
net primary productivity
The energy captured minus the energy respired by producers.
biomass
The total mass of all living matter in a specific area.
standing crop
Amount of biomass present in an ecosystem at a particular time.
ecological efficiency
The proportion of consumed energy that can be passed from one trophic level to another.
trophic pyramid
Representation of the distribution of biomass among trophic levels.
biosphere
The region of our planet where life resides.
bio-geochemical cycles
Movements of matter within and between ecosystems involve biological, geological, and chemical processes.
hydrolic cycle
The movement of water through the biosphere.
transpiration
When plants release water from their leaves into the atmosphere.
evapotranspiration
The combined amount of evaporation and transpiration.
runoff
Water moving across the land surface and into streams and rivers, eventually reaching the ocean.
macronutrients
Six key elements that organisms need in relatively large amounts: nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur.
limiting nutrient
A nutrient required for the growth of an organism but available in a lower quantity than other nutrients.
nitrogen fixation
A few organisms that convert nitrogen gas directly into ammonia.
leaching
Nitrate is readily transported through the soil with water.
disturbance
Event caused by physical, chemical, or biological agents that results in changes in population size or community composition.
watershed
All of the land in a given landscape that drains into a particular stream, river, lake, or wetland.
resistance
A measure of how much a disturbance can affect the flows of energy and matter.
resilience
The rate at which an ecosystem returns to its original state after a disturbance.
restoration ecology
Growing interest in restoring damaged ecosystem.
intermediate disturbance hypothesis
Ecosystems experiencing intermediate levels of disturbance are more diverse than those than those with high or low disturbance levels.
instrumental value
A species has worth as an instrument or tool that can be used to accomplish a goal.
intrinsic value
A species has worth independent of any benefit it may provide to humans.
provisions
Goods that humans can use directly.