APES Chapter 3

ecosystem

location on Earth distinguished by its particular mix of interacting biotic and abiotic components (such as organisms, soil, water, temperature, salinity, sunlight)

producers/autotrophs

organisms able to use the Sun's energy to create usable forms of energy through the process of photosynthesis

photosynthesis

the process by which producers/autotrophs use solar energy to convert carbon dioxide and water into oxygen and glucose (potential energy usable by other organisms)

cellular respiration

process which unlocks the chemical energy stored in the cells of organisms by converting glucose and oxygen into water, carbon dioxide, and ENERGY

consumers/heterotrophs

organisms incapable of photosynthesis and must obtain energy by consuming other organisms

primary consumers

organisms that eat producers; herbivores

secondary consumers

organisms that eat primary consumers; carnivores

tertiary consumers

organisms that eat secondary consumers; carnivores

trophic levels

successive levels of organisms consuming one another

food chain

sequence of trophic levels from producers to tertiary consumers

food web

model of trophic relationships which accounts for organisms which consume on multiple trophic levels and includes scavengers, detrivores, and decomposers

scavengers

carnivores who consume dead organisms

detrivores

organisms who break down dead biomass and waste productes into smaller particles

decomposers

organisms who complete the breakdown process of dead biomass and recycle the nutrients back into the ecosystem

gross primary productivity

the total amount of photosythesis/solar energy input in an ecosystem in a given amount of time

net primary productivity

the amount of solar energy input in an ecosystem in a given amount of time minus the energy lost when producers respire

biomass

total mass of all living matter in a specific area

standing crop

the amount of biomass present in an ecosystem at a given time

ecological efficiency

the proportion of consumed energy that can pass through trophic levels in an ecosystem

trophic pyramid

represents the distribution of energy and biomass among trophic levels in an ecosystem

biosphere

region of our planet that can sustain life; energy flows through and matter cycles within

biogeochemical processes

movements of matter within/between ecosystems which involve biological, geological, and chemical processes

hydrologic cycle

movement of water through the biosphere

transpiration

the process by which leaves release water into the atmosphere, a byproduct of photosynthesis

evapotranspiration

the combined amount of evaporation and transpiration in an ecosystem; a scientific measure of the water flowing through an ecosystem

runoff

water which moves across land surface until it reaches streams, rivers, and eventually the ocean

carbon cycle

photosynthesis, respiration, exchange, burial/sedimentation, extraction, combustion

macronutrients

six key elements that organisms need in relatively large amounts: nitrogen, phosphorous, potassium, calcuium, magnesium, and sulfur

limiting nutrient

nutrient which when lacking constrains the growth of organisms and when abundant alters distribution/population size of species

nitrogen fixation

process by which N2 is converted into usable nitrogen in the forms of ammonium (biotic) or nitrate (abiotic)

leaching

process by which elements/nutrients are transported through water in the soil

disturbance

event caused by biological, physical, or chemical changes which leads to change in an ecosystem's population size or community composition

watershed

the land in a given location that drains into a particular body of water

resistance

measure of how much a disturbance effects the flow of energy and matter in an ecosystem

resilience

rate at which an ecosystem can recover and return to its original state after a disturbance

restoration ecology

scientific discipline which works to restore damaged ecosystems

intermediate disturbance hypothesis

states that ecosystems with intermediate levels of disturbance are more diverse than those with high or low levels of disturbance

instrumental value

worth of a species in their ability to be used to accomplish a goal/benefit humans

intrinsic value

worth of a species independent of any human benefits

provisions

goods/environmental services that humans can use directly

regulating services

ability of natural ecosystems to maintain environmental conditions such as global climate and nutrient/hydrologic cycles

support systems

services ecosystems provide that enable other systems to continue but would be costly for humans to generate

resilience

factors such as species diversity ensure that an ecosystem will continue to exist in its current state, which means it can continue to provide services that benefit humans

cultural services

instrumental value of intellectual gain and aesthetic satisfaction that ecosystems provide