Ecosystem Energy Flow, Food Webs, and Biomes: Key Concepts for Biology

Energy Flow

Living things capture and release energy through food chains, food webs and trophic levels.

Primary Producers

Most energy comes originally from the Primary Producers who use the sun and photosynthesis to create sugars used as the basis of the most food webs or Chemosynthesis at deep sea vents.

Food Pyramids

Food pyramids represent the relationship between energy used and lost as it is transferred from one consumer to the next.

Energy Loss

90% of all energy is lost as waste or used by the organism for biologic processes.

Energy Transfer

10% is passed on to the next level as energy they can use.

Decomposers

Decomposers are in all levels of the food pyramid breaking down dead plant and animal matter into simpler usable compounds.

Trophic Levels

The Pyramid shape of the Trophic levels represents population sizes, biomass and energy available in an ecosystem.

Food Chains

Food chains show the relationship between a producer and the chain of consumers that rely on each other in an ecosystem.

Food Webs

Food Webs show all the relationships in an ecosystem between all producers and consumers in an ecosystem showing the flow of energy using arrows pointed towards the consumer from the food source.

Biomagnification

Toxins become more concentrated in higher level consumers of a food web/chain.

Biomes

Biomes of the Earth are large collections of different ecosystems that have similar climates and as a result similar plants and animals.

Abiotic Factors

Climate affects the abiotic factors of a biome and the types of organisms found there.

Dead Zones

Dead zones/Eutrophication is a threat to this environment as is pollution, overfishing, acidification, and invasive species.

Ecosystems

A specific environment and the living things that are supported by it.

Biotic Factors

Any plant, animal, disease or organism that is part of an ecosystem as well as their food sources.

Chemical Cycles

Chemical cycles such as the water, carbon and nitrogen cycles are very important parts of the abiotic factors of an ecosystem.

Carbon Cycle

Carbon cycles through the environment from plants to animals to the air and soil.

Nitrogen Cycle

Nitrogen cycles through the environment from the air as N2 into the ground by nitrogen fixation from bacteria and certain plants.

Niche

The role an organism has in an ecosystem.

Community

Groups of populations that interact in a specific area.

Predator/Prey

The predator eats the prey for survival and which affects the biotic balance of the food chain.

Competition

The struggle between individuals or populations in an ecosystem for limited resources.

Invasive Species

Invasive Species have unfair advantage in an ecosystem allowing them to thrive.

Cooperation

When organisms work together in a way that benefits them all.

Symbiosis

The relationship between two different species who live together in a close relationship.

Mutualism

Both organisms benefit like bees and flowers.

Commensalism

One organism benefits while the other is not affected like moss on a tree.

Parasitism

One organism benefits while the other is harmed like ticks and lice.

Carrying Capacity

The maximum number of organisms that an ecosystem can support.

Population Boom

Unlimited population growth when below the carrying capacity.

Population Bust

Rapid population decline as a result of limiting factors.

Succession

Ecosystems change over time from one type of biological community to another.

Primary Succession

Forms from bare earth without organic matter or decomposers.

Secondary Succession

Occurs when an ecosystem returns to its natural state after a disturbance.

Pioneer species

The living things that first move into a barren area after something like a lava flow.

Organism

A single individual animal, plant or other living thing.

Population

A group of organisms of the same species living in the same area.

Ecosystem

A community of organisms and the non-living factors that influence them.

Biome

Ecosystems adapted to similar climate conditions into global ecological regions.

Biosphere

The part of earth that contains all ecosystems.

Trophic level

The position an organism occupies in a food chain.

Heterotrophs

Organisms that obtain organic carbon by eating other heterotrophs.

Primary consumers

Herbivores that consume primary producers.

Secondary consumers

Carnivores that eat herbivores.

Tertiary consumers

Carnivores that eat other carnivores.

Detritivore

An organism that feeds on detritus, dead and decomposing matter.

Decomposer

An organism that breaks down organic matter, recycling nutrients back into the environment.

Photoautotroph

An organism that makes its own food using light.

Nitrogen fixation

The process of converting nitrogen from the atmosphere into a usable form like nitrates and nitrites.

Food chain

Describes who eats whom in the wild, showing energy and nutrient pathways.

Food web

All of the interconnected and overlapping food chains in an ecosystem.

Limiting resource

A resource that becomes limiting when the population density reaches a certain level.

Ecological succession

How ecosystems change over time.

Primary ecological succession

The ecological change that takes place in an empty and barren environment with no soil.

Climax community

A stable group of plants and animals that is the end result of the succession process.