Biome

Gross Primary Productivity (GPP)

Net Primary Productivity (NPP)

Gross Secondary Productivity (GSP)

Net Secondary Productivity (GSP)

Autotrophs

Heterotrophs

Species

Population

Habitat

Ecological niche

Community

Ecosystem

Biosphere

Biotic factors

Abiotic factors

Food chain

Food web

Trophic level

Producer

Consumers

Decomposers

Detritivores

Bioaccumulation

Biomagnification

Intraspecific competition

Interspecific competition

Predation

Herbivory

Parasitism

Mutualism