community
assemblage of all the populations of organisms living close enough together for potential interaction
interspecific competition
relationships with individuals of other species in the community that greatly affect population structure and dynamics
mutalism
both populations benefit from one another
predation (predator/prey)
interaction in which one species (the predator) kills and eats another (the prey)
herbivory
consumption of plant parts of algae by an animal
parasite
an organism that lives off another organism of another species, one receives an advantage over the other
pathogen
an organism causing a disease to the host benefiting the disease and not the host
ecological niche
the sum of its use of the biotic and abiotic resources in its environment
camouflage
provide protection against predators, common in other animals
coevolution
a series of reciprocal evolutionary adaptations in two species, a change in one species acts as a new selective force in another species
trophic structure
a pattern of feeding relationships consisting of several different levels
food chain
the sequence of food transfer up the trophic levels
producers
the trophic level that supports all others consisting of autotrophs
primary consumers
herbivores which eat plants, algae, or phytoplankton in this trophic level
secondary consumers
include many small mammals, such as a mouse, and a great variety of birds, frogs, and spiders, as well as lions and other large carnivores that eat grazers in this trophic level
tertiary consumers
a high trophic level such as snakes that eat mice or other secondary consumers
quaternary consumers
include hawks in terrestrial ecosystems and killer whales in the marine environment in this trophic level
detritivores
scavengers that consume the detritus (dead material produced at all the trophic levels)
decomposers
derive their energy from the detritus (dead material produced at all the trophic levels), examples are prokaryotes and fungi, which secrete enzymes that digest molecules in organic material and convert them into inorganic forms
food web
a network of interconnecting food chains
species diversity
a community is defined by two components: species richness, or the number of different species in a community, and relative abundance, the proportional representation of a species in a community
keystone species
species whose impact on its community is much larger than its biomass or abundance indicate
ecological succession
the disturbed area may be colonized by a variety of species, which are gradually replaced by a succession of other species in this process
secondary succession
occurs where a disturbance has destroyed an existing community but left the soil intact
primary succession
when ecological succession begins in virtually lifeless area with no soil
invasive species
spreading far beyond the original point of introduction causing environmental or economic damage by colonizing and dominating wherever they find a suitable habitat
biological control
the intentional release of a natural enemy to attack a pest population
ecosystem
consists of all the organisms in a community as well as the abiotic environment with which the organisms interact
energy flow
the passage of energy through the components of the ecosystem
chemical cycling
the transfer of materials within the ecosystem
biomass
the amount or mass of living organic material in an ecosystem
primary production
the amount of solar energy converted to chemical energy (in organic compounds) by an ecosystem's producers for a given area and during a given time
pyramid of production
illustrates the cumulative loss of energy with each transfer in a food chain
biogeochemical cycles
because chemical cycles in an ecosystem include both biotic and abiotic (geological and atmospheric) components they are called ..
abiotic reservoir
where a chemical accumulates or is stockpiled outside of living organisms
carbon cycle
Photosynthesis removes CO2 from the atmosphere and incorporates it into organic molecules, which are passed along the food chain by consumers, cellular respiration returns CO2 into the atmosphere, decomposers break down the carbon compounds in detritus; t
phosphorus cycle
The weathering (breakdown) of rock gradually adds inorganic phosphate to the soil, plants assimilate the dissolved phosphate ions in the soil and build them into organic compounds, consumers obtain phosphorus in organic form from plants, phosphates are re
nitrogen cycle
Some bacteria live symbiotically in the roots of certain species of plants, supplying their hosts with a direct source of usable nitrogen. Free-living nitrogen-fixing bacteria and cyanobacteria in soil or water convert N2 from air pockets in the soil to a