Chapter 16: Marine Communities Flashcards
what is a community?
group composed of many populations of organisms that interact at a particular location
what is a population?
a group of organisms of the same species occupying a specific area
where is the largest marine community located?
within the uniform mass of permanently dark water between the sunlit surface and the deep bottom
what are communities dependent on?
the availability of energy
what is a habitat?
an organism’s “address” within its community, its physical location
what is an organism’s niche?
an organism’s “occupation” within its habitat, its relationship to food and enemies, an expression of what the organism is doing
what is ecology?
the study of the balance of physical and biological factors and of the relationships of organisms and interactions within communities
what is environmental resistance?
the sum of the effects of these limiting factors in the environment
what is the carrying capacity?
the population size of each species that a community can support indefinitely under a stable set of environmental conditions
what is population density?
the number of individuals per unit area (or volume)
what does random distribution mean?
implies that the position of one organism in a community in no way influences the position of other organisms in the same community
what is the most common pattern of population distribution?
clumped distribution
what is clumped distribution?
occurs when conditions for growth are optimal in small areas because of physical protection, nutrient concentration, initial dispersal, or social interaction
what is uniform distribution?
occurs when there is equal space between individuals
what is the rarest distribution pattern of them all?
uniform distribution
what is a climax community?
a stable, long-established community, self-perpetuating aggregation of species. tends not to change unless disrupted by severe external forces
what is succession?
the orderly changes of a community’s species composition from temporary inhabitants to long-term inhabitants
what is the intertidal zone?
the band between the highest high tide and lowest low tide
what is one of the Earth’s most densely populated areas?
the intertidal zone
what is wave shock?
the powerful force of crashing waves
what is dessication?
drying out by exposure to air and sunlight
what is an estuary?
a broad, shallow, river mouth where freshwater and saltwater mix
do estuaries have more or less wave shock?
less
what is brackish water?
mixed saltwater and freshwater
what are macroplankton?
plankton that are larger than about 1 cm
what are holoplankton?
zooplankton that spend their whole lives in the plankton community
what are meroplankton?
plankton who are temporary visitors as the juvenile stages of crabs, barnacles, etc.
what is one of the ocean’s most important zooplankters?
krill
where is about 83% of the ocean’s total biomass concentrated?
its uppermost 200 meters
what is the deep scattering layer (DSL)?
a relatively dense aggregate of fishes, squid, and other animals that usually migrate up and down in synchrony with daylight
what is symbiosis?
the co-occurrence of two species in which the life of one is closely interwoven with the life of the other
what occurs in mutualism?
both the symbiont and the host benefit from the relationship
what occurs in commensalism?
the symbiont benefits from the association while its host neither benefits nor is harmed
what occurs in parasitism?
the parasite lives in or on the host for at least part of its life cycle and obtains food at the host’s expense
what is the most common type of symbiotic relationship?
parasitism
what is a species-specific relationship?
an exclusive relationship between two species
