chapter 20 Flashcards
what is a community
consists of two or more populations of different species, living in the same geographic area and interacting with one another
what is mutualism, what are some examples
an interaction between two species in which both species benefit
[shrimp shares its burrow with golby for protection; insects receive food from plants while spreading pollen from plant to plant; bacteria digest the cellulose in termites while living in digestive track] plus//plus
what is predation, what are some examples
an interaction between species in which one species eploits another living species for food [hare and lynx] plus//minus
what are keystone predators
not necessarily abundant in a community, but they exert as strong effect on the community structure [sea star]
what are some prey defenses
camouflage, hiding, running away, gathering in large numbers, weaponry, chemical defenses, warning coloration
what is parasitism, what are some examples plus//minus
an interaction between species in which the parasite benefits at the expense of the host by living either within or on the host
[fungus & American elm] if too successful, leads to extinction
[rabbits & viruses in Australia] coevolution of both parasite and host
what is biological control
using one organism to control the numbers of another
what is competition, what is competitive exclusion – what are some examples minus/minus*
an interaction between populations living in a common environment and sharing a limited resource minus//minus
distinguish between habitat and niche
—>habitat – place where an organism lives
—>niche – the role than an organism plays in the place where it lives
distinguish between a fundamental niche and a realized niche
—>fundamental niche – the physical limits of tolerance of the organism
—>realized niche – that portion of the fundamental niche which is actually utilized, determined by the physical factors and competition
what is resource partitioning
closely related species avoiding excessive competition while sharing the same resource in different ways, areas or times
distinguish between interspecific competition and intraspecific competition
—>intraspecific – within a single species
—>interspecific – between different species
what is territoriality
individual or groups that claim a geographic area by defending it against intruders intraspecific competition
what is ecological succession
the slow process whereby one community of plants and animals replaces another —- typically very slow process
distinguish between primary succession and secondary succession
—>primary succession – establishes new communities in new previously unoccupied surfaces [bare rock, sand, bare soil]
—>secondary succession – the recovery of a once-vegetated area as it grows again towards climax [forest fires, volcanic eruptions]
what are the stages of invasion in ecological succession
migration —>establishment —>aggregation —>competition
what is a climax community
the terminal stage to which a plant community develops under a stable climate
what is the climax community of this region
oak, hickory, beech, maple
what is an ecosystem
community of plants and animals plus their non-living environment through which energy flows and minerals cycle
what are the abiotic components of an ecosystem
water, oxygen, carbon dioxide, minerals, continuous supply of energy
what are the biotic components of an ecosystem
producers, consumers, primary consumers, secondary consumers, tertiary consumers, and decomposers(detritivores)
what is a food chain,
series of organisms, each of which is eaten by the next
what is a food web
interconnected with one another in an overall pattern
what is a trophic level
the feeding level in a food chain to which an organism belongs
why are energy conversions in an ecosystem never 100% efficient
the amount of energy at each level that is available to be passed on is reduced because large amounts of energy loss [wastes; heat energy] therefore, there is not enough left to be passed on
what limits the number of trophic levels in an ecosystem
limited amount of energy, not all food in one trophic is eaten and not all eaten food is useful [nutrients]
[on average, animals convert only 10% of energy they consume into new animal growth]
what is a pyramid of energy
the flow of energy through an ecosystem
what is productivity
the amount of organic matter produced by the members of a given trophic level during a given period pf time
which ecosystem contributes the most to the Earth’s net primary productivity
open oceans
what are biogeochemical cycles
the movement of nutrient elements through an ecosystem by physical and biological processes
what are the two general types of biogeochemical cycles
–>sedimentary –major reservoir is some sedimentary material such as soil, rocks or water
–>atmospheric(gaseous) – major reservoir is the atmosphere
describe three examples of biogeochemical cycles
carbon cycle, nitrogen cycle [Hubbard Experimental Forest, forest cutting experiment] water cycle, & phosphorus cycle
why are decomposers important in the biogeochemical cycles
they are responsible for the breakdown and return of nutrients back into the environment
what do scientists think is the main cause of global warming
(humans) pollution of nitrogen oxides in the atmosphere
describe the water cycle, what are the three phases of the water cycle
evaporation, precipitation, runoff
what is acid rain
sulfur and nitrogen mixed compounds (sulfuric acid) with water in the atmosphere
what is pollution
wastes that are not destroyed as fast as they are produced or cannot be bio-degraded by the decomposers
distinguish between primary productivity and secondary productivity
primary productivity – rate at which energy is stored in organic matter by photosynthesis in producers
*gross primary productivity minus respiration = net primary productivity
secondary productivity – rate of formation of new organic matter by heterotrophs
