community ecology

what is ecological community

group of species that coexist and interact in defined area

how is the number of species in a community determined

available energy

what is biomass

sturdy community on basis of energy

what are primary producers

convert sunlight to chemical energy, autotrophs, consumed by heterotrophs

what is the gross primary production

amount of stored chemical energy from photosynthesis, isn’t completely available to consumers.

what is net primary production

what is available to consumers

what has an impact on the distribution of global GPP

water and sunlight, affects where producers can grow

how are tropic levels made

made by what eats what, not random, dynamic

how much energy at one tropic level is transferred to the next, ecological efficiency

about 10%

why is energy lost at each level

heat, not all is accessible, some is hard to digest

why are communities only able to support 3-5 tropic levels

energy loss at each transfer

how does the arrangement of tropic levels impact reproduction, population size and body size

going up- the reproduction rate lowers, population size decreases, body size increases

why is there more primary consumers in the grassland than forest

trees have parts that are indigestible

why is the open oceans primary consumers bigger than primary producers

high division rate of algae supports high consumer population

what limits productivity and how does water impact if not limited

sunlight/energy available, more water leads to higher productivity so more species

when does diversity of animals decline

at very high levels of productivity, due to competitive exclusion

what is a trophic cascade

interaction of one consumer with other species has indirect effects on others

what is a species that has disproportionate influence on a community, what do they influence

keystone species, species richness, trophic levels, increase resources that would be limited

what impacts species diversity and what has the greater impact

richness and evenness, evenness

what is alpha diversity

looking at a single community

what is beta diversity

looking at multiple communities

what diversity would rivers have

low beta

what diversity would ponds have

high beta

what diversity would ditches have

low alpha

what determines how diverse a community is

distance from equator, energy or water supporting primary productivity, size of land mass

what islands have greater diversity

large, species-area relationship

how is the number of species on an island balanced

immigration and extinction, at equilibrium when equal

how can fire help seeds germinate

melts resin, karrikin

what is the difference between primary and secondary succession

p-after large-scale event, glaciers s-more localized, quick

how can species richness influence community stability

more species, more susceptible to disturbances