unit 2 - ecology Flashcards
(48 cards)
what is an ecological community?
an association of species that live in the same area and is characterized by diversity (just biotic)
what is relative species abundance-how does this relate to ecological diversity?
how common one species is compared to another, higher relative species abundance the more diverse an ecological community is
food chain vs food web
food chain is a direct line of who eats whom and food web is a bunch of food chains combined
what is a keystone species
a species on which other species in an ecosystem largely depend
what happens when you remove a keystone species
there is a dramatic change (eg. wolf extermination in led to massive decline in aspens due to boom in omnivores)
what are the four major examples of species interaction, think of example for each
mutualism (both species benefit, bison:magpie)
commensalism (one benefits, other is not affected, magpie:tree)
predation (one benefits other is harmed, wolf:elk)
parasitism (one benefits, predator, other is harmed, host; predator lives on host; mosquito:human)
ecosystem vs ecological community
ecological community is just the living, biotic factors and ecosystem is the living, biotic, and nonliving, abiotic factors
nutrients vs energy when moving through an environment
nutrients cycle and energy flows in one direction and is lost in ecosystem as heat
define trophic levels
a level of the energy pyramid that corresponds to a step in the food chain
what role do plants have in an energy pyramid
primary producers (support whole food chain, bottom of food chain)
what role do omnivores have in an energy pyramid
primary consumers (second level of food chain)
what role do carnivores have in an energy pyramid
secondary consumers (third level of food chain)
what is the 10% role
only ~10% of energy is passed up to the next trophic level
define primary productivity
the rate at which primary producers photosynthesize
population size vs population density
population size is number of individuals in a population and population density is the population per unit area (ratio)
logistic vs exponential growth
exponential growth rapidly increases whereas logistic growth accounts for the carrying capacity and other environmental resistance
what is a carrying capacity
the maximum population size of a biological species that can be sustained by that specific environment
give some examples of density-dependent factors that change population growth
disease, resources, predation
give some examples of density-independent factors that change population growth
weather patterns, natural disasters, pollution
what role do decomposers have in the flow of nutrients?
break down dead bodies, returning nutrients to abotic world to restart nutrient cycle
state and define the two factors in every ecosystem
abiotic (non-living factors), biotic (living factors)
how do nutrients move through an ecosystem
pass through abiotic then biotic world and back through decomposers (reused and recycled)
how does energy move through an ecosystem
recieved and lost, bottom to top
which trophic level has the largest amount of energy
producers
