Ecology Final

Front 1

geometric growth

Back 1

population of a species changes in size by a constant proportion

Front 2

exponential growth

Back 2

population of a species with continuous reproduction changes in size by a constant proportion at each instance in time

Front 3

net reproductive rate

Back 3

the mean number of offspring produced by an individual during its lifetime

Front 4

density-independent

Back 4

factors such as temperature, precipitation, and catostrophic events that determine population size
-these effects on the birth and death rates are independent of the number of individuals in the population

Front 5

density-dependent

Back 5

they cause birth and death rates, and dispersal rates to change as the density of the population changes
-as density increases it is common for birth rates to decrease, death rates to increase, and emigration to increase- all of which tend to decrease population size

Front 6

population regulation

Back 6

when one or more density-dependent factors cause population to increase when numbers are low and decrease when numbers are high.
-when the density of any species becomes high enough factors decrease population size because food, space, and other essential resources are in short supply

Front 7

logistic growth

Back 7

the abundance increases rapidly at first, then stabilizes at carrying capacity
-the growth rate of the population begins to decrease as the population size nears carrying capacity because essential resources are in short supply

Front 8

ecological footprint

Back 8

the total area of productive ecosystems required to support that population
-environmental impact of a population

Front 9

jump dispersal

Back 9

a long-didtance dispersal event in which a species colonizes a new geographic region

Front 10

population fluctuations

Back 10

population sizes rise and fall over time
-some populations that size increases or deacreases in abundance from and overall mean value
-in other populations fluctuations occur as deviations from a population growth pattern, such as exponential or logistic growth.

Front 11

population cycles

Back 11

alternating periods of high and low abundances occur after nearly constant intervals of time

Front 12

delayed density dependence

Back 12

delays in the effects that density has on a population size
-can contribute to population fluctuations

Front 13

damped oscillations

Back 13

the deviations from the carrying capacity gradually get smaller over time

Front 14

stable limit cycle

Back 14

the population exhibits a cycle in which fluctuates indefinately about the carrying capacity

Front 15

demographic stochasticity

Back 15

chance events related to the survival and reproduction of individuals

Front 16

Allee effects

Back 16

occurs when the population growth rate decrease as the population decreases perhaps because individuals have difficulty finding mates as low population densities

Front 17

environmental stochasticity

Back 17

erratic or unpredictable changes in the environment

Front 18

competition

Back 18

an interaction between two species in which each is harmed when they both use a resource that limits their ability to grow and reproduce

Front 19

intraspecific competition

Back 19

competition occurs between individuals of a single species

Front 20

interspecific competition

Back 20

competition between different memeber of different species

Front 21

physical factors

Back 21

features of the environment that affect population growth rates but are not consumed or depleted

Front 22

exploitation competition

Back 22

occurs in which species compete indirectly through their mutual effects on the availibility of a shared resource

Front 23

interference competition

Back 23

which occurs when species compete directly for access to a resource that both require, such as food or space

Front 24

allelopathy

Back 24

individuals of one species releases toxins that harm individuals if other species

Front 25

competative exclusion principle

Back 25

two species that use a limiting resource in the same way cannot coexist indefinately

Front 26

resource partitioning

Back 26

differences in how species used limiting resources

Front 27

Lotka-Volterra Competition Model

Back 27

a model used to explain that competative exlusion is likely to happen when competing species require very similar resources

Front 28

competition coefficient

Back 28

constants that describe the effect of one species on the other

Front 29

zero population growth isoclines

Back 29

the population does not increase or decrease in size for any combination of N1 and N2 that lies on these lines

Front 30

stable equilibrium point

Back 30

a combination of densities of the two species that once obtained, does not change over time

Front 31

fugitive species

Back 31

species that must disperse from one place to another as environmental conditions change

Front 32

character displacement

Back 32

occurs when competition causes the forms of competing species to evolve to become more different over time

Front 33

exploitation

Back 33

a relationship in which one organism benefits by feeding on, and thus directly harming, another

Front 34

herbivore

Back 34

eats the tissues or internal fluids of living plants or algae, often feeding on many different kinds of individuals

Front 35

predator

Back 35

kills and eats other organisms, referred to as its prey

Front 36

parasite

Back 36

typically lives in or on another organism (its host) feeding on parts of the host, such as its tissue or bodily fluids

Front 37

parasitoids

Back 37

insects that typically lay one or few eggs on or in another insect

Front 38

warning(aposematic) coloration

Back 38

species that contain powerful toxins are brightly colored and use this to provide itself protection from predators

Front 39

mimicry

Back 39

resembling less palatable organisms or physical features of their environment

Front 40

crypsis

Back 40

species that have a shape or coloration that provides camouflage

Front 41

compensation

Back 41

occurs when removal of plant tissues stimulates the plant to produce new tissues, allowing for relatively rapid replacement of the material eaten by herbivores
-when exact compenation occurs, herbivory causes no net loss of plant tissue

Front 42

secondary compounds

Back 42

plants produce a wide variety of chemicals tha function to reduce herbivory