Midterm 2 Terms and Definitions

Question 1

Character Displacement

Answer 1

Shift in one or both competing species resources use thereby decreasing niche overlap

Question 2

Climax Community

Answer 2

A community that occurs in late succession and whose population remain stable until disrupted by disturbance
K SPECIES

Question 3

Community

Answer 3

An association of interacting species living in particular area, often defined as all organisms living in particular area

Question 4

competitive exclusion principle

Answer 4

a theory that states 2 species with similar ecology CANNOT coexist

Question 5

disclimax community

Answer 5

community whose species composition is maintained through time by frequent disturbances, like drought or grazing

Question 6

disturbance

Answer 6

any relative discrete event disputing an ecosystem, community, or population structure and changes resources, substrate availability or physical environment

Question 7

equilibrium

Answer 7

state of balance in system which opposing factors cancel each other, stability is maintained by opposing forces such that populations altered by events quickly return to equilibrium state

Question 8

facilitation model

Answer 8

model of succession which pioneer species modify environment in ways that it becomes less suitable for early successional species and more spottable for species characteristic of later successional stages

Question 9

functional response

Answer 9

increase in animal feeding rate which eventually levels off, occurs in response to increase of food availability

Question 10

gross primary production

Answer 10

total amount of NRG fixed by all photoautotrophs in ecosystem

Question 11

gross secondary production

Answer 11

total amount of NRG entering tropic level through ingestion by consumers

Question 12

handling time

Answer 12

total amount of time taken to chase, kill and digest a particular type of prey

Question 13

inhibition model

Answer 13

model of succession that proposes that early occupants of an area modify environment in a way that makes area less suitable for both early and late successional species

Question 14

insurance hypothesis

Answer 14

theory that increased diversity community stability due to an increased portability of there being some species present in the community able to cope with any particular disturbance

Question 15

net primary production

Answer 15

gross amount of NRG from primary production minus amount of NRG lost via respiration by photoautotrophs

Question 16

net secondary production

Answer 16

point of NRG energy trophic level through ingestion by consumer, minus NRG lost to reparation (heat), excretion and urine

Question 17

numerical response

Answer 17

change in density of predator pop in reposes to increased prey density

Question 18

optimal foraging theory

Answer 18

through that attempts to model how organisms feed as an optimizing process that maximizes or minimizes some quantity, like NRG intake or predate risk

Question 19

Pioneer community

Answer 19

first community to become established following disturbance, with species commotion of community changing over time, typically composed of R SELECTED

Question 20

pioneer plant communities

Answer 20

typically composed of species that can colonize bare rock, disperse over bast distances and can fix nitrogen

Question 21

primary productivity

Answer 21

amount of NRG fixed by photoautotrophs per unit time- low NRG inorganic carbon to high NRG organic carbon product

Question 22

primary succession

Answer 22

succession on newly exposed geological substrate, not significantly modified by organisms- ex. newly formed volcanic lava or on substrate exposed bu retreat of glaciers

Question 23

resource partitioning

Answer 23

when species split or divide recourses to avoid or lessen competitive overlap

Question 24

secondary production

Answer 24

assimilation of organic matter by heterotrophs to produce biomass

Question 25

secondary succession

Answer 25

succession where disturbance has destroyed community without destroying soil- ex. forest succession after forest fire or logging

Question 26

stability

Answer 26

absence of change- may arise from lack of disturbance or communitys ability to withstand or recover from disturbance

Question 27

standing crop

Answer 27

total biomass or number of each size class of consumers present at particular trophic levels

Question 28

succession

Answer 28

gradual change in plant and animal communities in areas following disturbance or creation of NEW substrate

Question 29

tolerance model

Answer 29

model of succession which initial stages of colonization are not limited to few pioneer species; juveniles of species donating at climax can be present from earlier stage of succession and species colonizing early in succession do NOT facilitate colonization by species characteristics of later successional stage. Later successional species are simply those tolerant of environmental conditions in succession

Question 30

trophic level

Answer 30

trophic position in ecosystem like- primary producer, primary consumer, secondary consumer, tertiary consumer, etc.