Evs 1210 Population Regulation (Pp)

Front 1

Ecological niche

Back 1

is the role of any organism in any given ecosystem, assumes a specific habitat, community or stage in succession of a community

Front 2

3 facts about ecological niche (3)

Back 2

assumes an obligate relationship with one or

more species of plants and animals

result of long-term genetic adaptation

most organisms are “locked into” their niche

Front 3

Specialists (4)

Back 3

tolerate only specific environmental conditions

feed on a limited type of food

can usually outcompete other species for their designated food source

if their food source disappears they may be too specialized to use other food sources

Front 4

Generalists (3)

Back 4

adaptable to different environments and food sources

usually in less danger of becoming extinct when conditions variable

can usually out-compete a speicalist for a specific food source

Front 5

Infraspecific population regulation

Back 5

competition, dispersal, territoriality

Front 6

Competition

Back 6

Occurs when resources are limited, 2 responses scramble and contest

Front 7

Scramble competition

Back 7

growth and reproduction are depressed equally (possible death)

Front 8

Contest competition

Back 8

some individuals claim more resources (faction of population eliminated)

Front 9

Effects of competition (4)

Back 9

growth and development, increase mortality rates, reduced rates of production, high density can be stressful to individuals

Front 10

Dispersal

Back 10

in response to high population density does not effectively regulate population

due to lack of resources is usually sub-adults driven out by adult aggression

Most common when population is high(density dependent)

but can occur all the time

Front 11

Why is dispersal important

Back 11

relocated to area with more resources, reduced risk of inbreeding, less competition for parent (plants), contributes to expansion, aid in persistence

Front 12

Home range

Back 12

area an animal normally covers during lifetime, influenced by body size

Front 13

Territoriality

Back 13

animal or group defends a part or all of its home range

Front 14

metapopulations

Back 14

due to environmental variability, most populations divided into sub populations

Front 15

Population vs metapopulations

Back 15

Population: individuals of the same species occupying the same place at the same time



Metapopulation: a collection of local populations interacting within a larger region

Front 16

Conditions of metapopulations (4)

Back 16

Suitable habitat occurs in discrete patches thatmay be occupied by local breeding populations Even the largest local population has risk of extinction

Habitat patches are not so isolated that recolonization can’t occur after local extinction

Dynamics of the local populations are not synchronized

Front 17

Metapopulation persistence (3)

Back 17

Depends on, patch size and isolation

Probability of local extinction increases with smaller patch size and increased isolation

Probability of colonization increases with patch size and reduced isolation

Front 18

Local population persistence (5)

Back 18

habitat heterogeneity, large population size in a neighbouring patch, increased number of local populations, species dispersal rate, body size