Lecture 5 (still) - Interspecific

Question 1

exclusion

Answer 1

isolines do not cross

species with biggest carrying capacity wins

Question 2

coexistence

Answer 2

isolines cross

coexist when intra effects are stronger (K inside)

Question 3

equilibrium

Answer 3

growth rate = 0
arrows point to joint equilibrium
small overlap in realised niches

Question 4

scramble (exploitive, consumptive)

Answer 4

shared resource, depleting
exploitation = depleting resources
pre-emptive = depleting space

Question 5

contest (interference, encounter)

Answer 5

overgrowth = growing over, deprive others of light
chemical = produce toxins
territorial = fighting in defence of space 
encounter = interactions directly over resource

Question 6

Bedstraws - Tansley

Answer 6

field experiment - calcerous vs acid soil

• grew 2 species alone/together
• resource = soil, space
• do better on their own

strong intra competition- isolates them into different habitats

Question 7

Beetles - Park

Answer 7

conditional outcomes of competition

• alter temperature, humidity
• inter vs intra changes as environment varies

Question 8

Barnacles - Connell

Answer 8

on sea shore, 2 species

• can grow nearly everywhere but don’t
• realised niches account for competition

Question 9

Darwin’s finches

Answer 9

resource size, traits change to allow co-existence

- evolution minimises interspecific competition

Question 10

MacArthur - warblers

Answer 10

warblers spend time and eat in different parts of conifer tree canopy

• shared resource use/space to acquire/time of day
• differ in traits related to resource doesn’t mean competition or trait evolution

Question 11

MacArthur coexistence

Answer 11

1. different resources
2. same resource, different times
3. same resource, different location
4. same place, different location

evolution of traits minimise overlap of habitat/resource use