2: Competition Flashcards
When do individuals compete?
When resources are limiting
Give some examples of resources in an ecosystem
Food
Shelter
Climate
Nutrients
Territory
Mates
Describe indirect competition
Exploitation/scramble → depleting resources
Pre-emptive → using space (depleting space)
COST: loss of resource
List some examples of interference competition
Overgrowth → species growing over another and depriving the other of light
Chemical → production of toxins
Territorial → behaviour / fighting in defence of space
Encounter → transient interactions directly over a specific resource
COST: Loss of resource as well as cost of fighting
In interspecific competition, what should happen to K?
gradient could decrease / K should decrease
Describe George Gaus’ competitive exclusion principle experiment
2 species of Paramecium
- Jar 1 species A, Jar 3 species B (intraspecific)
- Jar 2 species A + B (interspecific)
Conclusion: No 2 species can share the same resource, eventually one will out-compete the other
Describe a fundamental niche
(pre-interaction)→ intrinsic requirements of a species on its own e.g temp limits, food
Describe a realised niche
(post-interaction) → what happens to limits when other species are around
No two species can occupy the same ______
niche
Describe the Competitive exclusion principle
No 2 species can share the same resource
No 2 species can occupy the same niche
2 species cannot coexist when they have identical needs of a limited resource
On a competition graph, what happens when the isoclines cross?
No 2 species can share the same resource
No 2 species can occupy the same niche
2 species cannot coexist when they have identical needs of a limited resource
On a competition graph, what happens when the isoclines cross?
When the isoclines cross → equilibrium reached = coexistence!
On a competition graph, what happens when the isoclines do NOT cross?
One species will be excluded, the species with the biggest carrying capacity wins!
Coexistence only happens when…
when the intra-specific effects are stronger (K’s Inside) than inter-specific effects
K’s inside = closer to 0 → stronger regulating effect
