Community Ecology Flashcards
Define Community
a group of actual/ potential interacting species living in the same location
What are the 4 main times of community interactions?
Competition
Predation (+ parasitism)
Mutualism
Commensalism
Which type of community interaction has a negative effect on both populations?
Competition
Which type of interaction benefits one population whilst the other is unaffected
Commensalism
Which type of interaction benefits both species?
Mutualism
Which type of interaction benefits one population and negatively impacts the other?
Predation/ parasitism
Define intraspecific and interspecific competition
inTRAspecific = competition among members of the same species inTERspecific = competition between members of two or more different species
explain the 2 types of interspecific competition
Exploitation competition = when individuals exploit or consume the same limiting resources - depleting availability to others
Interference competition = when individuals interfere with the foraging or reproduction of others
Give an example of interference competition
- Animals may chase other individuals away from food resources
- Animals defending territories
- Plants producing allopathic chemicals to limit growth and survival of other plants
Name 3 limiting resources that may cause competition
Food Space Soil Mates Nutrients
Define competitive exclusion
when one species is displaced by another when their niches overlap and they compete for the same resources
What is an ecological niche?
It is the role and position a species has in its environment
What is resource partitioning?
when niches become separated to avoid competition for resources in species with similar ecological niches
Give an example of resource partitioning
Bumblebees – the length of the proboscises differs with each bumblebee species – allows them to specialize in the exploitation of plants with different length corollas
How can species adapt to avoid/ as a result of competition?
Specialisation
What is a fundamental niche?
the set of resources and habitats an organism could theoretically use under ideal conditions
What is a realised niche?
the set of resources and habitats an organism actually uses due to the effects of competition (compared to the fundamental niche which are the theoretical ideal conditions)
what is character displacement?
characteristics of an organism change to avoid competition
What are the 3 reasons character displacement can occur?
1) when populations of closely related species have the potential for competition
2) When species live in allopatry (separate ranges) or sympatry (overlapping ranges)
3) When there is pressure from competition from phenotypically similar species that can cause natural selection to favour the phenotypic divergence of individuals of the different species
what is sympatric speciation?
speciation that occurs when two groups of the same species live in the same geographical location but they evolve differently until they can no longer interbreed and are considered different species
What causes sympatric speciation?
Intraspecific competition
what are the 4 types of predators?
True predators
Grazers
Parasites
Parasitoids
what is aposematic colouration? and what is it for?
Animals with chemical defences often exhibit bright aposematic colouration – ‘warning colouration’ to warn predators that prey is unpalatable, toxic or dangerous.
It is a defence mechanism to avoid predation
What is a common example to a mutualistic (plant) relationship?
the relationship between fungal Mycorrhizae and most rooting plants
How does fungal mycorrhizae create a mutualistic relationship?
The fungi increases the plants ability to absorb nutrients
The host plant provides support and carbohydrates for the fungi
what is
Mutualistic symbiosis?
a type of mutualism in which individuals interact physically, or even live within the body of the other mutualistic
what is facultative vs obligate mutualism?
Facultative = not essential for the survival of either species. Obligate = is essential for the survival of one or both species
Give an example of commensalism
- Birds nesting in trees
- Nurse plants protecting seedlings
- Treefrogs using plants for protection and egg laying
- Golden jackal following a tiger to eat leftovers
