Lecture 9 Flashcards
Define: Interspecific competion
Species compete for a limited resource.
Define: Resource partitioning.
The differentiation of niches that allow two similar species to coexist in a community.
Eg. One species lives in the top of a tree and eats the leaves and another similar species lives in the bottom branches and eats the bark.
Define: Character displacement
The difference in characteristics between populations of two species is greater in species whose territories/areas overlap than those that do not.
Define: Cryptic colouration
(Camouflage) Makes prey difficult to see against the background.
Info: Aposematic colouration
Animals with chemical defenses exhibit bright colours as a warning.
Define:Batesian mimicry
A harmless, palatable species mimics a harmful, unpalatable species.
Define: Mullerian mimicry
Two or more unpalatable species closely resemble one another. This increases the apparent number and makes it more likely for a predator to encounter them and learn to avoid that prey and all that look like it.
Define: Parasitoidism
The parasite, usually an insect, lays eggs in or on a living host.
Define: Pathogen
A disease-causing agent which has a harmful effect on the host. (+/-)
Define: Mutualism
Both species benefit from their interactions.
Define: Commensalism
One species benefits from the interaction and the other is neither helped nor harmed. (+/0)
Remember: Species diversity
The variety of different species that make up a community.
Define: Species richness
The total number of different species in the community.
Define: Relative abundance (of the different species)
The proportion of each species out of the total individuals in the community.
Define: Trophic structures
Structure of a community based on the feeding relationships between organisms.
Info: Food webs
Are food chains with the links between all organisms showing creating complicated structures.
Define: Keystone species
Are hugely influential within their community structure because of their ecological niche. If removed, community structure will be affected and this is often in a negative way.
Info: Top-down and bottom-up controls
The structure of a community is either controlled from the bottom-up by nutrients or the top-down by predators.
Define: Intermediate disturbance hypothesis
Moderate levels of disturbance can create conditions that foster greater species diversity than low or high levels of disturbance.
Define: Ecological succession
The sequence of community changes after a disturbance.
