species interactions: module 4 Flashcards
what is competition? explain
- both species are supressed in terms of their population growth by their interaction with the other species
- negative, negative interaction
- both species suffer
- usually occurs when both is competing for a limiting resource
- usually expected to occur when the niche of two species overlaps with each other
- likely to reduce the size of the realized niche
what are exploiative interactions?
- one species benefits at the expense of the other one
- positive negative interaction
- can include predation, parasitism, and herbivory
- predators: kill their prey
- herbivores and parasites: usually don’t kill their prey, but can lead to increasing chance of mortality, or can affect their victims through reduced reproduction
What is mutalism interaction?
- both species benefits or one species benefits, and the other one is not affected
- positive positive or positive nothing
what is amensalism interaction?
- one species suffers, but the other one recieves no benefits
what is a niche?
- the set of conditions under which a species can persist (meaning the populations have to be self replacing)
- conditions can include: climatic factors (temp, precipitation, solar radiation, wind)
what is a fundamental niche?
the set of abiotic conditions under which a species can occur
what is a realized niche?
the interaction between species can restrict the species to only certain parts of its fundamental niche, which is what a realized niche is
what in interference competition?
- involves direct antagonistic behavioural interactions between competing species
what is exploitative competition?
where a species negatively effect each other through the use of a shred, limiting resource, but may never actually interact
describe the competition between the blowflies and the houseflies example.
- there was a strong selection on blowflies to be more competitive on houseflies
- there was a strong selection on the housefly population to favour traits that would allow it to be more competitive with each other
why would selection favour resource partioning?
- reduces the intensity of competition between species
- reveals traits in which species compete each other for
what is the concept of character displacement?
- if two species overlap in resource use, then over time natural selection will favour decreased overlap in resource use
- selection would favour members of one species that tend to consume resources that are not heavily used by members of the other species, and vise versa
Describe the concept/act of herbivory.
- herbivory transmits the suns energy from the primary producers up through the food chain
- involves resistance and tolerace: evolutionary solutions to herbivory
- resistance: mechanisms that prevents herbivores from attacking a plant
- tolerance: mechanisms where the plant can experience herbivory, with minimal reduction in fitness
- use a variety of morpholgical and chemical traits for resistance
what are trichomes? what is their connection to plants and herbivory?
- glandular and simple trichomes exist
- important mechanisms of herbivore resistance
- provide physical and chemical defense for plants
- a resistance trait, since it prevents herbivores from damaging the plant
why would a plant release volatile chemicals?
- warn surrounding plants about a herbivore attack and attract the predators and parasites of the herbivore
- this reduces the number of herbivores on an individual plant
- multi trophic interactions
- resistance to exploitation example
