Lecture 16 Flashcards
Equation for logistic model
dn/dt = rN (1 - N/K)
What is logistic model good for?
Good to model density-dependent growth
Competition coefficients
“quantify the intensity of competition between species for a shared limiting resource”
* Quantifies the effect of one species on another
* Describe how the growth of one species in affected by the abundance of another species
* Converts the number of individuals of one species into the number of individuals of the other
Symbiosis
“a type of mutualism in which individuals live within or on the other organism”
Obligate mutualisms
are essential for survival of one or both interacting species
Facultative mutualisms
not essential for the survival of either species
Mycorrhiza
symbiotic association between a fungus and a plant
* More mycorrhizal fungal species are associated with increases in plant phosphorus, root biomass and shoot biomass.
Coral-algae mutualisms
Sybiotic relationships between corals and various microoorganisms, particularly photosynthetic algae known as zooxanthellae
Zooxanthellae
- photosynthesize and share sugars with the coral host
- Corals provide zooxanthellae with essential nutrients
- Zooxanthellae contribute a significant proportion of the coral’s energy needs, aiding in calcification or coral skeleton.
Defense mutualisms
- Trade defense for energy
Trophic mutualisms
- Trade food (energy) for nutrients
- Trade food (energy) for food (energy)
Transport mutualisms
- Trade transport for energy
(Seed dispersal; pollination)
Seed dispersal mutualisms
Mutualistic associations between plants and animals
Pollination mutualisms
Mutualisms between flowering plants and pollinators (insects, birds, bats, or other animals)
Causes for pollinator decline
- Habitat diversity loss (monocultures which all flower at once)
- Agro-chemical use (herbicides)
- Competition from domesticated honeybees or other introduced pollinators
