Flashcards in Fill in the blanks for lecture 7 Deck (64):
The L-V competition model predicts _ potential outcomes of __-species competition
A modification to the L-V model came in 2000 by a fellow named Chesson: this was?
absolute competition coefficients, not relative based on K
alpha is the absolute __________ competition coefficient.
Beta is the absolute ________ competition coefficient.
Species coexistence occurs when _________ competition > _________ competition
intraspecific > interspecific
The L_V model can be expanded to include ________ species. This new form of the equation is: _ = ___.
This new equation is a _______, solved using ________.
2) K = AN*
3) Matrix; matrices
The L-V model is limited because it does NOT include _________.
How do competing species affect their _________.
How are population growth curves affected by _______ _________.
3) resource densities
Give an example (that we spoke of in class) of resource dependent consumer population growth rates.
Species with different rates of nitrogen conversion. The conversion efficiency is different, leading to different growth rates.
This is an example of resource dependent growth rates!
Draw the graphic representations of the one consumer - one resource graphs.
1) Per capita birth or death rate vs. resource availability
2) Consumer abundance and resource abundance vs. time
refer to notes (8)
Mortality rate is _______ regardless of resource.
Birth rate ________ with increasing resource.
R*, of the intersect of both the growth or mortality rate indicates what?
ZPGI based on resources
When we graph two consumers competing for one resource, we assume that the 2 species have the same _______ ______.
Draw the graph for per-capita birth and death rates vs. resource availability for 2 consumers competing for the same resource:
Where, species 1 requires more resource to support a stable population. Clearly indicate R* and R1*
refer to notes (9A)
Draw the graph for consumer abundance vs. time for two consumers competing for the same resource.
Refer to notes (9B)
When comparing the gleaner and opportunist species, the gleaner grows faster when resources are ______, the opportunist grows faster when resources are _________ and, coexistence occurs when resource availability ___________.
What is an essential resource?
-Required for growth
- 1 essential resource cannot be substituted for another
ex: nutrient and mineral resources
What is a substitutional resource?
Classified as such if one resource can take the place of another.
ex: different prey species may provide complete diet for a consumer
Tilman's competition model is based on _________ ___ of plant nutrients.
Diatoms often compete for _______ which is used to make _____ _____.
- cell walls
When species of diatoms are grown alone, when their densities increase what occurs?
Phosphate concentration decreases
When the two species were grown in competition, what was the outcome? Draw the graph.
What don't we know?
Asterionella eliminated cyclotella (competitive exclusion of other species is fine)
Refer to notes (16)
Don't know how or why this occurs.
To determine why one diatom species outcompetes the other, what was done?
ZNGI based on resources, silica and phohsphorus
Draw a ZNGI for 2 species and 2 resources.
Refer to notes (18)
What is the assumption for ZNGI?
assume that mortality rates are density-independent
At resource levels below ZNGI, what occurs?
Species does not grow, death. Not enough resource.
At levels above ZNGI, what occurs?
Increase in growth.
What needs to be known to predict the outcome of resource competition? (4)
1) Reproductive or growth rate of each species to the resource
2) Mortality rate of each species
3) Supply rate of each resource (S)
4) Consumption rate of each resource by each species (C)
Consumption rate of a resource is given by?
Supply rate of a resource is given by?
Above both ZNGI, what occurs?
If below the ZNGI of one species, what occurs?
2) Competitive exclusion of the other species
Tilman's model outcome depends on 4 things, these are?
1) Resource dependent growth
2) Resource supply rates
3) Resource consumption ratios
4) Mortality rates of each species (m)
What is the strength of Tilman's model?
The emphasis on the mechanism and so helps us to understand species interactions with limited resources.
Apparent competition is what?
Non-competing species that share a common predator may have negative indirect effects on each other.
What is the assumption of apparent competition?
Predator abundance is dependent on total prey abundance.
For the 1st experiment with moths and parasitoids (alone), each host maintained what?
A population in the presence of the parasitoid.
In the second experiment, where both moth species and the common parasitoid species were combined, what occured?
3 species interactions never persisted. Once one host was eliminated, reached stable equilibrium.
The presence of the plodia species, caused increased _______ of ephestia.
__________ __________ may be a key process for structuring ecological communities.
Lab experiments confirm predictions of resource competition but, evidence from the _____ is _______.
evidence from the field is limited
What are the general comments on testing theory? (3)
1) Is the theory locally sound?
2) Do observations match the theory's predictions when the assumptions are met
3) Is the theory a powerful explanation of nature?
What are niche shifts?
Change in species diet or habitat use in presence or absence of predator.
Niche shifts may result from 2 things, these are?
Interspecific competition and predation (apparent competition)
Character displacement: a species' functional morphology _____ __ ___ ________ vs. _______ of a __________.
differs in the presence vs. absence of a competitor
Populations are more divergent in areas of _________.
______ __________ may be accompanied by character displacement.
For ground finches,
____ _____ correlates well with the size of the ______ that are eaten.
bill size; seeds
________ distribution: species do not co-occur
__________ distribution: more divergent beak sizes where the same species co-occur.
We see the ________ of habitat for the Anolis Lizard in the Greater Antilles.
For the Anolis species, patterns of morphological similarity __ ___ _____ the patterns of genetic similarity.
do not match
The data reveals distinct patterns for ________ and _______ use for lizards of Great Antilles.
morphology and habitat use
Anolis lizards on different islands are __ ______.
The most closely related Anolis species are not as similar in _______ or ______ ___.
morphology or habitat use
What provides the strongest observational evidence for interspecific competition?
Close competitors evolve to ______ size differences between them
How does one get experimental evidence for competition in the field?
Remove potential competitor and look for response in remaining species.
Describe the different tidal zones and which size of barnacle lives where. Also indicate the effect of predation.
The highest intertidal zone harbours the smaller barnacle, which is less susceptible to dessication.
The lower intertidal zone harbours the larger barnacles which aren't as susceptible to predation by the starfish.
In the middle interdital zone, the larger barnacle outcompetes the smaller barnacle
What occurs when the starfish is removed?
Both barnacles move down.
Barnacle species _______ intertidal zone based on reducing ________ competition.
What are the different designs for competition experiments?
1) Substitutive design
2) Additive design
3) Response surface design
What is a substitutive design?
Keep density constant regardless of treatment but, have the population composed of a different number of individuals of either species.
What is an additive design?
Maintain density of one species and incrementally increase the density of another species.