Chapter 14

List and define the 6 types of interactions that describe interspecific competition:

1. Consumption- resource consumption by one individual limits resource availability for other individuals 2. Preemption- occupation of space by one individual prevents occupation by other individuals 3. Overgrowth- one organism grows over another organism 4. Chemical interaction- chemicals produced by one individual to inhibit growth of other individuals 5. Territorial- individual defends its territory and its resources 6. Encounter- nonterritorial interactions negatively affect individuals

What are the 3 assumptions of the competitive exclusion principle?

1. Resources are limited 2. Competitors have the exact same resource requirements 3. Constant environmental conditions

What are the 4 outcomes of interspecific competition

1. Species 1 outcompetes Species 2, causing Species 2 to go extinct; Species 1 is the superior competitor while Species 2 is the inferior competitor 2. Species 2 outcompetes Species 1, causing Species 1 to go extinct; Species 2 is the superior competitor while Species 1 is the inferior competitor 3. The outcome of competition could go either way, with the species with the larger initial population size usually winning 4. Coexistence between Species 1 and Species 2

Competitive exclusion principle

2 species that live in the same place with the same resource requirements cannot coexist

How do trade-offs explain why the competitive ability of organisms vary across spatial and temporal environmental gradients

Being a good competitor for one resource (benefit) make a species a poorer competitor for another resource (cost). Furthermore, being a good competitor for one resource (benefit) can result in a low tolerance to environmental stressors (cost). As such, as the availability of multiple resources and environmental stressors change across space and time, so too does the competitive ability of species also change

What process creates resource partitioning in nature?

Coevolution

What is the name of the mathematical model that describes interspecific competition?

Lotka-Volterra Competition Model

Explain why measuring competition in nature is difficult

Measuring competition in nature is difficult because it's impossible for researchers to control the environment, researchers don't know if s pecies are at or near the carrying capacity, and researchers don't fully understand competitive differences among species. Furthermore, measuring competition in nature is difficult because competition is such a complex interaction, as it occurs among multiple species for multiple resources, is only one type of biotic interaction influencing species, and varies as environmental conditions change through space and time.

Does interspecific competition influence the fundamental or realized niche?

Realized niche

In general, what allows for coexistence among species with similar resource requirements?

Spatial and temporal variation in environmental conditions

Explain the idea of "Ghosts of Competition Past."

The "Ghosts of Competition Past" states that contemporary competition between individuals of different species is low because coevolution and resource partitioning resulting from historical competition reduced niche overlap and thus reduced competitive interactions.

When does competitive release occur in nature?

When a species colonizes a habitat that lacks competitors or when a competitor is removed from a habitat.

When does outcome #3 usually occur?

When interspecific competition is stronger than intraspecific competition

When does outcome #4 usually occur

When intraspecific competition is stronger than interspecific competitio

Can non-resource factors influence the outcome of competition? If so, provide some examples of non-resource factors.

Yes. Environmental factors that are not consumed, such as temperature, pH, and relative humidity, can influence the outcome of competition

Interspecific competition

competition for resources among individuals of different species

Intraspecific competition

competition for resources among individuals of the same species

Character displacement

competition results in a phenotypic shift in behavior, physiology, or morphology as a result of coevolution via natural selection

Is the following statement true or f alse? "Competition only occurs for one resource at a time."

false

Interference competition

one individual prevents other individuals from using a resource via territoriality

Competitive releas

one species expands its niche in response to a lack of competition from another species

Exploitation competition

resource consumption by one individual limits resources available for other individuals

Realized niche

the portion of the fundamental niche a species actually exploits as a result of biotic interactions

Fundamental niche

the range of environmental conditions under which a species can survive and reproduce and the range of resources that species uses

Ecological niche

the range of environmental conditions where a species can survive, grow, and reproduce, and the array of resources utilized by a species.

Is the following statement true or false? "The competitive abilities of organisms change as environmental conditions change

true

Resource partitioning

when 2 species use the same resource in different ways