Chapter 54: Community Ecology Flashcards Preview

Bio 94: Exam 3 > Chapter 54: Community Ecology > Flashcards

Flashcards in Chapter 54: Community Ecology Deck (36)
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What is biodiversity?

The variety of life across all levels of biological organization

- genetic diversity
- species diversity
- ecosystem diversity


What is genetic diversity?

Varying genes that make up the characteristics of a species


What is species diversity?

Number of different species in a particular region

Two parts:
Species richness
Species evenness


What is ecosystem diversity?

Variety of habitats and communities in the world


What is species richness?

The number of species


What is species evenness?

The relative abundance of the species in that environment

(How many there are for that environment)


Answer the following for each location:
a) What is the species richness?
b) What is the species evenness?

Location 1:
- One tree
- Nine of the same shrub

Location 2:
- Five of the same tree
- Five of the same shrub

Location 1:
a) Species richness = 2
b) Species evenness = low

Location 2:
a) Species richness = 2
b) Species evenness = high


What does the Berger-Parker Index say about diversity?

The sample with greater evenness is more diverse than the sample with greater richness


How are community interactions classified?

By whether they help, harm, or have no effect on the species involved.


What are the 4 community interactions?

1. Competition
2. Predation
3. Herbivory
4. Symbiosis
- parasitism
- mutualism
- commensalism


What is competition?

When two or more species try to obtain the same limited resources


What is predation?

An interaction between species where the predator kills the prey


What is herbivory?

When plants are consumed by animals


What is symbiosis?

When individuals of 2 or more species live in direct and intimate contact with one another


What is parasitism?

When one organism feeds on the other (host)
- host receives no benefit


What is mutualism?

When both individuals benefit from the relationship

E.g., ants feed off of acacia plants for nutrients, and the acacia plants are protected by the ants.


What is commensalism?

An interaction in which one species benefits and the other is neither benefited or harmed

E.g., birds nest in trees, tree is not benefited or harmed.


What are hitchhiking species?

Species that partake in commensalism on the go.

E.g., algae on turtle shells, barnacles on whales etc.


Does competition have a positive or negative effect on both species?

Negative on both


Does predation have a positive or negative effect on both species?

Positive for the predator
Negative for the prey


Does parasitism have a positive or negative effect on both species?

Positive for the parasite
Negative for the host


Does mutualism have a positive or negative effect on both species?

Positive on both


Does commensalism have a positive or negative effect on both species?

Positive for one species
Neither +/- for other


What is the competitive exclusion principle?

Principle which states that the species that acquires more of the resources will win and the other species will die out


How are species able to coexist?

Both species will confine themselves to a particular niche in the same environment

E.g., there are two types of barnacles. Barnacle type 1 lives on the part of the rock that receives high tide. Barnacle type 2 lives on the part of the rock gang receives low tide. If barnacle type 2 was absent, barnacle type 1 would cover the entire rock, however, they are coexisting together.


What is resource partitioning?

When similar species focus on different resources/niches in order to coexist in a community

E.g., multiple bird species can live in the same tree. Some with live at the top of the tree while another lives in the middle.


What is character displacement?

When a species in a habitat will diverge because competing for a specific niche has restricted them to specific resources


What are 4 characteristics that prey can do in order to prevent themselves from being eaten?

Warning coloration
Chemical defenses


What is cryptic coloration?

Camouflage, where the organisms appearance can blend in with a background.


What is warning coloration?

Aposematic coloration

When an organism will physically change its color in order to show or pretend it is venomous to frighten the predator away