Topic 8.5 - Community Ecology 𖦹⋆｡°✩

Question 1

what is the structure of a community described according to

Answer 1

described according to species composition and diversity

Question 2

what is a community

Answer 2

a group of different species living together in the same location and interacting with one another

Question 3

what are communities described based on

Answer 3

༻ species diversity
༻ species composition

Question 4

what is species diversity

Answer 4

the variety of species and the quantity of individuals included in each species within a given community

Question 5

what is an example of species diversity

Answer 5

an ocean community consists of one species of shark and one species of sea turtle, yet there are 15 sharks and 62 sea turtles

Question 6

what is species composition

Answer 6

the identity of each species in the community

Question 7

what is an example of species composition

Answer 7

an ocean community consists of Pomacanthus paru and Pomacanthus xanthometopon, two species of angelfish

Question 8

what is the Simpson’s Diversity Index

Answer 8

an equation used to measure the biodiversity of a habitat

Question 9

what does it mean if there is a higher diversity index value

Answer 9

the community is more diverse

Question 10

what sample of an environment is used to calculate the diversity index

Answer 10

random samples of the environment

Question 11

what does a community changing over time depend on

Answer 11

interactions between populations

Question 12

what is one type of interaction that can affect how populations access energy and matter

Answer 12

competition

Question 13

what can competition result in

Answer 13

in a change in community structure

Question 14

between whom can competition arise

Answer 14

can occur with or between species competing for food and habitats

Question 15

what are the two types of positive interactions

Answer 15

༻ mutualism/symbiosis - both species benefit
༻ commensalism - one species benefits but the other is not harmed

Question 16

what are the two types of negative interactions

Answer 16

༻ predator-prey - one species uses another as a food source
༻ parasitism - one species benefits at the harm of another

Question 17

what affect do neutral interactions have and provide an example

Answer 17

have no impact on the species involved. for example, deer or rabbits living in a forest

Question 18

what determines how populations access energy and matter

Answer 18

interactions among populations

Question 19

what is an example of populations interacting with one another. explain

Answer 19

bracket/shelf fungi are tree parasites with 4 main functions:
༻ produce fruiting bodies that grow on tree bark
༻ absorb nutrients from the outer bark, which can weaken the external tree structure. however, reduced canopy and reduced foliage density can free up resources. on the other hand, it can infect the tree’s interior which may rot the tree and cause branches or the entire tree to fall. this provides new niches and habitats
༻ provide microhabitats for bugs since they can live in the holes the fungi make in the tree bark
༻ provide a food source for insects and other organisms because some insects use fungi as a food source

Question 20

how can the relationships among interacting populations be modeled

Answer 20

can be characterized by positive and negative effects and modeled

Question 21

what would an increase in predator populations be seen

Answer 21

an increase in predator populations occurs slightly after an increase in prey populations, but will eventually cause a decrease in prey populations

Question 22

what is a trophic cascade

Answer 22

the negative effect the removal of or decrease in a key species has on other trophic levels

Question 23

what will happen to the population as a result of the removal of a key species

Answer 23

populations can experience exponential growth or death, which results in the interruption of the flow of energy through the ecosystem and resource availability

Question 24

what is niche partitioning

Answer 24

a decrease in competition over limited resources between two similar species because each species is accessing the resource in different ways

Question 25

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