17: Species Abundance & Diversity-Community Structure Flashcards Preview

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Flashcards in 17: Species Abundance & Diversity-Community Structure Deck (35)
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1

community composition

mix of species, including their number and relative abundance, within a set area

2

attributes of diversity

species richness and relative abundance

3

What pattern do most communities illustrate?

few common species with many rare ones

4

Relative abundance

the percentage each species contributes to the total number of individuals

5

how can we graphically compare two community diversity?

rank-abundance curves

6

step one of rank-abundance curve

sort table based on rank from high to low

7

step two of rank-abundance curve

calculate relative abundance of each species in the community

8

step three of rank-abundance curve

draw graph with rank on x-axis and relative proportion on y-axis

9

step four of rank-abundance curve

repeat for control group

10

gradual slope on rank-abundance curve

greater species evenness

11

species evenness

equitable distribution of individuals among species. highest when all species have the same abundance

12

problems with graphically comparing two communities

graphs represent qualitate comparison, but often requires a quantitative comparison

13

Diversity Indices

Shannon-Wiener Index. The higher the number, the higher the diversity

14

types of diversity

alpha, beta, and gamma

15

alpha diversity

within-habitat diversity

16

beta diversity

between-habitat diversity (changes along an environmental gradient)

17

gamma diversity

large-scale landscape diversity (combines alpha and beta diversity)

18

How is Species Diversity related to Ecosystem Services

directly proportional

19

where in the globe is diversity typically highest? lowest?

highest in tropics, lowest at poles

20

factors that influence diversity

habitat complexity, environmental complexity, disturbances

21

disturbance

A discrete punctuated killing, displacement, or damaging of one or more individuals that directly or indirectly creates opportunities for others

22

Intermediate Disturbance Hypothesis

Predicts that intermediate levels of disturbance promotes higher diversity

23

Biggest disturbance to biodiversity

Humans

24

overall decline in wildlife population between 1970 and 2010

52%

25

species richness

number of species in a community

26

species diversity

combination of number of species and relative abundance of each species in a community; usually described as an index

27

community structure

all the interactions among species

28

food webs

describe trophic interaction between species and thus describe community structure. arrow points from prey to predator

29

food chains

subset of trophic interaction within a food web. simple and linear and often collapse species into trophic levels

30

trophic levels

obtain their energy in a similar manner (primary producers