lecture 24

Question 1

biological community

Answer 1

a group of populations of different species that co occur in a geographic area

Question 2

species composition

Answer 2

mix of species in the community

Question 3

community structure

Answer 3

which species, how many, and how abundant

Question 4

spatial turnover

Answer 4

the change of species across space often occurs along environmental gradients, such as elevation or soil

Question 5

what determines the habitat structure

Answer 5

plant community

Question 6

habitat structure

Answer 6

3 dimensional distribution of objects that you have in a habitat

Question 7

what is the temporal composition

Answer 7

extinction and colonization

Question 8

disturbance

Answer 8

abrupt environmental change (fires, volcano, hurricane)

Question 9

succession

Answer 9

after a disturbance and some animals were killed, succession is the predictable sequence of changes in community composition over time

Question 10

temporal turnover

Answer 10

change in biodiversity over time in species composition due to global change

Question 11

species diversity has two components

Answer 11

species richness and species evenness

Question 12

species richness

Answer 12

total number of species

Question 13

species evenness

Answer 13

relative abundance of each species

Question 14

theres more diversity in what part of the world

Answer 14

equator

Question 15

what are the four hypothesis for latitudinal diversity gradient

Answer 15

1. species-energy hypothesis 2. geographic area 3. evolutionary rate 4. historical perturbation

Question 16

species energy hypothesis

Answer 16

solar energy and water availability increases productivity

Question 17

geographic area hypothesis

Answer 17

the tropics are the largest biome and that tropical areas therefore can support more species and species with larger ranges are less likely to go extinct

Question 18

evolutionary rate hypothesis

Answer 18

higher evolutionary rate means that you have higher speciation rates and thats going to lead to increased diversity (higher temps causes increased mutation rates)

Question 19

historical perturbation hypothesis

Answer 19

at higher latitudes there hasnt been enough sufficient time to colonize or recolonize these areas because of historical perturbations like ice age

Question 20

theory of biogeography

Answer 20

species richness on islands is a function of immigration (colonization) and extinction and will level off at dynamic equilibrium point

Question 21

islands can only gain species from

Answer 21

near by islands or the mainland

Question 22

as the island fills up, youre going to see the

Answer 22

colonization rate decline

Question 23

what increases as island fills up

Answer 23

rate of extinction

Question 24

larger islands will have higher

Answer 24

equilibrium points

Question 25

how are the colonization rate in farther islands

Answer 25

are lower compared to closer islands

Question 26

fragmentation causes species loss due to 3 reasons

Answer 26

1. total amount of habitat decreases 2. size of habitat patches decrease 3. patches become more isolated

Question 27

when we take care of our ecosystems we get

Answer 27

goods and services like sweetwater park that helps filter water or the dung beetles that help decompose the cows poop