Weeks 11-12

Question 1

what defines a community

Answer 1

all species that occupy the same habitat at the same time

Question 2

what defines an ecosystem

Answer 2

the organisms + the abiotic factors

Question 3

what is the most important reason as to why species are found in some areas an not others

Answer 3

dispersial - if it cant go there it cant grow there

Question 4

what are the ecological filters

Answer 4

-dispersal - disperse to certain area
-environmental (abiotic) - is the species able to grow in the environment
-interaction (biotic) - will species survive interactions with other organisms

Question 5

why isnt speciation important for determining species diversity on a local scale

Answer 5

it happens over a much larger area so it wont work on a local scale

Question 6

how do species co-exist in a community

Answer 6

they occupy diff niches/have diff roles (resource partitioning/niche differentiation)

Question 7

TF a species niche can be defined by both abiotic and biotic factors

Answer 7

T ex) temp it thrives in, food it eats, space it occupies

Question 8

how are niches affected by other species

Answer 8

the niche can either increase or decrease based on the type of interaction

Question 9

what is a fundamental niche

Answer 9

the space and resources a species uses when not interaction with other species (the maximum range)

Question 10

2 species w similar niches will

Answer 10

slightly shift away from eachother for less competition

Question 11

TF 2 species with a very similar niche will coexist and fight for it

Answer 11

F, if the niche is too similar - they are not likely to coexist

Question 12

what can help the number of species living in an area besides resource partitioning

Answer 12

moderate natural disturbances (help species to not out compete one another)
- fire
- grazing
- predation
- flooding

Question 13

what is a keystone species

Answer 13

A species that has a large effect on an ecosystem e.g. maintains biodiversity and balance, but that is NOT the dominant species

Question 14

what is it called when 2 species benefit from eachother

Answer 14

mutualism

Question 15

what is it called when one species benefits while the other is being harmed

Answer 15

parasitism

Question 16

what is it called when 2 species only do harm to eachother

Answer 16

Competition

Question 17

what factors determine biodiversity at the local scale

Answer 17

disturbances
immigration
diversity and resources
available niches

Question 18

what defines a mass extinction

Answer 18

over 75% of species gone within 2 mil yrs

Question 19

what are some factors that could have led to mass extinctions

Answer 19

volcanic eruption
ocean acidification
asteroid impacts
increased Oxygen

Question 20

what happened in the first extinction (ordovician-sulurion)

Answer 20

ordovician-sulurion extinction
- wiped out many marine invertebrates
- benefitted early vertebrates

Question 21

what happened in the 2nd extinction(devonian)

Answer 21

devonian extinction
- wiped out many ancient fish species
- benefitted early land vertebrates and seed plants

Question 22

what happened in the 3rd extinction (permian-triassic)

Answer 22

permian-triassic extincion
- wiped out many marine vertebrates, amphibians, and proto mammals
- benefitted dinosaurs

Question 23

what happened in the 4th extinction(cretaceous-paleogene)

Answer 23

cretaceous-paleogene extinction
- wiped out all non-avian dinos
- benefitted small mammals, birds, flowering plants

Question 24

what are the biggest world threats to biodiversity

Answer 24

changes in land and sea use
species overexploitation
invasive species and disease
pollution
climate change

Question 25

what type of human activities lead to habitat fragmentation/ degradation/ loss

Answer 25

- intense agriculture (urban areas) - resource extraction (logginh/mining)

Question 26

which factors determine how fragmentation affect wildlife

Answer 26

species size and shape of fragments number of fragments distance between fragments characteristics of the matrix connectivity of fragments

Question 27

whats the difference between habitat: loss - fragmentation and degradation

Answer 27

loss = cannot support population degradation = cant support lrg populations fragmentation = might support populations

Question 28

TF for some species, habitat fragmentation = habitat loss

Answer 28

T

Question 29

TF priority species are less affected by fragmentation

Answer 29

F, more affected

Question 30

how else does fragmentation affect species

Answer 30

some species need to travel long distances for food/ mate and can get blocked by a highway or river etc

Question 31

what is the edge effect of a fragmented habitat

Answer 31

When a large habitat is fragmented (broken into smaller pieces), the amount of edge area increases compared to the interior - the edge environment is different from the interior (core), more edges = less safe space for the species that want the deep undisturbed habitat

Question 32

TF more edge effect = more core habitat

Answer 32

F, less core habitat

Question 33

what are some abiotic factors of the edge effect

Answer 33

more sun more light dryer soil more wind inc temp

Question 34

what are some biotic factors of edge effects

Answer 34

altered species altered plant dispersial increased invasive plants more competiton/predation

Question 35

why cant habitat fragmentations support high biodiversity or lrg populations

Answer 35

Not enough niches or resources

Question 36

what is the extinction vortex

Answer 36

the cumulative effect of many different factors leads to a smaller and smaller population.

Question 37

TF some keystone species are the top predators

Answer 37

T

Question 38

what are ecosystem engineers

Answer 38

a type of keystone species that physically modify, create, or maintain habitats, shaping the environment in ways that benefit many other organisms

Question 39

what is an invasive species

Answer 39

- species that disrupts an ecosystem - they displace or prey excessivly - grow/spread quickly

Question 40

what makes an introduced species invasive

Answer 40

quickly reproduce dont have natural predator exploit/overtake open niche

Question 41

what are 3 types of keystone species

Answer 41

Predators ecosystem engineers mutualists

Question 42

what is a mutualist keystone species

Answer 42

form important relationships, pollinators

Question 43

what is the #1 most likely consequence of climate change

Answer 43

species shifting (moving locations) - have more predators, more comp, and more niche issues

Question 44

ecosystem stability comes from what 2 components

Answer 44

- resistance (ability to remain enchanged) - resilience (ability to recover from disturbance)

Question 45

what are foundation species (alongside keystone species)

Answer 45

build up the structure of an ecosystem and provide habitats

Question 46

Why is a diverse community/ecosystem more productive ?

Answer 46

-Can effectively utilize many different resources (less competition) * Are more resistant to disturbances * Recovers quicker from disturbances * Can consistently produce high amounts of biomass over time.