Prelim 3

Question 1

bio/eco centric interest in biodiversity

Answer 1

intrinsic value, consequences for sustainability of communities and ecosystems

Question 2

Anthropocentric interest in biodiversity

Answer 2

practical consequences of the loss of diversity for humans (including inspiration)

Question 3

Elton’s observation of biodiversity in communities

Answer 3

simple communities are more easily upset than richer ones

Question 4

taxonomic scales of diversity

Answer 4

• species (all are equal)
• functional groups (among species)
• phylogenetic (among species)
• genotypes (within species)

Question 5

the narrower the resource partitioning, the (……) the number of species can exist

Answer 5

greater

Question 6

mechanisms maintaining local diversity

Answer 6

• microhabitat partitioning
• food-type partitioning
• temporal partitioning

Question 7

complementarity

Answer 7

as diversity increases, there will be greater community function, often through greater resource use (at a certain point there is redundancy in function)

Question 8

ecosystem services derived from function include

Answer 8

• provision of materials
• cultural and psycho-spiritual well-being
• supporting services
• regulating services

Question 9

positive effects of diversity

Answer 9

• drought resistance
• primary production
• resistance to invasion
• crop protection

Question 10

positive effects of diversity: insurance effect

Answer 10

different species/genotypes/functional groups do better under different conditions

Question 11

positive effects of diversity: negative covariance effect

Answer 11

in stressful environments, when one does well, others suffer

Question 12

positive effects of diversity:

emergent/interaction effects

Answer 12

those benefits of diversity that cannot be predicted by species traits, but emerge from diversity per se, or interactions among the species

Question 13

disturbance

Answer 13

a relatively discrete event in time and space that changes the structure of species composition, resource availability, and the physical environment

Question 14

succession

Answer 14

a gradual change in community structure and ecosystem function over time, initiated by a disturbance

Question 15

secondary succession

Answer 15

succession after disturbance that kills most species, but leaves behind some species, propagules (seedbank), or organic matter from prior ecosystem (post fire, hurricane, ice storm, logging, agriculture)

Question 16

primary succession

Answer 16

succession on newly exposed mineral substrate, or after disturbances that remove virtually all traces of the prior ecosystem (living species and organic matter)
(lava flows, landslides, or after glacial melting)

Question 17

chronosequence

Answer 17

a group of related communities that differ in development due to differences in age (space for time substitution)

Question 18

mechanisms of succession: facilitation

Answer 18

one species helps the other species grow after a disturbance….early species pave the way for later ones

Question 19

mechanisms of succession:

inhibition

Answer 19

once a colonist becomes established, it inhibits growth of subsequent arrivals by monopolizing space/resources

Question 20

mechanisms of succession:

tolerance

Answer 20

late arriving species tolerate the presence of early species and grow despite the presence of early species because they are better competitors

Question 21

characteristics of early successional plants

Answer 21

many seeds, small seed size, low root:shoot ratio, fast growth rate, small mature size, wind seed dispersal

Question 22

characteristics of late successional plants

Answer 22

few seeds, large seed size, high root:shoot ratio, slow growth rate, large mature size, animal seed dispersal

Question 23

pioneer community/early species

Answer 23

the first community, in a successional sequence of communities, to be established following a disturbance

Question 24

climax community/late species

Answer 24

a community that occurs late in succession whose populations remain stable until disrupted by disturbance

Question 25

intermediate disturbance hypothesis

Answer 25

at low frequency of disturbance/small disturbance, species diversity is low because of competitive exclusion (K species dominate). At high frequency of disturbance/large disturbance, few taxa can tolerate environment and r species dominate. in the middle, mix of r and K and a lot of species diversity

Question 26

island biogeography: immigration rate

Answer 26

immigration rate declines as the number of species on the island approaches the number of species in the mainland species pool

Question 27

island biogeography: extinction rate

Answer 27

extinction rates increase as the number of species on the island approaches the number of species in the mainland species pool

Question 28

distance from mainland

Answer 28

as distinct from mainland increases, the equilibrium number of species on the island decreases

Question 29

island size

Answer 29

as island size increases, the equilibrium number of species increases

Question 30

immigration rates are expected to be _______for islands that are close to the mainland source pool

Answer 30

higher

Question 31

extinction rates are expected to be ______for larger islands than smaller islands

Answer 31

lower

Question 32

3 hypotheses of distributions of organisms

Answer 32

- convergence - vicariance - dispersal

Question 33

vicariance

Answer 33

splitting of one contiguous population into two or more ranges, and often results from geologic events

Question 34

latitudinal patterns of species diversity

Answer 34

species richness tends to increase towards equator

Question 35

hypothesis for latitudinal gradient: habitat diversity and area and stable climate

Answer 35

area is large and climate is stable in tropics, promoting speciation and reducing extinction

Question 36

hypothesis for latitudinal gradient: diversification rate

Answer 36

evolutionary rate (and mutation) is faster, due to higher temperatures and light effects on metabolism

Question 37

hypothesis for latitudinal gradient: diversification time

Answer 37

historically the trophic covered more of earth's surface. glaciation disproportionately impacted temperate areas. temperate species may be phylogenetically derived from tropical ancestors

Question 38

hypothesis for latitudinal gradient: productivity promotes diversity

Answer 38

productivity (production of biomass) is highest in the tropics, and this estimates energy available for the whole community

Question 39

umbrella species

Answer 39

cover ecosystems (conservation of umbrella species conserves others)

Question 40

charismatic species

Answer 40

societal attention

Question 41

8 biomes

Answer 41

desert, taiga, temperate forest, temperate grassland, tropical rain forest, tropical savanna, tropical seasonal forest, tundra

Question 42

convergent evolution

Answer 42

selective pressure of climate leading to similar evolutionary outcomes, not necessary any common taxonomic/genetic background

Question 43

pool/stock units

Answer 43

g/m^2

Question 44

flux rate

Answer 44

g m^-2 y^-1

Question 45

Gross primary production (GPP)

Answer 45

total rate of CO2 fixed into carbohydrate per unit time (total ecosystem photosynthesis)

Question 46

autotroph respiration (RA)

Answer 46

respiration by autotrophs

Question 47

net primary production (NPP)

Answer 47

net rate of organic matter fixation by autotrophs NPP=GPP-RA represents the total amount of new organic matter available for consumption by higher trophic levels

Question 48

heterotroph respiration (RH)

Answer 48

respiration by heterotrophs

Question 49

Net ecosystem production (NEP)

Answer 49

net rate of organic matter accumulation in an ecosystem NEP=NPP-RH NEP=GPP-RA-RH

Question 50

eddy covariance

Answer 50

measures fluxes of CO2 going into and out from the top of a plant canopy NEP=GPP-Re

Question 51

which biomes display the greatest NPP per unit area?

Answer 51

tropics forest, wetlands, algal bed and reef, temperate forest

Question 52

which biomes display the greatest NPP in Total earth?

Answer 52

tropical forest, open ocean, temperate forest

Question 53

terrestrial NPP increases with

Answer 53

actual evapotranspiration

Question 54

terrestrial and ocean NPP values _____

Answer 54

are similar

Question 55

where do nutrients needed for primary production come from

Answer 55

recycled within ecosystem, small part comes from atmospheric deposition and newly added via weathering

Question 56

plants limit their nutrient loss with

Answer 56

- reducing tissue turnover | - nutrient resorption--translocation

Question 57

biological N fixation

Answer 57

inputs: stable N2 gas (inorganic) outputs: organic N that can be absorbed by plants

Question 58

denitrification

Answer 58

input: NO3- (nitrate) output: N2 byproduct: N2O (greenhouse gas)

Question 59

nitrification

Answer 59

input: NH4+ (ammonium) output: NO3- (nitrate) byproduct: (NO2) bacterially driven process

Question 60

mineralization

Answer 60

- mineralization by bacteria makes N bio-available | - recycling of nitrogen always greater than rate of N fixation

Question 61

problems with N cycle

Answer 61

creation of reactive biologically available forms of nitrogen cause acidification and fertilization

Question 62

eutrophication steps

Answer 62

1) more N=greater biomass to facilitate dominant species 2) greater biomass=more dead matter 3) heterotrophic consumption is amplified, resulting in higher CO2 4) low O2 entering hypoxia, bad for animals

Question 63

phosphorus cycle

Answer 63

no gas transfers, phosphorus stays in same oxidation-reduction state