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1

bio/eco centric interest in biodiversity

intrinsic value, consequences for sustainability of communities and ecosystems

2

Anthropocentric interest in biodiversity

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

3

Elton's observation of biodiversity in communities

simple communities are more easily upset than richer ones

4

taxonomic scales of diversity

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

5

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

greater

6

mechanisms maintaining local diversity

-microhabitat partitioning
-food-type partitioning
-temporal partitioning

7

complementarity

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

8

ecosystem services derived from function include

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

9

positive effects of diversity

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

10

positive effects of diversity: insurance effect

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

11

positive effects of diversity: negative covariance effect

in stressful environments, when one does well, others suffer

12

positive effects of diversity:
emergent/interaction effects

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

13

disturbance

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

14

succession

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

15

secondary succession

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)

16

primary succession

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)

17

chronosequence

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

18

mechanisms of succession: facilitation

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

19

mechanisms of succession:
inhibition

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

20

mechanisms of succession:
tolerance

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

21

characteristics of early successional plants

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

22

characteristics of late successional plants

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

23

pioneer community/early species

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

24

climax community/late species

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

25

intermediate disturbance hypothesis

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

26

island biogeography: immigration rate

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

27

island biogeography: extinction rate

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

28

distance from mainland

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

29

island size

as island size increases, the equilibrium number of species increases

30

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

higher

31

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

lower

32

3 hypotheses of distributions of organisms

-convergence
-vicariance
-dispersal

33

vicariance

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

34

latitudinal patterns of species diversity

species richness tends to increase towards equator

35

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

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

36

hypothesis for latitudinal gradient: diversification rate

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

37

hypothesis for latitudinal gradient: diversification time

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

38

hypothesis for latitudinal gradient: productivity promotes diversity

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

39

umbrella species

cover ecosystems (conservation of umbrella species conserves others)

40

charismatic species

societal attention

41

8 biomes

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

42

convergent evolution

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

43

pool/stock units

g/m^2

44

flux rate

g m^-2 y^-1

45

Gross primary production (GPP)

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

46

autotroph respiration (RA)

respiration by autotrophs

47

net primary production (NPP)

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

48

heterotroph respiration (RH)

respiration by heterotrophs

49

Net ecosystem production (NEP)

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

50

eddy covariance

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

51

which biomes display the greatest NPP per unit area?

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

52

which biomes display the greatest NPP in Total earth?

tropical forest, open ocean, temperate forest

53

terrestrial NPP increases with

actual evapotranspiration

54

terrestrial and ocean NPP values _____

are similar

55

where do nutrients needed for primary production come from

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

56

plants limit their nutrient loss with

-reducing tissue turnover
-nutrient resorption--translocation

57

biological N fixation

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

58

denitrification

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

59

nitrification

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

60

mineralization

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

61

problems with N cycle

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

62

eutrophication steps

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

63

phosphorus cycle

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