Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

GEOG0020: Ecological Patterns and Processes > Maintaining Diversity & Ecosystem Functions > Flashcards

Maintaining Diversity & Ecosystem Functions Flashcards

1
Q

what varies between different measures of diversity

A

scale and point of comparison

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the spatial scale of alpha diversity

A

local ecological community, kept within standard area, e.g. 1000 sq. m - 0.1 hectares

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

give an example of how beta diversity can be calculated

A

Beta diversity = 1- (alpha diversity/gamma diversity)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

issues with estimating species richness in the tropics

A

“sampling is rarely random and unbiased, so it is hard to use current samples to extrapolate

some of the most hyperdiverse estimates are based on v small sample sizes

synonym issue - species that share names or have been catalogued twice”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

species richness reading

A

Mora et al 2011, they guess 8.7m eukaryotes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the predator prey model for theorising species richness in the tropics

A

there are more taxonomists than ever before, but they’re finding the same number of species, so perhaps there aren’t many more. Estimate 2 million. Costello et al 2011

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

which approach to calculating species richness in the tropics is used by Scheffers et al 2012

A

add best estimates of each taxa, excluding very high values (over 20 million). They guess 9.6m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

given that the averaging of the 3 methods gives 8 million total species in the tropics, how many of those are known to science

A

1.6 million or 20%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

given that the averaging of the 3 methods gives 8 million total species in the tropics, how many of those are known to science
in the tropics, which factor drives the alpha diversity of trees

A

moisture availability - negative relationship w length of dry season

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

in basic terms, what are the 2 types of theories on how the tropics avoid competitive exclusion

A

either the tropics are better at creating lots of small niches or they have some mechanism to avoid competitive exclusion and allow survivorship of rare species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

give an example of niche differentiation with regards to light in tropical forests

A

light demanding pioneer species grow fast and die in the underbrush, and shade tolerant species grow slower but last longer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the intermediate disturbance hypothesis

A

“open area allows colonization by early successional species, which are slowly outcompeted by slower growing successional species.

Max diversity is in the intermediate stage, when there are bits of forest that allow both”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

reading for intermediate disturbance hypothesis

A

Molino and Sabatier 2001

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

issues with intermediate disturbance hypothesis

A

not a significant enough effect on diversity, most species in a forest are not pioneer species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

issues with soil type diversity explaining how so many species coexist

A

hundred of species live on each one of the small soil types, so they still don’t have separate soil niches from each other but can coexist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the regeneration niche idea of explaining niche differentiation

A

plants need different conditions across their life cycle, giving more opportunities for niche separation - Grubb 1977

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

issues with regeneration niche explaining niche differentiation

A

difficult to test, so no evidence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is another name for the Janzen Connell hypothesis

A

density/distance dependent mortality OR negative density dependence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is the Janzen Connell hypothesis

A

most tree seeds get dispersed near the parent tree, which then get predated on more, so the ones that survive are the few that dispersed further

20
Q

which 2 processes make up the Janzen Connell hypothesis

A

density responsive mortality and distance responsive mortality

21
Q

what is density responsive mortality

A

one of 2 processes making up the Janzen Connell hypothesis which works to stop common species becoming more common by predation occurring more near high density areas

22
Q

what is distance responsive mortality

A

one of 2 processes making up the Janzen Connell hypothesis which works to help rare species survive by having predators congregate near high density areas, avoiding further dispersed seeds

23
Q

reading for density response mortality

A

bell et al 2006

24
Q

reading for distance responsive mortality

A

comita et al 2010

25
Q

what is the dispersal recruitment limitation idea for explaining the lack of competitive exclusion in the tropics

A

since most seeds do not disperse far past their mother trees, species do not interact with each other particularly often, so no/little competition

26
Q

what are ecosystem functions

A

the products, activities, processes or properties ecosystems provide as a result of inter and intra species and environment interactions

27
Q

give examples of ecosystem functions

A

net primary productivity, nutrient cycling, decomposition of dead material, soil development

28
Q

what are ecosystem services

A

ecosystem functions that matter to people - anthropocentric

29
Q

4 types of ecosystem services

A

“supporting
provisioning
regulating
cultural”

30
Q

give examples of ecosystem services

A

security, food, shelter, climate regulation, medicine, clean water, culture, recreation

31
Q

how have ecosystem functions degraded as a result of anthropogenic influences

A

“25% non insect species threatened with extinction,
10% of insects
global wild mammal biomass has fallen by 82%
72% of indicators show ongoing deterioration of indigenous peoples nature”

32
Q

what is the biodiversity ecosystem function worldview

A

a recent understanding that life affects the conditions of life by affecting biogeochemical processes

33
Q

name the 4 potential patterns of a BEF relationship

A

“null (there is none)
rivet (we can lose a few but if we lose too many then there’s trouble)
redundancy ( if we lose some species, others step in and maintain that productivity)
idiosyncratic (no pattern, all species vary)”

34
Q

what is the biodiversity-stability relationship

A

“more species = more stable functions,

better able to cope if there are issues one year bc other species which don’t need it as much will compensate”

35
Q

what is meant by ecosystem productivity

A

biomass present in an annual system

36
Q

relationship between biodiversity and ecosystem productivity

A

strong positive relationship for a while, and then the relationship levels off

37
Q

reading for relationship between biodiversity and ecosystem productivity

A

hooper et al 2005

38
Q

which 2 mechanisms allow high biodiversity to increase ecosystem productivity

A

complementarity effects and selection effects

39
Q

what are complementarity effects

A

there are likely different niches being exploited if there are more species, allowing more of the ecosystems resources to be used

40
Q

what are selection effects

A

higher diversity areas have more species on them, so it its more likely that when sampling, a high diversity species is selected

41
Q

which 4 mechanisms allow high biodiversity to increase ecosystem function stability

A

over yielding, statistical averaging, compensatory dynamics, insurance effect

42
Q

what is over yielding in BEF stability

A

multispecies communities yield more than expected from their constituent species in monoculture

43
Q

what is the impact of statistical averaging on BEF stability

A

random variation at species level causes reduction in aggregate variability

44
Q

what is the impact of compensatory dynamics on BEF stability

A

species respond asynchronously to environmental fluctuations

45
Q

what is the impact of the insurance effect on BEF stability

A

redundant species can increase stability if they respond differently to perturbations, thus dampening extremes

46
Q

reading for BEF stability

A

Lareau and mazancourt 2013

47
Q

limitations of these BEF stability relationship mechanism theories

A

“only consider species richness, not evenness etc

studies only consider one function and one service, but in reality there are multiple and they intertwine to provide services to their populations

most experimenting is done on plants - must consider other trophic levels, and impacts of trophic cascades (what if predators are lost)

GEOG0020: Ecological Patterns and Processes (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions