Brainscape's Knowledge GenomeTM

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


See full index

State of the Art: Ecology > Basic terms and concepts > Flashcards

Basic terms and concepts Flashcards

1
Q

ecosystem

A

community of biotic and abiotic components which are linked by nutrient and energy cycles and interacting as a system

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

food web

A

the totality of interacting food chains in an ecosystem. It describes how the energy flows in the system

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

population

A

group of individuals of the same species, which live in the same demographic region, time and are genetically connected over generations

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

abundance

A

density of organisms per unit of area/volume

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

biomass

A

mass of organisms per unit of area/volume, includes all parts of living organisms but not dead organisms or parts thereof

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

production

A

characteristic of the community, rate of C/energy is fixed, or new biomass is built over time

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

productivity

A

characteristic of the habitat, says how great the production could be (not community or population)

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

excretion

A

the elimination of waste products produced by the metabolism (e.g. urine, faces)

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

exudation

A

diffusive excretion of small molecular compounds (e.g. amino acids, monosaccharides) by plants or phytoplankton

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

ingestion

A

uptake of material into the digestive system I= A+E

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

assimilation

A

the incorporating of nutrients into the individual; A=R+P

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

gross growth efficiency

A

relation between production and ingestion; K1=P/I

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

net growth efficiency

A

relation between production and assimilation; K2=P/A

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

efficiency of energy transfer between trophic levels

A

between 0-30%, the higher organised an organism is, the lower the TTE → lower TL – higher TTE (very generalised) 𝑇𝑇𝐸 = 𝑃𝑝𝑟𝑒𝑑𝑎𝑡𝑜𝑟/𝑃𝑝𝑟𝑒𝑦

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

efficiency of consumption and assimilation

A

assimilation efficiency AE=A/I

consumption efficiency = 𝐼𝑛/𝑃𝑛−1 (n…. trophic level)

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

necromass

A

mass of dead material that is included in the biomass (bark, hardwood…)

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

primary production (PP)

A

C fixed (photosynthetically) or new biomass built

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

secondary production

A

rate of production of heterotrophs per unit of area/volume per time (can be used for somatic growth/reproduction)

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

P:B ration

A

production per biomass: growth rate at population or community level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

autochtonous

A

materials produces within the system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

allochthonous

A

material produced outside the system and transported into it (i.e. definition depends on system boundaries)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

gross primary production

A

total C fixed via photosynthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

net primary production

A

gross primary production - losses due to respiration + exudation/excretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

gross population growth rate (µ)

A

growth of new organisms

25
Q

Which factors determine the trophic transfer efficiency how and why?

A

The higher an organism is organised, the higher are the losses due to respiration, good food quality raises the TTE, because the needed quantity shrinks

26
Q

osmotrophy

A

ability to ingest and digest dissolved material

27
Q

mixotrophy

A

ability to assimilate carbon dioxide (photosynthesis and chemosynthesis) and ingest and digest organic particles (phagotrophy) and dissolved material (osmotrophy)

28
Q

omnivory

A

ability of animals to feed on plant and animal matter

29
Q

allometry

A

body size correlates with weight specific metabolic rates (ingestion, production, respiration, excretion)

30
Q

Metabolic Theory of Ecology (MTE)

A

Very short: the metabolic rate of organism is the fundamental biological rate, which is the base for the most observed pattern in ecology

31
Q

grazing chain

A

food chain based on autotrophs (plants), herbivores and carnivores

32
Q

detritus chain

A

food chain based on detritus (dead biodegradable material) and detritivores (detritus eating bacteria and other microorganisms) and consumers

33
Q

grazing vs detritus chains in pelagic/terrestrial habitats

A
  • pelagic: grazing chain more important, because the majority of the NPP is consumed by herbivores (usually complete swallowing of the prey) – less detritus occurs
  • terrestrial: detritus chain is more important, because herbivores consume only a small part of the NPP, especially in forests, more detritus occurs
34
Q

trophic cascade (HSS)

A

A change in the production of an ecosystem trough the indirect influence of a population on a higher TL on a population of lower TL (e.g. carnivore consumes herbivores → more plant biomass can be built)

35
Q

trophic level

A

integer, says how often substance got assimilated since the last fixation by the primary production (e.g. primary producers 1, herbivores 2, first rank carnivores 3, second rank carnivores 4 etc.)

36
Q

trophic position

A

determined by the TL/TP the population is feeding on, doesn’t have to be an integer

37
Q

bottom-up-control

A

regulation of the higher TL by the lower TL (many prey → many predators, positive correlation)

38
Q

top-down-control

A

regulation of the lower TL by the higher TL (many predators → little prey, negative correlation)

39
Q

upper limit to the size ratio between predator and prey

A

max ratio terrestrial: 1000:1, pelagic: 1.000.000:1 (If the predator is getting to big, the uptake of the prey is not energetically worthwhile anymore)

40
Q

„stability” of an ecological system

A

There isn’t one definition of THE stability in ecology. There are just stability properties like persistence, resistance and resilience.

41
Q

Persistence

A

Outlast/Survival of an ecological system, e.g. preservation of the species inventory

42
Q

Resistance

A

remain essentially unchanged despite potential disorders

43
Q

Resilience

A

return to the initial state after a change due to temporary disturbances (subsumes elasticity (=speed of return to the initial state) & area of attraction (= all the states from which the initial state is reached again)

44
Q

taxonomic diversity

A

Simpson-Index 𝐷=1−Σ𝑝𝑖2𝑠𝑖=1 p…proportion of specie)
𝐷𝑚𝑎𝑥=1−𝐷𝑠 (s…specie number)
𝐸=𝐷𝐷𝑚𝑎𝑥 (E…evenness)
Simpson – relies more on evenness than specie number
Shannon-Wiener 𝐻′=−Σ(𝑝𝑖log(𝑝𝑖))𝑠𝑖=1
𝐻′=log (𝑠)
E = 𝐻′/𝐻′𝑚𝑎𝑥
SW relies more on species number than evenness

45
Q

The recycling of resources from dead org. material occurs mostly via bacteria and fungi (almost only relevant in terrestrial systems → why?!)

A

The most fungi are obligate aerobe

In terrestrial system fungi are the main decomposers of lignin, in open water ecosystems there isn’t lignin, → white rot

46
Q

define biodiversity. How is it measured?

A

Biodiversity is the variety or richness of genes, species, populations and their interactions.
You can measure it with different indices (Simpson, Shannon-Wiener etc.) to compare different ecosystems, habitats etc…

47
Q

How does biodiversity influence ecosystem functions and their spatial-temporal variability? What are the mechanisms?

A

Stability of ecosystem function increases with diversity, at first linear, then weaker → high biodiversity → low variability of ecosystem functions
The reasons are buffer mechanisms:
Compensatory mechanism between individual populations, positive covariance → less stable; negative covariance → more stable
Portfolio effect: the more individual populations the higher the probability of asynchronous fluctuations → negative covariance
Insurance Hypothesis: with high diversity the probability of an occurrence of different species with the same functions increases (negative covariance)
Facilitation: one species benefits from another
Complementarity: different niches
Jansen-Cornell effect: Probability of survival for seedlings of a plant (this hypothesis was postulated for tropic trees) increases with the distance to the next adult individual… one reason for the species richness in the tropes

48
Q

factors influencing biodiversity: latitude

A

diversity is decreasing from the tropics to the poles

49
Q

factors influencing biodiversity: extreme habitats

A

extreme habitats are low on species number, but (with enough productivity) rich in individuals and vice versa, temperate habitats are more diverse and often have fewer individuals per species

50
Q

factors influencing biodiversity: productivity

A

productivity of the habitat: unimodal curve, maximum at medium productivity, with low productivity only specialist survive, with high productivity strong competition for light → plants grow very big → fewer individuals/area, with medium productivity the diversity is the highest, because different species are limited by different resources (Tilman model)

51
Q

factors influencing biodiversity: IDH (Intermediate Disturbance Hypothesis)

A

the diversity is highest at (measured by the duration of the generation) mean interference frequency and Interference intensity; very frequently and strong disturbances → r-strategists; very seldom and weak disturbances → K-strategists; mediate frequency and intensity → both strategists are alternating, new niche dimensions arise

52
Q

factors influencing biodiversity: Temporal fluctuations

A

caused by external influences like seasons, weather, climate; or endogenous processes like predator-prey cycles; change competitive relationships, create new niche dimensions trough adaption

53
Q

factors influencing biodiversity: spatial heterogeneity

A

spatial heterogeneity and unequal access to resources: gradients in resource availability, resource concentration can differ on very small spatial scales → strong building of niches

54
Q

factors influencing biodiversity: Patchiness

A

metapopulation dynamics or source-sink-dynamics; regional coexistence, while local competitive exclusion; migration inhibits extinction

55
Q

factors influencing biodiversity: Insular biogeography

A

Insular biogeography (on near and big islands – highest diversity)

56
Q

factors influencing biodiversity: seed dormancy

A

Seed dormancy, can raise diversity, because of the outlast of bad periods, resettlement after extinction

57
Q

factors influencing biodiversity: predation

A

Predation can increase diversity (parasitism) or decrease it (predator-mediated completion, intraguild predation)

58
Q

Why do we find typically a unimodal relationship between the productivity of a habitat (e.g. determined by nutrient concentrations, precipitation) and biodiversity but a saturating function between production (of new biomass) and biodiversity?

A

Different objects: productivity (=characteristic of the habitat, says how great the production could be) and production (= characteristic of the community, rate of C/energy is fixed, or new biomass is built over time)
Different scales: In experiments we measure the production, there is a positive relationship between biomass production and diversity (complementary mechanism, dominance mechanism and facilitation → overyielding)
Observation of the productivity over different locations get averaged
Different dependency: experiments – total production depends on diversity
observations - diversity depends on abiotic factors and the competition relationships
long story short: they are different things
Unimodal relation between productivity and biodiversity because: with medium productivity the diversity is the highest, because different species are limited by different resources (e.g. Tilman model)
Saturating function between production and biodiversity because: Stability of ecosystem function increases with diversity, at first linear, then weaker → high biodiversity → low variability of ecosystem functions

State of the Art: Ecology (11 decks)

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