Brainscape's Knowledge GenomeTM

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


See full index

EART25001 Ecology and conservation > Components of freshwater ecosystems > Flashcards

Components of freshwater ecosystems Flashcards

1
Q

Give four examples of services that water ecosystems provide humans

A

Transport, irrigation, hygiene, waste disposal

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

Describe lentic ecosystems

A

Stationary/slow flowing water. Closed system.

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

Name three types of water ecosystem

A

Lentic and lotic ecosystems and wetlands

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

Give three examples of lentic ecosystems

A

Lakes, ponds, and pools

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

Give three factors that can be used to classify lentic ecosystems

A

Age, size, and nutrient richness

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

Describe lotic ecosystems

A

Running water. Open systems

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

Give three examples of types of lotic ecosystems

A

Rivers, streams, and springs

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

Describe how lotic ecosystems affect water chemistry.

A

Their catchment area influences river contents. They transfer, transport, and dilute materials and chemicals.

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

Describe wetlands

A

Areas of standing water that support aquatic plants. The interface of terrestrial and aquatic ecosystems. Can be permanent or temporary, natural or artificial, and flowing or stagnant.

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

How do wetlands alter stream hydrology?

A

They impede flow and enhance sediment deposition.

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

Give three examples of wetland ecosystems

A

Marshes, swamps, bogs

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

How do wetlands contribute to the release of detritus downstream?

A

They transform inflowing nutrients into organic forms

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

Define epibenthic

A

Attached or clinging to plants

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

Define neuston

A

Resting or swimming on the surface

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

Define epipelic biofilms

A

A biological complex of autotrophs and heterotrophs

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

What are benthic macroinvertebrates?

A

Organisms that inhabit the substrate for at least part of their lifecycle.

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

What size mesh can benthic macroinvertebrates be caught in?

A

200-500μm

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

What role do benthic macroinvertebrates play in freshwater ecosystems?

A

Key components of aquatic food webs (linking organic matter and nutrient resources)

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

Describe zooplankton

A

Minute aquatic animals that either drift or are very week swimmers.

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

Give three types of zooplankton

A

Rotifers, Cladocerans, and Copepods

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

What type of organism is useful in the detection of changes in the environment and why?

A

Zooplankton because they are very sensitive.

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

Give three categories of plants found in freshwater ecosystems

A

Phytoplankton, periphyton, and macrophytes

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

Describe the environment where phytoplankton are found

A

Slow-flowing rivers with high temperatures and light intensity

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

What are periphyton?

A

Unicellular and filamentous algae.

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

Where can periphyton be found?

A

Living on the substrate or on larger plants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What can macrophytes be used for?

A

Pollution indication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the four types of macrophytes?

A

Emergent leaves, floating leaved, free floating, and submerged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What types of organisms make up the major biological communities in lake and pond ecosystems?

A

Plankton and nekton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What types of organisms make up the major biological communities in floodplain and permanent wetlands?

A

Plankton, nekton, epiphyton, benthos

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What type of organisms make up the major biological communities in rivers and streams?

A

Benthos

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What types of organisms make up the major biological communities in estuaries (mudflats)?

A

Epipelic biofilms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What types of organisms make up the major biological communities in estuaries (outflow)?

A

Plankton, nekton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What can be influenced by the physical and chemical properties of freshwater ecosystems?

A

Abundance, distribution, and biodiversity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Describe the three layers of water depth

A

Epilimnion (surface, warmer), metalimnion (thermocline), hypolimnion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

How does water flow and how is the flow measured?

A

Flows in an open channel and is measure in discharge (volume of water passing through a given point per unit time)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

How does the velocity of flow in a river relate to depth?

A

Inverse proportionality

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What can flow also be influenced by?

A

The type of sediment bed, seasonal precipitation, catchment geology, bed slope, floods, human impacts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What kind of flow picks up more silty and sandy substratum?

A

Rapid river flows

38
Q

What type of substrate has a greater range of invertebrates than silt-rich pools?

A

Stony substrate

39
Q

What reduces an organism’s habitation and how?

A

Silt deposition alters an organisms’ habitation because it alters water movement and reduces oxygen levels and food availability

40
Q

What scale is used to classify rock particle sizes?

A

Wentworth Scale

41
Q

What is the effect of low water velocity?

A

Net deposition, forming a deposition zone

42
Q

What is the effect of high water velocity?

A

Net resuspension, forming an erosional zone

43
Q

Why are some organisms able to sit on top of the water’s surface?

A

The water has high surface tension (7n28Nm^-1) and the organisms attach with the least surface area possible

44
Q

What is primary production rate influenced by?

A

Light availability

45
Q

What tool is used to measure transparency in lentic ecosystems?

A

Secchi disc

46
Q

What are the respective names for the depths of water that are penetrated and unpenetrated by light?

A

Photic and aphotic zones

47
Q

What is conductivity the result of?

A

The concentration of ions

48
Q

How much more conductive is seawater than freshwater?

A

20% higher

49
Q

What is the conductivity of freshwater?

A

150-500µSeimens cm^-1

50
Q

What does high specific heat capacity and poor thermal conductivity result in?

A

Moderate diurnal and seasonal changes in water temperature and a decrease in the rate of decomposition of matter

51
Q

How does an increase in discharge affect conductivity?

A

Decreases conductivity by dilution by precipitation. Precipitation doesn’t pass through the geology, therefore does not pick up an ions.

52
Q

When is dissolved oxygen especially limiting to sensitive biota?

A

At high temperatures

53
Q

Give two reasons for low levels of dissolved oxygen in water?

A

Can be limited in stratified water due to lack of transfer to lower layers and can be depleted at night due to plant respiration.

54
Q

How does temperature affect levels of dissolved oxygen?

A

Higher temperatures result in low levels of dissolved oxygen.

55
Q

How do organisms the prefer lower levels of oxygen have an advantage over those that need more?

A

They can produce with lower oxygen availability

56
Q

What ions result in water ‘hardness’?

A

Ca2+ and Mg2+

57
Q

What ions result in permanent water ‘hardness’?

A

Cl- and CO4 2-

58
Q

What is the pH of hard water?

A

pH>8.5

59
Q

Give two examples of factors that impact water pH levels

A

Soil geology and human activity

60
Q

Give three examples of human activity that can influence water pH

A

Cement and steel industries, potassium ion fertilisers, and sodium ion wastewater

61
Q

What is the pH of freshwater?

A

Ideally pH 4.5-10.0 but generally pH 6.5-8.5

62
Q

Give two examples of processes that can lower water pH

A

Acid mine drainage and acid runoff (which can be increased by sphagnum mosses in wet swamps and peaty areas)

63
Q

Describe particulate organic matter (POM)

A

0.2µm-1mm, allochthonous organic matter

64
Q

What is the size of coarse particulate organic matter? Give four examples of CPOM

A

> 1mm. Includes living and dead planktonic organisms, leaf litter, twigs, and fruits

65
Q

What is the size of fine particulate organic matter (FPOM)?

A

0.2µm-1mm

66
Q

What size is dissolved organic matter (DOM)?

A

<0.45µm

67
Q

Give four examples of types of DOMs?

A

Anions, cations, viruses, and fine organic debris

68
Q

What material makes up major components of CPOM, FPOM, and DOM?

A

Microorganisms

69
Q

Define allochthonous organic matter

A

External materials

70
Q

Define autochthonous organic matter and give three examples

A

Indigenous plant material. Includes; periphyton, plankton, and macrophytic detritus

71
Q

Give five examples of micronutrients

A

Na, Mg, Si, K, Ca

72
Q

Give six examples of macronutrients

A

C, H, O, N, P, S

73
Q

What are C, H, O, and S usually available for?

A

Growth

74
Q

What is the ideal N:P concentration ratio in freshwater?

A

7:1

75
Q

What is nitrogen used for by organisms?

A

Amino and nucleic acids

76
Q

Define heterocyst

A

Differentiated cyanobacteria that carries out N fixing

77
Q

Give seven examples of allochthonous nitrogen loading processes

A

Rainfall, aerial deposition, dust particles, fertiliser application, fossil fuel combustion, N-fixing crops, and waste water disposal

78
Q

Give two examples of autochthonous nitrogen and phosphorus loading processes

A

Sediment and nutrient cycling

79
Q

Why can’t atmospheric nitrogen be used by organisms?

A

It is unreactive because of its stable covalent bond

80
Q

What nitrogens are most and least abundant in freshwater?

A

Nitrate (NO3) is most oxidised by lake and most abundant, nitrite (NO2) is present in small amounts

81
Q

What type of nitrogen do plant cells use and how is it transferred?

A

They use a reduced form and it is transferred intercellularly as the amino group NH2.

82
Q

What does an increase in reactive nitrogen result in?

A

Higher productivity

83
Q

What does a shortage of nitrogen for terrestrial plants suggest?

A

A shortage of nitrogen available for growth in the water

84
Q

Give three examples of where phosphorus is used in organism growth

A

Nucleic acids, organelle walls, and energy molecules

85
Q

What is the relationship between phosphorus and organism growth?

A

It is a growth-limiting nutrient

86
Q

Where is phosphorus not found?

A

In the atmosphere

87
Q

Give three examples of allochthonous phosphorus loading processes

A

Weathering of rocks, human activity (inc. detergent pollution, agricultural runoff, runoff from cities (sewage)), and detritus (POM)

88
Q

Describe the process of eutrophication

A

Phosphorus is transferred into lakes and it sinks into the sediment. Movement of P from the sediment to the water is mechanical (bioturbation)

89
Q

Where is excess phosphorus stored?

A

In algae that later sinks to the substrate

90
Q

What causes a species shift and how can this challenge the biota?

A

Can be caused by increased levels of N and P. New, harmful algae can release toxins, leading to a loss or reduction of aquatic life

91
Q

What causes increased productivity and how can this challenge the biota?

A

Can be caused by increased levels of N and P. Increased organic matter, which increases respiration, decreasing oxygen availability, leading to a loss or reduction of aquatic life.

92
Q

A 2013 paper on the consequences of the human modification of the global nitrogen cycle showed what benefits?

A

Reactive nitrogen emission lead to coastal and terrestrial eutrophication.

93
Q

A 2013 paper on the consequences of the human modification of the global nitrogen cycle showed what negative consequences?

A

Freshwater pollution and biodiversity loss. O3 and PM increase in atmosphere.

EART25001 Ecology and conservation (18 decks)

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