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Year 2 Ecological Systems > Lakes > Flashcards

Flashcards in Lakes Deck (66)
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1
Q

How can lakes vary?

A

Physical characteristics, chemical, ecology

2
Q

When is phosphorous considered limiting?

A

> 16:1

3
Q

What are the physical descriptors of a lake?

A

Length width breadth depth shoreline length light availability

4
Q

Name a lava dammed lake in Africa?

A

Lake Kivu

5
Q

Name a crater lake in Africa?

A

Naivasha, close to lake George

6
Q

Name a Rift Valley lake in Africa?

A

Tanganiyka, Malawi, Turkana, Edward

7
Q

Name flood plain lagoons in Africa?

A

Bangwelu, Mweru

8
Q

What is lake residence time?

A

Amount of time water stays in a lake?

9
Q

What is the equation for residence time?

A

Volume / mean rate of inflow

10
Q

What are the average wavelengths of active radiation?

A

400-700nm

11
Q

What is the worlds deepest lake?

A

Baikal, 1620m

12
Q

What are lake Baikal and Tanganyika?

A

Tectonic lakes

13
Q

What is the middle part of a Rift Valley called?

A

Horst

14
Q

What is the length and width of baikal?

A

636km by 80km

15
Q

What is the shoreline length of baikal?

A

2,100km

16
Q

What makes up baikal?

A

3 depressions, making up 20% of the worlds fresh water

17
Q

How many species of fauna and flora live around lake baikal?

A

1,200 animal species 1,000 plants

18
Q

What is a thermokarst lake?

A

Formed in tundra rapid heating then freezing, pool like

19
Q

What lakes are caused by river meanders?

A

Oxbow lakes

20
Q

How can glaciers form lakes?

A

I’ve scour creates cirque lakes, also kettle lakes

21
Q

Describe the features of a lake used for hydropower?

A

Water released periodically, widely fluctuating river flow

22
Q

Give an example of a dam used for hydropower?

A

Hoover dam

23
Q

Describe a flood storage lake?

A

Water stored during winter, released during summer, more stable flow regime

24
Q

What is a lotic body of water?

A

River

25
Q

What is a lentic system?

A

Lake, standing water

26
Q

How does velocity impact lakes?

A

Less significant than rivers

27
Q

What is depth important for in rivers?

A

Light penetration and temperature regime

28
Q

What are common in lakes over the year?

A

Seasonal patterns In temp

29
Q

What kind of production is more prevalent?

A

Autochthonous, benthic algae and macro phytes

30
Q

What is the upper warmer layer of the lake?

A

Epilimnion

31
Q

What is the lower level of the lake called?

A

Hypolimnion

32
Q

What is the separation called in the lake between the upper and lower parts of the lake?

A

Thermocline

33
Q

Why is stratification important in the lake?

A

Nutrient cycling and oxygen availability

34
Q

When does the thermocline form?

A

Summer

35
Q

Why was lake Bala grounds for research in 1997?

A

Around summer stratification caused low oxygen at the lowest part of the lake

36
Q

Which fish was endangered in Bala?

A

Gwyniad

37
Q

What are limiting factors for plants in the lake?

A

Nutrients and light

38
Q

Where does green algae production take place in the lake?

A

Top of the lake

39
Q

Where does energy loss go into the lake?

A

Heat

40
Q

Where does the major herbivore production take place?

A

Under the green algae layer, above carnivore layer

41
Q

What is turbidity?

A

Light intercepted by suspended particles

42
Q

Why would turbidity effect plankton growth?

A

Limits photosynthesis

43
Q

What influences lake colour?

A

Dissolved substances eg humic acids in peaty waters

44
Q

How can we measure light penetration?

A

Secchi disk, lower below water

45
Q

What are oilgotrophic lakes?

A

Nutrient poor, low productivity, high transparency in the epilimnon high dissolved oxygen in the hypolimnon

46
Q

What are eutrophic lakes?

A

Nutrient rich, high productivity, low transparency on the epilimnon, low dissolved oxygen

47
Q

Where does meso trophic lakes sit between oilgotrophic and eutrophic?

A

In the middle

48
Q

What are the producers in a lake?

A

Phytoplankton, littorella (shore weed), nuphar lutea

49
Q

What animals and plants does the lake support?

A

Algae, macrophytes, zooplankton, benthic invertebrates, fish, birds, mammals

50
Q

What adaptations do small invertebrates have to breathe underwater?

A

Breathing tubes

51
Q

What can small phytoplankton do?

A

Float up and down in water, but change elevation

52
Q

What is a classic lake fish?

A

Roach

53
Q

What predators can be found in lakes?

A

Perch, pike, osprey and otter

54
Q

What are the main consumers?

A

Pelagic and benthic invertebrates

55
Q

What are the smaller lake invertebrates?

A

Cladocera, phantom midge larvae

56
Q

What is a common hyaline adaptation for lake animals?

A

Very see through

57
Q

What are normally the keystone species?

A

Fish

58
Q

What is the keystone species of lake Bala?

A

Gwiniad, Lyn tegid

59
Q

What does the gwyniad eat?

A

Plankton

60
Q

Where is it common to get dominan species?

A

High latitudes or extreme conditions, one species adapts well

61
Q

What limits growth in winter?

A

Chlorophyll lack of light

62
Q

What happens to the lake in spring?

A

Plants use up all the nutrients, lots of chlorophyll

63
Q

What is euphoric depth?

A

Within which photosynthesis is possible

64
Q

What is littoral zone?

A

Lake bed where plants can grow

65
Q

What is profundal zone?

A

Lake bed where there is no plant growth

66
Q

How much light do phytoplankton need

A

At least 1%