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Flashcards in Ecosystem ecology Deck (67)
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1
Q

Who was Arthur Tansley?

A

He founded the British Ecological Society and the journal of ecology. He was the first chairman of the British Nature Conservancy

2
Q

What does ecosystem ecology look at?

A

Wind, currents, heat, geochemistry as well as communities, producers, consumers.

3
Q

What are ecosystem components?

A

Producers, consumers, decomposers, abiotic components such as water, atmosphere, soil minerals and climatic variables.

4
Q

What is the problem with global warming?

A

The distribution of temperatures will be shifted and there will be an increase in occurrence of extreme events. If there is a lot of rain there is a good chance of leaching - when water falls into the ground at once and will wash things away rather than sinking into the soil.

5
Q

Why should we care about ecosystem ecology?

A

The whole ecosystem provides us with goods and services. It provides us with a mechanistic basis for understand the Earth System.

6
Q

What are the core research areas within ecosystems?

A

Transformations of energy and matter within an ecosystem and energy budgets and factors that control energy transfer, monitoring of changes over time and space.

7
Q

What is productivity?

A

The rate of energy capture and conversion to chemical bonds.

8
Q

How much of the light is actually absorbed?

A

Only around 1% - 99% is reflected.

9
Q

What is gross primary productivity?

A

The rate at which energy is captured and assimilated by producers in an area. This includes the use of captured energy by the producers for their own metabolism via respiration.

10
Q

What is net primary productivity?

A

The rate of energy assimilated and converted to biomass by producers in an area.

11
Q

How can Net Primary Productivity be calculated?

A

GPP - respiration.

12
Q

How can primary productivity be measured?

A

The mass of producers can be measured at the beginning and end of the growing season.

13
Q

What is another way in which primary productivity can be measured?

A

Changes in CO2 uptake and release can be measured - CO2 can be measured in a light container and dark container.

14
Q

What is another way in which primary productivity can be measured?

A

Changes in O2 uptake and release.

15
Q

What is yet another way in which primary productivity can be measured?

A

You can measure from a great distance using remote sensing.

16
Q

What areas show the highest productivity?

A

Terrestrial systems and tropical rain forests.

17
Q

What areas are much lower in productivity?

A

Marine systems.

18
Q

What areas of the ocean are more productive?

A

Aquatic systems along the coasts - estuaries and coral reefs.

19
Q

What explains productivity in terrestrial ecosystems?

A

Temperature and rainfall and nutrients - nitrogen and phosphorusu can be limiting to productivity.

20
Q

What determines primary productivity in aquatic ecosystems?

A

Temperature, light and nutrients.

21
Q

What is essential for aquatic systems?

A

Light, even if the temperature is correct.

22
Q

What is consumption efficiency?

A

The proportion of net production of the lower trophic level that is consumed - amount of NPP arrives in the guts of herbivores.

23
Q

What is assimilation efficiency?

A

The percent of the consumed energy that becomes available for work or growth - the rest is lost (egested).

24
Q

What is ecological efficiency?

A

The percentage of net production from one level compared to the next lower level.

25
Q

What is the law of the 10%?

A

Every step is reducing by 10% and there is only a certain number of steps that can go up before there is no energy left behind.

26
Q

What is the problem with increasing nutrients in the ocean to try and increase productivity?

A

When you increase the amount of food in a food web, the food will end up in the consumers rather than the producers.

27
Q

What is the first law of thermodynamics?

A

Energy can be converted from one form to another but cannot be created or destroyed.

28
Q

What is the second law of thermodynamics?

A

Transformation of energy always results in some loss of dissipation of energy.

29
Q

What is the equation for consumption efficiency?

A

Consumed energy/net production of the lower trophic level.

30
Q

What is the net production efficiency?

A

The percentage of assimilated energy that is incorporated into new biomass.

31
Q

How does net production efficiency vary between highly active homeothermic animals compared to sedentary poikilothermic animals?

A

1% for active animals and up to 75% for sedentary animals.

32
Q

What is the equation for net production efficiency?

A

Net production energy/assimilated energy.

33
Q

What is the equation for ecological efficiency?

A

Net production energy of a trophic level/net production energy of a lower trophic level.

34
Q

What is the usual range for ecological efficiency?

A

2-24%.

35
Q

Why does ecological efficiency explain the number of trophic levels?

A

Plants avoid being consumed via defences which results in less energy moving up in trophic levels due to low consumption efficiency. Less transferred energy supports fewer trophic levels.

36
Q

What do aquatic ecosystems have more trophic levels?

A

Algae are consumed more efficiency.

37
Q

What is biomass residence?

A

The average time in which carbon is locked up in living biomass before it is transferred to the litter pool.

38
Q

What is standing crop?

A

The amount of biomass present at a particular time in a system.

39
Q

What food has the greatest amount of calories per acre of land, and what as the least?

A

Greatest = potato, least=beef.

40
Q

How does ecological efficiency vary for a vegetarian diet compared to a meat eating diet?

A

10% compared to 1%.

41
Q

What are the 4 major pools in ecosystems?

A

Biotic component, future use (water/soil/atmosphere), nutrients put away for a long time and temporary storage e.g. minerals in rocks.

42
Q

What is the problem with the water cycle?

A

97% of water is inaccessible as it is in the oceans.

43
Q

What are the humam impacts on the water cycle?

A

Over-abstraction from lakes and rivers, vegetation loss, soil erosion, pollution of surface water and ground aquifers, drainage of wetlands and climate impacts.

44
Q

What is the problem with global warming and the water cycle?

A

More and more evaporation will result in water not running into local areas.

45
Q

What is the problem with increasing industrialisation and the water cycle?

A

There is more water run-off and less infiltration.

46
Q

What is most of the carbon in the carbon cycle fixed by?

A

Photosynthesis and released back to the atmosphere by respiration.

47
Q

How is carbon released back into the atmosphere?

A

Respiration.

48
Q

How are humans adding CO2 into the atmosphere?

A

Burning fossil fuels, reducing photosynthetic material, farming systems.

49
Q

What is the problem with most of the nitrogen residing in the atmosphere?

A

We want it to be fixed for increased productivity.

50
Q

What are the ways in which nitrogen can be fixed?

A

Lightning fixation and bacteria fixation.

51
Q

What is the problem with eutrophication?

A

It can result in increased primary productivity but usually has negative effects such as species loss and change in community structure and toxicity.

52
Q

What is the main environmental form of phosphorus?

A

PO4.

53
Q

What are the main human impacts on the phosphorus cycle?

A

Livestock waste and phosphorus used in inorganic fertilisers that can result in eutrophication.

54
Q

What are dead zones?

A

Where phosphorus has been collecting in oceans and algal blooms form. Bacteria decomposes the algae and consumes all of the oxygen in the water.

55
Q

What are the three steps of decomposition?

A

Leaching, partitioning and micropartitioning.

56
Q

What do decomposition rates depend on?

A

Temperature, precipitation and the groups of organisms within the ecosystem.

57
Q

What does rapid decomposition result in?

A

A faster turnaround.

58
Q

What is the main disturbance in ecosystems?

A

Deforestation.

59
Q

What effect does deforestation have?

A

It significantly decreases the nutrients present and nitrate run off.

60
Q

What is another large impact on ecosystems?

A

Mining - it causes deforestation, physical damage and contamination.

61
Q

What is a natural disturbance to ecosystems?

A

Fires - they can be beneficial in germinating seeds, generating nutrients locked in biomass and the control of insect pests.

62
Q

What could increase the incident of fires?

A

Increasing temperatures, water usage, precipitation and drought due to climate change.

63
Q

How do fires affect nutrient cycling?

A

There is a loss of N and C and nutrients are transferred to ash. Warmer soil profiles alter microbial growth and decomposition rates and nutrient cycling varies depending on the time since fire disturbance.

64
Q

What is the idea of restoration ecology?

A

It seeks to initiate or speed up the recovery of degraded ecosystems using the knowledge of nutrient cycles.

65
Q

What is bioremediation?

A

Using organisms to detoxify ecosystems, such as plants, bacteria and fungi. These organisms can absorb and concentrate toxic compounds facilitating removal from the environment and can metabolise toxic molecules into inorganic or non-toxic ones.

66
Q

What is biological augmentation?

A

Using organisms to add essential materials into a degraded ecosystem such as using nitrogen fixing bacteria to increase available nitrogen in the soil.

67
Q

What is the photic zone?

A

Uppermost layer of water exposed to most sunlight.