Ch 55 Ecosystems Flashcards Preview

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Flashcards in Ch 55 Ecosystems Deck (63):
1

Ecosystem size range

Microscopic to large scale

2

Two main processes in an ecosystem:

1) Energy flow
2) Chemical cycling

3

___ flows through an ecosystem

Energy

4

___ cycles within an ecosystem

Matter

5

1st law of thermodynamics

Energy is neither created nor destroyed, but can be transformed from one form to another

6

2nd law of thermodynamics

Physical systems tend to proceed to a state of greater disorder (entropy)

7

Law of conservation of mass

States that matter can be neither created nor destroyed

8

1)___ elements are continually 2)___ within an ecosystem

1) Chemical
2) Recycled

9

What kind of system is an ecosystem?

An open system

10

Open systems absorb:

1) Energy
2) Mass

11

Open systems release:

1) Heat
2) Waste products

12

Primary production

The amount of light energy converted into chemical energy by autotrophs in a given time period

13

The extent of 1)___ ___ sets the spending limit for an 2)___ ___ ___

1) Photosynthetic production
2) Ecosystem's energy budget

14

Gross primary production (GPP)

The total primary production of an ecosystem

15

Gross primary production is measured as what?

The conversion of chemical energy from photosynthesis per unit time

16

How is net primary production (NPP) calculated?

Gross primary production (GPP) minus energy used by primary producers for respiration

17

Two ways net primary production (NPP) is expressed:

1) Energy per unit area per unit time (J/m^2*yr)
2) Biomass added per unit area per unit time (g/m^2*yr)

18

Net primary production (NPP)

The amount of new biomass added in a given time period

19

Ecosystems vary greatly in what?

Net primary production

20

Ecosystems contribute to what?

The total net primary production on Earth

21

Net ecosystem production (NEP)

The total biomass accumulated during a given period

22

How is net ecosystem production (NEP) calculated?

Gross primary production minus the total respiration of all organisms (consumer + producers) in an ecosystem

23

Net ecosystem production (NEP) is estimated by comparing what?

The net flux of CO2 and O2 in an ecosystem

24

In marine and freshwater ecosystems, what controls primary production?

1) Light
2) Nutrients

25

What two nutrients most often limit marine production?

1) Nitrogen
2) Phosphorus

26

Eutrophication

The addition of extra nutrients to bodies of water

27

Results of eutrophication:

1) Algae population explosions
2) Depletion of oxygen from these habitats

28

Critical load

The amount of added nutrients that can be absorbed by plants without damaging ecosystem integrity

29

What causes dead zones?

Decomposition of phytoplankton blooms, which create low oxygen levels

30

In terrestrial ecosystems, what affects primary production on a large scale?

1) Temperature
2) Moisture

31

In terrestrial ecosystems, what affects primary production on the small scale?

Soil nutrients (nitrogen, etc.)

32

Secondary production

The amount of chemical energy in food converted to new biomass during a given period of ime

33

Production efficiency (definition)

The fractions of energy stored in food that is not used for respiration

34

Production efficiency (equation)

Net secondary production/Assmilation of primary production

35

Do ectotherms or extotherms have higher production efficiencies?

Ectotherms

36

Trophic efficiency

The percentage of production transferred from one trophic level to the next

37

What is trophic efficiency, usually?

~10%

38

Terrestrial ecosystem biomass pyramid

inefficiency of production transfer between trophic levels leads to a pyramid in the distribution of biomass

39

In the terrestrial ecosystem biomass pyramid, is there more biomass at higher or lower levels?

Lower levels

40

In the terrestrial ecosystem biomass pyramid, 1)___ ___ ___ is required to produce biomass at 2___ ___ ___

1) More total energy
2) Higher trophic levels

41

Do terrestrial or aquatic ecosystems transfer energy more efficiently?

Aquatic ecosystems

42

Why do aquatic ecosystems transfer energy more efficiently?

1) More cold-blooded (low metabolism) consumers
2) Longer food chains
3) More rapid turnover in primary producers

43

1)___ primary production, 2)___ standing producer biomass

1) High
2) Low

44

Gaseous forms of what four elements occur in the atmosphere and cycle globally?

1) Carbon
2) Oxygen
3) Sulfur
4) Nitrogen

45

All elements cycle between 1)___ and 2)___ reservoirs

1) Organic
2) Inorganic

46

What kind of elements cycle locally?

Less mobile elements (phosphorus)

47

When are less mobile elements cycled more broadly?

When they are dissolved in aquatic systems

48

Only ___ of Earth's water is available in lakes, streams, and groundwater

1%

49

What is the main process driving the water cycle?

Evaporation by solar energy

50

Carbon cycle

Carbon added to the atmosphere is removed

51

How is carbon added to the atmosphere?

By respiration of living organisms (CO2)

52

How is carbon removed from the atmosphere?

By photosynthesis

53

Major reservoirs of carbon:

1) Soil
2) Oceans
3) Biomass
4) Atmosphere
5) Fossil fuel (oil)

54

Nitrogen cycle

Only plans and bacteria can acquire nitrogen from the atmosphere to make organic molecules from which animals can acquire nitrogen

55

Phosphorus is a major component of:

1) Nucleic acids
2) Phospholipids
3) ATP

56

What is the most important inorganic form of phosphorus?

Phosphate (PO4)

57

Major reservoirs of phosphorus:

1) Sedimentary rocks
2) Ocean
3) Organisms

58

What heavily dictates the rate at which nutrients cycle?

The rate of decomposition

59

What controls the rate of decomposition?

1) Temperature
2) Moisture
3) Nutrient availability

60

Restoration ecology

The study of ways to initiate or speed up the recovery of degraded ecosystems

61

How does restoration ecology try to restore degraded ecosystems?

Manipulating biogeomechanical signaling

62

Bioremediation

The use of organisms (bacteria, fungi, plants) to detoxify ecosystems

63

Biological augmentation

The use of organisms to add essential materials to a degraded ecosystem