Chapter 55: Ecosystem Ecology

Question 1

Ecosystem

Answer 1

• Sum of all organisms and abiotic factors of which interact within a designated boundary

Question 2

Defining spatial boundaries of an ecosystem

Answer 2

?

Question 3

Ecosystem ecology (def.)

Answer 3

Study of energy flow and the cycling of chemicals among biotic and abiotic components in an ecosystem

Question 4

How does an ecosystem differ from a community?

Answer 4

• Ecosystem is abiotic and biotic factors

- Community is interaction between species

Question 5

Ecosystem ecologists study?

Answer 5

Transformation of energy and matter within the ecosystem

Question 6

Law of Conservation of E

Answer 6

• Energy can’t be created or destroyed (only transferred or transformed)

Question 7

Law of Conservation of Mass

Answer 7

• mass or matter = amount of an element (used for development, maintenance, or reproduction)
• Matter cannot be created or destroyed

Question 8

Laws and relation to ecosystem ecology?

Answer 8

• Energy is transformed and matter/nutrients are reused over and over (in a cycle)
• Follow where all of the energy or matter goes in an ecosystem
• Ask which organisms in the ecosystems are most important in determining where the energy and matter go

Question 9

Primary differences between mass and energy?

Answer 9

• energy is expended

- mass is recycled; cannot be created or destroyed

Question 10

Detritivores

Answer 10

Organisms that derive energy from detritus (non-living organic matter)

Question 11

Primary production

Answer 11

• Amount of light energy that is converted to chemical energy by autotrophs in given time period

Question 12

Sun’s energy as it flows into/out of an ecosystem?

Answer 12

• 10^22 joules per day
• Most hits places devoid of vegetation
• 1% of visible light that hits plant is used in photosynthesis
• Around 1/2 solar radiation absorbed in first 15 meters of water

Question 13

Gross Primary Production

Answer 13

(GPP) Total amount of light energy converted to chemical energy per unit time

Question 14

Net Primary Production

Answer 14

(NPP) Total light energy converted minus autotrophic respiration (Ra)

Question 15

New plant biomass equation

Answer 15

NPP = GPP - Ra

Question 16

Total biomass accumulation

Answer 16

NEP = GPP - Rt

Question 17

Two key factors the limit primary production in aquatic ecosystem

Answer 17

• Sunlight

- Nutrients

Question 18

Eutrophication

Answer 18

• High nutrient levels lead to overproduction of algae (chokes out O2)

Question 19

Factors limit primary production in terrestrial ecosystems at global/local scale

Answer 19

• Global: Temperature and moisture

- Local: Nutrients, light, space, herbivores

Question 20

Evapotranspiration

Answer 20

• Amount of water transpired from plants and evaporate from landscape

Question 21

Relationship between evapotranspiration and primary production

Answer 21

• Higher evapotranspiration rates associated with higher primary production

Question 22

Secondary production

Answer 22

• Amount of chemical energy in consumers’ food that is converted to own new biomass during given time period
• Not 100% efficient

Question 23

Trophic efficiency

Answer 23

• How much of production at one trophic level is transferred to the next

Question 24

Energy transfer isn’t 100% efficient because…

Answer 24

Energy is required for innumerable functions of the organism

Question 25

Factors that determine how fast detritivores decompose materials?

Answer 25

• Temperature, moisture, nutrient availabiilty

Question 26

Biogeochemical cycle

Answer 26

Route of an element or compound through an ecosystem

Question 27

Nitrogen fixation

Answer 27

Transformation of atmospheric nitrogen into NH3

Question 28

Denitrification

Answer 28

NH4+ –> NO2-

Question 29

Ecosystem ecologists study nutrient cycling how?

Answer 29

• Study cycling of key materials at small and large scales