Production

Question 1

Trophic level

Answer 1

the position in food web; determined by number of energy transfers from primary producers to that level

Question 2

Primary producers

Answer 2

occupy first trophic level

Question 3

Herbivores

Answer 3

(primary consumers) occupy the second trophic level.

Question 4

Carnivores

Answer 4

(secondary consumers) occupy the third trophic level

Question 5

Carnivores that feed on carnivores

Answer 5

occupy 4+ trophic level

Question 6

primary production

Answer 6

-amount of energy fixed by autotrophs over an interval of time (measured as a rate)
-Rate at which energy from the sun used to make
sugars by plants

Question 7

Biggest source of primary production is

Answer 7

photosynthesis by plants, phytoplankton, and cyanobacteria.

Question 8

aside from photosynthesis, what else produces primary production

Answer 8

Also can occur via chemosynthesis by some species of bacteria.

Question 9

Secondary production

Answer 9

is the assimilation of organic matter by heterotrophs to produce biomass

Question 10

Plants do not produce energy for

Answer 10

the benefit of herbivores.

Question 11

Redfield Ratio

Answer 11

ratio at which elements are fixed by plants during photosynthesis

Question 12

what are the Two measures of primary production

Answer 12

Gross Primary production
Net Primary production

Question 13

Gross Primary production

Answer 13

Total amount of energy fixed by
all autotrophs in an ecosystem

Question 14

• GPP =

Answer 14

Photosynthesis

Question 15

Net Primary production

Answer 15

The total amount of energy fixed by all the autotrophs in the
ecosystem, minus the cost associated with its fixation.

Question 16

NPP =

Answer 16

Photosynthesis - Respiration

Question 17

how to know difference between GPP and NPP

Answer 17

only NPP refers to the amount of energy available to consumers in an ecosystem.

Question 18

(AR+HR)

Answer 18

Respiration

Question 19

how much fixed carbon is used for cellular respiration, and what does it support?

Answer 19

half of it.
Used to support biosynthesis and cellular maintenance

Question 20

how do plants respond to environmental conditions

Answer 20

allocating carbon to growth of different tissues

-Allocation of NPP to storage organs provides insurance against loss of tissue to herbivores, disturbances/damage such as fire or frost

Question 20

Substantial amounts of NPP (up to 20%) may be allocated to

Answer 20

defensive secondary compounds

Question 21

how is Primary Production quantied

Answer 21

NPP is estimated by measuring increase in plant
biomass in experimental plots and scaling up to the
whole ecosystem
-harvest techniques, remote sensing

Question 22

Harvest techniques

Answer 22

• Measure increase in biomass over the growing season
• Radial growth of wood must be considered
• DBH – “Diameter at breast height”

Question 23

measuring NPP belowground is

Answer 23

more difficult
-Fine roots turn over more quickly than shoots – they die and are replaced quickly so harvests must be more frequent

-Roots may exude carbon into the soil or transfer it to mycorrhizal or bacterial symbionts

Question 24

Remote sensing

Answer 24

Remote sensing quantifies wavelengths that are reflected off of the earth’s surface

Question 25

NDVI:

Answer 25

Normalized difference vegetation index
-basically assessing Chlorophyll concentrations - a
spectral signature that may be a proxy for GPP/NPP

Question 26

what is NDVI used to estimate

Answer 26

used to estimate CO2 uptake and NPP, deforestation, desertification, atmospheric pollution, and other phenomena

Question 27

NDVI of zero

Answer 27

An area with nothing growing

Question 28

NDVI values < 0

Answer 28

suggest a lack of dry land;

Question 29

The ocean will yield an NDVI of

Answer 29

-1

Question 30

NDVI of one

Answer 30

dense, healthy vegetation

Question 31

Terrestrial primary production is
generally limited by

Answer 31

by temperature
and moisture

Question 32

Highest rates of terrestrial primary productivity occur in

Answer 32

warm, moist conditions

Question 33

Actual EvapoTranspiration (AET)

Answer 33

total amount of water that evaporates and
transpires during given time period (usually a year)

Question 34

how is Primary production highly correlated with AET

Answer 34

Ecosystems with the highest AET are warm and receive
large amounts of precipitation.
* Ecosystems tend to have low levels of AET either
because they receive little precipitation, are very cold,
or both.
* Both hot deserts and cold tundra exhibit low levels
of AET.

Question 35

AET is Highly correlated with

Answer 35

annual precipitation

Question 36

NPP can be increased by adding

Answer 36

nutrients to the soil

Question 37

Liebig’s law of the minimum

Answer 37

-plant growth is not limited by the total amount of all soil nutrients available but by the soil nutrient variable that is present in the lowest quantity

Question 38

Marine NPP usually greatest near the shores of oceans, where…

Answer 38

• nutrients from terrestrial runoff arrive
• nutrients arise from disturbance of bottom sediments
• nutrient upwellings arrive from the greater water depths

Question 39

phosphorus causes

Answer 39

eutrification, increases phytoplankton population

Question 40

Marine Primary Production- where is highest primary production

Answer 40

Highest rates of primary production by marine phytoplankton are generally concentrated in areas with higher levels of nutrient availability – near shore areas.

Question 41

Dead zones

Answer 41

hypoxic areas (< 2mg/L oxygen), typically a consequence of pollution, eutrophication, and high rates of decomposition, that are essentially devoid of marine life.