Deck 26: Biomass Production

Question 1

If gross primary production is 20mg/C/ha/yr and the energy lost in plant cellular respiration is 15 mg/C/ha/yr then what is the net primary production in mg/C/ha/yr?

A) 5
B) 35
C) 0.75
D) 1.33
E) 300

Answer 1

5

Question 2

The efficiency of gross primary production is greatest in

A) Desert plants
B) Coniferous trees
C) Phytoplankton
D) Deciduous trees
E) Herbs

Answer 2

Coniferous trees

Question 3

The two most important factors limiting primary production in aquatic environments are

A) Temperature and nutrients
B) Water availability and temperature
C) Light and nutrient availability
D) Salinity and pH
E) Temperature and salinity

Answer 3

Light and nutrient availability

Question 4

Dead zones are marine areas with

A) Too low nutrients to support life
B) Too low temperature to support life
C) Too high nutrients which cause bacterial growth and oxygen depletion
D) Too high temperatures which cause bacterial growth and oxygen depletion
E) Too saline areas to support life

Question 5

Primary production consumed in an ecosystem generally increases as _________ and _________ concentrations increase.

A) Phosphorus, potassium
B) Potassium, nitrogen
C) Nitrogen, phosphorus
D) Phosphorus, calcium
E) Calcium, sodium

Question 6

In the majority of experiments, marine productivity increases most where experimenters added

A) Phosphorus
B) Silicon
C) Iron
D) Nitrogen
E) c and d

Question 7

The end result of decomposition is

A) Water and oxygen
B) Carbon dioxide and sulphur dioxide
C) Organic nutrients and water
D) Inorganic nutrients, carbon dioxide and heat
E) Water, heat and humus

Question 8

Most energy from plants goes first to

A) Herbivores
B) Carnivores
C) Decomposers
D) Other plants
E) Algae

Question 9

What is the correct order of processes in decomposition

A) Nitrification, leaching, fragmentation
B) Leaching, fragmentation, chemical attenuation
C) Detrification, leaching, humus
D) Microbial activity, chemical attenuation, assimilation
E) Defecation, earthworm activity, assimilation

Question 10

Which organisms are most active in the chemical attenuation of plant litter?

A) Earthworms
B) Small soil invertebrates
C) Moles
D) Fungi and bacteria
E) Protozoa

Question 11

Residence time of litter, or time required for litter to decompose is

A) Equivalent to the decomposition constant, k
B) 1/k
C) Litter pool/k
D) k/litter fall
E) litter fall/litter pool

Question 12

After a given time, the mass remaining of litter decreases if the lignin content is _______ and the nitrogen content is ______.

A) Low, low
B) Low, high
C) High, low
D) High, high

Question 13

When arctic foxes were introduced onto same Aleutian Islands, guano input ________ and grass cover _______.

A) Decreased, decreased
B) Decreased, increased
C) Increased, decreased
D) Increased, increased

Question 14

As measured by satellite imagery, ocean chlorophyll concentrations are greatest in the tropics.

Question 15

If aspen leaves are relatively high in nitrogen and low lignin, while beech leaves are relatively low in nitrogen and higher in tannin, beech leaves should decompose faster than aspen leaves.

Question 16

Across the globe, increasing precipitation always increases net primary productivity.

Question 17

Generally, the greater the temperature, the higher the net primary productivity.

Question 18

Net primary production is higher in tropical forests than temperate forests.

Question 19

Decomposition decreases as net primary production increases.

Question 20

During decomposition, the mass of litter remaining increases as temperature increases.

Question 21

The decomposition constant, k, can be obtained by dividing litter fall by the average size of the litter pool.

Question 22

The higher the decomposition constant, the faster the rate of decomposition.

Question 23

Animal carcasses decay at a slower rate than plant material.

Question 24

Animals respond to ecosystem nutrient availability but cannot affect it.