Lab 7: Biomass and Energy Flow in Saskatchewan Prairies

Question 1

What did the Matador Project explore?

Answer 1

Was an extensive investigation of a mid (mixed) grass prairie on which Northern wheat-grass and smiths wheat-grass were the dominant species.

Question 2

Fresh mulch is

Answer 2

dead standing material which grew in the current or late in the previous growing season and is easily removed from the standing crop by raking gently.

Question 3

Standing crop is

Answer 3

photosynthetically active material which is clipped at ground level.

Question 4

Shoot Standing crop is

Answer 4

Combining fresh mulch and standing crop fractions yeld shoot standing crop.

Question 5

Litter is

Answer 5

the third fraction, covers the surface of the mineral soil as a layer of fine, fibrous organic material which may be several centimeter thick in areas with low fire incident.

Question 6

Biomass:

Answer 6

weight of biological system. Can be used to describe anything of organic material.

Question 7

Increase standing crop and decrease litter happens in what types of years?

Answer 7

wet year

Question 8

Decrease in standing crop and increase in litter happens in what type of years?

Answer 8

Dry year

Question 9

Why is more energy put into root production?

Answer 9

Because water is the limiting factor therefore put energy into roots to get most water.

Question 10

what is the first principle from the 5 principals?

Answer 10

1 gm of dry organic matter=4 KCals=17kj (this is low because dead organic matter-mulch and litter- is less energetic than live.)

Question 11

second principal?

NPP of shoots=

Answer 11

Net Primary Production of Shoots= 1.2 X shoot standing crop

Question 12

Third principal?

NPP of roots=

Answer 12

Net Primary Production of Roots= 1.33 X Shoot NPP

Question 13

Fourth Principal?

Underground Biomass=

Answer 13

Underground Biomass= 4X Total above ground Biomass

Question 14

Fifth Principal?
Live Shoot Standing Crop=
Dead shoot standing crop=

Answer 14

Live shoot standing crop = 1/6 of shoot standing crop

dead shoot standing crop=5/6 of shoot standing crop

Question 15

There is more underground biomass than above ground biomass because:

Answer 15

1. ) Put more energy into roots
2. ) Roots are longer lived
3. ) Rate of breakdown is slower underground

Question 16

Why is rate underground for breakdown slower?

Answer 16

1. ) Temperature (colder underground therefore slower rate of breakdown)
2. ) Oxygen (need to bind organic material too)
3. ) Moisture
4. ) Inhibitory compounds (acids, basses, Na, Sugars)(most of our soils are basic so not much opportunity for breakdown)
5. ) Mechanical break down (surface area)

Question 17

what is an ideal environment for decomposition?

Answer 17

Warm and wet and O2 rich.

Question 18

Why do fungi grow around roots?

Answer 18

Because roots leak protein and lipids that’s why!

Question 19

Mean residence time=

Answer 19

1/TR (Turnover Rate)

Question 20

Shoots Turnover Rate as %=

Answer 20

NPP shoots/ Total aboveground biomass

Question 21

Roots annual turnover rate as %

Answer 21

NPP roots/ Total belowground biomass

Question 22

%error=

Answer 22

($observed-actual$)/actual X100