Chapter 10

Question 1

what is decomposition?

Answer 1

Breakdown of chemical bonds
formed during the construction
of plant and animal tissue

Question 2

soils of old cemeteries have higher P content than control soil.

Answer 2

true

Question 3

what are the benefits of composting?

Answer 3

concentrates plant-available nutrients and C:N decreases

Question 4

who is a decomposer?

Answer 4

Organisms which feed on dead organic
matter

Question 5

Saprophytes/Saprophages

Answer 5

Feeding or growing upon dead
organic matter. Microbial decomposers
(bacteria, fungi, protozoa)

Question 6

Detritivores

Answer 6

An animal that feeds on
dead organic material

Question 7

Scavengers

Answer 7

Large animals that mosty
consume carcasses
of other animals

Question 8

Some plants without
chlorophyll are called
“saprophytic”.
Corallorhiza maculata
“Saprophytic” plants
actually get their energy
from saprophytic fungi
12
But they are not truly
saprophytic.

Question 9

Decomposers support diverse foodwebs.

Answer 9

true

Question 10

Centipedes are fierce predators.

Answer 10

true

Question 11

the more tree is removed, the more springtail diversity reduced

Question 12

microbial decomposers

Answer 12

Plant material, esp. wood, decomposed to a
large extent by fungi, animal material by bacteria

Question 13

Mineralization

Answer 13

Release of inorganic nutrients from organic
matter

Question 14

Immobilization

Answer 14

Incorporation of mineral nutrients into an organic
form in organisms

Question 15

what is the role of mineralization and immobilization ?

Answer 15

During decomposition, both mineralization and
immobilization happens. While decomposers set
inorganic molecules free, they also immobilize
some of them in their own body, as they grow

Question 16

both hay and straw are dead grass

Answer 16

true

Question 17

what is hay?

Answer 17

Hay is grass, legumes or other
herbaceous plants that have been
cut, dried, and stored for use as
animal fodder, particularly for
grazing livestock such as cattle,
horses, goats, and sheep. It has a
low C/N ratio, it is cut when growing

Question 18

what is straw?

Answer 18

Straw is an agricultural by-
product, the dry stalks of cereal
plants, after the grain and chaff
have been removed. It has a high
C/N ratio. it is cut after senescence

Question 19

what happens when you add straw to the field?

Answer 19

• Increased amount of micro-organisms, because
  straw is a source of energy for them
• Availability of nitrogen in soil decreases, because
  the micro-organisms immobilize it .

Question 20

how to balance mineralization and immobilization ?

Answer 20

add:
1. Undecomposed nutrient-rich organic matter
2. Composted organic matter
3. Nutrient-poor organic matter

Question 21

sockeye salmon lays egg in down stream riverbed

Answer 21

False: A female sockeye lays eggs in an
upstream riverbed. The eggs
hatch to alevins

Question 22

Alevin

Answer 22

when the egg of sockeye salmon hatches

Question 23

anadromous behaviour

Answer 23

fish live in the sea mostly,
breed in fresh water

Question 24

catadromous behaviour

Answer 24

fish live in freshwater rivers, migrate to ocean to breed.

Question 25

Nutrients released from the carcasses increase procuctivity of these nutrient-poor ecosystems. This is important for the survival of sockeye offspring

Answer 25

true

Question 26

Example of semalparous behaviour

Answer 26

Lake Huron has an introduced chinook salmon that shows similar semelparous (reproduce and die) behaviour.

Question 27

Exports out of an ecosystem

Answer 27

Gaseous, harvest, with water flow, with animal movement

Question 28

Gaseous export in the ecosystem

Answer 28

Respiration (CO2) Denitrification (NO3-→N 2) Volatilization of ammonium (NH 4+→NH 3⇡)

Question 29

export with water flow

Answer 29

litter, particles, dissolved mineral

Question 30

clearcut

Answer 30

Removal of nutrients with the harvest

Question 31

impacts of clearcut

Answer 31

Increased export of nutrients with water. More dead plant parts, and increased solar radiation → High mineralisation rates. Not enough plants there to take up the nutrients

Question 32

nitrate production is higher after clearcut.

Answer 32

true

Question 33

deadwood is an important source of forest biodiversity: less deadwood, less fungi and insects, less birds

Answer 33

true

Question 34

what is the affect of forest fires?

Answer 34

Based on its intensity: 1. volatilization of nutrients 2. increase of accessibility of nutrients for plants(P, Ca, Mg)

Question 35

Pyromineralization

Answer 35

Increased accessibility of nutrients for plants (P, Ca, Mg)

Question 36

Nutrient exports out of undisturbed ecosystems are generally low due to immobilization

Answer 36

true

Question 37

Spring ephemerals

Answer 37

reduce nutrient exports: they immobilize nutrients when mineralization increases but trees are not yet growing

Question 38

nutrient spiraling

Answer 38

On their way downstream, nutrients are repeatedly taken up by organisms and immobilized for a while. this slows down the downstream movement of nutrients.

Question 39

Coastal and equatorial upwelling brings deep, nutrient-rich waters to the surface.

Answer 39

true

Question 40

Areas of coastal and equatorial upwelling are generally highly productive ecosystems

Question 41

specific horse intestinal throughput

Answer 41

or sHIT