module 5

Question 1

what is ecosystem ecology?

Answer 1

studies the link between organisms and their physical environment within an each system context

Question 2

what are ecosystem processes?

Answer 2

the transfers of energy and materials from one pool to another.

Question 3

what is a pool?

Answer 3

the different compartments or reservoirs within an ecosystem.

Question 4

what is a stock?

Answer 4

the quantity of material held in a pool.

measured in units of mass per unit area.

Question 5

state factors

Answer 5

influence ecosystem processes but they are external to the ecosystem (e.g. climate and topography)

Question 6

interactive controls

Answer 6

both control and respond to ecosystem properties (e.g. resources and disturbance regime)

Question 7

carbon cycle is relatively (…..) - inputs and outputs to the ecosystem are (…..)

Answer 7

1. open
2. large

Question 8

phosphorous cycle is relatively (…..) - inputs and outputs to the ecosystem are (…..)

Answer 8

1. closed
2. small

Question 9

gross primary production

Answer 9

photosynthesis at the scale of the ecosystem.

Question 10

how is carbon lost to the environment?

Answer 10

1. respiration by plants and animals
2. combustion (burning)

Question 11

net primary productivity (NPP)

Answer 11

the carbon a plant has left to allocate to growth after losses trough respiration.

Question 12

net ecosystem productivity

Answer 12

NPP - respiration

(how much carbon accumulates in the ecosystem)

Question 13

what % imbalance of carbon is there globally?

Answer 13

6%

Question 14

what are the two main direct controls on GPP?

Answer 14

leaf area (area for light capture)

growing season length (time for light capture)

Question 15

dominance hypothesis or ‘mass ratio effects’

Answer 15

the effect of each species is additive, and proportional to it’s abundance. the dominant species have the most impact

Question 16

nich complementary hypothesis

Answer 16

the presence of a diversity of species traits, is important in determining ecosystem processes

Question 17

heterotrophs

Answer 17

organisms that rely on external sources of organic material for energy and growth

Question 18

autotrophs

Answer 18

organisms that make their own food.

Question 19

saprotrophs

Answer 19

heterotrophs that feed on detritus (dead things)

Question 20

decomposition

Answer 20

chemical and physical breakdown of detritus which ultimately releases CO2 to the atmosphere, as well as inorganic nutrients

Question 21

detritivores

Answer 21

consume detritus and chemically alter the material inside their bodies

Question 22

decomposers

Answer 22

produce enzymes that degrade detritus or soil organic matter outside the cell

Question 23

microflora and microfauna responsible for decomposition

Answer 23

Nematoda

fungi

protozoa

rotifera

Question 24

mesofauna responsible for decomposition

Answer 24

acari

collembola

Question 25

labile

Answer 25

simple chemical constituents - easier to break down

Question 26

recalcitrant

Answer 26

larger more complex molecules - harder to break down

Question 27

arbuscular mycorrhiza (AM)

Answer 27

fungi form within root cortical cells not decomposers

Question 28

ericoid mycorrhiza (ERM)

Answer 28

fungi form within root epidermal cells. single hypha heathland ecosystems

Question 29

ectomycorrhiza (ECM)

Answer 29

fungi form in between root cells. large hyphae network. can also form rhizomorphs (fungal cords) woody species

Question 30

what is a useful way of measuring activity of decomposition?

Answer 30

measuring CO2 production.

Question 31

how does temperature impact decomposition rates

Answer 31

heat soil up - it will produce more CO2. heat it up - moisture content of soil changes and influences decomposition rate.

Question 32

how does substrate quality and quantity impact decomposition rate.

Answer 32

litter with lots of labile constituents will decompose faster

Question 33

stoichiometric constraints

Answer 33

the carbon to nitrogen ratio in plants is the best predictor of how fast it will decompose. what ratio do these decomposers need to grow and are they available? = stoichiometric constraints

Question 34

home field advantage

Answer 34

things will decompose more quickly in their home environment because the microbial community is better adapted to decomposing that kind of litter.

Question 35

rhizosphere priming

Answer 35

plants growing in the soil can impact the microbial community activity and thus the rate of decomposition.

Question 36

predator

Answer 36

any organism that consumes all or part of another organism - benefitting itself.

Question 37

what are the 4 types of predators?

Answer 37

true predators - kill and eat the whole prey grazers - consume only part of the organism parasites - consume only part but live on or in the host. parasitoids - lay eggs in or on the host.

Question 38

two types of parasites

Answer 38

MACROPARASITES - grow but do not replicate in/on the host MICROPARASITES - replicate inside the host

Question 39

what is a pest

Answer 39

insect or small animal that causes destruction. usually herbivores.

Question 40

how does defence come as a cost?

Answer 40

energy used on defence cannot be used on growth and reproduction.

Question 41

how does outbreak of autumnal and winter moth cause defoliation in forest canopy?

Answer 41

pupae in soil, females emerge and lay their eggs on the tree trunk. caterpillars that emerge from these eggs eat the leaves in the summer time.

Question 42

top down control in forests.

Answer 42

app is being impacted by species at a higher trophic level.

Question 43

how do trees recover after being attacked by moths?

Answer 43

when moths dies they produce a pulse of nutrients available for the tree to grow.

Question 44

what does a mountain pine beetle do to pine trees?

Answer 44

first beetle to arrive at a pine tree releases pheromones for many more beetles to arrive. they bore into the tree and break the phloem connection between the roots and leaves. no photosynthetic transport to root. no root uptake = tissue death - tree dies.