Lecture 2; River Continuum Concept (RCC) and Nutrient Spiralling

Question 1

name order of hierarchical scale

Answer 1

stream, segment, reach, pool/riffle, microhabitat

Question 2

different flow types

Answer 2

pools, riffles, gliddes

Question 3

how have we made it a one way flow?

Answer 3

urbanising and channelling rivers

Question 4

instars are…

Answer 4

different growth stages when the insect sheds its exoskeleton and grows a new one

Question 5

name for insects which undergo incomplete metamorphisis stage, series of instars to become an adult?

Answer 5

Hemimetabolous

Question 6

name for insects which undergo complete metamorphisis and become larvae/pupae

Answer 6

Holometabolous

Question 7

4 functional feeding groups

Answer 7

shredders
collectors (gatherers and filterers)
sracpers
predators

Question 8

role of shredders?

Answer 8

utilize CPOM and produce FPOM in this process

Question 9

role of collectors gatherers?

Answer 9

collect organic matter form the bed of river

Question 10

Role of collector flterers?

Answer 10

filter FPOM from water column, spin silk and build nets between rocks to filter FPOM

Question 11

Role of scrapers?

Answer 11

scrape diatoms and attached algae form the surface of stones and rocks

Question 12

Role of predators?

Answer 12

eat other 3 types of invertebrates

Question 13

4 stages of decay of leaves in streams?

Answer 13

1. leaching
2. conidiotniing
3. Invertebrate shredding
4. Physical abrasion

Question 14

which decay phase takes 30 days?

Answer 14

conditoning

Question 15

what attracts shredders to leaves?

Answer 15

bacteria and funghi

Question 16

when was RCC introduced?

Answer 16

1980

Question 17

what does RCC explain?

Answer 17

communities and different reaches of the rier develop different strategies wot use carbon/energy inputs and minimise carbon loss

Question 18

what is stream order?

Answer 18

a way to classify streams by size in relation to whats going on

Question 19

what is a first order stream?

Answer 19

a stream which flows directly from any source

Question 20

How is a second order stream made?

Answer 20

when 2 first order streams meet,

Question 21

how is third order stream made?

Answer 21

by 2 second order streams meeting

Question 22

3 different sectiosn of the RCC

Answer 22

• headwaters
• middle reaches
• lower reaches

Question 23

name the functional groups which dominate headwaters?

Answer 23

shredders and collectors

Question 24

functional groups which dominate middle reaches?

Answer 24

collectors and scrapers

Question 25

functional groups which dominate lower reaches/larger rivers?

Answer 25

collectors and predators

Question 26

where is P/R LOWER than 1?

Answer 26

headwaters and lower reaches

Question 27

where is P/R GREATER than 1?

Answer 27

middle reaches

Question 28

what conditions do collectors favour?

Answer 28

- available FPOM for them to feed on

Question 29

what conditions do shredders favour?

Answer 29

- high amount of leaf retention

Question 30

what conditions do predators favour?

Answer 30

- higher order streams, larger

Question 31

when is a stream considered heterotrophic?

Answer 31

- where p/R < 1 | - limited light penetration

Question 32

What is DIC?

Answer 32

- dissolved inorganic carbon | - consists of co2, bicarbonate and carbonate

Question 33

What is DOC?

Answer 33

Dissolved organic carbon | - organic material that can pass thorugh a filter (<0.7um)

Question 34

what is PIC/POC?

Answer 34

Particulate organic/inorganic carbon | - cant pass through a filter

Question 35

how is FPOM produced in the stream?

Answer 35

- DOM gets shredded and becomes FPOM used by collectors | - autotrophs used by scrapers produce FPOM

Question 36

name 3 nutrients which are limiting to productivity

Answer 36

- C, P, N

Question 37

What are the different relative %s of inorganic and organic carbon in the stream?

Answer 37

- 90% travel downstream inorganic | - 10% as organic

Question 38

uptake length?

Answer 38

average distance travelled by a nutrient molecule in inorganic form before removal from the water column

Question 39

spiral length =

Answer 39

uptake length (inorganic) + turnover length (organic)

Question 40

geomorphic factors influencing nutrient uptake?

Answer 40

- physical properties of channel | - dictates residence time of water within reach

Question 41

geomorphic retention of nutrients depends on...

Answer 41

-hydrology - size of particle - heterogeneity of stream bed LWD