Aniotic Factors In River Catchments

Question 1

Flow patterns

Answer 1

Flow patterns vary depending on the width and length of the river and the levels of water

Question 2

Characteristics of rivers

Answer 2

Rivers order >6
Rapid currents
Deep waters
Muddy sediments
Primary production plays major role

Question 3

Talk about flow in rivers

Answer 3

Current velocity is a direct physical force that organisms experience in the water and at the substrate level.

Question 4

Riffles are

Answer 4

Shallow with turbulent waters passing through and over gravel = biota get enough DO and protection.

Question 5

Deep pools..

Answer 5

Have slow moving water = accumulation of decaying terrestrial debris (CPOM)

Question 6

Organisms need place to hide

Answer 6

Réfugia are extensions on to flood plains furring flooding.
Dead zones/ slow flow
For most macroinvertebrates this réfugia is called the hypothetical zone.

Question 7

Flow discharge has what affects on macroinvertebrates

Answer 7

Indirect
Delivery of food particles (nutrients/dissolved gases influencing growth)

Direct
Eroded from a substrate
Energy reserves depleted - work to maintain position on water.

Question 8

What are the ecological processes affected by flow

Answer 8

Dispersal
Delivery of nutrient & gases
Predator prey interactions
Habitat use
Competition

All these affect benthic organisms