Community Ecology in Streams

Question 1

Draw the stream food web figure, you have to include: Watershed, DOM, CPOM, FPOM, sun, autothrops, living organic matter, collectors, shredders, scrapers and predators. Also where the allochthonous and autochthonous processes are in the food web.

Question 2

What does DOM, CPOM, and FPOM stand for?

Answer 2

○ DOM = Dissolved Organic Matter
○ CPOM = Coarse Particulate Organic Matter
○ FPOM = Fine Particulate Organic Matter

Question 3

What are autotrophs?

Answer 3

An organism that is able to form nutritional organic substances from simple inorganic substances such as carbon dioxide.

Question 4

What determines the food chain length in streams and rivers?

Answer 4

Disturbance, there is negative correlation between food chain length and high flow variation, it means the more disturbance there is the shorter the food chain.

Question 5

What determines the amount of disturbance in a stream or a river?

Answer 5

Ecosystem size, there is negative correlation between discharge variation and drainage area, this means if the ecosystem area is bigger there will be less disturbance.

Question 6

How does draught affect biota in a stream?

Answer 6

Draught affects food chain length, by shortening it.

Question 7

What does it mean when you find organisms like mayfly nymph and stonefly nymph in a stream?

Answer 7

If you find these animals in a stream, it means there is little or no pollution.

Question 8

What does it mean when you find organisms like caddis fly larva and freshwater shrimp in a stream?

Answer 8

If you find these animals in a stream, but no mayfly or stonefly nymphs, it means there is slight pollution.

Question 9

What does it mean when you find organisms like hoglouse and bloodworm in a stream?

Answer 9

If you find these animals in a stream, but no mayfly nymphs, stonefly nymphs, caddis fly larva,
and freshwater shrimp it means there is medium pollution.

Question 10

What does it mean when you find organisms like worms and rat-tailed maggot in a stream?

Answer 10

If you find these animals in a stream, but no mayfly nymphs, stonefly nymphs, caddis fly larva,
freshwater shrimp, hoglouse, and bloodworm it means there is a lot of pollution.

Question 11

Make the table of biotic integrity, with columns: group, animals, and pollution level. Groups are from A-E.