Water

Question 1

List the main physical and chemical parameters that determine the water quality in a wetland:

Answer 1

Light
Temperature
Dissolved oxygen
pH
Salinity
Nutrients

Question 2

What factors of the aquatic environment reduce the depth to light penetrates into the water?

Answer 2

Dissolved particles such as tannins, silt or phytoplankton

Increasing turbidity

Question 3

What human activities are likely to cause an increase in the salinity of a water body in an area with saline ground water at depth?

Answer 3

Excessive irrigation

Removal of trees or perennial vegetation and it’s replacement with annual crops

Question 4

Why is the availability of phosphorus often of more interest than the availability of nitrogen in freshwaters subject to eutrophication?

Answer 4

Eutrophic water bodies usually have populations of N-fixing Cyanobacteria and are thus more likely to be phosphorus limited than nitrogen limited.

Question 5

What is meant by the thermal stratification of a water body and what factors might disrupt it?

Answer 5

The separation of lake water into layers of different temperatures and thus density.
Disruption is caused by wind and change of season.

Question 6

Lotic inland water:

Answer 6

Flowing water - rivers and streams

Question 7

Lentic inland waters:

Answer 7

Standing water - lakes and wetlands

Question 8

Why are macrophytes important to wetland function?

Answer 8

They photosynthesise thereby oxygenating the water during daylight hours, recycle nutrients, stabilise sediments, reduce scouring and provide habitats for aquatic organisms

Question 9

List the components of detritus-based food chain

Answer 9

Dead organic matter and faeces. Vertebrates and invertebrates that eat dead and decaying organic matter, and microbes (fungi and bacteria) that break it down.

Question 10

How do detritus-based food chains interact with other food chains to make a food web?

Answer 10

Nutrients released by the actions of fungi and bacteria are released for uptake by plants. Or animals that eat detritus being consumed by a carnivore.

Question 11

As you move from the surface waters to the boots. Of a deep lame what environmental factors will change and what Kim’s of organisms might be present?

Answer 11

Decrease in light
Change in wavelengths present
Decrease in temperature
Decrease in daily and seasonal fluctuations in temperature

Photosynthetic organisms only to the compensation depth, carnivores, detritavores and decomposes below this depth