Wetland Soils Review Questions for Exam 1:

1) Are wetland soils dominated by organic or mineral soil particles? What is a typical range of organic matter content in wetland soils?

2) Define soil texture, structure, and porosity, and show how they are interrelated.

3) Demonstrate the effects of an elimination of gaseous Oxygen in the soil atmosphere. What chemical reactions will it affect?

4) Demonstrate with figures how rock strata or soil properties may move water laterally by gravitational forces. What is the significance of such changes in water movement?

5) Describe properties of organic matter, its nature and function in soil.

6) Draw a typical soil profile that includes at least 4 horizons, label the horizons, and describe some of the characteristics of the horizons of your soil.

7) Explain capillarity and why soils exhibit it.

8) In which direction does soil capillarity cause water to flow? Demonstrate with a figure.

9) Explain the nature of dissolution using an ionic solid as an example. Write a chemical formula demonstrating a dissolution reaction. Give a similar example of precipitation.

10) Give 3 potential sources for net charge in soil. Explain how each functions.

11) How does a soils pore space differ from aeration? Compare and contrast definitions for the two.

12) How does soil structure affect the water holding capacity of a soil?

13) How will pH affect the availability of soil nutrients? Give examples.

14) How would soil swelling affect the flow of water and the potential for formation of a wetland soil? Show with pictures.

15) How would traffic across a soil affect its physical properties?

16) In what directions does water typically flow out of a soil? How can water movement be blocked to form a wet soil where one would otherwise not exist?

17) Two characteristics define the aeration of a soil. What are they?

18) Under aerobic conditions, what is the primary electron acceptor for oxidation of organic matter in soil? What are the alternate electron acceptors what oxygen is depleted.

19) What are the names that we give soil organisms that can use the following electron acceptors? 1) respire with gaseous oxygen only, 2) respire without gaseous oxygen only, 3) respire with either

20) What are the size distributions for sand, silt, and clay? What is the texture of a soil that is 30% sand and 20% clay? What is its structure?

21) What color is Iron in an oxidized soil? In a reduced? How can soil color be used to indicate soil wetness.

22) What directions can soil water move in?

23) What factors affect soil aggregation?

24) What gases are important in the global atmosphere; the soil atmosphere. What are their relative compositions and why is the soil different for certain gases in the soil atmosphere.

25) What is field capacity, and what is it based on? What is permanent wilting point, and what is it based on?

26) What is gley color?

27) What is isomorphous substitution? How does it occur in an aluminosilicate clay and give a soil a net charge? What ions with substitute for which other ions?

28) What is soil aeration? What soil properties does aeration affect and why? Explain in detail with figures.

29) What is the primary driving force for the movement of CO2 and O2 in soils? Draw a diagram to illustrate the differences between CO2 and O2 concentrations in soil vs atmospheric air. What would be the tendency for concentrations with increased depth?

30) What soil properties is gaseous exchange affected by? Explain in detail with figures.

31) Which soil type would you expect would be more susceptible to compaction? a) a sand soil with a bulk density of 1.0 g cm-3 and a constant particle size diameter, b) a clay soil with a bulk density of 1.0 g cm-3 and a constant particle size diameter, and c) a sandy loam soil with a bulk density of 1.0 g cm-3 and a wide distribution of particle sizes.

32) Why is water unique as a molecule? What are some of the unique properties of water?

33) Will a sandy loam hold more moisture than a clay loam? Why? Show with figures.

34) With the exception of adding other material, is soil texture easily modified? Explain with figures.

35) Will a sandy loam hold more moisture than a clay loam? Why? Show with figures.