Soils Geography – Quiz 1
1)
(a) [1] Give an important soil process that involves at least 3 of the 4 major
components of soil?
(b) [1] Briefly describe how these components are involved in this process.
2)
(a) [1] Name a character of Metamorphic Rocks that determines its
resistance to weathering
(b) [1] Name a different character of Igneous Rocks that determines its
resistance to weathering
3)
While the weathering of mineral parent material is generally categorized
into physical & chemical mechanisms, biology can play a crucial role.
(a) [2] Name & briefly describe a Chemical weathering process mediated
by Biology?
(b) [2] … and for: a Physical weathering process mediated by Biology?
4)
(a) [1] In addition to Parent Material, what are the other 4 of the 5 major
factors that determine the type of soil found at a given location?
(b) [1] Describe briefly an example of how one of these influences soil
genesis.
Soils Geography – Quiz 2
1) [2] Differences in types and rates of what 4 processes lead to differences in soils,
and very broadly to the Soil Orders? - just name them
2) (a) [0.5] Name one Soil Order whose development is primarily driven by a climate
factor.
(b) [1.5] Draw & label a characteristic soil profile for this order
- Be sure to define any subscript horizon labels you use
(c) [1.0] Briefly explain how climate conditions led to the profile?
3) For one of the following 3 subsurface diagnostic layers – albic, argillic, cambic:
(a) [1.5] Briefly define the layer type
- Be sure to say if it’s an illuviated or eluviated zone (& define the term) or neither
(b) [0.5] Name one Soil Order that is characterized by this type of layer
(c) [0.5] What is the generic horizon label (=alpha symbol) for this layer in a soil
profile?
4) [2.5] Name the other Soil Orders not given in your answers to (2) & (3)
- Bonus [+1]: You can give these as a mnemonic that you created for all orders.
Soils Geography – Quiz 3
1) (a) [0.5] By Munsell’s color system, which of his generic colors is / are
present in a 2.5Y 2/3 soil?
(b) [0.5] Is this a dark or light soil? How is that evident in the color code?
(c) [0.5] Very roughly, what color is this soil in plain English?
2) [1] Name & very briefly describe the soil color that is used to delineate
wetlands in the US.
3) [2] Explain briefly how clay particles disproportionately affect the
properties of a soil?
4) (a) [2] Soil texture is only part of the story when it comes to soil dynamics
– what other soil structural characteristics strongly influence a soil’s
properties?  Name 4.
(b) [1.5] Name 6 properties that are affected by any or all of these
features?
5) [2] Macropores tend to dominate surface layers, micropores lower layers.
Briefly describe one effect this has on soil profile development.
Soils Geography – Quiz 4
1)(a) [0.5] Capillary flow is caused by what properties of water?
(b) [0.5] This flow causes soil water to rise higher but more slowly in what
general category of soil texture? Briefly (≤1 sentence) explain why?
2) (a) [1] Name the four most important components of soil water potential (ψ).
3) (a) [0.75] For saturated soil water flow –
i. Which ψ term is dominant?
ii. What soil structural elements are most involved?
iii. What benefits or negatives does this flow have for plant growth?
(b) [0.75] For unsaturated soil water flow – also answer (i-iii)
(c) [0.75] For vapor flow – also answer (i-iii)
(d) [0.75] For soil-plant root water flow - Which ψ term/terms play a key role?
4) (a) [1] Write out an equation for Darcy’s Law.
(b) [1.5] What does it tell us? Be sure to use & explain the terms ‘flux’ & ‘gradient.’
5)[2.5] “The soil-plant-atmosphere continuum” is said to be a major component of
the global hydrological cycle. (a) Why is this so (briefly)? (b) How does it work
(briefly)?
6) Bonus [+1]: What is one important detail regarding the soils (or a soil) in
(choose one): Europe, Africa, Latin America, Asia, or Australasia?
Soils Geography – Quiz 5
1) (a) [1] What is a soil association?
(b) [1] What is a catena? Include how this is distinguished from a toposequence.
2) (a) [1] Write a simplified equation to represent the terrestrial water balance – include
key terms (but you don’t need to be all inclusive). Be sure to define symbols.
(b) [1] Write a simplified equation to represent the land surface energy balance.
(c) [1] Explain briefly (1 sentence) how these 2 conservation equations are linked?
(d) [1] Why getting soil moisture content correct is critical for climate modeling?
3) Hysteresis is the general term for when the behavior of a process depends on the
sequence of events, such as for soil moisture on wetting vs drying.
(a) [1] Explain briefly why such hystereses can create a problem for modeling soil
processes in ecological models.
4) (a) [1] Briefly explain (in words, figure, or equation) – why do hilltops have a convex
surface, for surfaces at steady state?
(b) [1] According to Bob Anderson, the rounded crests of mountain ranges in the arid
US West are in equilibrium with the long-term climate of what period? These surfaces
are lowering at roughly what rate (ballpark)?
(c) [1] Are the shapes of steep-walled valleys between these crests in equilibrium?
Why?
Soils Geography – Quiz 6
1) (a) [1] Write out an equation for vertical heat flux within a soil
profile (subsurface). Be sure to define terms.
(b) [1] Which direction is heat flowing in the profile at point A? & B?
Think twice! - use your equation to explain why.
(c) [1] Name 2 soil properties that affect the rate of this heat flux.
A
B
2) (a) [1] Define “oxidation & reduction reactions.”
(b) [1] Write out an example reaction for one of these (be sure to say which one).
(c) [1] Name 2 processes through which soil O2 becomes depleted, affecting the
balance between oxidation & reduction.
3) (a) [1] Give an example of (i) a non-expansive clay & (ii) an expansive clay type. (give
a mineral name)
(b) [1] Compare & contrast their crystal structure (in terms of sheets, layers, etc.)
(c) [1] Explain with some detail why one is expansive and the other not as a result of
this structure.
4) (a) [1] What is the difference between alkaline & sodic soil?
Soils Geography – Quiz 7
1) [2] Name 4 soil properties that are affected by soil organic matter (SOM).
2) (a) [2] In SOM, what is the difference between Humus and Detritus? (define
them)
(b) [2] Do they affect soil fertility in the same way? Briefly explain.
3) [2] For Two of the following 5 groups of soil organisms, give an example and
name how it affects either nutrient cycling or soil properties, or is part of the
soil food web:
(a) Macroflora
(b) Macrofauna
(c) Mesofauna
(d) Microflora
(e) Microfauna
4) [2] What is the importance of SOM Carbon:Nitrogen ratio to microbial & plant
growth?
Soils Geography – Quiz 8
1) (a)[0.5] What process converts N2 gas from the atmosphere to biologically-available
forms?
(b)[0.5] In the case that this is biologically mediated – what organisms are involved?
(c)[0.5] And under what one critical micro-environmental condition?
(d)[0.5] Give one way that the organisms involved create this condition?
2) (a)[2.5] Draw out the path of the soil N cycle from fresh organic N material (e.g.,
proteins) to various inorganic forms and back to plants. *Be sure to name each process.
(b)[1] What benefits are gained by microbes involved in this pathway?
3) (a)[1] What ecological role do soil microbes play in the Colorado alpine in Winter? How
is this expressed in the Spring?
(b)[1] How can this occur in winter, a time usually considered to be outside the “growing
season”?
4)[2.5] Why is it the case that soil phosphorus is kept from being highly available to plants
at all pH levels, even when total soil P concentrations are high?
Soils Geography – Quiz 9
1) (a)[2] Briefly explain one way that land conversion alters soil processes in a manner
that contributes to global or regional climate change.
(b)[1] Name one way that climate change in turn affects these soil processes.
2) [1.5] Name 3 key sources of uncertainty that make projection of future climate
change and in turn future soil dynamics difficult.
3) (a)[1.5] Define the term ‘Human Ecological Footprint’
(b)[Bonus +1] The global per capita footprint has been decreasing over the last few
decades. What two changes might explain this?
4) (a)[1.5] Name 3 major ways in which we’re altering rates of N2 fixation (N2 to reactive N)
(b)[1] Roughly, what is the ratio of these human-mediated inputs to natural N fixation?
(c)[1.5] Name 3 environmental consequences of the human-altered global N cycle.
5) [Bonus +1] In an area with bedrock high in smectite (swelling clays), name one parent
material feature that will make all the difference as to whether a house supported on
pilings will be stable or torn apart.