Soils form from weathered rock and organic matter. The type of soil depends on factors like the underlying bedrock, climate, vegetation, and slope steepness. In the Tongariro Volcanic Centre, soils vary from place to place based on local conditions. On the mountain peaks, there is little soil due to the cold temperatures and steep slopes. On the western slopes, the soils are deep but immature yellow brown pumice soils, as nutrient leaching occurs from heavy rainfall. On the eastern side, known as the Rangipo Desert, the soils are poor and sandy, as high winds and lack of vegetation leave the soil unprotected. In the Kaimanawas, the soils are fertile and

1. SOILS IN THE TVC
Learning Objective
• Understand the different ways in which a soil
can form and factors that can affect a soils
development
• Describe the characteristics of soils in
different regions and why they differ from
place to place

2. How are Soils Formed?
• Soils are a mixture of weathered rock and
organic matter
• Diagram of how soils are formed
• Diagram of soil profile

3. Soil Processes
The type of soil depends on:
 The _________ of the bedrock
 The type of _________ on top
 The climate
 The ________ – how steep the slopes are

4. Soil Processes Continued
On the volcanic plateau this means:
• Geology – mainly volcanic ash and scoria
• Vegetation – beech forests lower down slopes
and scrub or tussock nearer top
• Climate – cold which slows weathering and
wet which causes leaching of minerals
• Relief – steep slopes on mountains do not
allow deep soils to develop

5. GENERAL CHARACTERISTICS
Soils are __________ as volcanic ash is easily
_____________. However they are ___________
or not well developed without clear __________.
They are not fertile on the ________ side due to
the fact that there is limited _________ or organic
matter.

6. GENERAL CHARACTERISTICS
At the top of the ___________ the climate is too
cold for ____________ to occur and heavy rain
causes _____________ of nutrients so minerals ar
often lacking trace elements of Potassium and
__________ making the soils fairly barren.
On the _________ side there is more vegetation
and so more __________ can occur, this causes a
more _____________ soil to form.

7. Words to use for fill in the gaps
Eroded west horizons
Vegetation decomposition leaching
Cobalt mountains immature
Thick decomposition east
nutritious

8. Soil Characteristics and Patterns
The type of soil in the TVC varies from place to
place depending on the conditions there.
The patterns can be seen in four main areas:
• The Mountain Peaks
• The Western Slopes
• The Eastern Side (Rangipo Desert)
• The Kaimanawas

9. Use the information on the following four slides
to ANNOTATE the diagram on your worksheet
You need to annotate both the characteristic of
the soil and the reasons why that type of soil
develops.

10. Mountain Peaks
Little or no soils with most of area covered in bare
rock
Reasons:
Altitude above 2000 m therefore too cold (3 deg)
and strong winds and steep slopes

11. Western Slopes
Deep but immature yellow brown pumice soils
Reasons:
• Leaching of nutrients (esp cobalt) due to
orographic rainfall
• As slope decreases and vegetation and temp
increase decomposition occurs and deeper soils
develop.

12. Eastern Side (Rangipo Desert)
Poor sandy soils which will gain a hard ‘crust’ or
pan at the surface
Reasons:
• High W winds and lack of vegetation (tussock
and mat weed) mean soil is unprotected.
• Higher temps (12 deg) and rainshadow (1000
mm) mean water is evaporated leaving salts
behind

13. Kaimanawas
Fertile mature soils capable of sustaining larger
vegetation forms. Nutrient rich and deep.
Reasons:
• Gentler slopes and greater vegetation cover
(beech and podocarp)
• Higher temps therefore more decomposition
• Less affected by volcanic eruptions