Soil and Vegetation Connections
Making Connections 2nd Ed. Page 170-171
Can be obtained through the textbook glossary
2. a) how is topsoil formed?
Topsoil is formed very slowly as dead plants, leaves, and animals are decomposed by bacteria. The
decaying organic materials form humus, which gives the topsoil its dark colour.
3. Why is the size of rock particles important to soil structure?
The larger rock particles of sand allow rainwater to drain quickly through the soil, while the smaller
particles of clay prevent rapid drainage. A well-balanced mixture of both allows the soil to hold
moisture, and at the same time allows water to pass through at a rate moderate enough to allow
plants to take up nutrients.
4. Explain the difference between leaching and calcification.
Leaching occurs in areas of high precipitation (creating wet-climate soils); calcification occurs
in dry climate areas (creating dry-climate soils).
The leaching process is a downward movement of water through the soil; the calcification
process is an upward movement of water through the soil.
As leaching occurs, water dissolves the chemical nutrients and carries them downward; as
calcification occurs, water evaporates, leaving behind the minerals that were dissolved in it.
Leaching removes nutrients in the soil that plants need to survive; calcification builds up
nutrients and minerals in the upper portion of the soil.
Excessive leaching results in a poor, often thin, topsoil layer; excessive calcification results in a
layer of mineral deposits that is poisonous to plants.
**Diagram was drawn on the board during the soil note.
6. There are two classes of trees. Which one can survive a harsher climate? Why?
Coniferous trees can survive in a harsher (colder) climate because they have the following
Long roots are able to extract nutrients from the poor soil.
Sticky sap prevents the needles from freezing.
Waxy needles and thick bark prevent a loss of moisture in times of drought.
The needles and flexible branches easily shed snow to prevent damage.
The needles can conduct photosynthesis on warm days beyond the normal growing season.
7. Name the Canadian vegetation region which:
a) Is the largest Boreal and Taiga forest region
b) Is the smallest Deciduous forest region
c) Is the wettest West Coast forest region
d) Is the coldest Tundra region
8. Explain, in your own words, the term “transition zone.” Give an example and explain why this
vegetation region is a transition zone.
A transition zone is an area where the natural vegetation of one region gradually changes into
the natural vegetation of another region.
A transition zone is the line on a map that shows the boundary between one vegetation region
and another, but does not indicate and abrupt change in the natural vegetation.
A large transition zone is considered to be a vegetation region in itself.
A transition zone is the area where the climate and soil conditions of one region begin to
change into the climate and soil conditions of another region.
An example of a transition zone is the Mixed forest vegetation region. This region is located between
the Boreal and Taiga forest region and the Deciduous forest regions. The Mixed forest vegetation
region is a transition zone because it has the same type of natural vegetation, namely coniferous and
deciduous forests, as the two regions that border it. In the northern part of the region the climate is
similar to that of the Boreal and Taiga forest, while in the southern part of the region the climate is
similar to that of the Deciduous forest. The soil in northern parts of this transition zone is similar to
the leached, infertile soil of the Boreal and Taiga forest; in southern parts, it resembles the soil of the
12. “If you climb up a mountain, you will find a similar sequence of vegetation to that you would
find if you travelled from southern Canada to the high Arctic.” Explain why this is a valid statement.
As you climb up a mountain, the temperature decreases. With every increase in altitude, the air
becomes colder. The change in the mountains climate has a direct effect on the type of vegetation
growing up the mountainside. The warmer temperatures at the bottom encourage the growth of
deciduous and coniferous tress and the abundant groundcover in the form of grass, small plants, and
shrubs. Higher up, the deciduous trees start to disappear because they cannot survive the colder
temperatures. As the climate becomes even colder, the groundcover and shrubs begin to disappear.
The coniferous trees begin to thin out, and gradually disappear. All that remains is moss, and very
small plants growing between patches of bare rock. A snowcap sits on the very top of the mountain
As you travel from southern Canada to the high Arctic, the climate becomes colder. It affects
the vegetation in the same way that an increasingly colder climate affects the vegetation growing up a
mountainside. The weather in the Southeastern climate region of southern Canada is warm and we,
and encourages the growth o deciduous and coniferous trees. The dry climate of the Prairies does
not encourage the growth of trees, but the grass grows abundantly. North of the Prairies, the Boreal
and Taiga forest region has climate conditions that are harsher than those in the Mixed forest and
Grassland regions. These conditions prevent deciduous trees from growing, but the coniferous trees
still survive. Farther north, where temperatures are even colder, the coniferous trees begin to thin
out, until they gradually disappear. Above the tree line is the Tundra where only small shrubs, moss,
and lichen grow close to the ground, between patches of bare rock. In Arctic areas of the Tundra,
there is nothing but snow and ice.
13. Complete the chart
Vegetation Types of Natural Temperature Precipitation Soil Characteristics
Region Vegetation Characteristics Characteristics
Tundra -Shrubs, mosses, lichens, -Cold, short -Very little -Thin soils,
small flowers growing season precipitation, most permafrost
areas les than
Boreal and Taiga -Coniferous trees, e.g. -Cold temps -wet climate -very little humus
Forest white and black spruce, -short growing -shallow topsoil
balsam fir, pine season -grey-coloured
(evergreens), which lose topsoil
few needles -acidic
-Hardy deciduous trees -rainfall and
(poplar and white birch) snowmelts wash
in southern portion away soluble
-few organisms such
as bacteria and
Mixed Forest -coniferous and -temperate climate -regular, abundant -deep, grey-brown
deciduous trees (spruce, has warm summers topsoil rich in
fir, pine, cedar, hemlock, and cool winters minerals
maple, beech, ash, oak, -cold winds create -good supply of
birch) a harsh climate humus
-small shrubs, e.g. along the coast of -few soluble
junipers along the coast the Maritime minerals are
of the Maritime provinces removed from
provinces topsoil by leaching
-suitable for farming
Deciduous Forest -deciduous trees -long, hot summers -plentiful -less acidic than
(especially hardwood -minimum of five Mixed forest b/c of
trees such as maple, months of warm greater number of
beech, hickory, ash, black weather deciduous tress
walnut) -relatively mild -more humus than
winters Mixed forest
is dark brown
from topsoil by
-most fertile soil of
Grassland -drought-resistant short -cold winters, hot -very dry -limited amount of
-short grass grasses with root summers -limited rainfall humus
systems which forms a -high evaporation -calcified soils
sod mat -unsuitable for crops
-sagebrush and cactus -suitable for grazing
-trembling aspen, willow, cattle and other
and spruce grown only in animals
river valleys where
enough moisture is
-large amounts of
-long grass -cold winters, hot -dry humus that result in
summers -increased precip rich black soil
-just enough rainfall -richest soil in
to keep the minerals Canada
within easy reach of -produces some of
-long grass dotted with the grass roots the best grains in the
clumps of trees world
-coniferous trees more
common in the north -more precip than -transition soil
-parkland -deciduous trees -cold winters, hot grassed area, but between the rich
dominate in the south summers less than forested black soil of long
area grass and the grey-
coloured soil of the
Cordilleran -vegetation varies greatly -warmer in the -heavier rainfall on -soils of all types
Vegetation due to varying temps and valleys than high in the west side of -soils change
precip the mountains mountains completely wihin a
-grasses and catuses in -dry, hot valleys on -drier on the east short distance
dry, hot valleys on the east side of side of mountains -soil type
east side of mountains mountains -heavier determined by
-coniferous forests on -temps get colder precipitation on elevation, slope,
lower slopes where with elevation lower slopes rainfall, and veg
precipitation is heavier -snow and ice on the cover
-meadows of flowers and very highest slopes -in dry, hot valleys
shrubs similar to Tundra on east side of
veg on higher slopes mountains, soils are
above tree line similar to those in
-no veg on the very short grasslands
highest slopes -irrigation is often
-tundra soils and
bare rock on higher
slopes above tree
West Coast Forest -temperate rainforest -mild climate -heavy rainfall -lush veg provides a
(lush forests of Douglas lot of plant material
fir, Sitka spruce, red to make humus
cedar, western hemlock) -minerals leached
-trees more than 1m in deep into the soil
diameter, and over 50m