Soil and Vegetation Connections
Making Connections 2nd Ed. Page 170-171
Key Terms
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
characteristics:
 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
b) Is the smallest
c) Is the wettest
Boreal and Taiga forest region
Deciduous forest region
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.
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.
Example:
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
Deciduous.
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
all year.
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
Region
Tundra
Types of Natural
Vegetation
-Shrubs, mosses, lichens,
small flowers
Temperature
Characteristics
-Cold, short
growing season
Precipitation
Characteristics
-Very little
precipitation, most
areas les than
400mm
-wet climate
Boreal and Taiga
Forest
-Coniferous trees, e.g.
white and black spruce,
balsam fir, pine
(evergreens), which lose
few needles
-Hardy deciduous trees
(poplar and white birch)
in southern portion
-Cold temps
-short growing
season
Mixed Forest
-coniferous and
deciduous trees (spruce,
fir, pine, cedar, hemlock,
maple, beech, ash, oak,
birch)
-small shrubs, e.g.
junipers along the coast
of the Maritime
provinces
-temperate climate
has warm summers
and cool winters
-cold winds create
a harsh climate
along the coast of
the Maritime
provinces
-regular, abundant
Deciduous Forest
-deciduous trees
(especially hardwood
trees such as maple,
beech, hickory, ash, black
walnut)
-long, hot summers
-minimum of five
months of warm
weather
-relatively mild
winters
-plentiful
Grassland
-short grass
-drought-resistant short
grasses with root
systems which forms a
sod mat
-sagebrush and cactus
-trembling aspen, willow,
and spruce grown only in
-cold winters, hot
summers
-very dry
-limited rainfall
-high evaporation
Soil Characteristics
-Thin soils,
permafrost
-very little humus
-shallow topsoil
-grey-coloured
topsoil
-acidic
-rainfall and
snowmelts wash
away soluble
minerals
-leached soil
-infertile and
unsuitable for
agriculture
-few organisms such
as bacteria and
earthworms
-deep, grey-brown
topsoil rich in
minerals
-good supply of
humus
-few soluble
minerals are
removed from
topsoil by leaching
-suitable for farming
-less acidic than
Mixed forest b/c of
greater number of
deciduous tress
-more humus than
Mixed forest
-humus-rich topsoil
is dark brown
-some soluble
minerals leached
from topsoil by
abundant rain
-most fertile soil of
eastern Canada
-limited amount of
humus
-calcified soils
-unsuitable for crops
-suitable for grazing
cattle and other
animals
river valleys where
enough moisture is
available
-long grass
-grains
-oil seeds
-long grass
-parkland
-cold winters, hot
summers
-long grass dotted with
clumps of trees
-coniferous trees more
common in the north
-deciduous trees
dominate in the south
-cold winters, hot
summers
-dry
-increased precip
-just enough rainfall
to keep the minerals
within easy reach of
the grass roots
-more precip than
grassed area, but
less than forested
area
Cordilleran
Vegetation
-vegetation varies greatly
due to varying temps and
precip
-grasses and catuses in
dry, hot valleys on the
east side of mountains
-coniferous forests on
lower slopes where
precipitation is heavier
-meadows of flowers and
shrubs similar to Tundra
veg on higher slopes
above tree line
-no veg on the very
highest slopes
-warmer in the
valleys than high in
the mountains
-dry, hot valleys on
east side of
mountains
-temps get colder
with elevation
-heavier rainfall on
the west side of
mountains
-drier on the east
side of mountains
-heavier
precipitation on
lower slopes
-snow and ice on the
very highest slopes
West Coast Forest
-temperate rainforest
(lush forests of Douglas
fir, Sitka spruce, red
cedar, western hemlock)
-trees more than 1m in
diameter, and over 50m
high
-mild climate
-heavy rainfall
-large amounts of
humus that result in
rich black soil
-richest soil in
Canada
-produces some of
the best grains in the
world
-transition soil
between the rich
black soil of long
grass and the greycoloured soil of the
Boreal forest
-soils of all types
-soils change
completely wihin a
short distance
-soil type
determined by
elevation, slope,
rainfall, and veg
cover
-in dry, hot valleys
on east side of
mountains, soils are
similar to those in
short grasslands
-irrigation is often
required for
agriculture
-grey-coloured soils
under coniferous
forests
-tundra soils and
bare rock on higher
slopes above tree
line
-lush veg provides a
lot of plant material
to make humus
-minerals leached
deep into the soil