The Soils of The Regional Municipality of Ottawa=Carleton

This should be done before forest management or establishment
activities commence. Contact your local Ontario Ministry
of Natural Resources field office for assistance in forest
management decisions.
(5) How toApply the Suitability Ratings Table
Before the suitability ratings table can be applied, one
must firstbe familiar withthe mapunit symbols which identify
the type of land area or areas represented by map delineations.
Recognition of the components of each symbol is necessary,
since the type of land areas upon which the ratings are based
account for at least one component of each symbol .
A map unit symbol may contain one or two components
representing types ofland areas . If it contains one such component,
only one set of suitability ratings for various tree species
apply. If itcontainstwo suchcomponents, however, two sets of
suitability ratings apply, one for each type of land area . When
two land area components are shown, the first one is dominant
in occurrence while the second occurs in significant proportions
. Refer to the section ofthe report, "Definitions ofTerms
and Components Associated with the Soil Maps and Legend,"
for more detailed explanations .
Once the types of land areas which are shown in a map
unit symbol have been determined, suitability ratings by species
for those areas can be found in Table 19 with one excep
tion . Land areas represented by a soil landscape unit and an
identified soil phase or phases constitute a separate land entity
for which additional ratings by species are given. Four types of
soil phases may be shown in a map unit symbol in conjunction
with a soil landscape unit . These are :
S- Shallow Phase - bedrock occurs at 50 to 100 cm depth
O-OrganicPhase -- 15 to 40 cm of organic material at the
surface
C-Coarse Phase - 15 to 40 cm of surface material significantly
coarser textured than the
underlying material
F-Fine Phase - 15 to 40 cm of surface material significantly
finer textured than the
underlying material
Other symbol components such as slope class or stoniness
class are not required to determine suitability ratings in the
table. These components were not considered in the interpre
tive process, but as discussed inthe section "Limitationsto the
Rating System," may be severe enough to warrant modification
ofthe givenratings for each tree species .
The following procedure should be followed when determining
the suitability ratings by species for the land area com-
ponent or components shown in a map symbol :
1 . Study the "Explanation ofthe Map Unit Symbols" shown
on the border of each soil map. Also refer to the section of
the report "Definitions of Terms and Components Associated
with the Soil Maps and Legend ." These provide explanations
of the various types of map unit symbols and their
respective components .
2 . Locate the symbol on the soil map for the area you are concerned
with .
3 . Identify the land area component or components . One or
two types ofland areas may be portrayed in amap unitsymbol,
which may be a soil landscape, land type, or miscellaneous
land unit as defined in the map legend .
4 . Identify any soil phases which are shown and the type of
land area or areas they are associated with . Only soil landscapeunits
have associated soil phases .
5 . Proceed to Table 19 . Suitability ratings by species are given
for all types of land areas without soil phases, and also for
those with soil phases .
6 . In the Land Area column, find each identified land area
with or without associated soil phases . Listed horizontally
beside each area are suitability ratings for eight commonly
planted forest tree species in eastern Ontario .
(6) Examples of Some Rating Determinations
(a) For a map symbol of C3
2
C3 is the land area component of the symbol for which
suitability ratings are given .
From Table 19, locate C3 in the land area column . Listed
horizontally beside C3 are the suitability ratings for eight
forest tree species, i .e. C3 is rated PU (Poor to Unsuitable)
for White Spruce (Sw) .
For a map symbol of F1-Gl
R2.3-S1 .2
F1 and GI are the land area components ofthe symbol for
which separate suitability ratings aregiven .
From Table 19, F1 is rated U (Unsuitable) for White Pine
(Pw), and G 1 is rated G (Good) forthe same species .
From the "Explanations ofthe Map Unit Symbols" on the
soil map, F 1 is the dominantly occurring land area, and G 1
occurs in significant proportions.
Thus, the delineated area is dominantly Unsuitable for
White Pine, with a lesser but significant proportion being
Good for the same species .