TFL 46 Lewis to TEM Conversion
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INTRODUCTION
Ecosystem/terrain mapping was carried out for TFL 46 during the late 1980’s to early
1990’s. The principal objective of the project was to provide an information base for
wildlife management planning, as well as other operational forest management
applications. It has recently served as the framework for SIBEC-based forest level yield
analysis. The ecological classification system used in this project was developed by Dr. T.
Lewis and has been widely used in coastal mapping projects he has completed. The
system is conceptually very similar to BEC, and has been developed with cooperation
from Ministry of Forests ecologists. Where it differs is mainly in nomenclature, as most
“Lewis” classification units correlate directly to BEC units.
Polygon linework and ecosystem attributes are fully incorporated into the TimberWest
GIS database, while terrain attributes are partially loaded. The data is not to provincial
standards, and thus is not compatible with other provincial databases, nor the TEM
database available for TimberWest’s TFL 47.
The objective of this project is to modify and complete the ecological/terrain GIS
database for TFL 46 to make it consistent with provincial standards, to the degree
possible given the mapping methods employed at the time.
METHODOLOGY
The following tasks were completed for this project:

Completed mapping of approximately 11,000 ha excluded from the original mapping
coverage due to lack of available air photographs at the time. Linework was
delineated and attributes determined from airphoto interpretation (by T. Lewis) for
blocks at Hill 60, Nitinat Lake, Lake Cowichan, Weeks Lake, Muir Ck., and
Shawnigan Lake. Earlier ecosystem/terrain mapping completed by T. Lewis for BCFP
was digitized and used to fill an unmapped portion near the San Juan River.

Loaded terrain attributes for approximately 50% of the polygons which were missing
terrain attribute labels on the original typed airphotos. These were determined from
airphoto interpretation of the original typed photos (by T. Lewis) and added to the
digital attribute database.

Converted Lewis Ecosystem Mapping units (LEM) contained in the original
ecosystem database into TEM standard codes. This included biogeoclimatic unit, site
series, and site modifiers where feasible. This was based on existing classification
conversions available at TimberWest, with enhancements to reflect the current TEM
standards. Several iterations of the conversion table were prepared, reviewed and
revised as needed. Only gullied (g) and shallow (s) site modifiers were assigned
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based on available terrain attributes. Warm/cool aspect site modifiers were derived
separately as described below.

Prepared a theme for warm aspect/cool aspect site modifiers based on GIS processing
of TRIM data. This involved translating the DEM from TRIM, then creating a DTM
from the DEM. Slope and aspect coverages were then generated. This data was then
generalized to create a warm aspect, cool aspect, and gentle slope coverage using
criteria specified in the TEM standards. The data was retained in rastor format with
30m pixel resolution to facilitate any subsequent overlay analyses. Very steep warm
and cool aspects were not differentiated as separate classes as the areal coverage was
considered to be relatively minor for the study area.

Prepared a theme for structural stage based on GIS processing of the most current
forest cover data available from TimberWest. Documentation of the algorithm used to
process this theme is contained in the Appendix.

Prepared an expanded map legend based on the updated ecosystem database and the
information available from the original project.
DELIVERABLES
The following are the delivered items from this project:
1. ARC/IFNO files for site series and terrain theme (on CD)
 TimberWest version: filename TW_TFL46_ECO.e00
 TEM version: filename TEM_TFL46_ECO.e00
2. ARC/IFNO files for structural stage theme: filename TEM_TFL46_SS.e00 (on CD)
3. ARC/IFNO files for slope/aspect theme: filename TEM_TFL46.SA.e00 (on CD)
4. Draft check plots of each of the above three themes for one representative sheet1 from
the total of 21 TRIM mapsheets.
5. Comma separated value (CVS) file of the attribute database for the ecosystem and
structural stage data: filenames TEM_TFL46_ECO.cvs, TEM_TFL46_SS.cvs (on
CD)
6. Comma separated value (CVS) file for the project data form: filename ECOSYSTEM
PROJECT DATA_TFL46.cvs (on diskette)
7. Microsoft Word 97 files for the check plot legends, expanded legend, and project
report: filenames LEGENDS_TFL46.doc, EX_LEGENDS_TFL46.doc, and
TFL46_REPORT.doc, respectively (on diskette).
1
TimberWest has specified they do not want any paper copies of the maps.
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ISSUES
The following issues were identified during the preparation of the data and should be
considered when reviewing and working with it:
 only two site series and two terrain components were identified in the original
mapping
 the codes for biogeoclimatic unit were converted from the original mapped codes. A
query of the GIS data on this attribute revealed some discontinuity in the distribution
of biogeoclimatic units. Some of the obvious anomalies were cleaned up during the
editing phase. Additional work is required to fully clean this data to remove
distribution discontinuities.
 the boundary of the mapped area is irregular in some places as it follows polygon
boundaries rather than the legal TFL boundary. These were left as is at this time as the
TFL boundary is currently being revised. The spatial data can be clipped to the new
boundary once it is finalized.
 the shrub/herb structural stage doesn’t coincide exactly with wetland polygons in the
ecosystem coverage. This reflects more detailed differentiation of forested/nonforested areas in the forest cover data which would be encompassed within larger
“complex” ecosystem polygons containing shrub/herb wetlands with varying
proportions of forested ecosystem components.
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APPENDIX
ALGORITHM FOR DERIVING STRUCTURAL STAGE THEME FROM FOREST
COVER DATA
Data source


forest cover data extracted from TimberWest GIS database.
data input May 1998; data projected to 1997. Structural stage will therefore reflect
1997 conditions.
Fields utilized




NPCODE – non-productive forest codes were used to derive “non-treed” structural
stages including 1 (sparse), 2 (herb), and 3 (shrub/herb).
TOPHEIGHT – top height is based on species, site index, and age and was generated
in the TimberWest data from FREDDIE. Top height is used to differentiate str. stage
3 (shrub/herb) from classes 4+ based on 10 m height criteria.
DATEEST – year of stand establishment used to differentiate classes 4-7 based on
age criteria.
TIMBERTYPE – tree species composition. Used to identify deciduous stands (alder
and bigleaf maple dominated) to adjust age criteria for structural stages 4-6.
Algorithm Details
Step 1 – Process polygons which have NPCODE = not blank
NPCODE
Name
AL
alpine
BR
CL
GB
GP
IS
LA
NCBR
brush
cleared
gravel bar
gravel pit
islands
lake
non-commercial
brush
non-productive
not satisfactorily
restocked
no typing available
open range
road
river
rock
slide
NP
NSR
NTA
OR
RD
RI
RK
SL
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Structural
Stage
2
3
1
1
1
3
0
3
Comments
dwarf-shrub dominated (heathers); this is mostly
parkland communities
islands in rivers usually brushy
water
3
3
see explanation below
see explanation below
blank
2
1
0
1
1
data missing
herb fields
water
TFL 46 Lewis to TEM Conversion
SW
swamp
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3
most coastal bogs have >20% shrub and small tree
cover
NP EXPLANATION
Polys with NP have some attributes lost during data translation and the more specific
criteria are unclear. Generally they are very small swamps, rocks, etc. which may have
sparse tree cover. There is no other data available to refine the classification. We used
structural stage 3 (shrub/herb) as it should encompass the majority of these stands.
NSR EXPLANATION
All NSR polys are younger than 10 years (1987 is oldest) and heights will therefore be
less than 10 m. All NSR assigned to structural stage 3.
Step 2 – Process polygons which have NPCODE = blank
If TOPHEIGHT <= 10 then structural stage (ss) = 3
If TOPHEIGHT > 10 and:
If TIMBERTYPE = “deciduous” 2 and DATEEST > 1967 then ss = 4
If TIMBERTYPE = “not deciduous” and DATEEST > 1957 then ss = 4
If TIMBERTYPE = “deciduous” and DATEEST 1967 to 1937 then ss = 5
If TIMBERTYPE = “not deciduous” and DATEEST 1957 to 1917 then ss = 5
If TIMBERTYPE = “deciduous” and DATEEST 1936 to 1747 then ss = 6
If TIMBERTYPE = “not deciduous” and DATEEST 1916 to 1747 then ss = 6
If DATEEST < 1747 then ss = 7
Structural Stage Description
Code
Name
Criteria
blank
0
1
2
3
4
5
Missing data
Water
Sparse
Herb
Shrub/Herb
Pole/Sapling
Young Forest
6
Mature Forest
7
Old Forest
no forest cover data
lakes and rivers
non/sparsely vegetated
herb dominated (<20% shrub cover)
> 20% shrub cover; < 10 m tall
> 10 m tall and < 40 years (conifer) or 30 years (decid.)
>10 m tall and 40-80 years (conifer) or
30-60 years (decid.)
>10 m tall and 80-250 years (conifer) or
60-250 years (decid.)
> 10 m tall and > 250 years
2
deciduous where TIMBERTYPE = D, D(F), D(FH), D(H), D(HC), D(HF), D(HFS), D(HM), D(M),
D(MF), D(MH), M, M(HD), MD
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DATA DICTIONARY
1. Ecosystem data
TW3 field
TEM field
Description
Source
Ecosec
BGCunit
Zone
Subz/Var
Eco1_dec
Eco1_SS
Eco1_SM1
Eco1_SM2
Eco1_SM3
Eco2_dec
Eco2_SS
Eco2_SM1
Eco2_SM2
Eco2_SM3
Eco3_dec
Source
Eco_Sec
Eco3_SS
Eco3_SM1
Eco3_SM2
Eco3_SM3
Tdec1
Ttex1
SurfM1
SurfE1
Sttex1
SsurfM1
SsurfE1
Tdec2
Ttex2
SurfM2
SurfE2
Sttex2
SsurfM2
SsurfE2
Geop1
Geop2
Geop3
Unique
LEMcode
Site_S3
Site_M3a
Site_M3b
Data source (blank as not available for this project)
Ecosection (blank as not available for this project)
Biogeoclimatic unit
Biogeoclimatic zone
Biogeoclimatic subzone/variant
1st ecosystem component - % decile
1st ecosystem component – site series
1st ecosystem component – 1st site modifier
1st ecosystem component – 2nd site modifier
1st ecosystem component – 3rd site modifier
2nd ecosystem component - % decile
2nd ecosystem component – site series
2nd ecosystem component – 1st site modifier
2nd ecosystem component – 2nd site modifier
2nd ecosystem component – 3rd site modifier
3rd ecosystem component - % decile (blank as only 2 components
recognized in this project)
3rd ecosystem component – site series
3rd ecosystem component – 1st site modifier
3rd ecosystem component – 2nd site modifier
3rd ecosystem component – 3rd site modifier
1st terrain component - % decile
1st terrain component - texture
1st terrain component – surficial material
1st terrain component – surficial expression
1st terrain component – subsurficial texture
1st terrain component – subsurficial material
1st terrain component – subsurficial expression
2nd terrain component - % decile
2nd terrain component - texture
2nd terrain component – surficial material
2nd terrain component – surficial expression
2nd terrain component – subsurficial texture
2nd terrain component – subsurficial material
2nd terrain component – subsurficial expression
1st geomorphological process
2nd geomorphological process
3rd geomorphological process
Polygon number
Original Lewis Ecosystem Mapping map code
3
Bgc_Zone
Bgc_Subvrt
Sdec_1
Site_S1
Site_M1a
Site_M1b
Sdec_2
Site_S2
Site_M2a
Site_M2b
Sdec_3
Tdec_1
Ttex_1
Surfm_1
Surf_E1
Sttex_1
Ssurfm_1
Ssurf_E1
Tdec_2
Ttex_2
Surfm_2
Surf_E2
Sttex_2
Ssurfm_2
Ssurf_E2
Geop_1
Geop_2
Geop_3
Poly_Nbr
TW = TimberWest version of ecosystem data; TEM = TEM standard version of ecosystem data
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2. Structural Stage Data
Field
Description
Mapstand
Npcode
Timbertype
Topheight
Dateest
Prjdate
Strct_S
Polygon number
Non-productive forest codes
Species composition (e.g. HB(Yc)
Top height (based on spp., site index, and age; created from FREDDIE)
Year of stand establishment
Date stand attributes are projected to
Structural stage class
3. Slope/Aspect Site Modifier Data
Field
Slopeasp_Nam
Slopeasp_Cod
Description
Name of slope/aspect class (warm, cool, gentle)
Code for slope/aspect class (w=warm, k=cool, j=gentle)
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EXPANDED LEGEND
Ecosystem Legend
Introduction
This project provides ecosystem mapping of TimberWest Forest Ltd.’s TFL 46 located on
southern Vancouver Island. The mapping was originally undertaken during the late
1980’s to early 1990’s with the principal objective of providing an information base for
wildlife management planning and operational forest management planning. The
mapping was conducted by Dr. T. Lewis using an ecosystem classification system he
developed and applied extensively on Vancouver Island. This system is conceptually
similar to BEC and correlates directly to recognized BEC units in most cases.
This project represents a modification of the original ecosystem mapping to make
it consistent with standards outlined in “Standard for Terrestrial Ecosystem Mapping in
B.C. (RIC 1998), to the degree possible given the mapping methods employed at the time.
Map Legend
1. Biogeoclimatic Units
Map code
CWHxm
CWHmm1
CWHmm2
CWHvm1
CWHvm2
MHmm1
MHmmp1
2.
Name
Very Dry Maritime CWH Subzone
Submontane Moist Maritime CWH Variant
Montane Moist Maritime CWH Variant
Submontane Very Wet Maritime CWH Variant
Montane Very Wet Maritime CWH Variant
Windward Moist Maritime MH Variant
Parkland Windward Moist Maritime MH Variant
Site Series
TEM4
TW
Site Series Name
Typical Conditions
Site
Site
Series
Series
code
#
CWHXM VERY DRY MARITIME CWH SUBZONE
HK
01
HwFd – Kindbergia
gentle to moderate slope; deep, medium textured
soils
DC
02
FdPl – Cladina
gentle to moderate slope; ridge crests; very
shallow bedrock-dominated soil
DS
03
FdHw – Salal
gentle to significant slope, upper slope position;
shallow folisol and morainal soils
DF
04
Fd – Swordfern
significant slope; well drained, deep rubbly
colluvial soils
RS
05
Cw - Swordfern
gentle slope; deep, medium-textured fluvial soils
CWHmm1 Submontane Moist Maritime CWH Variant
4
TEM = 2 letter alpha code as per standards; TW = numeric code as per TimberWest database
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Moisture/
Nutrient Regime
SD-F/P-M
VD/P
MD/P-M
MD/R
SD-F/R-VR
TFL 46 Lewis to TEM Conversion
AP
01
HwBa – Pipecleaner
moss
FdHw – Salal
gentle to moderate slope; deep, medium textured
soils
DS
02
gentle to moderate slope; ridge crests; very
shallow, bedrock-dominated soil
HS
03
HwCw – Salal
gentle to significant slope, upper slope position;
shallow folisol and morainal soils
HF
04
CwHw – Swordfern
significant to gentle slope; well drained, deep
rubbly colluvial soils, and some shallow
limestone sites
AF
05
BaCw – Foamflower
gentle slope; deep, medium-textured fluvial
soils, and some shallow limestone sites
AS
07
BaCw – Salmonberry
gentle slope; lower receiving positions, medium
to fine-textured fluvial soils
RC
12
CwSs – Skunk cabbage poorly drained depressions and flats; deep
morainal and fluvial soils, usually with organic
veneers
CWHmm2 Montane Moist Maritime CWH Variant
AP
01
HwBa – Pipecleaner
gentle to moderate slope; deep, medium textured
moss
soils
DS
02
FdHw – Salal
gentle to moderate slope; ridge crests; very
shallow, bedrock-dominated soil
HS
03
HwCw – Salal
gentle to significant slope, upper slope position;
shallow folisol and morainal soils
AF
05
BaCw – Foamflower
gentle slope; deep, medium-textured fluvial
soils, and some shallow limestone sites
CWHvm1 Submontane Very Wet Maritime CWH Variant
AB
01
HwBa – Blueberry
gentle to moderate slope; deep, medium textured
soils
ABs
01s
HwBa – Blueberry
gentle, rolling topography; shallow to deep
/salal phase
morainal and occasionally glaciofluvial soils;
thick forest floors; dominant salal cover
HS
03
HwCw – Salal
gentle to significant slope, upper slope position;
shallow folisol and morainal soils
AF
05
BaCw – Foamflower
gentle slope; deep, medium-textured fluvial
soils, and some shallow limestone sites
HDs
06s
HwBa – Deer fern
moisture receiving areas in gentle, rolling
/salal phase
topography; shallow to deep morainal and
occasionally glaciofluvial soils; thick forest
floors; dominant salal cover
AS
07
BaCw – Salmonberry
gentle slope; lower receiving positions, medium
to fine-textured fluvial soils
SS
09
Ss – Salmonberry
high bench floodplain sites
CD
10
Act – Red-osier
medium bench floodplain sites
dogwood
CW
11
Act – Willow
low bench floodplain sites
YG
12
CwYc - Goldthread
poorly drained depressions and flats; deep
morainal and fluvial soils, usually with thick
forest floors
LS
13
Pl - Sphagnum
forested bogs on poorly drained organic soil
RC
14
CwSs – Skunk cabbage poorly drained depressions and flats; deep
morainal and fluvial soils, usually with organic
veneers
CS
25
Cw – Slough sedge
forested swamp; poorly drained depressions and
flats bordering wetlands, deep, medium B.A. Blackwell and Associates Ltd.
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F/P-M
MD/P
SD/P-M
SD/R
F/R
M-VM/R-VR
W/M-R
F/P-M
MD/P
SD/P-M
F/R
F/P-M
F/VP-P
SD/P-M
F/R
M-VM/VP-P
M-VM/R-VR
F-M/M-VR
F-M/M-VR
F-M/M
VM/P-M
W/P
W/M-R
VW/M-R
TFL 46 Lewis to TEM Conversion
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textured soil with organic veneer or blanket
CWHvm2 Montane Very Wet Maritime CWH Variant
AB
01
HwBa – Blueberry
gentle to moderate slope; deep, medium textured
soils
HS
03
HwCw – Salal
gentle to significant slope, upper slope position;
shallow folisol and morainal soils
AF
05
BaCw – Foamflower
gentle slope; deep, medium-textured fluvial
soils, and some shallow limestone sites
RC
11
CwSs – Skunk cabbage poorly drained depressions and flats; deep
morainal and fluvial soils, usually with organic
veneers
MHmm1 Windward Moist Maritime MH Variant
MB
01
HmBa – Blueberry
gentle to moderate slope; deep, medium textured
soils
MM
02
HmBa – Mountain
gentle to significant slope, crests and upper slope
heather
position; shallow folisol and morainal soils
MD
06
HmYc – Deer cabbage poorly drained depressions and flats; late snowlie areas with open forest cover
MHmmp1 Parkland Windward Moist Maritime MH Variant
MH
22
Hm - Mountaina mosaic of sites featuring islands of conifers
heather parkland
separated by heather-dominated communities;
shallow to moderately deep morainal, colluvial,
and folisol soils; gentle to significant slope;
highly complex due to impacts of varying snow
patterns
Non-Forested Units in All Biogeoclimatic Units
ES
31
Non-forested bog
very poorly drained bog wetland, on organic
soils
SA
51
Ds Avalanche tracks
active avalanche tracks dominated by Sitka alder
but may include stunted conifer cover
GP
GP
Gravel pit
NA
LA
LA
Lake
NA
RI
RI
River
NA
RO
RO
Bedrock
NA
3.
Site Modifiers
TEM
Code1
--5
g
-s
--
1
5
TW
Code
go
gu
ls
sh
ss
Name
Description
good
gullied
limestone
shallow
steep slope
more productive skunk cabbage sites
sites with common gullies
sites with limestone bedrock influence
sites with predominantly shallow (<1m) soils
sites with slopes 35-70%
see previous footnote
not applicable
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F/P-M
SD/P-M
F/R
W/M-R
F/P-M
SD/PM
VM/P-M
SD-M/P-M
NA
NA
NA
NA
NA
NA