SIBEC and Ecologically-based Yield Analysis

Predictive Ecosystem Mapping --

Technical Workshop

May 26-27, 2001

Victoria BC

Del MeidingerMOF Research Branch

SIBEC

• Site index (SI) estimates for biogeoclimatic ecosystem classification (BEC) site series

Treeless estimate:

An estimate of site index that is not directly based on tree or stand mensurational data.

Rather, it is usually based on productivity data assigned to units in a land classification. I

II

IIIIV

Treeless estimates

1. Classify the landbase into units

2. Gather productivity data by unit

3. Calculate average productivities by unit

The land classification approach

1. Gather site and productivity data

2. Perform regressions where SI = f (site factors)

3. Predict productivities using best equations

The site factor regression approach

Site Index Tool

(stand level)

Ages mostapplicable

(yrs)

Data requirements

site index curve/table 30-150 age, height

growth intercept table 3-30 (bh) age, height

SIBEC <3 and >150 BGC unit, site series

The Suite of Site Index Tools

Use SIBEC estimates when:

• time and/or money constraints preclude mensurational sampling

• site identification is available or obtainable

• moderate accuracy is required

• stand conditions are unsuitable for alternate methods

A brief history of treeless estimates

Classified landbase into 7 capability classes and 19 subclasses based on climate, soil, and vegatation. Maps with interpretive labels were produced at 1:125 K to 1:250 K.

Class 2, Subclass M(moisture deficit)

“White spruce under good management can yield 91-110 cu. ft. per acre.”

2MwS5H

alF

Class 5, Subclass H(low temperatures)

“Alpine fir under good management can yield 31-50 cu. ft. per acre.”

Example of a CLI Forestry Capability map

Canada Land Inventory, 1967

IIb

A brief history of treeless estimates

Krajina, 1969 (British Columbia)

Ia

IVa

IWHa, Picea engelmannii

A B C D E

0

1

4

2

3

7

6

5

Contours drawn on the edatopic griddelineated site index classes for each species in a biogeoclimatic unit.

Beckingham et al., 1996 (Saskatchewan)A brief history of treeless estimates

a b k

Site Index

Ecosite

Bar graphs showing site index by ecosite, by species. Tables by ecosite phases by species.

PjSbAtEp

Cajander, 1909 (Finland)

Cajander’s forest type classification based on ground vegetation. Later studies assessed productivity.

Site index (m @ 100yrs) by site type(Mikola, 1983)

Grove-likeheath

Dryish heath

Pine 26-30 20-25

Spruce 26-33 17-19

A brief history of treeless estimates

Ecosystem Management in BC

Site Classification

Site association

Site series

Site phase

Climate Classification

Biogeoclimatic zone

Biogeoclimatic subzone

Biogeoclimatic variant

Biogeoclimatic phase

ZonalSite

BEC

Management prescriptions by site series

Banner et al., 1993 (Prince Rupert Forest Region)

Regional field guide provides approximate site index by site series, by species. Notes on limiting factors also provided.

0 10 20 30 40

01

PlSx

HwBl

PlSx

HwBa

ICHmc2

Site Index

A brief history of treeless estimates

05

SIBEC Project History

• high proportion of stands where height/age curve method is unsuitable

• collation of the SIBEC database (Thrower / Blackwell / Oikos, 1995)

• data cleaning and summaries (1995, 1996)• regression analysis (Nemec, 1996)• intensive review (Regional Ecologists, 1996-1997)

First Approximation of Site Index Estimates by Site Series for Coniferous Tree Species of British Columbia, published January 1998

05

02

09

01

Soil Moisture

Soil Nutrients

Edatopic grid and site series

Mean site index by site series

Mean site Index by grid cell

Producing the SIBEC

Database Means

Estimates

• Models fitted by zone - species groups• Best model chosen for each group• Regressed estimates reported by grid cell and by site

series• Some values extrapolated and interpolated

Regression AnalysisProducing the SIBEC Estimates

SI = f (BEC, SMR, SNR, interactions)

Regression Output

S M R A B C D E

VD 0

MD 1 27.6(0)

22.4(0)

20.1(0)

SD 2 21.6(0)

22.4(1)

23.6(1)

SD 3

F 4 25.0(0)

23.7(0)

24.5(0)

23.5(0)

M 5 26.1(0)

18.9(0)

25.6(0)

VM 6 37.0(0)

25.5(0)

W 7

SI=27.6n=0se=5.1595% CI=7.39

ICHmc1, Pl

Data poor

Regression Output

S M R A B C D E

VD 0 10.9(1)

11.6(0)

13.7(10)

MD 1 22.5(1)

23.1(1)

25.2(1)

28.9(1)

31.2(0)

MD 2 22.5(8)

23.1(69)

25.2(41)

28.9(2)

SD 3 27.9(0)

28.6(32)

30.6(65)

34.4(19)

36.6(0)

F 4 28.6(0)

29.2(4)

31.3(72)

35.1(25)

37.3(4)

M 5 30.7(0)

31.3(1)

33.4(3)

37.1(31)

39.4(10)

VM 6 30.0(0)

30.7(0)

32.7(0)

36.5(7)

38.7(8)

W 7

SI=31.3n=72se=4.1595% CI=0.87

CWHxm, Fd

Data rich

Regional Ecologists’ ReviewProducing the SIBEC Estimates

• provide broad coverage • smooth out deviations due to small sample size• impose reasonable ecological trends at the extremes of the

data

Using database means for support, ecologists adjustedregressed estimates to:

Ecologist SIBEC data &regression output

Site Index Classes

Coast Interior

SI Class SI Class

… …14.0-17.9 16 10.5-13.4 12

18.0-21.9 20 13.5-16.4 15

22.0-25.9 24 16.5-19.4 18

26.0-29.9 28 19.5-22.4 21

… …

The SIBEC Guide

The SIBEC Guide

SISU Table

SiteSeries

Name Bl Fd Lw Pl Sx

01 HwCw - Falsebox 18M 24H 18H 24H 18M

02 Rhacomitrium - Cladonia X X X X X

03 FdCw - Prince’s pine __ 21L 24L 24M 18M

05 CwHw - Oak fern __ 24L 24M 24M 24L

08 CwSxw - Skunk cabbage X X X 18L 18L

Site Index Estimates by Site Series for Coniferous Tree Species of British Columbia

SISU

Free growing guidebook

Species Selection Table

SiteSeries

Name 1o 2o 3o

01 HwCw - Falsebox Fd Lw Pl Sx10 Bl

02 Rhacomitrium - Cladonia - - -

03 FdCw - Prince’s pine Fd Lw Pl - Bl

05 CwHw - Oak fern Fd9 Lw Sx Bl Pl -

08 CwSxw - Skunk cabbage Pl1 Sx1 Bl32 -

1 on elevated microsites 9 on south aspects10 on north aspects32 risk of frost damage

Species Selection Guidelines

Applying SIBEC

• Timber supply • SIBEC updates to MLSIS and ISIS• SITETOOLS, SIBEC look-up table

SIBEC for Timber Supply

spatial

non-spatial

Timber Supply

Analysis

TEM SIBECsamplingCANFOR Nimpkish

Interfor Phillips Arm

OASIS

PEMTelkwaNorth C.

WFP Vancouver Isl.

Bulkley TSA

SIBECtables

SIBECtables

Telkwa and North CoastStudy Areas

Ecologically based yield analysisusing site series to determine site

index

Data Flow

FC SI + VDYP => Standing volume

PEM/TEM => Area by site series (SS)

Management intent => species selection

SS+species => SIBEC => site index (SI)

species+SI => TIPSY => Yields

PEM + Yields => FSSIM => EcoYield

Telkwa area by age class and BEC variant

0

5000

10000

15000

20000

25000

0-50 51-100 101-150 151-200 201-250 251+

Age class

SBS mc 2

SBS dk

ESSF wv

ESSF mk

ESSF mc

CWH ws 2

Area (ha)

North Coast area by age class and BEC variant

0

5000

10000

15000

20000

25000

0-50 51-100 101-150 151-200 201-250 251+

Age class

Are

a (

ha)

MH mm 1

MH wh 1

CWH vm

CWH vh 2

Site series assignments

using EcoGen

Telkwa Forested Site series by BEC zone

0

5000

10000

15000

20000

25000

30000

35000

1 2 3 4 5 6 7 8 9 10 11 12

Site Series

Area (ha)

AT

SBS

ESSF

CWH

North Coast forested area by BEC and site series

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Site series

MH wh 1

MH mm 1

CWH vm

CWH vh 2

EcoGen determined site series

Next developmanagement assumptions.

Which species to grow?

Species regeneration - 4 scenarios:

Base: inventory species, use inventory SI

EcoA: inventory species, use SIBEC SI

EcoB: most productive species, SIBEC SI

EcoC: current practice species, SIBEC SI

Example Regenerated Species and Site IndexTelkwa - SBS - Base

0

2000

4000

6000

8000

10000

12000

14000

6 8 9 12 15 16 18 20 21 24 27 28

Site Index

Area (ha)

P

S

B

H

Example Regenerated Species and Site IndexTelkwa - SBS - EcoA

0

2000

4000

6000

8000

10000

12000

14000

6 8 9 12 15 16 18 20 21 24 27 28

Site Index

Area (ha)

P

S

B

H

Example Regenerated Species and Site IndexTelkwa - SBS - EcoB

0

2000

4000

6000

8000

10000

12000

14000

6 8 9 12 15 16 18 20 21 24 27 28

Site Index

Area (ha)

P

S

B

H

Example Regenerated Species and Site IndexTelkwa - SBS - EcoC

0

2000

4000

6000

8000

10000

12000

14000

6 8 9 12 15 16 18 20 21 24 27 28

Site Index

Area (ha)

P

S

B

H

SIBEC indicates the

site index

to expect for each species

The following graphs illustratethe result of the process -

Telkwa regenerated area by leading species

0

10000

20000

30000

40000

50000

60000

70000

Base EcoA EcoB EcoC

Management scenario

Interior Spruce

Lodgepole Pine

Hemlock

Balsam

Area (ha)

North Coast regenerated area by leading species

0

5000

10000

15000

20000

25000

30000

Base EcoA EcoB EcoC

Management scenario

Yellow Cedar

Sitka Spruce

Lodgepole Pine

Hemlock

Redcedar

Balsam

Area (ha)

Telkwa regenerated area by site index

0

10000

20000

30000

40000

50000

60000

70000

Base EcoA EcoB EcoC

Management scenario

28

24

20

16

12

8

Area (ha)

North Coast regenerated area by site index

0

5000

10000

15000

20000

25000

30000

Base EcoA EcoB EcoC

Management scenario

32

28

24

20

16

12

8

Area (ha)

Volume estimates

according to SI

VDYP, Spruce natural stands

0

100

200

300

400

500

600

700

5 20 35 50 65 80 95 110 125 140 155 170 185 200Years

Volume m3/ha

SI 8

SI 9

SI 12

SI 15SI 16

SI 18

SI 20

SI 28SI 27

SI 24

SI 21

SI 6

TIPSY, Spruce planted stands 1200 sph

0

100

200

300

400

500

600

5 20 35 50 65 80 95 110 125 140 155 170 185 200

Years

Volume m3/ha

SI 8

SI 9

SI 12

SI 15

SI 16

SI 18

SI 20

SI 28

SI 27

SI 24

SI 21

SI 6

Timber supply

modelling results

Telkwa Harvest Schedule

0

20

40

60

80

100

120

140

160

180

200

0 50 100 150 200

Years from now

Volume (000 m3/yr)

Base Harvest

Telkwa Harvest Schedule

0

20

40

60

80

100

120

140

160

180

200

0 50 100 150 200

Years from now

Volume (000 m3/yr)

Base Harvest

EcoA Harvest

Telkwa Harvest Schedule

0

20

40

60

80

100

120

140

160

180

200

0 50 100 150 200

Years from now

Volume (000 m3/yr)

Base Harvest

EcoA Harvest

EcoB Harvest

Telkwa Harvest Schedule All Scenarios

0

50

100

150

200

0 50 100 150 200

Years from now

Volume (000 m3)

Base Harvest

EcoA Harvest

EcoB Harvest

EcoC Harvest

North Coast Harvest SchedulesBase case flow as per TSR2

0

20

40

60

80

100

120

140

0 50 100 150 200

Years from now

Volume (000 m3/yr)

Base Harvest

North Coast Harvest SchedulesEcoA applies SIBEC SI to current species

0

20

40

60

80

100

120

140

0 50 100 150 200

Years from now

Volume (000 m3/yr)

Base Harvest

EcoA Harvest

North Coast Harvest SchedulesEcoB models the most productive species

0

20

40

60

80

100

120

140

0 50 100 150 200

Years from now

Volume (000 m3/yr)

Base Harvest

EcoA Harvest

EcoB Harvest

North Coast Harvest SchedulesEcoC models current regeneration

0

20

40

60

80

100

120

140

0 50 100 150 200

Years from now

Volume (000 m3/yr)

Base Harvest

EcoA Harvest

EcoB Harvest

EcoC Harvest

The accelerated short-term harvest leveldoes not impair long-term harvesting

0

50

100

150

200

250

0 50 100 150 200

Years from now

Volume (000 m3/yr)

North Coast base harvest

Telkwa EcoC accelerated short-term harvest

Telkwa base harvest

North Coast EcoC accererated short-term harvest

What makes the gain?

1. Higher SI means faster regenerated growth

2. Existing mature stands can be harvested faster

3. Replacement stands have larger volumes at earlier ages

Telkwa Area by seral stageBase Case

0

10000

20000

30000

40000

50000

60000

70000

5 20 35 50 65 80 95 110 125 140 155 170 185 200

Years

Area (ha)

Old

Mature

Immature

Early

Telkwa Area by seral stageEcoC Scenario

0

10000

20000

30000

40000

50000

60000

70000

5 20 35 50 65 80 95 110 125 140 155 170 185 200

Years

Area (ha)

Old

Mature

Immature

Early

North Coast Area by seral stageBase case

0

5000

10000

15000

20000

25000

30000

5 20 35 50 65 80 95 110 125 140 155 170 185 200

Years from now

Area (ha)

Old

Mature

Immature

Early

North Coast Area by seral stageEcoC Scenario

0

5000

10000

15000

20000

25000

30000

5 20 35 50 65 80 95 110 125 140 155 170 185 200

Years from now

Area (ha)

Old

Mature

Immature

Early

An alternative view is to model thebase case harvest level for allthe Eco scenarios.

This results in less disturbance ofthe forest in the long term.

Telkwa Area harvested for each scenario with the Base Case Harvest Level

0

100

200

300

400

500

600

700

0 20 40 60 80 100 120 140 160 180 200

Years From Now

Area(ha/yr)

Base Case

EcoB

EcoA EcoC

Also, EcoGen/SIBEC increases the THLB by increasing the areaabove the low-site value. In Telkwa TSR2 low-site cutoffs are:

Spruce < 10 mBalsam and hemlock < 11

mPine < 12 m

Telkwa - Blue area would be included in the TSR land base

0

10000

20000

30000

40000

50000

60000

70000

TSR Base EcoA

Are

a (h

a)

Less than Low-site cuttoff

Over Low-site cuttoff

Total area includedin this analysis

NC SIBEC Data -- Doubling sample size

No Change 42

Up 7

Down 0

Total 49

Pilot Project Limitations

• Telkwa– upper ESSF lower

SI– no new SIBEC

data– accuracy unknown

• North Coast– legacy BGC– size of area– accuracy unknown

Dealing with site classification and site index near boundaries

SBSmc2100%

SBSmc2/ESSFmc80:20

SBSmc2/ESSFmc60:40

SBSmc2/ESSFmc40:60

ESSFmc/01SI = 12

SBSmc2/01SI = 18

SI = 17SI = 16

SI = 14

ESSFmc100%

State of Knowledge

• still learning -- yield analysis– assumptions, effects

• uncertainties about PEM accuracy• SIBEC estimates -- 1st

approximation

Acknowledgements

• Management• Funding

• Research Br.• P.R. Region

• Funding• Project management

• Science Council of BC