management strategy and options for the tweedsmuir-entiako

Management Strategy andOptions for the Tweedsmuir-Entiako Caribou Winter Range

Land ManagementReport NUMBER

Province of British ColumbiaMinistry of Forests

83ISSN 0702-9861

1993

1 9 9 3

Ministry of ForestsResearch Program

Management Strategy and Optionsfor the Tweedsmuir-Entiako

Caribou Winter Range

Deborah B. Cichowski and Allen Banner

SEQ 5137 JOB LMR83-001-013 PAGE-0003 FRONT MATTER REVISED 14JUN00 AT 08:59 BY BC DEPTH: 60 PICAS WIDTH 42.09 PICAS COLOR LEVEL 1

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SUMMARY

Proposed logging on winter ranges of woodland caribou (Rangifer tarandus caribou) in west-central BritishColumbia, specifically the Tweedsmuir-Entiako area, precipitated the need for a timber harvesting strategycompatible with caribou winter habitat requirements. Information based on a study of caribou winter habitatselection and on an ecosystem map which emphasized the abundance of terrestrial lichens — the primarywinter food source of the caribou — was used to develop a management strategy for the winter range. Bothpotential direct and indirect effects of timber harvesting on the caribou population were considered. Themanagement strategy for the Tweedsmuir-Entiako caribou winter range comprises two levels of manage-ment: the landscape level (Caribou Management Zones); and the site-specific level (caribou habitat/timbervalues). Thirteen Caribou Management Zones were delineated, which identify areas of high (2), moderate (7),and low (4) value caribou habitat. Procedures for delineating Caribou Management Zones are described.

Caribou habitat and timber values were compared by using the PAMAP Geographic InformationSystem (GIS) to overlay the caribou habitat map (caribou habitat values) and the B.C. Ministry of Forestsforest cover map (timber values). The caribou habitat map was colour-themed according to caribou habitatvalue, and the caribou habitat/forest cover overlay map was colour-themed according to caribou habitat/forest cover value classes.

Six management options are proposed as part of the winter range management strategy. The impactsof those options on the timber supply were assessed using databases generated by the caribou habitat/forest cover overlay map. As well, the impacts of management options on the Tweedsmuir-Entiako caribouherd, and on the two Timber Supply Areas in the winter range, are discussed.


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ACKNOWLEDGEMENTS

Funding for this project was provided by the B.C. Ministry of Forests. D. Rasmussen, formerly of PrinceRupert Forest Region, Technical Services Section, compiled and produced most of the PAMAP GISproducts for the project. We thank him for his technical expertise. R. Marshall and A. Hetherington of B.C.Ministry of Environment, Lands and Parks, assisted with the delineation of Caribou Management Zonesand interpretation of some of the data. G. Hoehne and D. Robb of the B.C. Ministry of Forests provided TSAinformation and comments on earlier drafts of the report; K. MacKenzie assisted with data analysis andreport editing; I. Teske assisted with data entry; L. Malkow assisted with the GIS aspect of the project; andK. McKeown assisted with proofing and labelling of digitized maps and also with report editing. A. Deas,Character Graphics, Smithers, B.C., produced the figures. Final proofreading and preparation of thedocument for publication was done by H. Strongitharm, G. Montgomery, and other Technical Support Groupstaff, Forest Science Research Branch. Thanks also to H. Armleder, B. Brown, L. Dellert, J. Pojar,J. Vinnedge, B. McLellan, D. Seip, and S. Sullivan, of the B.C. Ministry of Forests, and D. Hebert, formerlyof B.C. Ministry of Environment, Lands and Parks for their advice and support for the project.


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TABLE OF CONTENTS

SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

ACKNOWLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv

1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

2 STUDY AREA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

3 CARIBOU WINTER HABITAT MAP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3.1 Ecosystem Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43.2 Predictive Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53.3 Caribou Habitat/Forest Cover Overlay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

4 TWEEDSMUIR-ENTIAKO CARIBOU WINTER RANGE MANAGEMENT STRATEGY . . . . . . . . . . 9

4.1 Procedures for Delineating Caribou Management Zones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94.2 Descriptions of Caribou Management Zones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

4.2.1 Caribou Management Zone 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114.2.2 Caribou Management Zone 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114.2.3 Caribou Management Zone 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164.2.4 Caribou Management Zone 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164.2.5 Caribou Management Zone 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164.2.6 Caribou Management Zone 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174.2.7 Caribou Management Zone 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174.2.8 Caribou Management Zone 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174.2.9 Caribou Management Zone 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174.2.10 Caribou Management Zone 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174.2.11 Caribou Management Zone 11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174.2.12 Caribou Management Zone 12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184.2.13 Caribou Management Zone 13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

4.3 Caribou Habitat/Timber Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184.4 Timber Supply Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

4.4.1 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194.4.2 Timber supply characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

5 MANAGEMENT OPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

5.1 Management Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265.2 Implications to the Tweedsmuir-Entiako Caribou Population . . . . . . . . . . . . . . . . . . . . . . . . . . . 265.3 Implications to the Timber Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

5.3.1 Short-term effects on the timber supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275.3.2 Long-term effects on the timber supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

6 DISCUSSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

6.1 Management Strategy for the Tweedsmuir-Entiako Caribou Winter Range . . . . . . . . . . . . . . 296.2 Management Options for the Tweedsmuir-Entiako Caribou Winter Range . . . . . . . . . . . . . . . 306.3 Future Information Needs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

6.3.1 Forest inventory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316.3.2 Tweedsmuir-Entiako caribou . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32


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7 RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

APPENDIX 1 Relationships between site units defined in this report and BiogeoclimaticEcosystem Classification (BEC) site units defined for the SBPSmc and SBSdk . . . . 34

APPENDIX 2 Raw data for Tables 6−8,13−16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

APPENDIX 3 Area inclusion factors for problem forest types in the Prince George TimberSupply Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

APPENDIX 4 Summary of net volume and Long Run Sustained Yield for Caribou ManagementZones in the Lakes TSA using current utilization standards . . . . . . . . . . . . . . . . . . . . . . 45

APPENDIX 5 Average mean annual increment (MAI) estimates for analysis units in the PrinceGeorge and Lakes Timber Supply Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

LITERATURE CITED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

TABLES

1 Summary of major site units used in mapping the Tweedsmuir-Entiako caribou winter range:site characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2 Summary of major site units used in mapping the Tweedsmuir-Entiako caribou winter range:vegetation characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

3 Summary of characteristics of Caribou Habitat Types found in the Tweedsmuir-Entiakocaribou winter range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

4 Summary of caribou habitat/forest cover overlay types found in the Tweedsmuir-Entiakocaribou winter range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

5 Summary of Caribou Management Zones of the Tweedsmuir-Entiako caribou winter range 11

6 Percent of each Caribou Habitat Type in each Caribou Management Zone in theTweedsmuir-Entiako caribou winter range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

7 Percent of each forest cover type in each Caribou Management Zone in theTweedsmuir-Entiako caribou winter range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

8 Percent of each Caribou Habitat Type/forest cover site class combination in each CaribouManagement Zone, in the Tweedsmuir-Entiako caribou winter range . . . . . . . . . . . . . . . . . . . . . . . 14

9 Percent of radio-collared caribou locations collected during five winters (1983/84 to 1987/88),occurring in each Caribou Management Zone during early winter (December to mid-January),mid-winter (mid-January to mid-March), late winter (mid-late March), and April . . . . . . . . . . . . . . 16

10 Possible site unit combinations of forested caribou habitat site units, in descendingorder of caribou habitat value, in the Tweedsmuir-Entiako caribou winter range . . . . . . . . . . . . . 19

11 Reductions (net downs) applied to the total land base for the Lakes and Prince GeorgeTimber Supply Areas, in the Tweedsmuir-Entiako caribou winter range . . . . . . . . . . . . . . . . . . . . . 20


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12 Reductions (net downs) to the total land base in each Caribou Management Zone,in the Tweedsmuir-Entiako caribou winter range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

13 Percent of netted down area in each Caribou Habitat Type, for each Caribou ManagementZone in the Tweedsmuir-Entiako caribou winter range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

14 Percent of the net land base in each Caribou Habitat Type, for each Caribou ManagementZone in the Tweedsmuir-Entiako caribou winter range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

15 Percent of total volume, on the net land base, in each Caribou Habitat Type, for eachCaribou Management Zone in the Tweedsmuir-Entiako caribou winter range . . . . . . . . . . . . . . . . 24

16 Percent of the Long Run Sustained Yield (LRSY) estimate, on the net land base, in eachCaribou Habitat Type, for each Caribou Management Zone in the Tweedsmuir-Entiakocaribou winter range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

17 Summary statistics for all Caribou Management Zones combined, within the Tweedsmuir-Entiako caribou winter range in the Lakes Timber Supply Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

18 Summary statistics for all Caribou Management Zones combined, within the Tweedsmuir-Entiako caribou winter range in the Prince George Timber Supply Area . . . . . . . . . . . . . . . . . . . . 25

19 Management options for the Tweedsmuir-Entiako caribou winter range . . . . . . . . . . . . . . . . . . . . . 26

20 Effects of management options for the Tweedsmuir-Entiako caribou winter range on theLakes Timber Supply Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

21 Effects of management options for the Tweedsmuir-Entiako caribou winter range on thePrince George Timber Supply Area and Vanderhoof Supply Block . . . . . . . . . . . . . . . . . . . . . . . . . 28

22 Relative effects of management options (% of Option 1) for the Tweedsmuir-Entiako caribouwinter range on the Lakes and Prince George Timber Supply Areas . . . . . . . . . . . . . . . . . . . . . . . 29

A2.1 Total area (hectares) of Caribou Habitat Types, forest cover types, and caribou habitat/forestcover combinations for all Caribou Management Zones combined in the Lakes and PrinceGeorge Timber Supply Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

A2.2 Total area (hectares) of each Caribou Habitat Type for each Caribou Management Zonein the Tweedsmuir-Entiako caribou winter range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

A2.3 Total area (hectares) of each forest cover type in each Caribou Management Zonein the Tweedsmuir-Entiako caribou winter range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

A2.4 Total area (hectares) of each Caribou Habitat Type/forest cover site class combination ineach Caribou Management Zone in the Tweedsmuir-Entiako caribou winter range . . . . . . . . . 39

A2.5 Total area (hectares) netted down in each Caribou Habitat Type, in each CaribouManagement Zone in the Tweedsmuir-Entiako caribou winter range . . . . . . . . . . . . . . . . . . . . . . 41

A2.6 Total area (hectares) of each Caribou Habitat Type in the net land base (after net downs),in each Caribou Management zone in the Tweedsmuir-Entiako caribou winter range . . . . . . . 41

A2.7 Volume of timber (m3), on the net land base, in each Caribou Habitat Type, for eachCaribou Management Zone in the Tweedsmuir-Entiako caribou winter range . . . . . . . . . . . . . . 42

A2.8 Long Run Sustained Yield (LRSY) estimates (m3/yr) for each Caribou Habitat Type, on thenet land base, in each Caribou Management Zone in the Tweedsmuir-Entiako caribouwinter range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

A3.1 Area inclusion factors for mature problem types in the Prince George Timber Supply Area,Supply Block D - Ootsa Public Sustained Yield Unit (PSYU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43


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A3.2 Area inclusion factors for Environmentally Sensitive Areas, and immature problem types inthe Prince George Timber Supply Area, Supply Block D - Ootsa PSYU . . . . . . . . . . . . . . . . . . 44

A4.1 Percent of volume (m3) in each Caribou Habitat Type, after net downs for each CaribouManagement Zone in the Lakes TSA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

A4.2 Percent of Long Run Sustained Yield (LRSY) estimates (m3/yr) in each Caribou HabitatType, after net downs, for each Caribou Management Zone in the Lakes TimberSupply Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

FIGURES

1 Location of the Tweedsmuir-Entiako study area in British Columbia, showing biogeoclimaticzone/subzone boundaries and the Timber Supply Area boundary . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2 Caribou use and availability of Caribou Habitat Types in the Tweedsmuir-Entiako caribouwinter range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3 Radio-collared caribou locations during winter (December to April) from 1983/84 to 1987/88in the Tweedsmuir-Entiako caribou winter range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

4 Location of 13 Caribou Management Zones in the Tweedsmuir-Entiako caribou winterrange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

SEQ 5179 JOB LMR83-024-001 PAGE-0001 PAGE 1 REVISED 14JUN00 AT 09:01 BY BC DEPTH: 59 PICAS WIDTH 42.09 PICAS COLOR LEVEL 1

1 INTRODUCTION

Proposed logging on the winter ranges of woodland caribou (Rangifer tarandus caribou) in west-centralBritish Columbia precipitated the need for a timber harvesting strategy that is compatible with caribouwinter habitat requirements. West-central British Columbia has been identified as a high priority manage-ment area for woodland caribou in British Columbia (Stevenson and Hatler 1985). The Tweedsmuir-Entiakoherd, which consists of about 500 caribou, is one of two caribou populations that inhabit that area.

During the summer, Tweedsmuir-Entiako caribou are found throughout northern Tweedsmuir Park inalpine and forested habitat. Most of the summer range is protected by Class A park status. In winter,however, caribou migrate to low elevation forested habitat east of Tweedsmuir Park, in the Entiako Lakearea. Although little timber harvesting has occurred in the winter range, harvesting has been proposed overthe next 20 years for the two Timber Supply Areas in the winter range (Lakes TSA, Prince Rupert ForestRegion; and Prince George TSA - Vanderhoof Supply Block, Prince George Forest Region).

Before the early 1980s, little information was available on the winter habitat requirements of theTweedsmuir-Entiako caribou. In 1983, the B.C. Ministry of Environment began monitoring radio-collaredcaribou to determine basic seasonal movements and habitat use. From 1985 to 1988, an intensive studywas conducted on winter resource selection and population status to determine potential impacts of timberharvesting on the caribou population and on the winter range (Cichowski 1989). The study demonstratedthat, during winter, caribou selected mature forested habitats, and foraged primarily by digging through thesnow (cratering) to obtain terrestrial lichens. Arboreal lichens were also used, but to a lesser extent thanterrestrial lichens, and became more important when snow depth or hardness impeded digging by caribou.

Terrestrial lichen (Cladina spp., Cladonia spp.), which constituted the primary winter food source forcaribou, are slow growing, and are associated with late successional stages (Ahti 1977; Johnson 1981).Terrestrial lichens are poor competitors against vascular plants and are most abundant on drier, lessproductive sites (Kershaw 1977; Hale 1983; Rowe 1984). Because they are highly susceptible to mechani-cal damage, and regeneration of lichens after disturbance may take 50−100 years (Hale 1983; Rowe1984), it is expected that logging would directly affect caribou through destruction of their primary winterfood source. Once a site has been logged, it will be unavailable as caribou winter feeding habitat for at least50 years.

Potential indirect impacts of logging on caribou include increased human disturbance, hunting andpoaching as a result of improved access, and altered predator-prey relationships. An anti-predator strategyof woodland caribou is to space out over very large areas so that it is harder for predators to find them(Bergerud et al. 1984; Bergerud and Page 1987). Caribou populations therefore exist at low densities. If theamount of mature forest that caribou can occupy is decreased, then the density of caribou in the remainingstands will be increased, probably resulting in greater predator efficiency. Predator efficiency may also beincreased during winter if roads and snowmobile tracks provide easier travel routes for wolves (Edmondsand Bloomfield 1984).

As well, logging, like fire, converts mature forest into early successional stages, creating habitatfavoured by moose (Alces alces). An increase in numbers of moose can support a larger predatorpopulation and can result in increased predation pressure on caribou. In southeastern British Columbia,predation pressure on woodland caribou was lower in Wells Gray Park, where caribou were spatiallyseparated from moose (the alternative prey), than in the Quesnel Highlands where less spatial separationexisted (Seip 1992). In Ontario, the southern limit of woodland caribou has receded during the last 100years, coincident with the northern range expansion of white-tailed deer (Odocoileus virginianus) andmoose (Darby et al. 1989). Wolf (Canis lupus) predation has been implicated as the major limiting factor ofwoodland caribou populations in Alaska, the Yukon, western Alberta, and southeastern British Columbia(Gasaway et al. 1983; Farnell and MacDonald 1987; Edmonds 1988; Seip 1992).

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2

In the Tweedsmuir-Entiako area, although the primary limiting factor of the caribou herd has not beendetermined, the population appears to be declining.1 Any potential negative direct or indirect effects oflogging on caribou could further contribute to the decline. It is therefore essential that a managementstrategy for the Tweedsmuir-Entiako caribou winter range consider both the potential direct and indirecteffects of logging on woodland caribou populations.

In addition to the information collected on caribou winter ecology, the Tweedsmuir-Entiako caribouwinter range was mapped and its caribou habitat value interpreted. Based on results indicating thatterrestrial lichens were the primary food source for the Tweedsmuir-Entiako caribou during winter, the B.C.Ministry of Forests Research Section developed an ecosystem map for the winter range, emphasizingterrestrial lichen abundance (Clement et al. 1987) and identifying areas of high caribou habitat capability.

The ecosystem map, together with information on caribou winter resource selection and on thepotential effects of logging on woodland caribou populations, was used to develop a management strategyfor the study area. The strategy involved two levels of management: the landscape level (CaribouManagement Zones), which addressed the caribou winter range in its entirety and identified areas of highcaribou winter range capability; and the site-specific level, which addressed the relative values of caribouhabitat and timber on individual sites within each Caribou Management Zone. Caribou Management Zoneswere based on caribou habitat values and caribou use. Colour-themed maps combining caribou habitat andtimber value information were produced using the PAMAP Geographic Information System (GIS) (PAMAPGraphics Ltd. 1989).2 Six management options were then developed for the winter range based on CaribouManagement Zones, caribou winter resource selection, and potential impacts of logging on the caribouwinter range. Integration of the caribou habitat and forest cover information (databases generated byPAMAP) allowed us to analyze the implication of each management option for the timber supply in thewinter range.

The purpose of this report is to:

1. describe the methods used in developing the management strategy for the Tweedsmuir-Entiakocaribou winter range;

2. describe each Caribou Management Zone and summarize the caribou habitat and current timbersupply characteristics of each; and

3. discuss the six management options and their implications to woodland caribou and to the timbersupply.

This report addresses only caribou habitat and timber values. It does not attempt to consider all aspects ofthe Entiako ecosystem.

1 Cichowski, D.B. [1993]. Population status of woodland caribou in west central British Columbia. B.C. Min. Environ., Victoria, B.C.Wildl. Bull. In preparation.

2 1:50 000 colour-themed maps are on file at the B.C. Ministry of Forests, Forest Science Section, Smithers, B.C. and at Ministry ofForests District Offices, Burns Lake, B.C. and Vanderhoof, B.C.

3

2 STUDY AREA

The winter range of the Tweedsmuir-Entiako caribou herd is located in west-central British Columbia, eastof northern Tweedsmuir Park (Figure 1). The area includes portions of two Timber Supply Areas (TSA): theLakes TSA, which supplies the Burns Lake District of the Prince Rupert Forest Region; and the VanderhoofSupply Block of the Prince George TSA, which supplies the Vanderhoof District of the Prince George ForestRegion. Most of the winter range lies between 850 and 1300 m on the Nechako Plateau region of theInterior Plateau, and is characterized by flat or gently rolling terrain (Holland 1976). The round-toppedFawnie Mountains rise up from the Nechako Plateau to 1920 m in the eastern portion of the study area.Most of the study area is included within the moist cold subzone of the Sub-Boreal Pine−Spruce Biogeo-climatic Zone (SBPSmc of Pojar et al. 1988; referred to as the SBSa2 in Lewis et al. 1986). A dry, coolsubzone of the Sub-Boreal Spruce Zone (SBSdk) occurs in the northern portion of the study area and theEngelmann Spruce−Subalpine Fir Zone (ESSF) occurs above 1200 m in the Fawnie Mountains, below theAlpine Tundra Zone (AT). Only the SBPS and SBS zones were mapped because they encompass most the caribou winter habitat.

Low elevation forests consist mostly of lodgepole pine (Pinus contorta) or mixed lodgepole pine/whitespruce (Picea glauca) stands.3 Spruce stands occur primarily on wetter seepage sites and as bands alonglakes and wetlands. Black spruce (Picea mariana) is generally restricted to forested wetlands, as well as cooler north and east facing upland sites. Subalpine fir (Abies lasiocarpa) occurs only at higher elevations the eastern and (though rarely) northern-most part of the study area. Deciduous stands of trembling aspen(Populus tremuloides) are not extensive except in the northern portion of the study area. Lakes and sedgefens are common and often occur in mosaics of lakes, fens, and fringe forests of spruce.

FIGURE 1. Location of the Tweedsmuir-Entiako study area in British Columbia, showing biogeoclimaticzone/subzone boundaries (solid lines) and the Timber Supply Area boundary (dashed line).Zone/subzone abbreviations are explained in the text.

3 Plant species nomenclature follows Taylor and MacBryde (1977, 1978) for vascular plants, Hale and Culberson (1970) for lichens,and Ireland et al. (1980) for mosses. .

of

into

SEQ 5145 JOB LMR83-003-014 PAGE-0004 CHAP 3 REVISED 14JUN00 AT 08:59 BY BC DEPTH: 60 PICAS WIDTH 42.09 PICAS COLOR LEVEL 1

4

Most of the pine and pine/spruce stands that dominate the study area have poorly developed shruband herb layers. Common understory vascular plant species are Shepherdia canadensis, Spiraeabetulifolia, Rosa acicularis, Arctostaphylos uva-ursi, Linnaea borealis, Cornus canadensis, and Vacciniumcaespitosum. The relative abundance of mosses versus lichens on the forest floor is related to landform andsoil texture as they affect soil moisture. Mesic sites that occur on medium to fine textured morainal blanketsare dominated by mosses, mainly Pleurozium schreberi and Ptilium crista-castrensis, with generally lessthan 1% lichen cover. Drier stands on coarser textured tills and glaciofluvial sands and gravels typicallyhave from 30 to 50% cover of ground lichens (mainly Cladina and Cladonia spp. and Stereocaulon spp.),and these sites represent the best winter habitat for caribou. Wet, spruce-dominated forested communitieshave relatively lush shrub and herb understories with virtually no ground lichens. The exceptions are theopen white/black spruce fringe forests adjacent to wetlands where Cladina and Cladonia spp. frequent themossy hummocks or gravelly/cobbly substrates. Arboreal lichens (primarily Bryoria spp.) occur throughoutthe forested habitats, but are especially abundant in forested wetlands and spruce fringes surroundinglakes and fens.

The study area lies within the rainshadow of the Coast Mountains and is characterized by a drycontinental climate. Summers are typically cool, short, and dry, and winters are very cold, long, and dry.Soils throughout the winter range are predominantly Brunisolic Gray Luvisols and Dystric Brunisols onmorainal and glaciofluvial deposits (Lewis et al. 1986, Clement et al. 1987).4

3 CARIBOU WINTER HABITAT MAP

The caribou winter habitat map was developed from preliminary results of the winter resource selectionstudy which indicated that terrestrial lichens were the primary winter food source for caribou in theTweedsmuir-Entiako area. The purpose of the map was to identify areas of high caribou habitat capability(based on terrestrial lichen abundance), and to assist in developing a management strategy for the winterrange. Digitized caribou habitat maps were also combined with forest cover information, using GIS, toassess impacts of management strategies on the timber supply.

3.1 Ecosystem Mapping

The study area was mapped at a scale of 1:50 000 according to ecosystem mapping procedures outlined inBanner et al. (1986) and Mitchell et al. (1989). Only the SBPS and SBS Biogeoclimatic Zones outsideTweedsmuir Park, comprising 289 773 ha or 86% of the total study area, were mapped. Site units weremodified from an ecosystem classification for the area that had been previously developed by the B.C.Ministry of Forests (Lewis et al. 1986; B.C. Ministry of Forests 1990). Characterization of site units focusedon terrestrial lichens, the primary winter food source for these caribou. An open map legend (Mitchell et al.1989) was developed based on vegetation characteristics, especially terrestrial lichen abundance, and ageclass. Site units are summarized in Tables 1 and 2. Dry Lichen (DL) units contained the most terrestriallichen, and Moss (M) and Seepage Forest (SF) units contained few or no terrestrial lichens. Wetlands hadfew terrestrial lichens, but trees found in forested wetlands or along the edge of wetlands supportedabundant populations of arboreal lichens.

Preliminary typing was done on 1:50 000 black and white aerial photographs, based on vegetative andterrain features. Map delineations (polygons) were labelled according to site units and stand age classesthat occurred within them. Although some polygons were mapped as pure units (e.g., LM4), complexes oftwo or three site units were common (e.g., LM4/M3 denoting approximately equal proportions, or DL4//LM3/M4denoting DL as the dominant unit with equal proportions of the two remaining site units). Polygon boundariesand labels were verified on the ground either by detailed plot (vegetation, soil, mensuration) sampling

4 Soil classification follows the Canadian System of Soil Classification (Agriculture Canada Expert Committee on Soil Survey 1987).


5

(107 samples), or by rapid polygon inspections along ground transects. Of the 1566 polygons within themap area, 20% were ground-truthed and the remainder were labelled through aerial photo interpretation oraerial reconnaissance (helicopter). Polygon boundaries were transferred (Kail-plotted) onto four 1:50 000base maps and digitized for use on the PAMAP system. The study area is covered by 25 1:20 000mapsheets.

TABLE 1. Summary of major site units used in mapping the Tweedsmuir-Entiako caribou winter range: sitecharacteristics (based on Clement et al. 1987)

Site unita Name Parent material Soil Great Groupb Humus formc Soil particle sizeb Soil drainage

DL Dry Lichen Glaciofluvial; Dystric Brunisols; Xeromors; Sandy; Sandy- Rapidoften eskers Regosols Hemimors Skeletal

LM Lichen - Moss Morainal and Dystric Brunisols; Hemimors Fine loamy to Wellglaciofluvial Grey Luvisols Sandy; seldom

Skeletal

M Moss Morainal; occ. Dystric Brunisols; Hemimors Fine loamy Mod. wellglaciofluvial and Grey Luvisols to Loamylacustrine

AF Aspen Forb Morainal; colluvial; Grey Luvisols; Mormoders; Fine loamy Mod. well to wellS. and W. facing Sombric Brunisols Leptomoders to Loamyslopes

SF Seepage Forest Fluvial; morainal; Humic and Orthic Mormoders; Sandy to Imperfect to poor(organic) Gleysols; Cumulic Hydromoders Fine loamy

Regosols

SF(2) Seepage Forest; Morainal; generally Gleyed Grey Hydromors; Clayey to Course Imperfect to poorGlow moss adjacent to wetlands Luvisols; Orthic Histomoders loamy; oftenphase Gleysols cobbly (skeletal)

at surface

FW and Forested and Organic over Typic Fibrisols; Histomors; Organic Very poorNW Non-forested morainal and Typic Mesisols Histomoders

Wetlands fluvial

a Relationships between the site units defined in this report and the existing site series defined for the SBSPmc and SBSdk aredescribed in Appendix 1.

b Soil classification and particle size terminology follows Agriculture Canada Expert Committee on Soil Survey (1987).c Humus form classification follows Klinka et al. (1981).

The large number of polygons consisting of a complex of two or more site units resulted in a very largenumber of unique map units. We therefore needed to generalize the map units into a manageable numberof broader map unit classes. We called these classes Caribou Habitat Types (Table 3). Site unit polygonswere colour-themed according to Caribou Habitat Type classes described in Table 3. Forested CaribouHabitat Types in Table 3 are listed in descending order of caribou habitat value, based on terrestrial lichenabundance. Although arboreal lichens were also used by caribou during winter, ecosystem mappingconcentrated on terrestrial lichen abundance. Arboreal lichen abundance was difficult to predict using theecosystem map.

3.2 Predictive Value

To test the predictive value of the caribou winter habitat map we compared the use of Caribou HabitatTypes by caribou (based on the number of radio-collared caribou locations) to the availability of thosehabitat types (based on the total area of each habitat type) (Cichowski 1989). Those habitats that were usedsignificantly greater than they were available were considered high value habitat. Use of mature DryLichen−Lichen Moss (DLLM), and Lichen Moss (LM) habitats by caribou exceeded availability of thosehabitat types; use of Moss/Dry Lichen−Lichen Moss (MDLLM) and Moss−Seepage Forest/Aspen Forest(MSF/AF) habitat types was less than availability (Figure 2). There was no difference between use andavailability of the Dry Lichen−Lichen Moss Ecomosaic (MOSAIC) habitat type. Selection of Caribou Habitat


6

Types by caribou reflected the values assigned to each habitat type, confirming the validity of using thecaribou habitat map as a predictor of caribou habitat value.

3.3 Caribou Habitat/Forest Cover Overlay

Forest cover maps from the B.C. Ministry of Forests were used to integrate caribou habitat information withtimber information. Cichowski (1989) tested the forest cover map — in addition to the caribou winter habitatmap — as a predictor of caribou winter habitat value. Forest cover units were grouped according todominant tree species present, site class (low, poor and medium) based on the new Goudie site index (B.C.Ministry of Forests 1990), and age class (immature: 0−80 years; mature: >80 years). Caribou selectedprimarily mature pine stands on low and poor sites (Cichowski 1989). The caribou habitat and forest covermaps were over-laid using the GIS of PAMAP, and the overlay map was colour-themed according to overlayclasses, based on caribou habitat selection patterns discussed above (Table 4). The overlay map was usedto identify sites of potential conflict between caribou habitat and timber values.

TABLE 2. Summary of major site units used in mapping the Tweedsmuir-Entiako caribou winter range:vegetation characteristics (based on Clement et al. 1987)

Site unitsLayer/species

DLa LM M AF SF SF(2) FW NW

TREESPicea glauca -b * ** - *** ** * -Picea mariana * * * - - ** *** *Pinus contorta *** *** *** - * ** * -Populus tremuloides - - * *** * - - -

SHRUBSShepherdia canadensis ** ** * ** - - - -Spiraea betulifolia ** ** ** ** * * - -Rosa acicularis ** ** * ** * - - -Juniperus communis * * * - - - - -Lonicera involucrata - - * * ** * * -Vaccinium membranaceum - * * * * * - -Ledum groenlandicum - - - - - * *** **Betula glandulosa - - - - - ** *** ***Alnus incana - - - - ** ** ** **Salix spp. - - - - * ** ** **

HERBSArctostaphylos uva-ursi ** ** ** ** - - - -Vaccinium caespitosum * ** ** * - - * *Linnaea borealis * ** ** * * ** * -Cornus canadensis - * ** ** * ** * -Empetrum nigrum * * - - - ** *** **Equisetum arvense - - - - *** ** ** -Calamagrostis canadensis - - * * ** ** ** -Petasites palmatus - - * * ** * * -Aster conspicuus - - - ** - - - -Elymus glaucus - - - ** - - - -Carex spp. - - - - * * ** ***

BRYOPHYTES AND LICHENSCladina/Cladonia spp. *** ** * - - ** * *Stereocaulon spp. * * - - - - - -Peltigera spp. ** ** * - - ** * -Pleurozium schreberi * ** *** * ** ** - -Ptilium crista-castrensis * * ** * ** * - -Hylocomium splendens - * ** * ** * - -Aulacomnium palustre - - - - - ** * *Sphagnum spp. - - - - * ** *** ***

a Site unit abbreviations are explained in Table 1. On the ecosystem map, site units are also given an age class descriptor (e.g., LM4)as follows: 1 = 0−10 yr, 2 = 11−40 yr, 3 = 41−80 yr, 4 = 81−120 yr, 5 = greater than 120 yr.

b Species abundance codes as follows: (-) absent, (*) infrequent, (**) common, (***) widespread to dominant.

7

TABLE 3. Summary of characteristics of Caribou Habitat Types found in the Tweedsmuir-Entiako caribouwinter rangea

Caribou Habitat Type Description and associated polygon units b

DLLM Dry Lichen/Lichen Moss- includes dry lichen/lichen moss combinations and dry lichen leading and dominant over moss

DL, DL/LM, DL//LM, LM/DL, LM//DL, DL//M, DL/M

LM Lichen Moss- lichen moss leading and dominant over moss

LM, LM//M, LM/M

DLLM Dry Lichen/Lichen Moss EcomosaicMOSAIC - combinations of dry lichen or lichen moss with adjacent wetlands or seepage forests

DL/SF, DL/W, W/DL, SF/DL, DL//SF, DL//W, W//DL, SF//DLLM/SF, LM/W, W/LM, SF/LM, LM//SF, LM//W, W//LM, SF//LM

MDLLM Moss - Dry Lichen / Lichen Moss- moss leading and dominant over dry lichen or lichen moss; includes dry lichen or lichen moss as a third

unit with combinations of moss and seepage forest as the first two unitsM//DL, M//LM, M/DL, M/LM, M/SF/DL, M//SF/DLM/SF//DL, M//SF//DL, SF/M/DL, SF//M/DL, SF/M//DL,SF//M//DL, M/SF/LM, M//SF/LM, M/SF//LM, M//SF//LM,SF/M/LM, SF//M/LM, SF/M//LM, SF//M//LM

MSF/AF Moss/Seepage Forest−Aspen Forest combinations- combinations of moss and seepage forest and aspen forest without dry lichen or lichen moss as the third

unit; aspen forest leading or dominant over any other habitatM, M/SF, M/AF, M//SF, M//AF, SF, SF/M, SF/AF, SF//M, SF//AF, AF//, AF/

W/FW Wetlands/Moss−Seepage Forest Wetlands- wetlands; includes wetlands with fringe forests of moss or seepage forest

W,c W//M, W//SF, W//AF, W/M, W/SF, W/AF, M/W, SF/W, M//W, SF//W

LAKE Lake

a Forested Caribou Habitat Types are listed in descending order of caribou habitat value.b Site units comprising polygon units are described in Table 1. A single slash separating site units denotes approximately equal

proportions of each site unit making up the polygon; a double slash denotes that the first site unit is dominant over the secondc W = Non-forested wetland (NW) or forested wetland (FW).

FIGURE 2. Caribou use and availability of Caribou Habitat Types in the Tweedsmuir-Entiako caribouwinter range. Source: Cichowski (1989).


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TABLE 4. Summary of caribou habitat/forest cover overlay types found in the Tweedsmuir-Entiako caribouwinter range

Forest cover types/site classes

Lowa Poor Medium

Caribou habitat types Pine P/Sb Pine P/S Pine P/S Wetlands Lakes Other

DLLMc 1d 1 3 3 4 4 11 12 13

LM 1 1 3 3 4 4 11 12 13

DLLM MOSAIC 2 2 5 5 5 5 9 12 13

MDLLM 2 2 6 6 7 7 11 12 13

MSF/AF 2 2 6 6 8 8 11 12 13

WETLANDS 11 11 11 11 11 11 9 10 11

LAKES 12 12 12 12 12 12 12 10 12

Caribou habitat/forest cover overlay types Forested caribou habitat value Timber value

1 DLLM/LM on Low sites High Non-merchantable2 MDLLM/MOSAIC/MSFAF on Low sites Moderate-Low Non-merchantable3 DLLM/LM on Poor sites High Moderate-High4 DLLM/LM on Medium sites High High5 MOSAIC on Poor and Medium sites Moderate Moderate6 MDLLM/MSFAF on Poor sites Moderate-Low Moderate7 MDLLM on Medium sites Moderate-Low High8 MSF/AF on Medium sites Low High9 WETLANDS

10 LAKES11 Forest/Wetland Overlap12 Forest/Lake Overlap13 Other

a Site classes: Low = SI50 yr 0−7.9 m; Poor = SI50 yr 8.0−12.9 m; and Medium = SI50 yr 13.0+ m.b P/S = Pine/Spruce.c Caribou Habitat Types are described in Table 3.d Numbers in the table refer to caribou habitat/forest cover overlay types.


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4 TWEEDSMUIR-ENTIAKO CARIBOU WINTER RANGEMANAGEMENT STRATEGY

In the Tweedsmuir-Entiako area, a unique opportunity exists for developing a comprehensive managementstrategy for the caribou winter range. Information from an intensive study of caribou winter resourceselection is available, as is a reliable caribou winter habitat capability map. This information representssome of the best information we have on ungulate winter habitat capability and ungulate winter habitat usein British Columbia. The winter range management strategy is based on caribou winter resource selectionand on the caribou winter habitat capability map, and considers the potential direct and indirect impacts offorestry on the caribou population and on the winter range. Two levels of management planning areconsidered: a landscape level (Caribou Management Zones) in which large tracts of land are allocatedrelative values as caribou winter range, and a more site-specific level (caribou habitat/timber values) whichcompares conflicts between caribou habitat and timber values on specific sites.

The purpose of creating Caribou Management Zones was to stratify the study area into zonescharacterized by caribou habitat availability, historic use, and other values. Zoning provides the option toallocate different forest management strategies (management options) to different Caribou ManagementZones, depending on their value as winter range. Once forest management options are established, thecaribou habitat/timber value level can be used to develop harvesting regimes for specific stands within eachzone, and to locate merchantable timber stands where caribou habitat values are low. Six winter rangemanagement options are presented, based on the caribou habitat values in each of the 13 CaribouManagement Zones. These six options are described in Chapter 5. This chapter describes the proceduresused to delineate boundaries of Caribou Management Zones, the method proposed to identify sites forharvesting, a description of each Caribou Management Zone, and caribou habitat and timber supplycharacteristics for each zone.

4.1 Procedure for Delineating Caribou Management Zones

The caribou winter range was divided into Caribou Management Zones (CMZs) using the colour-themedcaribou habitat map, and 5 years of radio-collared caribou winter location data (1983/84 to 1987/88). Thecolour-themed map was used to identify areas of concentration of similar Caribou Habitat Types. CaribouManagement Zones were delineated based on the spatial distribution of those habitat types, and on radio-collared caribou locations within the winter range (Figure 3). Special winter range characteristics such asmigration corridors and late winter/early spring habitat were also considered. Each CMZ was rated as low,moderate, or high in terms of its value as caribou winter range. The CMZs containing large amounts of highvalue caribou habitat and used consistently during the five winter periods were classed as high valuezones. The CMZs with moderate amounts of high value habitat and moderate numbers of caribou winterlocations, or with special values, were classed as moderate value zones. The CMZs containing little highquality winter habitat and few radio-collared caribou winter locations were classed as low value zones.Relative values assigned to each CMZ allowed allocation of different forest management options to differentvalued zones.

Each zone was digitally over-laid onto the caribou habitat and the caribou habitat/forest cover overlaymaps. Databases from each of the 25 mapsheets were sorted for each TSA by CMZ. Caribou HabitatTypes, forest cover types, and caribou habitat/forest cover overlay types were then summarized for each CMZ.

4.2 Descriptions of Caribou Management Zones

The study area was delineated into 13 CMZs (Figure 4). The primary caribou winter range consisted of thearea south of Tetachuck Lake. Zone 11 therefore lies outside the primary winter range and was excludedfrom some of the analyses below.

Of the 13 CMZs, 2 were classified as high value winter range (4, 9); 7 were classified as moderatevalue winter range (2, 3, 6, 7, 10, 12, 13); and 4 were classified as low value winter range (1, 5, 8, 11) (Table5). Most of the caribou winter range within the Lakes TSA was classed as high or moderate value, whereas

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FIGURE 3. Radio-collared caribou locations during winter (December to April) from 1983/84 to 1987/88 the Tweedsmuir-Entiako caribou winter range.

FIGURE 4. Location of 13 Caribou Management Zones (solid lines) in the Tweedsmuir-Entiako caribouwinter range. Caribou winter habitat value is indicated by H - high, M - medium, and L - lowTimber Supply Area boundary is indicated by a dashed line.

.


11

most of the caribou winter range within the Prince George TSA was classed as low or moderate value. Inthe Prince George TSA, the most important caribou winter habitat occurred along the Entiako Riverdrainage. The core of the winter range, Zone 4, consists of most of the Entiako River drainage and is theCMZ most sensitive to disturbance. Zones 1, 5 and 8 in the periphery of the winter range contain primarilylow quality habitat and are the zones least sensitive to disturbance.

TABLE 5. Summary of Caribou Management Zones (CMZs) of the Tweedsmuir Entiako caribou winterrange

CMZArea Percent of Caribou winter

Special values(ha) study area habitat value

1 8 412 2.5 low2 14 329 4.2 moderate - late winter range3 12 475 3.7 moderate - migration corridor4 43 982 13.0 high - core winter range, migration corridor5 45 452 13.5 low6 5 467 1.6 moderate7 9 969 3.0 moderate8 18 697 5.5 low - adjacent to Tweedsmuir Park9 28 310 8.4 high - early winter/late winter range

10 11 300 3.4 moderate - late winter/early spring range11 59 786 17.7 low - spring migration route12 43 801 13.0 moderate - not mapped; alpine; mid-winter range; may be important

during deep snow or extreme crusty snow years13 35 554 10.5 moderate - Tweedsmuir Park; early winter range

Total area = 337 534 ha

In the following sections, the value of each CMZ as caribou winter range and the accompanying specialvalues are described. Tables 6−8 summarize the composition of each zone in terms of Caribou HabitatType, forest cover type, and caribou habitat/forest cover type. Raw data for Tables 6−8 are included inAppendix 2.

4.2.1 Caribou Management Zone 1

Caribou Management Zone 1 lies on the periphery of the primary caribou winter range, in thenortheastern corner of the study area. Some use of the western part of CMZ 1 occurs during latewinter (mid-March) when caribou concentrate near the mouth of the Entiako River; however, theoverall value of this zone as caribou winter range was classed low.


About half of the Tweedsmuir-Entiako herd uses CMZ 2 as late winter range (March), especially nearthe mouth of the Entiako River, and as a travel corridor from late winter range to the south shores ofTetachuck Lake, where they begin their spring migration (Table 9). Although CMZ 2 consists of littlehigh value caribou winter habitat (Table 6), during late winter while caribou use this area they appearto rely less on terrestrial lichens and more on vegetation found in snow-free areas and on arboreallichens (Cichowski 1989). Where terrestrial lichens do occur (primarily on eskers), foraging isextensive. The overall value of this zone as winter range is moderate and management in this zoneshould focus on maintaining or enhancing late winter forage, and maintaining a late winter travelcorridor. Because vascular plants appear to be a greater part of the diet of caribou while they use thiszone, timber harvesting will likely have fewer negative effects on their forage in this zone than in zoneswhere they are feeding primarily on lichens. Leaving buffer strips around eskers and other lichen-abundant areas may be important for maintaining a source of terrestrial lichens in the zone.

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TABLE 9. Percent of radio-collared caribou locations collected during five winters (1983/84 to 1987/88),occurring in each Caribou Management Zone (CMZ) during early winter (December to mid-January), mid-winter (mid-Janauary to mid-March), late winter (mid-late March), and April

Early winter Mid-winter Late winter April Total

CMZ % N % N % N % N % N

1 0.0 0 0.5 2 3.2 3 0.0 0 0.7 52 1.5 2 7.9 29 32.9 31 4.7 4 9.5 663 8.1 11 4.6 17 5.3 5 0.0 0 4.8 334 28.7 39 50.5 188 17.1 16 12.7 11 36.9 2545 11.7 16 7.8 29 1.1 1 2.3 2 7.0 486 14.0 19 4.8 18 0.0 0 0.0 0 5.4 377 0.0 0 0.5 2 0.0 0 0.0 0 0.3 28 2.2 3 1.4 5 0.0 0 0.0 0 1.2 89 19.1 26 9.4 35 1.1 1 34.9 30 13.4 92

10 2.2 3 3.5 13 20.2 19 26.7 23 8.4 5811 1.5 2 0.0 0 2.1 2 16.3 14 2.6 1812 2.9 4 8.3 31 17.0 16 1.2 1 7.6 5213 8.1 11 0.8 3 0.0 0 1.2 1 2.2 15

Total 100.0 136 100.0 372 100.0 94 100.0 86 100.0 688

N = Number of radio-collared caribou locations.


Caribou Management Zone 3 consists of three movement corridors and access to high elevation mid-winter range in the Fawnie Mountains. The Capoose Creek drainage (which separates Mt. Swannellfrom the rest of the Fawnie Mountains) provides one low elevation access route to late winter rangenear the mouth of the Entiako River. Two other unnamed drainages provide access routes to winterrange in the southeastern part of the study area. Access to subalpine and alpine habitat in the FawnieMountains is important during some years when up to 25% of the caribou move into the mountains inFebruary (Cichowski 1989). Zone 3 was classed as moderate value caribou winter range due to amoderate amount of good caribou winter habitat (Table 6) and the movement corridors. The focus ofmanagement in this zone should be to maintain continuous habitat along movement corridors, whichallows easy movement.


Zone 4 is one of the largest zones and is the core of the caribou winter range. Over 50% of the areaconsists of high quality caribou habitat (Dry Lichen−Lichen Moss, Lichen Moss) (Table 6) and it wasused consistently by radio-collared caribou during all five winters. Almost 40% of all radio-collaredcaribou winter locations occurred in this zone (Table 9). The Entiako River drainage is also amovement corridor for caribou during mid-winter when they start moving toward late winter rangenear the mouth of the Entiako River. Zone 4 is the most important zone for caribou winter range in thestudy area. Because of its significance to the caribou population, the focus of management in thiszone should be on the maintenance of high value caribou habitat — that is, no logging activity orroads. The potential direct effects (destruction of food source) and indirect effects (increased distur-bance due to increased access, increased quality of moose habitat, and altered predator-preyrelationships) associated with timber harvesting may further accelerate the present population declineif the core of the caribou winter range is disturbed. For long-term management, a fire managementplan should be developed to ensure periodic natural disturbance (100−200 years) for terrestrial lichenregeneration.


Zone 5 is located in the southeastern part of the study area, and is the largest zone in the primarywinter range. Although this zone contains little high quality caribou habitat (Table 6), some use by


17

radio-collared caribou occurred throughout the zone during all five winters (Table 9). Occasionally,caribou have also been found in areas south or southeast of the study area, adjacent to this zone.Although the overall rating for the zone is low, it supports some capacity for caribou winter range andprovides access to outlying areas and to CMZ 6. Timber harvesting has already occurred in thesoutheastern part of this zone.


Zone 6 is encircled by CMZ 5, and consists of the best caribou habitat available in the southeasternpart of the winter range. This zone was used heavily by radio-collared caribou in the winter of 1984/85,and to a lesser extent in 1983/84 and 1986/87. Part of this zone has also already been logged.Overall, Zone 6 was rated as moderate value caribou winter range due to historic caribou use patternsand because it consisted of the only block of good quality caribou winter habitat in the southeasternpart of the winter range.


Zone 7 consists primarily of high quality caribou habitat, but it contains few radio-collared cariboulocations (Table 9). Much of the Lichen Moss and all of the Dry Lichen−Lichen Moss habitat iscurrently immature and has likely not achieved its maximum capability as caribou winter habitat. Zone7 was classified as moderate value caribou winter range based on its potential caribou habitatcapability.


Zone 8 is located adjacent to the eastern boundary of Tweedsmuir Park. This zone was rated as lowvalue caribou winter range because it contains little high quality caribou habitat and few radio-collaredcaribou locations (mostly early winter locations). A somewhat deeper snowpack during winter likelylimits its potential as caribou winter range. Although it was rated as low value winter range, itsproximity to Tweedsmuir Park may warrant special management considerations.


Zone 9 consists primarily of high quality caribou habitat. It was used by caribou consistently during allfive winters of radio-tracking. This zone is most heavily used by caribou in early winter (November tomid-January) when they first reach the winter range after fall migration, and during late winter/earlyspring (late March/April) when they concentrate at the south side of Tetachuck Lake before crossingthe lake for spring migration in May (Table 9). Caribou also used CMZ 9 to a lesser extent throughoutthe winter, but it was not considered to be part of the core of the winter range. Overall, Zone 9 wasrated as high value caribou winter range and management should focus on maintaining the zone forhigh value caribou habitat.


Zone 10 contains a moderate amount of high quality winter habitat. It was most heavily used bycaribou in late winter/early spring, just before they crossed Tetachuck Lake during spring migration.The Tetachuck River at the east end of the lake is the first to become free of ice and is likely wheremany caribou cross. Overall, Zone 10 was rated as moderate value caribou winter range because ofits importance during late winter/early spring and its role in spring migration.


Although CMZ 11 contains a moderate amount of high quality caribou winter habitat, it lies outside theprimary caribou winter range. It was rated as low value caribou winter range due to its location, but it isvery important in terms of spring migration. Although this zone was not used by caribou during thewinter resource selection study, several radio-collared caribou were found in this zone during March1991 (B.C. Environment, unpubl. data). Because those caribou had not been found since November


18

1990, it was unknown whether they had wintered in the area or moved there in late winter. Amanagement plan for the spring migration corridor on the north side of Tetachuck Lake is currentlybeing developed (Chelaslie Caribou Spring Migration Corridor Plan) and will not be discussed in thisreport.


Zone 12 consists of all the area made up of the Engelmann Spruce−Subalpine Fir (ESSF) and AlpineTundra (AT) Biogeoclimatic Zones, within or adjacent to the Fawnie Mountains. Habitat mapping wasnot done in CMZ 12 because, except for windswept slopes in the alpine, snow depth at thoseelevations limits the availability of terrestrial forages for use by caribou during the winter. During someyears, up to 25% of the radio-collared caribou used subalpine or alpine habitat in the FawnieMountains, from mid-February to mid-March (Cichowski 1989). Marshall (1985) observed 368 caribouin the Fawnie Mountains in mid-March 1982, before the radio-collared caribou study. This zone wasalso heavily used by radio-collared caribou during a reconnaissance flight in early March 1991 (B.C.Environment, Fish and Wildlife Branch, unpubl. data). Snow conditions appeared to be deeper andcrustier that year than during the study.

In alpine habitat, caribou feed on terrestrial forages (lichen, gramminoids); in subalpine habitat,caribou feed on arboreal lichens. The most heavily used areas include alpine habitat on Mt. Swannelland Tutiai Mountain, all subalpine habitat on Mt. Swannell, and subalpine habitat on the east side ofthe Fawnie Range (primarily on the Fawnie Plateau).

Zone 12 was considered low value caribou winter range in terms of terrestrial lichen foraging;however, during late winter or during winters of deep or severely crusted snow at lower elevations,caribou may switch from feeding on terrestrial lichens at low elevations to feeding on arboreal lichensin subalpine habitat. Overall, CMZ 12 was rated as moderate caribou winter range because of itspotential role during adverse snow conditions. Timber harvesting in this zone should be avoided inthose areas most frequently used by caribou.


Zone 13 lies entirely within Tweedsmuir Park. Although the area contains a moderate amount of highquality habitat, the capability of this zone as caribou winter habitat is likely limited by snow accumula-tion. Most of the caribou use within this zone occurred during early winter (Table 9). Overall, this zonewas rated as moderate for caribou winter range capability. Because CMZ 13 is protected by Class APark status, it was excluded from the timber analysis.

4.3 Caribou Habitat/Timber Values

Within each CMZ, site-specific caribou habitat and timber values were compared using the colour-themedcaribou habitat/forest cover overlay map. The matrix in Table 4 identifies caribou habitat/forest cover typesof low potential conflict (low timber value, high caribou habitat value) and high potential conflict (highcaribou habitat value, high timber value). The caribou habitat/forest cover overlay map can be used toidentify those sites within CMZs where harvesting merchantable quality timber will have the least impact oncaribou winter habitat.

Because each Caribou Habitat Type consisted of several site units, polygon labels on the caribouhabitat map can be used to further divide Caribou Habitat Types in terms of caribou habitat values. Table 10presents possible combinations of site units within Caribou Habitat Types in descending order of value ascaribou habitat. Consequently, a harvesting plan that considers both Caribou Habitat Types and caribouhabitat/forest cover overlay types can be developed for each CMZ.


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TABLE 10. Possible site unit combinations of forested caribou habitat site units, in descending order ofcaribou habitat value, in the Tweedsmuir-Entiako caribou winter range

Caribou Habitat Type

DLLM LM DLLM MOSAIC MDLLM MSF/AF

DLa LM DL//W M/DL MDL//LM LM//M DL//SF M/LM M//SFDL/LM LM/M LM//W M/SF/DL M//AFDL//M LM//SF SF/M/DL M/SFLM/DL DL/W M/SF/LM M/AFLM//DL DL/SF SF/M/LM SF/MDL/M LM/W M//DL SF//M

LM/SF M//LM SFW/DL M/SF//DL SF//AFSF/DL SF/M//DL SF/AFW/LM M/SF//LM AF//SF/LM SF/M//LM AF/W//DL M//SF/DLSF//DL SF//M/DLW//LM M//SF/LMSF//LM SF//M/LM

M//SF//DLM//SF//LMSF//M//DLSF//M//LM

a Site units are described in Table 1 (W = forested and non-forested wetlands; NW and FW). A single slash separating site unitsdenotes approximately equal proportions of each making up the polygon; a double slash denotes that the first unit is dominant overthe second.

4.4 Timber Supply Characteristics

4.4.1 Methods

The forest cover database was used to summarize timber supply characteristics by Caribou HabitatType for each CMZ in each TSA. The gross land base was netted down by criteria described in Table 11to determine the net land base. The net land base excludes primarily non-forest land and non-mer-chantable timber. The net land base, the total area netted down, the volume of timber (after netdowns) and the Long Run Sustained Yield (LRSY) (after net downs) in each CMZ were summarizedby each Caribou Habitat Type.

For the Prince George TSA, volume was calculated using the following criteria:

SpeciesPriority age Utilization levels

(years) (minimum dbh [cm])

Pine >100 12.5Spruce >140 15.0Balsam >120 17.5

For the Lakes TSA, volume was calculated using the following criteria:

SpeciesCulmination age Utilization levels

(Years) (minimum dbh [cm])

Pine >80 15.0Spruce >120 17.5Balsam >120 17.5


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TABLE 11. Reductions (net downs) applied to the total land base for the Lakes and Prince George TimberSupply Areas, in the Tweedsmuir-Entiako caribou winter range

Reduction Prince George Lakes

Non-forest land- type identitya ID) = 6 x x

Non-stocked land- not sufficiently restocked (ID = 4) x x- non-commercial (ID = 5) x x- DSD (ID=7) x

Environmentally Sensitive Areasa (ESA)- all x- partial net downsb x

Low site typesa x x

Deciduous forest types- inventory type groupsa 35−42 x x

Mature height class 2a x

Mature problem forest types- partial net downsb x

Other reductions- immature residual (ID=3) x x- inventory type group 27 x x- inventory type group 31 x- stocking class 4,a pine forest types

(inventory type groups 28−30) x x- projected age class 9, balsam forest types

(inventory type groups 18−20) x- volume <140 m3/ha and projected age >200 years x- volume <140 m3/ha and: x

projected age classa >5, balsam types (18−20);projected age class >5, spruce types (21−26);projected age class >4, pine types (28−31);

- immature problem forest types- partial net downs x

a Type identities, inventory type groups, Environmentally Sensitive Areas, site class, height class, stocking class, and age class aredescribed in B.C. Ministry of Forests 1990.

b Area inclusion factors for Environmentally Sensitive Areas, mature problem forest types, and immature problem forest types arespecified in Appendix 3.

Because volumes for utilization of timber to a 15.0 cm diameter were not available in thedatabase, the volume for utilization of timber to 15.0 cm was calculated by averaging the volumes forutilization to 12.5 and 17.5 cm.

Utilization levels used in this report for the Lakes TSA differ from current utilization levels sinceTSA summary information was not available for the current levels. Therefore, utilization levels fromthe most recent TSA report (B.C. Ministry of Forests 1985) were used. Current utilization levels (min.dbh) in the Lakes TSA are: pine - 12.5 cm; spruce - 15.0 cm; and balsam - 17.5 cm. Volumes (after netdowns) for each Caribou Habitat Type in CMZs for the Lakes TSA using the new utilization levels areincluded in Appendix 4.

The LRSY estimate was calculated by multiplying the area of each caribou habitat/forest coveroverlay polygon by the average mean annual increment (MAI) for the analysis unit (timber type andsite class combination) of that polygon. The MAI estimates were based on the same utilization levelsused for calculating volumes. Average MAI for each analysis unit was calculated using the B.C.Ministry of Forests YIELD program (B.C. Ministry of Forests 1988). Average MAI estimates (in m3/ha⋅yr-1)


21

used in the Prince George and Lakes TSAs are given in Appendix 5. For the Lakes TSA, the LRSYestimated for each CMZ using the new utilization levels is included in Appendix 4.

4.4.2 Timber supply characteristics

Timber supply characteristics of each CMZ were calculated using the forest cover databases over-layed with the caribou habitat database. Reductions (net downs) to the total land base, by net downtype (see Table 11), are presented in Table 12. Between 16 and 74% of the total area of individualCMZs, and almost 50% of the total study area were netted down. Most of the netted down areaconsisted of non-forest types (lakes), timber on low site types, height class 2 stands (Lakes TSA),mature problem types (Prince George TSA), and environmentally sensitive areas (Tables 12, 13).

Net land base, volume (after reductions), and the LRSY estimate (after reductions) in each CMZby Caribou Habitat Type are presented in Tables 14−16, respectively.

High value CMZ’s (4,9) consist of primarily Dry Lichen−Lichen Moss (DLLM) and Lichen Moss(LM) Caribou Habitat Types, whereas low value zones (1, 5, 8, 11) consist primarily of Moss/DryLichen−Lichen Moss (MDLLM) and Moss−Seepage Forest/Aspen Forest (MSF/AF) Caribou HabitatTypes (Table 14). The percent of the LRSY estimate for each Caribou Habitat Type was almostidentical to the percent of the net land base in each Caribou Habitat Type. The percent of the netvolume was also similar to the percent of the net land base for each Caribou Habitat Type. Raw datafor Tables 12−16 are included in Appendix 2.

All CMZs (excluding CMZ 11) were combined for each TSA, and the percent of each caribouhabitat in the total area, total land base, the net down area, the net land base, and the volume andLRSY estimate on the net land base was calculated for each TSA (Tables 17, 18). In the Lakes TSA,over 35% of the net land base, volume, and LRSY consisted of high value Caribou Habitat Types (DryLichen−Lichen Moss and Lichen Moss), whereas in the Prince George TSA, less than 25% of the netland base, volume, and LRSY consists of high value Caribou Habitat Types. The Lakes TSAcontained both high value CMZs (9, one-half of 4); the Prince George TSA was made up primarily oflow value and some moderate value CMZs. Management options focusing on maintaining caribouhabitat in high value zones will have a greater impact on the Lakes TSA than on the Prince George TSA.


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5 MANAGEMENT OPTIONS

The management strategy introduced in Chapter 4 encompasses two planning levels. Planning is first doneat the CMZ level by prescribing different timber harvesting strategies for specific CMZs. Within a zone,timber harvest planning is done at a site-specific level by restricting timber harvesting to specific CaribouHabitat Types or site units. With both levels of management used in combination, a timber harvestingstrategy can be developed for the winter range which minimizes the potential direct and indirect effects oflogging on the caribou winter range and on the caribou population. Clearly, many options are possible; inthis chapter, we define six potential management options and address the implications of those options onthe caribou population and the timber supply.

5.1 Management Options

The six management options ranged from an emphasis on caribou in Option 1 (no timber harvesting in thewinter range) to an emphasis on timber harvesting in Option 6 (moderate level of harvesting intensitythroughout the entire winter range) (Table 19). A common element to the first four options was theprotection of the core of the winter range, CMZ 4. That element was perceived as the absolute minimummanagement standard for caribou, due to the potential direct and indirect effects of logging on the cariboupopulation. The first four options vary primarily in the number of CMZs allocated for harvesting. Options 5and 6 allow for some intensity of timber harvesting in all zones. In Option 6, the CMZ classification systemwas ignored; that is, the same harvesting regime was applied in each zone, regardless of its value. Thatoption was included to assess the consequences of considering only direct impacts of logging on caribou(by protecting high value caribou winter habitat throughout the winter range) and not considering indirecteffects.

TABLE 19. Management options for the Tweedsmuir-Entiako caribou winter range

1. No harvesting.

2. No harvesting in CMZ 2, 4, 9, 10.- Other moderate value zones: harvest in MSF/AF, MDLLM, ESSF- Low value zones: harvest in MSF/AF, MDLLM, ESSF

3. No harvesting in CMZ 4, 9.- Moderate value zones: harvest in MSF/AF, MDLLM, ESSF- Low value zones: harvest in MSF/AF, MDLLM, ESSF

4. No harvesting in CMZ 4.- Other high value zones (CMZ 9): harvest in MSF/AF, ESSF- Moderate value zones: harvest in MSF/AF, MDLLM, ESSF- Low value zones: harvest in MSF/AF, MDLLM, ESSF

5. Restricted harvesting.- High value zones: harvest in MSF/AF, ESSF- Moderate value zones: harvest in MSF/AF, MDLLM, ESSF- Low value zones: harvest in all habitat types

6. Restricted harvesting.- All zones: harvest in MSF/AF, MDLLM, ESSF

5.2 Implications to the Tweedsmuir-Entiako Caribou Population

If the sole objective for this area was to maintain the caribou population at its present level, Option 1 wouldbe the most appropriate option to implement. By restricting timber harvesting from the entire winter range,the negative direct and indirect effects that logging may have on the caribou population would be avoided.To maintain at least some level of timber harvest in the study area, one of Options 2−6 should be selected.Each successive management option allows for a greater level of harvesting in the winter range and thuswill result in progressively increasing impacts on the caribou population. Option 6 would have the greatest


27

potential negative impacts on the caribou population, since harvesting is distributed throughout the entirewinter range. Increased disturbance through increased access, decreased space, and altered predator/prey relationships would occur throughout the entire winter range instead of being concentrated in low andmoderate value zones as in Options 2−5.

5.3 Implications to the Timber Supply

Implications of each management option to the timber supply were assessed by examining the effects ofeach management option on the total area, net land base, net volume, and LRSY in each TSA (Tables 20and 21).

In the Lakes TSA, the impact of each management option on the TSA was reduced with eachsuccessive management option because of minor changes in harvesting intensity in the high and moderatevalue CMZs, and because most of the caribou winter range in the Lakes TSA consists of moderate and highvalue zones (Table 20).

In the Prince George TSA, the impact of Option 2 on the timber supply was substantially less than theimpact of Option 1 on the timber supply (Tables 21 and 22). Because much of the caribou winter range inthe Prince George TSA is of low or moderate value, increasing harvesting from zero (Option 1) to amoderate level of intensity (Option 2) results in a significant change to impacts on the total and net landbase, net volume, and LRSY. Successive options resulted in little change to the reductions calculated forOption 2. The effects of Option 3 and Option 4 on the Prince George TSA were identical since the differencebetween the two options was the inclusion of low intensity harvesting in Zone 9, which lies entirely within theLakes TSA. Option 6, which ignores the CMZ concept, results in reductions similar to those of Options 3and 4 for the Prince George TSA. Although Options 3, 4, and 6 are similar in their impacts on the timbersupply, Option 6 would have greater negative effects on the caribou population than would either Option 3or Option 4.

5.3.1 Short-term effects on timber supply

The short-term effects on the timber supply were addressed by examining the effects of managementoptions on the volume of priority age timber in the Prince George TSA, and the volume of culminationage timber in the Lakes TSA. In the Lakes TSA, Option 1 resulted in a 5.9% reduction to the volume(after net downs) (Table 20). Each successive management option resulted in further volume reduc-tions to 2.5% in Option 6. In the Prince George TSA, the reduction to the net volume dropped from 2.1to 0.5% from Option 1 to Option 2, and 10.0 to 2.6% in the Vanderhoof Supply Block (Table 21).Impacts on the net volume varied little from Options 2 to 6 in the Prince George TSA (0.5 to 0.4%) or inthe Vanderhoof Supply Block (2.6 to 1.8%).

5.3.2 Long-term effects on timber supply

The long-term effects on the timber supply were addressed by examining the effects of managementoptions on reductions to the LRSY. In the Lakes TSA, Option 1 resulted in a 4.7% reduction to theLRSY, a 6.6% reduction to the net land base, and a 6.5% reduction to the total land base (Table 20).The largest difference between subsequent options occurred between Option 2 and Option 3 as aresult of including a moderate level of harvesting intensity in CMZs 2 and 10. In the Prince GeorgeTSA, the effects of management options on the LRSY were similar to the effects on the short-termtimber supply (Table 21). Option 1 resulted in a 1.9% reduction to the LRSY for the TSA, a 2.6%reduction to the net land base, and a 2.2% reduction to the total land base. For the Vanderhoof SupplyBlock, Option 1 resulted in a 9.8% reduction to the LRSY, a 11.7% reduction to the net land base, anda 12.9% reduction to the total land base. The impact of Option 2 to the LRSY was 41% of the impact ofOption 1 (Table 22). The impacts of Options 3 to 6 on the LRSY of the Prince George TSA variedbetween 30 and 40% of the impact of Option 1. Options 3 to 6 had similar effects on the Prince GeorgeTSA and Vanderhoof Supply Block as did Option 2.


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TABLE 20. Effects of management options for the Tweedsmuir-Entiako caribou winter range on the LakesTimber Supply Area

LAKES TSA

Total land base: 1 123 162 haNet land base: 601 000 haVolume (after net downs): 94 000 000 m3

LRSY (after net downs): 1 120 000 m3/yr

Reduction to Reduction to Reduction to Reduction toTotal land base Net land base volume LRSY

Options% ha % ha % m3 % m3/yr

1 6.5 72 641 6.6 39 412 5.9 5 584 213 4.7 52 3172 6.1 68 052 6.4 38 587 5.7 5 362 509 4.5 50 9113 4.8 53 305 4.5 27 246 3.4 3 158 476 3.0 33 8674 4.4 48 987 4.0 23 890 3.0 2 851 951 2.6 28 7085 4.1 45 960 3.9 23 763 2.9 2 684 480 2.5 27 5766 3.9 43 201 3.5 21 311 2.5 2 387 692 2.2 24 933

TABLE 21. Effects of management options for the Tweedsmuir-Entiako caribou winter range on the PrinceGeorge Timber Supply Area and Vanderhoof Supply Block

PRINCE GEORGE TSA

Total land base: 7 581 200 haNet land base: 3 147 000 haVolume (after net downs): 498 164 000 m3




1 2.2 169 898 2.6 81 856 2.1 10 191 204 1.9 152 1842 0.9 65 052 1.0 31 477 0.5 2 675 825 0.8 62 1973 0.8 62 651 1.0 30 064 0.5 2 411 832 0.8 59 1384 0.8 62 651 1.0 30 064 0.5 2 411 832 0.8 59 1385 0.6 44 269 0.7 23 254 0.4 1 833 001 0.6 46 6506 0.7 53 488 0.9 27 180 0.4 2 072 279 0.7 53 771

VANDERHOOF SUPPLY BLOCK

Total land base: 1 318 300 haNet land base: 700 000 haVolume (after net downs): 101 874 000 m3




1 12.9 169 898 11.7 81 856 10.0 10 191 204 9.8 152 1842 4.9 65 052 4.5 31 477 2.6 2 675 825 4.0 62 1973 4.8 62 651 4.3 30 064 2.4 2 411 832 3.8 59 1384 4.8 62 651 4.3 30 064 2.4 2 411 832 3.8 59 1385 3.4 44 269 3.3 23 254 1.8 1 833 001 3.0 46 6506 4.1 53 488 3.9 27 180 2.0 2 072 279 3.4 53 771


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TABLE 22. Relative effects of management options (% of Option 1) for the Tweedsmuir-Entiako caribouwinter range on the Lakes and Prince George Timber Supply Areas

LAKES TSA

Relative reduction Relative reduction Relative reductionto land base to volume to LRSY

Options% ha % m3 % m3/yr

1 100.0 39 412 100.0 5 584 213 100.0 52 3172 97.9 38 587 96.0 5 362 509 97.3 50 9113 69.1 27 246 56.6 3 158 476 64.7 33 8674 60.6 23 890 51.1 2 851 951 54.9 28 7085 60.3 23 763 48.1 2 684 480 52.7 27 5766 54.1 21 311 42.8 2 387 692 47.7 24 933

PRINCE GEORGE TSA

Relative reduction Relative reduction Relative reductionto land base to volume to LRSY

Options% ha % m3 % m3/yr

1 100.0 81 856 100.0 10 101 204 100.0 152 1842 38.5 31 477 26.3 2 675 825 40.9 62 1973 36.7 30 064 23.9 2 411 832 38.9 59 1384 36.7 30 064 23.9 2 411 832 38.9 59 1385 28.4 23 254 18.2 1 833 001 30.7 46 6506 33.2 27 180 20.5 2 072 279 35.3 53 771

6 DISCUSSION

6.1 Management Strategy for the Tweedsmuir-Entiako Caribou Winter Range

The management strategy for the Tweedsmuir-Entiako caribou winter range presented in this report is adual level approach to managing winter ranges of terrestrial lichen feeding woodland caribou. At thelandscape level, information on caribou winter resource selection was integrated with a reliable ecosystemmap of the caribou winter range, to develop CMZs. For woodland caribou, a landscape approach tomanagement is essential because habitat fragmentation due to logging may result in both direct andindirect effects on the population. Logging may directly affect the caribou population through destruction ofterrestrial lichens, the primary caribou winter food source. Logging may indirectly affect the cariboupopulation by increasing such human disturbance as hunting and poaching, through increased access, andby altering predator-prey relationships. By partitioning the winter range into zones of low, moderate, andhigh caribou winter range value, the most valuable can be given maximum protection while areas with lowervalues can be given less protection. At the site-specific level, information from the habitat map can be usedto develop a harvesting strategy for the low to moderate value zones.

Two other studies have suggested management strategies for winter ranges of terrestrial lichenfeeding woodland caribou. In west-central Alberta, the primary objective of management was to maintainan adequate amount of preferred caribou habitat (Edmonds and Bloomfield 1984). Because almost 90% ofcaribou foraging in openings occurred less than 50 m from cover, Edmonds and Bloomfield (1984)suggested that cutblocks be narrow strips with widths no greater than 150 m. However, since that time,caribou biologists have become increasingly concerned that small cutblocks excessively fragment habitat,


30

which can result in increased predation on caribou. Recommendations on cutblock size and shape inAlberta have been changed to accommodate the effects of creating abundant edge habitat favoured bymoose (J. Edmonds, pers. comm.).

In Ontario, the Northwestern Ontario Forest Ecosystem Classification (NWO FEC) was found to be anadequate descriptor of caribou range features, particularly of soil and vegetation characteristics (Morashand Racey 1989). That information, together with information on caribou habitat requirements, was used todevelop timber management guidelines for the provision of caribou habitat in northwestern Ontario (OntarioMinistry of Natural Resources, 1990). Management of suitable winter habitat, identified using the NWOFEC, was suggested for blocks of land as large as possible (combinations of blocks 10 × 10 km). Harvestingactivities were to be concentrated in areas based on 10 × 10 km blocks to maintain contiguous tracts ofwinter habitat. Also suggested were provisions for immediately removing forest access roads in and nearhigh quality caribou winter habitat once timber management operations ceased, and for discouragingregeneration of logged sites to habitat suitable for moose or deer.

The timber management guidelines developed in Ontario for woodland caribou habitat are similar tothe management strategy discussed in this report. Both are based on a landscape approach to caribouwinter habitat management, and both identify areas (zones) of important potential caribou winter habitat. Innorthern Ontario, however, caribou populations and caribou winter habitat occur in a relatively contiguousdistribution and timber management guidelines are applied at a much larger scale than in British Columbia.In southern and central British Columbia, caribou populations and caribou winter ranges are more discretethan those in Ontario. Caribou winter habitat management strategies are therefore more appropriate on aherd-specific basis. We believe that the method used to develop the management strategy for theTweedsmuir-Entiako woodland caribou winter range would also be applicable for developing managementstrategies for other discrete populations of woodland caribou in British Columbia that rely on terrestriallichens during winter. Currently, a management strategy based on the Tweedsmuir-Entiako study is beingdeveloped for the Itcha-Ilgachuz caribou winter range in west-central British Columbia.

6.2 Management Options for the Tweedsmuir-Entiako Caribou Winter Range

Because most of the caribou populations in southern and central British Columbia have significantlydeclined in numbers and in range in the past 100 years (Stevenson and Hatler 1985), maintenance ofcaribou populations where they still occur in relative abundance is critical to the survival of woodlandcaribou in the southern half of British Columbia.

Stevenson and Hatler (1985) identified the Tweedsmuir-Entiako area as one of the high prioritymanagement areas for caribou in southern and central British Columbia. Maintenance of winter rangecharacteristics is an essential objective in the overall management of the Tweedsmuir-Entiako cariboupopulation. Currently the population appears to be declining5 and the potential indirect effects of currentlogging practices on woodland caribou in the area (increased human disturbance, increased predatorefficiency, altered predator-prey relationships) may further contribute to that decline. Therefore, in theTweedsmuir-Entiako caribou winter range, forest harvesting must be compatible with caribou populationand habitat objectives.

Caribou population and habitat objectives would be best achieved through implementation of Option 1.In the long run, that option would result in a 4.7% reduction to the LRSY of the Lakes TSA, and a 1.9 and9.8% reduction to the LRSY of the Prince George TSA and Vanderhoof Supply Block, respectively. Option 2reduces that impact to a 4.5% reduction in the Lakes TSA and a 0.8 and 4.0% reduction to the LRSY of thePrince George TSA and Vanderhoof Supply Block. In the short run, Option 1 results in volume reductions of5.9% to the Lakes TSA, 2.1% to the Prince George TSA, and 10.0% to the Vanderhoof Supply Block.Option 2 reduces the short-term impacts of Option 1 on volume by 4% in the Lakes TSA and by 74%

5 Cichowski [1993].


31

in the Prince George TSA. In Option 2, logging is restricted to low value CMZs in the periphery of the winterrange. Because the Lakes TSA consists of high and moderate value CMZs, and the Prince George TSAconsists of primarily low and moderate CMZs, the impact of Option 2 is lower on the Prince George TSAthan on the Lakes TSA.

Subsequent options increase the amount of harvesting in moderate and high value zones. Options3−6 have similar effects on the LRSY of the Prince George TSA as Option 2, and have progressivelyreduced impacts on the Lakes TSA; however, they also have progressively increased impacts on thecaribou population. Option 6, which allows harvesting of low value caribou habitat in all zones, has similarimpacts on the LSRY of Prince George TSA as do Options 3 and 4. The resulting fragmentation of theTweedsmuir-Entiako caribou winter range associated with Option 6 would likely have far greater impacts onthe population than either Option 3 or 4.

Some reduction of the timber supply in both the Prince George and Lakes TSAs is necessary tomaintain caribou winter range requirements. At a minimum, if caribou are to have a reasonable chance ofsurviving in the area, harvesting should not be permitted in at least the core of the winter range (Option 4).However, protecting additional areas (Option 4 to Option 1) would further improve the chances of survival.Option 2 will likely have greater impacts on the caribou population and winter range than Option 1 (noharvesting), but we feel that Option 2 would best integrate timber harvesting with maintenance of caribouwinter range.

Option 2 allows some timber harvesting in all zones except zones 2, 4, 9 and 10. Within CMZs whereharvesting is permitted, harvesting practices must consider potential indirect effects of timber harvesting oncaribou, and the special characteristics of that zone. Because caribou use the area in the winter, harvestingduring winter months should be concentrated in one area and in the periphery of the winter range to reduceany potential direct disturbance to the caribou. To partially mimic the fire history of the area, and to reducethe value as winter habitat for moose, cutblocks should be 200−300 ha in size, but with unharvestedpatches or stringers of mature timber retained along water courses, around wetlands, and within Dry Lichenand Lichen-Moss site units. Mature leave areas between cutblocks should be at least as large as thecutblocks and there should be a minimum of 25 years between harvesting passes. Silvicultural practicesreducing the amount of shrubby forage available for moose in cutover areas are also encouraged (mostsites are expected to have fairly low potential for post-harvest shrub development). However, reducingstocking densities early in the life of the stand should encourage earlier lichen colonization. In zonesdesignated as travel corridors, shape and orientation of cutblocks should maximize the amount of contig-uous movement habitat in the direction of travel. For example, in CMZ 3, cutblocks should be rectangular,with the long side of the block oriented parallel to Capoose Creek. Access into the winter range on forestaccess roads by all vehicles (including snowmobiles) should be prohibited during winter. Forest accessroads within 10 km of the core of the winter range should be scarified and rehabilitated as soon as possibleafter harvesting has ceased. In addition, harvesting techniques that reduce disturbance to terrestrial lichenpopulations, such as winter logging, are encouraged. Further research into harvesting techniques thatminimize disturbance to terrestrial lichens and that accelerate regeneration of terrestrial lichens is recom-mended. Currently, the B.C. Ministry of Forests in Williams Lake is researching such techniques in theItcha-Ilgachuz caribou winter range (H. Armleder, pers. comm.).

6.3 Further Information Needs

6.3.1 Forest inventory

The information used to determine impacts of caribou management options on the timber supply wasbased on forest cover mapping and inventory data. The accuracy of those data in the Tweedsmuir-Entiako area is likely less than in other areas because very little ground-truthing was conducted tosupplement the aerial photo interpretation in the preparation of the forest cover maps. The caribouhabitat ecosystem maps are likely a better predictor of forest productivity than are the forest covermaps for that area, since extensive ground-truthing was conducted to produce the habitat maps. TheLakes District is updating the forest inventory information for the Tweedsmuir-Entiako area, and aspart of that update, information from the caribou habitat map is being used. Some of the forest


32

inventory that was previously classed as merchantable will likely be reclassified as non-merchantable.Assessment of the impacts of management options using the updated information would result in amore accurate evaluation of those impacts, and likely indicate that reductions to the timber supply dueto caribou habitat protection are less than current forest inventory information suggests.

6.3.2 Tweedsmuir-Entiako caribou

Some aspects of Tweedsmuir-Entiako woodland caribou ecology still need to be addressed. In latewinter, caribou move to ranges near the mouth of the Entiako River. Food habits of caribou at that timeof year are not well understood. There is little habitat containing abundant terrestrial lichens. Itappears that they may switch from feeding on terrestrial lichens to feeding on arboreal lichens orvegetation in snow-free areas. A better understanding of forage selection during late winter willfacilitate defining harvesting guidelines compatible with late winter range.

Terrestrial lichen stands begin declining over the long run (200−300 years) as feathermossescolonize the forest floor, and they must undergo periodic disturbance to regenerate back to productivestands. In the past, wildfires acted as a disturbance factor. Today, however, with widespread firesuppression efforts, occurrence of wildfires has been significantly reduced. Eventually terrestriallichen sites in high value CMZs must be regenerated back to productive levels. Further research intoregenerating terrestrial lichen stands while minimizing potential impacts to the caribou population isalso required and a Fire Management Plan for the winter range should be developed.

Although arboreal lichens are used less than terrestrial lichens on the low elevation winter range,arboreal lichens are a secondary food source during winter. Where possible, both terrestrial andarboreal lichens should be maintained. The caribou winter habitat map shows terrestrial lichenabundance only. Methodology should be developed to predict arboreal lichen abundance and used inconjunction with the caribou habitat map.

Because the Tweedsmuir-Entiako caribou population is declining, a management strategy for thecaribou winter range must address caribou population considerations in the short run, as well ascaribou population and habitat considerations in the long run. Further research is required to deter-mine the primary limiting factor causing the population decline. Once the cause of the decline isknown, wildlife management techniques may be employed to stop the declining population trend. Abetter understanding of the population limiting factor will also result in a better understanding ofpotential indirect effects of timber harvesting on the Tweedsmuir-Entiako caribou winter range.Harvesting guidelines could be further refined to maximize caribou habitat and timber harvestingpotential.

7 RECOMMENDATIONS

1. At a minimum, timber harvesting should be prohibited in CMZ 4, the core of the winter range. Option 2will result in the least potential negative impacts of timber harvesting on the Tweedsmuir-Entiakocaribou population and winter range, without restricting harvesting from the winter range completely(Option 1).

2. Updated forest inventory data should be used to reassess the implications of Tweedsmuir-Entiakocaribou winter range management options on the timber supply.

3. In CMZs where logging is permitted, cutblocks should be 200−300 ha in size, and cutblock shapeand orientation should reflect special considerations within zones. Cutblocks should be carefullylaid out to maintain within them several patches or stringers of forest along streams, aroundwetlands, and in selected pine stands containing terrestrial lichens. Access to the winter range onforest access roads should be prohibited.


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4. Investigations of forage selection during late winter in CMZ 2 should be undertaken. A betterunderstanding of forage selection in that zone would facilitate the defining of harvesting guidelinesthat are compatible with late winter range.

5. The primary limiting factor of the Tweedsmuir-Entiako caribou population should be determined,and management techniques stopping the current population trend should be implemented.

6. Research should be undertaken into timber harvesting methods that minimize disturbance toterrestrial lichen stands, and into accelerated regeneration of terrestrial lichens after forestharvesting.

7. Monitoring of caribou movements and habitat use in relation to first pass cutblock patterns shouldbe conducted and used to guide and modify future development within the winter range.

8. A method for predicting arboreal lichen abundance should be developed and used in conjunctionwith the caribou habitat map.

SEQ 5180 JOB LMR83-017-010 PAGE-0034 APP 1 & TAB A2.1REVISED 15JUN00 AT 06:38 BY BC DEPTH: 60 PICAS WIDTH 42.09 PICAS COLOR LEVEL 1

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APPENDIX 1. Relationships between site units defined in this report and Biogeo-climatic Ecosystem Classification (BEC) site units defined for theSBPSmc and SBSdka

Site units used SBPSmc Site Series SBSdk Site Seriesin this report number and nameb number and name

DL Dry Lichen 02: Pl-Kinnikinnick-Cladonia 02: Pl-Juniper-Ricegrass

LM Lichen-Moss 01(b): Pl-Feathermoss-Cladina, 03: Pl-Feathermoss-CladinaSubmesic Phase

M Moss 01(a): Pl-Feathermoss-Cladina, 01: Sxw-Spirea-purple peavinemesic phase

AF Aspen Forest no equivalent (seral) no equivalent (seral)

SF Seepage Forest 05: Sxw-Horsetail; and 06: Sxw-Horsetail- 08: Sxw-Twinberry-Coltsfoot; 07:Glow moss Sxw-Horsetail; and 08: Act-Dogwood-

Prickly rose

SF(2) Seepage Phase 04: Sxw-Scrub birch-Feathermoss N/A

FW and NW Forested and 07: Sb-Scrub birch-sedge; 31: Non-forested 09: Sb-Creeping snowberry-SphagnumNon-forested Wetlands bog; and 32: Non-forested fen/marsh 10: Sb-Soft-leaved sedge-Sphagnum;

31: Non-forested bog; and 32: Non-forestedfen/marsh

a Site Series names and numbers correspond to the new correlated nomenclature in: Banner, A., W. MacKenzie, S. Haeussler,S. Thomson, J. Pojar and R. Trowbridge. [1993]. A field guide to site identification and interpretation for the Prince Rupert ForestRegion. B.C. Min. For., Res. Br., Victoria, B.C. Land Manage. Handb. No. 26. In preparation.

b Tree species abbreviations as follows: Pl = lodgepole pine, Sxw = hybrid white spruce, Sb = black spruce.


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APPENDIX 2. Raw data for Tables 6−8, 13−16

TABLE A2.1. Total area (hectares) of Caribou Habitat Types, forest cover types, and caribou habitat/forestcover combinations for all Caribou Management Zones combined in the Lakes (CMZ 2, 4, 8,9, 10, 11) and Prince George (CMZ 1, 2, 3, 4, 5, 6, 7, 8, 12) Timber Supply Areas

Lakes TSA Prince George TSA

% ha % ha

CARIBOU HABITAT TYPES

DLLM Mature 4.9 6 426 1.6 2 753Immature 5.0 6 569 2.6 4 409

LM Mature 15.7 20 838 6.8 11 621Immature 4.6 6 113 7.4 12 514

DLLM MOSAIC Mature 2.4 3 151 5.0 8 536Immature 3.3 4 330 1.9 3 201

MDLLM Mature 13.1 17 386 16.0 27 225Immature 5.5 7 212 3.2 5 325

MSF/AF Mature 23.7 31 416 17.7 30 100Immature 4.3 5 623 3.9 6 605

WETLANDS Forested 0.5 613 2.0 3 424

Non forested 2.3 3 002 3.2 5 440

LAKES 14.4 19 011 2.7 4 590

Not mapped 0.3 391 26.0 44 155

TOTAL 100.0 132 081 100.0 169 898

FOREST COVER TYPES

PINEMature Low 1.0 1 342 4.1 6 992

Poor 23.5 30 981 20.2 34 227Medium 10.2 13 490 6.7 11 385

Immature Low 1.2 1 590 1.5 2 615Poor 9.0 11 921 4.3 7 330Medium 14.3 18 922 18.1 30 737

PINE/SPRUCEMature Low 1.8 2 369 7.5 12 790

Poor 5.0 6 561 9.3 15 700Medium 5.6 7 342 4.7 8 038

Immature Low 0.4 487 0.3 518Poor 0.6 762 1.3 2 138Medium 4.5 5 947 2.7 4 543

WETLANDS 5.1 6 777 6.3 10 724

LAKES 14.5 19 212 2.9 4 924

OTHER 3.3 4 358 10.1 17 233

Not Mapped 0.0 21 0.0 3

TOTAL 100.0 132 081 100.0 169 898


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TABLE A2.1. (Continued)

Lakes TSA Prince George TSA

% ha % ha

CARIBOU HABITAT/FOREST COVER OVERLAY

DLLMMature Low 0.1 92 0.3 453

Poor 2.9 3 774 0.5 822Medium 1.4 1 840 0.7 1 243

Immature Low 0.0 44 0.5 806Poor 1.7 2 236 0.9 1 522Medium 2.7 3 583 1.0 1 641

LMMature Low 0.7 971 0.6 969

Poor 7.4 9 793 2.9 4 935Medium 6.8 8 958 3.0 5 117


DLLM MOSAICMature Low 0.1 127 0.6 982

Poor 1.1 1 421 1.4 2 334Medium 0.8 987 2.2 3 778

Immature Low 0.1 188 0.5 803Poor 1.7 2 255 0.4 732Medium 0.9 1 200 0.8 1 305

MDLLMMature Low 1.0 1 264 2.1 3 505

Poor 6.4 8 486 6.7 11 433Medium 5.3 6 979 6.3 10 629

Immature Low 0.5 688 0.3 486Poor 1.4 1 820 0.4 704Medium 3.2 4 285 2.1 3 563

MSF/AFMature Low 1.3 1 662 1.5 2 523

Poor 11.4 15 112 8.3 14 182Medium 9.1 12 054 5.9 10 000


WETLANDS 2.5 3 277 3.7 6 215

LAKES 14.4 19 081 2.8 4 727

OTHERWetland/Forest Overlap 3.7 4849 4.3 7337

Lake/Forest Overlap 0.1 153 0.1 153

Alpine 0.0 0 2.8 4 839

Other 3.3 4 353 2.8 4 804

Not mapped 0.3 413 23.1 39 319

TOTAL 100.0 132 082 100.0 169 898

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APPENDIX 3. Area inclusion factors for problem forest types, Prince George TimberSupply Area

TABLE A3.1. Area inclusion factors for mature problem types in the Prince George Timber Supply Area,Supply Block D - Ootsa Public Sustained Yield Unit (PSYU)

Type groupa Age classa Height classa Stocking classa Area inclusion factorb

18−20 7−9 3−4 1 0.506 3−4 0 0.50

7−9 3−4 2 0.107−9 2 1 0.10

6 2 0 0.107−9 2 2 0.00

21−26 7−9 3−4 1 0.956 3−4 0 0.95

7−9 3 2 0.207−9 4 2 0.307−9 2 2 0.00

21 7−9 2 1 0.206 2 0 0.20

22, 23, 26 7−9 2 1 0.106 2 0 0.10

24 7−9 2 1 0.206 2 0 0.20

25 7−9 2 1 0.056 2 0 0.05

28−30 5−9 4 2 0.505−9 3 2 0.665−9 3 3 0.568−9 3 4 0.205−9 2 2 0.055−9 2 3 0.405−9 2 4 0.00

31 5−9 3−4 1 0.204 3 0 0.20

5−9 4 2 0.055−9 3 2 0.075−9 3 3 0.027−8 3 4 0.005−9 2 1−4 0.00

4 2 0 0.00

a Type groups, age classes, height classes, and stocking classes are described in B.C. Ministry of Forests (1990).b Area inclusion factors include opportunity wood sale.


44

TABLE A3.2. Area inclusion factors for Environmentally Sensitive Areas, and immature problem types inthe Prince George Timber Supply Area, Supply Block D - Ootsa PSYU.

Environmentally Sensitive Areas (ESA)

ESA categorya Area inclusion factor

W 0.30I 0.10P 0.25R 0.30S 0.20

Immature Problem Types

Type groupa Age classa Site classa Area inclusion factor

18−19 1−5 G, M, P 0.34

20 1−5 G, M, P 0.46

21, 22, 24, 25 1−5 G,M 0.931−5 P 0.76

28−30 1−3 G,M 0.901−3 P 0.49

26 1−5 G, M, P 0.60

31 1−3 G, M, P 0.10

a ESA categories, inventory type groups, age classes, and site classes are described in B.C. Ministry of Forests (1990).


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APPENDIX 5. Average mean annual increment (MAI) estimates (m3/ha⋅yr-1) foranalysis units in the Prince George and Lakes Timber Supply Areas

PRINCE GEORGE TIMBER SUPPLY AREA

Analysis unit Type groupb Site classb Average MAIa

(m3/ha⋅yr-1)

5 18−19 G, M, P 1.176 20 G, M, P 1.967 21, 22, 24, 25 G, M 2.568 21, 22, 24, 25 P 1.739 28−30 G, M 2.30

10 28−30 P 1.2211 26, 31 G, M, P 2.04

LAKES TIMBER SUPPLY AREA

Average MAIa

(m3/ha⋅yr-1)

Analysis unit Type group Site class Stocking classb

Old utilization New utilizationlevelsc levelsd

1 18−20 G, M, P All 2.33 2.332 21−26 G, M All 2.25 2.303 21−26 P All 1.51 1.554 28−30 G All 2.82 2.895 28 M 1 1.96 1.976 28 M 2, 3 2.10 2.817 28 P 1 1.42 1.438 28 P 2, 3 1.42 1.529 29−30 M All 2.26 2.30

10 29−30 P All 1.54 1.58

a Average MAI was calcualted by D. Robb, B.C. Ministry of Forests, Prince George Region) for the Prince George TSA, and by G.Hoehne (B.C. Ministry of Forests, Burns Lake District, Prince Rupert Region) for the Lakes TSA, using the B.C. Ministry of ForestsYIELD program (B.C. Ministry of Forests 1988). Average MAI was calculated based on the average New Site Index of analysis unitsafter net downs.

b Inventory type groups, site classes, and stocking classes are described in the B.C. Ministry of Forests (1990).c Lakes TSA old utilization levels: Pine - 15.0 cm; Spruce - 17.5 cm; Balsam - 17.5 cm.d Lakes TSA new utilization levels: Pine - 12.5 cm; Spruce - 15.0 cm; Balsam - 17.5 cm.

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LITERATURE CITED

Agriculture Canada Expert Committee on Soil Survey. 1987. The Canadian system of soil classification.Agric. Can., Res. Br., Ottawa, Ont. Publ. 1646. 164 p.

Ahti, T. 1977. Lichens of the Boreal Coniferous Zone. In Lichen ecology. M.R.D. Seaward (editor).Academic Press, London, pp. 145−181.

Banner, A., J. Pojar, R. Trowbridge, and A. Hamilton. 1986. Grizzly bear habitat in the Kimsquit River Valley,coastal British Columbia: classification, description, and mapping. In Proc. Grizzly Bear HabitatSymp., 30 April−2 May, 1985, Missoula, Mont. G.P. Contrereas and K.E. Evans (compilers). U.S. Dep.Agric. For. Serv., Intermount. Res. Sta., Ogden, Utah. Gen. Tech. Rep. INT-207, pp. 36−49.

Banner, A., W. Mackenzie, S. Haeussler, S. Thomson, J. Pojar and R. Trowbridge. [1993]. A field guide tosite identification and interpretation for the Prince Rupert Forest Region. B.C. Min. For., Res. Branch,Victoria, B.C., Land Manage. Handb. No. 26. In preparation.

Bergerud, A.T. 1974. Decline of caribou in North America following settlement. J. Wildl. Manage.38:757−770.

Bergerud, A.T., R.D. Jakimchuk, and D.R. Carruthers. 1984. The Buffalo of the North: caribou (Rangifertarandus) and human developments. Arctic 37:7−22.

Bergerud, A.T. and R.E. Page. 1987. Displacement and dispersion of parturient caribou at calving asantipredator tactics. Can. J. Zool. 62:1566−1575.

British Columbia Ministry of Forests. 1985. Lakes TSA Timber Supply analysis report. Planning andInventory Br., Victoria, B.C.

. 1988. Yield prediction system, version 3, October 1988. Users’ guide. Planning and InventoryBr., Victoria, B.C.

. 1990. Standards and procedures for the acquisition of forest inventory data. Inventory Br.,Victoria, B.C.

Cichowski, D.B. 1989. Seasonal movements, habitat use, and winter feeding ecology of woodland caribouin west-central British Columbia. MSc. thesis. Univ. B.C., Vancouver, B.C. 143 p.

Clement, C.J.E., A. Banner, and J. Pojar. 1987. Winter habitat units of caribou in the Entiako River area,west central British Columbia. (4) 1:50 000 mapsheets. B.C. Min. For., Smithers, B.C.

Darby, W.R., H.R. Timmermann, J.B. Snider, K.F. Abraham, R.A. Stefanski, and C.A. Johnson. 1989.Woodland caribou in Ontario: background to a policy. Ont. Min. Natural Resources. 38 p.

Edmonds, E.J. 1988. Population status, distribution and movements of woodland caribou in west centralAlberta. Can. J. Zool. 66:817−826.

Edmonds, E.J. and M. Bloomfield. 1984. A study of woodland caribou (Rangifer tarandus caribou) in westcentral Alberta, 1979−1983. Alta. Energy and Natural Resources, Fish and Wildl. Div., Edmonton,Alta. 203 p.

Farnell, R. and J. McDonald. 1987. The demography of Yukon’s Finlayson Caribou Herd, 1982−1987.Yukon Renewable Resources, Whitehorse, Yukon Terr. 54 p.

Gasaway, W.C., R.O. Stephenson, J.L. Davis, P.E.K. Shepherd, and O.E. Burris. 1983. Interrelationships ofwolves, prey and man in interior Alaska. Wildl. Monogr. No. 84. 50 p.

Hale, M.E. Jr. 1983. The biology of lichens. Edward Arnold Ltd., London. 190 p.

Hale, M.E. and W.L. Culberson. 1970. A second checklist of the lichens of the continental United States andCanada. Bryologist 63:137−172.

SEQ 5162 JOB LMR83-007-007 PAGE-0048 LIT CIT REVISED 14JUN00 AT 09:00 BY BC DEPTH: 60 PICAS WIDTH 42.09 PICAS COLOR LEVEL 1

48

Holland, S. 1976. Landforms of British Columbia: a physiographic outline. B. C. Dep. Mines and PetroleumResources, Victoria, B.C. Bull. 48. 138 p.

Ireland, R.R., C.D. Bird, G.R. Brassard, W.B. Schofield, and D. H. Vitt. 1980. Checklist of the mosses ofCanada. National Museums of Canada, Ottawa, Ont. Publ. in Botany No. 8. 75 p.

Johnson, E.A. 1981. Vegetation organization and dynamics of lichen woodland communities in the North-west Territories, Canada. Ecology 63:200−215.

Kershaw, K.A. 1977. Studies on lichen-dominated systems. XX. An examination of some aspects of thenorthern boreal lichen woodlands in Canada. Can. J. Bot. 55:393−410.

Klinka, K., R.N. Green, R.L. Trowbridge, and L.E. Lowe. 1981. Taxonomic classification of humus forms inecosystems of British Columbia. First approx. B.C. Min. For., Victoria, B.C. Land Manage. Rep. No. 8. 54 p.

Lewis, T., J. Pojar, D. Holmes, R. Trowbridge, and K.D. Coates. 1986. A field guide for identification andinterpretation of the Sub-Boreal Spruce Zone in the Prince Rupert Forest Region. B.C. Min. For.,Victoria, B.C. Land Manage. Handb. No. 10. 102 p.

Marshall, R. 1985. Second progress report of the Tweedsmuir-Entiako caribou study, June 1984−April1985. BC Environ., Smithers, B.C. 46 p.

Mitchell, W.R., R.N. Green, G.D. Hope, and K. Klinka. 1989. Methods for biogeoclimatic ecosystemmapping. B.C. Min. For., Victoria, B.C. Res. Rep. 89002-KL. 33 p.

Morash, P.R. and G.D. Racey. 1989. The northwestern Ontario Forest Ecosystem Classification as adescriptor of woodland caribou (Rangifer tarandus caribou) range. Ontario Min. Natural Resources,NWOFTDU Tech. Rep. Draft.

Ontario Ministry of Natural Resources. 1990. Timber management guidelines for the provision of woodlandcaribou habitat. Wildl. Br. Draft.

PAMAP Graphics Ltd. 1989. PAMAP Geographic Information Systems user’s guide: Version 2.2. PAMAPGraphics Ltd. Victoria, B.C.

Pojar, J., D. Demarchi, M. Fenger, T. Lea, and B. Fuhr. 1988. Biogeoclimatic and ecoregion units of thePrince Rupert Forest Region. (2) 1:500 000 mapsheets. B.C. Min. For., Victoria, B.C.

Rowe, J.S. 1984. Lichen woodland in northern Canada. In Northern ecology and resource management.Univ. Alta. Press, Edmonton, Alta., pp. 225−237.

Seip, D.R. 1992. Factors limiting woodland caribou populations and their interrelationships with wolves andmoose in southeastern British Columbia. Can. J. Zool. 70:1494−1503.

Stevenson, S.K. and D.F. Hatler. 1985. Woodland caribou and their habitat in southern and central BritishColumbia. B.C. Min. For., Victoria, B.C. Land Manage. Rep. No. 23, Vol. 1. 354 p.

Taylor, R.L. and B. MacBryde. 1977. Vascular plants of British Columbia: a descriptive resource inventory.The Botanical Garden, Univ. B.C., Vancouver, B.C. Tech. Bull. No. 4. 754 p.

. 1978. New taxa and nomenclatural changes with respect to vascular plants of BritishColumbia: a descriptive resource inventory. Can. J. Bot. 56:184−195.

management strategy and options for the tweedsmuir-entiako

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