Buda et al. 2011 CNFER IP-005 005 Centre for Northern ... · i. Buda et al. 2011 CNFER IP-005. FOREWORD. This technical report is intended to provide information to planning teams

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Buda et al. 2011 CNFER IP-005

Silvicultural Practices forEastern White Cedar in BorealOntario

Centre for Northern Forest Ecosystem Research Technical Report 005

NorthwestScience & Information

NortheastScience &Information

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Buda et al. 2011CNFER IP-005

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Centre for Northern Forest Ecosystem Research Technical Report 005

Silvicultural Practices forEastern White Cedar in BorealOntario

N. J. Buda1, R. G. White2, G. J. Kayahara3, S. F. Duckett4, and B. E. Fox4

1Centre for Northern Forest Ecosystem Research2Northeast Science and Information

3Northwest Science and Information4Forest Health and Silviculture Section

September 2011

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(Centre for Northern Forest Ecosystem Research Technical Report 005)Silvicultural Practices for Eastern White Cedar in Boreal Ontario

Available in print: ISBN 978-1-4435-7270-5Available also on the Internet (PDF): ISBN 978-1-4435-7271-2

Cette publication spécialisée n’est disponible qu’en anglais.

© 2011, Queen’s Printer for OntarioPrinted in Ontario, Canada

Single copies of this publication are available from:

Centre for Northern Forest Ecosystem ResearchMinistry of Natural Resources955 Oliver RoadThunder Bay, ONCanada P7B 5E1Phone: (807) 343-4000Fax: (807) 343-4001

Please cite as:

Buda, N. J., G. J. Kayahara, R. G. White, S. F. Duckett and B. E. Fox. 2011. Silvicultural Practices for Eastern White Cedar in Boreal Ontario. Technical Report CNFER TR-005. Ontario Ministry of Natural Resources, Centre for Northern Forest Ecosystem Research, Thunder Bay, Ontario, Canada. 51pp.

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FOREWORD

This technical report is intended to provide information to planning teams to improve understanding of eastern white cedar silvics and assist in the development of silvicultural prescriptions for managing this species in boreal Ontario. This document is not a silviculture guide and the views, conclusions, and recommendations are those of the authors and should not be construed as policy by the Ontario Ministry of Natural Resources. Mention of trade names does not imply endorsement. Where available, aboriginal traditional knowledge of the management and special values associated with cedar will be an important consideration in the formation of overall approaches to managing cedar.

EXECUTIVE SUMMARY

This report was written in response to growing interest in eastern white cedar (Thuja occidentallis L.) management in boreal Ontario. This document focuses on the silvicultural aspects of managing cedar both in pure and mixed stands. The application of selected silvicultural practices described in this report was developed from the best available information which included a variety of sources such as: published research in Quebec, Southern Ontario and the Lake States; current Ontario silviculture guides; several cedar workshops and tours; and field investigations across boreal Ontario.

The first four sections contain descriptive background information used to develop the cedar silviculture prescriptions, and provide interested users with the rationale behind the prescriptions. Critical silvics of cedar are briefly described including climatic range, common site conditions, reaction to competition, and susceptibility to frost, flood, drought, fire, diseases and insects. Genetic considerations, reproduction methods, seedbeds, stand structure and dynamics, site quality and growth rates are also discussed. Although silviculture systems are described in detail in Ontario’s silviculture guides, the Reserve Shelterwood method is introduced, which is a new concept to Ontario. The Reserve Shelterwood system is particularly important in Ecoregions 3E and 4E of northeastern Ontario, where wetter climates are associated with longer fire cycles, allowing stands of uneven-aged, mid- and late-seral succession stage forests to evolve. Finally a description of Ontario’s ecosites associated with cedar is given for the development of Silviculture Ground Rules.

This background information was used to develop the silvicultural systems and harvest methods for upland and lowland sites. The standard silviculture systems and harvest methods outlined in current silviculture guides are shown as options for managing cedar and include clearcut with seed trees, strip and patch cuts and advance growth, uniform and strip shelterwood, and group selection.

Cedar silviculture practices are shown with general stand/site suitability criteria, restrictions, objectives, prerequisites, harvest methods, renewal approaches, and discouraged practices. Operational considerations for promoting cedar are also outlined including pre-harvest treatments, harvesting and regeneration methods (natural and artificial), site preparation and competition management/tending on lowland and upland sites. Practices to maintain genetic diversity are briefly discussed. Site index and volume tables, a suggested pre-harvest assessment/prescription method and a cedar regeneration monitoring procedure are also provided.

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RÉSUMÉ

Le présent rapport a été rédigé compte tenu de l’intérêt grandissant pour la gestion du thuya occidental (Thuja occidentallis L.) dans le nord de l’Ontario. Ce document porte sur les aspects sylvicoles de la gestion du thuya, dans les peuplements purs comme dans les peuplements mixtes. L’application des pratiques sylvicoles choisies et décrites dans le présent rapport a été mise au point à partir des meilleures informations disponibles, issues d’une variété de sources, notamment : des recherches publiées au Québec, dans le sud de l’Ontario et les États des Grands Lacs; les derniers guides ontariens de sylviculture; plusieurs ateliers et visites axés sur le thuya; ainsi que des enquêtes sur le terrain dans l’ensemble du nord de l’Ontario.

Les quatre premières sections contiennent les renseignements généraux descriptifs utilisés dans la mise au point des prescriptions sylvicoles relatives au thuya et expliquent aux utilisateurs intéressés les raisons ayant mené à l’élaboration de ces prescriptions. Les écologies forestières cruciales pour le thuya sont brièvement décrites et comprennent les changements climatiques, l’état commun des sites, la réaction à la concurrence et la sensibilité à gel, aux inondations, à la sécheresse, au feu, aux maladies et aux insectes. Des considérations d’ordre génétique, les méthodes de reproduction, les planches de semis, la structure et la dynamique des peuplements, la qualité des sites et les taux de croissance sont aussi analysés. Bien que les systèmes sylvicoles soient décrits en détail dans les guides de sylviculture de l’Ontario, le mode de régénération de réserve par coupes progressives uniformes (« Reserve Shelterwood »), nouveau concept pour l’Ontario, est introduit. Ce mode de régénération est particulièrement important pour les écorégions 3E et 4E du Nord-Est de l’Ontario, où des climats plus humides sont associés à des cycles de feu plus longs, ce qui permet aux peuplements d’âge inégal et aux forêts à stades de succession moyens et tardifs d’évoluer. Enfin, une description des écosites ontariens associés au thuya est fournie en vue de l’élaboration de principes fondamentaux en matière de sylviculture.

Ces renseignements généraux ont été utilisés pour élaborer les systèmes sylvicoles et les méthodes de récolte pour les sites des hautes et basses terres. Les systèmes sylvicoles et les méthodes de récolte standards décrits dans les guides de sylviculture actuels sont inclus à titre de choix dans la gestion du thuya et comprennent la coupe à blanc avec semenciers, la coupe par bandes et par trouées et semis préexistants, le mode de régénération par coupes progressives uniformes et par bandes ainsi que le jardinage par bouquets.

Les pratiques sylvicoles appliquées au thuya expliquées dans ce document comprennent les critères de pertinence, les restrictions, les objectifs, les conditions préalables, les méthodes de récolte, les modes de régénération et les pratiques non recommandées pour les peuplements et les sites généraux. Des considérations opérationnelles visant la promotion du thuya sont aussi passées en revue, notamment les traitements précédant la récolte, les méthodes de récolte et de régénération (naturelles et artificielles), la préparation des sites de même que la gestion et les soins sylvicoles de la concurrence sur les sites de basses et de hautes terres. Les pratiques visant la conservation de la diversité génétique sont brièvement analysées. Un index des sites et des tables dendrométriques, une méthode suggérée d’évaluation et de prescription prérécolte et une procédure de surveillance de la régénération du thuya sont aussi fournis.

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ACKNOWLEDGEMENTS

The authors thank Dr. Darwin Burgess, Canadian Forest Service; Dr. Ray Miller, Michigan Agricultural Experiment Station & Michigan State University; Dr. Rongzhou Man, Ontario Forest Research Institute, OMNR; Fred Pinto, Southern Science and Information Section, OMNR; Mike Brienesse, Forest Policy Section, OMNR; Dr. Dennis Joyce, Forest Health and Silviculture Section, OMNR; and, Dr. Bill Parker, Lakehead University for their valuable input and review comments on the information presented. Thanks to Neil Stocker for his role in helping to facilitate and coordinate work on this report in the early stages. We are also grateful to Marlene Rhyner, Dryden District, OMNR for permission to use her photos. Thanks to Diana Callaghan for completing an editorial review of the document, however, any errors or omissions are the responsibility of the authors. Special thanks are due to Brooke Pilley, Centre for Northern Forest Ecosystem, OMNR for his work on desktop publishing this document.

Though this document appears as a Centre for Northern Forest Ecosystem report, it is the result of a Forest Health and Silviculture Section initiative.

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TABLE OF CONTENTS

FOREWORD ............................................................................................................................................... i

SUMMARY .................................................................................................................................................. i

RÉSUMÉ ..................................................................................................................................................... ii

ACKNOWLEDGEMENTS .......................................................................................................................... iii

TABLE OF CONTENTS ............................................................................................................................. iv

LIST OF TABLES ....................................................................................................................................... v

LIST OF FIGURES ..................................................................................................................................... v

1.0 INTRODUCTION ................................................................................................................................. 11.1 Scope of Application ............................................................................................................. 2

2.0 CRITICAL SILVICS .............................................................................................................................. 32.1 Climatic Range and Site Conditions ...................................................................................... 32.2 Reaction to Competition ........................................................................................................ 32.3 Frost Resistance .................................................................................................................... 42.4 Flood and Drought Tolerance ............................................................................................... 42.5 Fire Tolerance ........................................................................................................................ 42.6 Genetics ................................................................................................................................. 42.7 Vegetative Reproduction ....................................................................................................... 52.8 Sexual Reproduction ........................................................................................................... 52.9 Seedbeds .............................................................................................................................. 62.10 Natural Disturbances ............................................................................................................ 82.11 Diseases ............................................................................................................................... 92.12 Insects ................................................................................................................................. 10

3.0 SITE QUALITY AND GROWTH AND YIELD .................................................................................... 103.1 Volume Tables ....................................................................................................................... 123.2 Cull Estimation ....................................................................................................................... 12

4.0 SILVICULTURAL PRACTICES ......................................................................................................... 124.1 Silvicultural Systems and Harvest Methods ........................................................................ 12

Reserve Shelterwood System ....................................................................................... 134.2 Ecosites for Cedar Management ......................................................................................... 144.3 Genetics and Management .................................................................................................. 14

5.0 SELECTING A SILVICULTURE SYSTEM AND HARVEST METHOD ............................................ 155.1 Pre-harvest Assessment ........................................................................................................ 175.2 Silviculture Practices For Eastern White Cedar in Boreal Ontario: Introduction to Table 1 ... 175.3 Operational Considerations for Promoting Cedar: Table 2 ..................................................... 185.4 Monitoring ............................................................................................................................... 18

6.0 LITERATURE CITED ........................................................................................................................ 33

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APPENDIX A ........................................................................................................................................... 38APPENDIX B ........................................................................................................................................... 39APPENDIX C ........................................................................................................................................... 40APPENDIX D ........................................................................................................................................... 42

LIST OF TABLES

Table 1. Silvicultural practices for eastern white cedar in boreal Ontario. ..................................... 22

Table 2. Operational considerations for promoting cedar. ....................................................... 28

LIST OF FIGURES

Figure 1. Map showing the area of boreal Ontario to which this technical note is applicable. Boreal Ontario is considered to include ecoregions 3E, 3W, 3S, 4E, and boreal conditions in 4S, 4W, and 5S. Source: Crins et al. 2009. ............................................................ 2

Figure 2. Mature cedar cones ready to open. Photo by B. Fox. ............................................ 6

Figure 3. Cedar natural regeneration on moss-covered, decaying cedar logs. Photos by B. Fox and M. Rhyner. ............................................................................................................... 7

Figure 4. Decaying stumps provide good cedar seedbeds by improving moisture, nutrient, and light availability and reducing the opportunity for germinants to be covered by litter. Photos by N. Buda and M. Rhyner. ............................................................................................... 7

Figure 5. Narrow harvest corridors with light slash and good cedar seedbed available. Photo by B. Fox. .............................................................................................................................. 8

Figure 6. Cedar is shallow rooted; roots are vulnerable to decay. Photos by N. Buda and B. Fox. .. 9

Figure 7. Heartwood rot in cedar. Photo by B. Fox. .................................................................... 10

Figure 8. Large, high-quality cedar with good form and growth. Photos by B. Fox. ................... 11

Figure 9. Typical structure of old growth cedar stands with multiple size and age classes. Photo by B. Fox. ............................................................................................................................. 14

Figure 10. Leaning cedar trees are an important part of stand structure. Photo by B. Fox. ....... 15

Figure 11. Flowchart illustrating the differences between various silviculture systems in terms of current stand composition, stand structure objectives (even-aged or uneven-aged), regeneration (natural or artificial), and shelter requirements. ................................................ 16

Figure 12. Narrow skid trail with light ground disturbance and same area seven years later with abundant hardwood competition. Photo by B. Fox. ........................................................ 19

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Figure 13. Cedar seeded in on hair cap moss (Polytrichum commune) on a disturbed skid trail with optimum partial shading. Photos by B. Fox and M. Rhyner. ............................................. 19

Figure 14. Upland mixedwood site with cedar clump and abundant hardwood competition. Photo by B. Fox. ............................................................................................................................. 20

Figure 15. Cedar 1-0 Mutlipot 45’s planting stock. Photos by B. Fox. ........................................ 20

Figure 16. Upland cedar natural regeneration growing well seven years after harvesting. Photo by B. Fox. ............................................................................................................................ 20

Figure 17. Examples of narrow corridors with optimum 50% shading for cedar natural regeneration. Photos by B. Fox. ............................................................................................................ 21

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1.0 INTRODUCTION

This technical report was written in response to growing interest in eastern white cedar (Thuja occidentalis L.) management in boreal Ontario. This document focuses specifically on the silvicultural aspects of managing cedar in both pure stands and in mixture with other species. There are many values from, and uses for, cedar which are described in other publications.

It is recognized that there has been little silvi-culture research in general for eastern white cedar (Hofmeyer et al. 2009a) or management experience in boreal Ontario, largely because of cedar’s ‘undefined economic value’ (Miller et al. 1990). Efforts to manage and market the resource in boreal Ontario have been sporadic and the resources needed to develop and implement appropriate management systems for cedar have been lacking.

The silvicultural practices in this report were developed from the best available information which included a wide variety of sources, such as:

Published research from Quebec, 1. southern Ontario, and the Lake States

Current silviculture guides including 2. A Silvicultural Guide for the Great Lakes-St Lawrence Conifer Forest in Ontario (OMNR1998), A Silviculture Guide to Managing Southern Ontario Forests (OMNR 2000), and The Ontario Tree Marking Guide (OMNR 2004)

Cedar workshops and tours from 1999 3. to 2009 in Hearst, Michigan, Dryden, Chapleau, and Timmins

Field investigations and observations 4. from numerous sites across boreal On-tario

The silviculture guides mentioned above were intended to be applied mainly in the Great Lakes-St. Lawrence Region, and have limited information on cedar management for boreal Ontario. This technical report was designed to address conditions that are different in boreal Ontario, such as:

Topography, landforms, climate, growth 1. rates, and site/soil conditions.

Occurrence of a significant amount of 2. cedar on upland ecosites and in mixed-wood forest units (cedar individuals or clumps often occur as a minor com-ponent of mixedwood stands).

Structure of cedar stands and manage-3. ment objectives/direction (e.g., manag-ing for caribou habitat). Cedar stands are often made up of trees in a range of size and age classes. Fire cycles in ecoregions 3E and 4E for example are long, and have resulted in old stands with multi-age class structures. Hence, where the goal is to emulate natural disturbances in a landscape such as this, a higher proportion of uneven-aged systems may be appropriate.

Limited all-weather road access (es-4. pecially in the claybelt of northeastern Ontario), which may make it impractical to utilize silvicultural systems requir-ing periodic return cuts such as strip, patch, or shelterwood.

Economics, scale of operations, history 5. of management, ecology, and associ-ated species.

Silvicultural treatment packages for managing species which occur outside the zones tar-geted by existing guides, or for those species not included in guides, should be developed based on the best available science, advice such as that provided in this technical report, and previous experience.

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1.1 Scope of ApplicationThe advice contained in this technical report is intended to provide guidance to practitioners on cedar management in boreal Ontario which is considered to include ecoregions 3E, 3W, 3S, 4E, and boreal conditions in 4S, 4W, and 5S as shown in Figure 1.

This technical report identifies and suggests some new approaches to managing cedar not previously considered for use in Ontario, including reserve shelterwood, shelterwood (strip and patch) and clearcut with seed tree,

described in detail in Table 1 (page 42). Addi-tionally, this report outlines suggested ap-proaches to managing cedar when it occurs in mixedwood stands.

This technical report has been organized into five broad sections. The first four sections provide descriptive background information used to develop the cedar silviculture prescrip-tions presented in Section 5.0. Section 2.0 Critical Silvics describes key autecological and synecological characteristics of cedar that are necessary in order to understand the rationale

2W

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Ecozones, Ecoregions,and Ecodistricts ofOntario

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This map is illustrative only. Do not rely on it asbeing a precise indicator fo routes, locations offeatures, nor as a guide to navigation.

(c) 2009, Queen's Printer for Ontario.

Figure 1. Map showing the area of boreal Ontario to which this technical note is applicable. Boreal Ontario is considered to include ecoregions 3E, 3W, 3S, 4E, and boreal conditions in 4S, 4W, and 5S. Source: Crins et al. 2009.

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behind the silviculture and harvest methods presented here. Section 3.0 Site Quality and Growth and Yield is necessary information for volume estimation and growth prediction. Al-though silviculture systems are described in detail in Ontario’s silviculture guides (OMNR 1997, 1998, 2000, 2003), Section 4.0 Silvi-cultural Practices introduces the Reserve Shelterwood method, which is a new concept to Ontario, and describes Ontario’s ecosites associated with cedar which is required know-ledge for the development of Silviculture Ground Rules (OMNR 2009). In addition, since various partial harvest systems form a large proportion of the cedar harvest systems presented in this document, and given On-tario’s past experience with high-grading in tolerant hardwood forests, special emphasis is placed upon considerations for genetics and management.

Sections 2.0 to 4.0 provide the background information used to develop Section 5.0 Se-lecting a Silviculture System and Harvest Method, and provides interested users with the rationale behind the prescriptions. Section 5.0 is meant to be stand-alone for planning and operational forestry staff only requiring the operational details of the practices. The back-ground information from Sections 2.0 to 4.0 can then be referenced only as needed by the practitioner.

2.0 CRITICAL SILVICS

2.1 Climatic Range and Site Conditions

Eastern white cedar occurs across a range of sites with moderate to cold temperature regimes throughout the boreal forest region (Rowe 1972). The northern limit of cedar ex-tends to the northern edge of the boreal for-est, and the southern limit, in the Lake States, corresponds to a mean annual temperature isotherm of 10°C (Sims et al. 1990).

Although it grows best on upland sites, east-ern white cedar is able to compete on sites

at the extremes of drainage and pH. As a re-sult, it predominately occupies cool, moist to wet soils and sites that are more humid and cooler than the regional average throughout its range. On organic soils, cedar growth is best on soils with shallow organic layers overlying loamy or sandy sub-soils and sites with flowing groundwater, well decomposed organic layers, and neutral or slightly basic pH (Miller 1990). On a 5-unit scale for moisture, nutrient, and heat requirements (where 1=least required to 5=most required), cedar ranked 4.2, 2.3, and 1.3, respectively (Sims et al. 1990).

Cedar is a slow growing and long-lived tree. Cedar trees growing on cliff faces of the Ni-agara Escarpment in southern Ontario have been found to be the oldest living trees in On-tario and in Canada, east of British Columbia (Kelly et al. 1994). Cedar trees up to 1890 years old have been found on the Niagara Escarpment (www.ancientforest.org/oldtrees.htm). In boreal Ontario, a 344-year-old tree was recorded in Sleeping Giant Provincial Park near Thunder Bay and a 326-year-old cedar was found on the Lake Abitibi Model Forest near Cochrane (www.ancientforest.org/oldtrees.htm). A 900-year-old living cedar was also documented in northwestern Quebec (Ar-chambault and Bergeron 1992).

2.2 Reaction to Competition

Eastern white cedar is classed as shade toler-ant but it has been placed in three categor-ies, ranging from very tolerant, tolerant, to intermediate. The variation probably exists because vegetative reproduction is considered more shade tolerant than reproduction from seedlings (Johnston 1990). On a detailed study of ecological requirements for a number of tree species in Minnesota, cedar was given a ranking of 1.2 on a 5-unit scale for light requirements (1=least required to 5=most re-quired) (Sims et al. 1990).

The best seedling height growth has been found to occur at 45% of full sunlight, but shoots and roots were heaviest when grown

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in full sunlight (Johnston 1990). Under dense overstories, larger populations of seedlings have been associated with greater light inten-sities in canopy gaps (Cornett et al. 2001).

Suppressed cedar trees are able to respond in increased growth with increasing light condi-tions even after extended periods of suppres-sion (Hofmeyer et al. 2010). Response to thin-ning cedar depends on site quality. In a well-drained swamp, a 45-year-old stand thinned to a residual basal area of 15.8 m2/ha more than doubled its basal area in eight years; a similar thinning on a poorly drained swamp showed no beneficial effect (Johnston 1990).

Cedar commonly occurs in even-aged and uneven-aged stands (Johnston 1990) but, due to stem rot in many stands, there are often difficulties in determining tree ages and stand structure.

2.3 Frost Resistance

Late spring frosts and frost heaving on sites subject to flooding, or with a high water table in the spring, may frequently cause consider-able mortality to seedlings (Godman 1958). Once established, eastern white cedar com-monly grows on low-lying areas prone to late-spring and early-fall frosts without displaying significant symptoms of frost damage (Sims et al. 1990).

2.4 Flood and Drought Tolerance

Moisture conditions play an important role in the establishment and development of east-ern white cedar. Adequate moisture supply is critical to germination and early survival. Seedlings initially develop taproots during the early years of growth, but they are replaced over time by a fibrous root system. Drought often causes a high percentage of the mortal-ity among cedar seedlings (e.g., one-third of the observed seedling mortality in one study) (Sims et al. 1990).

Although cedar occurs on a wide range of soil drainage conditions, including well- and rapid-ly-drained soils, cedar-dominated stands are found most often on low-lying, poorly drained sites (Sims et al. 1990). Cedar is very tolerant of frequent, well-aerated flooding (i.e., running water) for short periods of time (Ahlgren and Hansen 1957). Growth decreases, however, if aeration is restricted. Mortality may occur if root aeration decreases for lengthy periods during the growing season (i.e., two months or more) due to a rise in the water table or flood-ing (Sims et al. 1990).

2.5 Fire Tolerance

Cedar is very susceptible to damage from fire due to its very thin, flammable, shaggy bark and shallow rooting habit (Godman 1958), though cedar-dominated stands are often found on very poorly drained soils where fire is a lower-risk threat. If fire does occur, pure stands of cedar may become established (Barnes and Wagner 1981) since burnt organ-ic surfaces provide good seedbeds (Johnston 1977).

2.6 Genetics

Eastern white cedar is morphologically similar throughout its range, but range-wide proven-ance studies indicate that genetic variation does occur between provenances (for ex-ample, in bud set, flowering, and pollen disper-sal) (Burns et al. 1990). The existence of more than 120 ornamental cultivars, differing in foliage color and growth habit, also suggests that there may be significant genetic varia-tion among natural populations. There have been contradictory claims about the degree of genetic variability among cedar popula-tions though, including evidence from studies conducted in northwestern Ontario (e.g., Perry and Knowles 1990; Perry et al. 1990).

Some phenotypic traits are more strongly inherited than others. For example, wood properties tend to be more strongly inherited

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than growth traits and stem form.1 Many stem features, such as crooked, forked or cracked stems, lean, or sweep, are believed to be due to various environmental factors (e.g., brows-ing, snow and ice damage). Little information exists about the heritability of some other fea-tures, such as spiral grain.

Clearcut and partial cutting systems, if im-properly applied, can lower the genetic quality of subsequent generations (Joyce et al. 2001). If stands are clearcut and natural regenera-tion fails, local populations could be extirpated or completely removed, which may increase the isolation of remaining cedar patches and enhance the risk of genetic drift.2 As well, if residual stands are small and populations are reproductively isolated, inbreeding depression may result.3 Partial cuts can also reduce the size of isolated populations and increase the chances of in-breeding and genetic drift. In practice, these genetic concerns are greater over the long-term and reserved for highly fragmented populations.4

The need for active genetic management de-pends on the population size and the risk of in-creased fragmentation (Joyce et al. 2001). As a precaution, areas planted with cedar should be monitored to ensure regeneration is healthy and developing well.

The evolution of distinct upland and lowland

1 D. Joyce , OMNR Provincial Forest Geneticist, personal com-munication, 2009.

2 Genetic drift: random changes in the gene pool of small popu-lations leading to a loss of genetic variation (W. Parker, OFRI, Research Scientist, personal communication, 2010).

3 Inbreeding depression: the reduced fitness in a given popula-tion as a result of breeding related individuals. In general, the higher the genetic variation within a breeding population, the less likely it is to suffer from inbreeding depression. Breeding between closely related individuals, called inbreeding, may result in the manifestation of more recessive deleterious traits. The more genetically similar the parents are, the more often recessive traits appear in their offspring (http://en.wikipedia.org/wiki/Inbreeding_depression).

4 Fragmented population: species that occur as a major compo-nent of stands but have a patchy distribution in the landscape, that is, restrictive habitat and high density local populations, can be thought of as having a fragmented population structure (Joyce et al. 2001).

cedar ecotypes (i.e., subpopulations unique to different environments) has been sug-gested by studies of root morphology and seed development for lowland and upland seed sources (Habeck 1958; Musselman et al.1975). This hypothesis has been chal-lenged, however, by investigators of drought tolerance and productivity who found no inher-ent differences between cedar from upland and lowland sites (Hofmeyer 2008).

Due to the limited and sometimes contra-dictory information concerning the cedar gen-etic resource, precautionary approaches to its management are outlined in Section 4.3.

2.7 Vegetative Reproduction

Cedar can root from any part of a branch or stem if moisture conditions are favour-able (Johnston 1990). Layering is a common method of reproduction on organic soils where up to 60% of cedar regeneration has been re-ported to have originated from layering (Sims et al. 1990). Layering may result from sphag-num moss covering low-hanging branches or from the formation of new, upright stems that result if a tree tips over or falls flat in a swamp; the branches take root, grow upright and form a row of living trees along the buried trunk (Godman 1958). Seedlings as young as five-years-old can successfully regenerate by layering (Sims et al. 1990). Occasionally, twigs that have been clipped or broken off have been found rooted in sphagnum moss in natural stands (Godman 1958). Sprouts from roots or stumps are rare (Johnston 1990).

2.8 Sexual Reproduction

Flowering occurs in late April or early May, with cone formation in late June and matura-tion in mid-August. Male and female flowers develop on separate twigs or branchlets on the same tree. Male flowers are tiny, short-lived, and deciduous, and develop on branchlets near the base of the shoot. Female flowers are pinkish and appear at the tips of the short ter-minal branchlets (Johnston 1990).

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Cones are upright, small (about 1 cm long), egg-shaped, and mature after one season but remain attached to the tree until the follow-ing spring (Figure 2). Cedar is characterized by dependable annual seed production, with good to better seed crops produced every two to five years, and failures or medium crops in intervening years (Johnston 1990).

Seed production occurs in trees as young as 30-years-old, but peaks after age 75 (seeds are occasionally produced on trees as young as six-years-old). Good-to-better crops of cedar seed can be predicted by similar-sized crops in red maple the preceding spring (God-man and Mattson 1976).

Cones mature (Figure 2) and release seeds in the same year as they flower. Dispersal be-gins in mid-September, seven to ten days after cone ripening, and ends in November. Wind is the primary agent for dispersal. Cedar has a limited effective seeding distance which may be as short as 30 m under some conditions (Cornett et al. 2001).

Seeds display slight internal dormancy, which breaks while seeds are on the ground during the first winter. Fall sowing appears to be the best option (Johnston 1990), but germination normally begins in late May or early June and can be delayed until late July or early August. Cedar seeds are apparently no longer viable on the forest floor after one year (Johnston 1990).

2.9 Seedbeds

‘Safe sites’ for cedar germination, survival, and growth occur along a continuum of seedbed types depending on moisture availability (Cor-nett et al. 2000). The availability of a variety of seedbed types may be important for success-ful cedar regeneration (Cornett et al. 1997).

Cedar requires a moist substrate for success-ful germination. Northern exposures are often the most favourable for germination. Seeds will germinate and survive better on neutral

or alkaline soils, rotten wood, decayed litter, compacted moss, peat, and burned organic surfaces. On upland sites, mineral soil expos-ure is more favourable for cedar germination and survival given adequate seed source availability (Larouche et al. 2011). A thick layer of feathermoss and undecomposed litter may hinder germination and relatively fast-growing sphagnum moss may suppress a high propor-tion of seedlings (Johnston 1990; Sims et al. 1990). Cedar germinants growing on nurse logs or mineral soil, instead of forest floor litter, have a significantly higher chance of surviving to the end of the first growing season (Simard et al. 2003). Cedar seedlings also reproduce well on skid roads where the moss has been compacted and stays moist (Johnston 1977).

A thick cover of slash hinders seedling estab-lishment; a thin cover provides partial shade and improves germination results in contrast to areas with high light levels (Johnston 1977; Caulkins 1967). Litter-fall can smother slow-

Figure 2. Mature cedar cones ready to open. Photo by B. Fox.

7


growing seedlings (Simard et al. 2003).Decayed logs (Figure 3) and stumps (Figure 4) are reported to be preferred seedbeds for cedar germination and survival. A higher density and percentage of germinants occur

on these seedbeds than on other seedbed types, particularly when moisture availability is limiting and areas are undisturbed (Curtis 1959; Holcombe 1976; Cornett et al. 2000; Cornett et al. 2001). Among the possible benefits of decaying logs as seedbeds over other seedbed types (e.g., leaf litter, pits, and mounds) are that they provide moister and

Figure 3. Cedar natural regeneration on moss-covered, decaying cedar logs. Photos by B. Fox and M. Rhyner.

Figure 4. Decaying stumps provide good cedar seedbeds by improving moisture, nutrient, and light availability and reducing the opportunity for germinants to be covered by litter. Photos by N. Buda and M. Rhyner.

8


warmer growing conditions, higher light avail-ability, less opportunity for germinants to be covered by litter, an accumulation of bacterial-ly-fixed nitrogen, and higher concentrations of ectomycorrhiza (Cornett et al. 2001).

The best ‘nurse logs’ (Figure 3) are slightly elevated above the forest floor (+/- 9 cm) and are commonly covered by a thin layer of moss-es such as Heterophyllium, Pleurozium, and Brotherella. These mosses help to trap cedar seeds and maintain higher moisture levels (Holcombe 1976). Germination and survival of cedar may be influenced by the species of rotting log or stump (Figure 4) on which it germinates. Germination has been reported in one experiment to be higher on birch logs than cedar logs, possibly because the decom-position of the birch logs was more advanced, resulting in higher levels of moisture retention (Cornett et al. 2000).

However, decaying cedar logs may be safer sites for long-term survival since the higher nutrient levels available from decaying cedar logs encourage more rapid root elongation (Cornett et al. 2000). In addition, the type of canopy (e.g., birch vs. cedar) under which the seedlings are developing will influence seed-ling growth. Canopies that permit higher levels of light transmission to the forest floor will pro-mote seedling growth but may also contribute to seedling mortality if excessive transpiration rates and desiccation occur as a result of the higher light and temperature levels. Differ-ences in soil chemistry from the decomposition of leaf or needle litter from various species will also influence seedling growth rates (Cornett et al. 2001).

Although many benefits of decaying logs and stumps as seedbeds have been reported, no seedbed type may be unequivocally safe for germination under severe drought conditions (Cornett et al. 2000). Also, the higher densities of germinants growing on decaying logs are rapidly reduced by self thinning and the total area and distribution of decaying logs through-out an area is generally insufficient to create a

well-stocked cedar stand (Cornett et al. 1997).As a result, the occurrence or enhancement of a variable microtopography on a site can be a critical factor in determining the success of cedar regeneration (Miller et al. 1990; Miller 1995). On lowland sites, a primary cause of early seedling mortality is the annual flooding and drying cycle. Intermediate microsites on elevated hummocks or decaying wood may improve moisture conditions and improve ger-mination and early survival success. Activities during harvest and site preparation should be designed to protect or improve the frequency and distribution of these important micro-topographical features (Figure 5) (Miller et al. 1990).

2.10 Natural Disturbances

Cedar trees are very susceptible to fire dam-age, although fire is not as often a major threat on lowland sites (Sims et al. 1990). Cedar can regenerate well on burnt organic substrates if

Figure 5. Narrow harvest corridors with light slash and good cedar seedbed available. Photo by B. Fox.

9


a seed source remains after wildfire. Where fires are frequent, cedar components are likely to be absent, or are unlikely to be sustained. Cedar is relatively shallow rooted (Figure 6) and subject to windthrow and uprooting. This is particularly true for stands that have been partially cut and along stand edges (Godman 1958; Johnston 1977). Large trees and those with basal defects are most susceptible to wind damage (Johnston 1990).

Because of its dense foliage, cedar can fre-quently incur breakage or permanent bending and leaning from snow- and ice-loading (God-man 1958; Johnston 1990). On wet sites, im-peded drainage may restrict soil aeration and reduce cedar growth rates or kill entire stands (Schaffer 1996). Cedar roots are easily ex-posed, trampled by animals, and subjected to potentially lethal drying from fluctuating water tables. Recent plantings are particularly sus-ceptible to winterkill by dehydration (Schaffer 1996). Winter weather and drought can turn cedar foliage yellow or brown and can cause severe damage or death (Schaffer 1996).

Cedar is an important winter browse species for white-tailed deer (Odocoileus virginianus) and snowshoe hare (Lepus americanus). The presence of dense local deer populations may

be a major factor in preventing successful cedar regeneration (Johnston 1990; Davis et al. 1998; Larouche et al 2010). Although hare browsing has been documented (Johnston 1990; Larouche et al. 2011), the impact of hare browsing on cedar regeneration success is less consistent (Davis et al 1998).

Animal populations may fluctuate tremen-dously during the long time frame in which slow-growing cedar is susceptible to browsing, which increases the possibility that a cedar stand may be at risk from excessive browsing at some point during the regeneration phase (Miller et al. 1990). Wildlife cover and cedar regeneration are typically established close to each other when some harvest methods are used (e.g., strip and patch cuts, shelterwood, and group selection cuts), increasing the likelihood that regeneration may be browsed. Moose occasionally browse on cedar in winter (Sims et al. 1990).

2.11 Diseases

Despite cedar lumber having the reputation of being decay resistant, the heartwood of cedar trees is frequently attacked by fungi (Figure 7). The height of the decay column varies considerably between trees. Increased inci-

Figure 6. Cedar is shallow rooted; roots are vulnerable to decay. Photos by N. Buda and B. Fox.

10


dence of decay is associated with improved soil drainage (Hofmeyer et al. 2009b). Fruit-ing bodies are rarely evident on cedar stems, branches, and/or foliage.5 Woodpecker holes are often the first indicators of butt rot, disease and/or insect infestations (Schaffer 1996).

White stringy butt rot is caused by Poria sub-acida and affects mature stands growing on drier lowland soils. Balsam (brown) butt rot (Tyromyces balsameus) and red-brown butt rot (Phaeolus schweinitzii) are both cubical rots, commonly occurring in trees on drier parts of swamps and on knolls (Schaffer 1996). On these sites, white stringy rot or brown cubical rot often attack mature and damaged cedars. These trees subsequently become susceptible to carpenter ant colonization (Johnston 1977). Specific management practices have not yet been identified that would be able to deal ef-fectively with cedar decay.

Leaf blight (Fabrella thujina) and juniper blight (Phomopsis juniperovora) attacks are rare. They can cause premature browning and shedding of leaf scales, easily confused with normal browning in the fall (see Figure 2 in OMNR 1998).

2.12 Insects

Red and black carpenter ants and leafminers are the principle insect pests of cedar. Car-

5 R. Wilson, OMNR, Forest Program Pathologist, personal com-munication, 2009.

penter ants frequently attack partially decayed heartwood in living trees (Johnston 1977); in certain locations, anecdotal evidence suggests 20% of harvested trees show ant damage. Infested trees on swampy ground often lose merchantability from 1 m of stem length from the butt. On higher ground, loss may extend to the first 2 m of stem length from the butt (Craighead 1950).

Cedar leafminer is common and causes se-vere scorching of foliage. This leads to twig, branch, and/or tree death. From 2000 to 2010 in southeastern Ontario, cedar leafminer led to extensive tree mortality6 (likely amplified by drought conditions).

Aphids, root weevil, mites, and other borers (e.g., Semanotis ligneous) also occasionally attack cedar (Pirone 1978).

Specific practices to manage and control cedar insect pests effectively have not yet been identified.

3.0 SITE QUALITY AND GROWTH AND YIELD

The past status of cedar as an underutilized timber resource and a minor component of the forest industry in Ontario has meant min-imal effort has been invested in developing basic site quality evaluation tools and growth and yield models. Ontario Ministry of Natural Resources (OMNR) currently has projects underway to address this issue, including a large data collection program led by Northwest Science and Information (Corbett and McCaul 2010).

Site Index7 (SI) tables and related curves from

6 T. Scarr, OMNR, Provincial Forest Program Entomologist, personal communication, 2010.

7 Site Index - a quantitative value referring to total height of dominant / codominant trees at a specific reference age (usually 50 years) at breast height in Ontario. Trees used in estimating site index are typically free-growing and occur in undisturbed, well-stocked, even-aged, pure or single-species-dominated, older stands. Such stands must be moderate in stem density. Because of these limitations, site index is difficult to apply to

Figure 7. Heartwood rot in cedar. Photo by B. Fox.

11


the Lake States (based on forest survey data collected in the 1930s8) are presented in Ap-pendix A. These SI curves are anamorphic, which may limit their applicability9 if future study reveals polymorphic growth patterns. An SI conversion model has also been developed in the Lake States to estimate cedar SI from measurements of balsam fir SI (and vice-versa) on sites where they occur together. This conversion model has not been validated in Ontario.

The application of traditional site-quality evaluation tools, such as SI, may be very dif-ficult with Ontario cedar stands, particularly on boreal sites. Finding suitable “site” trees for estimating SI can be a challenge. Such trees need to have grown free of suppression after reaching breast height, and must not have vis-ible signs of damage, disease, or other defects interfering with height growth or preventing an accurate determination of age (Figure 8). In addition, SI models are typically derived from information from even-aged, pure stands. Many older, lowland cedar stands in particular are all-aged, and dominant/codominant trees, which might be considered for SI estimates, are likely to have been suppressed to some degree in the past. On upland sites, cedar often occurs in mixed stands, where competi-tion-induced suppression often occurs during juvenile growth (OMNR 1998). Cedar is able to tolerate long periods of suppression and still respond well to later release (Miller 1990), so it may not be apparent that potential SI trees have undergone an extended period of sup-pression.

All of this could limit the applicability of SI tools in assessing cedar growth potential. Work with other species in the province (e.g., Buda

uneven-aged, mixed-species stands – typical of cedar-domi-nated stands. Still, site index prevails in forestry as a common method of evaluating potential productivity, and is important both for estimating growth and yield and for supporting silvicultural decisions.

8 The nature of this data, number of samples, and types of sites sampled are unknown to the authors of this report.

9 Anamorphic (similar-shaped) SI curves are older and obsoles-cent; modern curves tend to be polymorphic, changing shape with different site qualities.

and Wang 2006), however, suggests SI could potentially still be used, with caution, in these types of stands.

Figure 8. Large, high-quality cedar with good form and growth. Photos by B. Fox.

12


Growth intercepts10 are used to estimate SI in younger, regenerating stands, but are sub-ject to similar limitations as SI tools. Growth intercepts for cedar are not currently available. Indirect methods11 can also be developed once basic SI models exist. These are less precise (but still useful) qualitative models such as ecosystem typing or plant indicators and may be used to give rough estimates of site quality useful for basic management decisions.

All of these growth and yield tools are import-ant to link site quality to yield predictions, assess whether a regenerating stand is de-veloping to meet management objectives, and assess silvicultural effectiveness.

3.1 Volume Tables

Standard volume tables can be used for lar-ger-scale planning exercises, but local volume tables are needed for reliable stand-level vol-ume determination.

New local volume tables for cedar in Ontario are currently under development. Corbett and McCaul (2010) have released a preliminary cedar volume table (Appendix B) based on re-cent stem analysis and permanent sample plot data from sites across boreal Ontario.

Older published tables are also available for cedar in Ontario. Honer’s (1967) standard vol-ume tables include equations and tabulated data for cedar, but are based on a compara-tively small sample of 187 trees from both On-tario and Quebec. Maurer’s (1993) local tree volume tables for northeastern Ontario include tables for cedar and also include information on sample ranges and handy, site-class cross-

10 Growth intercept models estimate SI from the mean annual height growth derived from the lengths of several (usually five) internodes immediately above breast height in juvenile stands that are less suited to the application of normal SI models and curves.

11 Indirect methods of SI estimation use relationships between Indirect methods of SI estimation use relationships between SI and other site factors, such as soil variables, to estimate SI in the absence of suitable site trees. If basic SI models can be derived for cedar, these tools could then be developed to extend the range of applicability and usefulness of the SI models in evaluating cedar growth and yield.

reference tables. The applicability of these tables to the northwest region has not been investigated. These tables may overestimate productivity on better northwest sites, but little is known about the actual distribution of sam-ple plots and whether all site types and SIs are represented.

3.2 Cull Estimation

Reliable cull tables and models that allow determination of cull as percentages of gross merchantable volume are also required to de-pict the actual amount of merchantable wood in a given stand. Cull estimates can allow the adjustment of local volume table figures to account for unusable wood, and help identify sites with potential for excessive waste.

There are no standard cull tables or models currently available for cedar in the northern regions. Based on historical scaling results, a provincial defect factor of 12.7% is applied to the gross merchantable volume of cedar deliv-ered to the mill12.

4.0 SILVICULTURAL PRACTICES

4.1 Silvicultural Systems and Regeneration Methods

The standard silviculture systems (i.e. clear-cut, shelterwood, and selection systems) may be used for cedar management under boreal conditions, with some limitations (Table 1). In addition, for added flexibility, a system using retention levels greater than that provided in even-aged silviculture systems (clearcut and shelterwood) but less than that provided in all-aged selection systems is included. The Silvi-culture Guide to Managing Spruce, Fir, Birch, and Aspen Mixedwoods in Ontario’s Boreal Forest (OMNR 2003) discusses this concept as “enhanced retention”, and for cedar, this

12 K. Widdifield, OMNR, Tenure and Measurement Co-ordina-tor, NWR, personal communication, 2008.

13


method has been formally described here as the reserve shelterwood silviculture system. Descriptions of the clearcutting, shelterwood and selection systems are given in the current silviculture guides (OMNR 1997, 1998, 2000, 2003). A description of the reserve shelter-wood system is provided below. The relation-ship between the various silviculture systems in terms of current cedar composition, stand structure objectives (even-aged or uneven-aged), regeneration (natural or artificial), and shelter requirements are given in Figure 11.

Reserve Shelterwood System

This modification is characterized by a rela-tively long regeneration period during which a portion of the old stand is retained for an extended period. The reserve trees comprise both dominant trees from the original stand as well as trees from lower crown classes that are capable of rapid growth once released. This approach is intermediate between even- and uneven-aged management. It involves the maintenance of two or more age classes through all or, at least 20 %, of the rotation. The reserve shelterwood system is an addi-tional system to the traditional clearcut, shelterwood and selection systems shown in the existing provincial silviculture guides. This system is targeted to situations where it is desired to deliberately retain all or some of the overstorey trees (see Franklin et al. 1997, 2002 for a discussion on variable retention) for more than 20% of the rotation age (oper-able age) to accommodate stand structure management objectives (Nyland 2002). This technique allows for an amount of residual tree retention that is between the amount allowed after clearcutting (generally <25% retention for full-light conditions) and the amount allowed for the selection system (generally >70% re-tention).

Reserve shelterwood also allows for a longer retention time than traditional shelterwood systems. As a minimum, trees are retained for more than 20% of the rotation age and some

or all of the retained overstorey trees may be retained long enough for them to succumb and become large snags. The decision on amount and length of time to keep the reserve trees depends on several biological and financial considerations; but to retain at least a two-aged structure, reserve trees would not be removed for at least one-half of a rotation (Ny-land 2002).

The reserve shelterwood system is particularly important as an addition to the selection sys-tem in Ecoregions 3E and 4E of northeastern Ontario. In these Ecoregions, higher humidity is associated with longer fire cycles, allowing extensive stands of uneven-aged, mid- and late-seral succession stage forests to evolve (Bergeron and Archambault 1993; Bergeron et al. 2001, 2004; Cyr et al. 2010; Grenier et al. 2005; Lefort et al. 2003). These forests have important ecological roles.

Late seral forests are characterized by many combinations of vertical and horizontal struc-tures, numerous large cavity trees, and abun-dant coarse woody debris (McCarthy 2001; Chen and Popadiouk 2002; Harper et al. 2002, 2003, 2005; Kneeshaw and Gauthier 2003). Since cedar stands are more commonly as-sociated with late-seral forests (Kneeshaw and Bergeron 1998), in order to sustain ecosystem function, a harvest system that maintains most or all of these attributes is needed while still allowing some cedar extraction.

The reserve shelterwood system maintains stand structure intermediate between even-aged and uneven-aged (Figure 9). For at least one-half of the rotation, enough legacy trees are retained to provide coarse woody debris inputs, and sustain mid- to late-seral stage habitat characteristics and regeneration cap-acity. Lower canopy cedar trees grow into the overstorey and the stand regenerates through seeding. To ensure effective representation of the original canopy, tree harvest must be spread over all diameter and quality classes. This maintains both the structural function and genetic diversity of the stand. As stems

14


die, become snags (Figure 10), and fall over, the structural complexity of the stand is main-tained.

4.2 Ecosites for Cedar Management

To date, cedar management has generally been assigned to broad classifications of low-land or upland sites. Currently, lowland cedar-dominated and cedar-leading sites (Low) in-clude the Northwest Region ecosite 37 (Sims et al. 1997) and the Northeast Region ecosites 9r and 13r. Upland cedar-dominated and cedar-leading sites (Up) include the Northwest Region ecosite 17 and the Northeast Region ecosites ES 9r (upland), 21, 20, 7c, and 7m. The new provincial ecological land classifi-cation (based on draft Banton et al. 2009) provides an opportunity to refine these site descriptions. In this new classification, the lowland ecosites where cedar is often a major component are:

B066 moist sandy to coarse loamy cedar - hemlock conifer

B115 moist silty to fine loamy to clayey cedar - hemlock conifer

B129 organic rich conifer swampB224 mineral rich conifer swamp

The upland ecosites often dominated by cedar are:

B013 very shallow dry/fresh cedar - hem-lock conifer

B025 very shallow humid cedar - hemlock conifer

B036 dry sandy cedar - hemlock conifer B051 dry/fresh sandy to coarse loamy cedar

- hemlock conifer B084 fresh clayey cedar - hemlock conifer B100 fresh silty/fine loamy cedar - hemlock

conifer

Cedar also occurs in a variety of related ecosites as a minor component of mixed spe-cies stands. Mixed species stands require special attention when managing for incidental species such as cedar. In Ecoregions 3E and 4E, cedar in mixed species conditions (espe-

cially when accompanied by balsam fir and white birch) and spruce-fir conditions are be-lieved to represent a late successional stage (Bergeron and Dubuc 1989; Kneeshaw and Bergeron 1998). Although a comprehensive inventory has not been done, it appears that cedar under these conditions is scattered throughout the stand either as individual trees or small clusters in an intimate mixture within the broader mixedwood or spruce-fir condition.

Under current operations, where cedar oc-curs as individuals or small clusters in a stand, they are considered incidental to the harvest and the stand is harvested according to the general silvicultural ground rule applicable to the dominant species and forest unit. This approach may lead to the loss or reduction of the cedar component of the stand. If the future stand condition includes an objective of maintaining these inclusions of cedar indi-viduals and clusters similar to the pre-harvest condition (e.g. in an intimate mixture pattern), then cedar-specific silviculture practices (e.g. renewal options and competition control meas-ures) need to be implemented specifically to these cedar inclusions. (see Table 1: Clearcut system – seed tree; and Table 2: Competition control).

4.3 Genetics and Management

As outlined in Section 2.6, information about cedar genetics is limited and sometimes con-

Figure 9. Typical structure of old growth cedar stands with multiple size and age classes. Photo by B. Fox.

15


tradictory. As a result, somewhat tempered, precautionary approaches should be used to manage cedar genetic resources as follows:

In accordance with current policy, Ontario’s 1. tree seed zones must be used to limit the movement of tree seed and planting stock. This will ensure that artificially regener-ated stock is suited to local climate and site conditions. Seed zones should also be used as genetic resource management zones since each one represents an ap-propriate spatial scale for promoting the long-term viability of the species (Joyce et al. 2001).Small isolated populations should be 2. regenerated with local seed or, at a min-imum, from the seed zone in which it oc-curs. A stand is considered isolated if it is separated by more than one kilometre from the nearest similar stand (OMNR 1998). In natural regeneration methods, trees with 3. desirable phenotypes such as good height, straight-grain, and small branch diameter should be left to parent the next generation (Joyce et al. 2001). For partial cut systems, as a general guid-4. ing principle, the recommendation from OMNR (1998) should be followed; a min-imum of 100 widely-spaced trees, capable of mating and producing viable seed, should be retained to ensure an effective breeding population.

Repeated cycles of diameter-limit cuts, that 5. is, the removal of all trees in a stand above a specified diameter, will tend to remove the most vigorous trees because they reach the threshold diameter more rapidly. Genetic degradation would be most likely when the most vigorous trees were re-moved before producing progeny (OMNR 2001). Hence, high-grading or diameter-limit cutting should not be permitted.Group seed tree cuts that retain small 6. patches of trees separated beyond effect-ive cross-pollination distances should be avoided, i.e., distances greater than 30 m (Joyce 2009; Cornett, et al. 2001).To minimize the potential for inbreeding, 7. planting programs should use carefully selected seed from high quality trees from the local seed zone and from well-dis-persed natural stands (OMNR 2001). To help maintain genetic diversity, advance 8. growth from both layering and seed origins should be protected during harvesting and renewal operations.

5.0 SELECTING A SILVICUL-TURE SYSTEM AND HAR-VEST METHOD

In general, the selection of appropriate man-agement strategies for a particular site should include the following considerations (Miller 1990; OMNR 1997):

silvics of desired species• associated species and their silvics• seed dispersal potential for crop and • competitive speciespost-harvest microclimate as affected • by the shape, size, and orientation of the canopy and openingsrelative intensity of competition from • undesirable vegetation and availability of control measuresrisk of natural disturbance from surface • and ground fire, water table or flow changes, potential insects/disease, or

Figure 10. Leaning cedar trees are an important part of stand structure. Photo by B. Fox.

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17


wind and ice damage as influenced by harvest methods.importance of stand for wildlife habitat • or natural heritage valuesmanagement objectives•

5.1 Pre-harvest Assessment

In addition to these general considerations, a pre-harvest assessment of the planned har-vest area should be conducted to document specific stand and site conditions used to se-lect between management options (i.e. Table 1).

1. Physical characteristics of the sitedetermine upland or lowland ecosite • classification and document soil condi-tions, such as texture, depth of organic or mineral horizons, moisture regime, and calcareousnessassess potential impact of harvest on • seasonal water table fluctuations and surface flow patternsevaluate topography and its influence • on microenvironment (i.e., elevation, slope, and aspect) and potential modifi-cations from harvest methods.assess potential availability of suitable • seedbeds.

2. Cedar stand location, size, and distribution determine ease of access for harvest • and follow-up treatments.assess size of stand to determine an • appropriate silvicultural system and harvesting techniquedetermine proximity of the stand to • other stand types that are significant for other non-timber purposes, such as water management or wildlife habitat (see OMNR 2010)

3. Stand structureevaluate to determine an even-aged or • uneven-aged stand structuredetermine distribution and abundance • of cedar and other tree species in the overstorey and understorey (as ad-

vance growth) to evaluate harvest op-tions.evaluate size, age, and quality of over-• storey trees to determine their capaci-ties for regeneration, and suitability for various uses.

4. Site productivitydetermine from suitable site index trees • or other site indicators

5. Associated plant speciesevaluate regeneration opportunities • and/or competition problems that may result from harvest options and identify the need for pre-harvest treatments, site preparation, and/or tending treat-ments.

5.2 Silviculture Practices For Eastern White Cedar in Boreal Ontario: Introduction to Table 1

The silvicultural practices suggested for man-aging eastern white cedar in boreal Ontario are outlined in Table 1. These practices are applicable where cedar regeneration is a silvi-culture objective for any stand to be harvested. These include:

stands (identified as polygons on the • forest resource inventory) that are cedar-dominated (80% or more cedar composition) or cedar-leading (<80% cedar and cedar is the most abundant species), and the target is to regener-ate back to cedar;mixed species stands where cedar • is a minor component (other species are dominant or leading) but there are clear cedar-dominated or cedar-leading clusters >400 m², and the target is to regenerate the clusters back to cedar;mixed species stands where cedar is • in an intimate mixture as individuals or small clusters (<400 m²) throughout the stand, and the target is to maintain or enhance the cedar presence; andany sites where cedar is to be intro-• duced.

18


The silvicultural treatments are intended for site conditions where cedar will grow product-ively and may be managed on a sustainable basis. Active management of cedar generally applies to sites when the site index at 50 years breast-height age (SIBHA50) for cedar exceeds 8 m.

The silvicultural systems and harvest methods listed as options for cedar management in Table 1 follow the framework of Nyland (2002).

The following information is provided for each silvicultural system and harvest method out-lined in Table 1:

Silvicultural System – Harvest Method

Application (general conditions appro-1. priate for its use) Objectives 2. Prerequisites (specific conditions that 3. should be in place before its used) Harvest and Renewal Approach4.

5.3 Operational Considerations for Promot-ing Cedar: Table 2

Table 2 (Operational Considerations for Pro-moting Cedar) provides additional information regarding the application of the techniques mentioned in Table 1 for cedar management in boreal conditions.

Table 2 is organized under the following head-ings:

Preharvest treatmentsHarvesting

Regenerationa) General b) Lowland c) Upland d) Seed e) Vegetativef) Artificial

Site Preparation

Competitiona) Generalb) Lowland Sitesc) Upland Sites

Tending

The direction provided in Table 2 may be in-corporated into the development of silvicultural ground rules for any stands where the cedar component is to be maintained or enhanced. Unique challenges in regenerating cedar may require that cedar be given the primary con-sideration in developing regeneration strat-egies for the stand, in particular, where cedar occurs in intimate mixture with other species.

5.4 Monitoring

Conditions under which boreal cedar manage-ment treatments occur, and the results, should be documented and monitored to improve the state of knowledge and future success. The most efficient way to increase silviculture ex-pertise, particularly for a stand type that is a minor component of harvest and silvicultural programs, is to adopt a standardized monitor-ing approach and coordinate data compilation and analysis provincially.

Cedar management activities should be in-corporated into local silvicultural effectiveness monitoring programs. Pre-harvest conditions and treatment documentation should be de-tailed enough to help determine the reasons for success or failure.

Large scale (e.g. provincial) coordination of standardized monitoring is encouraged to maximize information available to practition-ers. Sample tally sheets (adapted from Bid-well et al. 1996) for conducting standardized pre-harvest assessments and developing silvi-culture prescriptions are shown in Appendix C. As well, a standardized monitoring procedure has been developed to document post-treat-ment stand and site conditions and track cedar silviculture success (Appendix D).

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Figure 12. Narrow skid trail with light ground disturbance and same area seven years later with abundant hardwood competition. Photo by B. Fox.

Figure 13. Cedar seeded in on hair cap moss (Polytrichum commune) on a disturbed skid trail with optimum partial shading. Photos by B. Fox and M. Rhyner.

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Figure 16. Upland cedar natural regeneration growing well seven years after harvesting. Photo by B. Fox.

Figure 15. Cedar 1-0 Mutlipot 45’s planting stock. Pho-tos by B. Fox.

Figure 14. Upland mixedwood site with cedar clump and abundant hardwood competition. Photo by B. Fox.

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Figure 17. Examples of narrow corridors with optimum 50% shading for cedar natural regeneration. Photos by B. Fox.

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Table 1. Silvicultural practices for eastern white cedar in boreal Ontario.24

Silvicultural PracticesClearcut System – Seed Tree

Application: This method is not appropriate in cedar-dominated and cedar-leading stands.

The risk of blowdown of individual cedar or small groups of cedar is high. Appropriate where the decision to clearcut a mixed species stand has been

made, primarily on upland sites. A lack of experience in regenerating cedar as scattered individuals or patches

means monitoring for both regeneration and windthrow of seed trees is necessary.

Objective: To maintain or enhance the cedar component when it occurs individually or in small

patches in mixed species stands.

Prerequisites: An assessment to ensure an adequate amount and distribution of advance growth

should be required prior to harvest. Favourable form, high quality, wind-firm, dominant or co-dominant seed trees of

seed-bearing age; individual trees may not be wind-firm when root development has been impeded (e.g., on extremely wet or very rocky sites) or the height/diameter ratio exceeds 70:1.

Adequate distribution of favourable seedbeds.

Harvest and Renewal Approach: Seeds are primarily wind-dispersed and travel 45-60 m under normal conditions

(Miller 1990, OMNR 1998). In order to maintain cedar in the regenerating stand, cedar seed-tree focal points (wind-firm individual cedar trees, groups of cedar trees, or groups of cedar with other species) should be retained post-harvest. Seed trees should be left standing as they occur, either as pairs or individuals, to reflect the original distribution of cedar in the stand.

An unharvested distance of one tree-length (based on dominant tree height) should be maintained around the cedar. The mature canopy buffer serves to reduce birch and aspen regeneration to promote cedar natural seeding within and adjacent to the cluster, and to reduce blowdown of the cedar.

Windthrow within the buffers may create mineral soil exposure but mechanical/manual site preparation will likely be required to augment the number of suitable seedbeds.

The decision to harvest a portion of cedar trees within groups is based upon the number of trees within a group and the distribution of cedar throughout the stand. The intent is to leave sufficient seed trees that will function as a seed source for a sufficient period of time. If cedar seed trees are uniformly intermixed throughout a stand, then up to one-half of the cedar trees within a clump may be harvested as long as the residual trees are good quality seed trees and at least the same size as those harvested. An extraction trail located opposite to the prevailing wind direction can be used through the buffer to harvest the available cedar trees. If cedar seed trees are isolated then the tree/clump along with a one tree-length buffer should not be harvested.

The amount and distribution of advance growth should be assessed before harvest and, where significant, protected to assist regeneration; for example by using carefully designed harvest trails (OMNR 1997).

Sites should be inspected after harvest to ensure that there are a sufficient number

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of well-distributed, suitable microsites for seed germination. Site preparation may be required to provide adequate microsites. Release treatments may also be needed to promote cedar regeneration.

Since cedar is susceptible to common herbicides in use (e.g., glyphosate), patches of planted cedar would require manual tending or directed herbicide application. An alternative would be to leave large enough patches of unharvested canopy cover (two tree-length diameter) to reduce aspen regeneration where cedar can either be regenerated through planting or seed tree. These patches also serve to maintain some of the old forest condition associated with late successional mixedwood stages.

Clearcut System – Strip and Patch Cuts

Application: Applicable to cedar leading or dominant stands. Not appropriate where an uneven-aged stand structure is desired. Applied primarily to lowland sites where shelter for natural seeding on moist

seedbeds is not necessary. Upland sites with drier seedbed conditions require shelterwood methods.

Strip cuts should be used in stands in which cedar is well stocked and well distributed, and patch cuts should be applied to stands where the distribution of cedar is less uniform.

Objectives: To protect fragile sites by minimizing stand entries and encourage natural

regeneration; and To create even-aged stand conditions in regenerated strips or patches.

Prerequisites: Abundant, well-distributed cedar seed trees in adjacent, uncut portions of the stand; The site must have potential for adequate distribution of high quality seedbeds after

harvest, otherwise appropriate treatments will be necessary to create suitable seedbeds.

Consider treatments to reduce the incidence and productivity of vigorous competitors.

High soil pH is essential for regeneration from seed (Miller 1990, OMNR 1998, Cornett et al. 1997, 2000, 2001). More acidic soils should be regenerated using the Clearcut - Advance Growth or artificial regeneration methods below.

Harvest and Renewal Approach: When advance regeneration constitutes a significant component of the regenerating

stand, it should be protected during harvest. As harvesting occurs, ‘preharvest’ competition control measures may be

implemented in adjacent uncut strips or patches scheduled for harvest in the next cycle (see Table 2).

Strip cutting (trees removed in alternate or progressive strips): o Subsequent strips may only be harvested when cedar regeneration in

adjacent strips has reached free-to-grow standards. o Strip width should not exceed the seeding distance of cedar, which is

estimated at twice the height of the cedar trees. If a cedar seed source is readily available from both sides of the harvested strip, the width of the strip may be somewhat larger but should not exceed three times the height of the seed trees (Godman 1958, Johnston 1977, OMNR 2003). Machine access

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and manoeuvrability should also be considered in determining strip width. o Strips should be orientated perpendicular to prevailing wind direction

(generally westerly) which facilitates seed dispersal and reduces risk of wind damage.

o Some modification to this orientation may be considered. A northerly exposure is the most favourable for reproducing cedar (Johnston 1977). Strips oriented east-west would maximize the northerly exposure along one strip edge but may result in unacceptable blowdown risk. Terrain analysis should be used to determine strip orientation.

o Final strip should be cut in two stages as a uniform shelterwood, i.e., regeneration and final cut (Johnston 1977), or artificially regenerated.

Patch cutting:o Patches provide a higher edge-to-area ratio than strip cuts and may

maximize natural regeneration from adjacent seed sources. o Patch width should be less than or equal to three times the height of the

seed trees (OMNR 1998); the coverage and frequency of these patches is dependent on the cedar distribution in the stand.

o Final patch is cut in two stages as a uniform shelterwood, (i.e., regeneration and final cut (Johnston 1977), or artificially regenerated.

Clearcut System – Advance Growth

Application: Applicable to cedar leading or dominant stands. Used primarily for lowland ecosites. Not appropriate where an uneven-aged stand structure is desired. Large black spruce wetland complexes in some areas of the boreal forest have

scattered, smaller pure lowland cedar stands that occur within them. The surrounding stands would typically be harvested using techniques, such as Careful Logging Around Advance Growth that protect and take advantage of advance growth.

Objective: To remove the overstorey, protect advance growth, and regenerate an even-aged

stand. This has the potential to shorten the rotation length (OMNR 1997).

Prerequisites: Pre-harvest densities of advance growth that are sufficient to meet minimum

stocking standards (OMNR 1997).

Harvest and Renewal Approach: Harvest should only occur while sites are frozen. Where advance growth alone does not meet site occupancy requirements, groups

of seed trees should be left to provide a seed source, particularly adjacent to high-traffic machine trails. Refer to Clearcut System - Seed Tree method above.

Shelterwood System – Uniform Shelterwood

Application: For cedar leading or dominant stands. Not to be applied in site regions 3E and 4E. Primarily for upland ecosites where seedbed microsites have the potential to dry

out.

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Not appropriate where an uneven-aged stand structure is desired. Applied when cedar is uniformly distributed throughout the stand.

Objectives: To create even-aged stand conditions. To create favourable sheltered microclimate conditions for cedar establishment and

growth by reducing moisture deficits on dry sites and suppressing growth of shade intolerant competitors.

To regenerate the last strip of a strip cut.

Prerequisite: A stand well-stocked with cedar that is uniformly distributed. Careful selection of removal trees (marking by a certified tree marker) for the

regeneration cut.

Harvest and Renewal Approach: Two-cut harvest (regeneration cut and final cut). Regeneration cut targeting 40-60% crown closure. Poor quality cedar, hardwoods and other undesirable species should be targeted for

removal in the regeneration cut. Residual overstorey trees provide seed and improve the microclimate in order to

improve regeneration success and limit the regeneration of shade-intolerant competitors (e.g., alder, aspen).

Final harvest occurs when regeneration has met free-to-grow standards.

Shelterwood System – Strip Shelterwood

Application: For cedar leading or dominant stands. Not to be appled in site regions 3E and 4E. To be used where deer and hare populations will not impact regeneration success

because wildlife cover and browse are kept in close proximity with this method.

Objective: To create shaded microclimate conditions from uncut strips.

Prerequisites: Preparatory treatments to reduce reproductive potential of vigorous hardwood

competitors in the leave strips and patches should be considered (see Preharvest Treatments: Table 2).

Cedar should occur uniformly throughout the stand or in local concentrations sufficient to harvest strips.

Harvest and Renewal Approach: Similar to strip clearcuts except that strip widths are narrower, not exceeding half

the height of the trees in uncut strips (e.g., 10 m strips as opposed to 20 m strips for strip clearcut); narrower strips increase shade in harvested strips.

Machine access and manoeuvrability in strips must be carefully considered and planned; specialized harvesting equipment may be required to limit damage to regeneration and trees in uncut strips.

Strip orientation should be selected with regard to prevailing wind direction (which affects both blowdown risk and seed dispersal) and aspect (that would influence the

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amount of shading occurring in the harvested strip throughout the day); subsequent strip cuts should be scheduled when cedar regeneration in adjacent strips has reached free-to-grow standards.

Final strip is cut in two stages as a uniform shelterwood, i.e., regeneration and final cut, (Johnston 1977), or artificially regenerated.

Shelterwood System - Reserve Shelterwood

Application: May be applied to cedar leading or dominant stands or mixedwood stands with a

cedar component. Appropriate where the maintenance or creation of mid- to late-successional stand

characteristics is desired. Particularly suitable for site regions 3E and 4E.

Objective: To maintain ecosystem function of uneven-aged mid- to late-seral stages of succession at required levels across the landscape for wildlife habitat, biodiversity, or other values (OMNR 2003). Associated stand characteristics are horizontal and vertical structural diversity, and the presence of large trees.

May be applied in mixedwood conditions to promote cedar regeneration while suppressing birch and aspen competition by providing 50% shade.

Prerequisites: Suitable for uneven-aged and even-aged stands to maintain or create an uneven-

aged stand structure. Certified tree marking is required to ensure stand degradation does not occur. May be applied to a wide range of conditions.

Harvest and Renewal Approach: Tree marking is required with the following marking guidelines:

o trees marked for removal should be from all species and merchantable size classes.

o after harvest, the same proportion of desired species and merchantable size classes that occurred in the original stand should remain. “Good quality trees”, medium- to large-sized cedar trees with high merchantable value (e.g., straight, clear bole - no spiral, no rot), must be retained. Retaining “good quality trees” will help ensure that their seed will produce trees with desirable merchantable attributes.

o Selection of trees for harvest and retention through marking should result in improved stand quality and promote removal of undesirable species.

Post-harvest overstorey canopy should be retained to provide 50% or less of full sunlight.

Strip shelterwood techniques (alternating retained-harvested strips half a tree length wide) may be applied but the retained trees are not removed for at least 50% of the rotation (operable age).

Selection System – Group Selection

Application: Used for cedar leading or dominant stands. Applied to maintain or create uneven-aged stand conditions.

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Objective: To maintain or create uneven-aged conditions similar to natural stand structure

resulting from a management decision to emulate long fire return intervals.

Prerequisite Conditions: On sites where competition may inhibit regeneration, preparatory treatments should

be carried out to reduce regeneration of vigorous competitors (especially hardwoods and shrubs) in the unharvested leave areas.

A commitment to mark removal trees by certified tree markers. Feasible long-term access is needed. Requires a long term commitment to maintain records and continue recording and

tracking stand treatments to meet objectives.

Harvest Approach: Group openings should not exceed half of the average tree height in the stand

(Kneeshaw and Bergeron 1998). Openings should be distributed uniformly throughout the harvest block, and should

not exceed 20% of stand area during each cycle (OMNR 1998). The cutting cycle is likely to exceed 30 years, and will depend on the rate of

regeneration establishment, growth and desired future stand structure (Schaffer 1996; OMNR 1998).

Veteran trees must be retained (OMNR 1998, 2010). As group selection requires multiple stand entries, it should be limited to smaller

scale operations. Prevention of damage to sites, residuals, and advance growth should be stressed. Balsam fir advance regeneration must be reduced or eliminated where it is a

significant competitor for cedar regeneration. This harvest method, involving repeated stand entries, provides an opportunity to use ‘preharvest’ competition control methods in areas that will be harvested in the next cycle (see Table 2).

Discouraged Practices

Even-aged silviculture practices (clearcut, shelterwood) are not appropriate for regions associated with a humid boreal climate, in particular Ecoregions 3E and 4E, if cedar is the target future stand condition under an emulation of natural disturbance directive.

There is high potential for high-grading with the single tree selection system. Conventional clearcutting in cedar-dominated or cedar-leading stands is not

appropriate at this time. Since there has been little research or management experience on eastern white cedar in boreal Ontario, a precautionary approach of gradual removal of the canopy with accompanying regeneration assessment has been adopted.

To avoid site damage, harvest or mechanical site preparation on wet or deep organic sites that are not frozen is not appropriate.

For sites dominated by microsites prone to drying out during the summer (e.g.,hummocks, logs, and moss), reliance on natural regeneration from seed is not advised.

Full-tree logging in partial canopy removal operations (shelterwood or selection systems) is not appropriate where there is risk of damage to residuals.

Broadcast application of herbicides is not advised at present, as cedar susceptibility to them is uncertain. Glyphosate labels list Thuja spp. as “vegetation controlled”, meaning it could be killed or damaged.

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Table 2. Operational considerations for promoting cedar.

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Preharvest Treatments When the occurrence of significant amounts of competition is anticipated once

the stand is harvested (e.g. from speckled alder, mountain maple, balsam fir, trembling aspen, white birch and balsam poplar), preharvest treatments should be considered to reduce opportunities for severe competition to develop.

In some instances, only a few mature competitors may occur in the uncut stand (e.g. 10% composition of aspen), but may generate substantial competition if allowed to reproduce in the harvested area (Johnston 1977).

Preharvest treatments may include felling, girdling or the application of herbicides to remove competitors and/or reduce their reproductive potential.

When harvest is occurring for harvest methods that require repeated stand entries (i.e. progressive strip cuts; group selection), competition control treatments could effectively be conducted in adjacent uncut areas using equipment and labour already on site.

Preharvest treatments add to costs, but may prevent or reduce more expensive treatments in the future and may be the key to renewal success (Miller 1990; Johnston 1977).

Harvesting Lowland sites are subject to rutting and compaction, so harvesting should be

scheduled for the winter months when sites are completely frozen to minimize site damage and protect advance growth. Harvest equipment should be confined to repeatedly-used trails spaced as widely as possible (OMNR 1997). See OMNR 2010 for details.

Failing to protect advance growth may result in prolonged regeneration delays or failures.

Harvesting can enhance microtopography, which may create suitable elevated seedbeds to improve cedar germination and survival.

When small cedar stands occur as part of a larger mixedwood or spruce-fir polygon, limited access and economic considerations generally make multiple entries for harvesting and renewal prohibitive. Therefore, multi-entry dependent seed tree, shelterwood, and selection systems cannot be applied operationally in these areas.

Partial harvest prescriptions are dependent on specialized operator training to ensure appropriate implementation and prevent damage to sites and residual trees.

As new techniques are being developed, certified tree marking is required for partial harvest systems to ensure that stand objectives are met.

The potential for leaving large volumes of cull (poorer quality) stems in older stands and partial harvests means that the risk of high-grading is great. Harvest controls and monitoring should be implemented to ensure that stand quality is not degraded (i.e., maintain or improve quality).

Regeneration

a) General Moderate amounts of slash can provide shade and microrelief important for

seedling establishment but large amounts can cover suitable seedbeds, inhibit regeneration, and provide herbivore habitat e.g., hare (Miller 1990).

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b) Lowland Highly productive lowland sites in Michigan indicate very long natural recruitment

periods, in excess of 25 years (Miller 1990, 2005); maintaining advance growth may shorten these periods (OMNR 1998). It is likely that silvicultural ground rules for cedar will have to account for these longer regeneration delays than are customary for other lowland conifers in boreal Ontario.

Some lowland sites are prone to seasonal flooding, resulting in risk to cedar regeneration (OMNR 1997).

Advance growth should be assessed prior to harvest. Where it can contribute a proportion of the regeneration, it should be protected if possible during harvesting. Advance growth may be used as the primary means to regenerate lowland sites and reduce regeneration periods, particularly very wet, less productive cedar sites (OMNR 1998).

c) Upland Renewal on upland sites may be hampered by lack of appropriate seedbeds,

unsuitable moisture or pH, susceptibility to droughts, and excessive competition (Miller et al. 1990).

d) Seed Observations suggest that natural seeding is a common regeneration method on

lowland, intermediate quality sites. Fluctuating groundwater levels have been implicated in seedling mortality, either

by desiccation or drowning (Miller 1990). Germination success and seedling survival is improved on sites with microtopography that provides suitable drainage and yet maintains an adequate supply of moisture (Miller et al. 1990, Cornett et al. 2000, 2001).

Compacted, moist moss on machine trails can provide suitable seedbeds for cedar (Fowells 1965).

Good seedbeds for cedar are consistently moist and warm throughout the growing season.

Seeds germinate on a variety of moist substrates but establish themselves on only a few (Johnston 1990), i.e., on bare mineral substrates, moss mats and downed, decaying logs (Pretgitzer 1991). Pre-seeding assessments should consider this in determining whether further site preparation is required prior to seeding.

Regeneration from seed on drought-prone sites or conditions is often not successful as microsites tend to dry out.

Compacted fine-textured soils (resistant to seedling root penetration) are also poor seeding choices.

In open conditions, cedar seed disperses 45-60 m, although effective seeding distance may be less. Therefore, strip cuts must be narrow or patch cuts must be small for seed-based natural regeneration to succeed.

On highly competitive upland sites, the success of seeding is doubtful without site preparation and a vegetation management plan.

Broadleaf litter fall can smother germinants.

e) Vegetative Vegetative regeneration (layering) is the primary method of natural regeneration

on poor lowland cedar sites (Schaffer 1996). Trees of layered origin tend to have sweeping stems and may be less desirable

for posts and timber (Miller 1990).

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Layer-origin cedar stands tend to be scattered, with dense clumps of trees; these provide excellent wildlife habitat (Miller 1990).

Vegetative reproduction is considered to be more shade tolerant than seedlings (Schaffer 1996).

On upland sites, layering is less common than on lowland sites; therefore, seeding is likely to be the primary mode for natural regeneration on upland sites.

f) Artificial Specific conditions for ensuring consistent success in seeding cedar are

unknown. Little information has been published on recommended seeding rates and methods. Though broadcast seeding of some conifers has proven to be a successful regeneration method, Heitzman et al. (1999) noted natural cedar stands required 10-20 years of continuous seed inputs to establish fully stocked regeneration. Direct seeding, with appropriate competition control, may be more successful as seed can be directly applied to suitable microsites. Multiple seedings may still be required.

Small quantities of cedar have been planted operationally in boreal Ontario over the past 20 years. Planting may prove effective in restoring cedar on competitive sites, provided there is adequate shade for seedling establishment and competing vegetation is managed (Miller et al. 1990).

Planting cedar is an option to augment the natural regeneration (advance growth or seed) in any of the silviculture practices.

There is currently little published information regarding cedar planting prescriptions. Schaffer (1996) summed up the few recommendations available as follows:

o high initial planting densities encourage height growth, good form development, and natural pruning;

o wider spacings may result in multiple stems, larger crowns, and reduced timber production;

o height growth is slow initially, averaging about 8 cm annually during the first few years.

Site Preparation Site preparation should either maintain or enhance variable microtopography to

increase the number of suitable seedling microsites. Manual site preparation while planting (screefing) is preferred over mechanical

methods to both minimize the potential for site damage on lowland sites and preserve existing microtopography.

Mechanical site preparation may be required on sites where a level microtopography could limit successful cedar regeneration. Several mechanical site preparation methods have been tested with varying results in other jurisdictions (Lanasa and Zuidema 1991). Mounding has been shown to have the greatest potential for overcoming raised water tables and can be successfully done in winter (Miller 2005). Large mounds are susceptible to summer drying though, and careful testing and monitoring is needed in Ontario to verify the usefulness of this method.

On lowland cedar sites, site preparation should be scheduled for the winter months when the site is completely frozen.

Prescribed burning has been occasionally carried out in cedar stands, and Miller (1990) suggests it is a promising technique with the following benefits: reduction of slash and undecomposed mosses, increased surface temperature, and increased soil pH. Burning can also reduce hardwood competition and advance

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growth of competing conifers (Lanasa and Zuidema 1991, Miller 1990, OMNR 1997). Broadcast burning or wildfire must be fairly severe to expose favourable mineral soil seedbeds (Johnston 1990).

Competition

a) General Although shade tolerant cedar seedlings tend to be taller in half-to-full sunlight,

shoots and roots are heavier in full light (Johnston 1990). Cedar can withstand severe suppression for many years and may respond well

to release at nearly any age (Johnston 1990; OMNR 1998). Although moisture is often the most critical factor during the first years of

establishment, ample light is necessary for continued seedling development (Johnston 1990).

Shrubs associated with cedar have, in general, the same shade tolerance as cedar; partial canopy removal will not eliminate this competition.

There is little certainty about cedar susceptibility to herbicides presently used in Ontario. Glyphosate product labels, for example, list Thuja spp. under the category of “vegetation controlled”. Where cedar advance growth is to be retained, chemical site preparation is not appropriate. Chemical site preparation holds promise for controlling competition before artificial seeding or planting.

Directed release treatments, such as motor manual cleaning with direct chemical application, are suggested for vegetation management to prevent herbicide damage to adjacent seed trees, uncut cedar stands, or regeneration.

Glyphosate can be applied with various directed spraying methods such as: Ezject® (injection of glyphosate capsules); liquid application to stumps (e.g., with brush saws); or back pack spraying of leaves.

Triclopyr can be used effectively with methods such as basal squirt application.

b) Lowland Sites Moderate woody shrub competition from maple, alder, and red raspberry should

be expected following harvest or other disturbances. Shrub species such as mountain maple can provide low levels of beneficial

cover, but if they were to occur at high densities they would be severe competitors. Competition from lowland species that are commonly abundant on these sites, such as speckled alder, can be significant (Racey et al. 1996).

Grasses, sedges, and cattails are often abundant after severe site disturbance (OMNR 1997).

Fast-growing sphagnum mosses can sometimes out-compete seedlings (OMNR 1997). This may be less of a concern for layer-origin trees (Miller 2005).

Black spruce, balsam fir, and tamarack are common. These species may be promoted by silvicultural practices to regenerate cedar. This may be a concern if their densities are high enough to compete with cedar.

c) Upland Sites Balsam fir can be a dominant understorey competitor in cedar stands. Site preparation may stimulate seedbank competition. Where mechanical and chemical site preparation are combined to create suitable

cedar seedbeds, the timing for effective competition control needs to be determined. The scenario may follow the sequence: 1) mechanical site preparation; 2) a period where the seedbank competition is allowed to germinate and grow; 3) chemical site preparation; and 4) monitoring to determine if

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adequate cedar seedlings are regenerating. For seed tree and shelterwood silviculture systems on richer sites, vegetation

management may be required through chemical site preparation (ground spraying equipment) and/or manual control.

Partial overstorey shade can be used to reduce regeneration of undesirable competitive balsam poplar and aspen (Groot et al. 2009) or stands could be cleaned of these species prior to harvest (Miller et al. 1990).

In areas with frequent hot, dry periods, partial shade may be needed to reduce losses from drought and herbaceous competition (Johnston 1990).

Tending Cedar response to thinning is good at nearly any age (Fowells 1965); 85-year-old

stands in Michigan have demonstrated substantial positive growth responses to thinnings (Miller 2005).

Thinning can achieve a positive growth response on productive, well-drained lowland sites with good subsurface (telluric) water flow (OMNR 1998, Miller 2005).

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Kayahara, and Y. Bergeron. 2010. A simple Bayesian Belief Network for estimating the proportion of old-forest stands in the Clay Belt of Ontario using the provincial forest inventory. Can. J. of For. Res. 40: 573-584.

Davis, A., K. Puettmann, and D. Perala. 1998. Site preparation treatments and browse protection affect establishment and growth of northern white-cedar. USDA, NC For. Exp. Sta., St. Paul, MN. Res. Pap. NC-330. 9p.

Fowells, H.A. (comp.). 1965. Silvics of forest trees of the United States. U.S. Dept. of Agric., Agric. Handbook 271. Washington, DC. 762 pp.

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Habeck, J.R. 1958. White cedar ecotypes in Wisconsin. Ecology 39(3): 457-463.

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35


For. 26: 21-27.

Hofmeyer, P.V., L.S. Kenefic, and R.S. Sey-mour. 2010. Historical stem development on northern white-cedar (Thuja occiden-talis L.) in Maine. North. J. Appl. For. 27: 92-96.

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36


Workshop, North Bay, ON, December 1990. 13pp.

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Miller, R.O. 2005. Northern white-cedar re-generation and silviculture: lessons from Michigan’s Upper Peninsula. Invited lec-ture at OMNR Ecology and silviculture of eastern white cedar workshop. Dryden, Ontario, 2005.

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spruce, fir, birch and aspen mixedwoods in Ontario’s boreal forest. Version 1.0. OMNR, Queen’s Printer for Ontario. 286 pp. + Appendices.

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37


Schaffer, W. W. 1996. Silvicultural guidelines for the eastern white cedar. OMNR, SR STTU, Tech. Rep. TR-006. 62 p.

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Sims, R.A., H.M. Kershaw and G.M. Wick-ware. 1990. The autecology of major tree species in the North Central Region of Ontario. COFRDA report no. 3302. NWO-FTDU Tech. Rep. no. 48. 126 pp.

Sims, R.A., W.D.Towill, K.A. Baldwin, P.Uhlig and G.M. Wickware. 1997. Field guide to the forested ecosystem classification for northwestern Ontario. OMNR, NWST, Thunder Bay, Ont. Field Guide FG-03. 176 pp.

White, R.G., C.L. Bowling, W.J. Parton and W.D. Towill. 2005. Well-spaced free-grow-ing regeneration assessment procedure for Ontario. OMNR NWSI Tech. Manual TM-007. 38 pp. + appendices.

38


APPENDIX A

Eastern White Cedar Index

33

11.0 APPENDICIES

APPENDIX A

Eastern White Cedar Site Index

Age 6 8 10 12 14 16 18 2020 3.10 4.13 5.16 6.20 7.23 8.26 9.30 10.3325 3.74 4.98 6.23 7.47 8.72 9.96 11.21 12.4530 4.33 5.77 7.21 8.65 10.09 11.53 12.98 14.4235 4.87 6.50 8.12 9.74 11.37 12.99 14.62 16.2440 5.38 7.17 8.96 10.76 12.55 14.34 16.13 17.9345 5.85 7.80 9.74 11.69 13.64 15.59 17.54 19.4950 6.28 8.37 10.47 12.56 14.65 16.75 18.84 20.9355 6.68 8.91 11.14 13.36 15.59 17.82 20.05 22.2760 7.05 9.41 11.76 14.11 16.46 18.81 21.16 23.5265 7.40 9.87 12.33 14.80 17.26 19.73 22.20 24.6670 7.72 10.29 12.86 15.44 18.01 20.58 23.16 25.7375 8.01 10.69 13.36 16.03 18.70 21.37 24.04 26.7180 8.29 11.05 13.81 16.58 19.34 22.10 24.86 27.6385 8.54 11.39 14.24 17.08 19.93 22.78 25.63 28.4790 8.78 11.70 14.63 17.55 20.48 23.40 26.33 29.2695 8.99 11.99 14.99 17.99 20.99 23.98 26.98 29.98

100 9.20 12.26 15.33 18.39 21.46 24.52 27.59 30.65

Site Index

0.00

5.00

10.00

15.00

20.00

25.00

30.00

20 30 40 50 60 70 80 90 100

Total Age (years)

Tota

l Hei

ght (

met

res)

)1. 59801. 397 (1 0. 53510 Ae SH

Data Source: Laidly (1979) after Gevorkiantz (1957). Prepared from forest survey data for lake states) collected during 1936-1946; unknown number and range of samples.

Note: curves are anamorphic and not constrained to go through index height at index age.

Data Source: Laidly (1979) after Gevorki-antz (1957). Prepared from forest survey data for lake states) collect-ed during 1936-1946; unknown number and range of samples.

Note: curves are anamorphic and not constrained to go through total height at index age.

33

11.0 APPENDICIES

APPENDIX A

Eastern White Cedar Site Index

Age 6 8 10 12 14 16 18 2020 3.10 4.13 5.16 6.20 7.23 8.26 9.30 10.3325 3.74 4.98 6.23 7.47 8.72 9.96 11.21 12.4530 4.33 5.77 7.21 8.65 10.09 11.53 12.98 14.4235 4.87 6.50 8.12 9.74 11.37 12.99 14.62 16.2440 5.38 7.17 8.96 10.76 12.55 14.34 16.13 17.9345 5.85 7.80 9.74 11.69 13.64 15.59 17.54 19.4950 6.28 8.37 10.47 12.56 14.65 16.75 18.84 20.9355 6.68 8.91 11.14 13.36 15.59 17.82 20.05 22.2760 7.05 9.41 11.76 14.11 16.46 18.81 21.16 23.5265 7.40 9.87 12.33 14.80 17.26 19.73 22.20 24.6670 7.72 10.29 12.86 15.44 18.01 20.58 23.16 25.7375 8.01 10.69 13.36 16.03 18.70 21.37 24.04 26.7180 8.29 11.05 13.81 16.58 19.34 22.10 24.86 27.6385 8.54 11.39 14.24 17.08 19.93 22.78 25.63 28.4790 8.78 11.70 14.63 17.55 20.48 23.40 26.33 29.2695 8.99 11.99 14.99 17.99 20.99 23.98 26.98 29.98

100 9.20 12.26 15.33 18.39 21.46 24.52 27.59 30.65

Site Index

0.00

5.00

10.00

15.00

20.00

25.00

30.00

20 30 40 50 60 70 80 90 100

Total Age (years)

Tota

l Hei

ght (

met

res)

)1. 59801. 397 (1 0. 53510 Ae SH

Data Source: Laidly (1979) after Gevorkiantz (1957). Prepared from forest survey data for lake states) collected during 1936-1946; unknown number and range of samples.

Note: curves are anamorphic and not constrained to go through index height at index age.

18

16

14

12

10

8

6

H = 1.973 (S1) (1 - e -0.01535 (Age))1.0895

39


APPENDIX B

Preliminary Volume Table for Eastern White Cedar in Boreal Ontario (Corbett and McCaul 2010).

Eas

tern

Whi

te C

edar

Vol

ume

Tabl

esD

iam

eter

cm

(2.5

cm

cla

ss)

Cou

nt =

*(11

)*(

16)

*(19

)*(

15)

*(12

)*(

12)

*(20

)*(

14)

*(26

)*(

16)

*(5)

*(5)

*(3)

*(4)

*(2)

*(2)

(n =

182

tree

s)10

12.5

1517

.520

22.5

2527

.530

32.5

3537

.540

42.5

4547

.550

Ht (

.5 m

cla

ss)

Ave

rage

s0.

028

0.05

00.

082

0.12

30.

176

0.17

60.

300

0.38

30.

468

0.57

70.

685

0.78

60.

936

1.05

71.

211

1.35

01.

561

40.

022

0.02

24.

50.

023

0.02

35

0.03

10.

024

0.03

85.

50.

033

0.02

60.

040

60.

043

0.02

70.

042

0.06

16.

50.

046

0.02

80.

044

0.06

47

0.05

80.

030

0.04

60.

067

0.09

17.

50.

061

0.03

10.

048

0.07

00.

095

80.

077

0.03

20.

051

0.07

30.

099

0.12

98.

50.

080

0.03

40.

053

0.07

60.

103

0.13

49

0.10

90.

035

0.05

50.

079

0.10

70.

140

0.12

90.

218

9.5

0.12

60.

057

0.08

20.

111

0.14

50.

134

0.22

610

0.17

50.

059

0.08

50.

115

0.15

00.

140

0.23

40.

284

0.33

710

.50.

182

0.06

10.

087

0.11

90.

155

0.14

50.

243

0.29

40.

349

110.

271

0.06

30.

090

0.12

30.

161

0.15

00.

251

0.30

30.

361

0.42

40.

491

0.56

411

.50.

301

0.09

30.

127

0.16

60.

155

0.25

90.

313

0.37

30.

437

0.50

70.

582

120.

456

0.09

60.

131

0.17

10.

161

0.26

70.

323

0.38

50.

451

0.52

30.

601

0.68

30.

771

0.86

40.

963

12.5

0.47

10.

099

0.13

50.

176

0.16

60.

275

0.33

30.

396

0.46

50.

539

0.61

90.

704

0.79

50.

891

0.99

213

0.71

90.

102

0.13

90.

182

0.17

10.

284

0.34

30.

408

0.47

90.

555

0.63

80.

725

0.81

90.

917

1.02

21.

132

13.5

0.77

50.

143

0.18

70.

176

0.29

20.

353

0.42

00.

493

0.57

20.

656

0.74

60.

842

0.94

41.

052

1.16

514

0.79

70.

147

0.19

20.

182

0.30

00.

363

0.43

20.

507

0.58

80.

675

0.76

70.

866

0.97

11.

081

1.19

814

.50.

819

0.15

10.

197

0.18

70.

308

0.37

30.

444

0.52

10.

604

0.69

30.

788

0.89

00.

997

1.11

11.

231

150.

841

0.15

50.

203

0.19

20.

316

0.38

30.

456

0.53

50.

620

0.71

20.

809

0.91

41.

024

1.14

11.

264

15.5

0.90

40.

208

0.19

70.

325

0.39

30.

468

0.54

80.

636

0.73

00.

831

0.93

71.

051

1.17

01.

297

160.

927

0.21

30.

203

0.33

30.

403

0.47

90.

562

0.65

20.

749

0.85

20.

961

1.07

71.

200

1.33

016

.50.

950

0.21

90.

208

0.34

10.

413

0.49

10.

576

0.66

80.

767

0.87

30.

985

1.10

41.

230

1.36

317

0.97

30.

224

0.21

30.

349

0.42

30.

503

0.59

00.

684

0.78

60.

894

1.00

91.

131

1.26

01.

396

17.5

1.04

40.

219

0.35

80.

433

0.51

50.

604

0.70

10.

804

0.91

51.

033

1.15

81.

290

1.42

918

1.06

80.

224

0.36

60.

443

0.52

70.

618

0.71

70.

823

0.93

61.

057

1.18

41.

319

1.46

218

.51.

150

0.37

40.

453

0.53

90.

632

0.73

30.

841

0.95

71.

080

1.21

11.

349

1.49

519

1.17

50.

383

0.46

30.

551

0.64

60.

749

0.86

00.

978

1.10

41.

238

1.37

91.

528

19.5

1.25

90.

473

0.56

20.

660

0.76

50.

879

0.99

91.

128

1.26

51.

409

1.56

120

1.28

50.

483

0.57

40.

674

0.78

20.

897

1.02

11.

152

1.29

11.

439

1.59

420

.51.

375

0.58

70.

688

0.79

80.

916

1.04

21.

176

1.31

81.

469

1.62

721

1.40

30.

597

0.70

20.

815

0.93

41.

063

1.20

01.

345

1.49

81.

660

21.5

1.49

90.

716

0.83

00.

953

1.08

41.

224

1.37

21.

528

1.69

322

1.52

90.

730

0.84

70.

972

1.10

61.

248

1.39

91.

558

1.72

622

.51.

632

0.86

30.

991

1.12

71.

271

1.42

61.

588

1.75

923

1.66

30.

879

1.01

01.

148

1.29

51.

452

1.61

81.

793

23.5

1.85

61.

170

1.32

01.

479

1.64

81.

825

241.

890

1.19

01.

343

1.50

61.

678

1.85

924

.52.

104

1.53

31.

708

1.89

225

2.14

11.

560

1.73

81.

925

25.5

2.37

91.

958

262.

419

1.99

226

.52.

795

272.

841

40


APPENDIX C

Pre-Harvest Assessment/Silviculture Prescription Form

43

Cedar Pre-Harvest Assessment/ Silviculture Prescription

Date: Plot #:

Region: District: Twp/Basemap/FRI Map#: Management Unit:

SFL/License #: Stand #: UTM Zone: Easting: Northing: Gross Area (ha):

Forest Ecosystem Classification Overstorey (BAF2 prism)Species Ce FRI Ecosite: FRI Stand Description:

DBH (cm) Ecosite Code: Substrate Code Height (m) Remarks: Density (st/ha)

Site Live Crown (%)

Canopy PositionLandform: Slope Position:

Age (years)Terrain: Slope%: Notes:

Shrub Layer (3.99 m radius plot)Aspect: Other:

Species

Soil Cover (%) Height (m) Moisture Regime/Drainage: Humus Form:

Competition Concerns:Soil Texture: Organic Matter

Depth (cm): Advance Regeneration (3.99 m radius plot)

Species Ce Depth to Mottles/ Gleying (cm):

Depth to Restrictive Layer (cm): Height (m)

Density (st/ha) Condition

Subsurface (Telluric) Water Flow Indicators:

Site Prone to Flooding/Drying?:

Notes:

Site Quality for Cedar Cedar Microsite Inventory (3.99 m radius plot)Microsite Type # Microsite Type #Site Index (BHA@50 years): Assessment Method:

Logs (>10 cm diameter) Stumps (>10 cm diameter)Hummocks (>20 cm ht) Other:Suitability for Cedar Management:

Notes:

Forecast At Establ. At FTG At Harvest 1: Species2: 1: Density

(st/ha) 2: 1: DBH (cm) N/A 2:

Other Values/Objectives:

1: Height (m) N/A 2: 1: Age (years) N/A 2:

1:Volume(m3/ha) N/A N/A 2:

First Nations Values to Maintain or Enhance:

Stand Ready for Harvest? Rationale for harvest/deferral:

Harvest Start (season/year) Finish (season/year)

Rationale for season (if applicable):

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Silvicultural System: Logging Method:

Constraints: Volume expected (m3/ha):

Special Conditions (reserves, etc.): Costs ($/ha):

Species used: Species Left:

Access:

Cedar specific concerns and limitations: Rationale:

Preferred Alternative Method

Season/year Microsite Objective

ConstraintsCosts ($/ha)

Rationale

MethodSeason/year

Species/stock Target Density

Costs ($/ha) Rationale

MethodSeason/year(s)

Objectives Costs ($/ha) Constraints

Rationale

Survey (type/year)

RelatedException

MonitoringResearch Program

Prescription Writer (print name)

Approver (signature) RPF#

Page 2 of 2 – Cedar Silviculture Prescription

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APPENDIX D

Monitoring Procedure to Document Post-Treatment Stand and Site Conditions and Track Cedar Silviculture Success

Cedar Regeneration Monitoring Assessment Field Methods

Gordon Kayahara1, R.G. White2, and Erik Klassen3

Step 1: Traverse the block boundaries and stratify the area

Traverse the area boundaries and, if necessary, stratify the area based upon different sites or different types of seed source (Figure 1). Blocks ,or strata, suitable for the cedar regeneration monitoring assessment have a cedar seed source that is within at least 100 m of assessment plots. Strata within a block will be sampled separately (Figure 2).

Step 2: Calculate the sample size and map plot locations

Based upon the Well-Spaced Free-Growing (WSFG) manual (White et al. 2005), calculate the sample size for each stratum with one modification based upon the maximum number of plots (for areas ≤10 ha sample - 31 plots; for areas >10 ha sample - 31 plots plus 1 additional plot for each ha). The sample size is calculated for the harvested portions of a block; for example, if a 20 ha block is harvested in corridors the sample size is determined for the 10 or 15 ha that have been harvested. Use an offset systematic grid (Figure 3a) set perpendicular to the harvest corridors, if present (Figure 3b).

Step 3: Moisture regime determination

Using the new ecological land classification system, determine the soil moisture regime for the stratum.

Step 4: Locate the plot centre

Locate the plot centre on the block. The center of this plot serves as a reference point for the overstorey components, the seed tree components, and establishment of the WSFG assessment plots (Figure 4). The overstorey plot can overlap with an unharvested corridor/edge but both WSFG plots are located entirely in the harvested area.

Step 5: Overstorey measurements

The overstorey plot has a circular radius of 11.28m (400 m²). Every tree with diameter greater than 10 cm is measured 1.3 m above the point of germination (diameter at breast height) and recorded by species. The average height and a visual estimate of % live crown (based on the OMNR Growth and Yield Program PSP and PGP Reference Manual, OMNR 2008) of each of these species are recorded.

Step 6: Seed source

Record the type of seed source (Figure 1), distance and direction to the closest seed sources within 100 m. Seed source numbers can vary from 1 (stand edge) up to 3 (dispersed seed trees). The canopy closure at plot center is taken.

1 Northeast Science and Information Section, Timmins, ON

2 Northwest Science and Information Section, Kenora ON

3 Northeast Science and Information Section, Timmins, ON

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Step 7: Suplot Locations

Two regeneration assessment plots will be established such that their circumferences touch at the center of the overstory assessment plot. Therefore, the center of each regeneration assessment plot should be 2.26m away from the center of the overstorey assessment plot. The two regeneration assessment plots should be positioned so that a line connecting their center would cross the center of the overstorey assessment plot. This line should generally be placed perpendicular to the direction of the systematic grid (Figure 4). The subplot centers are located entirely within the harvested portion of the stand, thus subplots are located at least 2.26 m away from the edge of an uncut portion of the stand (Figure 5).

Step 8: Seedbed composition

Each subplot has a radius of 2.26 m (16 m²). Estimate the seedbed composition coverage (%). Make special note if there is the presence of Polytrichum and/or Dicranum mosses (indicators of previously exposed mineral soil).

Step 9: Well-Spaced Free-Growing assessment

Using the Well-spaced Free-growing Regeneration Assessment Procedure for Ontario (White et al. 2005), conduct a WSFG regeneration assessment. Height classes are: class 1, 30-70 cm; class 2, 80-200 cm; class 3, >200 cm. Cedar is the target species but all other trees species are acceptable.

Step 10: Cedar regeneration assessment

Count the total number of seedlings in the 0-14 cm and 15-29 cm classes. For each height class pick a representative tree for age determination, estimate the dominant origin (seed or layer), estimate the dominant substrate at the base of seed origin seedlings, and note the dominant moss associated with the regeneration (distinguish feather mosses from the mineral soil indicators Polytrichum/Dicranum species).

Step 11: Subplot 2 assessment

Repeat Steps 8-10 for Subplot 2.

Step 12 (optional):

If the assessed area is located where future access will be maintained, consider converting some of the plots to permanent silviculture plots. A random selection of up to six individual cedar seedlings from each of the five height classes will be numbered and pinned using pigtails, and individual height, condition, and seedling origin recorded. The two subplots will be combined.

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Potential cedar seed tree defined generically as the overstory trees (>10 cm)

100 m

100 m 100 m 10-30 m

Dispersed Edge

Clumped and individual Corridor

Figure 1. Areas can be assigned to the following generalized seed source types: Dispersed, edge, clumped, individual, or corridor.

Dispersed

10-30 m

Corridor

Potential cedar seed tree defined generically as the overstory trees (>10 cm)

Figure 2. Three strata are shown based upon harvest pattern and spe-cies. The sample area for the corridor type (left) is only the harvest corridors. The sample area for the dispersed type (right top) is the entire stratum. Each stratum is treated as a separate area with sample size deter-mined separately for each stratum. The stratum lacking cedar (right bottom) is not sampled.

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Plot location

(A)

(B)

Figure 3. Use an offset systematic grid (A) set perpendicular to the harvest corridors, if pres-ent (B).

Overstory plotRadius 11.28 m

2 WSFG plotsRadius 2.26 m

Systematic line direction

Plot centre

Figure 4. Plot layout once the plot centre is located. The overstorey plot is 11.28 m (400 m²) with two “dumbbell” located WSFG plots of radius 2.26 m (16 m²). The direction of the “dumbbells” is perpendicular to the systematic line direction.

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Systematic line direction

Stand edge

Harvested portion

Standing living trees

Figure 5. The overstorey plot can be located within an unharvested corridor or edge but the two WSFG plots are located entirely within the harvested portion.

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Buda et al. 2011 CNFER IP-005 44

CEDAR REGENERATION MONITORING ASSESSMENT TALLY SHEET

Surveyors: Date:Page #: Total pages:

Stand Information Block No. Stratum No. Area (ha) Plot Numbers: Ecodistrict: Location:Silviculture System Harvest Method Harvest Year and Season: Site Preparation Type and Year Regeneration Method Species Planted: Vegetation Management Type and Year(s) Information Source

Soil and Site Description Forest Floor Thickness (LFH) EffectiveTtextureDepth to: Bedrock Stratified (Y/N)

Mottles Calcareous (Y/N)Gley

Organic Soil Von Post Moisture Regime

Notes:

48

Buda et al. 2011CNFER IP-005 45


Surveyors: Date:Page #

Plot Information Block Number: Stratum Number: Plot Number: GPS: UTM Zone:

Overstorey: Composition Description

Species DBH Species Average Height Average % live crown

Seed Source: Type: Distance: Type: Distance: Direction: Direction

Type: Distance: Direction:

Canopy closure Notes:

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Plot Information Page #

Block Number: Stratum Number: Plot Number:

SubPlot 1 Seedbed Composition (% coverage) Exposed Mineral Soil OtherLeaf & Needle Litter (LF) Downed Woody Debris Humus (H) Class I Water/Temporary Flooded Class II Rock Class IIIPolytrichum/Dicranum Moss Class IV Other Feathermoss Class V Sphagnum Moss

Well-Spaced Free-Growing Regeneration Assessment Total Number of Stems

Height Class* Species 1 2 3

Number of Well-Spaced Stems

Number of WSFG Stems

Double Sweep Species

Competing Species Average Height (cm) % Cover Woody

Herbaceous

Grasses, Sedges

Cedar Regeneration Assessment Height Class

(cm) Total Number Average Age Origin (Seed

or layer) If seed: origin

substrate Associated Moss

species 0-1415-29 *30-70 Height Class 180-200 Height Class 2>200 Height Class 3

Notes:

50

Buda et al. 2011CNFER IP-005 47


Plot Information Page #

Block Number: Stratum Number: Plot Number:

SubPlot 2 Seedbed Composition (% coverage) Exposed Mineral Soil Downed Woody Debris Forest litter Class I Water/Temporary Flooded Class II Rock Class IIIPolytrichum/Dicranum Moss Class IV Other Class V

Well-Spaced Free-Growing Regeneration Assessment Total Number of Stems

Height Class* Species 1 2 3

Number of Well-Spaced Stems

Number of WSFG Stems

Double Sweep Species

Competing Species Average Height (cm) % Cover Woody

Herbaceous

Grasses, Sedges

Cedar Regeneration Assessment Height Class

(cm) Total Number Average Age Origin (Seed

or layer) If seed: origin


species 0-1415-29 *30-70 Height Class 180-200 Height Class 2>200 Height Class 3

Notes:

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Permanent Silviculture Plot Information Block Number: Stratum Number: Plot Number: GPS: UTM Zone:

Combined SubPlots 1 and 2 Cedar Regeneration Assessment Tree Number Height Condition Origin (Seed

or Layer) If seed: origin


species

Notes:

Documents

Buda et al. 2011 CNFER IP-005 005 Centre for Northern ... · i. Buda et al. 2011 CNFER IP-005. FOREWORD. This technical report is intended to provide information to planning teams