Laminated Root Rot Forest Health Stand Establishment Decision Aid

Extension Note CONDENSED TITLE BC Journal of Ecosystems and Management British Columbia’s Coastal Forests Laminated Root Rot Forest Health Stand Establishment Decision Aid

Rona Sturrock1, Stefan Zeglen2, and Jennifer Turner3

Introduction

Laminated root rot (Phellinus weirii) is the most prominent root disease of Douglas-ﬁr in coastal coniferous forests and is endemic throughout its host’s range in British Columbia. The disease spreads primarily via root contact and can attack and gradually kill trees throughout their life cycle. It can lower stand volume by 40–70% on infected sites and acts as a stand-altering disturbance agent. The retention of infected stumps and residual trees (via partial cut- ting) can perpetuate the incidence of laminated root rot in a regenerating stand by leaving material on site to act as reservoirs of disease. To mitigate disease impact, a good understanding of the distribution and biology of P. weirii is necessary. The cedar form of P. weirii, which is responsible for a butt rot in western redcedar, is not covered in this extension note. The Stand Establishment Decision Aid (seda) format has been used to extend information on various vegeta- tion and forest health concerns in British Columbia. This decision aid summarizes information that relates current management regimes to the spread and effects of laminated root rot. The ﬁrst page provides general information, hazard ratings for some of the biogeoclimatic zones and subzones of the Coast Forest Region, and silvicultural considerations for laminated root rot. The second page outlines the growth and yield implications and other effects and associations of the disease. This page also includes a valuable resource and reference list to provide readers with more detailed information. Reference material that is not available on-line can be ordered through libraries or the Queen’s Printer at: http://www.qp.gov.bc.ca

Acknowledgements The preparation and publication of this decision aid was supported by the British Columbia Ministry of Forests and Range through the Forest Investment Account–Forest Science Program.

KEYWORDS: forest health, forest management, laminated root rot, Phellinus weirii, root disease management.

Contact Information 1 Research Scientist, Canadian Forest Service, Paciﬁc Forestry Centre, 506 West Burnside Road, Victoria, BC V8Z 1M5. Email: [email protected] 2 Forest Pathologist, B.C. Ministry of Forests and Range, Coast Forest Region, 2100 Labieux Road, Nanaimo, BC V9T 6E9. Email: [email protected] 3 (formerly Extensionist, Ecosystem Productivity, Forrex) Gartner Lee Ltd., Sperling Plaza, 6400 Roberts Street, Suite 490, Burnaby, BC V5G 4C9. Email: [email protected]

ARTICLE RECEIVED: May 6, 2005 ARTICLE ACCEPTED: September 1, 2006

JEM — VOLUME 7, NUMBER 3 Published by FORREX Forest Research Extension Partnership Sturrock, R., S. Zeglen, and J. Turner. 2006. JBritishEM — VColumbia’sOLUME #, coastalNUMBER forests: # Laminated root rot Forest Health 41 Stand Establishment Decision Aid. BC Journal of Ecosystems and Management 7(3):41–43. url: http://www.forrex. org/publications/jem/ISS38/vol7_no3_art5.pdf STURROCK, ZEGLEN, AND TURNER - - - is an alterna dbh fir, subalpine hemlock, Western Western redcedar, yellow-cedar, and yellow-cedar, redcedar, Western and fir, amabilis grand fir, Douglas-fir, pine and lodgepole pine white Western less-susceptible species regeneration. for less-susceptible is at harvestlum when and machinery personnel already are on-site. not well quantified. are disease dynamics root on retention) high-quality with sites sloping, gently on only removal, machinery where without soils amenable can work risk of of stumps Only degrading species need be susceptible soils. removed. it removal, stump Like inoculum. method reducing for tive high-quality to is best suited Douglas-fir grand or fir sites with slopes of loam soil sandy to less than 30% and sandy textures. This may susceptibility. lower have or immune that are an on species a rotation for mean planting less productive site. infected and killed within be years. colonized a few may stump infected Highly Susceptible: mountain hemlock Susceptible: Moderately Engelmann spruce and spruce, Sitka Tolerant: Immune: or Resistant broadleaf species disease. its a formal determine survey to conduct of disease, root distribution and severity. be stratified may a buffer) (including fined infection centres A high untreated. left are areas while treatment adjacent for render may widely or dispersed distribution, incidence, strategies management some unworkable. of the selection removal or stumps) of (e.g., reduction other, • inocu reduce mechanically time to The most cost-effective • variable The (e.g., effects silvicultural of systems alternative Silviculture Considerations Regeneration/Establishment SITE PREPARATION • and root stump through reduction, inoculum Consider • of Push-falling Douglas-fir 78 cm up to PLANTING • species consider is not an option, removal inoculum When • naturally growing species or near an planted Susceptible Host Information • • • • Harvest Considerations • of root assess the presence a harvest plan, developing Before • If than 5% occurrence a visual more indicates assessment • de clearly Disease distribution is important; aggregated, • strategies inoculum either based usually on are Treatment - - , , - ) form ecm ecm . - 1 may not be found with limited excavation. not be with found excavation. limited may Phellinus weirii ecm near the root collar. near the root ecm ) zone, subzone, and variant subzone, ) zone, bec spicuous to be useful for disease detection or assessment/survey. or disease detection be for useful spicuous to hosts. and susceptible stumps or trees infected 10 years. so do it may roots, and large stumps infested large, In phytically. should tree or stump infected any such, As years. more 50 or for although of this risk source inoculum, a potential be considered time. will over decline for an explanation of an explanation for Biogeocli Classification matic Ecosystem ( abbreviations. field observations only. looking for When at least a portionon of roots. infected con and then beginning soil collar at the root remove carefully roots. lateral along outward tinue over associated Often rings annual along separates (delamination). form in pits with masses of setal that may this are hyphae brown Setal are hyphae cracks openings tissues. or in affected in any or diagnostic of the stain sunlight, direct In ofis also a good indicator the disease. weeks. a few just after fade may incon or rare too are but of stumps, and uprooted fallen trees (1991) and Pojar See Meidinger Douglas-fir ratings for and grand are based on Hazard fir and are • adjacent between contact root through The disease spreads • of an average live trees larger the onset of symptoms, After crown • sapro live to continues the pathogen die, trees infected When a 1 • ( mycelia purplish or ectotrophic tawny, Grey-white, • of Evidence • formed of crusty is often hyphae dark layer brown A protective, • pits and easily small oval displays with decay advanced Wood • tops, stump visible fresh on often stained wood, brown Reddish • the underside bodies can form on Fruiting of rot root laminated Hazard Rating -

are actually two closely related related closely actually two are ; the species on western redcedar, redcedar, the species western on ; P. weirii P. . P. sulphurascens P.

Uprooted coastal Douglas-fir with the characteristic Uprooted coastal Douglas-fir root rot. root wad caused by laminated Canadian Forest Service, Pacific Forestry Centre Forestry Pacific Service, Forest Canadian and loss of and discoloration height needles, growth, damaging other however, crops; cone stress-induced cause similar may condition an environmental or agents of examination Close is recommended. roots symptoms. from a few trees to several hectares. Several factors will factors Several hectares. several to trees a few from whetherdetermine disease distribution is aggregated or dispersed. when Douglas-fir fill in openings infected created often die. rot with root laminated evident years. 10–20 become in plantations after agreed upon. The species on Douglas-fir is proposed to be The species Douglas-fir to on is proposed agreed upon. called weirii P. openings surveys and stand when canopy reconnaissance observed. are and fallening dead trees root a compact creating off collar the root break to close wad.” “root ball or (e.g., Douglas-fir). (e.g., forms ofcedar been not yet have them names for the correct species, Laminated Root Rot – British Columbia’s Coastal Forests Columbia’s British – Root Rot Laminated • reduced include symptoms of rot Crown root laminated • within Douglas-fir mature Disease centres stands range • redcedar) western (e.g., conifers or hardwoods Resistant • of groups Small symptomatic usually trees and dead • during ground detected first is often rot root Laminated • often roots major decayed falls tree over, an infected When Characteristics of Susceptible Stands • stands of Managed species highly susceptible • stands infected. Preceding General Information • agree that the Douglas-fir and Although taxonomists

42 JEM — VOLUME 7, NUMBER 3 LAMINATED ROOT ROT FOREST HEALTH STAND ESTABLISHMENT DECISION AID f , , - orrex F m 0 http://www. Rep. No. 17. No. Rep. : : url frda Forest Research Research Forest g f , 3340 Pilot Knob Road, Road, 3340 Pilot Knob , Forest Research Extension Research Forest ORREX l aps F http://www.fs.fed.us/pnw/pubs/ : : orrex F [email protected] url © 2006 © m -349. -349. and other native root pathogens as de pathogens root native and other http://warehouse.pfc.forestry.ca/pfc/5434.pd : : pnw-gtr url Phellinus weirii http://warehouse.pfc.forestry.ca/pfc/3916.pd http://www.for.gov.bc.ca/hfd/pubs/Docs/Srs/SRseries.ht http://bookstore.cfs.nrcan.gc.ca/detail_e.php?recid=3538 : : : : : : url url url f http://www.pfc.forestry.ca/pathology/rootd/laminated_e.htm Her Majesty the Queen in right of Canada, Natural Resources Canada, Canadian Canadian Canada, Resources Queen the Majesty in rightHer Natural of Canada, : : 1488-4674. Information in this publication may be reproduced in electronic be reproduced or print in this publication Information may form 1488-4674. for.gov.bc.ca/tasb/legsregs/fpc/fpcguide/root/roottoc.ht url Phytopath. Rev. Ann. America. North Western in ofterminants structure and process forest 38:515–539. Minn. Paul, St. B.C. Victoria, For., Min. and B.C. Serv. For. Can. 2nd ed. British Columbia. 6. No. Ser. Rep. Spec. 16. No. Note Transfer Tech. B.C. Victoria, 3. No. Leafl. Pest For. Bull. Resour. Can. and For. Serv. For. Agric. gtr349/gtr349a.pd Serv., Victoria, B.C. B.C. Victoria, Serv., B.C. Victoria, Code, Practices Forest guidebook. disease management Root © 2006 © 2006 Province of British and Service, Columbia, © Forest Extension Partnership. issn activities provided and not-for-profit of the worksource that the use training, for in educational, commercial in whole or in part, for reproduction of this work, However, acknowledged. is fully or redistribution written resale, use, requires permission from and all copyright this purpose, contact:Partnership For holders. Managing Editor, BC Kamloops, Avenue, 235 1st 702, Suite or email V2C 3J4, Canadian Forest Service, Pacific Forestry Centre. Forest pathology Web site: Laminated root rot. rot. root Laminated site: pathologyWeb Forest Forestry Centre. Pacific Service, Forest Canadian 2000. Goheen. and E.M. E.M. Hansen, of diseases. Compendium conifer 1997. Lewis. and K.J. E.M. Hansen, in damage forest to Field guide 2001. Pollard. A. and Westfall, J. Allen, E. Ebata, T. J., Henigman, B.C. Victoria, For., Min. B.C. of British Ecosystems Columbia. 1991. Pojar. and J. D. Meidinger, Serv., For. Can. of and push-falling. stumping diseases by Management root 2000. R. Sturrock, B.C. Victoria, Ser., For. Can. of rot root Douglas-fir. Laminated 1994. Garbutt. and R. R. Sturrock, Dep. U.S. America. North in western rot root Laminated 1995. Sturrock. and R.N. W.G. Thies, Resource and Reference List and Reference Resource For. Can. diseases of tree Common BritishColumbia. 1996. Wallis. and G. Morrison, D. E., Allen, 1995. Lands and Parks. Ministry Ministry ofBritish Columbia and B.C. of Environment, Forests - - in - - -

P. weirii P. ) is added oaf 2 value of 2 value be to applied 5%) may and its interactions with organisms. other oaf P. weirii P. xm1 and xm2 subzones. This value is currently 7.5% and represents 7.5% and represents is currently This value xm1 and xm2 subzones. 2 value for all Douglas-fir-leading types all Douglas-fir-leading for 2 value old in the than 10 years greater is a disturbance agent that creates ecosystem and stand structural ecosystem that creates is a disturbance agent . oaf 3 cwh mm and growing space for less susceptible conifers and immune hardwoods and shrubs. hardwoods and immune conifers less susceptible for space growing and ecological succession. diversity disease). root and blackstain Armillaria rot root eases (e.g., discounted value (not lower than the default than the default (not lower value discounted Douglas-fir types of less years 10 or age. of the incidence logging enhance nor Salvage will reduce neither value. nomic a logged stand. Phellinus weirii gaps that provide canopy creates It and wildlife habitat. debris, woody coarse diversity, 40–70% through mortality, growth reduction, and butt rot. Infected trees are susceptible susceptible are trees Infected rot. and butt growth reduction, mortality, 40–70% through and insect damage. windthrow to 1.4 million m the default to cdf a practices, disease management root better for account To diseases. all root losses to levels iflevels than 60% of highly or moderately susceptible. more are the trees the possibility to This is due that as of more or is dispersed 15% through the stand. rot root soon be windthrown. may trees such trees; willymptomatic trees infected as crop be retained the mortality it causes. rehabilitating the plantation by starting over after an inoculum reduction treatment or or treatment reduction an inoculum after starting the plantation by over rehabilitating This kind of is a method of with species. rehabilitation replanting resistant by last resort. disease spread. barriers root increase to cies to reduce to age) stand on 15 m depending 5 to (from buffer an adjacent and disease centres ofspread the fungus. tive. Avoiding the planting of susceptible species near infected stumps is only effective if the planting of effective species is only stumps near infected susceptible Avoiding tive. beforehand. identified be can stumps reliably such and dying dead trees. with scattered • can affect plant community rot root laminated by of The removal Douglas-fir overstorey • on has been conducted research Limited • with dis individual trees in stands and on root other can co-occur rot root Laminated • eco recover killed to trees and recently declining on be logging conducted Salvage may Other Effects and Associations • • at estimated are in British Columbia rot root laminated losses to volume wood Annual • an additional operational ( adjustment factor purposes, timber supply For • target below stocking not reduce do was applied, treatment removal an inoculum Unless • thinning when laminated commercial avoid disease distribution aggregated, is clearly Unless • on or of rot the spread effect on root laminated any have not appear to does Fertilization Potential Productivity Implications • productivity and harvestable yield can reduce of rot root managed stands by Laminated • If consider disease is high mortality root and widely distributed in sapling stands, from • spe and lower-susceptibility immune retain stands, infected thinning spacing or When • in trees susceptible remove aggregated, clearly is disease the where stand a thinning When Regeneration/Establishment PLANTING • is generally ineffec density, stocking altering through strategy, avoidance inoculum An • species immune when fill-planting or use tolerant in areas levels, stocking improve To Plantation Maintenance Silviculture Considerations (continued) Silviculture Laminated Root Rot – British Columbia’s Coastal Forests Columbia’s British – Root Rot Laminated

JEM — VOLUME 7, NUMBER 3 43 AUTHOR(S) Test Your Knowledge . . .

British Columbia’s coastal forests: Laminated root rot Forest Health Stand Establishment Decision Aid

How well can you recall some of the main messages in the preceding Extension Note? Test your knowledge by answering the following questions. Answers are at the bottom of the page.

1. Crown symptoms in conifers, such as reduced height growth and stress-induced cone crops, can be caused by several damaging agents including laminated root rot. Which of the following signs and symptoms on affected roots are not indicative of laminated root rot? a) Reddish brown stained wood b) Grey-white, tawny, or purplish ectotrophic mycelia c) Creamy white mycelial fans under the bark d) Masses of brown setal hyphae in pitted, decayed wood

2. Before harvest, a formal root disease survey should be conducted in stands affected by laminated root rot if a visual assessment indicates the following occurrence of the disease: a) > 2.5% b) < 5% c) > 5%

ANSWERS

c c 2. 2. 1.

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