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Decays of White, Grand, and Red Firs Katy M

Decays of White, Grand, and Red Firs Katy M

Forest Insect & Disease Leaflet 52 Revised April 2010

U.S. Department of Agriculture • Forest Service Decays of White, Grand, and Red Katy M. Mallams1, Kristen L. Chadwick2, and Peter A. Angwin3

White (), grand fir (), and red fir ( and Shasta red fir, and Abies magnifica var. shastensis) are ecologically and economically important in moist forests in many areas of western . White fir is the most widespread of the three species. Two varieties of white fir are recognized: Rocky Mountain white fir (Abies concolor var. concolor) in southeastern through central to Figure 1. Fallen grand fir exposing rust-red northern , and California white stringy rot and hollow caused by Indian paint fir (Abies concolor var. lowiana) in . western and northwestern California, central Oregon, and the Many fungi invade and decompose Sierra . Grand fir inhabits in stems (Figure 1). stream bottoms, valleys, and lower- Some species are restricted to either elevation mountain slopes in the heartwood or sapwood, while some , and northern Idaho species decay both heartwood and and west of the Continental sapwood. True heart-rot fungi infect Divide. Red fir dominates large areas only living and are confined of cool, moist forest above 5000 feet to the heartwood. They do not in the of California. need natural openings or wounds Shasta red fir occurs in similar to penetrate the , but can infect environments in the northwestern through living, undamaged branches Coast Ranges of California and the and stems. True heart-rot fungi are southern Cascade Mountains in not primary colonizers of dead wood, California and Oregon. although some species continue to

Plant Pathologists, USDA Forest Service, Forest Health Protection - Pacific Northwest Region (1Central Point, OR; 2Sandy, OR) and Pacific Southwest Region ( 3Redding, CA) develop in the wood for a short time understory vegetation. Decayed wood after trees die. Many decay fungi added to the forest floor contributes require openings in the bark for to the physical structure, nutrient entry. True firs do not have a primary composition, and moisture-holding resin system, so exposed wood is capacity of the soil. It provides food highly susceptible to fungal infection. and micro-habitats for a myriad of Openings can result from wounds decomposer organisms. caused by fire, weather, animals, humans, or from natural causes such as branch stubs, open knots, dwarf mistletoe cankers, and dead branches. Wounds can also exacerbate dormant infections. Decay fungi that commonly occur only in the base and roots of trees are known as butt rots. Some of these fungi also cause root diseases. Still other fungi primarily decay wood in dead trees or in dead portions of living trees. Some species Figure 2. Bushy-tailed woodrat in a hollow continue to decay logs and in grand fir. service. Some also decay wood and roots on the forest floor and in the soil. Hollows in trees and logs resulting from the action of certain decay fungi Vegetation Dynamics and are critical components of habitat for many wildlife species. , Ecological Role black , American martens, Vaux’s In general, decay is most prevalent swifts, bats, flying , and in older, larger trees, due at least bushy-tailed woodrats are among the in part to accumulation of wounds species using hollow trees for dens, and an increase in the proportion of roosts, nests, and foraging sites (Figure heartwood over time. Decay fungi that 2). Fungi that decay heartwood in become abundant in old forests may living trees are very important in the be important as disturbance agents formation of hollow trees and logs. that initiate and sustain small canopy Such decay is compartmentalized gaps. This is especially true in areas within the cylinder of heartwood where large-scale disturbances such as that was present when the tree was windstorms or fires are infrequent. In wounded. Hollows occur in the these situations, breakage associated advanced stages of decay when the with decay may be one of the main cylinder of heartwood is weakened to means by which large trees are the point that it collapses inside the brought down, creating small gaps. tree. White, grand, and red firs are In these gaps regeneration of shade- important contributors to hollow-tree tolerant tree species can occur, and habitat caused by decay fungi. Hollow shrub and herbaceous vegetation can chambers in large-diameter trees are develop. Structural complexity of the most useful to wildlife. Because it forest is increased by the presence of takes many decades for large trees down wood, tree regeneration, and with advanced decay to develop, 2 large hollow trees are found primarily rot or brown rot. Distinguishing be- in late-successional and old-growth tween white and brown rot can aid in stands. identifying the causal fungus and the effects of decay on wood structure and Impact and Identification use. White rots are caused by fungi that produce enzymes that decay both Fungi cause significant amounts of the cellulose and lignin in wood. The decay in white, grand, and red firs, re- decayed material may form pockets sulting in loss of merchantable timber, and is often pulpy, fibrous, laminated, reduction in wood quality, windthrow, or stringy. It is usually white, tan, and breakage. Decay is generally more or brownish. In advanced stages the extensive in white fir and grand fir than wood may be completely destroyed, in red fir. Trees with decay in recre- leaving a hollow tree or log. Pulp ation areas and other developed sites yields from wood containing white can be extremely dangerous as they are rot are reduced, but pulp quality is not more prone to failure than sound trees. greatly affected. Most of the common Decay fungi play very important roles decay fungi affecting white, grand, in the ecosystem by creating structural and red firs are white rots. Brown rots diversity, returning nutrients to the soil, destroy cellulose and leave the lignin, and providing crucial wildlife habitat. Young, uninjured fir trees are normally resulting in a column filled with a dry, free from decay, but wounded fir trees brown, crumbly mass. The decayed and fir trees over 140 years old often material is fragile and often disinte- have significant decay. grates into small cubes (Figure 3). Wood colonized by brown-rot fungi, Decay can be difficult to identify in the even in the earliest visible stages of early stages. Incipient decay caused by decay, is greatly reduced in strength some fungi may cause color changes and of little use in service. Since the in wood, but other changes are more cellulose fibers are destroyed, wood cryptic. Fruiting bodies (conks) are affected by brown rot has little value usually good indicators of decay, but for pulp. frequently are not present. Conks vary from fleshy mushrooms to woody shelf- like structures. They can be annual or perennial. Some decay fungi continue to produce conks on down trees or stored logs. Table 1 summarizes the physical characteristics of the common decay fungi affecting white, grand, and red firs. Armillaria species and Hetero- basidion occidentale, fungi that cause root disease in true firs as well as butt Figure 3. Advanced brown cubical decay rot, are covered in Forest Insect and caused by velvet-top fungus. Disease Leaflet (FIDL) 78, Armillaria Root Disease, and FIDL 172, Annosus In the absence of fruiting bodies or Root Disease of Western . visible decay in true firs, symptoms Decay fungi also differ according to such as fire scars, wounds, dead the type of rot they cause: either white tops, broken or bayonet tops, dwarf 3 FRUITING BODY Annual conk, small, round, soft, white when young. May be very numerous Dry and tan when older. on tree Perennial conk, leathery to woody, bracket-shaped, Perennial conk, leathery to woody, top dark white and round when young; older, gray to black and bottom creamy with conspicuous red margin Perennial conk, woody, bracket-like, often clustered Perennial conk, woody, or stacked, top rough, brown to black; bottom pink to rose-colored Conspicuous fruiting body, soft, creamy, coral-like soft, creamy, Conspicuous fruiting body, with downward pointing teeth, infrequent, short-lived Annual conk, shelving, overlapping; top bright flame orange; bottom sulfur yellow; fade to chalky white; falls from tree; rarely found on live trees Annual but persistent conk, round with sunken center, Annual but persistent conk, round with sunken center, yellow to reddish-brown short stalk; top velvety, brittle, dark brown when old; bottom when new, green to brown pores Gilled mushroom, appears in fall groups from common base on trees and stumps, short-lived, fleshy, sticky when wet; top and stem yellow; bottom yellow to brownish gills Perennial conk; top dark brown to black; bottom brown, irregular pores, occur in dense clusters sunken cankers Perennial conk; top dark brown to black, bottom concentrically furrowed, scalloped margin; brown, irregular pores Perennial conk, often under tree limbs; top black, rough, cracked; bottom toothed, gray; interior bright brick-red DECAY Initially soft, gray to cream color, later light Initially soft, gray to cream color, brown, cubical, crumbly Crumbly, rough small cubes, light reddish brown Crumbly, Yellow to reddish-brown, soft, irregular cubes, Yellow thin mats of white to rose-colored fungal tissue in cracks Pocket rot, firm wood between. Pits with blunt ends, honeycomb appearance at log ends Medium sized reddish brown cubes, cracks often filled with mats of white fungal tissue Light to dark brown cubes with resinous white fungal tissue in cracks Honey colored with brown streaks, wood separates at annual rings Pocket rot, spindle shaped pockets, firm wood in between Pocket rot, spindle shaped pockets, firm wood in between Rusty red, soft and stringy, separates at annual Rusty red, soft and stringy, rings White White White White White TYPE Brown Brown Brown Brown Brown DECAY FIELD ID Conks on recently dead trees Conks on dead trees, dead portion of live trees, logs, stumps Conks, old broken tops or bayonet Fruiting bodies Conks on wounds in live trees, stumps, snags, downed wood Conks at tree base or on ground near base, swollen butts Mushrooms, hollow stems Conks, sunken cankers sunken Conks, Conks, punk knots, swollen knots Conks, rusty knots, older trees DECAYED PART OF TREE OF PART Sapwood throughout stem Sapwood first, then heartwood Heartwood, broken tops < 6” in diameter, branch stubs Heartwood, lower stem and butt Heartwood, occasionally sapwood, lower stem and butt Heartwood, roots and butt Heartwood, lower to middle stem Heartwood, lower to middle stem Heartwood, throughout stem Heartwood, middle to upper stem Current name Common name (Proposed name) CAUSAL FUNGUS CAUSAL Cryptoporus volvatus Pouch fungus pinicola Red belt fungus Rose-colored conk abietis Coral fungus sulphureus (Laetiporus conifericola) Sulfur fungus or Chicken-of-the- Phaeolus schweinitzii top or Cow-pie fungus Velvet Phellinus cancriformans cancriformans) (Porodaedalea Butterfly conk Pholiota adiposa and limonella cap fungus and lemon Yellow Phellinus pini pini) (Porodaedalea Ring scale fungus Echinodontium tinctorium Indian paint fungus NAME OF ROT NAME OF Gray brown sap rot Gray brown Brown Crumbly Rot Brown Brown top rot Brown Yellow Pitted Rot Yellow Mottled Rot Brown Cubical Rot Brown Schweinitzii Root and Brown Butt Rot, or Cubical Butt Rot Red Ring Rot Canker Red Ring Rot, or Red Ring Rot, or White Speck Rust-Red Stringy Rot Table 1. Characteristics of common decay fungi affecting white, grand, and red firs 1. Characteristics of common decay fungi affecting Table 4 - 3 Deduct 16 ft. for a single conk; Deduct 16 ft. above and below for a group of conks Deduct 8 ft. for a single swollen knot Deduct 8 ft. above and below for a group of swollen knots est conk Single small young conk, deduct 8 ft. above and below conk Lowest conk 0-32 ft from ground, deduct 12 ft. below conk, 21 feet above high Lowest conk > 32 ft. from ground, deduct 20 below lowest conk, 21 above highest conk Conks in bottom ⅓ of tree, cull middle and Conks in top ⅓ of tree, cull and middle 2 or more conks ≥ 25 ft. apart, cull entire tree Conks – – Swollen knots – – None Western Oregon Western Oregon: White and red fir in SW • • • • • • age > 125 years: Tree • • Oregon, deduct 4 ft. below the bottom of lowest canker White and red fir in SW or conk, and 6 ft. above the top of highest None Oregon, deduct 1 ft. below the bottom and 2 above White and red fir in SW top of a wound Oregon, deduct 1 ft. below the bottom and 2 above White and grand fir in SW top of a wound None None None 2 4 < 19”, deduct 18 ft. above and 13 below 19.0-26.9”, deduct 20 ft. above and 18 below 27.0-34.9”, deduct 20 ft. above and 21 below ≥ 35.0” , deduct 20 ft. above and 22 below < 200 years, deduct 8 ft. above and below ≥ 200 years, deduct 16 ft. above and below Conk on ground or at base, deduct 8 ft. above; deduct 2 ft. above top of scar or 8 Conk and basal scar, ft. of butt, whichever is greater Conk, deduct 4 ft. below and above; or 4 deduct 2 ft. above and below scar, Conk and scar, ft. above and below conk, whichever greater Conk, deduct 4 ft. below and above; or 4 deduct 2 ft. above and below scar, Conk and scar, ft. above and below conk, whichever is greater Tree dbh: Tree age: Tree Cull from ground to 8 ft. above highest conk Pacific Northwest • • • • • • Same as Red Ring Rot • • • • • • Cull from top of tree down to 16 ft. below lowest conk Deduct 6 ft. above and 4 below each conk Old conks, 1 to 4 inch diameter reduction scaling cylinder Forest Service, PNW-GTR-144. Portland, OR. 17 p. Forest Service, PNW-GTR-144. and : 1 in bottom ⅓ of tree, cull lower ⅔ tree in middle ⅓ of tree, deduct 20 ft. below lowest to 21 above highest conk in top ⅓ of tree: cull upper ⅔ tree Deduct 8 ft. above and below each conk Deduct 4 ft. above and below each swollen knot Deduct 16 ft. above and below each conk Deduct 8 ft. above highest to below lowest swollen knot – – – – – – – Single small conk on young tree, deduct 8 ft. above and below Lowest conk 0-32 ft from ground, deduct 12 below lowest to 21 above highest conk Lowest conk > 32 ft. from ground 2 or more conks ≥ 25 ft. apart, cull entire tree age < 150 (or 24” dbh) Tree age ≥ 150 years (or 24” dbh) Tree Conk on bole of tree, cull butt log Conk on ground or roots, deduct 8 feet of butt log One conk indicates total cull deduct 4-6 ft. above top of scar Decay visible in basal scar, None • • • • • • • • • • California None Same as Red Ring Rot Deduct 8 feet above and below each conk or group of conks None None ) ) ) ) ) ) ) ) Yellow Pitted Rot Yellow ( Hericium abietis NAME OF ROT (Causal fungus) ROT NAME OF Rust Red Stringy Rot ( Echinodontium tinctorium Mottled Rot ( Pholiota adiposa and limonella Red Ring Rot Canker ( Phellinus cancriformans Red Ring Rot, or White Speck Red Ring Rot, or ( Phellinus pini Schweinitzii Root and Butt Rot, or Cubical Butt Rot Brown ( Phaeolus schweinitzii Cubical Rot Brown ) ( top rot Brown ( Fomitopsis cajanderi Crumbly Rot Brown ( Gray brown sap rot Gray brown ( Cryptoporus volvatus ) USDA Forest Service. 2005. Chapter 20- Estimating Tree Volume and Weight. Timber Cruising Handbook. R5 FSH Supp. 2409.12-2005-2. 25 p. Timber Weight. and Volume Tree Forest Service. 2005. Chapter 20- Estimating USDA V. 2 p. Table Timber Cruising Handbook. R6 FSH Supp. 1 5/86 Guide to Estimating Decay in the Pacific Northwest. A Forest Service. 1986. USDA Aho, Paul E. 1982. Indicators of cull in western Oregon conifers. USDA Forest Service R6-NR-FID-PR-01-06, Pacific Northwest Region, Conifers. USDA 2006. Field Guide to Common Diseases and Insect Pests of Oregon Willhite. Goheen, E.M and E.A. Portland, OR. 327 p. Table 2. Guidelines for estimating decay (cull) in white, grand, and red firs Table 1 2 3 4 5 mistletoe stem swellings, or cavities gray and toothed (Figure 4). Interiors excavated by are good indicators are a characteristic orange-red color. that internal decay is present. Frost Advanced decay is reddish-yellow to cracks by themselves do not indicate brown, and fibrous or stringy. This internal decay, but should be examined fungus often causes separation between closely for additional indicators. It is springwood and latewood resulting in a also common for trees with no visible laminated decay. indicators to have substantial amounts of internal decay. Table 2 summarizes guidelines developed for California, the Pacific Northwest, and western Oregon to estimate the extent of decay in white, grand, and red firs caused by common decay fungi. Estimates for other regions should be based on local surveys as the extent of decay varies from one region to another.

Rust-red Stringy Rot Figure 4. Conk of Indian paint fungus showing the cracked, black top and gray, toothed Rust-red stringy rot, a white rot caused underside. by the Indian paint fungus (Echinodon- Red Ring Rot tium tinctorium), is a true heart rot that accounts for a major portion of the Red ring rot, a white rot caused by stem decay in mature grand and white the ring-scale fungus (Phellinus pini), firs in eastern Oregon and Washington, is another true heart rot that is wide- northern Idaho, and western Montana. spread in western North America. It It is rare in grand firs west of the Cas- causes substantial decay in many co- cade crest. It is responsible for most nifer species, including true firs. Red of the heart rot of white firs in ring rot can be found throughout the and and is also common tree stem, but is most common in the in white firs in southern Colorado. In middle to upper portion. The fungus is California, Indian paint fungus is less thought to infect trees through live and common on red and white firs than the dead branches and branch stubs, but yellow cap fungus, but is still respon- may also gain entry through wounds. sible for substantial decay. Decay Conks are brownish-black and rough caused by Indian paint fungus is most on top. Undersides are cinnamon- common in the middle to upper stem. brown or gold with irregularly shaped The fungus infects small (less than two pores (Figure 5). Conks are often millimeter diameter) dead branchlet formed at old branch stubs and occa- stubs just before they are overgrown by sionally on branches. Swollen knots the branch. The fungus then becomes filled with fungal tissue called “punk dormant until the tree is wounded near knots” are also common. Advanced the infection. Conks of Indian paint decay results in small, spindle-shaped fungus are perennial, large, hoof- pockets filled with white fibers with shaped, and woody. Tops are typically firm wood in between. The closely black and cracked, and undersides are related red ring rot canker fungus 6 remaining, hence red ring rot canker is much more commonly associated with stem breakage than red ring rot.

Schweinitzii Root and Butt Rot Schweinitzii root and butt rot is caused by the velvet-top fungus (Phaeolus schweinitzii). This fungus is wide- spread in conifer forests. It decays heartwood, causing a brown rot in Figure 5. Conk of the ring-scale fungus showing the brownish-black, roughened top the roots and butts of older conifers and cinnamon-brown underside. including white, grand, and red firs, and often results in breakage near the (Phellinus cancriformans) is found base. Fine roots are infected by spores primarily in southern Oregon and that percolate into the soil. Fire scars . It affects all true and other basal wounds probably ex- firs including white, grand, and red acerbate decay in previously infected firs. Red ring rot canker is generally roots and butts. This fungus produces found in the lower stem and sometimes large annual conks, usually on the in mid-stem. Conks, known as but- ground near the bases of infected trees terfly conks, are similar in texture and and occasionally on their stems. The color to ring-scale fungus conks, but upper surface is velvety in texture are smaller and produced in clusters in and red-brown or yellowish when sunken areas on the stem (Figure 6). first produced in autumn. Although These sunken areas, or cankers, are the produced annually, the old dead conks result of the fungus invading and kill- can persist for years. As they age ing cambium in a limited area of the they become dark brown and brittle, stem. The underlying decay is similar earning the name “cow-pie fungus”. to that caused by ring-scale fungus; Advanced decay is reddish-brown and however, there is less sound wood cubical with white fungal material in the cracks.

Mottled Rot

Mottled rot, caused by both the yel- low cap fungus (Pholiota adiposa) and the lemon cap fungus (Pholiota limonella), is a major source of white rot in older grand, white, and red firs in eastern and southern Oregon and in California. Both yellow cap and lemon cap fungi are believed to gain entry to the heartwood through fire scars and other wounds. The resulting decay is Figure 6. Clusters of butterfly conks in a primarily in the middle and lower stem. sunken canker on a white fir stem. Both species produce annual clusters 7 Figure 7. A cluster of fleshy, yellow, gilled mushrooms of the yellow cap fungus. of yellow mushrooms with yellowish- brown gills that last only a few weeks, usually after autumn rain (Figure 7). Advanced decay is brown and mottled. It is often associated with wounds, scars, frost cracks, and dwarf mistletoe Figure 8. Large clusters of fresh conks of the cankers. sulfur fungus associated with old wounds on a red fir snag.

Brown Cubical Rot Yellow Pitted Rot Brown cubical rot, caused by the Yellow pitted rot is caused by the sulfur fungus (Laetiporus sulphureus), coral fungus, Hericium abietis. It is is a common brown rot in conifers and an important decay organism in living hardwoods throughout North America. and dead trees, down wood, and logs In western forests it is most common in the mountains of Oregon, Wash- in true firs, especially red firs. This ington, and northern California. The fungus also gains entry to the heart- fungus invades the heartwood through wood through fire scars and other basal wounds, causing a white rot. There is and stem wounds. Decay is usually also some evidence that it may infect limited to the butt and lower stem. through branchlet stubs, similar to Conks appear in late summer or fall the Indian paint fungus. The decay and are very conspicuous. They are is found in the butt and lower stem of annual, clustered, shelf-like, soft, and live trees, and also in stumps, snags, fleshy. Tops are bright orange when and down wood. Fruiting bodies fresh (Figure 8). Undersides are sulfur of the coral fungus are produced in yellow. As they age they become autumn, but only infrequently. Their brittle and chalky white. They usually presence indicates extensive decay. appear on stumps, snags, old wounds, The fruiting bodies are large, soft, or at the bases of live trees. Advanced white to buff-colored, and coral-like decay is reddish-brown and cubical with downward-pointing spines or with cracks that are often filled with teeth. Advanced decay results in long white fungal material. spindle-shaped pockets separated by firm wood (Figure 9). At the ends of

8 logs it may resemble honeycombs. Brown Crumbly Rot Decay will continue to develop in stored logs. Brown crumbly rot, caused by the red belt fungus (Fomitopsis pinicola), is one of the most common brown rots in western conifer forests. It is abundant in white, grand, and red firs. It most commonly infects and decays dead and down trees, but occasionally causes decay in dead portions of live trees such as those with wounds, broken tops, strip-kill by bark beetles, or stem swellings caused by dwarf mistletoe Figure 9. Advanced decay caused by the coral infection. Conks are perennial, woody, fungus showing the long, spindle-shaped and shelf-like or hoof-shaped. The pockets, or pits, with firm wood in between. top is smooth, and gray or black with a wide red margin (Figure 10). The Brown Top Rot underside is white or yellowish. Brown top rot, caused by the fungus Decay develops first in sapwood Fomitopsis cajanderi, is a widespread and then progresses into heartwood. brown rot in conifer forests in western Advanced decay is brown and cubical. North America. Grand firs are more commonly infected than white firs or red firs, although the fungus and its associated decay are occasionally found in white firs in Arizona and New Mexico, and red firs in California. The fungus primarily infects through wounds caused by broken tops that are less than six inches in diameter, and through branch stubs. Decay develops rapidly, forming soft, irregular yel- Figure 10. Conk of the red belt fungus showing the smooth black top with its wide red margin. low to reddish-brown cubes. Conks The white pore layer underneath is visible are perennial, woody, and shelf-like along the edge. or hoof-shaped. They are brown or black, rough on top, and rose-colored Gray-brown Sap Rot underneath, often appearing in clus- ters. Decay may continue to develop Gray-brown sap rot is caused by the in piled logs and wood in service. The pouch fungus (Cryptoporus volva- impact of this fungus is most notice- tus). It is a very common brown rot able on sites where storms cause in recently dead conifers throughout frequent broken tops. western North America, especially those that are insect-infested or fire- killed. Spores of the fungus are intro- duced into trees by bark beetles and wood borers, making the presence of pouch fungus conks a good indication

9 that trees were infested by bark beetles In situations where the management or wood borers. Conks develop on objective is to minimize losses due tree stems, often in large numbers. to decay, stem-decay fungi must be Conks usually appear within 12 to 18 prevented from infecting young trees. months after the death of a tree. They The most effective preventive action are small, soft, round, and white when is to minimize partial cutting in stands fresh, becoming dry and tan with age. with a substantial component of white, Decay develops rapidly, but is nor- grand, or red firs. If intermediate stand mally limited to the outer one-half to treatments are conducted, it is impor- two inches of sapwood. Initially the tant to avoid injuring residual trees. decayed wood becomes soft, and gray Basal wounds are the most likely to or cream-colored. In more advanced become infected and are therefore the stages it is light brown, cubical, and most critical to prevent. During thin- crumbly. The pouch fungus plays ning and other harvest activities the an important role in beginning the following actions can prevent wound- process of recycling dead wood and ing and associated decay in residual contributes to the rapid failure of many trees: beetle-killed trees. It may affect mer- • Avoid operations during spring and chantable volume of salvage logs if early summer when tree bark is eas- harvest is delayed, especially in small ily damaged. trees. • Use appropriate size and type of equipment for site and stand condi- Management tions. • Mark leave trees rather than cut Management objectives will determine trees. This has been shown to the amount of decay that is acceptable significantly decrease damage to in a given stand. As old-growth stands residual trees. have been harvested and replaced • Designate skid trails and skyline with more uniform, managed, young- corridors in advance. Avoid sharp growth stands, the overall amount of turns and leave bump trees or cull stem decay has decreased. In stands logs to protect residual trees adja- where management objectives include cent to trails. enhancing ecological function and • Leave low stumps in skid trails providing wildlife habitat, strategies (preferably no more than three to promote infection by stem-decay inches high). fungi and development of decay may • Use directional felling to reduce the be needed. These strategies include amount of skidder maneuvering and retaining existing wounded and hollow log pivoting. trees, promoting the replacement of • Limb and top trees prior to skid- hollow trees by maintaining advanced ding. true-fir regeneration with indicators of • Design contract specifications to infection, and intentionally wounding ensure the intended results. selected true firs to encourage infec- • Avoid underburning in true fir tion by stem-decay fungi. stands unless slash, debris, and duff within ten feet of residual trees can be removed beforehand.

10 Decay caused by Indian paint fungus some cases, creative treatments such as is a major factor almost everywhere topping, leaving high stumps, or fall- advanced regeneration of true firs is ing without removing tree stems may managed. The amount of decay due mitigate the hazard while maintaining to this fungus can be minimized by wildlife habitat. Along roads and in avoiding management of suppressed work areas, trees with indicators of regeneration that has developed under- decay should be assessed and treated neath infected overstories. FIDL 93, depending on the frequency and dura- Rust-Red Stringy Rot caused by the In- tion of human exposure. Favoring dian Paint Fungus, contains guidelines a mix of decay-resistant tree species for assessing advance regeneration for such as pines, , incense-cedar, and infection potential and decay caused Douglas-fir over true firs can reduce by Indian paint fungus. Advanced problems associated with decays and regeneration of true firs is at risk of is highly recommended in vegetation developing severe decay when it has management plans for developed sites. been suppressed for over fifty years, has numerous wounds, is low in vigor due to poor site, or when an infested Selected References overstory of true firs is present. If Aho, P.E., G.M. Filip, and F.F. Lombard. three or more of these conditions exist 1987. Decay and wounding in advance and significant levels of decay in the grand and white fir regeneration. Forest mature stand would hinder long-term Science 33(2): 347-355. management objectives, other tree Bull, E.L., C.G. Parks, and T.R. Torgersen. species should be favored or planted. 1997. Trees and logs important to wildlife Stands at risk of developing severe in the Interior Basin. decay can also be managed on short USDA Forest Service, General Technical rotations so maximum merchantable Report PNW-GTR-391, Portland, OR. 55p. volume is harvested before decay Burns, R.M. and B.H. Honkala. 1990. becomes significant. Silvics of North America: Volume 1, Conifers. USDA Forest Service, A significant number of tree failures in Agriculture Handbook 654, Washington, recreation areas and other developed D.C. 675p. sites are caused by the effects of decay Filip, G.M. and C.L. Schmitt. 1990. Rx for fungi. Trees within falling distance of Abies: Silvicultural options for diseased valuable targets should be examined firs in Oregon and Washington. USDA periodically for external indicators of Forest Service, General Technical Report decay. Sometimes external indicators PNW-GTR-252, Portland, OR. 34p. are not visible or are not sufficient to determine the degree of decay. Ques- Filip, G.M., D.J. Goheen, and J.W. Kinney. 2009. Rust-red stringy rot caused by the tionable trees can be bored with a drill, Indian paint fungus. USDA Forest Service, increment borer, or resistograph tool Forest Insect and Disease Leaflet 93, to assess their structural integrity by Portland, OR. 11p. determining the thickness of remaining sound wood. If decay is found, prob- Goheen, E.M. and E.A. Willhite. 2006. Field guide to the common diseases and ability of failure and potential targets insect pests of Oregon and Washington will dictate the appropriate treatment conifers. USDA Forest Service, R6-NR- to reduce or eliminate the hazard. In 11 FID-01-06, Pacific Northwest Region, Portland, OR. 327 p. Assistance Private landowners can get more Hagle, S.K., K.E. Gibson and S. Tunnock. information from County Extension 2003. Field guide to diseases and insect Agents, State Forestry Departments, or pests of northern and central Rocky State Agriculture Departments. Federal Mountain conifers. USDA Forest Service, resource managers should contact USFS R1-03-08, Northern and Intermountain Forest Health Protection (www.fs.fed.us/ Regions, Missoula, MT. 197p. foresthealth/). This publication and other Forest Insect and Disease Leaflets can be Harvey, R.D., Jr. and P.F. Hessburg, Sr. found at www.fs.fed.us/r6/nr/fid/wo-fidls/. 1992. Long-range planning for developed sites in the Pacific Northwest: the context of hazard tree management. USDA Forest Service, FPM-TP039-92, Pacific Northwest Acknowledgments Region, Portland, OR. 120p. This is a revision of Forest Pest Leaflet 52, Heart Rots of Red and White Firs, Hunt, R.S. and D.E. Etheridge. 1995. True written by J.W. Kinney and H.H. Bynum, heart-rots of the Pacific region. Forest Pest Jr. in 1961. Reviews were provided by Leaflet No. 55, Natural Resources / Marcus Jackson, Jim Worrall, Mary Lou Canadian Forest Service, Victoria, British Fairweather, Jim Hoffman, Don Goheen, Columbia. 8 p. and Greg Filip (USDA Forest Service Forest Health Protection in Missoula Scharpf, R.F. 1993. Diseases of Pacific MT, Gunnison CO, Flagstaff AZ, Boise coast conifers. USDA Forest Service, ID, Central Point, and Portland OR), and Agriculture Handbook 521, Washington, by Brennan Ferguson (Ferguson Forest D.C. 199p. Pathology Consulting, Inc. Missoula MT). Jessie Glaeser (Northern Research Station, Schmitt, C.L., J.R. Parmeter, and J.T. Madison WI) provided current taxonomic Kliejunas. 2000. Annosus root disease information. of western conifers. Forest Insect and Disease Leaflet 172. USDA Forest Service, Photos: Washington, D.C. 9p. USFS: Evelyn Bull (Figures 1& 2), Ellen Goheen (Figures 3, 5, & 6), Don- Williams, R.E., C.G. Shaw, III, P.M. ald Goheen (Figure 4), James Hadfield Wargo, and W.H. Sites. 1986. Armillaria (Figure 7), Martin MacKenzie (Figure root disease. Forest Insect and Disease 8), Gregory Filip (Figure 9). Leaflet 78. USDA Forest Service, OR Dept. Forestry: Alan Kanaskie Washington, D.C. 8p. (Figure 10).

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic informa- tion, political beliefs, reprisal, or because all or part of an individual’s income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410, or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer.

Published by USDA Forest Service, Pacific Northwest Region (R6), Portland, Oregon FS/R6/RO/FIDL#52-10/003 12 Pesticide-Information Disclaimer

This page is not part of the original publication.

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This USDA Forest Service Forest Insect & Disease Leaflet (FIDL) contains useful and pertinent information on forest insect and (or) disease biology, identification, life cycles, hosts, distribution, and potential management options.

Some FIDLs, however, discuss and (or) recommend pesticides that are no longer registered with the U.S. Environmental Protection Agency or are no longer available for use by the general public. Use of these pesticides is neither recommended nor endorsed by the Montana DNRC.

Before using any pesticide be sure to consult either a forest health specialist; state extension agent; your state’s Department of Agriculture, Natural Resources, or Forestry; or other qualified professionals or agencies; with any questions on current pesticide recommendations for forest insects and diseases.

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