Forest Health. Forest Health at DNR. Organisms and events that: What does a healthy forest look like? Forest Health Concepts: 9/11/2018

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1 Forest Health Forest Health at DNR Provide technical assistance, monitoring, education, and research. Forest Pathology tree diseases Includes fungi, bacteria, viruses Glenn Kohler, Forest Entomologist Washington Department of Natural Resources Forest Entomology tree insects Includes bark beetles, weevils, defoliating caterpillars, sucking insects (like aphids) Organisms and events that: Kill trees Slow tree growth Damage wood products What does a healthy forest look like? Douglas-fir beetle Ambrosia beetle wood damage Swiss Needle Cast Forest Health Concepts: Forests are defined as healthy if they have sufficient resiliency to respond to and recover from encountered stress while maintaining their capacity to provide necessary ecological process support and generate desired levels of amenities and products. NASF Forest Health Charter. John H. Cashwell. April, Landowner objectives are key 2. Understand forest ecosystem processes Diseases and insects are a natural part of ecosystem; at low levels act as thinning agents recyclers At high levels, they can cause structural changes in the forest 1

2 Stand Development over time Forest Health Concepts: 3. Host species, host condition, and environmental conditions influence ability of pathogen (or insect) to cause damage. Swiss needle cast Douglas-fir is the only host Fungus that blocks stomates Disease Fungus requires a moist climate to reach damaging levels Environment Aerial survey for SNC damage Forest Health Concepts: 4. Low maintenance forests are made up of vigorous trees that are resilient and resistant to pests and damage. Vigorous trees can recover from damage or disease Adventitious root growth Fire scorched ponderosa pine 2

3 Root Diseases Root disease centers are usually localized All sizes of susceptible trees can be affected Often spread by root to root contact Root disease symptoms Thinning crowns Stress-crop of cones Often precedes bark beetle attack July September Root disease symptoms Reduction of shoot growth Root disease symptoms Roots covered with fungal mycelium Chlorotic (yellow) foliage Highly decayed root system 3

4 Laminated Root Rot Armillaria Root Rot Ectotrophic mycelium Most susceptible hosts: Douglas-fir, mountain hemlock, true fir Seldom damaged: Pines Resistant: Hardwoods, western red cedar Broad host range Opportunist: takes advantage of weak trees Annosus Root and Butt Rot Root Disease management Maintain high tree vigor Species manipulation Manage symptomatic trees + 2 tree widths (buffer) Stump removal or push-over logging Treat cut stumps for annosus Do nothing Most susceptible hosts: True firs, hemlock, ponderosa and lodgepole Seldom damaged: White pine, larch, spruce, red cedar Wounds Heart Rot and Butt Rots Prune when branches are small so wounds seal quickly 15 different common types in the Pacific Northwest Decayed trees can be great for wildlife Bark removal allows decay fungi to enter 4

5 Heart Rot and Butt Rots Plan roads carefully Keep vehicles away from leave trees Minimize stand entries Bark Beetles Bark beetles are coming!!! THIS: OR THIS? egg gallery larval galleries Bark Beetles Are generally tree host and size specific Attack trees weakened by competition, defoliation, drought, root disease, and fire Some build populations in storm/fire damage Some species can switch to coordinated mass-attack of vigorous trees Death occurs rapidly Damage may not show up until tree dries out one year later 5

6 Douglas-fir Beetle Dendroctonus pseudotsugae Host: Douglas-fir Breeds in felled, injured or diseased trees, resulting in widely scattered mortality Prefers >10 inch DBH trees Epidemic populations kill apparently healthy trees over extensive areas Commonly group kill Wood Borers Bark Beetles Douglas-fir beetle Signs of attack Boring dust Pitch streams Douglas-fir beetle Pouch fungus Cryptoporus volvatus Green attacked tree pitch streaming (attacks often heaviest 30 ft. up bole) Eggs laid on alternating sides of vertical egg gallery Typical western WA gallery pattern Douglas-fir beetle management Maintain tree vigor Don t injure stems or roots Douglas-fir beetle management Less than 5 large (>8 DBH) dead DF per acre is low risk. Include standing dead DF (crown blown out). Salvage blowdown before two springs pass. Salvage infested trees before next spring. 6

7 Douglas-fir beetle repellent: MCH (antiaggregation pheromone) Best for high value trees yards, campgrounds, old growth Cost ~ $75/ acre Bubble caps must be applied before April flight Other bark beetles in western WA Fir engraver Hosts: true firs (Abies species) Douglas-fir engraver & DF pole beetle Host: Doug-fir Pine bark beetles (mountain pine beetle, Ips species) Hosts: western white pine, shore pine, ponderosa, ornamental pines Spruce beetle Hosts: Sitka spruce and Engelmann spruce Douglas-fir pole beetle gallery Fir engraver gallery General bark beetle management Maintain tree vigor (reduce stress, manage spacing for site) Manage large inputs of fresh dead trees Removal of green attacked trees Pesticides protect and prevent, no use as a cure Foliar diseases: needle casts needle blights rusts Foliage Diseases - Typically not mature tree killers, but often cause growth losses. - Some fungi may also damage stems. - Strongly influenced by local weather. Swiss Needle Cast Native foliar disease Host: Douglas-fir Impacts growth loss 7

8 Tree Defoliating Insects Swiss Needle Cast damage from the air Defoliators of Deciduous Trees tent caterpillars Malacosoma species Hosts alders, poplars, oak, willows, birch, other hardwoods Severity outbreaks short-lived, trees recover but repeated heavy defoliation may cause dieback western tent caterpillar (Malacosoma californicum) Forest tent caterpillar defoliation of red alder, July 2009 Same stand, October 2009 Photos: Mike Johnson, WADNR forest tent caterpillar (Malacosoma disstria) Pacific tent caterpillar (Malacosoma constrictum), prefers oaks) tent caterpillars 2013: 6,100 acres 2012: 8,000 acres Conifer Defoliators western hemlock looper Hosts western hemlock, true firs, Douglas-fir, spruce, numerous shrubs Severity can feed on all age classes of foliage, so heavy defoliation can kill trees in one season. Outbreaks last 2-3 years. Recent outbreaks: 2013 (Pacific tent caterpillar in oak, Klickitat Co., WA) (western tent caterpillar in western WA) 2009 (forest tent caterpillar in northeast WA) 8

9 western blackheaded budworm Hosts western hemlock, spruce, true firs, Douglas-fir Severity primarily feeds on current foliage, but repeated defoliation can cause top-kill and mortality. Outbreaks typically last 2-4 years. Silver spotted tiger moth - Lophocampa argentata Western spruce budworm Other Conifer Defoliators Dwarf mistletoe Hosts: most conifers, but species specific Douglas-fir tussock moth Sawflies Parasitic plants divert host tree s water and nutrients Stunts growth, causes witches brooms, increases fire risk Reproduce by explosive seed rain onto lower hosts (seed can fly ft) Brooms are important animal habitat Dwarf mistletoe management Bigleaf Maple Dieback and Decline Mistletoe responds to light Prune brooms Girdle trees Remove badly infested trees, may also girdle Keeping an infected host in the canopy? Remove trees below that are the same species. Bigleaf maple decline. 9

10 Bigleaf Maple Dieback and Decline Wood Borers Map of sites surveyed for the causes of bigleaf maple dieback and decline (right). Three families of large wood borers Wood borers Most species infest trees that are recently dead or highly stressed. Metallic wood borers Flat-headed wood borers Family Buprestidae Long-horned wood borers Round-headed wood borers Family Cerambycidae Most need fresh phloem to start their life cycle (except ambrosia beetles & wood wasps) Woodwasps Other colorful names Family Siricidae Bark beetle larva Some species take several years to develop into adults Wood borer damage/benefits 10

11 Wood borer frass Sapsucker damage Ambrosia beetles Occupy dead wood in a specific moisture range Rear fungi to eat and feed their larvae Pitch moths Hosts: Pine, spruce, Douglas-fir Symptoms/Signs: Golf ball size globs of pitch Impact: Slows the closure of wounds Can contribute to a line of weakness Ambrosia beetle boring dust Black-stained tunnels in sapwood Adult moths fly in mid-summer Pitch moths Avoid extensive pruning in spring White pine weevil (spruce weevil) Hosts: Sitka spruce, Engelmann spruce, western white pine Weevils need high temperatures and fast growing leaders. Inland grown Sitka spruce most susceptible (warm areas without fog) Causes reduced growth and deformities in wood 11

12 White pine weevil management Plant Sitka spruce on coastal sites Plant non-host trees Dense plantings, delayed thinning (older trees attacked less) Overstory shading Weevil resistant seedlings may be available Introduced (exotic) Insects and Diseases Some introduced by accident or on purpose Native vegetation do not have natural defenses against introduced organisms Can cause wide scale damage and mortality Exotic Insects and Diseases of concern in WA Not established: Sudden oak death Gypsy moth Established in our forests: White pine blister rust Balsam woolly adelgid Larch casebearer citrus long-horned beetle Exotic Wood Boring Beetles not established in WA emerald ash borer Asian long-horned beetle Native species that look like exotic wood borers Golden Buprestid Pine Sawyer Beetles White pine blister rust Banded Alder Borer Hosts: 5-needle pines (western white pine) 12

13 White pine blister rust management options Pruning Planting genetically enhanced seedlings Infected Ribes Sudden Oak Death Cankers on susceptible oaks and tanoak Infects over 20 species in 12 families No obvious signs Can spread through rain splash, soil movement, on boots, paws, hooves, and in streams and rivers Found in 32 WA nurseries Balsam Woolly Adelgid NON-NATIVE Adelges piceae Balsam Woolly Adelgid can be confused with: Hosts: True firs (Abies) Cooley spruce gall adelgid Hemlock woolly adelgid balsam woolly adelgid symptoms Gypsy moth Twig gouting Red stained sapwood, rotholtz Crown defoliation and stunting in Pacific silver fir 13

14 Other Tree Health Issues Animal damage Bear Porcupine Mountain beaver Weather damage Human-caused damage Drought Many species affected, but some more susceptible than others Injury from the top-down and outside-in Needles and softest tissue appear shrunken Damage may be patchy Roots dry but healthy looking Cedar Flagging Western red cedars Usually visible in late summer and fall Fall Yellowing Older needle drop Winter injury All new foliage may not be damaged Patchy flagging Cambium kill; top-kill Frost cracks Winter injury Frost damage Parch blight Red belt Red belt 14

15 Winter injury Recovery Aerial survey maps and data available online Annual report on aerial survey data and other forest health monitoring mm0106gohe /r6/fhp/highlights /ForestHealth Covers at least 150 different types of conifer damage agents in Northwest 15

16 Canadian Forest Service Natural Resources Canada 580 Booth Street, 8th Floor Ottawa, Ontario K1A 0E4 Tel.: (613) Fax: (613) TTY: (613) (Teletype for the hearing-impaired) 16