Table of conifer stem decays. Stem, butt, and root decay fungi of live conifer trees in Alaska with decay type, hosts, and common modes of infection. Includes the conifers: western hemlock (Tsuga heterophylla), mountain hemlock (Tsuga mertensiana), western redcedar (Thuja plicata), shore pine (Pinus contorta ssp. contorta), larch (Larix laricina) and Sitka, Lutz, white, and black spruce (Picea sitchensis, P. lutzii [glauca x sitchensis], P.glauca, P. mariana). Decay Decay Fungi1 Hosts in Alaska Mode of Infection Known Distribution in Alaska Type Genetic work to date has vegetative spread (or all conifers (& detected A. sinapina from SE AK Armillaria spp. white spores) to stressed or hardwoods) to the Kenai Pen. to the Arctic dead trees Circle likely root-to-root Possibly throughout range of Ceriporiopsis white western redcedar contact & subsequent western redcedar and yellow- rivulosa spread into butt cedar in SE AK; specifics unknown spruce, hemlock, larch Coniophora sp. brown (occasionally through wounds hardwoods) mountain hemlock Found in boreal-coastal forests; Echinodontium through branch stubs or brown (occasionally western in coastal forests north of Haines tinctorium live branches hemlock) and Skagway, Mitkof Island spruce, hemlock, pine, Fomitopsis Most common conk on dead and brown larch; sometimes through wounds pinicola down wood in coastal AK redcedar & birch Semi-rare in old-growth coastal Fomitopsis through wounds, brown spruce, hemlock, larch forests of SE AK; specifics officinalis broken tops unknown Ganoderma applanatum more spruce, hemlock (& through wounds, Ganoderma spp. white common; both distributed hardwoods) broken tops throughout SE AK Heterobasidion western hemlock, Sitka white through wounds SE AK annosum spruce spruce, hemlock, shore Laetiporus through wounds, basal Common on lower tree boles of brown pine (some sulphureus scars snags in SE AK hardwoods) white/Lutz spruce Detected NW of Anchorage; work through root-to-root Onnia tomentosa white (occasionally Sitka is underway to better map its contact spruce & shore pine) distribution in SC and Interior AK spruce, pine western Phaeolus through wounds, basal Common in coastal spruce forests brown redcedar, larch, schweinitzii scars & disturbed roots in SE AK occasionally hemlock through bole wounds, Old-growth coastal forests of SE Phellinus hartigii white hemlock branch stubs, or cracks AK; specifics unknown likely through root-to- Possibly throughout range of western redcedar root contact & western redcedar in SE AK Phellinus weirii white (possibly yellow-cedar) subsequent spread into (Kupreanof Island south); butt specifics unknown Widespread in coastal forests; hemlock, spruce, Porodaedalea through branch stubs or detected in boreal-coastal white western redcedar, pini live branches transition forests, less common in shore pine, larch boreal forests 1 Some root rot fungi are included because they are capable of causing both root and butt rot of conifers. .