Forest Path Written Exam 3

Atropellis piniphila sl

Host: Pines (usually lodgepole near us) Large, sunken perennial cankers around branch stubs, blue/black stain in heart+sapwood, resinous, black apothecia on bark

Perennial cankers

Expands slowly over years, host forms callous wood during growing season to try to heal infection=target cankers

Diffuse canker

Necrosis spreads rapidly, no callous wood formed. Mostly perennial, even spreading during growing season.

Fusarium circinatum

Pitch canker on monterey pine and bishop pine. Copious resinousus and sunken cankers developing on wound sites. Cambium and phloem develop red color from soaking with pitch. Branch dieback and flagging

Phomopsis lokoyae

On douglas fir. Long, sunken target cankers centering around branches. Black apothecia and pycnidia. Causes branch dieback, problematic on drought stressed stands

Dermea psuedotsugae

Dermea canker of douglas fir, sometimes grand fir. Sunken, reddish target cankers. Yellowish apothecia appear 1 yr. after branch death. 

Psuedomonas psuedotsugae

Bacterial gall canker on doug fir. Only sign is blackened tumefaction from surface bacteria 

Cytospora abietis sl

Cytospora canker of true firs (sometimes doug fir) Brick red flagging of target cankered branches (commonly found on arceuthobium witches brooms) Asexual spore tendrils are sign. Can be on hardwoods too!

Porodaedalea canciformans

Porodaedaelea canker on abies (esp concolor near us) Deep, large cankers with P. pini like fruiting bodies in/around them. 

Hendersonula cf. toruloidea sl

hendersonula canker of madrone. Sunken black target cankers with red margins.

Fusioccum arbuti sl

Fusicoccum canker of madrone, Diffuse cankers that turn branch black after death, appears like fire damage.

Dibotryon morbosum sl

Black knot of cherry on prunus sp. Gall like hypertrophies that turn black with psuedothecial masses. Cankerous swellings on branches lead to branch mortality. 

Phytopthora ramoroum

Lethal stem disease on most oaks, non-lethal foliar infections on tanoak, rhododendron, bay laurel, madrone, redwood, and many more. Causes red, outer sapwood staining. Can be managed with injections and selective removal of foliar+suceptible hosts

Taphrina occidentalis

Taphrina proliferation of female alder catkins (red, white alder). Severe infections can cause delayed/reduced bud burst

Arceuthobium

Causes major losses in timber industry (most damaging pathogen in western us and mexico) Witches brooms, explosive seed dispersal. Carb, mineral parasite that reduces photosynthetic output of host because of branch decline. Make homes for birds, tree squirrels

Type A infection

Mistletoe shoots remain near infection site. Endophytic system only keeps pace with cambial growth. (most kinds of mistletoe)

Type B infection

Endophytic system grows with branch, shoots appear along apical branch axis from original infection site (A. douglasii, A. americanum)

Cortical strand

longitudinal across inner bark

Sinkers

extend radially into ray tissues of host xylem

Dwarf mistletoe produce _______.

Cytokinins to simulate nutrient translocation to mistletoe body.

Dwarf life cycle

Seeds disperse (sometimes by bird vectors on feet) and stick to branches with viscin in summer/fall, rainy season washes seeds to optimal location and cause them to germinate. Life cycle takes approx six years before reproduing.

Arcauthobium abietinum fsp. concoloris

Flat, compact witches brooms, often with cytospora abietis. Flowering June-Oct, fruiting Aug-Dec

A. abietinum fsp. magnificae

Fat witches brooms, also occurs with cytospora. On abies magnificae and other firs

A. californicum

On sugar pine. Flower June-Sept, fruiting Aug-Nov

A. monticola

On Pinus monticola, occasionally Picea breweriana

A. campylopodum

On Pinus ponderosa, and jeffreyi. Upturned brooms and trunk tumefactions. Flowering July-Nov, fruiting Aug-Dec.

A. siskiyouense

On Pinus attenuata

A. americanum

On Pinus contorta ssp. murrayana (mountain contorta sp.) Flowering Mar-July, fruiting July-Oct.

A. occidentale

On Pinus sabiniana. Lack of brooms

A. tsugense

On mountain and western hemlock

A. douglasii

On Psuedotsuga menziesii. Droopy brooms, type B infection. Tiny, very reduced.

Phoradendron

Water and mineral parasites, endozoochorous dispersal by birds. Establishes primary haustorium, then cortical haustorium, then sinkers. Infection lasts 8-10+ years

Viscum album

“Christmas mistletoe”, Native to Europe, introduced in Sebastopol, CA by Luther Burbank.

Phoradendron leucarpum ssp. tomentosum

Oak mistletoe on Quercus

P. leucarpum ssp. macrophyllum

“Big leaf” mistletoe. On non-Fagaceae hardwoods

P. bolleanum

“Fir-juniper mistletoe”

P. juniperinum

On Calocedrus decurrens, reduced lvs, photosynthetic stem