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M•rfi . ' '•• , - . := ' - : •,! , • • • - i! 8/ I am offering these general comments%to the neighbors of - Park and the City of Eugene Public Works Department in that they'Ari'be-. helpful in resolving the problem of the "Hazardous Trees,""a Eastern border of the park. The Douglas Fir trees in the area of concern:: South East of the shelter and. East of Heights Blvd. as it progresses in a North/South direction. These trees are a lot older and less vigorous than the Douglas Fir trees south of the Rhododendron Gardens,. These trees are Iodated close to. the top of a North/South ridge and on the East face of this ridge up to the East boundary of Hendrick's Park. The soil series, taken from a Lane County soil map is a Steiwer Loam.. this series is found_ on a 12 to 20 percent slope. The soil depth ranges from 20 to 40 inches arising from a sandstone parent material. The e- ffective rooting depth is also 20to 40 inches. The soil is rather dro- ughty, demons by the presence of Eadrone and other droughty specic.s. The profusion of the existing root systems being partly above the gr- ound indicates the presence of a shallow soil.. Red RinfRot formerly known as Fames Pini is well represented in this stand of trees. The development of the rot is worth noting. The incip- ient and advanced stage of development of this fungus follows the win- ter wood_ leaving the summer wood generally intact.. The summer wood is characterized by a darker color representing the 1inin component. The lignin is much stronger'thantthe cellulose providing more.structual in- teFity to the tree. If the summer wood. is 0.05 inches or wider the sp- read. of the fungus seeths:ttiThe 'confined the winterwood and : does - not spread as easily in a horizonal direotiVii the bole of the "tree. Thus the strucure of the tree . is::;itot.grea.0..y.affectedby this fungus in it 's early advanced stage, he ‘: 6avelood. infected with this fungus due to the higher moiStureaontelit 'af this tissue. Red Brown Butt Rot or Polyporus.Schweinitzii is a cubical. brown rot generally affecting the lower eight feet of the first log of the tree. • More often the first two to four feet of the tree is all that is en- volved. The fruitng body is a flat shelf .like, velvety structure. None were observed in this area.. Sometimes abtiotmal swelling of the bole is an indicator of this fungus infection. However in this case due to the proximity to the ridge line any swelling with no fruiting body observed would seem to be the result of normal buttressing of the tree •bole in response increased wind. velocity. Again the heartwood. is more suscept- able to invasion by this fungus than, the sapwood due to the higher moisture content of the latter. Tree 'failure occurs due to this fungus only with the development of the advanced stageand then only,when that stage affects the root tissue. Yellow Ring Rot/Laminated Root Rot formerly known as Poria _ , endemic to this area. This fungus's advanced. stage weakens .the sup- porting root structure causing the tree to fall.. Assessment .of the,pre- sence of the incipient stage of this fungus can only be,determinedj7 a hand lens examination of the root crown and the bark on the raotS The fruiting body is seldom Se en. ' My physical examination of the trees in this area on the 18th and 19th of August 1997 showed the existance of Re Ring Rot, that being demon- strated the presence of that rot's fruiting body. The stage of fungus infection- incipient or advanced is unknown A educated guess could be made by boring the infected tree with an increment borer, extracting the core, and examining the core with a hand lens to determine the pre-