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• 3891. [Article] Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1989

  Evaluations of previously established field trials indicate that chioropicrin, and Vorlex continue to provide protection to Douglas-fir poles, although the degree of protection is diminishing. Reapplication ...

  Citation × Citation Citation Abstract Copy Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1989 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) Evaluations of previously established field trials indicate that chioropicrin, and Vorlex continue to provide protection to Douglas-fir poles, although the degree of protection is diminishing. Reapplication of Vapam 18 years after the initial application eliminated fungi which had recolonized the poles. Methylisothiocyanate (MITC) continues to protect Douglas-fir poles 12 years after application. Gelatin encapsulation of MITC or chioropicrin appears to have no negative influence on fungitoxicity of these chemicals. Application of water to decompose the gelatin accelerated initial chemical release, but had no longterm effects on performance. A series of laboratory trials have been established to evaluate the performance of sodium n-methyldithiocarbamate (NaMDC), the active ingredient of Vapam. This chemical decomposes more slowly than the liquid formulations and a number of additives are being evaluated to accelerated decomposition. Along with the solid NaMDC, a pelletized formulation of Vapam was evaluated which contained 15 or 40 % NaMDC. These evaluations indicated that the addition of water accelerates release, but the fungal survival in these tests was more variable. The results suggest that a dosage 2 times greater than the liquid formulation is required for effective fungal control; however, further tests are planned to confirm these results. The evaluations of MITC-FUME in Douglas-fir and southern pine poles indicated that MITC has moved to a greater extent in Douglas-fir. Both closed tube bioassays and gas chromatographic analyses of ethyl acetate extracts of wood samples indicated that MITC was present at higher levels in Douglas-fir poles. Southern pine is far more permeable than Douglas-fir and MITC movement should be more rapid in this species. Further tests are planned to identify the nature of this delayed movement. 11 Evaluations of Dazomet, a crystalline solid which decomposes tO produce MITC in wood, indicate that detectable levels of this chemical are present in virtually all of the treatment groups. The decomposition rate of this chemical is normally too slow for effective fungal control and these trials are examining the ability of various additives to accelerate decomposition. Further evaluations of pole sections treated with Dazomet and selected additives are underway. A study to evaluate the effect of voids on fumigant effectivness suggests that voids do not adversely affect MITC movement through Douglas-fir pole sections. These results indicate that treatment of voids should be costeffective if the chemical is not applied directly to the void and if the pole retains a sufficient degree of strength. We continue to develop and refine a model for simulating the movement of MITC through Douglas-fir under varying temperature and moisture conditions. The model has been improved to permit three dimensional evaluations, but the times required for computation are still somewhat long. Further evaluations using a variety of environmental conditions are planned. Evaluations of potential replacements for pentachiorophenol for treatment of western redcedar sapwood and field drilled bolt holes have identified several promising alternatives. These chemicals are now under study in several modified field and laboratory tests. Field trials of several potential treatments for field drilled bolt holes indicate that Boracol 40, disodium octaborate tetrahydrate and ammonium bifluoride provided excellent protection over an 8 year period. These formulations all are relatively safe and can be easily applied in the field. 111 A laboratory trial to evaluate the effects of selected basidiomycetes on strength of Douglas-fir sapwood and heartwood has concluded. Fungal density, measured as the average number of fungi colonies per beam, gradually increased in all of the beams while longitudinal compression strength (LCS), modulus of rupture (MOR), and modulus of elesticity (MOE) slowly declined. Of the measurements, LCS appeared to be most useful, probably owing to the increased number of sampling sites per beam. The results indicate that the degree of colonization was not a good indicator of wood strength effects. The value of kerfing for decreasing post-treatment checking and improving the service life of Douglas-fir poles was evaluated using a series of inspection reports from a local utility. Kerfed transmission poles had substantially lower rates of internal decay and rejection, but there appeared to be little difference in the rate of decay between kerfed and non-kerfed distribution poles. The evaluation of disodium octaborate tetrahydrate for preventing colonization of air-seasoning Douglas-fir pole sections has been completed. Spraying with a 10 % boric acid equivalent solution (BAE) at 6 month intervals provided the greatest degree of protection, although dipping in a 20 % BAE solution at the start of air-seasoning produced a similar degree of protection. As expected, fungal colonization was far lower at the dryer Oroville site and borate treatment had little influence on the degree of fungal colonization at this site. The results indicate that borate treatment at the start of airseasoning is a viable method for limiting fungal colonization in moist airseasoning sites west of the Cascade Mountains. Evaluations of the tolerance of Stereum sanguinolentum and Peniophora spp. to elevated temperature exposures indicated that both of these fungi were extremely sensitive to elevated temperatures. The lack of long-term survival structures in these fungi probably accounts for this susceptibility to heat. iv A series of trials which measured internal temperatures in Douglas-fir pole sections during treatment with ammoniacal copper arsenate were used to develop a model for predicting internal heating during steaming. The results indicated that previous heating curves were overly optimistic in their prediction of heating. A series of heating curves for various pole diameters and starting conditions are presented. A number of externally applied groundline treatments are under evaluation in a field trial at Peavy Arboretum and a second trial will be established in the San Francisco Bay area. Seven formulations (including standards) are included. The Peavy site will be sampled in the next few months. The performance of copper naphthenate in western wood species is being evaluated in a series of small western redcedar sapwood stakelets which have been treated to a range of retentions and exposed in the fungus cellar. The results will be used to help confirm the performance of copper naphthenate in this species. Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1989 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) Evaluations of previously established field trials indicate that chioropicrin, and Vorlex continue to provide protection to Douglas-fir poles, although the degree of protection is diminishing. Reapplication of Vapam 18 years after the initial application eliminated fungi which had recolonized the poles. Methylisothiocyanate (MITC) continues to protect Douglas-fir poles 12 years after application. Gelatin encapsulation of MITC or chioropicrin appears to have no negative influence on fungitoxicity of these chemicals. Application of water to decompose the gelatin accelerated initial chemical release, but had no longterm effects on performance. A series of laboratory trials have been established to evaluate the performance of sodium n-methyldithiocarbamate (NaMDC), the active ingredient of Vapam. This chemical decomposes more slowly than the liquid formulations and a number of additives are being evaluated to accelerated decomposition. Along with the solid NaMDC, a pelletized formulation of Vapam was evaluated which contained 15 or 40 % NaMDC. These evaluations indicated that the addition of water accelerates release, but the fungal survival in these tests was more variable. The results suggest that a dosage 2 times greater than the liquid formulation is required for effective fungal control; however, further tests are planned to confirm these results. The evaluations of MITC-FUME in Douglas-fir and southern pine poles indicated that MITC has moved to a greater extent in Douglas-fir. Both closed tube bioassays and gas chromatographic analyses of ethyl acetate extracts of wood samples indicated that MITC was present at higher levels in Douglas-fir poles. Southern pine is far more permeable than Douglas-fir and MITC movement should be more rapid in this species. Further tests are planned to identify the nature of this delayed movement. 11 Evaluations of Dazomet, a crystalline solid which decomposes tO produce MITC in wood, indicate that detectable levels of this chemical are present in virtually all of the treatment groups. The decomposition rate of this chemical is normally too slow for effective fungal control and these trials are examining the ability of various additives to accelerate decomposition. Further evaluations of pole sections treated with Dazomet and selected additives are underway. A study to evaluate the effect of voids on fumigant effectivness suggests that voids do not adversely affect MITC movement through Douglas-fir pole sections. These results indicate that treatment of voids should be costeffective if the chemical is not applied directly to the void and if the pole retains a sufficient degree of strength. We continue to develop and refine a model for simulating the movement of MITC through Douglas-fir under varying temperature and moisture conditions. The model has been improved to permit three dimensional evaluations, but the times required for computation are still somewhat long. Further evaluations using a variety of environmental conditions are planned. Evaluations of potential replacements for pentachiorophenol for treatment of western redcedar sapwood and field drilled bolt holes have identified several promising alternatives. These chemicals are now under study in several modified field and laboratory tests. Field trials of several potential treatments for field drilled bolt holes indicate that Boracol 40, disodium octaborate tetrahydrate and ammonium bifluoride provided excellent protection over an 8 year period. These formulations all are relatively safe and can be easily applied in the field. 111 A laboratory trial to evaluate the effects of selected basidiomycetes on strength of Douglas-fir sapwood and heartwood has concluded. Fungal density, measured as the average number of fungi colonies per beam, gradually increased in all of the beams while longitudinal compression strength (LCS), modulus of rupture (MOR), and modulus of elesticity (MOE) slowly declined. Of the measurements, LCS appeared to be most useful, probably owing to the increased number of sampling sites per beam. The results indicate that the degree of colonization was not a good indicator of wood strength effects. The value of kerfing for decreasing post-treatment checking and improving the service life of Douglas-fir poles was evaluated using a series of inspection reports from a local utility. Kerfed transmission poles had substantially lower rates of internal decay and rejection, but there appeared to be little difference in the rate of decay between kerfed and non-kerfed distribution poles. The evaluation of disodium octaborate tetrahydrate for preventing colonization of air-seasoning Douglas-fir pole sections has been completed. Spraying with a 10 % boric acid equivalent solution (BAE) at 6 month intervals provided the greatest degree of protection, although dipping in a 20 % BAE solution at the start of air-seasoning produced a similar degree of protection. As expected, fungal colonization was far lower at the dryer Oroville site and borate treatment had little influence on the degree of fungal colonization at this site. The results indicate that borate treatment at the start of airseasoning is a viable method for limiting fungal colonization in moist airseasoning sites west of the Cascade Mountains. Evaluations of the tolerance of Stereum sanguinolentum and Peniophora spp. to elevated temperature exposures indicated that both of these fungi were extremely sensitive to elevated temperatures. The lack of long-term survival structures in these fungi probably accounts for this susceptibility to heat. iv A series of trials which measured internal temperatures in Douglas-fir pole sections during treatment with ammoniacal copper arsenate were used to develop a model for predicting internal heating during steaming. The results indicated that previous heating curves were overly optimistic in their prediction of heating. A series of heating curves for various pole diameters and starting conditions are presented. A number of externally applied groundline treatments are under evaluation in a field trial at Peavy Arboretum and a second trial will be established in the San Francisco Bay area. Seven formulations (including standards) are included. The Peavy site will be sampled in the next few months. The performance of copper naphthenate in western wood species is being evaluated in a series of small western redcedar sapwood stakelets which have been treated to a range of retentions and exposed in the fungus cellar. The results will be used to help confirm the performance of copper naphthenate in this species. Close

• 3892. [Article] Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1993

  Evaluation of previously established field trials of internal remedial treatments continues to verify the excellent long-term protection afforded by these treatments. Field trials with gell encapsulated methylisothiocyanate ...

  Citation × Citation Citation Abstract Copy Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1993 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) Evaluation of previously established field trials of internal remedial treatments continues to verify the excellent long-term protection afforded by these treatments. Field trials with gell encapsulated methylisothiocyanate (MITC) demonstrate that gelatin does not interfere with chemical release, nor is addition of supplemental moisture required for release. Field trials have been established to evaluate several new formulations including Basamid plus copper, boron/fluoride rods, and boron rods. Field trials of gelled and pelletized metham sodium indicate that both formulations are moving well through Douglas-fir poles one year after treatment. Evaluations of a copper naphthenate/boron paste for internal treatment indicate that the formulation has moved a short distance from the point of application 3 years after treatment. Boron rod field trials were not fully sampled for residual chemical level this past year; however, evaluation of cores removed from fused borate rod trials in New York indicate that some additional boron diffusion has occurred. Examination of treatment holes suggests that considerable amounts of the boron remain in rod form 2 years after application. In laboratory studies, we have evaluated the use of metham sodium/basamid mixtures and have found that these formulations provide enhanced MITC production over longer periods than either of the components alone. Both formulations were solid, creating the potential for development of safer formulations which provide a rapid release with long term protection. Field trials of these systems will be established in the coming months. Studies also continue with Basamid in an effort to enhance decomposition of this compound. Studies have shown that moisture addition has the most significant effect on decomposition followed by the presence of copper and increasing pH. Further studies on decomposition products are planned to better understand the activity of this molecule. Examination of Douglas-fir timbers treated with metham sodium indicate that MITC levels are similar to those found in poles at similar times after treatment. The presence increased surface area on timbers apparently did not adversely affect diffusion or chemical loss. Evaluation of the fungitoxicity of mixtures of MITC and carbon disulfide is underway in an effort better understand the activity of metham sodium. This compound decomposes to produce a wide array of volatile compounds with varying degrees of toxicity to fungi. Preliminary trials have shown the relatively low toxicity associated with carbon disulfide, a major decomposition product, particularly under acidic conditions. Trials with mixtures will begin shortly. Efforts to develop a three dimensional model of MITC movement are continuing. The model has been evaluated on data collected from small blocks and efforts are underway to verify these results. In addition, full pole grids have been prepared to evaluate the effects of treatment hole geometry and orientation on fumigant movement. Studies to identify alternative treatments for protecting western redcedar sapwood from decay are continuing. A variety chemicals have been shown to be effective 5 years after treatment; however, longer term trials of other formulations suggests that performance declines rapidly at longer time points. Field trials of remedial treatments for field drilled bolt holes continue to demonstrate the performance of diffusible boron and fluoride for preventing fungal attack. These trials will be evaluated again in the coming year. Inspection of the above ground region of Douglas-fir poles in the Pacific Northwest have shown that many poles are colonized by decay fungi far above the groundline. Fungal incidence was greatest in poles near the coast, but decay fungi were also isolated from poles in drier climates. Sampling of additional poles is planned to provide a more detailed analysis of the risk of above ground decay in this region. Efforts are also continuing to evaluate the performance of through-bored Douglas-fir poles to provide better data on the degree of preservative penetration required in the through-bored zone to achieve optimum performance. These trials have shown that most poles are well treated, but no decay has been detected in the through bored zone of poles with as little as 60 % of the through-bored zone treated. Efforts are also underway to evaluate penetration and retention of preservative in poles with various throughboring patterns. Studies to identify optimum conditions for sterilization of air-seasoned Douglas-fir poles are continuing. These trials have evaluated pentachlorophenol in oil treatments. The results illustrate the value of long treatment cycles which incorporate Boulton-seasoning. The data from these trials will be used to construct heating curves for this treatment. Trials of groundline preservative systems on Douglas-fir pole stubs continue to show that more recently developed formulations continue to move through the wood at rates which are similar to those found with older pentachlorophenol based systems. Trials in California on pine, Douglas-fir and western redcedar have provided similar results. Tests are now underway to establish thresholds for mixtures of groundline preservative formulations. Copper naphthenate treated wood continues to perform well in both field and fungal cellar trials. Unweathered western redcedar stakes have tended to perform better than stakes which were weathered prior to treatment. These differences may reflect an increased permeability which enhances leaching. Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1993 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) Evaluation of previously established field trials of internal remedial treatments continues to verify the excellent long-term protection afforded by these treatments. Field trials with gell encapsulated methylisothiocyanate (MITC) demonstrate that gelatin does not interfere with chemical release, nor is addition of supplemental moisture required for release. Field trials have been established to evaluate several new formulations including Basamid plus copper, boron/fluoride rods, and boron rods. Field trials of gelled and pelletized metham sodium indicate that both formulations are moving well through Douglas-fir poles one year after treatment. Evaluations of a copper naphthenate/boron paste for internal treatment indicate that the formulation has moved a short distance from the point of application 3 years after treatment. Boron rod field trials were not fully sampled for residual chemical level this past year; however, evaluation of cores removed from fused borate rod trials in New York indicate that some additional boron diffusion has occurred. Examination of treatment holes suggests that considerable amounts of the boron remain in rod form 2 years after application. In laboratory studies, we have evaluated the use of metham sodium/basamid mixtures and have found that these formulations provide enhanced MITC production over longer periods than either of the components alone. Both formulations were solid, creating the potential for development of safer formulations which provide a rapid release with long term protection. Field trials of these systems will be established in the coming months. Studies also continue with Basamid in an effort to enhance decomposition of this compound. Studies have shown that moisture addition has the most significant effect on decomposition followed by the presence of copper and increasing pH. Further studies on decomposition products are planned to better understand the activity of this molecule. Examination of Douglas-fir timbers treated with metham sodium indicate that MITC levels are similar to those found in poles at similar times after treatment. The presence increased surface area on timbers apparently did not adversely affect diffusion or chemical loss. Evaluation of the fungitoxicity of mixtures of MITC and carbon disulfide is underway in an effort better understand the activity of metham sodium. This compound decomposes to produce a wide array of volatile compounds with varying degrees of toxicity to fungi. Preliminary trials have shown the relatively low toxicity associated with carbon disulfide, a major decomposition product, particularly under acidic conditions. Trials with mixtures will begin shortly. Efforts to develop a three dimensional model of MITC movement are continuing. The model has been evaluated on data collected from small blocks and efforts are underway to verify these results. In addition, full pole grids have been prepared to evaluate the effects of treatment hole geometry and orientation on fumigant movement. Studies to identify alternative treatments for protecting western redcedar sapwood from decay are continuing. A variety chemicals have been shown to be effective 5 years after treatment; however, longer term trials of other formulations suggests that performance declines rapidly at longer time points. Field trials of remedial treatments for field drilled bolt holes continue to demonstrate the performance of diffusible boron and fluoride for preventing fungal attack. These trials will be evaluated again in the coming year. Inspection of the above ground region of Douglas-fir poles in the Pacific Northwest have shown that many poles are colonized by decay fungi far above the groundline. Fungal incidence was greatest in poles near the coast, but decay fungi were also isolated from poles in drier climates. Sampling of additional poles is planned to provide a more detailed analysis of the risk of above ground decay in this region. Efforts are also continuing to evaluate the performance of through-bored Douglas-fir poles to provide better data on the degree of preservative penetration required in the through-bored zone to achieve optimum performance. These trials have shown that most poles are well treated, but no decay has been detected in the through bored zone of poles with as little as 60 % of the through-bored zone treated. Efforts are also underway to evaluate penetration and retention of preservative in poles with various throughboring patterns. Studies to identify optimum conditions for sterilization of air-seasoned Douglas-fir poles are continuing. These trials have evaluated pentachlorophenol in oil treatments. The results illustrate the value of long treatment cycles which incorporate Boulton-seasoning. The data from these trials will be used to construct heating curves for this treatment. Trials of groundline preservative systems on Douglas-fir pole stubs continue to show that more recently developed formulations continue to move through the wood at rates which are similar to those found with older pentachlorophenol based systems. Trials in California on pine, Douglas-fir and western redcedar have provided similar results. Tests are now underway to establish thresholds for mixtures of groundline preservative formulations. Copper naphthenate treated wood continues to perform well in both field and fungal cellar trials. Unweathered western redcedar stakes have tended to perform better than stakes which were weathered prior to treatment. These differences may reflect an increased permeability which enhances leaching. Close

• 3893. [Article] Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; October 1996

  The Cooperative continues to actively address a diverse array of issues related to the effective use of wood utility poles. The trials to evaluate the effectiveness of MITC-Fume are now in their seventh ...

  Citation × Citation Citation Abstract Copy Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; October 1996 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) The Cooperative continues to actively address a diverse array of issues related to the effective use of wood utility poles. The trials to evaluate the effectiveness of MITC-Fume are now in their seventh year and continue to show that methylisothiocyanate (MITC) levels in MITC-Fume treatments remain higher than comparable metham sodium treatments. The levels of chemical are, however, declining, suggesting that this treatment may need replenishment in 3 to 5 years. Trials with the solid wood fumigant Basamid continue to show that MITC release can be enhanced by addition of small amounts of copper. Field trials suggest that these additives become less important with time. As a result, unamended Basamid may be suitable for treatment where the risk of immediate decay is not high, but the utility wishes to protect against future attack. Field trials with various water-diffusible internal treatments continue to show that these treatments move more slowly through Douglas-fir heartwood than do fumigants. Boron levels in pole sections treated with fused borate rods remain at levels that will protect against fungal attack 6 years after treatment. Similar trials with a boron/ fluoride rod indicate that neither fluoride or boron levels in the poles are adequate for wood protection 2 years after treatment. While the dosages tested were relatively low, the volumes of chemical were similar to the liquid volumes normally applied during internal remedial treatment. We will sample these poles next year to ensure that our measurements accurately reflect the chemical levels present. Trials to evaluate the effects of glycol on boron movement from fused borate rods suggest that glycol enhanced boron diffusion to only a slight extent. This effect was most pronounced at lower moisture contents. This trial was established to identify methods for improving boron movement in drier wood. In addition, moisture measurements in these poles suggest the internal wood moisture content varies widely both seasonally and positionally. While elevated moisture levels can negatively affect the movement of gaseous fumigants, excess moisture is critical for diffusion of boron or fluoride and its absence around the treatment site can markedly reduce the efficacy of rod treatments. These poles will continue to be monitored to assess both boron movement and seasonal changes in moisture content. Trials to identify safe, effective and easily used systems for protecting wood exposed during field fabrication are continuing. Boron and fluoride continue to provide excellent protection to field drilled bolt holes. These treatments are safe and easy to apply, and have provided protection in our field test for 14 years. Trials of similar formulations on simulated decking are also reported to provide additional information on the ability of boron and fluoride to protect exposed Douglas-fir heartwood. Efforts to improve the effectiveness of through boring as a method for enhancing the treatment of Douglas-fir poles are continuing. This past year, we evaluated preservative distribution around through bored holes as a means of developing optimum through boring patterns that maximized treatment while minimizing potential strength effects. These trials suggest the diamond shaped through boring zone of effect is relatively narrow. This information will be used in the coming year to construct optimum patterns for poles of various classes. The goal of this project is to develop a standard through boring pattern that would permit automation of the process. This would create the potential for cost savings on new poles. Trials to evaluate the durability of western redcedar are nearly complete. These trials were initiated because of concerns that second growth western redcedar might be less durable than poles cut from older trees. As expected, cedar varied widely in its resistance to fungal attack. This resistance, however, was not related to tree age, suggesting that there might not be a difference between so-called "old-growth" and "second growth" material. These data will be more thoroughly analyzed once the final set of trials are completed. In addition, we are evaluating more rapid methods for assessing cedar durability by measuring tropolone content. Tropolones are an important component of the extractives that make cedar heartwood so durable. Field trials of various externally applied supplemental groundline treatments are continuing at sites in Oregon, California, and New York. Trials in Corvallis, Oregon, have shown that various copper naphthenate, fluoride or boron based systems are at least as effective as the pentachlorophenol (penta) based systems that were formerly used for this purpose. Penta concentrations in one system have now declined below a protective level, while the copper based systems continue to remain at a protective level. Field trials in California are following similar trends and indicate that the alternative systems will provide comparable performance. Fungus cellar trials of copper naphthenate treated western redcedar stakes continue to show that this chemical provides excellent protection to cedar sapwood. Weathered wood that was treated with copper naphthenate continues to perform more poorly than freshly sawn wood treated to similar retention levels. Variations in permeability likely account for these differences. A new Wood Pole Maintenance Manual has been completed and is now ready for distribution. This update of the 1979 publication includes more information on initial pole procurement and closely follows the video by the same name that we produced in 1994. Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; October 1996 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) The Cooperative continues to actively address a diverse array of issues related to the effective use of wood utility poles. The trials to evaluate the effectiveness of MITC-Fume are now in their seventh year and continue to show that methylisothiocyanate (MITC) levels in MITC-Fume treatments remain higher than comparable metham sodium treatments. The levels of chemical are, however, declining, suggesting that this treatment may need replenishment in 3 to 5 years. Trials with the solid wood fumigant Basamid continue to show that MITC release can be enhanced by addition of small amounts of copper. Field trials suggest that these additives become less important with time. As a result, unamended Basamid may be suitable for treatment where the risk of immediate decay is not high, but the utility wishes to protect against future attack. Field trials with various water-diffusible internal treatments continue to show that these treatments move more slowly through Douglas-fir heartwood than do fumigants. Boron levels in pole sections treated with fused borate rods remain at levels that will protect against fungal attack 6 years after treatment. Similar trials with a boron/ fluoride rod indicate that neither fluoride or boron levels in the poles are adequate for wood protection 2 years after treatment. While the dosages tested were relatively low, the volumes of chemical were similar to the liquid volumes normally applied during internal remedial treatment. We will sample these poles next year to ensure that our measurements accurately reflect the chemical levels present. Trials to evaluate the effects of glycol on boron movement from fused borate rods suggest that glycol enhanced boron diffusion to only a slight extent. This effect was most pronounced at lower moisture contents. This trial was established to identify methods for improving boron movement in drier wood. In addition, moisture measurements in these poles suggest the internal wood moisture content varies widely both seasonally and positionally. While elevated moisture levels can negatively affect the movement of gaseous fumigants, excess moisture is critical for diffusion of boron or fluoride and its absence around the treatment site can markedly reduce the efficacy of rod treatments. These poles will continue to be monitored to assess both boron movement and seasonal changes in moisture content. Trials to identify safe, effective and easily used systems for protecting wood exposed during field fabrication are continuing. Boron and fluoride continue to provide excellent protection to field drilled bolt holes. These treatments are safe and easy to apply, and have provided protection in our field test for 14 years. Trials of similar formulations on simulated decking are also reported to provide additional information on the ability of boron and fluoride to protect exposed Douglas-fir heartwood. Efforts to improve the effectiveness of through boring as a method for enhancing the treatment of Douglas-fir poles are continuing. This past year, we evaluated preservative distribution around through bored holes as a means of developing optimum through boring patterns that maximized treatment while minimizing potential strength effects. These trials suggest the diamond shaped through boring zone of effect is relatively narrow. This information will be used in the coming year to construct optimum patterns for poles of various classes. The goal of this project is to develop a standard through boring pattern that would permit automation of the process. This would create the potential for cost savings on new poles. Trials to evaluate the durability of western redcedar are nearly complete. These trials were initiated because of concerns that second growth western redcedar might be less durable than poles cut from older trees. As expected, cedar varied widely in its resistance to fungal attack. This resistance, however, was not related to tree age, suggesting that there might not be a difference between so-called "old-growth" and "second growth" material. These data will be more thoroughly analyzed once the final set of trials are completed. In addition, we are evaluating more rapid methods for assessing cedar durability by measuring tropolone content. Tropolones are an important component of the extractives that make cedar heartwood so durable. Field trials of various externally applied supplemental groundline treatments are continuing at sites in Oregon, California, and New York. Trials in Corvallis, Oregon, have shown that various copper naphthenate, fluoride or boron based systems are at least as effective as the pentachlorophenol (penta) based systems that were formerly used for this purpose. Penta concentrations in one system have now declined below a protective level, while the copper based systems continue to remain at a protective level. Field trials in California are following similar trends and indicate that the alternative systems will provide comparable performance. Fungus cellar trials of copper naphthenate treated western redcedar stakes continue to show that this chemical provides excellent protection to cedar sapwood. Weathered wood that was treated with copper naphthenate continues to perform more poorly than freshly sawn wood treated to similar retention levels. Variations in permeability likely account for these differences. A new Wood Pole Maintenance Manual has been completed and is now ready for distribution. This update of the 1979 publication includes more information on initial pole procurement and closely follows the video by the same name that we produced in 1994. Close

• 3894. [Article] Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1987

  This seventh annual report outlines our continued progress on each of six objectives. Improved fumigants: We continue to evaluate previously established field tests, which inlicate that chioropicrin continues ...

  Citation × Citation Citation Abstract Copy Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1987 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) This seventh annual report outlines our continued progress on each of six objectives. Improved fumigants: We continue to evaluate previously established field tests, which inlicate that chioropicrin continues to protect Douglas-fir poles after 17 years and piling after 12 years. Vorlex treated poles are being gradually recolonized by decay fungi, while the Vapam treated poles appear to have little resistance to decay fungi. The latter poles were retreated last summer and will be used to determine the effectiveness of fumigant retreatment. Solid methylisothiocyanate (NIT) continues to protect Douglasfir poles, although the 20 percent NIT treatment has experienced slightly higher levels of colonization after 9 years. Additional tests to evaluate the effectiveness of gelatin encapsulated MIT or chioropicrin indicate that both chemicals continue to remain effective. In addition, there now appears to be little difference between the levels of control exhibited following addition of varying amounts of water to the poles along with gelatin encapsulated NIT. Closed tube bioassays indicate the chioropicrin remains at fungitoxic levels after 17 years, while no volatile fungitoxins appear to be present in Vapam or Vorlex treated wood. The evaluation of untreated Douglas-fir posts treated with NIT, chloropicrin, or Vapam indicate that fumigants can not ccatletely protect untreated wood in ground contact unless there is sane other type of preservative treated barrier present. Although the NIT treatment provided the best protection, all of the posts experienced some surface decay and termite attack after 10 years. These results appear similar to those found with more recent tests of posts treated with various coLthinations of preservative containing wraps and fuinigants. Evaluation of Mylone and tridipain, two solid chemicals that degrade to produce NIT, initcates that NIT production and fungal control are enhanced by the addition of basic pH buffers; however, only the pH 12 buffer resulted in rapid fungal control. These results Jnitcate that the rate of fumigant release can be tailored to control specific decay problems. We have also investigated the decomposition of Vapam in wood. As previously reported, there are over 14 potential deccmposition products from this chemical. This past year we developed methods for assaying these chemicals, evaluated the long-term stability of each, and prepared test blocks for evaluating decc*,osjtion in wood. In addition, we have studied the migration of volatile compounds from Vapam and NIT treated blocks under controlled aeration. After 5,000 hours, detectable levesis of NIT, carbon disulfide, and carbon oxysulfide are still present in air surrounding the Douglas-fir blocks. These tests indicate that low levels of volatile chemicals are continuously eninitted from fumigant treated wood. While this poses little difficulty for utility poles, it may pose some hazard for wood in closed spaces. Evaluations will continue until the emission levels decline below detectable limits. In addition to Vapam deccmposition studies, we have also evaluated the decoxrosition, movement and fungitoxicity of NIT under a variety of environmental conditions. In general, wet wood held less NIT, but the degree of control produced was more rapid. These results suggest that dry wood will act as a reseivoir of NIT, which will be released as moisture enters and swells the wood. This effect may provide an excellent long-term decay control strategy. The information from these studies will be used to develop more 111 ecific recaimrndations for fumigant treatment. Cedar Saood Decay Control: This past year we reestablished the field test of promising nei pentachiorophenol replacements, incorporating 26 chemicals into these tests. These saitles will be evaluated after 1 and 2 years to determine efficacy. In addition to the field test, we evaluated 13 new formulations or cinations of formulations in our laboratory screening tests. A nuner of chemicals including Isothiazolone, Amical 48 and a nurrer of quaternary aimnonium compounds appear promising and have been included in the field test. Bolt Hole Decay Prevention: Test established 5 years ago to determine the effectiveness of sprays, liquids or pastes applied to field drilled bolts holes indicate that airanonium bifluoride, Boracol 40, and 10% penta provided greater protection than Polybor or Patox washers. In addition, no evidence of corrosion was associated with any of the treatments. Fumigant treatments below the bolt holes continue to eliminate decay fungi, although samples removed from further down the pole indicate an incoIr)1ete distribution of MIT. These tests will be reevaluated this coming year. Detecting Early Decay and Estimating Residual Strength: We continue to evaluate the use of fluorescent coupled lectins and infra-red spectroscopy for detecting fungi in wood and early decay under controlled laboratory conditions. We have also continued evaluation of longitudinal compression (L) as a measure of ultite wood strength using a series of 27 Ldgepole pine posts. While the dense knot clusters interferred with the analysis, LCS, in combination with other parameters, was a reasonably good predictor of bending strength. These tests will continue with more uniform material. iv In addition to tests of LCS, we have evaluated the ability of small scal e tests to determine the strength of various wood pole connectors. Out results were in close agreement with those obtained using full scale tests aii illustrate the value of using small r1 e tests to develop strength information. Initiation of Decay in Air-Seasoning Douglas-fir: We continue to evaluate the data developed in the air-seasoning st1wies. This past year we began to develop information on the effects of various colony sizes on wood strength. This data will help us assign strength values to the colony size data we ha developed frau the air-seasoning study. At present, only Peniophora spp. has been tested, but . carbonica, P. placenta, and Haematostereum sanguinolentuin will also be included. Evaluation of the teinperatures required to eliminate fungi from Douglas-f ir poles also continue. We have ccatpleted 9 test charges which indicate that the penta treatmants involving a Boulton-seasoning cycle result in a ixre than adequate heating of the wood, while steam treants associated with amnniacal copper arsenate are nre variable. We feel that longer heating periods are required for poles greater than 12 inches in diamater, but that the current 6 hour steam period will result in heating of the center to 67 C for over 1 hour in smaller poles. Microfungi in Douglas-fir Poles: We continue to evaluate the effects of nticrofungi on properties of fumigant treated Douglas-fir poles. These tests indicate that prior colonization of fumigant treated wood by Scytalidium or Trichoderma species resulted in lower weight losses by P. placenta and . carbonica. Evaluation of a Cellon treated Douglas-fir laminated beam indicated that V severe penta depletion was associated with virtually all of the surface decay present. This beam had only been in service for 12 years in an extremely dry climate arxl it is unclear why the decay was so rapid. Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1987 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) This seventh annual report outlines our continued progress on each of six objectives. Improved fumigants: We continue to evaluate previously established field tests, which inlicate that chioropicrin continues to protect Douglas-fir poles after 17 years and piling after 12 years. Vorlex treated poles are being gradually recolonized by decay fungi, while the Vapam treated poles appear to have little resistance to decay fungi. The latter poles were retreated last summer and will be used to determine the effectiveness of fumigant retreatment. Solid methylisothiocyanate (NIT) continues to protect Douglasfir poles, although the 20 percent NIT treatment has experienced slightly higher levels of colonization after 9 years. Additional tests to evaluate the effectiveness of gelatin encapsulated MIT or chioropicrin indicate that both chemicals continue to remain effective. In addition, there now appears to be little difference between the levels of control exhibited following addition of varying amounts of water to the poles along with gelatin encapsulated NIT. Closed tube bioassays indicate the chioropicrin remains at fungitoxic levels after 17 years, while no volatile fungitoxins appear to be present in Vapam or Vorlex treated wood. The evaluation of untreated Douglas-fir posts treated with NIT, chloropicrin, or Vapam indicate that fumigants can not ccatletely protect untreated wood in ground contact unless there is sane other type of preservative treated barrier present. Although the NIT treatment provided the best protection, all of the posts experienced some surface decay and termite attack after 10 years. These results appear similar to those found with more recent tests of posts treated with various coLthinations of preservative containing wraps and fuinigants. Evaluation of Mylone and tridipain, two solid chemicals that degrade to produce NIT, initcates that NIT production and fungal control are enhanced by the addition of basic pH buffers; however, only the pH 12 buffer resulted in rapid fungal control. These results Jnitcate that the rate of fumigant release can be tailored to control specific decay problems. We have also investigated the decomposition of Vapam in wood. As previously reported, there are over 14 potential deccmposition products from this chemical. This past year we developed methods for assaying these chemicals, evaluated the long-term stability of each, and prepared test blocks for evaluating decc*,osjtion in wood. In addition, we have studied the migration of volatile compounds from Vapam and NIT treated blocks under controlled aeration. After 5,000 hours, detectable levesis of NIT, carbon disulfide, and carbon oxysulfide are still present in air surrounding the Douglas-fir blocks. These tests indicate that low levels of volatile chemicals are continuously eninitted from fumigant treated wood. While this poses little difficulty for utility poles, it may pose some hazard for wood in closed spaces. Evaluations will continue until the emission levels decline below detectable limits. In addition to Vapam deccmposition studies, we have also evaluated the decoxrosition, movement and fungitoxicity of NIT under a variety of environmental conditions. In general, wet wood held less NIT, but the degree of control produced was more rapid. These results suggest that dry wood will act as a reseivoir of NIT, which will be released as moisture enters and swells the wood. This effect may provide an excellent long-term decay control strategy. The information from these studies will be used to develop more 111 ecific recaimrndations for fumigant treatment. Cedar Saood Decay Control: This past year we reestablished the field test of promising nei pentachiorophenol replacements, incorporating 26 chemicals into these tests. These saitles will be evaluated after 1 and 2 years to determine efficacy. In addition to the field test, we evaluated 13 new formulations or cinations of formulations in our laboratory screening tests. A nuner of chemicals including Isothiazolone, Amical 48 and a nurrer of quaternary aimnonium compounds appear promising and have been included in the field test. Bolt Hole Decay Prevention: Test established 5 years ago to determine the effectiveness of sprays, liquids or pastes applied to field drilled bolts holes indicate that airanonium bifluoride, Boracol 40, and 10% penta provided greater protection than Polybor or Patox washers. In addition, no evidence of corrosion was associated with any of the treatments. Fumigant treatments below the bolt holes continue to eliminate decay fungi, although samples removed from further down the pole indicate an incoIr)1ete distribution of MIT. These tests will be reevaluated this coming year. Detecting Early Decay and Estimating Residual Strength: We continue to evaluate the use of fluorescent coupled lectins and infra-red spectroscopy for detecting fungi in wood and early decay under controlled laboratory conditions. We have also continued evaluation of longitudinal compression (L) as a measure of ultite wood strength using a series of 27 Ldgepole pine posts. While the dense knot clusters interferred with the analysis, LCS, in combination with other parameters, was a reasonably good predictor of bending strength. These tests will continue with more uniform material. iv In addition to tests of LCS, we have evaluated the ability of small scal e tests to determine the strength of various wood pole connectors. Out results were in close agreement with those obtained using full scale tests aii illustrate the value of using small r1 e tests to develop strength information. Initiation of Decay in Air-Seasoning Douglas-fir: We continue to evaluate the data developed in the air-seasoning st1wies. This past year we began to develop information on the effects of various colony sizes on wood strength. This data will help us assign strength values to the colony size data we ha developed frau the air-seasoning study. At present, only Peniophora spp. has been tested, but . carbonica, P. placenta, and Haematostereum sanguinolentuin will also be included. Evaluation of the teinperatures required to eliminate fungi from Douglas-f ir poles also continue. We have ccatpleted 9 test charges which indicate that the penta treatmants involving a Boulton-seasoning cycle result in a ixre than adequate heating of the wood, while steam treants associated with amnniacal copper arsenate are nre variable. We feel that longer heating periods are required for poles greater than 12 inches in diamater, but that the current 6 hour steam period will result in heating of the center to 67 C for over 1 hour in smaller poles. Microfungi in Douglas-fir Poles: We continue to evaluate the effects of nticrofungi on properties of fumigant treated Douglas-fir poles. These tests indicate that prior colonization of fumigant treated wood by Scytalidium or Trichoderma species resulted in lower weight losses by P. placenta and . carbonica. Evaluation of a Cellon treated Douglas-fir laminated beam indicated that V severe penta depletion was associated with virtually all of the surface decay present. This beam had only been in service for 12 years in an extremely dry climate arxl it is unclear why the decay was so rapid. Close

• 3895. [Article] Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1990

  Evaluations of previously established field trials indicate that chioropicrin, and Vorlex continue to provide protection to Douglas-fir poles, although the degree of protection is diminishing. Reapplication ...

  Citation × Citation Citation Abstract Copy Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1990 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) Evaluations of previously established field trials indicate that chioropicrin, and Vorlex continue to provide protection to Douglas-fir poles, although the degree of protection is diminishing. Reapplication of Vapam 18 years after the initial application eliminated fungi which had recolonized the poles. Methylisothiocyanate (MITC) continues to protect Douglas-fir poles 12 years after application. Gelatin encapsulation of MITC or chioropicrin appears to have no negative influence on fungitoxicity of these chemicals. Application of water to decompose the gelatin accelerated initial chemical release, but had no longterm effects on performance. A series of laboratory trials have been established to evaluate the performance of sodium n-methyldithiocarbamate (NaMDC), the active ingredient of Vapam. This chemical decomposes more slowly than the liquid formulations and a number of additives are being evaluated to accelerated decomposition. Along with the solid NaMDC, a pelletized formulation of Vapam was evaluated which contained 15 or 40 % NaMDC. These evaluations indicated that the addition of water accelerates release, but the fungal survival in these tests was more variable. The results suggest that a dosage 2 times greater than the liquid formulation is required for effective fungal control; however, further tests are planned to confirm these results. The evaluations of MITC-FUME in Douglas-fir and southern pine poles indicated that MITC has moved to a greater extent in Douglas-fir. Both closed tube bioassays and gas chromatographic analyses of ethyl acetate extracts of wood samples indicated that MITC was present at higher levels in Douglas-fir poles. Southern pine is far more permeable than Douglas-fir and MITC movement should be more rapid in this species. Further tests are planned to identify the nature of this delayed movement. 11 Evaluations of Dazomet, a crystalline solid which decomposes tO produce MITC in wood, indicate that detectable levels of this chemical are present in virtually all of the treatment groups. The decomposition rate of this chemical is normally too slow for effective fungal control and these trials are examining the ability of various additives to accelerate decomposition. Further evaluations of pole sections treated with Dazomet and selected additives are underway. A study to evaluate the effect of voids on fumigant effectivness suggests that voids do not adversely affect MITC movement through Douglas-fir pole sections. These results indicate that treatment of voids should be costeffective if the chemical is not applied directly to the void and if the pole retains a sufficient degree of strength. We continue to develop and refine a model for simulating the movement of MITC through Douglas-fir under varying temperature and moisture conditions. The model has been improved to permit three dimensional evaluations, but the times required for computation are still somewhat long. Further evaluations using a variety of environmental conditions are planned. Evaluations of potential replacements for pentachiorophenol for treatment of western redcedar sapwood and field drilled bolt holes have identified several promising alternatives. These chemicals are now under study in several modified field and laboratory tests. Field trials of several potential treatments for field drilled bolt holes indicate that Boracol 40, disodium octaborate tetrahydrate and ammonium bifluoride provided excellent protection over an 8 year period. These formulations all are relatively safe and can be easily applied in the field. 111 A laboratory trial to evaluate the effects of selected basidiomycetes on strength of Douglas-fir sapwood and heartwood has concluded. Fungal density, measured as the average number of fungi colonies per beam, gradually increased in all of the beams while longitudinal compression strength (LCS), modulus of rupture (MOR), and modulus of elesticity (MOE) slowly declined. Of the measurements, LCS appeared to be most useful, probably owing to the increased number of sampling sites per beam. The results indicate that the degree of colonization was not a good indicator of wood strength effects. The value of kerfing for decreasing post-treatment checking and improving the service life of Douglas-fir poles was evaluated using a series of inspection reports from a local utility. Kerfed transmission poles had substantially lower rates of internal decay and rejection, but there appeared to be little difference in the rate of decay between kerfed and non-kerfed distribution poles. The evaluation of disodium octaborate tetrahydrate for preventing colonization of air-seasoning Douglas-fir pole sections has been completed. Spraying with a 10 % boric acid equivalent solution (BAE) at 6 month intervals provided the greatest degree of protection, although dipping in a 20 % BAE solution at the start of air-seasoning produced a similar degree of protection. As expected, fungal colonization was far lower at the dryer Oroville site and borate treatment had little influence on the degree of fungal colonization at this site. The results indicate that borate treatment at the start of airseasoning is a viable method for limiting fungal colonization in moist airseasoning sites west of the Cascade Mountains. Evaluations of the tolerance of Stereum sanguinolentum and Peniophora spp. to elevated temperature exposures indicated that both of these fungi were extremely sensitive to elevated temperatures. The lack of long-term survival structures in these fungi probably accounts for this susceptibility to heat. iv A series of trials which measured internal temperatures in Douglas-fir pole sections during treatment with ammoniacal copper arsenate were used to develop a model for predicting internal heating during steaming. The results indicated that previous heating curves were overly optimistic in their prediction of heating. A series of heating curves for various pole diameters and starting conditions are presented. A number of externally applied groundline treatments are under evaluation in a field trial at Peavy Arboretum and a second trial will be established in the San Francisco Bay area. Seven formulations (including standards) are included. The Peavy site will be sampled in the next few months. The performance of copper naphthenate in western wood species is being evaluated in a series of small western redcedar sapwood stakelets which have been treated to a range of retentions and exposed in the fungus cellar. The results will be used to help confirm the performance of copper naphthenate in this species. Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1990 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) Evaluations of previously established field trials indicate that chioropicrin, and Vorlex continue to provide protection to Douglas-fir poles, although the degree of protection is diminishing. Reapplication of Vapam 18 years after the initial application eliminated fungi which had recolonized the poles. Methylisothiocyanate (MITC) continues to protect Douglas-fir poles 12 years after application. Gelatin encapsulation of MITC or chioropicrin appears to have no negative influence on fungitoxicity of these chemicals. Application of water to decompose the gelatin accelerated initial chemical release, but had no longterm effects on performance. A series of laboratory trials have been established to evaluate the performance of sodium n-methyldithiocarbamate (NaMDC), the active ingredient of Vapam. This chemical decomposes more slowly than the liquid formulations and a number of additives are being evaluated to accelerated decomposition. Along with the solid NaMDC, a pelletized formulation of Vapam was evaluated which contained 15 or 40 % NaMDC. These evaluations indicated that the addition of water accelerates release, but the fungal survival in these tests was more variable. The results suggest that a dosage 2 times greater than the liquid formulation is required for effective fungal control; however, further tests are planned to confirm these results. The evaluations of MITC-FUME in Douglas-fir and southern pine poles indicated that MITC has moved to a greater extent in Douglas-fir. Both closed tube bioassays and gas chromatographic analyses of ethyl acetate extracts of wood samples indicated that MITC was present at higher levels in Douglas-fir poles. Southern pine is far more permeable than Douglas-fir and MITC movement should be more rapid in this species. Further tests are planned to identify the nature of this delayed movement. 11 Evaluations of Dazomet, a crystalline solid which decomposes tO produce MITC in wood, indicate that detectable levels of this chemical are present in virtually all of the treatment groups. The decomposition rate of this chemical is normally too slow for effective fungal control and these trials are examining the ability of various additives to accelerate decomposition. Further evaluations of pole sections treated with Dazomet and selected additives are underway. A study to evaluate the effect of voids on fumigant effectivness suggests that voids do not adversely affect MITC movement through Douglas-fir pole sections. These results indicate that treatment of voids should be costeffective if the chemical is not applied directly to the void and if the pole retains a sufficient degree of strength. We continue to develop and refine a model for simulating the movement of MITC through Douglas-fir under varying temperature and moisture conditions. The model has been improved to permit three dimensional evaluations, but the times required for computation are still somewhat long. Further evaluations using a variety of environmental conditions are planned. Evaluations of potential replacements for pentachiorophenol for treatment of western redcedar sapwood and field drilled bolt holes have identified several promising alternatives. These chemicals are now under study in several modified field and laboratory tests. Field trials of several potential treatments for field drilled bolt holes indicate that Boracol 40, disodium octaborate tetrahydrate and ammonium bifluoride provided excellent protection over an 8 year period. These formulations all are relatively safe and can be easily applied in the field. 111 A laboratory trial to evaluate the effects of selected basidiomycetes on strength of Douglas-fir sapwood and heartwood has concluded. Fungal density, measured as the average number of fungi colonies per beam, gradually increased in all of the beams while longitudinal compression strength (LCS), modulus of rupture (MOR), and modulus of elesticity (MOE) slowly declined. Of the measurements, LCS appeared to be most useful, probably owing to the increased number of sampling sites per beam. The results indicate that the degree of colonization was not a good indicator of wood strength effects. The value of kerfing for decreasing post-treatment checking and improving the service life of Douglas-fir poles was evaluated using a series of inspection reports from a local utility. Kerfed transmission poles had substantially lower rates of internal decay and rejection, but there appeared to be little difference in the rate of decay between kerfed and non-kerfed distribution poles. The evaluation of disodium octaborate tetrahydrate for preventing colonization of air-seasoning Douglas-fir pole sections has been completed. Spraying with a 10 % boric acid equivalent solution (BAE) at 6 month intervals provided the greatest degree of protection, although dipping in a 20 % BAE solution at the start of air-seasoning produced a similar degree of protection. As expected, fungal colonization was far lower at the dryer Oroville site and borate treatment had little influence on the degree of fungal colonization at this site. The results indicate that borate treatment at the start of airseasoning is a viable method for limiting fungal colonization in moist airseasoning sites west of the Cascade Mountains. Evaluations of the tolerance of Stereum sanguinolentum and Peniophora spp. to elevated temperature exposures indicated that both of these fungi were extremely sensitive to elevated temperatures. The lack of long-term survival structures in these fungi probably accounts for this susceptibility to heat. iv A series of trials which measured internal temperatures in Douglas-fir pole sections during treatment with ammoniacal copper arsenate were used to develop a model for predicting internal heating during steaming. The results indicated that previous heating curves were overly optimistic in their prediction of heating. A series of heating curves for various pole diameters and starting conditions are presented. A number of externally applied groundline treatments are under evaluation in a field trial at Peavy Arboretum and a second trial will be established in the San Francisco Bay area. Seven formulations (including standards) are included. The Peavy site will be sampled in the next few months. The performance of copper naphthenate in western wood species is being evaluated in a series of small western redcedar sapwood stakelets which have been treated to a range of retentions and exposed in the fungus cellar. The results will be used to help confirm the performance of copper naphthenate in this species. Close

• 3896. [Article] Forest associations and secondary plant succession in the southern Oregon coastal range

  Forest associations, secondary succession, and relationships of plant communities to Roosevelt elk were investigated. Stratification of vegetation into ecological units and an understanding of secondary succession ...

  Citation × Citation Citation Abstract Copy Title: Forest associations and secondary plant succession in the southern Oregon coastal range Author: Bailey, Arthur Wesley, 1938- Forest associations, secondary succession, and relationships of plant communities to Roosevelt elk were investigated. Stratification of vegetation into ecological units and an understanding of secondary succession by habitat-type were a necessary first step in investigations into browsing of conifers by elk. The study was jointly conducted by the Oregon State Game Commission and the Weyerhaeuser Company. Vegetation, soils, and physiography were studied together. Vegetation cover data, recorded in thirty-two, 275 to 500-year-old forest stands, formed the basis of a synecological classification. Lightspots are a natural component of these forests. The dense forest and a lightspot were separately sampled in each stand. Light-spot cover data were analyzed separately in an association table. Lightspot data were compared with dense forest data to check validity of the phytosociological classification. This approach increased phytosociological understanding of these forests. The climax dominant tree and shrub and herb layer species with highest cover are used in naming the following associations (in order of increasing xerism): Thuja/Adiantum-Athyrium Tsuga/Polystichum/Oxalis Tsuga/Acer/Berberis Tsuga-Pseudotsuga/Rhododendron/Berberis Pseudotsuga/Holodiscus/Gaultheria. The exceptions are Adiantum pedatum and Athyrium filix-femina, high constancy, low cover, indicator species, used in naming the Thuja/Adiantum-Athyrium association. Polystichum munitum and Oxalis oregana dominate the herb layer of this association. Associations will be referred to in the abstract by a two-part name. The Adiantum-Athyrium association has the following additional indicator species: Blechnum spicant and Marah oreganus. Stands usually occur near the bottoms of lower elevation canyons. The moist, stony, Slickrock soil series underlies most stands. The Polystichum/Oxalis association is the most widespread and variable community studied. Tiarella trifoliata has high indicator value for this association. The presence of any one of Stellaria crispa, Montia sibirica, Dicentra formosa or Athyrium filix-femina in lightspots effectively differentiates stands of this association from related ones of the Acer/Berberis association. Stands frequently occur on lower and middle slopes and are usually underlain by the Matson or Apt soil series. In the Acer/Berberis association, Acer circinatum has high cover only in lightspots. Most stands are found on the Millicoma or Matson soil series. Stands occur on lower and middle slopes. Stands of the Rhododendron/Berberis association usually occur on south-facing, upper slopes and ridgetops where high winds frequently cause blowdown. The resultant large openings allow regeneration of Pseudotsuga menziesii. Rhododendron macrophyllum has low cover in the dense forest but high cover in lightspots. Allotropa virgata, a low constancy (saprophyte), has high fidelity to the association. The Millicoma, Matson or Ivers soil series underlie most stands. The Holodiscus/Gaultheria association has the following high fidelity species: Philadelphus lewisii, Symphoricarpos mollis, Madia gracilis, Hierochloe occidentalis, Ligusticum apiifolium, and Lonicera hispidula. This is the only association studied in which the lightspot phenomenon was not important. With the exception of Pseudotsuga menziesii regeneration, understory vegetation did not increase in cover when the tree canopy was removed. Stands usually occur on south-facing, upper slopes and ridgetops. The Digger or Agony soil series are associated with most stands. The successional influence of soil-surface disturbance caused by logging was studied in 1 to 15-year-old stands of the Polystichum/Oxalis and Rhododendron/Berberis habitat-types. In the Polystichum/Oxalis habitat-type, the vegetative dominants by years since logging are: Senecio sylvaticus--first year; Deschampsia elongata--years 2 to 4; Aira caryophyllea, Rubus ursinus, Hypochaeris radicata and Crepis capillaris share dominance--years 5 to 9; Hypochaeris radicata and Pteridium aquilinum share dominance--years 10 to 15. Pseudotsuga menziesii increased to 16 percent cover in the 10 to 15-year period. Disturbed areas of the Rhododendron/Berberis habitat-type have more than 65 percent bare ground for two years after logging. The vegetation dominants by years are: Deschampsia elongata--years 3 to 4; Hypochaeris radicata and Rubus ursinus--years 5 to 7; and Pseudotsuga menziesii--years 8 to 15. Other high cover species in the 8 to 15-year period are Thermopsis montana, Rubus ursinus, and Pteridium aquilinum. Selected stages in secondary succession were studied from one year after logging to climax in the two most important habitat-types. In the Polystichum/Oxalis habitat-type, Pseudotsuga menziesii is the seral tree dominant but is replaced by Tsuga heterophylla in climax. The tall shrub Acer circinatum has high cover in those serai stages with a comparatively open tree canopy. The herb layer is dominated throughout secondary succession by Polystichum munitum and Oxalis oregana. The tree layer of serai stands of the Rhododendron/Berberis habitat-type is dominated by Pseudotsuga menziesii. Either Tsuga heterophylla or Pseudotsuga menziesii dominate near-climax stands. The shrub layer dominant is Rhododendron macrophyllum throughout secondary succession. It has low cover in the dense forest but high cover in lightspots of near-climax stands. Berberis nervosa has nearly constant coverage throughout secondary succession in the Rhododendron/Berberis habitat-type and is the herb layer dominant in near-climax stands. Herb layer dominants in early serai stages are: Senecio sylvaticus--year 1; Erechtites prenanthoides--year 2; Rubus ursinus and Gaultheria shallon--years 4-15. Classification and recognition of habitat-types are possible throughout secondary succession from logging to climax on the basis of the same indicator species. The dominance level of some species changes with seral stage, but the change is predictable. Preferred elk food is about twice as abundant in the Polystichum/Oxalis as the Rhododendron/Berberis habitat-type. Nutritious, preferred elk food is most available in the 4 to 9-year period of secondary succession. Present logging methods which leave a mosaic of intermingled disturbed and undisturbed areas create a habitat beneficial to elk. The animals forage on disturbed areas for preferred invader species and on adjacent undisturbed areas for forest remnant species. Title: Forest associations and secondary plant succession in the southern Oregon coastal range Author: Bailey, Arthur Wesley, 1938- Forest associations, secondary succession, and relationships of plant communities to Roosevelt elk were investigated. Stratification of vegetation into ecological units and an understanding of secondary succession by habitat-type were a necessary first step in investigations into browsing of conifers by elk. The study was jointly conducted by the Oregon State Game Commission and the Weyerhaeuser Company. Vegetation, soils, and physiography were studied together. Vegetation cover data, recorded in thirty-two, 275 to 500-year-old forest stands, formed the basis of a synecological classification. Lightspots are a natural component of these forests. The dense forest and a lightspot were separately sampled in each stand. Light-spot cover data were analyzed separately in an association table. Lightspot data were compared with dense forest data to check validity of the phytosociological classification. This approach increased phytosociological understanding of these forests. The climax dominant tree and shrub and herb layer species with highest cover are used in naming the following associations (in order of increasing xerism): Thuja/Adiantum-Athyrium Tsuga/Polystichum/Oxalis Tsuga/Acer/Berberis Tsuga-Pseudotsuga/Rhododendron/Berberis Pseudotsuga/Holodiscus/Gaultheria. The exceptions are Adiantum pedatum and Athyrium filix-femina, high constancy, low cover, indicator species, used in naming the Thuja/Adiantum-Athyrium association. Polystichum munitum and Oxalis oregana dominate the herb layer of this association. Associations will be referred to in the abstract by a two-part name. The Adiantum-Athyrium association has the following additional indicator species: Blechnum spicant and Marah oreganus. Stands usually occur near the bottoms of lower elevation canyons. The moist, stony, Slickrock soil series underlies most stands. The Polystichum/Oxalis association is the most widespread and variable community studied. Tiarella trifoliata has high indicator value for this association. The presence of any one of Stellaria crispa, Montia sibirica, Dicentra formosa or Athyrium filix-femina in lightspots effectively differentiates stands of this association from related ones of the Acer/Berberis association. Stands frequently occur on lower and middle slopes and are usually underlain by the Matson or Apt soil series. In the Acer/Berberis association, Acer circinatum has high cover only in lightspots. Most stands are found on the Millicoma or Matson soil series. Stands occur on lower and middle slopes. Stands of the Rhododendron/Berberis association usually occur on south-facing, upper slopes and ridgetops where high winds frequently cause blowdown. The resultant large openings allow regeneration of Pseudotsuga menziesii. Rhododendron macrophyllum has low cover in the dense forest but high cover in lightspots. Allotropa virgata, a low constancy (saprophyte), has high fidelity to the association. The Millicoma, Matson or Ivers soil series underlie most stands. The Holodiscus/Gaultheria association has the following high fidelity species: Philadelphus lewisii, Symphoricarpos mollis, Madia gracilis, Hierochloe occidentalis, Ligusticum apiifolium, and Lonicera hispidula. This is the only association studied in which the lightspot phenomenon was not important. With the exception of Pseudotsuga menziesii regeneration, understory vegetation did not increase in cover when the tree canopy was removed. Stands usually occur on south-facing, upper slopes and ridgetops. The Digger or Agony soil series are associated with most stands. The successional influence of soil-surface disturbance caused by logging was studied in 1 to 15-year-old stands of the Polystichum/Oxalis and Rhododendron/Berberis habitat-types. In the Polystichum/Oxalis habitat-type, the vegetative dominants by years since logging are: Senecio sylvaticus--first year; Deschampsia elongata--years 2 to 4; Aira caryophyllea, Rubus ursinus, Hypochaeris radicata and Crepis capillaris share dominance--years 5 to 9; Hypochaeris radicata and Pteridium aquilinum share dominance--years 10 to 15. Pseudotsuga menziesii increased to 16 percent cover in the 10 to 15-year period. Disturbed areas of the Rhododendron/Berberis habitat-type have more than 65 percent bare ground for two years after logging. The vegetation dominants by years are: Deschampsia elongata--years 3 to 4; Hypochaeris radicata and Rubus ursinus--years 5 to 7; and Pseudotsuga menziesii--years 8 to 15. Other high cover species in the 8 to 15-year period are Thermopsis montana, Rubus ursinus, and Pteridium aquilinum. Selected stages in secondary succession were studied from one year after logging to climax in the two most important habitat-types. In the Polystichum/Oxalis habitat-type, Pseudotsuga menziesii is the seral tree dominant but is replaced by Tsuga heterophylla in climax. The tall shrub Acer circinatum has high cover in those serai stages with a comparatively open tree canopy. The herb layer is dominated throughout secondary succession by Polystichum munitum and Oxalis oregana. The tree layer of serai stands of the Rhododendron/Berberis habitat-type is dominated by Pseudotsuga menziesii. Either Tsuga heterophylla or Pseudotsuga menziesii dominate near-climax stands. The shrub layer dominant is Rhododendron macrophyllum throughout secondary succession. It has low cover in the dense forest but high cover in lightspots of near-climax stands. Berberis nervosa has nearly constant coverage throughout secondary succession in the Rhododendron/Berberis habitat-type and is the herb layer dominant in near-climax stands. Herb layer dominants in early serai stages are: Senecio sylvaticus--year 1; Erechtites prenanthoides--year 2; Rubus ursinus and Gaultheria shallon--years 4-15. Classification and recognition of habitat-types are possible throughout secondary succession from logging to climax on the basis of the same indicator species. The dominance level of some species changes with seral stage, but the change is predictable. Preferred elk food is about twice as abundant in the Polystichum/Oxalis as the Rhododendron/Berberis habitat-type. Nutritious, preferred elk food is most available in the 4 to 9-year period of secondary succession. Present logging methods which leave a mosaic of intermingled disturbed and undisturbed areas create a habitat beneficial to elk. The animals forage on disturbed areas for preferred invader species and on adjacent undisturbed areas for forest remnant species. Close

• 3897. [Article] Patterns of crown damage within a large wildfire in the Klamath-Siskiyou bioregion

  The 2002 Biscuit Fire burned through more than 200,000 ha of mixed conifer/ evergreen hardwood forests in southwestern Oregon and northwestern California. The remarkable size of the fire and the diversity ...

  Citation × Citation Citation Abstract Copy Title: Patterns of crown damage within a large wildfire in the Klamath-Siskiyou bioregion Author: Thompson, Jonathan R. The 2002 Biscuit Fire burned through more than 200,000 ha of mixed conifer/ evergreen hardwood forests in southwestern Oregon and northwestern California. The remarkable size of the fire and the diversity of conditions through which it burned provided an opportunity to analyze the correlates of burn severity across vegetation types and disturbance histories and to describe the weather, topographical, and fuel conditions that gave rise to the mosaic of crown damage. In chapter two, I focused on a region that had burned previously by the 1987 Silver Fire then was subject, in part, to salvage-logging and conifer planting before being reburned by the Biscuit Fire. I used the Landsat-based differenced normalized burn ratio (dNBR) to quantify severity in both fires and took a hypothesis-testing approach to answering two questions: First, was severity in the Biscuit Fire associated with severity in the Silver Fire in unmanaged areas? And second, did areas that were salvaged-logged and planted with conifers after the Silver Fire burn more or less severely in the Biscuit Fire than comparable unmanaged areas? I found that areas that burned severely in 1987 tended to re-burn at high severity in 2002, after controlling for the influence of several topographical and biophysical covariates. Areas unaffected by the initial fire tended to burn at the lowest severities in 2002. In addition, areas that were salvage-logged and planted after the initial fire burned more severely than comparable unmanaged areas, suggesting that post-fire logging and planting did not reduce future fire severity as had been suggested by some. In chapter three, I again focused on the twice-burned landscape, but this time I used a temporal sequence of digital aerial photography plots (6.25 ha) to measure changes in shrub-stratum, hardwood, and conifer cover. I estimated the strength and nature of relationships between crown damage and several fuel, topographical, weather, and management variables. Median crown damage, including damage to the shrub-stratum, on unmanaged plots was 63% after the Biscuit Fire and was most strongly related to damage in the Silver Fire. Plots that burned severely in the Silver Fire and had succeeded to a mix of shrubs and tree regeneration experienced high levels of Biscuit Fire damage. Plots dominated by large conifer cover after the Silver Fire had the lowest levels of Biscuit Fire canopy damage. Median crown damage was 39% for conifer cover and 85% for hardwood cover, and was most strongly related to daily average temperature and "burn period," an index of fire weather and fire suppression effort. Damage in the tree-stratum was largely independent of Silver Fire severity. Plots that had experienced stand replacing fire in 1987 and then were logged and planted with conifers had median crown damage of 100%. Plots that experienced a stand replacing fire but were unmanaged had median crown damage of 95%. The managed areas were at higher topographical positions and had greater total pre-fire cover, which may explain the small difference. These results suggest that in productive, fire-prone landscapes, the patch mosaic of young regenerating forest created by mixed-severity fire can structure the severity pattern of future wildfires occurring at short intervals and support the previous studies findings that post-fire logging and planting did not reduce fire severity. In Chapter four, I expanded my focus to include the entire region burned by the Biscuit Fire and again used digital aerial photos taken before and after the fire to interpret patterns of crown damage and relate them to several fuel, topographical, weather, and management variables. Ninety-eight percent of plots experienced some level of crown damage, but only 10% experienced complete crown damage. The median level of crown damage on unmanaged plots was 74%. Median conifer damage was 52%. The most important predictors of total crown damage were the percentage of pre-fire shrub-stratum vegetation cover and average daily temperature. The most important predictors of conifer damage were average daily temperature and burn period. Increasing levels of shrub-stratum cover were associated with increasing levels of conifer damage and hardwood damage. Large conifers had 32% median crown damage while small conifers had 62% median crown damage. Owing largely to widespread shrub-stratum cover, low-productivity ultramafic soils had 92% median crown damage compared to 59% on non-ultramafic sites. Patterns of damage were similar within the area that burned previously in the 1987 Silver Fire and edaphically comparable areas without a recently history of fire. Median crown damage in conifer plantations was 89% and plantation age was, by far, the most important predictor of the level of damage. Plantations under 20 years old experienced the highest rates of damage. I conclude that weather and vegetation conditions--not topography--were the primary determinants of Biscuit Fire crown damage. These findings suggest that in productive fire-prone ecosystems, fuel treatments that open tree canopies and stimulate shrub-stratum development may be counterproductive. Title: Patterns of crown damage within a large wildfire in the Klamath-Siskiyou bioregion Author: Thompson, Jonathan R. The 2002 Biscuit Fire burned through more than 200,000 ha of mixed conifer/ evergreen hardwood forests in southwestern Oregon and northwestern California. The remarkable size of the fire and the diversity of conditions through which it burned provided an opportunity to analyze the correlates of burn severity across vegetation types and disturbance histories and to describe the weather, topographical, and fuel conditions that gave rise to the mosaic of crown damage. In chapter two, I focused on a region that had burned previously by the 1987 Silver Fire then was subject, in part, to salvage-logging and conifer planting before being reburned by the Biscuit Fire. I used the Landsat-based differenced normalized burn ratio (dNBR) to quantify severity in both fires and took a hypothesis-testing approach to answering two questions: First, was severity in the Biscuit Fire associated with severity in the Silver Fire in unmanaged areas? And second, did areas that were salvaged-logged and planted with conifers after the Silver Fire burn more or less severely in the Biscuit Fire than comparable unmanaged areas? I found that areas that burned severely in 1987 tended to re-burn at high severity in 2002, after controlling for the influence of several topographical and biophysical covariates. Areas unaffected by the initial fire tended to burn at the lowest severities in 2002. In addition, areas that were salvage-logged and planted after the initial fire burned more severely than comparable unmanaged areas, suggesting that post-fire logging and planting did not reduce future fire severity as had been suggested by some. In chapter three, I again focused on the twice-burned landscape, but this time I used a temporal sequence of digital aerial photography plots (6.25 ha) to measure changes in shrub-stratum, hardwood, and conifer cover. I estimated the strength and nature of relationships between crown damage and several fuel, topographical, weather, and management variables. Median crown damage, including damage to the shrub-stratum, on unmanaged plots was 63% after the Biscuit Fire and was most strongly related to damage in the Silver Fire. Plots that burned severely in the Silver Fire and had succeeded to a mix of shrubs and tree regeneration experienced high levels of Biscuit Fire damage. Plots dominated by large conifer cover after the Silver Fire had the lowest levels of Biscuit Fire canopy damage. Median crown damage was 39% for conifer cover and 85% for hardwood cover, and was most strongly related to daily average temperature and "burn period," an index of fire weather and fire suppression effort. Damage in the tree-stratum was largely independent of Silver Fire severity. Plots that had experienced stand replacing fire in 1987 and then were logged and planted with conifers had median crown damage of 100%. Plots that experienced a stand replacing fire but were unmanaged had median crown damage of 95%. The managed areas were at higher topographical positions and had greater total pre-fire cover, which may explain the small difference. These results suggest that in productive, fire-prone landscapes, the patch mosaic of young regenerating forest created by mixed-severity fire can structure the severity pattern of future wildfires occurring at short intervals and support the previous studies findings that post-fire logging and planting did not reduce fire severity. In Chapter four, I expanded my focus to include the entire region burned by the Biscuit Fire and again used digital aerial photos taken before and after the fire to interpret patterns of crown damage and relate them to several fuel, topographical, weather, and management variables. Ninety-eight percent of plots experienced some level of crown damage, but only 10% experienced complete crown damage. The median level of crown damage on unmanaged plots was 74%. Median conifer damage was 52%. The most important predictors of total crown damage were the percentage of pre-fire shrub-stratum vegetation cover and average daily temperature. The most important predictors of conifer damage were average daily temperature and burn period. Increasing levels of shrub-stratum cover were associated with increasing levels of conifer damage and hardwood damage. Large conifers had 32% median crown damage while small conifers had 62% median crown damage. Owing largely to widespread shrub-stratum cover, low-productivity ultramafic soils had 92% median crown damage compared to 59% on non-ultramafic sites. Patterns of damage were similar within the area that burned previously in the 1987 Silver Fire and edaphically comparable areas without a recently history of fire. Median crown damage in conifer plantations was 89% and plantation age was, by far, the most important predictor of the level of damage. Plantations under 20 years old experienced the highest rates of damage. I conclude that weather and vegetation conditions--not topography--were the primary determinants of Biscuit Fire crown damage. These findings suggest that in productive fire-prone ecosystems, fuel treatments that open tree canopies and stimulate shrub-stratum development may be counterproductive. Close

• 3898. [Article] The legal and regulatory setting affecting timber supply on Oregon's public lands

  Graduation date:

  Citation × Citation Citation Abstract Copy Title: The legal and regulatory setting affecting timber supply on Oregon's public lands Author: Peckman, Nancy Graduation date: Title: The legal and regulatory setting affecting timber supply on Oregon's public lands Author: Peckman, Nancy Graduation date: Close

• 3899. [Article] Utilization of Low-value Lumber from Small-diameter Timber Harvested in Pacific Northwest Forest Restoration Programs in Hybrid Cross Laminated Timber (CLT) Core Layers: Technical Feasibility

  Each year the United States: Forest Service (USFS) spends billions of dollars fighting forest fires. One strategy used by the USFS to prevent catastrophic fires is through forest restoration programs, ...

  Citation × Citation Citation Abstract Copy Title: Utilization of Low-value Lumber from Small-diameter Timber Harvested in Pacific Northwest Forest Restoration Programs in Hybrid Cross Laminated Timber (CLT) Core Layers: Technical Feasibility Author: Lawrence, Christina Each year the United States: Forest Service (USFS) spends billions of dollars fighting forest fires. One strategy used by the USFS to prevent catastrophic fires is through forest restoration programs, in which potential forest fuel is removed through mechanized thinning. This program is expensive and generates high volumes of small-diameter logs (less than 6” at the small end). This material is often converted to low-value wood chips, pulp, or biomass. Some of these small-diameter logs can be processed in local specialized sawmills capable of processing it into lumber. What is not utilized locally from the restoration programs, is transported at a cost to the USFS to the nearest facilities that can use or process the produced products from the thinning. Creating a value-added product using low-grade lumber produced from small-diameter timber would improve the economic balance for forest restoration operation. The general aim of this research was to increase or stimulate markets for wood products utilizing low-value small-diameter material generated in National Forest System restoration programs. Our hypothesis is that low-value lumber cut from small-diameter logs (4”-6” at the small end) could be successfully utilized in core layers of structural cross laminated timber (CLT) panels. Cross -laminated timber is an engineered wood panel composed of solid-sawn lumber, such as 2x6 or 2x8, laid up in perpendicular directions and used as prefabricated walls and floors. However, to be qualified for structural uses, CLT must meet standard minimum bond integrity criteria specified by the North American product standard (ANSI/APA PRG 320-2012), determined through laboratory testing for delamination (≤5%) and shear resistance (≥80% wood failure). The objective of this project was to determine the feasibility of small-diameter logs harvested from National Forest System restoration programs in 3- and 5ply CLT panels. Adding value to low-value timber harvested from USFS lands by using it within CLT applications is expected to increase profitability of the harvested timber, offsetting costs for the restoration programs. The specific objectives were to: (1) build and test CLT panels utilizing lumber from forest restoration operations in core layers of panels against the certification criteria per PRG 320-2012 to allow low-grade lumber in cores of structural CLT; (2) based on findings, propose respective changes to the current North American standard PRG 320-2012; and (3) investigate the efficiency of the primary processing of small-logs from the thinnings and lamination options with lumber produced from these small logs. The approach was to incorporate the forest restoration material harvested in the larger Pacific Northwest region into the cores of 3- and 5-layer hybrid CLT panels and assess the technical viability of these panels by testing layup samples against the standard adhesive bond integrity criteria, and by comparing the characteristic engineering properties of the material (E, MOR, and rolling shear) with the standard CLT grade benchmarks. All tests were performed following the standard test protocols of the ANSI/APA PRG 320-2012. Blue Mountain Region of Eastern Oregon, and the Fremont-Winema forest in Southern Oregon were selected as representative forest restoration sites. The species harvested were Ponderosa pine, White fir, and Douglas-fir. The small logs processed at Idaho Forest Group (IFG) Lewiston, ID facility mainly produced a nominal 2x4, mostly No.2 & BTR visual grade lumber; Collins Co. donated Utility grade 2x4s. The 3- and 5-layer hybrid test panels were manufactured at D.R. Johnson in Riddle, OR consisting of No. 2 visual grade Douglas-fir as the panel’s faces and mixed species from the restoration thinnings in the core layers. The hybrid panels were used to determine E and MOR () using third-point bending, rolling shear ( through center-point bending, as well as adhesive bond integrity via block shear and cyclic delamination tests. In addition, 3- and 5-layer homogeneous panels consisting of Ponderosa pine, White fir and Douglas-fir were produced to detect and separate the potential effects of individual species on the adhesive bond integrity in the layups with mixed species in the core. These homogeneous panels were only used to determine the rolling shear strength in the core layers and to evaluate the integrity of the adhesive bonds. Homogeneous Douglas fir laminations constructed with standard lamstock used in commercial CLT production at DR Johnson were used as control material. The efficiency of primary and secondary manufacturing processes was also evaluated by company interviews and on-site visits. The control sample group, the homogeneous 3- and 5--ply No.2 visual grade Douglas-fir, met the minimum qualifications for the PRG 320-2012. The CLT test panels incorporating mixed species material from forest restoration programs in the core layers have shown good strength and elastic properties (compared to the standard E3 pre-defined CLT grade). However, in contrast to the reference commercial all Douglas-fir panels, none of the CLT panels with mixed species material from restoration programs passed the delamination test for bond integrity. Of the additional homogeneous layups, only 3-ply White fir combination passed the delamination test. Potential causes of failure might have been related to processing issues: 1) inconsistent thickness tolerances of laminations and 2) incompatibility of species-specific adhesive system with the species mix used in the tests. In the light of the current findings, none of the sample groups with material from forest restoration programs qualified for structural CLT per PRG 320-2012 standard criteria. Further investigation is needed to identify factors affecting the delamination failures, which both appear to be related to the manufacturing process and, thus, possible to mitigate. Regarding the efficiency of production of lumber and CLT panels from small logs, additional presorting during harvesting and mill processing steps may help increase process efficiencies during breakdown manufacturing steps. The efficiency of the IFG primary saw line was substantially lower when processing logs of diameters below 6 inches at the small end than normal production; however, with increased familiarity of the project’s thinned material, production efficiency should increase through additional pre-sorting and machine system settings. The economic feasibility side of using the harvested material conducted by Lawrence (2017), who found the material to not have significant to persuade CLT manufactures in the use of the material (Lawrence 2017). Title: Utilization of Low-value Lumber from Small-diameter Timber Harvested in Pacific Northwest Forest Restoration Programs in Hybrid Cross Laminated Timber (CLT) Core Layers: Technical Feasibility Author: Lawrence, Christina Each year the United States: Forest Service (USFS) spends billions of dollars fighting forest fires. One strategy used by the USFS to prevent catastrophic fires is through forest restoration programs, in which potential forest fuel is removed through mechanized thinning. This program is expensive and generates high volumes of small-diameter logs (less than 6” at the small end). This material is often converted to low-value wood chips, pulp, or biomass. Some of these small-diameter logs can be processed in local specialized sawmills capable of processing it into lumber. What is not utilized locally from the restoration programs, is transported at a cost to the USFS to the nearest facilities that can use or process the produced products from the thinning. Creating a value-added product using low-grade lumber produced from small-diameter timber would improve the economic balance for forest restoration operation. The general aim of this research was to increase or stimulate markets for wood products utilizing low-value small-diameter material generated in National Forest System restoration programs. Our hypothesis is that low-value lumber cut from small-diameter logs (4”-6” at the small end) could be successfully utilized in core layers of structural cross laminated timber (CLT) panels. Cross -laminated timber is an engineered wood panel composed of solid-sawn lumber, such as 2x6 or 2x8, laid up in perpendicular directions and used as prefabricated walls and floors. However, to be qualified for structural uses, CLT must meet standard minimum bond integrity criteria specified by the North American product standard (ANSI/APA PRG 320-2012), determined through laboratory testing for delamination (≤5%) and shear resistance (≥80% wood failure). The objective of this project was to determine the feasibility of small-diameter logs harvested from National Forest System restoration programs in 3- and 5ply CLT panels. Adding value to low-value timber harvested from USFS lands by using it within CLT applications is expected to increase profitability of the harvested timber, offsetting costs for the restoration programs. The specific objectives were to: (1) build and test CLT panels utilizing lumber from forest restoration operations in core layers of panels against the certification criteria per PRG 320-2012 to allow low-grade lumber in cores of structural CLT; (2) based on findings, propose respective changes to the current North American standard PRG 320-2012; and (3) investigate the efficiency of the primary processing of small-logs from the thinnings and lamination options with lumber produced from these small logs. The approach was to incorporate the forest restoration material harvested in the larger Pacific Northwest region into the cores of 3- and 5-layer hybrid CLT panels and assess the technical viability of these panels by testing layup samples against the standard adhesive bond integrity criteria, and by comparing the characteristic engineering properties of the material (E, MOR, and rolling shear) with the standard CLT grade benchmarks. All tests were performed following the standard test protocols of the ANSI/APA PRG 320-2012. Blue Mountain Region of Eastern Oregon, and the Fremont-Winema forest in Southern Oregon were selected as representative forest restoration sites. The species harvested were Ponderosa pine, White fir, and Douglas-fir. The small logs processed at Idaho Forest Group (IFG) Lewiston, ID facility mainly produced a nominal 2x4, mostly No.2 & BTR visual grade lumber; Collins Co. donated Utility grade 2x4s. The 3- and 5-layer hybrid test panels were manufactured at D.R. Johnson in Riddle, OR consisting of No. 2 visual grade Douglas-fir as the panel’s faces and mixed species from the restoration thinnings in the core layers. The hybrid panels were used to determine E and MOR () using third-point bending, rolling shear ( through center-point bending, as well as adhesive bond integrity via block shear and cyclic delamination tests. In addition, 3- and 5-layer homogeneous panels consisting of Ponderosa pine, White fir and Douglas-fir were produced to detect and separate the potential effects of individual species on the adhesive bond integrity in the layups with mixed species in the core. These homogeneous panels were only used to determine the rolling shear strength in the core layers and to evaluate the integrity of the adhesive bonds. Homogeneous Douglas fir laminations constructed with standard lamstock used in commercial CLT production at DR Johnson were used as control material. The efficiency of primary and secondary manufacturing processes was also evaluated by company interviews and on-site visits. The control sample group, the homogeneous 3- and 5--ply No.2 visual grade Douglas-fir, met the minimum qualifications for the PRG 320-2012. The CLT test panels incorporating mixed species material from forest restoration programs in the core layers have shown good strength and elastic properties (compared to the standard E3 pre-defined CLT grade). However, in contrast to the reference commercial all Douglas-fir panels, none of the CLT panels with mixed species material from restoration programs passed the delamination test for bond integrity. Of the additional homogeneous layups, only 3-ply White fir combination passed the delamination test. Potential causes of failure might have been related to processing issues: 1) inconsistent thickness tolerances of laminations and 2) incompatibility of species-specific adhesive system with the species mix used in the tests. In the light of the current findings, none of the sample groups with material from forest restoration programs qualified for structural CLT per PRG 320-2012 standard criteria. Further investigation is needed to identify factors affecting the delamination failures, which both appear to be related to the manufacturing process and, thus, possible to mitigate. Regarding the efficiency of production of lumber and CLT panels from small logs, additional presorting during harvesting and mill processing steps may help increase process efficiencies during breakdown manufacturing steps. The efficiency of the IFG primary saw line was substantially lower when processing logs of diameters below 6 inches at the small end than normal production; however, with increased familiarity of the project’s thinned material, production efficiency should increase through additional pre-sorting and machine system settings. The economic feasibility side of using the harvested material conducted by Lawrence (2017), who found the material to not have significant to persuade CLT manufactures in the use of the material (Lawrence 2017). Close

• 3900. [Article] Ecological effects of post-wildfire management activities (salvage-logging and grass-seeding) on vegetation composition, diversity, biomass, and growth and survival of Pinus ponderosa and Purshia tridentata

  Salvage-logging and artificial seeding of grass following wildfire are common practices in coniferous forests of the western United States, yet few studies have quantified the ecological effects of these ...

  Citation × Citation Citation Abstract Copy Title: Ecological effects of post-wildfire management activities (salvage-logging and grass-seeding) on vegetation composition, diversity, biomass, and growth and survival of Pinus ponderosa and Purshia tridentata Author: Sexton, Timothy Ogden Salvage-logging and artificial seeding of grass following wildfire are common practices in coniferous forests of the western United States, yet few studies have quantified the ecological effects of these post-fire activities. The effects of post-wildfire salvage-logging and grass-seeding on vegetation composition, aboveground biomass, and growth and survival of Pinus ponderosa and Purshia tridentata were quantified on the area burned by the 1992 Lone Pine Fire, Winema National Forest in the Klamath Basin, Oregon. Prior to the fire, the area was dominated by uneven-aged stands of Pinus ponderosa with Purshia tridentata and Stipa occidentalis in the understory. The fire was a stand-replacement disturbance, where the majority of trees, the herbaceous component, and crowns of understory shrubs were killed. Salvage logging resulted in a significant decrease in understory biomass, species richness, species diversity, and growth and survival of P. ponderosa and P. tridentata. In addition plant community composition was shifted from native forb dominance to grass dominance. In 1993, the understory biomass of salvage-logged sites was 38% of the aboveground biomass produced on nonsalvaged sites (322 kg ha^-1 vs 843 kg ha^-1). In 1994, salvage-logged sites produced only 27% of the biomass produced on nonsalvaged sites (402 kg ha^-1 vs 1468 kg ha^-1). Salvage-logging reduced species richness, species diversity, and altered species composition. The first and second years following logging, species richness was reduced by 13% (20 versus 23), and 30% (15 versus 22), respectively. In 1993 and 1994, native forb frequency on nonsalvaged sites was 80% and 77% respectively, while salvage-logged sites recorded 68% and 31% respectively. Conversely, graminoid frequency was significantly higher on salvage-logged sites. In 1994, native graminoid frequency was 35% in nonsalvaged sites and > 61% on salvage-logged sites. During the first two years following salvage-logging, mean height growth of naturally-regenerated Pinus ponderosa was significantly lower on salvaged sites (9.4 versus 7.8 cm yr^-1) as was density of natural Purshia tridentata seedlings (313 versus 530 seedlings ha^-1). Survival in salvage-logged treatments was 22% lower for planted Purshia tridentata seedlings (57% versus 45%). Height growth in salvage-logged treatments was 16% lower for planted Pinus ponderosa (4.4 versus 3.7 cm). Total aboveground biomass on nonsalvaged burned sites (controls) averaged 843 kg ha^-1 in 1993, and 1473 kg ha^-1 in 1994. In 1993, the first year following the fire, sites seeded to Secale cereale produced = 1995 kg ha^-1 total aboveground biomass; most of the biomass was S. cereale. Those seeded sites produced 89% less native forb biomass than controls (82 versus 780 kg ha^-1), and = 80% less native forb biomass than areas seeded to the native grasses Sitanion hystrix and Festuca idahoensis. In 1994, the second post-fire year, biomass on sites seeded to S. cereale was >1653 kg ha^-1, dominated by S. cereale. In 1994, no differences in total aboveground biomass were detected between S. cereale, F idahoensis, S. hystrix, and the Control, indicating that the erosion reducing benefits of grass-seeding did not last for more than one year. Treatments seeded with S. cereale produced 58% less native forb biomass than controls (350 versus 825 kg ha^-1). Seeding S. cereale also reduced by 69% the biomass ofStipa occidentalis, the most common native grass in the area (311 kg ha^-1 on control sites versus 96 kg ha^-1 on S. cereale sites). In 1993 and 1994, fewer species were recorded on S. cereale sites than on all other sites. Grass-seeded sites exhibited no significant differences in frequency of noxious weeds in either of the two years following wildfire and seeding, rejecting the hypothesis that grass-seeding reduces noxious weeds. However, native graminoid frequency was reduced on all grass-seeded treatments. There were no significant differences between grass-seeding treatments in height and density of natural P. ponderosa and P. tridentata seedlings or growth and survival of planted P. ponderosa and P. tridentata seedlings. While salvage-logging provides an economic benefit to local communities through the extraction of commercially valuable timber, there is an ecological cost. Reduction in ecosystem structure, production, species richness, diversity and alterations in species composition are important ecological consequences of salvage logging. In addition, this study demonstrates that salvage-logging retards the re-establishment and early growth of Pinus ponderosa and Purshia tridentata, two important wildfire restoration priorities. Grass-seeding also results in significant ecological changes. Alterations in ecosystem production, species richness, diversity and species composition are important ecological consequences of grass-seeding. Managers should consider these long-term influences on ecosystem composition and structure when faced with decisions concerning post-fire rehabilitation and management. Title: Ecological effects of post-wildfire management activities (salvage-logging and grass-seeding) on vegetation composition, diversity, biomass, and growth and survival of Pinus ponderosa and Purshia tridentata Author: Sexton, Timothy Ogden Salvage-logging and artificial seeding of grass following wildfire are common practices in coniferous forests of the western United States, yet few studies have quantified the ecological effects of these post-fire activities. The effects of post-wildfire salvage-logging and grass-seeding on vegetation composition, aboveground biomass, and growth and survival of Pinus ponderosa and Purshia tridentata were quantified on the area burned by the 1992 Lone Pine Fire, Winema National Forest in the Klamath Basin, Oregon. Prior to the fire, the area was dominated by uneven-aged stands of Pinus ponderosa with Purshia tridentata and Stipa occidentalis in the understory. The fire was a stand-replacement disturbance, where the majority of trees, the herbaceous component, and crowns of understory shrubs were killed. Salvage logging resulted in a significant decrease in understory biomass, species richness, species diversity, and growth and survival of P. ponderosa and P. tridentata. In addition plant community composition was shifted from native forb dominance to grass dominance. In 1993, the understory biomass of salvage-logged sites was 38% of the aboveground biomass produced on nonsalvaged sites (322 kg ha^-1 vs 843 kg ha^-1). In 1994, salvage-logged sites produced only 27% of the biomass produced on nonsalvaged sites (402 kg ha^-1 vs 1468 kg ha^-1). Salvage-logging reduced species richness, species diversity, and altered species composition. The first and second years following logging, species richness was reduced by 13% (20 versus 23), and 30% (15 versus 22), respectively. In 1993 and 1994, native forb frequency on nonsalvaged sites was 80% and 77% respectively, while salvage-logged sites recorded 68% and 31% respectively. Conversely, graminoid frequency was significantly higher on salvage-logged sites. In 1994, native graminoid frequency was 35% in nonsalvaged sites and > 61% on salvage-logged sites. During the first two years following salvage-logging, mean height growth of naturally-regenerated Pinus ponderosa was significantly lower on salvaged sites (9.4 versus 7.8 cm yr^-1) as was density of natural Purshia tridentata seedlings (313 versus 530 seedlings ha^-1). Survival in salvage-logged treatments was 22% lower for planted Purshia tridentata seedlings (57% versus 45%). Height growth in salvage-logged treatments was 16% lower for planted Pinus ponderosa (4.4 versus 3.7 cm). Total aboveground biomass on nonsalvaged burned sites (controls) averaged 843 kg ha^-1 in 1993, and 1473 kg ha^-1 in 1994. In 1993, the first year following the fire, sites seeded to Secale cereale produced = 1995 kg ha^-1 total aboveground biomass; most of the biomass was S. cereale. Those seeded sites produced 89% less native forb biomass than controls (82 versus 780 kg ha^-1), and = 80% less native forb biomass than areas seeded to the native grasses Sitanion hystrix and Festuca idahoensis. In 1994, the second post-fire year, biomass on sites seeded to S. cereale was >1653 kg ha^-1, dominated by S. cereale. In 1994, no differences in total aboveground biomass were detected between S. cereale, F idahoensis, S. hystrix, and the Control, indicating that the erosion reducing benefits of grass-seeding did not last for more than one year. Treatments seeded with S. cereale produced 58% less native forb biomass than controls (350 versus 825 kg ha^-1). Seeding S. cereale also reduced by 69% the biomass ofStipa occidentalis, the most common native grass in the area (311 kg ha^-1 on control sites versus 96 kg ha^-1 on S. cereale sites). In 1993 and 1994, fewer species were recorded on S. cereale sites than on all other sites. Grass-seeded sites exhibited no significant differences in frequency of noxious weeds in either of the two years following wildfire and seeding, rejecting the hypothesis that grass-seeding reduces noxious weeds. However, native graminoid frequency was reduced on all grass-seeded treatments. There were no significant differences between grass-seeding treatments in height and density of natural P. ponderosa and P. tridentata seedlings or growth and survival of planted P. ponderosa and P. tridentata seedlings. While salvage-logging provides an economic benefit to local communities through the extraction of commercially valuable timber, there is an ecological cost. Reduction in ecosystem structure, production, species richness, diversity and alterations in species composition are important ecological consequences of salvage logging. In addition, this study demonstrates that salvage-logging retards the re-establishment and early growth of Pinus ponderosa and Purshia tridentata, two important wildfire restoration priorities. Grass-seeding also results in significant ecological changes. Alterations in ecosystem production, species richness, diversity and species composition are important ecological consequences of grass-seeding. Managers should consider these long-term influences on ecosystem composition and structure when faced with decisions concerning post-fire rehabilitation and management. Close