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• 441. [Article] Plastome phylogenomics in the genus Pinus using massively parallel sequencing technology

  This thesis summarizes work completed over the previous four years primarily focusing on chloroplast phylogenomic inquiry into the genus Pinus and related Pinaceae outgroups using next-generation sequencing ...

  Citation × Citation Citation Abstract Copy Title: Plastome phylogenomics in the genus Pinus using massively parallel sequencing technology Author: Parks, Matthew Benjamin This thesis summarizes work completed over the previous four years primarily focusing on chloroplast phylogenomic inquiry into the genus Pinus and related Pinaceae outgroups using next-generation sequencing on Illumina platforms. During the time of our work, Illumina sequence read lengths have essentially been limited to 25 to 100 base pairs, presenting challenges when trying to assemble genomic space featuring repetitive regions or regions divergent from established reference genomes. Our assemblies initially relied on previously constructed high quality plastome sequences for each of the two Pinus subgenera, yet we were able to show clear negative trends in assembly success as divergence from reference sequences. This was most evident in assemblies of Pinaceae outgroups, but the trend was also apparent within Pinus subgenera. To counter this problem, we used a combination of de novo and reference-guided assembly approaches, which allowed us to more effectively assemble highly divergent regions. From a biological standpoint, our initial focus was on increasing phylogenetic resolution by using nearly complete plastome sequences from select Pinus and Pinaceae outgroup species. This effort indeed resulted in greatly increased phylogenetic resolution as evidenced by a nearly 60-fold increase in parsimony informative positions in our dataset as compared to previous datasets comprised of only several chloroplast loci. In addition, bootstrap support levels across the resulting phylogenetic tree were consistently high, with ≥95% bootstrap support at 30/33 ingroup nodes in maximum likelihood analysis. A positive correlation between the length/amount of sequence data applied to our phylogeny and overall bootstrap support values was also supported, although trends indicated some nodes would likely remain recalcitrant even with the application of complete plastomes. This correlation was important to demonstrate, as it was reflective of trends seen in a meta-analysis of contemporary, infrageneric chloroplast-based phylogenies. In addition, our meta-analysis indicated that most researchers rely on relatively small regions of the chloroplast genome in these studies and obtain relatively little in resolution and support in resulting phylogenies. Clearly, the application of plastome sequences to these types of analyses has great potential for increasing our understanding of evolutionary relationships at low taxonomic levels. An unexpected finding of this work involved two putative protein-coding regions in the chloroplast, ycf1 and ycf2, which featured strongly elevated rates of mutation, and together accounted for over half of exon parsimony informative sites although making up only 22% of exon sequence length. Of these two loci, clearly ycf1 was more problematic to assemble from short read data, as it featured numerous indels as well as several repetitive regions. We designed primers based on conserved regions allowing essentially complete amplification of this locus and sequenced the ycf1 locus (with Sanger technology) for a representative of each of the 11 Pinus subsections, using accessions from the previous study. Importantly, these primers were also effective across Pinaceae and should facilitate future work throughout the family. Accessions with full ycf1 sequences were in turn utilized as subsectional references as we sequenced and assembled plastomes for most of the remaining Pinus species. To efficiently produce these sequences, we relied on a solution-based hybridization strategy developed by Richard Cronn to enrich preparations of total genomic DNA for chloroplast-specific DNA. While the phylogenetic results of a full-plastome, full-genus analysis were certainly of interest, our final focus was on the investigation of ‘noise’ in our dataset, and whether it affected phylogenetic conclusions drawn from the plastome. To determine this, we explored the removal of variable sites from our alignment and the resultant effect on topology and resolution. This allowed us to identify a window of alignment partitions in which nodal bootstrap support remained high across the genus, yet sufficient noise was removed to identify important patterns in the positioning of three clades with historically problematic phylogenetic positioning. Title: Plastome phylogenomics in the genus Pinus using massively parallel sequencing technology Author: Parks, Matthew Benjamin This thesis summarizes work completed over the previous four years primarily focusing on chloroplast phylogenomic inquiry into the genus Pinus and related Pinaceae outgroups using next-generation sequencing on Illumina platforms. During the time of our work, Illumina sequence read lengths have essentially been limited to 25 to 100 base pairs, presenting challenges when trying to assemble genomic space featuring repetitive regions or regions divergent from established reference genomes. Our assemblies initially relied on previously constructed high quality plastome sequences for each of the two Pinus subgenera, yet we were able to show clear negative trends in assembly success as divergence from reference sequences. This was most evident in assemblies of Pinaceae outgroups, but the trend was also apparent within Pinus subgenera. To counter this problem, we used a combination of de novo and reference-guided assembly approaches, which allowed us to more effectively assemble highly divergent regions. From a biological standpoint, our initial focus was on increasing phylogenetic resolution by using nearly complete plastome sequences from select Pinus and Pinaceae outgroup species. This effort indeed resulted in greatly increased phylogenetic resolution as evidenced by a nearly 60-fold increase in parsimony informative positions in our dataset as compared to previous datasets comprised of only several chloroplast loci. In addition, bootstrap support levels across the resulting phylogenetic tree were consistently high, with ≥95% bootstrap support at 30/33 ingroup nodes in maximum likelihood analysis. A positive correlation between the length/amount of sequence data applied to our phylogeny and overall bootstrap support values was also supported, although trends indicated some nodes would likely remain recalcitrant even with the application of complete plastomes. This correlation was important to demonstrate, as it was reflective of trends seen in a meta-analysis of contemporary, infrageneric chloroplast-based phylogenies. In addition, our meta-analysis indicated that most researchers rely on relatively small regions of the chloroplast genome in these studies and obtain relatively little in resolution and support in resulting phylogenies. Clearly, the application of plastome sequences to these types of analyses has great potential for increasing our understanding of evolutionary relationships at low taxonomic levels. An unexpected finding of this work involved two putative protein-coding regions in the chloroplast, ycf1 and ycf2, which featured strongly elevated rates of mutation, and together accounted for over half of exon parsimony informative sites although making up only 22% of exon sequence length. Of these two loci, clearly ycf1 was more problematic to assemble from short read data, as it featured numerous indels as well as several repetitive regions. We designed primers based on conserved regions allowing essentially complete amplification of this locus and sequenced the ycf1 locus (with Sanger technology) for a representative of each of the 11 Pinus subsections, using accessions from the previous study. Importantly, these primers were also effective across Pinaceae and should facilitate future work throughout the family. Accessions with full ycf1 sequences were in turn utilized as subsectional references as we sequenced and assembled plastomes for most of the remaining Pinus species. To efficiently produce these sequences, we relied on a solution-based hybridization strategy developed by Richard Cronn to enrich preparations of total genomic DNA for chloroplast-specific DNA. While the phylogenetic results of a full-plastome, full-genus analysis were certainly of interest, our final focus was on the investigation of ‘noise’ in our dataset, and whether it affected phylogenetic conclusions drawn from the plastome. To determine this, we explored the removal of variable sites from our alignment and the resultant effect on topology and resolution. This allowed us to identify a window of alignment partitions in which nodal bootstrap support remained high across the genus, yet sufficient noise was removed to identify important patterns in the positioning of three clades with historically problematic phylogenetic positioning. Close

• 442. [Article] Identification of optimal broodstock for Pacific Northwest oysters

  The United States Pacific Northwest is well known for its shellfish farming. Historically, commercial harvests were dominated by the native Olympia oyster, Ostrea lurida, but over-exploitation, habitat ...

  Citation × Citation Citation Abstract Copy Title: Identification of optimal broodstock for Pacific Northwest oysters Author: Stick, David A. The United States Pacific Northwest is well known for its shellfish farming. Historically, commercial harvests were dominated by the native Olympia oyster, Ostrea lurida, but over-exploitation, habitat degradation, and competition and predation by non-native species has drastically depleted their densities and extirpated many local populations. As a result, shellfish aquaculture production has shifted to the introduced Pacific oyster, Crassostrea gigas. An underlying objective of this dissertation is the use of molecular genetics to improve our ability to accurately identifying optimal oyster broodstock for either restoration of Olympia oysters or farming of Pacific oysters. The ecological benefits provided by oysters as well as the Olympia oyster's historical significance, has motivated numerous restoration/supplementation efforts but these efforts are proceeding without a clear understanding of the genetic structure among extant populations, which could be substantial as a consequence of limited dispersal, local adaptation and/or anthropogenic impacts. To facilitate this understanding, we isolated and characterized 19 polymorphic microsatellites and used 8 of these to study the genetic structure of 2,712 individuals collected from 25 remnant Olympia oyster populations between the northern tip of Vancouver Island BC and Elkhorn Slough CA. Gene flow among geographically separated extant Olympia oyster populations is surprisingly limited for a marine invertebrate species whose free-swimming larvae are capable of planktonic dispersal as long as favorable water conditions exist. We found a significant correlation between geographic and genetic distances supporting the premise that coastal populations are isolated by distance. Genetic structure among remnant populations was not limited to broad geographic regions but was also present at sub-regional scales in both Puget Sound WA and San Francisco Bay CA. Until it can be determined whether genetically differentiated O. lurida populations are locally adapted, restoration projects and resource managers should be cautious of random mixing or transplantation of stocks where gene flow is restricted. As we transition from our Olympia oyster population analysis to our Pacific oyster quantitative analysis, we recognize that traditional quantitative trait locus (QTL) mapping strategies use crosses among inbred lines to create segregating populations. Unfortunately, even low levels of inbreeding in the Pacific oyster (Crassostrea gigas) can substantially depress economically important quantitative traits such as yield and survival, potentially complicating subsequent QTL analyses. To circumvent this problem, we constructed an integrated linkage map for Pacific oysters, consisting of 65 microsatellite (18 of which were previously unmapped) and 212 AFLP markers using a full-sib cross between phenotypically differentiated outbred families. We identified 10 linkage groups (LG1-LG10) spanning 710.48 cM, with an average genomic coverage of 91.39% and an average distance between markers of 2.62 cM. Average marker saturation was 27.7 per linkage group, ranging between 19 (LG9) and 36 markers (LG3). Using this map we identified 12 quantitative trait loci (QTLs) and 5 potential QTLs in the F1 outcross population of 236 full-sib Pacific oysters for four growth-related morphometric measures, including individual wet live weight, shell length, shell width and shell depth measured at four post-fertilization time points: plant-out (average age of 140 days), first year interim (average age of 358 days), second year interim (average age of 644 days) and harvest (average age of 950 days). Mapped QTLs and potential QTLs accounted for an average of 11.2% of the total phenotypic variation and ranged between 2.1 and 33.1%. Although QTL or potential QTL were mapped to all Pacific oyster linkage groups with the exception of LG2, LG8 and LG9, three groups (LG4, LG10 and LG5) were associated with three or more QTL or potential QTL. We conclude that alleles accounting for a significant proportion of the total phenotypic variation for morphometric measures that influence harvest yield remain segregating within the broodstock of West Coast Pacific oyster selective breeding programs. Title: Identification of optimal broodstock for Pacific Northwest oysters Author: Stick, David A. The United States Pacific Northwest is well known for its shellfish farming. Historically, commercial harvests were dominated by the native Olympia oyster, Ostrea lurida, but over-exploitation, habitat degradation, and competition and predation by non-native species has drastically depleted their densities and extirpated many local populations. As a result, shellfish aquaculture production has shifted to the introduced Pacific oyster, Crassostrea gigas. An underlying objective of this dissertation is the use of molecular genetics to improve our ability to accurately identifying optimal oyster broodstock for either restoration of Olympia oysters or farming of Pacific oysters. The ecological benefits provided by oysters as well as the Olympia oyster's historical significance, has motivated numerous restoration/supplementation efforts but these efforts are proceeding without a clear understanding of the genetic structure among extant populations, which could be substantial as a consequence of limited dispersal, local adaptation and/or anthropogenic impacts. To facilitate this understanding, we isolated and characterized 19 polymorphic microsatellites and used 8 of these to study the genetic structure of 2,712 individuals collected from 25 remnant Olympia oyster populations between the northern tip of Vancouver Island BC and Elkhorn Slough CA. Gene flow among geographically separated extant Olympia oyster populations is surprisingly limited for a marine invertebrate species whose free-swimming larvae are capable of planktonic dispersal as long as favorable water conditions exist. We found a significant correlation between geographic and genetic distances supporting the premise that coastal populations are isolated by distance. Genetic structure among remnant populations was not limited to broad geographic regions but was also present at sub-regional scales in both Puget Sound WA and San Francisco Bay CA. Until it can be determined whether genetically differentiated O. lurida populations are locally adapted, restoration projects and resource managers should be cautious of random mixing or transplantation of stocks where gene flow is restricted. As we transition from our Olympia oyster population analysis to our Pacific oyster quantitative analysis, we recognize that traditional quantitative trait locus (QTL) mapping strategies use crosses among inbred lines to create segregating populations. Unfortunately, even low levels of inbreeding in the Pacific oyster (Crassostrea gigas) can substantially depress economically important quantitative traits such as yield and survival, potentially complicating subsequent QTL analyses. To circumvent this problem, we constructed an integrated linkage map for Pacific oysters, consisting of 65 microsatellite (18 of which were previously unmapped) and 212 AFLP markers using a full-sib cross between phenotypically differentiated outbred families. We identified 10 linkage groups (LG1-LG10) spanning 710.48 cM, with an average genomic coverage of 91.39% and an average distance between markers of 2.62 cM. Average marker saturation was 27.7 per linkage group, ranging between 19 (LG9) and 36 markers (LG3). Using this map we identified 12 quantitative trait loci (QTLs) and 5 potential QTLs in the F1 outcross population of 236 full-sib Pacific oysters for four growth-related morphometric measures, including individual wet live weight, shell length, shell width and shell depth measured at four post-fertilization time points: plant-out (average age of 140 days), first year interim (average age of 358 days), second year interim (average age of 644 days) and harvest (average age of 950 days). Mapped QTLs and potential QTLs accounted for an average of 11.2% of the total phenotypic variation and ranged between 2.1 and 33.1%. Although QTL or potential QTL were mapped to all Pacific oyster linkage groups with the exception of LG2, LG8 and LG9, three groups (LG4, LG10 and LG5) were associated with three or more QTL or potential QTL. We conclude that alleles accounting for a significant proportion of the total phenotypic variation for morphometric measures that influence harvest yield remain segregating within the broodstock of West Coast Pacific oyster selective breeding programs. Close

• 443. [Article] Modeling abiotic influences on disease dynamics for the complex life cycle of the myxozoan parasite Ceratomyxa shasta

  Most parasites and their hosts live in a balance within their environment; however a disease outbreak can occur when either the parasite, host, or environment, are perturbed. Myxozoan parasites are associated ...

  Citation × Citation Citation Abstract Copy Title: Modeling abiotic influences on disease dynamics for the complex life cycle of the myxozoan parasite Ceratomyxa shasta Author: Ray, Robert Adam Most parasites and their hosts live in a balance within their environment; however a disease outbreak can occur when either the parasite, host, or environment, are perturbed. Myxozoan parasites are associated with a wide variety of cultured and wild fish populations. Most myxozoans are relatively benign to their vertebrate host; however some cause dramatic population level effects on both cultured and wild fish populations. These parasites have a complex life cycle involving a vertebrate host (fish), an invertebrate host (annelid), and two spore stages (actinospore and myxospore). Interactions between these parasites and their hosts can be strongly influenced by environmental factors, most notably by water temperature and water velocity. Given the complex life cycle of myxozoan parasites and the lack of any chemical treatments or preventatives, controlling infections and disease caused by these parasites is challenging, especially for wild populations. The myxozoan Ceratomyxa shasta is endemic to many of the major rivers of the Pacific Northwest and infects all species of Pacific salmon. In the Klamath River, CA, USA, C. shasta infection is associated with decreased returns of adult Chinook salmon (Oncorhynchus tshawytscha). The goals of this dissertation were to 1) quantify the effect that elevated water temperature has on C. shasta-induced disease severity and mortality rate for both Chinook and coho (O. kitsch) salmon, 2) identify transmission patterns and quantify transmission rates of the actinospore stage to the salmon host, 3) develop an epidemiological model of this host-parasite life cycle and assess the sensitivity of specific parameters that may act as suitable management strategies, and 4) utilize a mixture cure model, an alternative survival analysis method, to quantify the effects water temperature and discharge on the total and rate of C. shasta-induced mortality of both Chinook and coho salmon. I found that, similar to disease progression naïve salmon species (i.e. from waters where C. shasta is absent), elevated water temperature increases the rate and overall mortality for salmon species from river systems where the parasite is endemic. Elevated water temperatures also increase the transmission rate of the actinospore stage to the salmon host. The transmission rate of the actinospore stage to the salmon host was inversely related to water velocity, and I identified a potential velocity threshold of ~0.3m/sec, above which transmission was greatly reduced. From the epidemiological model I sensitivity analyses and identified that reduction of the myxospore transmission rate from the adult salmon to the polychaete host during the winter may be the most effective management action to reduce C. shasta-related disease in the Klamath River. This action could potentially be achieved by increasing discharge during the winter to minimize contact between the polychaete host and myxospore stage. Lastly, I applied the mixture cure models to quantify how the daily survival rates of Chinook and coho salmon change over time after the fish become infected with C. shasta. Although varied in approach, the output from both of the models presented in this dissertation can be used to guide management and conservation actions for fish populations affected by myxozoan parasites. Title: Modeling abiotic influences on disease dynamics for the complex life cycle of the myxozoan parasite Ceratomyxa shasta Author: Ray, Robert Adam Most parasites and their hosts live in a balance within their environment; however a disease outbreak can occur when either the parasite, host, or environment, are perturbed. Myxozoan parasites are associated with a wide variety of cultured and wild fish populations. Most myxozoans are relatively benign to their vertebrate host; however some cause dramatic population level effects on both cultured and wild fish populations. These parasites have a complex life cycle involving a vertebrate host (fish), an invertebrate host (annelid), and two spore stages (actinospore and myxospore). Interactions between these parasites and their hosts can be strongly influenced by environmental factors, most notably by water temperature and water velocity. Given the complex life cycle of myxozoan parasites and the lack of any chemical treatments or preventatives, controlling infections and disease caused by these parasites is challenging, especially for wild populations. The myxozoan Ceratomyxa shasta is endemic to many of the major rivers of the Pacific Northwest and infects all species of Pacific salmon. In the Klamath River, CA, USA, C. shasta infection is associated with decreased returns of adult Chinook salmon (Oncorhynchus tshawytscha). The goals of this dissertation were to 1) quantify the effect that elevated water temperature has on C. shasta-induced disease severity and mortality rate for both Chinook and coho (O. kitsch) salmon, 2) identify transmission patterns and quantify transmission rates of the actinospore stage to the salmon host, 3) develop an epidemiological model of this host-parasite life cycle and assess the sensitivity of specific parameters that may act as suitable management strategies, and 4) utilize a mixture cure model, an alternative survival analysis method, to quantify the effects water temperature and discharge on the total and rate of C. shasta-induced mortality of both Chinook and coho salmon. I found that, similar to disease progression naïve salmon species (i.e. from waters where C. shasta is absent), elevated water temperature increases the rate and overall mortality for salmon species from river systems where the parasite is endemic. Elevated water temperatures also increase the transmission rate of the actinospore stage to the salmon host. The transmission rate of the actinospore stage to the salmon host was inversely related to water velocity, and I identified a potential velocity threshold of ~0.3m/sec, above which transmission was greatly reduced. From the epidemiological model I sensitivity analyses and identified that reduction of the myxospore transmission rate from the adult salmon to the polychaete host during the winter may be the most effective management action to reduce C. shasta-related disease in the Klamath River. This action could potentially be achieved by increasing discharge during the winter to minimize contact between the polychaete host and myxospore stage. Lastly, I applied the mixture cure models to quantify how the daily survival rates of Chinook and coho salmon change over time after the fish become infected with C. shasta. Although varied in approach, the output from both of the models presented in this dissertation can be used to guide management and conservation actions for fish populations affected by myxozoan parasites. Close

• 444. [Article] Carbon Dynamics in Response to Land Cover Change in Tropical Peatlands, Kalimantan, Indonesia

  This study focuses in providing the knowledge on carbon (C) stocks, emission and ecosystem productivity related to land use/land cover change in tropical peatlands. The field research activities were ...

  Citation × Citation Citation Abstract Copy Title: Carbon Dynamics in Response to Land Cover Change in Tropical Peatlands, Kalimantan, Indonesia Author: Basuki, Imam This study focuses in providing the knowledge on carbon (C) stocks, emission and ecosystem productivity related to land use/land cover change in tropical peatlands. The field research activities were conducted for about 17 months between August 2013 to December 2015, at Pematang Gadung peat dome (peat depth up to 10.5 m), Ketapang Regency, West Kalimantan, Indonesia. The objectives of this study were: a). to quantify C stocks of tropical coastal peat swamp forest, and the potential impact of forest degradation due to draining and logging activities on the forest’s carbon stocks; b). to examine the change in ecosystem C stocks and the potential C emissions in relation to land conversion from intact peat swamp forest (PSF) to logged peat forest (LPSF), early seral (ES) and oil palm plantation (OP); and c). to estimate net primary production (NPP) and net ecosystem production (NEP) in peat swamp forests, logged peat forest, early seral and smallholder - oil palm plantations. The intact peat forest sites have higher total aboveground C stocks (125 Mg C ha-1) than the logged peat forest sites (77 Mg C ha-1). Mean depths of the LPSF was 725 cm and the PSF was 915 cm (p= 0.06). Mean peat carbon stocks at PSF was 4,243 Mg C ha-1, higher than at LPSF that was 3,675 Mg C ha-1. Logging and draining had reduced the biomass of trees and the peat carbon pools. My study demonstrated that tropical coastal PSF has the largest total carbon stocks among terrestrial ecosystems on earth. The large carbon stocks and high rates of PSF degradation, points to the relevance for inclusion of PSF in nationally appropriate climate change mitigation and adaptation strategies. The mean ecosystem carbon stock for the PSF sites was 4,401 Mg C ha-1. Ecosystem C stocks of LPSF, ES and OP was 3,768, 3,147, and 3,442 Mg C ha-1, respectively. PSF stocks was significantly higher than the degraded land covers. At all sites, soils comprised > 96% of the mean ecosystem carbon stock. Using the estimation based on ecosystem carbon loss to total peat depths, the conversion of PSF to LPSF, ES and OP was estimated to result in a net loss of 1,982, 4,259 and 3,176 Mg C-CO2 ha-1, respectively. My results confirm that land cover change significantly impacted soil properties and reduced ecosystem carbon stocks. The tropical peatlands need urgent and significant efforts in conservation and restoration, to regain its function as a C sink and mitigate climate change. I found that land use/land cover change resulted in large shifts in NPP and NEP. LPSF, ES and OP have significantly lower NPP (11.1 Mg C ha-1 yr-1, 10.8 Mg C ha-1 yr-1 and 3.7 Mg C ha-1 yr-1, respectively) than PSF (13.2 Mg C ha-1 yr-1). ES showed lower heterotrophic respiration (30.7 Mg CO2 ha-1 yr-1) than PSF, LPSF and OP (37.7 Mg CO2 ha-1 yr-1, 40.7 Mg CO2 ha-1 yr-1, 38.7 Mg CO2 ha-1 yr-1, respectively). LPSF and OP were net carbon sources; they have negative mean NEP values (-0.1 Mg CO2-e ha-1 yr-1 and -25.1 Mg CO2-e ha-1 yr-1, respectively). In contrast PSF and ES were net carbon sinks (10.8 Mg CO2-e ha-1 yr-1 and 9.1 CCO2 ha-1 yr-1, respectively). PSF is among the most productive of terrestrial ecosystems, with an NPP exceeding that of many tropical rain forests and similar to the most productive mangrove ecosystems. I found that land use decreases productivity of the LPSF and OP sites. The ES had a similar NEP to the PSF, but frequent fires in this ecosystem likely offset carbon gains during the fire intervals. Land use change and forest degradation have shifted tropical PSFs from net carbon sinks to net carbon sources. My study demonstrated that land conversion in tropical peat swamp forests should be halted and degraded peatlands need to be restored in order to mitigate climate change. Title: Carbon Dynamics in Response to Land Cover Change in Tropical Peatlands, Kalimantan, Indonesia Author: Basuki, Imam This study focuses in providing the knowledge on carbon (C) stocks, emission and ecosystem productivity related to land use/land cover change in tropical peatlands. The field research activities were conducted for about 17 months between August 2013 to December 2015, at Pematang Gadung peat dome (peat depth up to 10.5 m), Ketapang Regency, West Kalimantan, Indonesia. The objectives of this study were: a). to quantify C stocks of tropical coastal peat swamp forest, and the potential impact of forest degradation due to draining and logging activities on the forest’s carbon stocks; b). to examine the change in ecosystem C stocks and the potential C emissions in relation to land conversion from intact peat swamp forest (PSF) to logged peat forest (LPSF), early seral (ES) and oil palm plantation (OP); and c). to estimate net primary production (NPP) and net ecosystem production (NEP) in peat swamp forests, logged peat forest, early seral and smallholder - oil palm plantations. The intact peat forest sites have higher total aboveground C stocks (125 Mg C ha-1) than the logged peat forest sites (77 Mg C ha-1). Mean depths of the LPSF was 725 cm and the PSF was 915 cm (p= 0.06). Mean peat carbon stocks at PSF was 4,243 Mg C ha-1, higher than at LPSF that was 3,675 Mg C ha-1. Logging and draining had reduced the biomass of trees and the peat carbon pools. My study demonstrated that tropical coastal PSF has the largest total carbon stocks among terrestrial ecosystems on earth. The large carbon stocks and high rates of PSF degradation, points to the relevance for inclusion of PSF in nationally appropriate climate change mitigation and adaptation strategies. The mean ecosystem carbon stock for the PSF sites was 4,401 Mg C ha-1. Ecosystem C stocks of LPSF, ES and OP was 3,768, 3,147, and 3,442 Mg C ha-1, respectively. PSF stocks was significantly higher than the degraded land covers. At all sites, soils comprised > 96% of the mean ecosystem carbon stock. Using the estimation based on ecosystem carbon loss to total peat depths, the conversion of PSF to LPSF, ES and OP was estimated to result in a net loss of 1,982, 4,259 and 3,176 Mg C-CO2 ha-1, respectively. My results confirm that land cover change significantly impacted soil properties and reduced ecosystem carbon stocks. The tropical peatlands need urgent and significant efforts in conservation and restoration, to regain its function as a C sink and mitigate climate change. I found that land use/land cover change resulted in large shifts in NPP and NEP. LPSF, ES and OP have significantly lower NPP (11.1 Mg C ha-1 yr-1, 10.8 Mg C ha-1 yr-1 and 3.7 Mg C ha-1 yr-1, respectively) than PSF (13.2 Mg C ha-1 yr-1). ES showed lower heterotrophic respiration (30.7 Mg CO2 ha-1 yr-1) than PSF, LPSF and OP (37.7 Mg CO2 ha-1 yr-1, 40.7 Mg CO2 ha-1 yr-1, 38.7 Mg CO2 ha-1 yr-1, respectively). LPSF and OP were net carbon sources; they have negative mean NEP values (-0.1 Mg CO2-e ha-1 yr-1 and -25.1 Mg CO2-e ha-1 yr-1, respectively). In contrast PSF and ES were net carbon sinks (10.8 Mg CO2-e ha-1 yr-1 and 9.1 CCO2 ha-1 yr-1, respectively). PSF is among the most productive of terrestrial ecosystems, with an NPP exceeding that of many tropical rain forests and similar to the most productive mangrove ecosystems. I found that land use decreases productivity of the LPSF and OP sites. The ES had a similar NEP to the PSF, but frequent fires in this ecosystem likely offset carbon gains during the fire intervals. Land use change and forest degradation have shifted tropical PSFs from net carbon sinks to net carbon sources. My study demonstrated that land conversion in tropical peat swamp forests should be halted and degraded peatlands need to be restored in order to mitigate climate change. Close

• 445. [Article] Converting forest biomass to energy in Oregon : stakeholder perspectives on a growing movement

  Within Oregon there is considerable interest in the possibility of converting woody biomass to energy. This interest stems from three converging factors: the desire to reduce the threat of uncharacteristic ...

  Citation × Citation Citation Abstract Copy Title: Converting forest biomass to energy in Oregon : stakeholder perspectives on a growing movement Author: Stidham, Melanie Within Oregon there is considerable interest in the possibility of converting woody biomass to energy. This interest stems from three converging factors: the desire to reduce the threat of uncharacteristic wildfire by removing excess material from the forests, the possibility to stimulate rural economies that are dependent on forest products, and generation of renewable and/or clean energy from a local source. There have been a number of studies to assess the feasibility of wide-scale conversion of biomass to energy. These efforts have largely focused on technical barriers to the use of biomass for energy rather than social barriers. This study explores the social context of converting forest biomass to energy, through use of semi-structured interviews. Forty interviewees were purposively selected from the following Oregon stakeholder groups: federal and state agencies, elected officials, community organizations, conservation organizations, the forest industry sector, Tribes, energy utilities and non-utility energy experts. Information gained through the interviews was used to meet two research objectives: 1) to understand stakeholders' views on converting forest biomass to energy in Oregon; 2) to identify, from the perspectives of stakeholders, the opportunities for and barriers to converting forest biomass to energy, and potential strategies to overcome the barriers. In addition, there were two secondary objectives: a) to identify areas of common ground and conflict between and within stakeholder groups; and b) to identify policy components that would be necessary in the integration of the forestry and energy industries in Oregon. Among research participants there was wide agreement on what constitutes forest biomass; typically small diameter material that is currently non-merchantable, produced as a by-product of restoration or other forest management activities. There was most agreement that restoration treatments are needed in low-elevation ponderosa pine forests in eastern and southwestern Oregon to reduce the risk of uncharacteristically large and severe wildfire. It is this risk of unusually intense wildfire that many research participants felt was driving this issue in Oregon, rather than potential energy or rural economic development benefits. Many research participants wanted at-risk forests restored to conditions within their historic/natural range of variability, which depended on site specific characteristics, but generally meant fewer trees per acre and inclusion of low-intensity fire. The top three reasons research participants were interested in biomass utilization were the opportunities to generate renewable energy, restore forests, and stimulate economic growth in rural communities. While participants were enthusiastic about these opportunities, they brought up a number of barriers that would have to be addressed before the full suite of opportunities could be realized. The most vital and most challenging barrier was access to supply. Factors making supply more difficult to secure included the expense associated with long transport distances, and that while supply needs to be long-term, continuous, inexpensive, and guaranteed, it is mostly on federal land, where the public is involved in land management decisions and politics plays a role. Another challenge is the long history of contention between parties related to forest products coming from federal land, and these parties would have to all agree that biomass utilization using supply from federal forests is acceptable before supply could be made available. Many research participants suggested that collaboration could allow these projects to be developed in a manner acceptable to all parties. Costs could be federally subsidized to make projects more feasible. Participants encouraged development of pilot projects to move discussion from speculation to actuality. Many research participants expressed more comfort in smaller energy facilities to prevent energy needs from dictating forest management, i.e., to prevent the tail from wagging the dog. The overarching goal of this research is to provide information useful to collaboration groups, policymakers, land managers, communities, and relevant advocacy groups to create a foundation for discussions as forest biomass energy becomes an increasingly prominent issue in Oregon. Title: Converting forest biomass to energy in Oregon : stakeholder perspectives on a growing movement Author: Stidham, Melanie Within Oregon there is considerable interest in the possibility of converting woody biomass to energy. This interest stems from three converging factors: the desire to reduce the threat of uncharacteristic wildfire by removing excess material from the forests, the possibility to stimulate rural economies that are dependent on forest products, and generation of renewable and/or clean energy from a local source. There have been a number of studies to assess the feasibility of wide-scale conversion of biomass to energy. These efforts have largely focused on technical barriers to the use of biomass for energy rather than social barriers. This study explores the social context of converting forest biomass to energy, through use of semi-structured interviews. Forty interviewees were purposively selected from the following Oregon stakeholder groups: federal and state agencies, elected officials, community organizations, conservation organizations, the forest industry sector, Tribes, energy utilities and non-utility energy experts. Information gained through the interviews was used to meet two research objectives: 1) to understand stakeholders' views on converting forest biomass to energy in Oregon; 2) to identify, from the perspectives of stakeholders, the opportunities for and barriers to converting forest biomass to energy, and potential strategies to overcome the barriers. In addition, there were two secondary objectives: a) to identify areas of common ground and conflict between and within stakeholder groups; and b) to identify policy components that would be necessary in the integration of the forestry and energy industries in Oregon. Among research participants there was wide agreement on what constitutes forest biomass; typically small diameter material that is currently non-merchantable, produced as a by-product of restoration or other forest management activities. There was most agreement that restoration treatments are needed in low-elevation ponderosa pine forests in eastern and southwestern Oregon to reduce the risk of uncharacteristically large and severe wildfire. It is this risk of unusually intense wildfire that many research participants felt was driving this issue in Oregon, rather than potential energy or rural economic development benefits. Many research participants wanted at-risk forests restored to conditions within their historic/natural range of variability, which depended on site specific characteristics, but generally meant fewer trees per acre and inclusion of low-intensity fire. The top three reasons research participants were interested in biomass utilization were the opportunities to generate renewable energy, restore forests, and stimulate economic growth in rural communities. While participants were enthusiastic about these opportunities, they brought up a number of barriers that would have to be addressed before the full suite of opportunities could be realized. The most vital and most challenging barrier was access to supply. Factors making supply more difficult to secure included the expense associated with long transport distances, and that while supply needs to be long-term, continuous, inexpensive, and guaranteed, it is mostly on federal land, where the public is involved in land management decisions and politics plays a role. Another challenge is the long history of contention between parties related to forest products coming from federal land, and these parties would have to all agree that biomass utilization using supply from federal forests is acceptable before supply could be made available. Many research participants suggested that collaboration could allow these projects to be developed in a manner acceptable to all parties. Costs could be federally subsidized to make projects more feasible. Participants encouraged development of pilot projects to move discussion from speculation to actuality. Many research participants expressed more comfort in smaller energy facilities to prevent energy needs from dictating forest management, i.e., to prevent the tail from wagging the dog. The overarching goal of this research is to provide information useful to collaboration groups, policymakers, land managers, communities, and relevant advocacy groups to create a foundation for discussions as forest biomass energy becomes an increasingly prominent issue in Oregon. Close

• 446. [Article] Downstream rearing of juvenile Chinook salmon abundance, distribution and growth in the Upper Mainstem of the John Day River

  Abstract -- Juvenile spring Chinook (Oncorhynchus tshawytscha) emerge from the gravel in the late winter or early spring, and most follow a life history pattern known as Natal Reach Rearing (NRR) in which ...

  Citation × Citation Citation Abstract Copy Title: Downstream rearing of juvenile Chinook salmon abundance, distribution and growth in the Upper Mainstem of the John Day River Abstract -- Juvenile spring Chinook (Oncorhynchus tshawytscha) emerge from the gravel in the late winter or early spring, and most follow a life history pattern known as Natal Reach Rearing (NRR) in which juvenile fish remain in the stream reaches where they were spawned until their second spring of life when they start migrating towards the ocean (Healey 1991). However, in Columbia River tributaries, some juveniles have been observed following a Downstream Rearing (DSR) life history, in which they start moving downstream during their first spring towards other nursery habitats or perhaps ocean rearing (Copeland & Venditti 2009; Schroeder et al. 2016). Rearing in different habitats during their first year gives fish with these two life histories access to diverse food resources and, it is hypothesized that, this leads to different survival and growth advantages for these two groups. Differences in growth are of interest in efforts to conserve this threatened species because size is positively correlated to survival for salmon across multiple stages of their life cycle (Groot & Margolis 1991; Healey 1991; Quinn & Peterson 1996; Roni et al. 2012) Chinook salmon in the upper John Day River, Oregon, exhibit both NRR and DSR life history patterns. Fish following the DSR life history pattern are larger than NRR fish late in the spring, possibly due to factors such as higher fish density, lower stream productivity, and colder water temperatures in their natal reach than in the downstream reaches. However, this size advantage may be lost due to adverse summer conditions. Hot summer days combined with the withdrawal of water for agriculture lead to stream water temperatures well above lethal thresholds for salmon in many downstream reaches. DSR fish have been observed in tributaries of the mainstem John Day River, however their growth and survival during summer is unknown. Title: Downstream rearing of juvenile Chinook salmon abundance, distribution and growth in the Upper Mainstem of the John Day River Abstract -- Juvenile spring Chinook (Oncorhynchus tshawytscha) emerge from the gravel in the late winter or early spring, and most follow a life history pattern known as Natal Reach Rearing (NRR) in which juvenile fish remain in the stream reaches where they were spawned until their second spring of life when they start migrating towards the ocean (Healey 1991). However, in Columbia River tributaries, some juveniles have been observed following a Downstream Rearing (DSR) life history, in which they start moving downstream during their first spring towards other nursery habitats or perhaps ocean rearing (Copeland & Venditti 2009; Schroeder et al. 2016). Rearing in different habitats during their first year gives fish with these two life histories access to diverse food resources and, it is hypothesized that, this leads to different survival and growth advantages for these two groups. Differences in growth are of interest in efforts to conserve this threatened species because size is positively correlated to survival for salmon across multiple stages of their life cycle (Groot & Margolis 1991; Healey 1991; Quinn & Peterson 1996; Roni et al. 2012) Chinook salmon in the upper John Day River, Oregon, exhibit both NRR and DSR life history patterns. Fish following the DSR life history pattern are larger than NRR fish late in the spring, possibly due to factors such as higher fish density, lower stream productivity, and colder water temperatures in their natal reach than in the downstream reaches. However, this size advantage may be lost due to adverse summer conditions. Hot summer days combined with the withdrawal of water for agriculture lead to stream water temperatures well above lethal thresholds for salmon in many downstream reaches. DSR fish have been observed in tributaries of the mainstem John Day River, however their growth and survival during summer is unknown. Close

• 447. [Article] Direct and indirect effects of livestock grazing intensity on processes regulating grassland bird populations

  In grasslands, grazing by large ungulates can influence vegetation structure, composition, primary productivity, and ultimately, ecosystem functioning. While grazing represents a complex disturbance, grazing ...

  Citation × Citation Citation Abstract Copy Title: Direct and indirect effects of livestock grazing intensity on processes regulating grassland bird populations Author: Johnson, Tracey N. In grasslands, grazing by large ungulates can influence vegetation structure, composition, primary productivity, and ultimately, ecosystem functioning. While grazing represents a complex disturbance, grazing intensity largely determines the effects of grazing on vegetation. Structural and compositional changes in the plant community caused by grazing could have bottom-up effects on species and interactions at higher trophic levels. Thus, particular management strategies for domestic livestock in rangeland systems could exert a strong affect on grassland wildlife. Grassland-dependent songbirds may be particularly susceptible to the effects of domestic grazers because they depend on grassland vegetation for foraging and nesting. Domestic livestock may influence grassland-breeding bird populations by affecting settlement decisions, resource availability, or reproductive success. We investigated the effects of grazing intensity on grassland vegetation structure and songbird demography in a northwestern bunchgrass prairie using paddocks with experimentally-manipulated cattle stocking rates. We compared effects of four stocking rates (0, 14.4, 28.8, and 43.2 animal unit months) on songbirds using a randomized complete block design with four replicates of each stocking rate to address hypotheses regarding demography of grassland songbirds. Overall paddock-level vegetation structure decreased and structural heterogeneity of vegetation increased with higher stocking rates, and those effects carried over one-year post-grazing. However, most bird species were able to locate nesting sites with similar vegetation structure regardless of paddock-level effects of stocking rate. The exceptions were western meadowlarks and vesper sparrows; nests of these species in paddocks with higher stocking rates had less vegetative cover. Apparent nest density for grasshopper sparrows was negatively affected by higher stocking rates. Grazing treatment effects on songbird population density were restricted to negative effects of higher stocking rates on savannah sparrows, but this relationship was not observed until the post-treatment year. Songbird community composition differed between control and heavily-grazed paddocks, but diversity was not affected by stocking rate. Nest fates were evaluated to determine whether stocking rate influenced nest survival or cause-specific nest failure. Other variables such as vegetation structure and predator community, date, year, and nest age were included to help clarify which mechanisms might be responsible for differences in nest survival or failure rates among treatments. For our analysis, we introduce the use of a novel software package, McNestimate, to estimate the daily probability of nest survival and failure from specific causes. McNestimate estimates the probability of nest failure from competing causes when the exact dates of failure are unknown using a Markov Chain framework, and incorporates a model selection approach which allows the use of covariates to help identify variables important in explaining variation in the daily probability of nest failure. Nest predation rates increased with the age of the nest and throughout the breeding season, but were not affected by stocking rate. The probability of nest failure from adverse weather declined throughout the season, but the rate of decline depended on year. Nest failure rates due to trampling were higher in paddocks with higher stocking rates, but also depended on the number of days cattle were present during the nesting period. Patterns of overall probability of nest success were driven by predation patterns in the first year, but in the second year were strongly influenced by the chances of weather-related nest failure. Although starvation was not identified as a significant source of nest failure, grazing-induced changes to vegetation structure and composition could influence food availability for breeding songbirds, ultimately affecting the composition of nestling diets and nestling condition. To better understand the relationship between grazing intensity, nestling diet composition, and subsequent effects on nestling condition, we examined the invertebrate composition of nestling fecal samples. All species showed strong preferences for Lepidoptera (moths and butterflies) larvae, and partial preferences for Coleoptera (beetles) and Araneae (spiders). The proportion of preferred prey items was not affected by stocking rate. There were effects of bird species on the proportion of Araneae and Coleoptera and the proportion of Acrididae (short-horned grasshoppers) in the diet of western meadowlark nestlings decreased with high stocking rates. Growth rates for western meadowlarks and vesper sparrows were negatively affected by higher stocking rates. These results suggest that stocking rates can have variable effects on grassland songbird population and nest density depending on each species' habitat requirements. However, negative effects of high stocking rates on nest survival and nestling condition could have consequences for juvenile survival and recruitment. Overall, low-to-moderate stocking rates are likely compatible with many grassland bird species in northwest bunchgrass prairie, and although heavier livestock grazing may help create suitable vegetation structure for some songbird species, high stocking rates may influence grassland songbird diet quality, or have negative effects on nestling condition. We hypothesized that grazing intensity could influence the grassland songbird community through "bottom-up" effects on vegetation, but effects of grazing at different intensities did not translate directly through the food web to influence songbird populations as strongly as lower trophic levels. Processes responsible for changes in community composition such as immigration or emigration may not have had time to ensue during our short-term experiment; alternatively, sufficient spatial or temporal heterogeneity remained in the system, even at the highest grazing intensity, such that grazing-induced changes in lower trophic levels were irrelevant for most songbird species. Our results contribute to understanding grassland songbird demographic responses to different grazing intensities and identify specific mechanisms by which conservation measures for declining grassland bird populations can be improved. Title: Direct and indirect effects of livestock grazing intensity on processes regulating grassland bird populations Author: Johnson, Tracey N. In grasslands, grazing by large ungulates can influence vegetation structure, composition, primary productivity, and ultimately, ecosystem functioning. While grazing represents a complex disturbance, grazing intensity largely determines the effects of grazing on vegetation. Structural and compositional changes in the plant community caused by grazing could have bottom-up effects on species and interactions at higher trophic levels. Thus, particular management strategies for domestic livestock in rangeland systems could exert a strong affect on grassland wildlife. Grassland-dependent songbirds may be particularly susceptible to the effects of domestic grazers because they depend on grassland vegetation for foraging and nesting. Domestic livestock may influence grassland-breeding bird populations by affecting settlement decisions, resource availability, or reproductive success. We investigated the effects of grazing intensity on grassland vegetation structure and songbird demography in a northwestern bunchgrass prairie using paddocks with experimentally-manipulated cattle stocking rates. We compared effects of four stocking rates (0, 14.4, 28.8, and 43.2 animal unit months) on songbirds using a randomized complete block design with four replicates of each stocking rate to address hypotheses regarding demography of grassland songbirds. Overall paddock-level vegetation structure decreased and structural heterogeneity of vegetation increased with higher stocking rates, and those effects carried over one-year post-grazing. However, most bird species were able to locate nesting sites with similar vegetation structure regardless of paddock-level effects of stocking rate. The exceptions were western meadowlarks and vesper sparrows; nests of these species in paddocks with higher stocking rates had less vegetative cover. Apparent nest density for grasshopper sparrows was negatively affected by higher stocking rates. Grazing treatment effects on songbird population density were restricted to negative effects of higher stocking rates on savannah sparrows, but this relationship was not observed until the post-treatment year. Songbird community composition differed between control and heavily-grazed paddocks, but diversity was not affected by stocking rate. Nest fates were evaluated to determine whether stocking rate influenced nest survival or cause-specific nest failure. Other variables such as vegetation structure and predator community, date, year, and nest age were included to help clarify which mechanisms might be responsible for differences in nest survival or failure rates among treatments. For our analysis, we introduce the use of a novel software package, McNestimate, to estimate the daily probability of nest survival and failure from specific causes. McNestimate estimates the probability of nest failure from competing causes when the exact dates of failure are unknown using a Markov Chain framework, and incorporates a model selection approach which allows the use of covariates to help identify variables important in explaining variation in the daily probability of nest failure. Nest predation rates increased with the age of the nest and throughout the breeding season, but were not affected by stocking rate. The probability of nest failure from adverse weather declined throughout the season, but the rate of decline depended on year. Nest failure rates due to trampling were higher in paddocks with higher stocking rates, but also depended on the number of days cattle were present during the nesting period. Patterns of overall probability of nest success were driven by predation patterns in the first year, but in the second year were strongly influenced by the chances of weather-related nest failure. Although starvation was not identified as a significant source of nest failure, grazing-induced changes to vegetation structure and composition could influence food availability for breeding songbirds, ultimately affecting the composition of nestling diets and nestling condition. To better understand the relationship between grazing intensity, nestling diet composition, and subsequent effects on nestling condition, we examined the invertebrate composition of nestling fecal samples. All species showed strong preferences for Lepidoptera (moths and butterflies) larvae, and partial preferences for Coleoptera (beetles) and Araneae (spiders). The proportion of preferred prey items was not affected by stocking rate. There were effects of bird species on the proportion of Araneae and Coleoptera and the proportion of Acrididae (short-horned grasshoppers) in the diet of western meadowlark nestlings decreased with high stocking rates. Growth rates for western meadowlarks and vesper sparrows were negatively affected by higher stocking rates. These results suggest that stocking rates can have variable effects on grassland songbird population and nest density depending on each species' habitat requirements. However, negative effects of high stocking rates on nest survival and nestling condition could have consequences for juvenile survival and recruitment. Overall, low-to-moderate stocking rates are likely compatible with many grassland bird species in northwest bunchgrass prairie, and although heavier livestock grazing may help create suitable vegetation structure for some songbird species, high stocking rates may influence grassland songbird diet quality, or have negative effects on nestling condition. We hypothesized that grazing intensity could influence the grassland songbird community through "bottom-up" effects on vegetation, but effects of grazing at different intensities did not translate directly through the food web to influence songbird populations as strongly as lower trophic levels. Processes responsible for changes in community composition such as immigration or emigration may not have had time to ensue during our short-term experiment; alternatively, sufficient spatial or temporal heterogeneity remained in the system, even at the highest grazing intensity, such that grazing-induced changes in lower trophic levels were irrelevant for most songbird species. Our results contribute to understanding grassland songbird demographic responses to different grazing intensities and identify specific mechanisms by which conservation measures for declining grassland bird populations can be improved. Close

• 448. [Article] Water and Soil Management Practices to Enhance Plant Growth, Berry Development, and Fruit Quality of Northern Highbush Blueberry (Vaccinium corymbosum L.)

  Drought and mandatory water restrictions are limiting the availability of irrigation water in many important blueberry growing regions and new strategies are needed to maintain yield and fruit quality ...

  Citation × Citation Citation Abstract Copy Title: Water and Soil Management Practices to Enhance Plant Growth, Berry Development, and Fruit Quality of Northern Highbush Blueberry (Vaccinium corymbosum L.) Author: Almutairi, Khalid F. Drought and mandatory water restrictions are limiting the availability of irrigation water in many important blueberry growing regions and new strategies are needed to maintain yield and fruit quality with less water. Three potential options for reducing water use, including deficit irrigation, irrigation cut-offs, and crop thinning, were evaluated for 2 years in a mature planting of northern highbush blueberry (Vaccinium corymbosum L. ‘Elliott’). Treatments consisted of no thinning and 50% crop removal in combination with either full irrigation at 100% of estimated crop evapotranspiration (ETsubscript c]), deficit irrigation at 50% ET[subscript c] (applied for the entire growing season), or full irrigation with irrigation cut-off for 4–6 weeks during early or late stages of fruit development. Stem water potential was similar with full and deficit irrigation but, regardless of crop thinning, declined by 0.5–0.6 MPa when irrigation was cut-off early and by > 2.0 MPa when irrigation was cut-off late. In one or both years, the fruiting season was advanced with either deficit irrigation or late cut-off, whereas cutting off irrigation early delayed the season. Yield was not affected by deficit irrigation in plants with a full crop load but was reduced by an average of 35% when irrigation was cut-off late each year. Cutting off irrigation early likewise reduced yield, but only in the second year when the plants were not thinned; however, early cut-off also reduced fruit soluble solids and berry weight by 7% to 24%compared to full irrigation. Cutting off irrigation late produced the smallest and firmest fruit with the highest soluble solids and total acidity among the treatments, as well as the slowest rate of fruit loss in cold storage. Deficit irrigation had the least effect on fruit quality and, based on these results, appears to be the most viable option for maintaining yield with less water (2.5 ML·ha⁻¹ less water per season). A second study was conducted in a 7-year-old field of certified organic highbush blueberry. Two cultivars (‘Duke’ and ‘Liberty’) mulched with either porous polyethylene ground cover (“weed mat”) or yard debris compost topped with sawdust (sawdust+compost) and each fertilized with either feather meal or fish emulsion were evaluated. One-year-old fruiting laterals were randomly-selected at three heights (top, middle, and bottom) on the east and west side of the plants. Bud, flower, and fruit development were monitored through fruit harvest. There was relatively little effect of mulch type or fertilizer source on the measured variables. Fruit harvest occurred ≈8 d after the fruit were fully blue and ranged from 2-25 July 2012 and 26 June-3 July 2013 in ‘Duke’ and from 1-20 Aug. 2012 and 17 July-7 Aug. 2013 in ‘Liberty’. Proportionally more fruit buds occurred on middle laterals than upper and lower laterals. The dates of bud swell and bud break were not affected by cultivar or lateral position. ‘Duke’ and ‘Liberty’ produced 6-8 and 7-9 flowers/bud, respectively. Fruit set was high in both cultivars, averaging ≈95%. However, 13-18% and 29-38 % of the initial set fruit dropped in ’Duke’ and ‘Liberty’ in late May to early June. Fruit ripening was more uniform within clusters in ‘Duke’ than in ‘Liberty’, and average fruit size was similar among harvests in ‘Duke’ but decreased by 25-40% between the first and last harvest in ‘Liberty’. Fruit matured 3−5 d earlier on the east side of the canopy than on the west side. The results suggest that pruning proportionally more on the lower part of the canopy than on the upper part will result in larger fruit at harvest than uniform pruning throughout the bush. The final study was conducted to determine the potential of applying micronized elemental sulfur (S°) by chemigation through the drip system to reduce high soil pH in a new planting of ‘Duke’ blueberry. The S° was mixed with water and injected weekly for 2 months prior to planting, as well as 2 years after planting, atrates of 0, 50, 100 and 150 kg·ha⁻¹ per year, and was compared to the conventional practice of incorporating prilled S° into the soil prior to planting (two applications of 750 kg·ha⁻¹ each). Chemigation quickly reduced soil pH (0-10 cm) within a month from 6.6 with no S° to 6.1 with 50 kg·ha-1 S° and 5.8 with 100 or 150 kg·ha⁻¹ S°. The change was short-term, however, and by May of the following year, soil pH averaged 6.7, 6.5, 6.2, and 6.1 with each increasing rate of S° chemigation, respectively. The conventional treatment, in comparison, averaged 6.6 on the first date and 6.3 on the second date. In July of the following year, soil pH ranged from an average of 6.4 with no S° to 6.2 with 150 kg·ha⁻¹ S° and 5.5 with prilled S°. Soil pH declined thereafter to as low as 5.9 with additional S° chemigation and at lower depths (10-30 cm) was similar to the conventional treatment. None of the treatments had any effect on winter pruning weight in year 1 or on yield, berry weight, and plant dry weight in year 2. Chemigation with S° can be used to quickly reduce soil pH following planting and, therefore, may be a useful practice to correct high pH problems in established blueberry fields. However, it was less effective and more time consuming than applying prilled S° prior to planting. Title: Water and Soil Management Practices to Enhance Plant Growth, Berry Development, and Fruit Quality of Northern Highbush Blueberry (Vaccinium corymbosum L.) Author: Almutairi, Khalid F. Drought and mandatory water restrictions are limiting the availability of irrigation water in many important blueberry growing regions and new strategies are needed to maintain yield and fruit quality with less water. Three potential options for reducing water use, including deficit irrigation, irrigation cut-offs, and crop thinning, were evaluated for 2 years in a mature planting of northern highbush blueberry (Vaccinium corymbosum L. ‘Elliott’). Treatments consisted of no thinning and 50% crop removal in combination with either full irrigation at 100% of estimated crop evapotranspiration (ETsubscript c]), deficit irrigation at 50% ET[subscript c] (applied for the entire growing season), or full irrigation with irrigation cut-off for 4–6 weeks during early or late stages of fruit development. Stem water potential was similar with full and deficit irrigation but, regardless of crop thinning, declined by 0.5–0.6 MPa when irrigation was cut-off early and by > 2.0 MPa when irrigation was cut-off late. In one or both years, the fruiting season was advanced with either deficit irrigation or late cut-off, whereas cutting off irrigation early delayed the season. Yield was not affected by deficit irrigation in plants with a full crop load but was reduced by an average of 35% when irrigation was cut-off late each year. Cutting off irrigation early likewise reduced yield, but only in the second year when the plants were not thinned; however, early cut-off also reduced fruit soluble solids and berry weight by 7% to 24%compared to full irrigation. Cutting off irrigation late produced the smallest and firmest fruit with the highest soluble solids and total acidity among the treatments, as well as the slowest rate of fruit loss in cold storage. Deficit irrigation had the least effect on fruit quality and, based on these results, appears to be the most viable option for maintaining yield with less water (2.5 ML·ha⁻¹ less water per season). A second study was conducted in a 7-year-old field of certified organic highbush blueberry. Two cultivars (‘Duke’ and ‘Liberty’) mulched with either porous polyethylene ground cover (“weed mat”) or yard debris compost topped with sawdust (sawdust+compost) and each fertilized with either feather meal or fish emulsion were evaluated. One-year-old fruiting laterals were randomly-selected at three heights (top, middle, and bottom) on the east and west side of the plants. Bud, flower, and fruit development were monitored through fruit harvest. There was relatively little effect of mulch type or fertilizer source on the measured variables. Fruit harvest occurred ≈8 d after the fruit were fully blue and ranged from 2-25 July 2012 and 26 June-3 July 2013 in ‘Duke’ and from 1-20 Aug. 2012 and 17 July-7 Aug. 2013 in ‘Liberty’. Proportionally more fruit buds occurred on middle laterals than upper and lower laterals. The dates of bud swell and bud break were not affected by cultivar or lateral position. ‘Duke’ and ‘Liberty’ produced 6-8 and 7-9 flowers/bud, respectively. Fruit set was high in both cultivars, averaging ≈95%. However, 13-18% and 29-38 % of the initial set fruit dropped in ’Duke’ and ‘Liberty’ in late May to early June. Fruit ripening was more uniform within clusters in ‘Duke’ than in ‘Liberty’, and average fruit size was similar among harvests in ‘Duke’ but decreased by 25-40% between the first and last harvest in ‘Liberty’. Fruit matured 3−5 d earlier on the east side of the canopy than on the west side. The results suggest that pruning proportionally more on the lower part of the canopy than on the upper part will result in larger fruit at harvest than uniform pruning throughout the bush. The final study was conducted to determine the potential of applying micronized elemental sulfur (S°) by chemigation through the drip system to reduce high soil pH in a new planting of ‘Duke’ blueberry. The S° was mixed with water and injected weekly for 2 months prior to planting, as well as 2 years after planting, atrates of 0, 50, 100 and 150 kg·ha⁻¹ per year, and was compared to the conventional practice of incorporating prilled S° into the soil prior to planting (two applications of 750 kg·ha⁻¹ each). Chemigation quickly reduced soil pH (0-10 cm) within a month from 6.6 with no S° to 6.1 with 50 kg·ha-1 S° and 5.8 with 100 or 150 kg·ha⁻¹ S°. The change was short-term, however, and by May of the following year, soil pH averaged 6.7, 6.5, 6.2, and 6.1 with each increasing rate of S° chemigation, respectively. The conventional treatment, in comparison, averaged 6.6 on the first date and 6.3 on the second date. In July of the following year, soil pH ranged from an average of 6.4 with no S° to 6.2 with 150 kg·ha⁻¹ S° and 5.5 with prilled S°. Soil pH declined thereafter to as low as 5.9 with additional S° chemigation and at lower depths (10-30 cm) was similar to the conventional treatment. None of the treatments had any effect on winter pruning weight in year 1 or on yield, berry weight, and plant dry weight in year 2. Chemigation with S° can be used to quickly reduce soil pH following planting and, therefore, may be a useful practice to correct high pH problems in established blueberry fields. However, it was less effective and more time consuming than applying prilled S° prior to planting. Close

• 449. [Article] Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1992

  Evaluation of previously established field trials of remedial internal treatments demonstrates the continued performance of chioropicrin, Vorlex, and methylisothiocyanate (MITC). While the degree of protection ...

  Citation × Citation Citation Abstract Copy Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1992 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) Evaluation of previously established field trials of remedial internal treatments demonstrates the continued performance of chioropicrin, Vorlex, and methylisothiocyanate (MITC). While the degree of protection afforded by these treatments has declined with time, residual fungitoxic levels remain in many tests. Field trials of gelatin encapsulated MITC indicate that gelatin had no negative effect on fumigant performance even when no water was added at the time of treatment. Closed tube bioassays, chemical analyses, and culturing of Douglas-fir and southern pine poles treated with glass encapsulated METC (MITC-Fume) indicate that this chemical is outperforming metham sodium 3 years after application. While the glass vials lost chemical very slowly, the slow release rate did not appear to adversely affect MITC performance. Trials to evaluate the performance of fused borate rods were sampled after 1 or 2 years of exposure. Chemical analysis of cores removed from the test poles revealed that none of the treatments contained boron at levels which would be considered adequate for arresting or preventing colonization by wood decay fungi. Interestingly, boron levels in poles exposed in Hilo, Hawaii were highest above the treatment hole, suggesting that some upward diffusion of this chemical is possible. The low boron levels in these poles are reason for concern, since a number of utilities are considering the using this formulation for remedial treatment at the groundline. Evaluations of new solid fumigants are progressing. Trials with Basamid indicate that the addition of copper compounds improved the rate of decomposition to produce MITC. Simultaneous addition of copper sulfate and Basamid may be useful for accelerating the decomposition of this compound, making it practical for control of internal decay fungi. Trials have been established to evaluate the performance of gelled and pelletized metham sodium and a sodium fluoride/boron rod. These trials will be evaluated in future reports. A third field trial to evaluate the performance of a copper naphthenate/boron paste for internal treatment of Douglas-fir poles is currently be evaluated to determine chemical levels 3 years after treatment. The performance of gelled metham sodium was further evaluated under laboratory conditions to better understand the performance of this chemical. Gelled metham sodium provided improved fungal control in comparison with liquid metham sodium and appeared to produce increased MITC levels under a variety of test conditions. The improved performance of this formulation may reflect the ability of the gell to retain moisture for longer periods of time than the liquid metham sodium formulation. Further studies of this formulation are underway. Laboratory studies were also performed to evaluate the effects of various additives on the performance of Basamid. Once again, the addition of copper compounds enhanced the production of MITC. A number of other compounds shifted decomposition to the production of carbon disulfide and carbonyl sulfide, two less fungitoxic compounds. Further studies are underway to identify non-sulfur products which may provide some protection against wood decay fungi. Evaluations of the effects of artificial voids on performance of fumigants in Douglas-fir poles indicate that voids had little or no effect on fumigant distribution. As a result, fumigant treatment of solid wood around voids represents a viable strategy for improving pole service life. Evaluation of timbers treated with metham sodium indicate that detectable levels of MITC were present one year after treatment. These timbers will be evaluated in subsequent years to determine the protective period provided by fumigants in sawn material. We continue development of a fumigant movement model using data previously developed on MITC. This year, we evaluated a previously developed system, ANSYS. Results of preliminary trials are similar to data previously developed on MITC-Fume treated poles and indicate that modeling MITC movement should be possible. Further trials are underway to confirm and expand this model. The effect of wood moisture content, temperature and wood species on metham sodium decomposition was investigated under laboratory conditions. The efficiency of dcomposition to MITC varied widely, but was most affected by temperature and wood moisture content. The results suggests that there is considerable potential for improving decomposition efficiency to enhance performance of this fumigant. Further studies to characterize the relationship between chemical content of the wood species and decomposition are underway. Field trials to identify safer treatments for preventing decay of cedar sapwood and protecting field drilled bolt holes are continuing. Diffusible treatments continue to provide excellent protection for field drilled bolt holes. A study to develop estimates of the extent of decay above the groundline in Douglas-fir poles in the Pacific Northwest is underway. The data from this study will be used to develop estimates of the potential for damage and provide some insight into the extent of this problem. Studies to develop guidelines for sterilization of Douglas-fir poles following air-seasoning are continuing. Evaluations of internal temperature development during kiln-drying were completed this year and indicate that internal temperatures during typical pole drying schedules were more than adequate for acheiving sterilization. Further evaluations of the data are underway to develop reliable heating curves for this process. Evaluations of groundline preservative systems have been established at Corvallis, OR and Merced, CA. The results indicate that all of the formulations are moving well through the wood in a manner similar to that found with pentachlorophenol-based systems. Chemical levels in some treatments; however, are beginning to decline 30 months after treatment. Studies are now underway to establish thresholds for combinations of the various formulations. Copper naphthenate treated western redcedar stakelets continue to perform well in fungus cellar trials. Stakes weathered prior to treatment are degrading slightly faster, while freshly sawn stakelets continue to perform well. Field trials have also been established to evaluate the performance of copper naphthenate treated Douglas-fir utility poles in California and Oregon. The chemical levels and fungal colonization will be monitored in these poles to provide a guide to performance of this chemical in western wood species. Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1992 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) Evaluation of previously established field trials of remedial internal treatments demonstrates the continued performance of chioropicrin, Vorlex, and methylisothiocyanate (MITC). While the degree of protection afforded by these treatments has declined with time, residual fungitoxic levels remain in many tests. Field trials of gelatin encapsulated MITC indicate that gelatin had no negative effect on fumigant performance even when no water was added at the time of treatment. Closed tube bioassays, chemical analyses, and culturing of Douglas-fir and southern pine poles treated with glass encapsulated METC (MITC-Fume) indicate that this chemical is outperforming metham sodium 3 years after application. While the glass vials lost chemical very slowly, the slow release rate did not appear to adversely affect MITC performance. Trials to evaluate the performance of fused borate rods were sampled after 1 or 2 years of exposure. Chemical analysis of cores removed from the test poles revealed that none of the treatments contained boron at levels which would be considered adequate for arresting or preventing colonization by wood decay fungi. Interestingly, boron levels in poles exposed in Hilo, Hawaii were highest above the treatment hole, suggesting that some upward diffusion of this chemical is possible. The low boron levels in these poles are reason for concern, since a number of utilities are considering the using this formulation for remedial treatment at the groundline. Evaluations of new solid fumigants are progressing. Trials with Basamid indicate that the addition of copper compounds improved the rate of decomposition to produce MITC. Simultaneous addition of copper sulfate and Basamid may be useful for accelerating the decomposition of this compound, making it practical for control of internal decay fungi. Trials have been established to evaluate the performance of gelled and pelletized metham sodium and a sodium fluoride/boron rod. These trials will be evaluated in future reports. A third field trial to evaluate the performance of a copper naphthenate/boron paste for internal treatment of Douglas-fir poles is currently be evaluated to determine chemical levels 3 years after treatment. The performance of gelled metham sodium was further evaluated under laboratory conditions to better understand the performance of this chemical. Gelled metham sodium provided improved fungal control in comparison with liquid metham sodium and appeared to produce increased MITC levels under a variety of test conditions. The improved performance of this formulation may reflect the ability of the gell to retain moisture for longer periods of time than the liquid metham sodium formulation. Further studies of this formulation are underway. Laboratory studies were also performed to evaluate the effects of various additives on the performance of Basamid. Once again, the addition of copper compounds enhanced the production of MITC. A number of other compounds shifted decomposition to the production of carbon disulfide and carbonyl sulfide, two less fungitoxic compounds. Further studies are underway to identify non-sulfur products which may provide some protection against wood decay fungi. Evaluations of the effects of artificial voids on performance of fumigants in Douglas-fir poles indicate that voids had little or no effect on fumigant distribution. As a result, fumigant treatment of solid wood around voids represents a viable strategy for improving pole service life. Evaluation of timbers treated with metham sodium indicate that detectable levels of MITC were present one year after treatment. These timbers will be evaluated in subsequent years to determine the protective period provided by fumigants in sawn material. We continue development of a fumigant movement model using data previously developed on MITC. This year, we evaluated a previously developed system, ANSYS. Results of preliminary trials are similar to data previously developed on MITC-Fume treated poles and indicate that modeling MITC movement should be possible. Further trials are underway to confirm and expand this model. The effect of wood moisture content, temperature and wood species on metham sodium decomposition was investigated under laboratory conditions. The efficiency of dcomposition to MITC varied widely, but was most affected by temperature and wood moisture content. The results suggests that there is considerable potential for improving decomposition efficiency to enhance performance of this fumigant. Further studies to characterize the relationship between chemical content of the wood species and decomposition are underway. Field trials to identify safer treatments for preventing decay of cedar sapwood and protecting field drilled bolt holes are continuing. Diffusible treatments continue to provide excellent protection for field drilled bolt holes. A study to develop estimates of the extent of decay above the groundline in Douglas-fir poles in the Pacific Northwest is underway. The data from this study will be used to develop estimates of the potential for damage and provide some insight into the extent of this problem. Studies to develop guidelines for sterilization of Douglas-fir poles following air-seasoning are continuing. Evaluations of internal temperature development during kiln-drying were completed this year and indicate that internal temperatures during typical pole drying schedules were more than adequate for acheiving sterilization. Further evaluations of the data are underway to develop reliable heating curves for this process. Evaluations of groundline preservative systems have been established at Corvallis, OR and Merced, CA. The results indicate that all of the formulations are moving well through the wood in a manner similar to that found with pentachlorophenol-based systems. Chemical levels in some treatments; however, are beginning to decline 30 months after treatment. Studies are now underway to establish thresholds for combinations of the various formulations. Copper naphthenate treated western redcedar stakelets continue to perform well in fungus cellar trials. Stakes weathered prior to treatment are degrading slightly faster, while freshly sawn stakelets continue to perform well. Field trials have also been established to evaluate the performance of copper naphthenate treated Douglas-fir utility poles in California and Oregon. The chemical levels and fungal colonization will be monitored in these poles to provide a guide to performance of this chemical in western wood species. Close

• 450. [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