Source: OREGON STATE UNIVERSITY submitted to
WITHIN-TREE VARIATION OF XYLEM ANATOMY: EFFECTS ON TREES AND FOREST PRODUCTS
Sponsoring Institution
Other Cooperating Institutions
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0168729
Grant No.
(N/A)
Project No.
OREZ-FP-614-S
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Apr 3, 1995
Project End Date
Dec 31, 2012
Grant Year
(N/A)
Project Director
Lachenbruch, B.
Recipient Organization
OREGON STATE UNIVERSITY
(N/A)
CORVALLIS,OR 97331
Performing Department
Forest Ecosystems and Society
Non Technical Summary
(N/A)
Animal Health Component
(N/A)
Research Effort Categories
Basic
50%
Applied
50%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
5110612102050%
5110612202050%
Goals / Objectives
1) Study radial and longitudinal variation in wood structure and physiology, andthe environmental factors that alter these. This should improve our understanding of the effects of different silvicultural regimes on wood quality and tree growth. 2) Investigate the effects of growth rate on decay resistance, wood density, and wood structure. 3) Study growth stresses and reaction on wood: the conditions required to cause them and the duration of their formation.
Project Methods
Trees (predominantly Douglas-fir, western redcedar, red alder, and white oak) will be systematically sampled keeping track of radial and longitudinal positions and cambial ages, as well as location with respect to the live crown. Various subsamples will be used for anatomical, densitometric, chemical, mechanical, or dimensional analyses or bioassays (of decay resistance) as appropriate. Studies of reaction wood formation will take advantage of naturally leaning or sinuous individuals, and will also require tree manipulation. Other studies will take advantage of existing plots with pruning trials or other management regimes.

Progress 04/03/95 to 12/31/12

Outputs
OUTPUTS: Over the life of this project, I disseminated information at scientific meetings (about 60 presentations) and to other groups such as stakeholders and fellow scientists and students at the university (about 25 long presentations, numerous shorter ones). I was the Major Professor for 16 graduate students (10 MS and 6 PhD) who I mentored, and I also helped many other students as a graduate committee member for another 68 graduate students. My lab also mentored and advised dozens of undergraduate students, and I mentored three post-doctoral fellows, and three visiting scientists. I was a participant (and co-author) on about 80 peer reviewed publications, five book chapters, and one book. I had an outreach role to many different users. The information and experience I gained was of major importance to all of the outreach and teaching activities in which I participated. I was an annual speaker at our Lumber-Drying Workshop, usually attended by about 35 people from industry, where I spoke for an hour about how wood anatomy ties into wood quality. I participated in Oregon WoodMagic twice a year, our outreach program for 3rd graders, reaching about 1300 students annually since 1999. In that program I explained wood structure and wood use, then had a hands-on demonstration. I taught many different courses, from the very technical (undergraduate wood anatomy to the ones that included social interaction with science, such as Global Issues in Renewable Materials, and Wood, Forests, and Civilization) to both regular students and students in the University Honors College. I became involved in developing and putting on a workshop to help assistant professors advance toward professorship, to help address the problem of many people, especially women, dropping out, thus leading to a decline in diversity in the upper, more powerful levels of the university. As a member of a 6-person team and with a subcontract from NSF, we developed and put on a workshop called Advancing Toward Professorship in the Biological, Ecological, and Earth Systems Sciences (in 2012). This workshop had 32 participants selected from a national pool, had 16 speakers from Oregon and beyond, and informed everyone involved, plus many more people at the open events, about the problems and some solutions for keeping women and others within academics. My experiences gained (described above) were invaluable for this activity. I was the senior member of the team. PARTICIPANTS: There were 16 graduate students who worked on this project, all at Oregon State University in programs leading to the MS degree (10 students) or PhD degree (6) in the Departments of Forest Products, Wood Science and Engineering, and/or Forest Science. One of three post-doctoral fellows was from the University of Utah and the other two were from Oregon State University. Undergraduate students came from Oregon State University, Swarthmore College, and Western Oregon University. High school students came from Corvallis High School. TARGET AUDIENCES: The target audiences included other research scientists, forest managers, wood users, faculty members, and undergraduate and high school students. The research scientists are people who work in the fields of plant ecology, plant physiology, forestry, wood science, and material science. The forest managers include those who are interested in how to manage forests for high wood quality and efficient wood growth, and although the research was mostly confined to the Pacific Northwest, Central America, and Chile, the results are of interest to people in other regions. Likewise, wood users who were in the target audience are those who use these species (mostly from the Pacific Northwest, including Douglas-fir, ponderosa pine, western hemlock, western redcedar, red alder, radiata pine), but because the work is generalizable, it should be of interest to other wood users. These wood users include woodworkers, mills, people of all technical levels involved in lumber drying, and people doing research and development on new wood composites and adhesives. Faculty members served by this work include people who teach wood anatomy, and assistant professors who do field work and who are trying to stay in academics. The undergraduate students include the ones I taught or mentored through research. The Oregon WoodMagic program allowed me to target 3rd-grade children (about 1300/year), their teachers (about 25 per year), and their adult chaperones, usually family members of the students (about 75 per year). About half of the Oregon WoodMagic participants come from low-income school districts. Efforts include formal classroom instruction, laboratory instruction, publications in scholarly journals and books, research experience, and a workshop. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Our research offers an explanation for why trees produced corewood (juvenile wood), which is considered bad for most wood quality applications but that we show is adaptive for tree survival during drought. Upper stems require the ability to bend a long way before they break (their diameter does not impede bending); their wood has high microfibril angle which allows this bending. In contrast, the wood at the bottom of a tree has low microfibril angle which makes the wood stiff. Likewise, upper stems require the ability to transport water at high water tension (high resistance to embolism) because they have little access to stored water and because of the pull of gravity on the long column of water. Indeed, upper stems have much higher resistance to embolism than lower stems. Lower stems, in contrast, require high permeability because water flowing through them needs to go long distances, and indeed, that it what they possess. This information is of importance for tree breeders to maintain the properties of that young wood, and gives insights into design goals for trees of the future that will be faced with climate change. Other research demonstrated that water storage in stems is associated with having wood that is more vulnerable to embolism, which sheds light on wood quality for preservative treatment because wood that is embolized is difficult to treat. We also showed that growth rate does not have a large effect on most wood properties in alder, Douglas-fir and western hemlock; that sinuosity (stem waviness) has very little effect on log quality unless the sinuosity is extreme; and that the foliar pathogen that causes the Swiss Needle Cast disease in Douglas-fir causes wood to become denser and to have higher wood quality. Our research was the first to give empirical supported that tree height is limited by hydraulics and not mechanics. We showed that the pit morphology that was needed to prevent embolism at the top of the tallest trees constrained water transport so much that water was essentially no longer transported above a certain height. We provided information that showed that western redcedar heartwood made from older trees is more decay-resistant than heartwood from younger trees, important because we are increasingly harvesting young trees. We found that the wood quality of ponderosa pine trees grown in the Willamette Valley is as good as or superior to that of ponderosa pine from its more typical habitats. There was a large need for this research because one million ponderosa pine seedlings from the Willamette Valley genotypes were being planted annually but there was no information on what the wood would be like. Hardwoods: We showed that substantial growth stresses can form in alder trees even in the absence of their having specialized cells called tension wood fibers. Growth stresses are beneficial to trees because they help them become upright again if they have become inclined, but they are deleterious to wood quality because they can cause warping and breaking within the wood.

Publications

  • Domec, J.C., B. Lachenbruch, M. Pruyn and R. Spicer. 2012. Age-related increases in sapwood area, leaf area, and xylem conductivity on height-related costs in two coniferous species. Annals of Forest Science 69:17-27.
  • Hacke, U.G., A.L. Jacobsen, R.B. Pratt, C. Maurel and B. Lachenbruch. 2012. New research on plant-water relations examines the molecular, structural, and physiological mechanisms of plant responses to their environment. New Phytologist 196:345-348.
  • Lachenbruch, B. 2012. Ecological wood anatomy: Within-tree variability. pp. 121-122 In: Proceedings, 2012 IUFRO Conference, Division 5, Forest Products.
  • Lens, F.L. Cooper, M.A. Gandolfo, A. Groover, P. Jaiswal, B. Lachenbruch, R. Spicer, M. Staton, D.W. Stevenson, R.L. Walls and J. Wegrzyn. 2012. An extension of the plant ontology project supporting wood anatomy and development research. IAWA J. 33: 113-117.
  • Marias, D.E., F.C. Meinzer, D. Shaw, D.R. Woodruff, S.L. Voelker and B. Lachenbruch. 2012. Effect of hemlock dwarf mistletoe on the physiology of host western hemlock using tee rings and C and O stable isotopes. Ecological Society of America, Portland, OR. http://eco.confex.com/eco/2012/webprogram/Paper36625.html.
  • McCulloh, K.A., D.M. Johnson, F.C. Meinzer, S.L. Voelker, B. Lachenbruch and J.-C. Domec. 2012. Hydraulic architecture of two species differing in wood density: opposing strategies in co-occurring tropical pioneer trees. Plant Cell and Environment 35:116-125.
  • McCulloh, K.A., D.M. Johnson, J.P. Petitmermet, B.E. McNellis, F.C. Meinzer and B. Lachenbruch. 2012. Are shrubs short because of their hydraulic architecture A comparison of co-occurring trees and shrubs. Ecological Society of America, Portland, OR. http://eco.confex.com/eco/2012/webprogram/Paper38837.html. Newton, M., E.C. Cole, B. Lachenbruch and J.M. Robbins. 2012. Branch size and longevity linked to initial plantation spacing and rectangularity in young Douglas-fir. Forest Ecology and Management 266:75-82.
  • Saffell, B.,. F.C. Meinzer, B. Lachenbruch, S. Voelker and D. Shaw. 2012. Use of tree-ring stable isotopes to quantify Swiss Needle Cast disease severity in Douglas-fir. Ecological Society of America, Portland, Oregon. http://eco.confex.com/eco/2012/webprogram/Paper38682.html.
  • Voelker, S.L., F.C. Meinzer, B. Lachenbruch, J.R. Brooks, M.C. Stambaugh and R.P. Guyette. 2012. Colder springs and warmer, wetter summers during the late glacial climate of central North America: Inferences from stable isotopes deltaD and delta13C and wood anatomy of sub-fossil oak wood. Ecological Society of America, Portland, OR. http://eco.confex.com/eco/2012/webprogram/Paper39167.html.
  • Barnard, D.M., F.C. Meinzer, B. Lachenbruch, K.A. McCulloh, D.M. Johnson, and D.R. Woodruff. 2011. Climate-related trends in sapwood biophysical properties in two conifers: Avoidance of hydraulic dysfunction through coordinated adjustments in xylem efficiency, safety and capacitance. Plant Cell and Environment 34:643-644.
  • Boersma, K.S., M.T. Kavanaugh, L.M. Ganio, L.A. Hooven, S.L. Close and B. Lachenbruch. 2012. Advancing toward professorship in biology, ecology, and earth systems sciences: Perceptions of confidence in early career scientists. Ecological Society of America, Portland, Oregon. http://eco.confex.com/eco/2012/webprogram/Paper39715.html.


Progress 01/01/11 to 12/31/11

Outputs
OUTPUTS: Together with colleagues, I shared results in talks and used them in an NSF grant proposal. To help explain wood quality and within-plant variation I built a number of physical models showing wood structure in a way that helps me explain it to audiences. These models are outputs, as is the poster display in my building that describes the models and has examples of student-made models affixed to it. I presented basic wood information to over 2000 3rd and 4th graders and their adult chaperons as part of the Oregon Wood Magic programs in Corvallis (3 days) and Portland (2 days), and spoke about wood quality and anatomy for 40 attendees of a workshop on how to dry wood for quality and profit. Using knowledge from this project, I put together a proposal that provided a Digital Microscope for the College of Forestry, that is now being used widely. PARTICIPANTS: The main participants were OSU undergraduates, graduate students, and postdocs. There were three undergraduates who worked in the lab as hourly workers. We had three graduate students for whom I was major professor, and other grad students used the lab regularly for the equipment. There is much other training that occurred. For example, we have an ongoing weekly lab group meeting for 10 people (two professors, two post-docs, a visiting scientist from Europe, another PhD scientist, and several graduate students and a lab technician). This period leads to other opportunities, such as the post-doc offering to who the grad students how to do a new technique. Everyone is encouraged to attend professional meetings. TARGET AUDIENCES: The target audiences were varied, including the students of OSU (with their ethnic and racial minorities), my graduate students and post-docs, the 3rd and 4th grade children and their parents, the working professionals who attended the workshop in which I was involved (Lumber Drying), and fellow academic and agency scientists. The efforts include formal classroom instruction, practicum experiences, the workshops in which I was an invited speaker, and the Wood Magic program for the gradeschool children. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
A long-standing question in wood quality is why trees produce specific radial patterns in wood properties. I developed numerous hypotheses based on potential hydraulic and mechanical roles of wood when trees are small vs. large, to get at the radial variation. I then eliminated hypotheses that were not consistent with physics and known information about trees, until I had a set of testable hypotheses for why conifers make wood with radial variation. I view this as one of the largest accomplishments of my career, and it has come out as a book chapter, I have given talks on it, and I have submitted two proposals for funding to test the hypotheses. In the past 90 days, this chapter has been downloaded more than any others in the book (78 times). Other outcomes are our increased knowledge of the possible effects of genetic modification of the cell wall in hybrid poplars. Breeders have aimed to produce hybrid poplars that can made processed into pulp (for paper) using fewer chemicals, and so they have tried to decrease the amount of lignin in the wood. Our work shows that in some situations this low-lignin wood does not serve the trees adequately: the water-conducting cells become crumpled and ineffective, and the wood is too flexible for trees to have normal growth. The impact is that breeders need to be aware of the collateral traits, and to be sure that those traits are still sufficient for tree survivial. Another impact is that scientists have a better understanding of the role of the different chemical components in tree success another outcome is the 18-chapter book that I co-edited, that became available in 2011. In the previous year, the outcome was that the scientists, working in small groups, synthesized information on size- and age-related changes in tree structure and function. The chapters then talked about the next steps for research. The outcome this year is that this book is available to the public. Information was disseminated through teaching Global Issues in Renewable Materials to 14 undergraduates, and Chemistry and Anatomy of Renewable Materials to 5 undergraduate. I advised and mentored 3 MS students, 2 postdocs, and a visiting scientist from Europe, as well as numerous students for whom I am on their graduate committees.

Publications

  • Lachenbruch, B. 2011. Physical models as an aid for teaching wood anatomy. IAWA J. 32:301-312.
  • McCulloh, K.A., F.C. Meinzer, J.S. Sperry, B. Lachenbruch, S.L. Voelker, D.R. Woodruff and J.-C. Domec. 2011. Comparative hydraulic architecture of tropical tree species representing a range of successional stages and wood density. Oecologia 167: 27-37.
  • McCulloh, K.A., D.M. Johnson, F.C. Meinzer and B. Lachenbruch. 2011. An annual pattern of native embolism in upper branches of four tall conifer species. American Journal of Botany 98:1007-1015.
  • Voelker, S., B. Lachenbruch, F.C. Meinzer, P.B. Kitin and S.H. Strauss. 2011. Transgenic poplars with reduced lignin show impaired xylem conductivity, growth efficiency and survival. Plant Cell and Environment 34:655-668.
  • Voelker, S.L., B. Lachenbruch, F.C. Meinzer and S.H. Strauss. 2011. Reduced wood stiffness and strength, and altered stem form, in young antisense 4CL transgenic poplars with reduced lignin contents. New Phytologist 189:1096-1109.
  • Meinzer, F.C., B. Lachenbruch and T.E. Dawson, eds. 2011. Size and Age-Related Changes in Tree Structure and Function. Springer, Dordrecht. 510 pp.
  • Lachenbruch, B., J. Moore and R. Evans. 2011. Radial variation in wood structure and function in woody plants, and hypotheses for its occurrence. pp. 121-164 In: F.C. Meinzer, B. Lachenbruch and T.E. Dawson, eds. Size and Age-Related Changes in Tree Structure and Function. Springer, Dordrecht.
  • Hinckley, T., B. Lachenbruch, F.C. Meinzer and T.E. Dawson. 2011. The whole-lifespan perspective on integration of structure and function in trees. pp. 3-30 In: F.C. Meinzer, B. Lachenbruch and T. Dawson, eds. Size and Age-Related Changes in Tree Structure and Function. Springer, Dordrecht.


Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: I conducted research to elucidate patterns of within-plant variations in wood anatomy, and then to understand the effects of this variation on plant physiology and survival, and on how people can best use the wood. I participated in research on patterns of hydraulic efficiency in different plant groups. One study showed that trees with different wood types (ring-porous, diffuse-porous, and coniferous) have different changes in permeability as trees get larger, and shows the importance of changing frequency of conduits, absolute diameter of conduits, and change in conduit diameter with tree growth on hydraulic efficiency. Another study showed that two coniferous species show coordinated changes in their vulnerability to embolism with the water storage capacity of their wood. Ordinarily, we expect individuals in drier sites to produce wood that can withstand greater water stress before becoming air-blocked (embolized). We found, however, that both conifer species from dry-site populations on the east side of the Cascade Mountains had wood that embolized at less negative water stress than those from more mesic sites, in the Coast Range. We discovered that the dry-site trees had higher availability of stored water, thus buffering the drought such that the east-side, dry-site trees did not experience the drought stress and the wood stayed hydrated. We also published a paper that showed the importance of evaluating water relations of individuals in the context of the plant part being studies. Other work focused on the mechanical role of wood, with studies on hybrid poplars that had modified (lower) lignin and that functioned poorly both mechanically and hydraulically, the later in part because vessels appeared to be misshapen due to weak cell walls. We also reported that the strength of Douglas-fir wood can be estimated from its latewood proportion, which combines both information on the stronger latewood and its quantity. This proportion had a large effect on strength than did microfibril angle over a wide range of growth rates for trees from 17 stands and 1087 samples. Lastly, I co-edited a book on Size- and Age-Related Changes in Tree Structure and Function, and was an author on two of the chapters. I had a close interaction with authors of ten of the chapters, and coordinated the revisions. Information was disseminated through teaching Forests, Wood, and Civilization to 42 undergraduates; Wood and Fiber Anatomy to 12 undergraduates; and Wood Quality to 8 graduate students, using samples and research insights to better teach. I advised and mentored 2 MS students, 2 postdocs, and a visiting scientist from Europe, as well as numerous students for whom I am on their graduate committees. I presented basic wood information to over 2000 3rd and 4th graders and their adult chaperones as part of the Oregon Wood Magic programs in Corvallis (3 days) and Portland (2 days), and spoke about wood quality and anatomy for 40 attendees of a workshop on how to dry wood for quality and profit. Our work that is intended primarily for other scientists was published in six peer-reviewed publications and nine presentations. PARTICIPANTS: The main participants were OSU undergraduates, graduate students, and postdocs. There three undergraduates who worked in the lab as hourly workers. We had two graduate students for whom I was major professor (MS), and other grad students used the lab regularly. They used the lab mainly to use equipment. We had a French student mentored and trained by one of our post-docs for six months. There is much other training that occurred. For example, we have an ongoing weekly lab group meeting for 10 people (two professors, two post-docs, a visiting scientist from Europe, another PhD scientist, and several graduate students and a lab technician). It is run as a mix between a journal club and a class: the speaker gives a 40-min informal lecture with much audience participation, followed by a discussion of the paper were to have read. This period leads to other opportunities, such as the post-doc offering to who the grad students how to do a new technique. Everyone is encouraged to attend professional meetings. TARGET AUDIENCES: The target audiences were varied, including the students of OSU (with their ethnic and racial minorities), my graduate students and post-docs, the 3rd and 4th grade children and their parents, federal congressional aides, the working professionals who attended the workshop in which I was involved (Lumber Drying), and the scientific meetings. The efforts include formal classroom instruction, practicum experiences, the workshops in which I was an invited speaker, and the Wood Magic program for the gradeschool children. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
There was a change in knowledge of scientists from the research showing the importance of interpreting hydraulic data and scaling appropriately, and the importance of water storage as a strategy for drought avoidance. There was a change in knowledge in tree breeders and physiologists that will affect bioenergy and paper industries, from the research on genetically modified cottonwoods showing that reduction in the lignin content of the wood, motivated by lower costs for utilization of the wood for bioenergy or paper, can have extremely deleterious effects on the trees themselves, including poor growth, deposition of other unwanted chemicals, and death. The work suggests that shows that it may be possible to make modest lignin reductions without these severe consequences, but that at present we need more understanding to target these reductions adequately. This type of research may help avoid large economic losses if low-lignin lines become commercially available.

Publications

  • McCulloh, K.A., J.S. Sperry, B. Lachenbruch, F.C. Meinzer and P.B. Reich. 2010. Moving water well: Comparing hydraulic efficiency in twigs and trunks of coniferous, ring-porous, and diffuse-porous saplings from temperate and tropical forests. New Phytologist 186:439-450.
  • Voelker, S.L., B. Lachenbruch, F.C. Meinzer and S.H. Strauss. 2011. Reduced wood stiffness and strength, and altered stem form, in young antisense 4CL transgenic poplars with reduced lignin contents. New Phytologist 189:1096-1109.
  • Voelker, S.L., B. Lachenbruch, F.C. Meinzer, M. Jourdes, C. Ki, A.M. Patten, L.B. Davin, N.G. Lewis, G.A. Tuskan, L. Gunter, S.R. Decker, M.J. Selig, P. Kitin and S.H. Strauss. 2010. Antisense down-regulation of 4CL expression alters lignification, tree growth and saccharification potential of field-grown poplar. Plant Physiology 154:874-886.
  • Lachenbruch, B., G.R. Johnson, G. Downes and R. Evans. 2010. Relationships of density, microfibril angle, and sound velocity with stiffness and strength in mature wood of Douglas-fir. Canadian Journal of Forest Research 40:55-64.
  • Barnard, D.M., F.C. Meinzer, B. Lachenbruch, K.A. McCulloh, D.M. Johnson and D.R. Woodruff. 2011. Climate-related trends in sapwood biophysical properties in two conifers: avoidance of hydraulic dysfunction through coordinated adjustments in xylem efficiency, safety and capacitance. Plant Cell and Environment DOI: 10.1111/j.1365-3040.2010.02269.x
  • Meinzer, F.C., K.A. McCulloh, B. Lachenbruch, D.R. Woodruff and D.M. Johnson. 2010. The blind men and the elephant: The impact of context and scale in evaluating conflicts between plant hydraulic safety and efficiency. Oecologia 164:287-296.
  • Kitin, P., S.L. Voelker, B. Lachenbruch, H. Beeckman, R.C. Meinzer and S.H. Strauss. 2010. Tyloses and phenolic deposits in xylem vessels impede water transport in low-lignin transgenic poplars: a study by cryo-fluorescence microscopy. Plant Physiology 154:1-12.
  • Lachenbruch, B., F. Droppelmann, C. Balocchi, M. Peredo and E. Perez. 2010. Stem form and compression wood formation in young Pinus radiata trees. Canadian Journal of Forest Research 40:26-36.


Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: I conducted research to elucidate patterns of within-plant variations in wood anatomy, and then to understand the effects of this variation on plant physiology and survival, and on how people can best use the wood. More specifically, the work looked at the natural variation in anatomy to better understand the apparent tradeoffs plant have in producing tissues that are optimized for water storage, water transport, and prevention of air bubbles from entering the water column. The work also involved comparing clones of trees that varied in their wood chemistry to understand some of these same tradeoffs, as well as to see how these variations affected tree morphology and survival. Other research involved relating how much heartwood there is in a tree species to how the tree is grown, in a species whose heartwood is prized for its decay-resistance, and understanding the responses of a common tree species to a pathogen in its wood. I have ongoing research that looks at the differences in the wood and wood physiology of populations of three tree species that have subspecies that live to the west of the Cascade Mountains and also that live in the drier, colder eastern side. Regarding dissemination, I taught Wood and Fiber Anatomy to 7 undergrads, using samples that had been collected through research, and examples from the literature and our research. I also taught Forests, Wood, and Civilization to 40 undergraduates, again using samples and insights to better teach. I run an internet bulletin board on wood anatomy (IAWA Forum) with a membership of over 210 researchers, woodworkers, and others from around the world, and in 2009 I changed the interface to make it more useful. It serves as a place for people to discuss their anatomy issues: many of the postings are from people in countries who are unable to travel because of limited budgets or political mandates. I advised and mentored 2 MS students, 1 PhD student, 1 postdoc, and a visiting scientist from Europe, as well as numerous students for whom I am on their graduate committees. I gave a research presentations at a professional meeting in Cayenne, French Guiana and I coauthored presentations that were given at professional meetings in Snowbird, CO, and Santa Cruz, CA. I presented basic wood information to over 2000 3rd and 4th graders and their adult chaperones as part of the Oregon Wood Magic programs in Corvallis (3 days) and Portland (2 days), and spoke about wood quality and anatomy for 40 attendees of a workshop on how to dry wood for quality and profit. Our work that is intended primarily for other scientists was published in five peer-reviewed publications and numerous presentations. PARTICIPANTS: The main participants were OSU undergraduates, graduate students, and postdocs. There four undergraduates who worked in the lab as hourly workers. We had three graduate students for whom I was major professor (two MS and one PhD), and another eight grad students used the lab regularly. They used the lab mainly to use equipment, but instructed them on it and often helped with interpretation of results, as well. There were three people with PhDs regularly in the lab: two post-docs (one a woman), and a visiting scientists here from Europe on a mid-career Marie Curie EU Fellowship. I mentored everyone except the student workers, who worked directly with the other people in the lab. We had a French student mentored and trained by one of our post-docs for six months. There is much other training that occurred. For example, we have an ongoing weekly lab group meeting for 10 people (two professors, two post-docs, the visiting scientist, another PhD scientist, and several graduate students and a lab technician). It run like a mix between a journal club and a class: the speaker gives a 40-min informal lecture with much audience participation, followed by a discussion of the paper were to have read. This period leads to other opportunities, such as the post-doc offering to who the grad students how to do a new technique. Everyone is encouraged to attend professional meetings. TARGET AUDIENCES: The target audiences were varied, including the students of OSU (with their ethnic and racial minorities), my graduate students and post-docs, the 3rd and 4th grade children and their parents, federal congressional aides, and the working professionals who attended the two workshops in which I was involved (Wood Quality, and Lumber Drying). The efforts include formal classroom instruction, practicum experiences, the workshops in which I was an invited speaker, and the Wood Magic program for the gradeschool children. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
There was a change in knowledge of scientists from the research showing the importance of water storage as a strategy for drought avoidance. Most scientists in this field write that trees make wood that is constructed to be highly conductive (large, frequent conduits) or that is highly resistant to embolism (smaller conduits, stronger walls, smaller inter-conduit openings, etc.). In fact, many species can have the highly-conductive wood and release water from storage in order to avoid the water tensions that would have caused embolisms to enter the water stream. The hydraulics research also showed how vasculature scales with leaf and plant size, giving needed information to tree and crop breeders as they work toward drought tolerance. The work also adds to knowledge of use to land managers dealing with changing climate who are trying to find appropriate species for a region or appropriate regions for a species. There was a change in knowledge of importance to disease management for a tree pathogen involving understanding of the cause of death from the disease, with implications for how to better diagnose, and potentially manage, the disease. For example, one of the themes of the IUFRO meeting on Phytophthora, to be held with 100 scientists from around the world in New Zealand in 2010, is the cause of death by these pathogens: loss of phloem function or xylem function, or effects of transportable substances (toxins or other signals) elsewhere in the tree. The research done here on trees inoculated with Phytophthora ramorum showed a strong negative effect on water transport, and it characterized the mechanisms by which this occurred, giving evidence in the debate for the effect of disease on xylem. It also enabled the next steps to be proposed, of phonological observation of drying and dying in trees from which various proportions of phloem and xylem are removed, to further understand the mechanisms and aid in diagnosis. There was a change in knowledge in tree breeders and physiologists that will affect bioenergy and paper industries, from the research on genetically modified cottonwoods showing that reduction in the lignin content of the wood, motivated by lower costs for utilization of the wood for bioenergy or paper, can have extremely deleterious effects on the trees themselves, including poor growth, deposition of other unwanted chemicals, and death. The work suggests that shows that it may be possible to make modest lignin reductions without these severe consequences, but that at present we need more understanding to target these reductions adequately. This type of research may help avoid large economic losses if low-lignin lines become commercially available.

Publications

  • Barnard, D., B. Lachenbruch and F. Meinzer. 2009. Radial water transport and sapwood use efficiency of two conifers from contrasting climate regimes in the Pacific Northwest. Biology and Mycology 2009, Abstracts published online. 1 p. Botanical Society of America. http://2009.botanyconference.org/engine/search/index.phpfunc=detail& aid=925
  • Collins, B.R., J.L. Parke, B. Lachenbruch and E.M. Hansen. 2009. The effects of Phytophthora ramorum infection on hydraulic conductivity and tylosis formation in tanoak sapwood. Canadian Journal of Forest Research 39:1766-1776.
  • DeBell, J. and B. Lachenbruch. 2009. Heartwood/ sapwood variation of western redcedar as influenced by cultural treatments and position in tree. Forest Ecology and Management 256:2026-2032.
  • Domec, J.C., J.M. Warren, F.C. Meinzer and B. Lachenbruch. 2009. Safety factors for xylem failure by implosion and air-seeding within roots, trunks and branches of young and old conifer trees. IAWA J. 30:100-120.
  • Kitin, P., B. Lachenbruch and H. Beeckman. Variations of xylem fiber morphology and function in angiosperms. 2009. Biology and Mycology 2009, Abstracts published online. 1 p. Botanical Society of America. http://2009.botanyconference.org/engine/search/index.phpfunc=detail& aid=497
  • Kitin, P., S.L. Voelker, B. Lachenbruch, H. Beeckman, F. Meinzer and S.H. Strauss. 2009. Transgenic poplars with very low lignin in their cell walls produce tyloses and phenolic deposits in xylem vessels that impede water transport: A study by cryo-fluorescence microscopy. Biology and Mycology 2009, Abstracts published online. 1 p. Botanical Society of America. http://2009.botanyconference.org/engine/search/index.phpfunc=detail& aid=909
  • Lachenbruch, B., S.L. Voelker, F.C. Meinzer and S.H. Strauss. 2009. Structural and functional differences among transgenic hybrid poplar lines with varying lignin contents. Proceedings, Plant Biomechanics Conference. Cayenne, French Guiana. 8 p.
  • McCulloh, K.A., J.A. Sperry, F.C. Meinzer, B. Lachenbruch and C. Atala. 2009. Murray's law, the 'Yarrum' optimum, and the hydraulic architecture of compound leaves. New Phytologist 184:234-244.
  • Meinzer, F.C., D.M. Johnson, B. Lachenbruch, K.A. McCulloh and D.R. Woodruff. 2009. Xylem hydraulic safety margins in woody plants: Coordination of stomatal control of xylem tension with hydraulic capacitance. Functional Ecology 23:922-930.
  • Parke, J., B. Collins, B. Lachenbruch and E. Hansen. 2009. Effects of Phytophthora ramorum infection on hydraulic conductivity and tylosis formation in tanoak sapwood. Fourth Sudden Oak Death Science Symposium, Meeting Abstracts. USDA Forest Service Pacific Southwest Research Station. p. 26. (http://nature.berkeley.edu/comtf/sodsymposium4/)


Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: I conducted research on the limitations of water transport in trees that led to publications on maximum height, as well as on adaptive changes that occur in the foliage and its physiology at the top of tall trees. I also conducted research on wood anatomy, focusing on the elements that run in the radial direction, as well as on the impact of their abundance on radial water movement and the radial movement of wood preservatives. Most of this work is at an early stage. I taught Wood and Fiber Anatomy to 9 undergrads and 3 grad students, animating the class with samples that had been collected through research, and examples from the literature and our research. I also taught Forests, Wood, and Civilization to 48 undergraduates, again using samples and insights to better teach. As a member of an international team, I evaluated the first wood science program outside of North America that had requested to be accredited by the Society of Wood Science and Technology, in Concepcion, Chile. I advised and mentored 3 MS students, 1 PhD student, and 3 postdocs directly, as well as numerous students for whom I am on their graduate committees. I directed 2 senior (undergraduate) theses in our research areas, as well. I personally gave research presentations at professional meetings in Vancouver and Concepcion, Chile, and I coauthored presentations that were given at professional meetings in Fullerton, CA, Portland, OR, Perth, Australia, and Milwaukie, WI. I presented both days at a 2-day workshop on Wood Quality in Washington State to 80 participants, and talked at the Lumber Drying Workshop in Corvallis, OR to 40 participants. I also delivered a research seminar to my home department. One PhD dissertation resulted. Regarding dissemination, I presented basic wood information to over 2000 3rd and 4th graders and their adult chaperones as part of the Oregon Wood Magic programs in Corvallis (3 days) and Portland (2 days). I gave a presentation on the ways a particular research site has been used and the networks that have developed, in Carson, WA to Oregon and Washington federal legislators and aids during their field tour of the Canopy Crane. I spoke about the basics of wood anatomy and quality, and what we are still learning, to an industry group of 35 people, in the First Annual Portland Wholesale Lumber Association Forestry Innovation Summit, in Corvallis. Our research paper on tall trees was released as an AP Press Release, and as such, it was picked up by many newspapers including the national USA Today, and the Telegraph in London. I was interviewed by phone by a number of journalists, including the Telegraph writer, and I was asked questions by e-mail by several more, including a journalist for the magazine from Kew Gardens near London. I responded to e-mails from laypeople from the US, Canada, South America, and Europe, and I was interviewed live for 15 minutes by the Jefferson Public Radio station in Ashland, OR. Our work that is intended primarily for other scientists was published in five peer-reviewed publications and numerous presentations. PARTICIPANTS: The main participants were Oregon State University undergraduates, graduate students, and postdocs. There were two undergraduates who did their senior theses in our lab with us (one of whom is a female Hispanic), and five undergraduates who worked in the lab as hourly workers. We had five graduate students for whom I was major professor (three MS and two PhD) (two of whom are women, one hispanic), and another eight or ten grad students used the lab regularly. They used the lab mainly to use equipment, but instructed them on it and often helped with interpretation of results, as well. There were three people with PhDs regularly in the lab: two post-docs (one a woman), and a visiting scientist here from Europe on a mid-career Marie Curie EU Fellowship. I mentored everyone except the student workers, who worked directly with the other people in the lab. There is much training that occurred. For example, we have an ongoing weekly lab group meeting for 10 people (two professors, two post-docs, the visiting scientist, another PhD scientist, and several graduate students and a lab technician).It is run like a mix between a journal club and a class: the speaker gives a 40-min informal lecture with much audience participation, followed by a discussion of the paper we were to have read. This period leads to other opportunities, such as the post-docs offering to show the grad students how to do a new technique. Everyone is encouraged to attend professional meetings. I encouraged the two post-docs to teach a class, which they did in 2008. TARGET AUDIENCES: The target audiences were varied, including the students of OSU (with their ethnic and racial minorities), my graduate students and post-docs, the 3rd and 4th grade children and their parents, federal congressional aides, and the working professionals who attended the two workshops in which I was involved (Wood Quality, and Lumber Drying). The efforts include formal classroom instruction, practicum experiences, the workshops in which I was an invited speaker, and the Wood Magic program for the gradeschool children. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
There was a change in knowledge of the public resulting from our work on height limitations in tall trees. We showed that the height of tall Douglas-fir trees is limited by the ability of trees to exclude air bubbles from the water transport cells. It is physically possible to produce cells with valves to keep the air bubbles out, but the anatomy required for this adaptation would cause the water transport to decline too much to sustain life. Many private citizens from around the world contacted us with interest about the findings, and many scientists contacted us as well. The research on genetically modified cottonwoods has attracted attention from scientists because it challenges the idea that the mutants are strong and stable enough to grow and that they produce wood that is suitable for water transport. Our research shows that even small changes in the amount of lignin in the wood causes decreases in wood strength and stiffness, and that trees with less lignin produce shorter squatter stems, in order to maintain their safety factor against buckling. Moreover, as the amount of lignin in the wood decreases, the amount of wood that is gummed up and reddish brown increases. The phenolic deposits sit within the vessels, and we have measured a precipitous decrease in water transport and in overall biomass in these trees. There was a change of knowledge in the 48 students in my Forests, Wood, and Civilization class that focused on critical thinking skills when looking at natural resource issues. At the end of the class, students were also much more knowledgeable about the spectrum of issues that must be considered, and the important positive roles of forests and wood in their lives. There was a change in actions resulting from my workshop presentation in which I showed data that growth rate has very little negative impact on the strength or stiffness of Douglas-fir. The practitioners in the workshop said that this research was very important to them in how they could market their fast-grown wood.

Publications

  • Woodruff, D.R., F.C. Meinzer, B. Lachenbruch and Johnson, D.M. 2008. Coordination of leaf structure and gas exchange along a height gradient in a tall conifer. Tree Phys. 29:261-272.
  • Woodruff, D.R., F.C. Meinzer, B. Lachenbruch, K. McCulloh, J.M. Warren and D.M. Johnson. 2008. Leaf hydraulic regulation of water flux in Douglas-fir. Invited paper. ESA Ann. Mtg., Milwaukee, WI. (1 p. abstr.).
  • Voelker, S.L., F.C. Meinzer, B. Lachenbruch, R.P. Guyette and R.M. Muzika. 2008. Increases in tree productivity across the extra-tropical northern hemisphere during the Anthropocene: On the role of tree age and nitrogen deposition. ESA Ann. Mtg., Milwaukee, WI. (1 p. abstr).
  • Domec, J.-C., B. Lachenbruch, F.C. Meinzer, D.F. Woodruff, J.M. Warren and K.A. McCulloh. 2008. Maximum height in a conifer is associated with conflicting requirements for xylem design. Proc. Nat. Acad. Sci. 105:12069-12074.
  • Dunham, S.M., L.M. Ganio, A.I. Gitelman, A.I. and B. Lachenbruch. 2008. Partitioning variation in Douglas-fir xylem properties among multiple scales via a Bayesian hierarchical model. Tree Phys. 28:1017-1024.
  • Kitin, P., B. Lachenbruch and H. Beeckman. 2008. An inexpensive cryo-system for sliding microtome and light microscopy. Bot. Soc. of Am. Ann. Mtg.
  • Kitin, P., B. Lachenbruch and H. Beeckman. 2008. Microstructure of water paths in xylem visualized by resin-casting and SEM. Structure and function of plant hydraulic systems. Fullerton Arb. and Dept. Biol. Sci., Cal. State Univ. Fullerton. Prog. Abst. Book.
  • Lachenbruch, B., J.-C. Domec, F. Meinzer, D.R. Woodruff, J. Warren and K.A. McCulloh. 2008. Ultimate height of Douglas-fir trees appears related to water transport safety vs. efficiency through the bordered pits. Bot. Soc. of Am. Ann. Mtg., Vancouver, B.C.
  • Lachenbruch, B. and F. Droppelmann. 2008. Effects of stem inclination on compression wood formation in young radiata pine trees. Proc. Ann. Conv. Soc. Wood Sci. & Technol. Concepcion, Chile. 8 p.
  • McCulloh, K., J. Sperry, F. Meinzer and B. Lachenbruch. 2008. Safety versus efficiency in hydraulic architecture. Ecohydrology and Ecophysiology of Plants in Water-Limited Environments Workshop, Perth, Australia. School of Plant Biol. and ARWA Centre for Ecohydrol., Prog. Abst. Book.
  • McCulloh, K., J.S. Sperry, F.C. Meinzer and B. Lachenbruch. 2008. The scaling of safety versus efficiency in hydraulic architecture. ESA Ann. Mtg., Milwaukee, WI. (1 p. abstr).
  • Meinzer, F.C. J.-C. Domec, B. Lachenbruch, D.R. Woodruff, J.M. Warren and K. McCulloh. 2008. Ultimate height in a conifer is associated with conflicting requirements for xylem design. ESA Ann. Mtg., Milwaukee, WI. (1 p. abstr).
  • Taylor, M.A., J.R. Brooks, B. Lachenbruch, J.J. Morrell and S. Voelker. 2008. Correlation of carbon isotope ratios in the cellulose and wood extractives of Douglas-fir. Dendrochron. 26:125-131.
  • Woodruff, D.R. 2008. Height-related trends in structure and function of Douglas-fir foliage. Ph.D. Dissertation. Department of Forest Science, Oregon State Univ., Corvallis.
  • Woodruff, D.R., F.C. Meinzer and B. Lachenbruch. 2008. Height-related trends in leaf xylem anatomy and hydraulic characteristics in a tall conifer: Safety versus efficiency in foliar water transport. New Phytol. 180:90-99.


Progress 01/01/07 to 12/31/07

Outputs
OUTPUTS: The top story from our research this year is the documentation and modeling to show that xylem anatomy changes systematically with height in trees. In fact, the work suggests that the xylem may well control maximum height that Douglas-fir trees can attain. It also shows systematic changes in foliar xylem morphology at increasing heights. There is much more tension in the sap (the xylem water) at height than at ground level, mostly because of the effect of gravity pulling downward on the water at height, but partly because of some resistance that occurs because of the longer path the water travels to get to these heights. Using morphological measurements of xylem from several heights in trees up to 85m high (almost 30 storeys high) we modeled that the tension at which the xylem will embolize through air-seeding increases markedly with height. Airs-seeding occurs when a bubble is pulled into a conducting cell, and because the tension is so much greater with height, it makes sense that the tree would benefit from this adaptation. The cost of this adaptation, however, is that the resistance to water transport increases greatly. Extrapolation of the data suggest that if the xylem will approach zero conductivity (no water can be transported) at a height of 109-138 m, which is consistent with historic height records of 100-127 m for this species. The research focused on the pits, whose morphology changes significantly with height. The main driver is the size of the margo relative to the torus-the margo becomes relatively larger with height, which allows greater tensions before air-seeding, but which impedes water transport. In the foliage, xylem at height has thicker walls and smaller lumens, and also can transport water at much higher tensions without embolizing than can the foliar xylem lower in the tree. Other work on Douglas-fir xylem showed its variable morphology from location to location within trees. Tracheid diameter, tracheid length, number of pits per cell, specific conductivity, and vulnerability to embolism decreased vertically from the roots to the branches. Correlations were evident between some positions for tracheid diameter, percent earlywood, pits per cell, and vulnerability to embolism. We found evidence for large scale relationships (among all observations from all trees) between density and tracheid diameter, specific conductivity and diameter, vulnerability and diameter, specific conductivity and pits per cell, and vulnerability and pits per cell. However, surprisingly, at a smaller scale of within position, only the branches and roots maintained most of these relationships. Our research was published that showed that there is radial variation in wood properties in branches and in roots of Douglas-fir, but that the pattern of variation is different from the pattern exhibited in trunks. Roots differed most strikingly from both trunks and branches in having extremely long tracheids near the pith and no change in tracheid length along the radius. In contrast, tracheids are short near the pith in trunks and branches, and become gradually longer with radial position. PARTICIPANTS: Lachenbruch, B., Principal Investigator; Training or Professional Development: two Oregon State University PhD students (Steve Voelker, David Woodruff); and three undergraduate students.

Impacts
The research has yielded a number of publications, but the work on tree height is represented by only one published paper, two that are submitted, and several talks both given and planned. The tree height research will have a large impact on a quickly moving and competitive field in which many researchers are seeking to understand the limits to growth. Elucidation of the mechanisms that control growth are essential for people who are modeling global carbon budgets and those who are working on new, more sustainable forest practices. There is a limited effect on forest products in that it is not expected that the very old trees in North America will be harvested to a large extent, although the research does give us data about what to expect from trees with accelerated growth that are being groomed to produce old growth properties. The research showing the degrees of similarities and differences in plant parts of Douglas-fir xylem will inform discussions of full utilization of wood from trees. It shows unequivocal differences of branches and tree tops from the rest of the tree but indicates that the root wood is similar to the bole wood nearby. It also informs the ecophysiological discussions that are incorrectly studying branch tips and extrapolating their function to bole, which simply can not be done. It also indicates that the standard features used by ecophysiologists to explain physiology (such as wood density and cell length) do not explain physiology beyond the organ in which they are studied, so they are not the major factors determining the behavior. The research on radial patterns of wood anatomy in branch, root, and trunk wood are groundbreaking in that they show definitively that the cambium (the organ from which the xylem cells are generated) can and does produce long cells from the very first growth ring. This result disproves one of the prevailing ideas that the cambium needs to mature in order to make progressively longer cells. Thus, from the point of view of development, potentially mature wood could be made from the very first growth ring.

Publications

  • Woodruff, D.R., F.C. Meinzer and B. Lachenbruch. 2007. Height-related trends in leaf xylem anatomy and hydraulic characteristics in Douglas-fir: Safety versus efficiency of water transport. (One-Page Abstract). Annual Meeting of the Ecological Society of America, San Jose, CA. http://eco.confex.com/eco/2007/techprogram/P6356.HTM
  • Domec, J-C., F.C. Meinzer, B. Lachenbruch and J. Housset. 2007. Dynamic variation in sapwood specific conductivity in six woody species: Impact on the efficiency of the water transport system in living trees. Tree Physiology 27:1389-1400.
  • Dunham, S.M., B. Lachenbruch and L.M. Ganio. 2007. Bayesian analysis of Douglas-fir hydraulic architecture at multiple scales. Trees 21:65-78.
  • Lachenbruch, B., S.M. Dunham and L.M. Ganio. 2007. Roots, branches, and trunk different greatly in their xylem structure and function in Douglas-fir. (One-Page Abstract). Annual Meeting of the Ecological Society of America, August 5-10, San Jose, CA. http://eco.confex.com/eco/2007/techprogram/P7506.HTM
  • McCulloh, K., F.C. Meinzer, J. Sperry and B. Lachenbruch. 2007. Hydraulic design criteria for compound leaves. (One-Page Abstract). Annual Meeting of the Ecological Society of America, August 5-10, San Jose, CA. http://eco.confex.com/eco/2007/techprogram/P7431.HTM
  • McCulloh, K.A., K. Winter, F.C. Meinzer, M. Garcia, J. Aranda and B. Lachenbruch. 2007. A comparison of daily water use estimates using constant heat sap-flow probes and gravimetric measurements in pot grown saplings. Tree Physiology 27:1355-1360.
  • Parke, J., Collins, B., Buckles, G., Hansen, E., Lachenbruch. B. 2007. Spread of infection within tanoak trees inoculated with Phytophthora ramorum. Fourth IUFRO Working Party 7.02.09, Phytophthoras in Forests and Natural Ecosystems, August 26-31, Monterey, CA.
  • Parke, J., E. Hansen, G. Buckles, S. Voelker, B. Collins, B. Lachenbruch and E. Oh. 2007. Phytophthora ramorum infects sapwood and is associated with reduced specific conductivity of xylem vessels in tanoak. Sudden Oak Death Science Symposium III, March 5-9, Santa Rosa, CA.
  • Parke, J.L., E. Oh, S. Voelker, E.M. Hansen, G. Buckles and B. Lachenbruch. 2007. Phytophthora ramorum colonizes tanoak xylem and is associated with reduced stem water transport. Phytopathology 97:1558-1567.
  • Peterson, M.G., H.R. Dietterich and B. Lachenbruch. 2007. Do Douglas-fir branches and roots have juvenile wood? Wood and Fiber Science 39:651-660.
  • Silva, J.A., B.L. Gartner and J.J. Morrell. 2007. Towards the development of accelerated methods for assessing the durability of wood plastic composites. Journal of Testing and Evaluation 35:203-210.
  • Taylor, A.M., J.R. Brooks, B. Lachenbruch and J.J. Morrell. 2007. Radial patterns of carbon isotopes in the xylem extractives and cellulose of Douglas-fir. Tree Physiology 27:921-927.
  • Voelker, S.L., F.C. Meinzer, S.H. Strauss and B. Lachenbruch. 2007. Low-lignin transgenic poplar: Is there a trade-off between enhanced fiber production and biomechanical stability? (One-Page Abstract). Annual Meeting of the Ecological Society of America, August 5-10, San Jose, CA. http://eco.confex.com/eco/2007/techprogram/P8053.HTM
  • Woodruff, D.R., K.A. McCulloh, J.M. Warren, F.C. Meinzer and B. Lachenbruch. 2007. Impacts of tree height on leaf hydraulic architecture and stomatal control in Douglas-fir. Plant Cell and Environment 30:559-569.


Progress 01/01/06 to 12/31/06

Outputs
Our research on inter-tracheid pits extends our understanding of the mechanisms by which pits aspirate and the location through which air leaks into tracheids in Douglas-fir. When water flows through a conifer tree, it has to enter and exit long thin closed cells (tracheids) through the membrane-covered pits. In a 30-m tall conifer, water will traverse at least 75,000 pits, which confers considerable resistance. However, their main purpose is to close off tracheids to contain embolisms should an air bubble end up within a tracheid. We were able to calculate that, consistent with earlier work in the field, earlywood membranes are flexible enough and their pit chambers narrow enough that the membrane can distend to cover the pit chamber, and because the center of the membrane is impermeable, to transport. However, our calculations show an unreported mechanism for the most common air-seeding of earlywood: when the membrane is under higher enough pressure after it aspirates, it will be extruded partway into the tracheid cavity, and air bubbles will pass from one tracheid to another through the margo at the edge of the torus. Again, consistent with earlier studies, in latewood, the membranes are not sufficiently flexible to move all the way across the pit chamber (which is larger than in earlywood) and so the latewood pits do not become closed off if there are pressure differences among tracheids. We also calculated that at the top, where the water is under much tension because of the weight of the water column, the pressure difference required to pull an air bubble through a pore is much higher than at the bottom of a tree. In other work, we studied how heartwood decay resistance varies when western redcedar trees are fertilized and/or thinned, practices that will change the balance of resources available to the tree for manufacturing defensive compounds that could be placed into the heartwood. There was no consistent relationship between growth rate and extractive content within trees, and the fertilization and thinning treatments had no significant effect on the average extractive levels of the trees. The physiological state of the tree, as represented by sapwood extractive content, was weakly related to heartwood extractive concentration. Lastly, we synthesized information on the probable reasons that trees make juvenile wood: mechanical explanations (to be able to bend in the wind when twigs are small, to have strength when the tree is large) and hydraulic explanations (to withstand drought and still maintain water transport when small, to have sufficient water transport capacity when large). Analyses suggest that the hydraulic explanations are more consistent with tree biology than mechanical explanations.

Impacts
The pit research suggests that trees produce pits with characteristics that are essential for their physiological function, and these characteristics vary from the bottom of the tree to the top of a tree. This research suggests that tree height may be limited by pit design. In wood processing, this research suggests that the top log will differ from the bottom log in drying properties, aspiration, and the treatability (all of which relate to the permeability of the material and the conditions under which pits aspirate). The research on heartwood shows that in western redcedar the manner in which the tree is grown has little discernible effect on the decay resistance. This result is good news for tree growers because it implies, at least within the range of trees studied, that silvicultural practices that boost the growth rate will not have adverse effects on decay resistance. The synthesis of causes of juvenile/mature wood changes in trees (i.e., why are trees designed to produce one type of xylem when young and small and another type when older and larger) suggests that hydraulics is more important than mechanics. Given that trees are being harvested at younger ages, more wood in the lumber yard is juvenile wood than in the past. Silviculturists and tree breeders seeking ways to produce young wood with more mature-wood properties must take into account how their modifications affect the hydraulics of the trees.

Publications

  • Taylor, A.M., B.L. Gartner, J.J. Morrell and K. Tsuoda. 2006. Effects of heartwood extractive fractions of Thuja plicata and Chamaecyparis nootkatensis on wood degradation by termites or fungi. Journal of Wood Science 52:47-153.
  • Gartner, B.L. 2006. Abstracts and Proceedings. Why do coniferous trees produce juvenile wood? Symposium on a century of wood anatomy and 75 years of IAWA. Botanical Society of America 2006. Chico, CA, http://www.2006.botanyconference.org/engine/search/index.php (one page abstract).
  • Marshall, H.D., G.E. Murphy and B. Lachenbruch. 2006. Effects of bark thickness estimates on optimal log merchandising. Forest Products Journal 56(11/12/):87-92.
  • Taylor, A.M., B.L. Gartner and J.J. Morrell. 2006. Western redcedar extractives: Is there a role for the silviculturist? Forest Products Journal 56:58-63.
  • Johnson, G.R. and B. Lachenbruch. 2006. Wood quality of coastal Douglas-fir: effects of growth rate and genetics. Proceedings, National Workshop on Forest Productivity and Technology: Cooperative Research to Support a Sustainable and Competitive Future. Washington, DC. Nov. 8-9. Sponsored by the USDA Forest Service in Partnership with Agenda 2020 Technology Alliance, American Forest & Paper Association, National Council for Air & Stream Improvement, and U.S. Department of Energy (one-page abstract)
  • Johnson, G. R. and B. Lachenbruch. 2006. Effects of radial growth rate on wood properties in mature wood in coastal Douglas-fir. Washington, DC. National Workshop on Forest Productivity and Technology: Cooperative Research to Support a Sustainable and Competitive Future, November 8-9. Sponsored by the USDA Forest Service in Partnership with Agenda 2020 Technology Alliance, American Forest & Paper Association, National Council for Air & Stream Improvement, and U.S. Department of Energy (one-page abstract).
  • Lachenbruch, B. 2006. Biological basis of wood quality: Utility of research and future directions. Proceedings, Wood Science and Technology in 2100 meeting, International Academy of Wood Science, Melbourne, Australia. (one-page abstract; no page numbers).
  • DeBell, D.S., C.A. Harrington, B.L. Gartner and R. Singleton. 2006. Time and distance to clear wood in pruned red alder saplings. p. 103-113 In: Red Alder, A State of Knowledge. R.L. Deal and C.A. Harrington, eds. General Technical Report PNW-GTR 669. USDA Pacific Northwest Research Stastion, Portland, OR. 150 p.
  • Domec, J.C., B. Lachenbruch and F.C. Meinzer. 2006. Bordered pit structure and function determine spatial patterns of air-seeding thresholds in xylem of Douglas-fir (Pseudotsuga menziesii; Pinaceae) trees. American Journal of Botany 93:1588-1600.
  • Gartner, B.L. and G.R. Johnson. 2006. Is long primary growth associated with stem sinuosity in Douglas-fir? Canadian Journal of Forest Research 36:2351-2356.
  • Johnson, G.R. and B.L. Gartner. 2006. Genetic variation in basic density and MOE of coastal Douglas-fir. Tree Genetics Genomes 3:25-33.


Progress 01/01/05 to 12/31/05

Outputs
1) Juvenile wood has inferior properties to mature wood for almost all structural applications, and yet we do not know why trees produce it. To understand whether it is a requirement of the cambial growth strategy of plants, we described the radial patterns of two characteristics (density and tracheid length) for trunks of Douglas-fir (for which juvenile wood is well characterized) as well as branches and roots of the same trees (for which it is not well-characterized). We found that there were subtle variations in the patterns of density from the pith outward in all three organs, but that one could still define a juvenile and mature wood zone based on density. However, with respect to tracheid length, there was no radial pattern in the roots; the branches showed the pattern typical of stems, with increasing lengths from the pith outwards. 2) In a review chapter, I examined whether evidence suggests that the radial changes in wood properties (the juvenile to mature wood transition) occur for hydraulic or mechanical reasons. The majority of evidence suggested that hydraulics are more important than mechanics. 3) In a third project, we characterized the effects of tree age and stem position on axial and radial water transport (called specific conductivity, ks) and native embolism, in trunks of young and old-growth ponderosa pine. Young trees had lower ks and were less embolized (with embolism levels that corresponded to a 5% loss of conductivity) than anywhere in the trunk of the old-growth trees, suggesting that young trees have physiological strategies that are more risk-avoiding than old trees. In the old-growth trees, the outer sapwood had 25% to 50% higher ks than inner sapwood. Interestingly, there were no significant radial differences in level of embolism, suggesting that if embolisms did occur, they could be refilled to the same degree at different radial positions, despite the 140-years difference in wood age from inner to outer sapwood.

Impacts
Silvicultural and tree-breeding programs are grappling with the negative effects of juvenile wood on wood properties as the rotation age of plantation trees drops, and a higher proportion of juvenile wood is harvested. If the physiological role of juvenile wood is understood, then programs can be developed to maintain the essential physiological function of the juvenile wood while minimizing the negative characteristics. For example, it may be possible to develop lines of trees with both high drought tolerance in the wood, and good mechanical properties, but only if one is aware of the need to not breed mal-adaptive traits. The research characterizing ponderosa pine wood and its function adds considerably to our knowledge of wood physiology in this species. It is a species with extremely thick sapwood, and this research shows that the inner sapwood, which could be 140 years older than outer sapwood, was still capable of substantial water transport, and is not actually just inert wood like heartwood. However, inner sapwoods lower levels of water transport ability than outer sapwood suggest that when people make the familiar sapwood area/leaf area calculations to estimate tree vitality, inner sapwood area should be discounted substantially because it is not capable of transporting as mch water. The fact that 140-year old sapwood has similar levels of embolism to 10-year old sapwood suggests that the mechanism for refilling embolisms is very robust.

Publications

  • Maton, C. and B.L. Gartner. 2005. Do gymnosperm needles pull water through the xylem produced in the same year as the needle? American Journal of Botany 92:123-131. Meinzer, F., B. Bond, R. Brooks, J.-C. Domec, B. Gartner, J. Warren and D. Woodruff. 2005. Trees and water: coping with being large. p. 56-57 In: Proceedings, Annual Meeting of the Northwest Scientific Association, Corvallis, OR.
  • Olszyk, D., M. Apple, B.L. Gartner, R. Spicer, C. Wise, E. Buckner, A. Benson-Scott and D. Tingey. 2005. Xeromorphy increases in shoots of Pseudotsuga menziesii (Mirb.) Franco seedlings with exposure to elevated temperature but not elevated CO2. Trees: Structure and Function 19:552-553.
  • Pruyn, M.L., M.E. Harmon and B.L. Gartner. 2005. Storage versus substrate limitation to bole respiratory potential in two coniferous tree species of contrasting sapwood width. Journal of Experimental Botany 56:2637-2649.
  • Renninger, H., B. Gartner and R. Meinzer. 2005. Douglas-fir vs. western hemlock: Is hydraulic architecture a constraint on release from suppression? Proceedings, Annual Meeting of the Ecological Society of America. On CD.
  • Domec J.-C., F.C. Meinzer, B.L. Gartner and J. Housset. 2005. Dynamic variation in xylem conductivity: Mechanisms and consequences for water movement through sapwood. p. 238 In: Abstracts of the 17th International Botanical Congress, Vienna, Austria.
  • Domec, J.-C., M.L. Pruyn and B.L. Gartner. 2005. Axial and radial profiles in conductivities, water storage and native embolism in trunks of young and old-growth ponderosa pine trees. Plant, Cell and Environment 28:1103-1113.
  • Dunham, S.M., L.M. Ganio and B.L. Gartner. 2005. Hierarchical analysis of structural and functional tradeoffs in hydraulic properties of Douglas-fir xylem. Proceedings, Annual Meeting of the Ecological Society of America. On CD.
  • Gartner, B.L. 2005. Assessing wood characteristics and wood quality in intensively managed plantations. Journal of Forestry (March):75-77.
  • Gartner, B.L. and F.C. Meinzer. 2005. Structure-function relationships in sapwood water transport and storage. Chapter 15. p. 307-331 In: Vascular Transport in Plants. M. Zwieniecki and N. M. Holbrook, eds. Elsevier/Academic Press, Oxford.
  • Grotta, A.T., B.L. Gartner, S.R. Radosevich and M. Huso. 2005. Influence of red alder competition on cambial phenology and latewood formation in Douglas-fir. IAWA J. 26:309-324.
  • Grotta, A.T., R.J. Leichti, B.L. Gartner and G.R. Johnson. 2005. Effect of growth ring orientation and placement of earlywood and latewood on MOE and MOR of very-small clear Douglas-fir beams. Wood and Fiber Science 37:207-212.
  • Johnson, R. and B. Gartner. 2005. Variation of wood quality in coastal Douglas-fir: A report to the Trask Breeding Cooperative. 1 page.
  • Johnson, R. and B. Gartner. 2005. Variation of wood quality in coastal Douglas-fir. Proceedings, 2005 Southern Forest Tree Improvement Conference. Raleigh, NC.


Progress 01/01/04 to 12/31/04

Outputs
Most conifers have leaves that remain attached to the tree for several years. We investigated whether when old leaves transpire, they withdraw water from the growth ring that was made when the leaf was made, or whether the leaves develop connections with newer xylem rings. The previous literature (1903,1929,1937) suggested only one pattern: that leaves sever connections with old wood and develop new connections annually. Only four of the 16 species showed this pattern. Four others showed that 2-year old needles withdrew water primarily through 2-year old wood and in four species the 2-year old needles withdrew water primarily through 1-year old (not new) wood in four species, and through current-year's wood. In the remaining four species, there were no clear patterns. Numerous reports of sap flow in living trees have shown that the highest flow is not in the outermost sapwood, but inward by as much as several centimeters. Given realistic radial growth rates and leaf longevities, and on the basis of the leaf attachment research, it is unlikely that the pattern of peaked sap flow is caused by evapotranspiration from the old cohorts of leaves with attachments in the old xylem. We have begun research on the design criteria for the shape of tracheids in Douglas-fir. Clearly they need to be hollow and elongated with sufficiently strong cell walls to avoid implosion in drought, but are the different shapes in trunks (wide, long), branches (narrow, moderate length), and roots (probably wide and relatively short) designed to have similar resistances, given the water's viscosity in vivo? We measured sap flux and sap temperature (to estimate viscosity) in branches, boles, and roots of 50-year old trees (n=36 trees total). Then we harvested the trees to measure specific conductivity and vulnerability to embolism of the three organs. We are currently beginning to section wood to analyze their anatomy (tracheid length and diameter in the earlywood and latewood, pit frequency and size, cell wall thickness, and latewood %). In a related project, we are investigating whether the pith-to-bark pattern of wood density and tracheid length that is typical of boles, is also found in roots and branches. If it is not, this pattern will raise questions about sapwood function in the three organs. Lastly, we have begun research on whether western hemlock saplings can release from overstory suppression more rapidly than Douglas-fir saplings (as silviculturists say they observe), and if so, whether the reason is that suppressed western hemlocks are less hydraulically limited than suppressed Douglas-fir saplings. We have sampled suppressed and released saplings of both species for the leaf area, sapwood area, specific conductivity of the basal wood, and anatomy of the basal wood. We are still analyzing data, but it appears that both species release from suppression similarly (if height growth is the metric), and that both species were at least in part hydraulically suppressed. Graduate Students = 3

Impacts
The research on depth of needle attachment is a step in a program that will contribute to making possible more accurate ecosystem models, better estimates of individual tree health, and improved sorting of diverse timber species for drying and treating. This program is identifying the network of functional hydraulic connections within sapwood, important for estimating the heterogeneity of sapwood wood for water transport, the limits of using sapwood area as a predictor of tree productivity and health, and uncovering syndromes of radial sapwood permeability, which relates to both treating and drying. The research on tracheid shape and function will help show the biological limits of wood structure, which is essential for genetic or silvicultural programs that aim to improve wood quality. We ask whether there is a tradeoff in water transport ability in wet vs. dry conditions. If not, then one can select for trees that are capable of having high conductivity (and thus productivity) in good conditions as well as in drought, but if so, then one must be careful not to select for trees with maladaptive traits. Many forests are either overstocked or are grown for non-timber goals but will eventually be re-channeled to production forestry. The research on suppressed hemlock and Douglas-fir will shed light on how to release them by showing the factors that limit their growth when overstory is removed.

Publications

  • Robbins, J.M., B.L. Gartner, and M. Newton. 2005. Effects of pruning on wood density and tracheid length in young Douglas-fir. Wood and Fiber Science 37:xxx. (In press).
  • DeBell, D.S., R. Singleton, B.L. Gartner and D.D. Marshall. 2004. Wood density of young-growth western hemlock: relation to ring age, radial growth, stand density, and site quality. Canadian Journal of Forest Research 34:2433-2442.
  • Domec, J.-C., M.L. Pruyn and B.L. Gartner. 2005. Axial and radial xylem conductivity, water storage and native embolism in young and old-growth ponderosa pine trees. Plant, Cell and Environment. (In press).
  • Johnson, G.R., A. Grotta, B.L. Gartner and G. Downes. 2005. Impact of the foliar pathogen Swiss needle cast on wood quality of Douglas-fir. Canadian Journal of Forest Research. (In press).
  • Domec, J.C., B.L. Gartner, F.C. Meinzer and D. Woodruff. 2004. Transpiration-induced axial and radial tension gradients within the trunk of Douglas-fir trees. Abstract. p. 128 In: Abstracts, Annual Meeting of the Ecological Society of America, August 1-6, Portland, OR.
  • Domec, J.C., B.L. Gartner, F.C. Meinzer and D. Woodruff. 2004. Transpiration-induced axial and radial tension gradients within the trunk of Douglas-fir trees. p. 5 In: Proceedings, 10th Annual WRCCRF Science Conference, June 24-25, Stevenson WA.
  • Domec, J.-C., M.L. Pruyn and B.L. Gartner. 2004. Axial and radial profiles in xylem conductivity, water storage and native embolism in young and old-growth ponderosa pine trees. p. 17 In: Proceedings, International Symposium on Wood Sciences, October 24-29, Montpellier, France.
  • Dunham, S.M., J.C. Domec, B.L. Gartner, F.S. Meinzer and L.M. Ganio. 2004. Errors in extrapolating values of specific conductivity and vulnerability to embolism from branches to boles. Abstract. p. 134 In: Abstracts, Annual Meeting of the Ecological Society of America, August 1-6, Portland, OR.
  • Fallas-Cedeno, L., B.L. Gartner and F.C. Meinzer. 2004. Radial gradients of axial sap flow and xylem tension in four species of hardwoods. Abstract. p. 150 In: Abstracts, Annual Meeting of the Ecological Society of America, August 1-6, Portland, OR.
  • Gartner, B.L. 2004. Effects of Swiss needle cast on basic wood properties. p. 51-56 In: Proceedings, Growing Douglas-fir in the Swiss needle cast zone. Swiss Needle Cast Co-operative, Oregon State University, Corvallis.
  • Gartner, B.L., J.-C. Domec, F.C. Meinzer and D. Woodruff. 2004. Gradients of xylem water tension across Douglas-fir trunks: deducing patterns and causes. p. 23-24 In: Proceedings, International Symposium on Wood Sciences, October 24-29, Montpellier, France.
  • Gartner, B.L., J.R. Moore and B.A. Gardiner. 2004. Gas in stems: abundance and potential consequences for tree biomechanics. Tree Physiology 24:1239-1250.
  • Gartner, B.L. and J. Roy. 2004. Effects of tension wood on water transport and morphology in the evergreen oak Quercus ilex. Abstract. p. 174 In: Abstracts, Annual Meeting of the Ecological Society of America, August 1-6, Portland, OR.
  • Maton, C. and B.L. Gartner. 2004. Longevity of needle-to-stem xylem connections in conifers: patterns and potential causes. p. 41 In: Proceedings, International Symposium on Wood Sciences, October 24-29, Montpellier, France.
  • Renninger, H., A.T. Grotta and B.L. Gartner. 2004. Correlation of latewood formation with leader growth in Douglas-fir saplings. Abstract. p. 423 In: Abstracts, Annual Meeting of the Ecological Society of America, August 1-6, Portland, OR.


Progress 01/01/03 to 12/31/03

Outputs
We finished analysis of the wood of Douglas-fir trees that had been infected with Swiss Needle Cast (SNC) and those that had not. Trees from more heavily infected stands had higher MOE, MOR, wood density and latewood proportion, and lower sapwood moisture content than trees from healthier stands. MFA was not associated with SNC severity. Within stands, needle retention was not associated with MOE or MOR. The increase in latewood proportion in diseased stands appears to be the driving factor behind the increase in strength properties (MOE and MOR). As expected, ring width increased with needle retention. In another study on live 24-year old Douglas-fir, we sought to quantify the axial and radial gradients in xylem tension. Specific conductivity (ks) and sap flux density (Js) were measured at four consecutive depths at the same locations within the sapwood. Because ks is the permeability with a given driving force and Js is the water flux with an unknown driving force, the ratio of Js/ks gives the tension gradient that must have been present. This calculation was made for each of four radial depths. From the differences at these depths, we could also estimate the radial xylem tension gradient. Longitudinal water potential gradients in the outer sapwood were 0.01-0.02 MPa -1, and were 50 percent higher in the outer sapwood than in the inner sapwood. Radial water potential gradients were 0.15-0.25 MPa -1, showing that there is significant resistance to water movement in the radial direction. We began data collection on four hardwood species (red alder, western madrone, hybrid poplar, and bigleaf maple) to make the same types of calculation, but so far have insufficient data. We analyzed growth/wood density relationships in 56 trees in plots representing a wide range of tree and site conditions in northwestern Oregon. Density was highest (0.49 g/cm3) near the pith, then declined to about 0.44 g/cm3 toward the bark in 48 year old trees. There was a very small negative relationship of wood density with growth rate at young tree ages, but no relationship at older ages. Overall, these young-growth hemlock trees are relatively uniform in wood density. The outer wood was more permeable than the inner wood, suggesting that the species does have heartwood, even though there is no discernible color change between the sapwood and heartwood. Other work showed that the tension wood of a diffuse-porous oak had similar conductivity to the normal wood: in this hardwood, the reaction wood does not appear to involve a hydraulic cost to the plant. This contrasts to our previous work in softwoods, in which compression wood had a significant cost in terms of lowered hydraulic conductivity. Species with narrow sapwood had much higher respiratory rates (per unit volume) than did species with wider sapwood in a survey of 10 species (four hardwoods, six softwoods). This research suggests that there is a co-evolved syndrome of sapwood depth and respiration.

Impacts
The Swiss Needle Cast disease actually improves the wood quality, contrary to suggestions made by field foresters. Unfortunately, it reduces growth by a large amount, so this data is useful not as a wood quality strategy, but as an assurance that the wood harvested from these trees will still be useful wood. In these trees, the slower growth rate appears to be associated with the increase in wood quality, through growth rates effect on latewood proportion. This contrasts to research we are conducting in healthy stands in which ring width does not appear to have a consistent relationship with strength properties. The work on axial and radial xylem tension gradients demonstrates the importance of treating the tree bole as a heterogeneous organ for purposes of estimating water movement through trees. The work on western hemlock shows that growth rate has only a weak or no relationship with wood density. This means that the tree can be grown at a variety of growth rates and will still result in a rather uniform product. The research on conductivity in tension wood and on respiration rate as a function of sapwood depth provides basic information on how trees work.

Publications

  • Domec, J.C. and B.L. Gartner. 2003. Relationship between growth rates and xylem hydraulic characteristics in young, mature, and old-growth ponderosa pine trees. Plant, Cell and Environment 26:471-483.
  • Gartner, B.L., J. Roy and R. Huc. 2003. Effects of tension wood on specific conductivity and vulnerability to embolism of Quercus ilex seedlings grown at two atmospheric CO2 concentrations. Tree Physiology 23:387-395.
  • Grotta, A.T., B.L. Gartner and S.R. Radosevich. 2004. Influence of species proportion and timing of establishment on stem quality in mixed red alder/Douglas-fir plantations. Canadian Journal of Forest Research. (In press).
  • Johnson, G.R., B.L. Gartner, A. Kanaskie and D. Maguire. 2003. Influence of Bravo fungicide applications on wood density and moisture content of Swiss-needle cast infected Douglas-fir trees. Forest Ecology and Management 186:339-348.
  • Morrell, J.J., A. Paillard, D. Gnoblei, B.L. Gartner, M.R. Milota and R.G. Rhatigan. 2003. Variations in longitudinal permeability of coastal western hemlock. Wood and Fiber Science 35:397-400.
  • Pruyn, M.L., M.E. Harmon and B.L. Gartner. 2003. Stem respiratory potential in six softwood and four hardwood tree species in the central Cascades of Oregon. Oecologia 137:10-21.
  • Singleton, R., D.S. DeBell and B.L. Gartner. 2003. Effect of extraction on wood density of western hemlock (Tsuga heterophylla (Raf.) Sarg.). Wood and Fiber Science 35:363-369.
  • Taylor, A.M., B.L. Gartner and J.J. Morrell. 2003. Co-incident variations in growth rate and heartwood extractive concentration in Douglas-fir. Forest Ecology and Management 186:257-260.


Progress 01/01/02 to 12/31/02

Outputs
In 15-year old mixed plantings with low proportions of red alder (10 percent) and high Douglas-fir (90 percent), the Douglas-fir trees had a short season of cambial growth, and the trees were highly suppressed. At more equal proportions of the two species, there were fewer adverse wood quality traits. When red-alder planting was delayed by 5 years, there was no effect of density on Douglas-fir until Douglas-fir was at least 75 percent of the stand. At that level, the Douglas-fir trees were shading one another, thereby decreasing the length of the cambial growing season. Ponderosa pine from the Willamette Valley (WV) was compared to that from the Cascade Mountains (CM) to provide information on the WV pine wood quality. WV had much denser wood because the earlywood was denser than the earlywood in the WV, not because of differences in the latewood, the latewood proportion, or the radial growth rate (which was similar in the two regions). Moreover, after the first few rings, the WV wood had a continual increase in density from one growth ring to the next, whereas the CM wood remained at a constant density. The WV trees showed slightly higher resistance to embolism, meaning that their wood could withstand a slightly higher tension on the water column before losing conductivity. Thus, it appears that the WV trees are more drought-adapted than are the CM trees, contrary to expectation, and that there are significant differences in the wood density. In a comparison of wood of Swiss-Needle-Cast infected Douglas-fir trees vs. trees that have not been infected, preliminary results indicate that the variation in modulus of elasticity (MOE) and modulus of rupture (MOR) is best explained by the number of growth rings/cm, rather than by needle retention (how many years the needles stay attached to the tree). After accounting for differences in the number of rings, needle retention did not affect MOE or MOR. Thus, it appears that Swiss needle cast is affecting wood strength through its impact on ring width. Trees from areas with a high degree of infection have narrower rings and stronger, denser wood. Research is ongoing to learn the extent to which a trees health affects the durability of its heartwood. We hypothesize that a tree that has ample resources, such as light, water, and nutrients, will have resources in excess of those needed for growth and maintenance that can be shunted into defensive compounds in the newly formed heartwood. Alternatively, the tree with ample resources will simply produce more material of the same quality as it always made, without having excess materials. Results so far suggest the former in Douglas-fir, in which we examined wood from trees that had been released from competition by a stand thinning 10 years before. Current research is looking at Douglas-fir in more circumstances, and also looking at western redcedar, a species for which heartwood durability has a large impact on the perceived quality, and thus value, of the lumber.

Impacts
The research with Douglas-fir and alder tree mixtures provides information on how sensitive is the production of wood (and its quality) to the local environment of the trees. The work with ponderosa pine gives information to tree growers on how to market their wood. Currently, about 700,000 valley ponderosa pines are planted in the Willamette Valley annually because the trees grow in sites that are not suitable for Douglas-fir. The research on the effect of the needle pathogen on wood quality will help managers estimate the value of their infected forests. Many infected trees are now moribund, and owners of a large inventory of forest in coastal Oregon and Washington need to decide whether to harvest them. If the research on heartwood durability shows that one can cause practically significant boosts in the durability of heartwood by increasing the resources for trees, then we would have two avenues to increase heartwood durability: stand manipulation, and tree breeding for characteristics that alter the use of the resources. If we could then improve heartwood durability, we could have more naturally durable wood, increasing wood's service life, and decreasing the necessity of using environmentally-less friendly preservatives.

Publications

  • Taylor, A.M., B.L. Gartner and J.J. Morrell. 2002. Heartwood formation and natural durability -- A review. Wood and Fiber Science 34:587-611.
  • Grotta, A.T. 2002. Competitive interactions in young coastal Douglas-fir/red alder mixtures: Implications for wood quality. M.S. Thesis. Departments of Wood Science and Engineering and Forest Science. Oregon State University, Corvallis. 109 p.
  • Bouffier, L.A., B.L. Gartner and J.-C. Domec. 2003. Density and hydraulic properties of ponderosa pine trunk wood from the Cascade Mountains vs. the Willamette Valley. Wood and Fiber Science. (Accepted for publication).
  • Cherubini, P., B.L. Gartner, R. Tognetti, O.U. Braker, W. Schoch and J.L. Innes. 2003. Identification, measurement and interpretation of tree rings in woody species from mediterranean climates. Biological Reviews. (Accepted for publication).
  • DeBell, D.S., R. Singleton, C.A. Harrington and B.L. Gartner. 2002. Wood density and fiber length in young Populus stems: Relation to clone, age, growth rate, and pruning. Wood and Fiber Science 36:529-539.
  • Gartner, B.L., R. Aloni, R. Funada, A.N. Lichtfuss-Gautier and F.A. Roig. 2002. Clues for dendrochronology from studies of wood structure and function. Dendrochronologia 20: 53-61.
  • Singleton, R., D.S. DeBell, D.D. Marshall and B.L. Gartner. 2004. Eccentricity and fluting in young-growth western hemlock. Western Journal of Forestry. (In press).


Progress 01/01/01 to 12/31/01

Outputs
We finished field work for a project looking at how various mixtures of Douglas-fir and alder affect the timing and quality of wood produced in Douglas-fir and its branch characteristics. Samples are now being analyzed under the microscope to finish collecting the data. A masters thesis is ongoing on this project. Research began to compare the wood properties of ponderosa pine from the Willamette Valley to that from the Cascade Mountains. The project is being conducted by a student intern. Preliminary results showed that the wood from the valley is much denser than the wood from the Cascades. In most species, if there is a difference in wood density, it is caused by the proportion of latewood. However, in this case, the proportion of latewood was the same in both regions (four sites in each region), and both the earlywood and latewood were denser from the valley than the Cascades. Other research we conducted in 2001 showed that earlywood and latewood have different hydraulic properties in Douglas-fir. Earlywood is more conductive when the plant has plenty of water, but it loses its conductivity quickly during drought relative to latewood. Given that the two populations of ponderosa pine differ in their earlywood characteristics, it would be interesting to learn how this difference affects water transport when wet or drought-stressed. In research with Swiss-Needle-Cast infected trees vs. trees that have been sprayed with a fungicide, we found that the wood differs in density only because latewood proportion differs between the two types of trees. That is, both earlywood density and latewood density are unchanged; the disease simply increased the proportion of latewood, which is expected, given that the trees have a reduced needle area and so do not need much water transport ability. However, in about three-fourths of the studies surveyed for Douglas-fir, wider growth rings have lower wood density. Given that the sprayed trees had much wider growth rings, the study suggests that the disease does actually decrease the density of the wood over what it would ordinarily be, given its slow growth rate. We are now reviewing the literature to try to better understand the growth rate/wood density relationship.

Impacts
The research with Douglas-fir and alder tree mixtures will give us more information on how sensitive is the production of wood (and its quality) to the local environment of the trees. The work with ponderosa pine will provide information to tree growers on whether the wood of the trees in the valley appears to be good for utilization. Currently, about 700,000 valley ponderosa pines are planted in the Willamette Valley annually because the trees grow in sites that are not suitable for Douglas-fir. Until this research, there were no data on the quality of the wood. The research on the effect of the needle pathogen on wood quality will help managers estimate the value of their infected forests. Many infected trees are now moribund, and owners of a large inventory forest in coastal Oregon and Washington need to decide whether to harvest them. We may also be able to find techniques to view previous outbreaks of the disease through its signature in the wood, and if so, to estimate how long the outbreaks last and whether trees can return to full vigor.

Publications

  • Spicer, R. and B.L. Gartner. 2001. The effects of cambial age and position within the stem on specific conductivity in Douglas-fir (Pseudotsuga menziesii) sapwood. Trees 15:222-229.
  • Domec, J.C. and B.L. Gartner. 2002 Age- and position-related changes in hydraulic versus mechanical dysfunction of xylem: Inferring the design criteria for Douglas-fir wood structure. Tree Physiology 22:91-104.
  • Pruyn, M.L., B.L. Gartner and M.E. Harmon. 2002. Respiratory potential in sapwood of old versus young ponderosa pine trees in the Pacific Northwest. Tree Physiology 22:105-116.
  • Wilson, B.F. and B.L. Gartner. 2002. Effects of stem girdling in conifers on apical control of branches, growth allocation and air in wood. Tree Physiology.
  • DeBell, D.S., B.L. Gartner and C. Keyes. 2001. Wood density of Eucalyptus saligna grown in Hawaiian plantations: Effects of silvicultural practices and relation to growth rate. Australian Forestry 64:106-110.
  • Domec, J.C. and B.L. Gartner. 2001. Cavitation and water storage capacity in bole xylem segments of mature and young Douglas-fir trees. Trees 15:204-214.
  • Gartner, B.L., E.M. North, G.R. Johnson and R. Singleton. 2002. Wood density in relation to live crown position in 34-year old trees of Douglas-fir (Pseudotsuga menziesii). Canadian Journal of Forest Research. (Accepted for publication).
  • Spicer, R. and B.L. Gartner. 2002. Compression wood has a minimal impact on the water relations of Douglas-fir (Pseudotsuga menziesii) seedlings despite a large effect on aboveground shoot hydraulic properties. New Phytologist. (In Press).
  • Pruyn, M.L., B.L. Gartner and M.E. Harmon. 2002. Within-stem variation of respiration in Pseudotsuga menziesii (Douglas-fir) trees. New Phytologist. (Accepted for publication).
  • Gartner, B.L. 2002. Sapwood and inner bark quantities in relation to leaf area and wood density in 34-year old Douglas-fir. IAWA Journal. (Accepted for publication).


Progress 01/01/00 to 12/31/00

Outputs
1) We related the heartwood durability to the leaf area per sapwood area of the tree. We had reasoned that higher leaf area per sapwood area would have more carbon-based resources per new heartwood cell and would deposit a higher concentration of heartwood defenses. However, we found no relationship between durability and the leaf area per sapwood area (Gartner et al. 2000). 2) In other work, we've compared the ability of wood from different parts of Douglas-fir and ponderosa pine trees to conduct water during drought. So far, we've found that in Douglas-fir, the wood from the top of the tree has lower water storage capacity, lower permeability, and lower propensity to lose conductive capacity during drought than wood from lower in the tree. We have proposed new laboratory and computational methods for comparing the vulnerability of plant parts to lose conductive capacity during drought, and a new method for calculating water storage capacity (Domec and Gartner in press). 3) A study of water transport within stems of Douglas-fir has shown that sapwood is not uniform in its permeability: outer sapwood is more permeable than inner sapwood, and wood at the base of the crown is more permeable than that at the tree base or tree tip (Spicer and Gartner submitted). This research has also shown that the patterns of permeability must result from two different processes: cambial maturation (wood farther from the pith and higher in the tree has different anatomy than wood nearer the pith or lower in the tree) and xylem aging (sapwood that has been functional for many years has accumulated blockages and injuries that decrease its transport ability, Spicer and Gartner submitted). 4) Other research has also challenged a rule-of-thumb that wood produced within the crown of conifers has juvenile wood characteristics and wood produced below the crown has mature wood characteristics. Our research shows no significant effect of crown position on wood specific gravity components (earlywood density, latewood density, and percent latewood), and show that most of the variance is the pith-to-bark variation within the disks themselves (Gartner et al. submitted). 5) We have begun research on the wood properties that come from trees infected with the pathogen responsible for Swiss needle cast in Douglas-fir. This pathogen causes the trees to lose their ability to regulate water, decrease photosynthetic uptake, and lose most of their needles. The effect of the pathogen on the wood is unknown, but it is likely that the wood will have lower density, much smaller growth rings, and narrower and drier sapwood. We have initiated experiments to compare wood density components, moisture content, and leaf area/sapwood area of trees with severe Swiss Needle Cast and those with less severe Swiss Needle Cast. 6) In a study of eucalyptus trees, we found no effect of growth rate on wood density, regardless of whether growth rate was stimulated by fertilizer, increased spacing, or by interplanting with a nitrogen-fixing tree species. Individuals with more rapid growth had more uniform wood density patterns across the radii (DeBell et al 2001).

Impacts
New techniques proposed for measuring and computing hydraulic characteristics of the wood of living trees will help advance the study of water movement in woody plants, an area that has suffered from lack of methodologies to make vulnerability measurements in large members such as trunks, and to compare water storage among plant parts that vary in their wood densities. Research on the heterogeneity of xylem for water transport suggests that a reevaluation is needed of rules-of-thumb that rely on sapwood area/leaf ratios and the underlying assumption that all sapwood is equally effective at transporting water. The algorithm that leaf area can be estimated from sapwood area is commonly used by foresters and ecosystem ecologists to judge tree vigor. Research on the effect of crown position on wood quality is also important to forest resource modelers who assume that the wood in the crown is low-value juvenile wood and that wood below that point is high value mature wood. The research on the effect of the needle pathogen on wood quality will help managers estimate the value of their infected forests. We are searching for new techniques to view previous outbreaks of the disease through its signature in the wood, and if so, to estimate how long the outbreaks last and whether trees can return to full vigor. The eucalyptus study showed that diameter growth could be increased substantially without decreasing wood density and that rapid growth resulted in wood with a more uniform increase in density form pith to bark.

Publications

  • DeBell, D.S., B.L. Gartner and C. Keyes. 2001. Wood density of Eucalyptus saligna grown in Hawaiian plantations: Effects of silvicultural practices and relation to growth rate. Australian Forestry. (In Press).
  • Domec, J.-C. and B. L. Gartner. 2001. Cavitation and water storage capacity in bole xylem segments of mature and young Douglas-fir trees. Trees. (In Press).
  • Gartner, B.L., D.C. Baker and R. Spicer. 2000. Distribution and vitality of xylem rays in relation to tree leaf area in Douglas-fir. IAWA J. 21: 389-401.


Progress 01/01/99 to 12/31/99

Outputs
Many young stands of Douglas-fir are showing an undesirable characteristic of stem form, sinuosity, in which the stem zigzags from side to side rather than growing erect. Silviculturists questioned whether the leader sinuosity would increase or decline as trees grew, and wood scientists questioned how wide were the defective cores in these sinuous trees. We found that trees with highly sinuous leaders at age 12 were more likely to be sinuous in other years, and developed more slope of grain defect (about 15 percent of log volume) than less sinuous trees. However, they did not differ in the size of the pith-containing core. The size of the pith deviations (radial distance from center-line) remained constant up the stem tree. The maximum diameter of the defective core (that which contains pith or has slope of grain greater than 7 degrees) in highly sinuous trees was about 5 cm or 9 cm, respectively. These results suggest that from a wood-quality perspective, silviculturists need only remove the highly sinuous trees from the stands, and can ignore sinuosity on other trees. To learn whether the stems and roots of different genotypes differed in their ability to function during drought, we grew known genetic material of Douglas-fir in common gardens for two years. We assessed vulnerability of the tissues to cavitation; i.e., loss of hydraulic conductivity at a given degree of drought. The most vulnerable population was from the coastal wet site, followed by the interior wet site, and then the two dry sites (coastal and interior). Root xylem was more vulnerable to drought than stem xylem. This research shows that there is hydraulic adaptation of Douglas-fir populations, and suggests that there are wood anatomical differences responsible for these results. Therefore, the wood from the four sites must be different in ways that could influence treatability or other aspects of Douglas-fir wood. We related the natural durability of heartwood to the vertical and radial position of that heartwood in young Douglas-fir trees. We found no significant relationship. This result suggests that for young stands, the heartwood durability can be regarded as homogenous. We also related the heartwood durability to the leaf area per sapwood area of the tree. We had reasoned that higher leaf area per sapwood area would have more carbon-based resources per new heartwood cell and would deposit a higher concentration of heartwood defenses. However, we found no relationship between durability and the leaf area per sapwood area. These results taken together suggest that young Douglas-fir is robust with respect to the effect of silvicultural regimes on heartwood durability. In contrast, we found large effects of radial and vertical position on natural durability of older western redcedar samples. The first-produced heartwood, whether one looks near the pith at the bottom of the tree or near the pith at the top of the tree, has little natural durability, but it increases about linearly with age. These results suggest that western redcedar harvested at short rotation ages will have less durable heartwood than trees harvested at older ages.

Impacts
Humans rely on a variety of characteristics for their different uses of wood, such as straightness of grain, natural durability, treatability, and appropriate density and fiber length. Specific understanding of how the tree uses those characteristics will help us better predict the spatial patterns of their occurrence, as well as help us suggest silvicultural regimes and tree-breeding strategies which will improve wood quality for a given end-use.

Publications

  • DeBell, J.D., Gartner, B.L. and Morrell, J.J. 1999. Within-stem variation in tropolone content and decay resistance of western redcedar. Forest Science 45:108-114.
  • Gartner, B.L., Morrell, J.J., Freitag, C.M. and Spicer, R. 1999. Heartwood decay resistance by vertical and radial position in Douglas-fir trees from a young stand. Canadian Journal of Forest Research 29:1993-1996.
  • Kavanagh, K.L., Bond, B.J., Aitken, S.N., Gartner, B.L. and Knowe, S. 1999. Root and shoot vulnerability to xylem cavitation in four populations of Douglas-fir seedlings. Tree Physiology 19:31-37.
  • Spicer, R., Darbyshire, R. and Gartner, B.L. 2000. Sinuous stem growth in a Douglas-fir (Pseudotsuga menziesii) plantation: Growth patterns and effects on wood quality. Canadian Journal of Forest Research. (Accepted for publication).


Progress 01/01/98 to 12/31/98

Outputs
The upper and lower halves of branches have different types of mechanical tissues. Whereas the main role of these tissues is presumed to be mechanical, they also affect water transport and wood utilization. The lower side of Douglas-fir (Pseudotsuga menziesii) branches has lower specific conductivity than the upper side, due in part to narrower tracheids. If one removes the tip of a tree, a side-branch will re-orient to become the new leader. In so doing, it produces even more of the special type of wood found on the underside of branches (compression wood). After two growing seasons, this re-oriented branch has the same specific conductivity as a normal branch, but has much less leaf area per stem cross-sectional area, and in this manner it has the ability to deliver water to the foliage at an intermediate rate between a normal branch and a normal leader. Fiber length is an important characteristic for pulp used for making paper. When cottonwood (Populus) is grown at extremely different growth rates there is no effect on fiber length for growth rings 2-6, but in growth ring 7, trees with faster growth had longer fibers. All trees produce longer fibers in each successive year of growth. Because trees that grow the fastest have the greatest proportion of their wood in outer growth rings (the rings with the longest fibers), the fastest-grown trees actually have the highest average fiber length. Many young stands of Douglas-fir are showing an undersirable characteristic of stem form, sinuousity, in which the stem zig-zags from direction to direction rather than growing erect. It is unknown whether these trees will have less or more sinuosity from one year 92s growth to the next in the vertical direction, and it is also unknown how wide is the tree 92s defective core. We are currently analyzing results on 8 trees in each of four categories: highly, moderately, minimally, and non-sinuous when their eleventh node was studied in 1984. So far we conclude that the trees that were the most sinuous in 1984 are still the most sinuous. The defective core (with slope of grain greater than 7 degrees) is largest in the group that was highly sinuous in 1984.

Impacts
(N/A)

Publications

  • DeBell, J.D., B.L. Gartner and DeBell, D.S. 1998. Fiber length in young hybrid Populus stems grown at extremely different rates. Canadian Journal of Forest Research 28:603-608.
  • Morrell, J.J. and Gartner, B.L. 1998. Wood as a material. p. 1-14 In: Forest Products Biotechnology. Bruce, A. and Palfreyman, J.W., eds. Taynor & Francis, London.
  • Spicer, R. and Gartner, B.L. 1998 Hydraulic properties of Douglas-fir (Pseudotsugna menziesii) branches and branch halves with reference to compression wood. Tree Physiology 19:777-784.


Progress 01/01/97 to 12/31/97

Outputs
Research on growth strains (strains that develop as the wood cells mature near the outer sapwood) showed that boles have much higher strains than do non-structural roots in two coniferous and two hardwood species. This observations sheds light on the evolution of growth strains (which cause defect in both logs and during lumber processing), suggesting that the strains have evolved in response to the mechanical demand on the plant part. Research on within-plant variation of xylem anatomy showed very few changes from pith to bark in proportion of different cell types and specific gravity for the diffuse-porous species (red alder) but very large changes for the ring-porous species (Oregon white oak). Comparing cottonwood (Populus) trees with extremely different growth rates, the outer (seventh) growth ring showed a positive correlation between growth rate and fiber length, an important wood quality characteristic for paper manufacture. Western redcedar often is used for structural lumber in situations where decay-resistance is important. However, there are reports that second-growth western redcedar, which is the resource most harvested now, is more prone to decay than is the old growth. Ongoing research confirms this observation, showing that the heartwood made at older ages has higher decay resistance and that any silvicultural treatments that affect the size of the heartwood core at different ages will affect the overall decay resistance of the lumber.

Impacts
(N/A)

Publications

  • DEBELL, J.D. and GARTNER, B.L. 1997. Stem characteristics on the lower log of 35-year-old western redcedar grown at several spacings. Western Journal of Applied Forestry 12:9-15.
  • DEBELL, J.D., GARTNER, B.L. and DEBELL, D.S. 1998. Fiber length in young hybrid Populus stems grown at extremely different rates. Canadian Journal of Forest Research. (Accept for pub).
  • DEBELL, J.D., MORRELL, J.J. and GARTNER, B.L. 1997. Tropolone content of increment cores as an indicator of decay resistance in western redcedar. Wood and Fiber Science 29:364-369.
  • GARTNER, B.L. 1996. Does photosynthetic bark have a role in the production of core vs. outer wood? Wood and Fiber Science 28:53-61.
  • GARTNER, B.L. 1997. Trees have higher longitudinal growth strains in their stems than in their roots. International Journal of Plant
  • GARTNER, B.L., LEI, H. and MILOTA, M.R. 1997. Variation in the anatomy and specific gravity of wood within and between trees of red alder (Alnus rubra Bong.). Wood and Fiber Science 29:10-20.
  • LEI, H., GARTNER, B.L. and MILOTA, M.R. 1997. Effect of growth rate on the anatomy, specific gravity, and bending properties of wood from 7-year-old red alder (Alnus rubra). Canadian Journal of Forest
  • SPICER, R. 1997. Hydraulic properties of compression wood in branches and reoriented shoots of Douglas-fir (Pseudotsuga menziesii). Dept. of of Forest Products, Oregon State Univ., Corvallis. 94 pp.


Progress 01/01/96 to 12/30/96

Outputs
Tension wood is generally regarded as unsatisfactory for forest products becauseof its excessive longitudinal shrinkage and difficult machinability. A study in red alder found that when the stems lean at angles above 26 degrees, the stem develops tension wood. At angles of 6 to 26 degrees, tension wood develops in some of the stems, and at angles below 6 degrees, no tension wood develops. The trees are able to develop large growth strains in the absence of tension wood at angles above 6 degrees, although most of the large growth strains are associated with tension wood. In a wood quality study of Oregon white oak, we found that most anatomical characters did not differ significantly between breast height and 4.4 m. In the radial direction there were significant differences in fiber length; proportion of fiber, vessel, and axial parenchyma; and specific gravity. A study of wood quality in young red alder trees showed that properties remained remarkably uniform across growth rates from 2.0 to 9.3 mm per year of radial growth. Growth rate had no effect on specific gravity, MOE or MOR in bending, fiber diameter, or the proportion of the growth ring that was fiber or vessel. Fiber length, vessel diameter, and ray proportion were positively correlated with growth rate.

Impacts
(N/A)

Publications

  • LEI, H., MILOTA, M.R. and GARTNER, B.L. 1996. Between- and within-tree variationin the anatomy and specific gravity of wood in Oregon white oak (Quercus garryana Dougl.) IAWA Journal 17:445-461.
  • WILSON, B.R. and GARTNER, B.L. 1996. Lean in red alder (Alnus rubra Bong.): Growth, stress, tension wood, and righting response. Canadian Journal of Forest Research 26:1951-1956.
  • GARTNER, B.L., H. LEI, and M.R. MILOTA. 1997. Variation in the anatomy and specific gravity of wood within and between trees of red alder (Alnus rubra Bong.) (In Press).


Progress 01/01/95 to 12/30/95

Outputs
Research on the effects of cambial age on wood properties of two native hardwoods showed that cell length increases greatly from pith to bark in both species, that red alder had little variation in other anatomical and physical properties tested, and that Oregon white oak had a large decrease in specific gravity from pith to bark. Research was started on the vertical and horizontal profiles of physiological and structural properties within stems in 29-year old Douglas-firs at two stand densities including permeability of sapwood, its decay resistance, longevity of nuclei in the ray parenchyma, and xylem anatomy. Live Douglas-fir has the same sapwood permeability regardless of stand density, even though trees in the thinned stand had twice the leaf area/sapwood area. This suggests that Douglas-fir does not base its sapwood quantity on the need for water transport. A survey of four native species, showed that roots had much lower growth strains than trunks, suggesting that higher strains in stems are adaptations for the mechanical role of the xylem. In a study of red alder research showed that lean angle at which elevated growth stresses and tension wood develop are both factors that affect wood properties.

Impacts
(N/A)

Publications

  • GARTNER, B.L. 1996. Does photosynthetic bark have a role in the production of core vs. outer wood Wood and Fiber Science 28(1):(In press).
  • LEI, H. 1995. The effects of growth rate and cambial age on wood properties of red alder (Alnus rubra Bong.) and Oregon white oak (Quercus garryana Dougl.). Ph.D. Dissertation. Oregon State Univ., Corvallis. 192p.