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PLEASE NOTE: Publications listed in this catalog are available for viewing, printing, and downloading from this site. Just click on the "View and Print this Publication Now" link under the abstract. Please send e-mail to rdm@srs.fs.usda.gov if you have any problems viewing or printing these publications.
The seven publications that are published by the Southern Research Station are also available in hard copy through the mail. To order Station publications in hard copy, print the Publications Order Form that is at the "Order This Publication" link. You may request more than one title per form, up to two copies of the same title. The number in parentheses at the end of the publication description, is the number to circle on the form; i.e., to order: Vissage, John S. "Forest statistics for Southwest-South Alabama, 1999" you would circle 21.
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Managing Forests—Maximizing Carbon Storage Atmospheric CO2 (an important "greenhouse" gas) is rising at a historically rapid pace, mainly due to global conversion of forests to agriculture and urban landscapes, combined with increasing quantities of CO2 emitted from burning fossil fuels. There is advancing theoretical and empirical evidence that increasing greenhouse gases may be altering the world's climate. As such, there has been considerable international deliberation, both political and scientific, on potential avenues to reduce net carbon emissions. While many short-term studies have shown atmospheric carbon dioxide increases tree growth, an article co-authored by three Southern Research Station scientists takes a longer view. Soil Fertility Limits Carbon Sequestration by Forest Ecosystems in CO2-enriched Atmosphere, published in the May 24 issue of Nature, indicates that along a gradient of decreasing site fertility, nutrient amendments (nitrogen) would become increasingly necessary if forested ecosystems are to help reduce the rate at which atmospheric carbon dioxide concentrations increase. The study is part of the effort to understand the relationship between forests, which often are limited to sites with low nutrient soils, and carbon sequestration, in order to estimate current and future global carbon budgets. Lead author is Ram Oren, School of the Environment and Earth Sciences, Duke University. Ten co-authors include Southern Research Station scientists Kurt Johnsen and Chris Maier of Research Triangle Park, and Steve McNulty of Raleigh. Johnsen serves as project leader for the Biological Foundations of Southern Forest Productivity and Sustainability research unit. Maier performs research as a biologist in the RTP project. Steve McNulty is an ecologist with the Southern Global Change Program. Ram Oren's co-principal investigator is David Ellsworth, School of Natural Resources, University of Michigan, Ann Arbor, and the Brookhaven National Laboratory in Upton, N.Y. In addition to Forest Service scientists Johnsen, Maier, and McNulty, other co-authors include Nathan Phillips, Department of Geography, Boston University; Karina Schäfer, Heather McCarthy, Brent Ewers, and Gabriel Katul, Duke; and George Hendrey of Brookhaven, who designed and engineered the Duke Forest site of the experiment. The experiments reported in Nature showed that without additional nutrients, initial growth increases of mature loblolly pine trees leveled off after the first three years of exposure. In addition to nutrient limitations, growth responses were also sensitive to the availability of soil moisture. The presence of elevated levels of carbon dioxide alone, which is occurring due to global industrialization and land use changes, may not result in a long-term increase in the rate of tree growth. However, the results also suggest that forest fertilization, already a practice in southern pine plantations, might become even more beneficial in a high carbon dioxide world. In light of discussions of the findings presented in Soil Fertility Limits Carbon Sequestration by Forest Ecosystems in CO2-enriched Atmosphere, Johnsen, Oren, McNulty, and Maier chose to address the prevailing misconception that forests will not be important in absorbing CO2 from the atmosphere and thus will not help to mitigate climate change. This ignores the fact that carbon absorption by the pine trees from both the present-day atmosphere and from the manufactured atmosphere representing the future was substantial. The authors did find that the CO2-absorbing capacity of the experimental forests was not increased much from what it is in the present by the higher CO2 that simulates future conditions. So the unfortunate conclusion drawn by some is that contrary to expectations of many scientists and policy-makers, current forests on low fertility soils, represented by this study, will not take up more CO2 in the future than it does today. The authors concluded that nutritional and water limitations to growth must be considered in computer models that predict forest responses to elevated CO2. However, this work should not be used to minimize the importance of forests in the global carbon budget or to refute the potential value of managed forests to reduce overall CO2 net emissions. This is especially important since results from these models can be the basis of some policy decisions. We use the Southern United States, the region where the study was done, as one example of the potential of forests to sequester atmospheric carbon. Carbon sequestration in southern pine forests continues to increase with improvements in forest management. The nearly four-fold increase in pine productivity over the last half-century is the result of genetic improvement, site preparation, and other management activities. Larger trees over time are a consequence of greater amounts of carbon absorbed from the atmosphere. When southern pine forests are eventually harvested, various forest products such as conventional lumber, fiberboard, and paper products have "life-spans" during which time the carbon in them is kept out of the atmosphere. Remaining parts of harvested trees like taproots can be slow to decay, thereby further retaining carbon out of the atmosphere. Although in an associated study soil carbon was not shown to increase strictly due to elevated CO2 over a three-year period, other longer-term studies have shown that productive forests do increase soil carbon, particularly if they are established on sites that were degraded by past agriculture practices. Furthermore, in the Southern United States, converting the over 15 million acres of marginal agriculture land to pine forests could produce a 20-fold increase in carbon sequestration on those sites. So planting forests is not as futile as has been stated based on misinterpretation. The opposite trend, the conversion of forests to agriculture and urban landscape, releases large amounts of carbon into the atmosphere. Thus, higher productivity and more forest acreage in the Southern States could increase carbon sequestration to account for an additional 5 percent of the CO2 produced by the United States annually, and conservation of forests, both regionally and globally, is imperative for stemming increasing atmospheric CO2. Although not a panacea, this represents an important and realistic tool for mitigating increasing atmospheric CO2 concentrations. Collaborative sources funded this study: the USDA Forest Service; the U.S. Department of Energy, Office of Health and Environmental Health and Environmental Research; the National Institute for Global Environmental Change, Southeast Regional Center at the University of Alabama; and the National Science Foundation's Multi-user Instrument Program. The Summer 2001 issue of Compass includes several articles about forest management and carbon dioxide: Booker, Fitzgerald L.; Maier, Christopher A. 2001. Atmospheric carbon dioxide, irrigation, and fertilization effects on phenolic and nitrogen concentrations in loblolly pine (Pinus taeda) needles. Tree Physiology. 21: 609-616. (1) Johnsen, Kurt H.; Wear, D.; Oren, R.; and others. 2001. Carbon sequestration and southern pine forests. Journal of Forestry. 99(4): 14-21. (4) Oren, Ram; Ellsworth, David S.; Johnsen, Kurt H.; and others. 2001. Soil fertility limits carbon sequestration by forest ecosystems in a CO2–enriched atmosphere. Nature. 411: 469-472. (16) Dating Stream Sediments Government agencies responsible for water quality, as well as anyone whose drinking water, recreational activities, or economic livelihood depends on stream health, demonstrate increasing interest in determining whether stream sediment at a particular location is the result of recent terrestrial erosion or reworking of sediment already in the drainage system. Jonathan D. Phillips, University of Kentucky, and Daniel A. Marion, Southern Research Station, have developed new and more affordable field and laboratory techniques to address this question. In Residence Times of Alluvium in an East Texas Stream as Indicated by Sediment Color, Phillips, a University of Kentucky geographer, and Marion, a research hydrologist in Oxford, MS, use sediment residence times to discriminate between "new" sediment caused by recent erosion outside a stream and "old" sediment that was eroded in the past and stored within a stream. The Environmental Protection Agency is charged with developing watershed goals for areas identified as being in an impaired state. The Total Maximum Daily Load (TMDL) sets the allowable amount of sediment moving through a stream. Marion says, "If monitoring reveals a TMDL has been exceeded, the next question becomes, ‘Whose sediment is it?’" One path to finding the answer could be determining the sediment’s age. Phillips and Marion show that soil color can indicate the length of time sediment has been stored at a sampled site. Hypothetically, if these methods revealed soil characteristics specific to new sediment, then the focus of regulatory agencies could shift to determining the cause of erosion. The authors caution that their methods are only applicable where soils contain a large amount of iron oxides (a characteristic of many soils in the South). They also state that soil color indicators are most useful when combined with other methods. The depth of sediment covering the root collar of trees and root growth patterns can reveal physical history before and after flooding. Buried soil horizons, the presence of invasive tree species, and the age of buried trees can provide additional evidence to more precisely date sediment or demonstrate changes in sedimentation rates. Dan Marion, a scientist in the Managing Upland Forest Ecosystems in the Midsouth research unit, headed by Jim Guldin, began working with Jonathan Phillips when the geographer was with Texas A&M University. Phillips’ ideas about geochemical dating and soil characteristics formed the basis for their research on stream sedimentation in Loco Bayou, a tributary of the Angelina River. Using the research methods described in Residence Times of Alluvium in an East Texas Stream as Indicated by Sediment Color could cost a couple of thousand dollars. In contrast, using radionuclide methods would cost several times as much. Phillips and Marion plan to continue their sediment dating research. Their next study will focus on more quantitative and rigorous analysis of iron reduction in soils so as to better refine sediment residence times. To receive a copy of Residence Times of Alluvium in an East Texas Stream as Indicated by Sediment Color, circle publication 8 on the request card. Station News Conferences and Workshops The 8th Workshop on Seedling Physiology and Growth Problems in Oak Plantings takes place September 9-12 in Hiawassee, GA. The USDA Forest Service, Southern Research Station, Institute of Tree Root Biology, and the Southern Region, join the Georgia Forestry Commission to sponsor this workshop. The three-day event covers regeneration involving silvicultural manipulation, physiological attributes, tree improvement, and insects and disease problems. Private and industrial landowners, nursery owners, land managers, and scientists will find topics to interest them. One session will feature a demonstration on how to establish a 2 acre oak stand. The meeting will include equal sessions of oral presentations, discussions, and field trips. The Hiawassee-Blairsville area of North Georgia straddles the Appalachian Trail. The forests in this region are experiencing transition, with many oak species declining as faster growing, more shade-tolerant species begin to dominate the higher quality sites. Workshop planners say oak biological attributes may be the essential element needed to successfully regenerate the many important species of oak. For more information about the 8th Workshop on Seedling Physiology and Growth Problems in Oak Plantings, please contact Paul P. Kormanik, Institute of Tree Root Biology, 706-559-4288; Susana Sung, 706-559-4289, ssung@fs.fed.us; or William Otrosina, 706-559-4295, wotrosina@fs.fed.us. That place where urban lands meet and interact with rural lands defines the wildland-urban interface (WUI). To understand the meaning of the term, consider attending the Wildland-Urban Interface: Sustaining Forests in a Changing Landscape conference in Gainesville, FL, November 5-8. A field trip on the first day will introduce participants to WUI issues in Florida. Forestry and natural resource managers and scientists, arborists and horticulturists, industry and consulting foresters, and Federal, State, regional, county, and city planners and policymakers can benefit from attending the conference. Sponsors include the USDA Forest Service, Southern Research Station and Southern Region, the University of Florida, and the Southern Group of State Foresters. For more information, contact Mary L. Duryea at 352-846-0896 or mlduryea@ufl.edu, or Susan W. Vince at 352-846-0886 or svince@ufl.edu. For information on the Web, visit http://www.conference.ifas.ufl.edu/urban . Southern forests provide immeasurable benefits for our country. This diverse region supports rich ecological, economic, and cultural systems. Plan now to attend the Southern Forest Science Conference in Atlanta on November 26-28. Sponsored by southern forest science and management communities, this conference will celebrate past accomplishments and create a vision for the future of southern forestry research and management. Scientists, managers, owners, and users of southern forests share a common desire to sustain and improve these forests and the benefits they provide. The USDA Forest Service, Southern Research Station and Southern Region co-sponsor the Southern Forest Science Conference. For more information, contact Hermann Gucinski or Nancy Walters, Southern Research Station, 828-257-4302, or visit http://www.southernforestscience.net. Accomplishments and Awards Cassandra Johnson recently graduated from the University of Georgia with a Ph.D. in sociology. Cassandra, a social scientist in Ken Cordell’s unit in Athens, GA, focuses on environmental sociology and natural resources. Johnson researches attitudes about outdoor recreation and leisure, environmental justice, and ethnicity. Congratulations, Dr. Johnson! Southern Station Director Pete Roussopoulos received the 2000 Presidential Rank Award of Meritorious Executive. Winners of this prestigious award have demonstrated ability to lead a Government Agency that delivers great service, fosters partnerships and community solutions to achieve results, and continuously pushes itself to get the job done more effectively and efficiently. Only one of two Senior Executives in the Forest Service to receive this award, Pete was recognized for outstanding service in natural resources and the environment. Pete became Director of the Southeastern Forest Experiment Station in 1992. In 1995 he became Director for the combined Southern Research Station, responsible for Forest Service Research and Development throughout the 13 Southern States. We are proud of you, Pete, and the work you encourage us to accomplish. The Southern Appalachian Mountains and the Biosphere, known as SAMAB, honored Nancy Herbert, Southern Research Station Assistant Director—Mountains with the Hinote Award. Nancy earned this honor for her dedication during her two terms as vice president of the SAMAB executive committee and for stepping up to fill the vacated chairperson’s position. The U.S. Department of Agriculture recognized two Southern Research Station scientists with the USDA Honor Award. James H. Miller is a research ecologist and team leader in Charlie McMahon’s silviculture project, located on the campus of Auburn University in Alabama. The USDA honors Jim’s leadership in research and outreach to further plant conservation and nonnative plant management for sustaining productivity and biodiversity in the forests of the Southeastern United States. Hermann Gucinski, Assistant Director for Research—Global Change, received the USDA Honor Award as a member of the intra-agency Climate Change Negotiations Analytic Support Team. The team made significant contributions to improving the Kyoto Protocol through the consideration of forest, crop, and grazing land management. In addition to overseeing the Southern Global Change research work unit in Raleigh, NC, Hermann oversees the Forested Wetlands and Bottomland Hardwoods research work units in South Carolina and Mississippi and other related Southern Research Station work. The Chief of the Forest Service Honor Award for Distinguished and Superior Science was bestowed on Ken Cordell, project leader in Athens, GA, located on the University of Georgia campus. Ken has been a champion for understanding visitor preferences for natural resources experiences on public lands for four decades. Cordell received the award to honor his national and international science leadership in developing methods for conducting broad-scale assessments of long-term trends in outdoor recreation, wilderness, and American demographics. Government agencies and private organizations use these assessments extensively in planning, policy, research, and education. Wayne T. Swank, research ecologist emeritus at the Coweeta Hydrological Laboratory; Robert C. Thatcher, former Southeastern Forest Experiment Station assistant director for research in Georgia and Florida; and Charles C. Van Sickle, former assistant director for research in the Carolinas and Virginia, Southeastern Forest Experiment Station and Southern Station, received the honorable title of Fellow of the Society of American Foresters (SAF). This organization awards the honor of Fellow based on an individual’s strong continuing commitment through direct SAF volunteer activities and exemplary action, sustained leadership, and advancement of the forestry profession at the local, regional, national, or international level. An applicant for Fellow must be nominated by 30 peers and voted on by the SAF membership. Familiar Faces in New Places Congratulations to John Kelly, promoted to assistant director for Inventory and Monitoring. John oversees the research and field components of Forest Health Monitoring and Forest Inventory and Analysis (FIA), and the research units for forest products and forest operations. John began his Forest Service career in 1985 as a research forester in the FIA project in Starkville, MS. John initiated the process of changing from flat data files for each State to a regional relational database. John became project leader in 1994, and moved to Asheville in 1996 as Inventory and Monitoring program manager for the Southern Research Station. Under John’s leadership, the Southern Station has established an east-wide database. We are in the processing of migrating to the national FIA database. Rob Doudrick moves to the Forest Service’s Washington Office to become staff assistant to the budget coordinator for Research and Development. Rob has served as the Southern Research Station’s Assistant Director for Planning and Applications since 1998. He has led the Station’s efforts to increase outreach efforts to underserved customers. Doudrick began his Forest Service career in Gulfport, MS, as a post-doctoral plant pathology student. The research unit moved to Saucier—which borders on Success—where Rob became project leader in 1989. During the last year, Rob has been a Legislative Fellow with Congressman Charles Taylor’s office. We will miss you, Rob, but we will definitely work to stay on your radar screen! Congratulations to you and your family as you travel further. Pauline Spaine joins Congressman Taylor’s office as legislative assistant for environmental issues. Paula is a plant pathologist in Kerry Britton’s Insects and Diseases of Southern Forests unit in Athens, GA. Bruce Jewell has joined the Southern Research Station as Assistant Director for Research. Bruce oversees the research work units involved with southern pines. Bruce was Deputy Director of State and Private Forestry at the Southern Region, so we know he will enhance our strong connection with the Southern Region and the customers we serve together. Welcome, Bruce! |
Southern Pines Research
Booker, Fitzgerald L.; Maier, Christopher A. 2001. Atmospheric carbon dioxide, irrigation, and fertilization effects on phenolic and nitrogen concentrations in loblolly pine (Pinus taeda) needles. Tree Physiology. 21: 609-616.
Concentrations of total soluble phenolics, catechin, proanthocyanidins (PA), lignin and nitrogen (N) were measured in loblolly pine (Pinus taeda L.) needles exposed to either ambient CO2 concentration ([CO2]), ambient plus 175 or ambient plus 350 mmol CO2 mol-1 in branch chambers for 2 years. The CO2 treatments were superimposed on a 2 x 2 factorial combination of irrigation and fertilization treatments. In addition, we compared the effects of branch chambers and open-top chambers on needle chemistry. Proanthocyanidin and N concentrations were measured in needles from branch chambers and from trees in open-top chambers exposed concurrently for two years to either ambient [CO2] or ambient plus 200 mmol CO2 mol-1 in combination with a fertilization treatment. In the branch chambers, concentrations of total soluble phenolics in needles generally increased with needle age. Concentrations of total soluble phenolics, catechin, and PA in needle extracts increased about 11 percent in response to the elevated [CO2] treatments. There were no significant treatment effects on foliar lignin concentrations. Nitrogen concentrations were about 10 percent lower in needles from the elevated [CO2] treatments than in needles from the ambient [CO2] treatments. Soluble phenolic and PA concentrations were higher in the control and irrigated soil treatments in about half of the comparisons; otherwise, differences were not statistically significant. Needle N concentrations increased 23 percent in response to fertilization. Treatment effects on PA and N concentrations were similar between branch and open-top chambers, although in this part of the study N concentrations were not significantly affected by the CO2 treatments in either the branch or open-top chambers. We conclude that elevated [CO2] and low N availability affected foliar chemical composition, which could, in turn, affect plant–pathogen interactions, decomposition rates, and mineral nutrient cycling. (1)
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Boyer, William D. 2001. A generational change in site index for naturally established longleaf pine on a south Alabama Coastal Plain site. Southern Journal of Applied Forestry. 25(2): 88-92.
Research on longleaf pine (Pinus palustris Mill.) has been carried out for over 50 yr on a Coastal Plain site in south Alabama. Studies have included the original second-growth stands and also naturally established third-growth stands. Site index data revealed that estimated site index values for third growth generally exceeded those for second growth. Age 50 site index in 16 study compartments with second growth near index age averaged 66 ft. Estimated site index for third-growth stands recorded in 17 different compartments averaged 81 ft. Nine of the 16 compartments with second-growth stands now include third growth about 40 yr in age. This provided an opportunity to make a direct comparison of generational site index differences within the same compartments. Site index for second growth averaged 65 ft (range 61 to 70 ft), while third growth averaged 83 ft (range 77 to 87 ft). Reasons for this large increase in apparent site quality are unknown, but since soils are the same, some climate changes may be suspect. (2)
Glitzenstein, Jeff S.; Streng, Donna R.; Wade, Dale D.; Brubaker, John. 2001. Starting new populations of longleaf pine ground-layer plants in the outer Coastal Plain of South Carolina, USA. Natural Areas Journal. 21: 89-110.
Southeastern United States habitats dominated by longleaf pine (Pinus palustris Miller) and associated plant species have declined dangerously. Conservation of rare and common plants of longleaf pine habitats may be aided by starting new populations in the field. We review methods for initiating plant populations and integrate information from our studies of rare and common longleaf pine ground-layer plants of the outer South Carolina Coastal Plain. In our experience it is possible to start new populations of most longleaf pine ground-layer plants, including rare species, if (1) seeds are collected from frequently burned sites with reasonably large populations of desired species; (2) appropriate media are used for seedling propagation; (3) outplanting of nursery grown seedlings or direct seeding is done during periods of sufficient soil moisture; and (4) introduction sites properly match habitat requirements (inferred from indicator plants) of desired species, and the sites can be managed with frequent prescribed fire. (3)
Johnsen, Kurt H.; Wear, D.; Oren, R.; and others. 2001. Carbon sequestration and southern pine forests. Journal of Forestry. 99(4): 14-21.
In managed forests, the amount of carbon further sequestered will be determined by (1) the increased amount of carbon in standing biomass (resulting from land-use changes and increased productivity); (2) the amount of recalcitrant carbon remaining below ground at the end of rotations; and (3) the amount of carbon sequestered in products created from harvested wood. Because of the region’s high productivity and industrial infrastructure, carbon sequestration via southern pine forests could be increased, and this may benefit the Nation in terms of global policy commitments. (4)
Klepzig, K.D.; Moser, J.C.; Lombardero, F.J.; and others. 2001. Symbiosis and competition: complex interactions among beetles, fungi, and mites. Symbiosis. 30: 83-96.
Symbioses among bark beetles and their fungal and mite associates involve complex, multi-level interactions. Dendroctonus frontalis attacks and kills southern pines, introducing fungi into the tree. Ophiostoma minus may initially aid beetles in killing trees, but later this "bluestain" fungus becomes an antagonist, competing with larvae for host phloem. Two additional fungi, Entomocorticium sp. A and Ceratocystiopsis ranaculosus are carried within a specialized mycangium and inoculated into phloem where they are fed upon by beetle larvae. The beetle also vectors several species of phoretic mites, which transport spores of O. minus, and C. ranaculosus and can complete their life cycle upon these two fungi. A similar interaction occurs between Ips avulsus and its fungal (Entomocorticium spp.) and mite (Elattoma bennetti) symbionts. Larval beetles feed on fungus, as do the mites. Female mites feed on fungus growing within beetle galleries, swelling to many times their normal size. Larval mites develop and mate within the females who burst open, giving birth to reproductively mature females. These relationships may be best understood by considering the manner in which symbioses vary with time and resources, and the degree to which other species may affect interactions among symbionts. (5)
Saenz, Daniel; Conner, Richard N.; Collins, Christopher S.; Rudolph, D. Craig. 2001. Initial and long-term use of inserts by red-cockaded woodpeckers. Wildlife Society Bulletin. 29(1): 165-170.
Artificial cavities have become a standard management technique for red-cockaded woodpeckers (Picoides borealis). Seventy cavity inserts were installed in our study sites on the Angelina National Forest in eastern Texas from 1990 to 1995. Eighty-two percent of the inserts were used for at least one year. It is still too early to make a direct comparison, but it is likely that inserts will remain usable as long as natural cavities do. Inserts installed in 1990 and 1991 were 20.5 cm in height, whereas inserts installed from 1992 to 1995 were 25.5 cm in height. Larger inserts (25.5 cm) appear to remain usable for a longer time than smaller inserts (20.5 cm). Newer unused inserts are more likely to become active for the first time than older unused inserts. Similar to unused inserts, active cavities (naturally excavated and inserts) that have become inactive are less likely to be reactivated the longer they are inactive. Newness and recency of cavity use and red-cockaded woodpecker activity appear to be important factors in the attractiveness of inserts and naturally excavated cavities. (6)
Welch, Nicole Turrill; Waldrop, Thomas A. 2001. Restoring table mountain pine (Pinus pungens Lamb.) communities with prescribed fire: an overview of current research. Castanea. 66(1-2): 42-49.
Table mountain pine (Pinus pungens Lamb.) communities of the Southern Appalachian Mountains have been maintained historically by lightning- and human-caused fires. Characteristic stands have a table mountain pine overstory, a chestnut oak (Quercus prinus L.), scarlet oak (Q. coccinea Muenchh.), and blackgum (Nyssa sylvatica Marshall) understory, and a mountain laurel (Kalmia latifolia L.) shrub layer. Following more than 60 years of fire suppression, most stands have increased densities of oaks and mountain laurel, as well as fire-intolerant species such as red maple (Acer rubrum L.) and white pine (P. strobus L.). Previous research suggests that restoration of these communities can only be accomplished with high intensity fires that open the forest canopy and expose mineral soil. Opportunities to conduct such burns, however, are limited under current prescribed burning guidelines. Two recent studies examined community response to prescribed burning. Fires of low and medium-low intensity gave rise to abundant regeneration, but may not have killed enough of the overstory to prevent shading. High-intensity fires killed almost all overstory trees but may have destroyed some of the seed. Fires of medium-high intensity may have been most successful; they killed overstory trees and allowed abundant regeneration. Large numbers of these seedlings survived the first growing season as their roots penetrated duff to reach mineral soil. Hardwood rootstocks resprouted after all fire intensities and may out-compete pine seedlings for available resources. Fires of lower intensity than previously recommended may best provide conditions for table mountain pine regeneration, but additional research is needed. Prescriptions calling for lower intensity fires may widen the burning window defined by current guidelines. (7)
Wetlands, Bottomland Hardwoods, and Streams Research
Phillips, Jonathan D.; Marion, Daniel A. 2001. Residence times of alluvium in an east Texas stream as indicated by sediment color. Catena. 45: 49-71.
The relationships between sediment production, storage, and transport in fluvial systems are complex and variable. Key issues in addressing these relationships are the residence times of sediment delivered to the channel, and the proportion derived from recent upland erosion as opposed to remobilized alluvium. The systematic changes in iron geochemistry often experienced by sediments deposited in an anaerobic environment, such as a stream channel or waterlogged floodplain, are used here as an indicator of residence time over contemporary time scales. In areas such as east Texas, where upland soils are high in iron oxide content, these changes are reflected in soil color. Alluvium with red, yellow, or brown colors indicating ferric oxidized iron and sufficient organic matter for reduction to occur indicates a short (< 1 year) residence time. Redox features along root channels may indicate the residence time of oxidized material without organic matter. Alluvium with gley colors (Munsell chroma < 3) indicates a longer residence time (> 1 year). Sediments with the longest residence times in alluvial environments (>> 1 year) will not oxidize on exposure to the atmosphere due to the loss of iron, while those with ferrous iron remaining will experience oxidation and color change on exposure. In Loco Bayou, Texas, these indicators of residence time are shown to be generally consistent with other field evidence of erosion and sedimentation. Further, the color indicators correctly indicate the residence time in several cases where the latter is known from field observations. (8)
Stanturf, John A.; Schoenholtz, Stephen H.; Schweitzer, Callie Jo; Shepard, James P. 2001. Achieving restoration success: myths in bottomland hardwood forests. Restoration Ecology. 9(2): 189-200.
Restoration of bottomland hardwood forests is the subject of considerable interest in the Southern United States, but restoration success is elusive. Techniques for establishing bottomland tree species are well developed, yet problems have occurred in operational programs. Current plans for restoration on public and private land suggest that as many as 200,000 ha could be restored in the Lower Mississippi Alluvial Valley alone. The ideal of ecological restoration is to reestablish a completely functioning ecosystem. Although some argue that afforestation is incomplete restoration, it is a necessary and costly first step but not an easy task. The 1992 Wetlands Reserve Program in Mississippi, which failed on 90 percent of the area, illustrates the difficulty of broadly applying our knowledge of afforestation. In our view, the focus for ecological restoration should be to restore functions, rather than specifying some ambiguous natural state based on reference stands or pre-settlement forest conditions. We view restoration as one element in a continuum model of sustainable forest management, allowing us to prescribe restoration goals that incorporate landowner objectives. Enforcing the discipline of explicit objectives, with restoration expectations described in terms of predicted values of functions, causal mechanisms, and temporal response trajectories, will hasten the development of meaningful criteria for restoration success. We present our observations about current efforts to restore bottomland hardwoods as nine myths, or statements of dubious origin, and at best partial truth. (9)
Southern Appalachians Research
Swank, W.T.; Vose, J.M.; Elliott, K.J. 2001. Long-term hydrologic and water quality responses following commercial clearcutting of mixed hardwoods on a Southern Appalachian catchment. Forest Ecology and Management. 143: 163-178.
Long-term changes (~ 20 years) in water yield, the storm hydrograph, stream inorganic chemistry, and sediment yield were analyzed for a 59 ha mixed hardwood covered catchment (Watershed 7) in the Southern Appalachian Mountains (USA) following clearcutting and cable logging. The first year after cutting, streamflow increased 26 cm or 28 percent above the flow expected if the forest had not been cut. In subsequent years, discharge increases declined at a rate of 5–7 cm per year until the fifth year, when changes in flow returned to baseline values. Later in forest succession, between ages 15 and 18 years, both significant increases and decreases in annual water yield were observed; these discharge dynamics are discussed in relation to vegetation regrowth dynamics. Flow responses predicted from an empirical regional scale model were within 17 percent of experimental values during the first 4 years of regrowth. Intra-annual analysis showed that proportionally larger increases (48 percent) in flow occurred in the low flow months of August–October. Storm hydrograph analysis showed that, on an average, initial flow rate and peakflow rates increased 14–15 percent, and stormflow volume increased 10 percent.
Analyses of stream solute concentrations and catchment nutrient fluxes showed small increases in nutrient losses following clearcutting and logging. Responses were largest the third year after treatment, with annual values of 1.3, 2.4, 2.7, 3.2, 1.4, 0.39, and 2.1 kg ha-1 for NO3-N, K, Na, Ca, Mg, S, and Cl, respectively. Explanations for the retention of nutrients and high ecosystem resistance and resilience are discussed in relation to internal biogeochemical cycles based on long-term process level studies on the catchment. A second, sustained pulse of NO3– to the stream (exceeding post-harvest values) observed later in succession is also discussed in the context of ecosystem processes. Large increases in sediment yield were measured immediately after road construction due to two major storm events. Subsequently, during logging, sediment yield from roads was greatly reduced and insignificant when logging activities were completed. In contrast, cumulative increases in sediment yield were observed downstream over the next 15 years, which illustrate the lag between pulsed sediment inputs to a stream and the routing of sediments through a stream system. The relevance of sedimentation to stream sustainability is discussed in the context of long-term responses in the benthic invertebrate community structure and productivity measured on Watershed 7. (10)
Interior Highlands Research
Cain, Michael D.; Shelton, Michael G. 2001. Secondary forest succession following reproduction cutting on the Upper Coastal Plain of southeastern Arkansas, USA. Forest Ecology and Management. 146: 223-238.
To contribute to an understanding of forest management on secondary forest succession, we conducted vegetation surveys in a chronosequence of pine stands ranging in age from 1 to 59 years. Adjacent areas were compared at 1, 7, 12, and 17 years following two reproduction cutting methods (clearcuts or pine seed-tree cuts); a 59-year-old pine stand that was periodically thinned was also included to represent conditions before reproduction cutting. Because average or better natural loblolly and shortleaf pine (Pinus taeda L. and P. echinata Mill.) seed crops coincided with the planned site disturbances, pines dominated the seedling-size classes at 1 and 7 years after reproduction cutting, the sapling-size classes at 7, 12, and 17 years after reproduction cutting, and the small- and large-tree size classes at 12, 17, and 59 years after reproduction cutting. For seedling size classes, three measures of woody plant diversity (Shannon's (H'), Simpson's (D), and evenness (e) indices) tended to increase from 1 to 12 years after reproduction cutting. In the sapling-size classes, H' and D diversity indices were highest at 17 years and lowest at 59 years after reproduction cutting. For small-tree size classes, H', and D were highest at 7 years and lowest at 12 years after reproduction cutting. Across all but the large-tree size classes, woody species richness peaked 7 years after reproduction cutting. Naturally regenerated pines achieved complete crown closure by 17 years after reproduction cutting; consequently, the presence of shade-tolerant woody plants increased in the understory, and shade-intolerant herbaceous plants disappeared from the forest floor. (11)
Large Scale Assessment and Modeling Research
Bragg, Don C. 2001. Potential relative increment (PRI): a new method to empirically derive optimal tree diameter growth. Ecological Modelling. 137: 77-92.
Potential relative increment (PRI) is a new method to derive optimal diameter growth equations using inventory information from a large public database. Optimal growth equations for 24 species were developed using plot and tree records from several states (Michigan, Minnesota, and Wisconsin) of the North Central US. Most species were represented by thousands of individuals measured across an extensive geographic region that presumably covered a large range of possible environmental conditions. Thus, it was assumed that the individuals growing at the highest rate for each diameter class represented a reasonable estimate of size-specific optimal growth. Comparison of PRI equations among several hardwood and conifer species of differing shade tolerance indicated that unique patterns of optimal diameter growth result. The PRI methodology is similar to other optimal growth models in both shape and trends of predicted growth, but is easier to calculate and offers more flexibility than many other designs. (12)
Greenberg, Cathryn H. 2001. Spatio-temporal dynamics of pond use and recruitment in Florida gopher frogs (Rana capito aesopus). Journal of Herpetology. 35(1): 74-85.
This study examines spatio-temporal dynamics of Florida gopher frog (Rana capito aesopus) breeding and juvenile recruitment. Ponds were situated within a hardwood-invaded or a savanna-like longleaf pine-wiregrass upland matrix. Movement (N = 1444) was monitored using intermittent drift fences with pitfall and funnel traps at eight isolated, ephemeral ponds February 1994 to January 1999. Adult pond use was low but relatively constant among years and did not differ between habitat matrices. Juvenile recruitment was significantly higher in the savanna-like upland matrix. The number of adults using ponds was positively correlated with the number of next-year's recruits in only one year. Recruitment rates were relatively low (maximum 175 captured/pond/yr), but juveniles were produced from most ponds in three of five years. Recruitment was negligible in 1994 because of ponds drying and in 1997 for unknown reasons. Juvenile body size differed significantly among years and ponds. Body size was negatively correlated with the number of juveniles exiting ponds in only one year, suggesting that intraspecific competition is only one of many factors affecting juvenile body size. Most emigration by metamorphic juveniles occurred May through August and was unrelated to rainfall. Dates of first emergence and length of emigration periods varied. A high proportion of juveniles with tailbuds and similar tailbud lengths in most months suggest that metamorphosis occurred throughout the emigration period. High variability in juvenile recruitment success and significant differences in body size among years and ponds suggests that each is influenced by factors at both a landscape (e.g., rainfall and pond hydrology) and within-pond scale (e.g., competition and predation). (13)
Kilgo, John C. 2000. Hope is the thing with feathers [book review]. Wilson Bulletin. 112(4): 570-571.
Hope Is the Thing with Feathers, written by Christopher Cokinos, presents accounts of the lives and deaths of six extinct species (or races) of North American birds: Carolina parakeet, ivory-billed woodpecker, heath hen, passenger pigeon, Labrador duck, and the great auk. The message of Cokinos’ book is that we must do more than hope; we must act to prevent the extinction of the species we still have. An important step in this process is remembering the species and learning from the mistakes that led to their extinction. (14)
Ewers, B.E.; Oren, R.; Johnsen, K.H.; Landsberg, J.J. 2001. Estimating maximum mean canopy stomatal conductance for use in models. Canadian Journal of Forest Research. 31: 198-207.
Fertilized (F) and irrigated and fertilized (IF) stands of Pinus taeda L. produced twice the leaf area index of irrigated (I) and control (C) stands. Based on sap flux-scaled mean stomatal conductance (GS), we found that stomatal conductance in F was half that in other treatments. During the growing season, GS was related to vapor pressure deficit (D) and soil moisture. During the cooler season, soil moisture was high and light accompanied D in controlling GS. Under all conditions and treatments, the rate of decrease in GS with D was proportional to GS at low D (= 1 kPa). We evaluated whether GS can be used as an input to growth models and used a simple growth model (3-PG), which also predicts stand transpiration (EC), to compare with direct EC measurements in the four stands. Model predictions of monthly EC based on Penman–Montieth equation parameterized with maximum GS (GSmax) estimated under highest "native" soil moisture (0.07 m3.m3) produced long-term values within 10 percent of measured EC. When the model was parameterized with GSmax estimated under experimentally raised soil moisture, or with porometrically measured conductance, EC values were consistently overpredicted from 12 to 33 percent. Thus, sap-flux scaled mean canopy stomatal conductance obtained under non-limiting light conditions, low D, and highest native soil moisture, is the most appropriate parameter value for certain single-leaf type of models. (15)
Oren, Ram; Ellsworth, David S.; Johnsen, Kurt H.; and others. 2001. Soil fertility limits carbon sequestration by forest ecosystems in a CO2–enriched atmosphere. Nature. 411: 469-472.
Northern mid-latitude forests are a large terrestrial carbon sink. Ignoring nutrient limitations, large increases in carbon sequestration from carbon dioxide (CO2) fertilization are expected in these forests. Yet, forests are usually relegated to sites of moderate to poor fertility, where tree growth is often limited by nutrient supply, in particular nitrogen. Here we present evidence that estimates of increases in carbon sequestration of forests, which is expected to partially compensate for increasing CO2 in the atmosphere are unduly optimistic. In two forest experiments on maturing pines exposed to elevated atmospheric CO2, the CO2-induced biomass carbon increment without added nutrients was undetectable at a nutritionally poor site, and the stimulation at a nutritionally moderate site was transient, stabilizing at a marginal gain after three years. However, a large synergistic gain from higher CO2 and nutrients was detected with nutrients added. This gain was even larger at the poor site (threefold higher than the expected additive effect) than at the moderate site (twofold higher). Thus, fertility can restrain the response of wood carbon sequestration to increased atmospheric CO2 sequestration to increased atmospheric CO2. Assessment of future carbon sequestration should consider the limitations imposed by soil fertility, as well as interactions with nitrogen deposition. (16)
Rauscher, H. Michael; Spearman, John E., Jr.; Fout, C. Preston; and others. 2001. Talking high-tech turkey: USDA uses new software to analyze habitat management scenarios. Tree Farmer. 20(3): 6-9.
Researchers at the USDA Forest Service, Northeastern and Southern Research Stations, with many collaborators, have been developing a computer software product called the NED Decision Support System. This program is designed to help forestry consultants and their private landowner clients develop goals, assess current and potential conditions, provide ways to study and select from different scenarios, and produce management plans for their forest properties. This NED process has recently been applied to Deer Hill Tree Farm in Gourdin, SC. The authors discuss the results of field testing NED at a 1000 acre family-operated farm. (17)
Wilson, A. Dan. 2001. Oak wilt: a potential threat to southern and western oak forests. Journal of Forestry. 99(5): 4-11.
Oak wilt is recognized as one of the most destructive diseases to afflict oak species in the United States. The distribution and development of oak wilt in our eastern and midwestern oak forests has been closely linked to changes in forest stand composition, forest management practices, and pathogen dissemination facilitated by human and vector activity. The potential for oak wilt to spread into southern and western States and its possible impacts are discussed. The Texas experience with an oak wilt epidemic provides useful perspectives and suppression alternatives for other States not yet touched by this malady. (18)
Inventory and Monitoring Research
Dean, Thomas J.; Baldwin, V. Clark, Jr. 1996. Crown management and stand density. In: Carter, Mason C., ed. Growing trees in a greener world: industrial forestry in the 21st century; 35th LSU forestry symposium; 1996 January 10-11; Baton Rouge, LA. Baton Rouge, LA: Louisiana State University Agricultural Center: 148-159a-e [159ii revised].
Stand density management allows a forester to utilize mortality and promote individual tree vigor. However, even after four decades of spacing studies, planning for stand-density management remains a difficult problem. Forest management approaches the problem with sophisticated analysis, but the heart of the analysis depends on statistical growth models fit to data from empirical field trials. Statistical growth-and-yield simulators interface poorly at times with modern forest management analyses. Even though no better predictor of the next rotation exists than the performance of the previous rotation, history data does not exist for every stand, and the combinations of species, density management, soils, and topography create a matrix too large to test with spacing studies. Furthermore, changes in cultural treatments, product specifications, and the physical environment diminish the predictive value of field trials. Theories are emerging from recent work to support density-management planning. These theories focus on the dynamics of crown dimensions in relationship to stand development and average tree spacing and may aid in developing sound density-management decisions and managing for desired stand qualities. In addition, they may aid in overcoming some of the deleterious effects of climate change, air quality, and site degradation. Mechanistic linkages between the crown and the stem suggest new uses for traditional treatments that may stimulate productivity and improve value. (19)
Vissage, John S. 2000. Forest statistics for Southwest-North Alabama, 1999. Resour. Bull. SRS-56. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 50 p.
This report summarizes a 1999 inventory of the forest resources of a seven-county area of Alabama. Major findings are highlighted in text and graphs; detailed data are presented in 49 tables. (20)
Vissage, John S. 2000. Forest statistics for Southwest-South Alabama, 1999. Resour. Bull. SRS-55. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 50 p.
This report summarizes a 1999 inventory of the forest resources of a five-county area of Alabama. Major findings are highlighted in text and graphs; detailed data are presented in 49 tables. (21)
Foundation Programs Research
Connor, Kristina F.; Bonner, Franklin T. 2001. The effects of desiccation on seeds of Acer saccharinum and Aesculus pavia: recalcitrance in temperate tree seeds. Trees. 15: 131-136.
This study was undertaken to determine how the results from lipid, moisture, and differential scanning calorimetry analyses conducted on silver maple (Aceraceae: Acer saccharinum L.) and red buckeye (Hippocastanaceae: Aesculus pavia L.) compared with those obtained from previous studies on white and water oaks (Fagaceae: Quercus alba and Q. nigra), and the tropical zone species American muskwood (Meliaceae: Guarea guidonia) and carapa (Meliaceae: Carapa guianensis). Seeds were air-dried at room temperature for 9–11 days. At intervals, germination was tested, moisture determined, and lipids extracted. It was found that, like the other recalcitrant seeds, (1) viability was greatly reduced or lost after 11 days of drying, (2) percentage changes in individual fatty acids were not related to seed viability, and (3) results from the differential scanning calorimetry studies revealed a strong relationship between enthalpy/onset data from the embryo and cotyledon tissues and loss of viability. Also, silver maple seeds experienced a 50 percent reduction in viability by day 5 of drying and retained an axis moisture content over 25 percent throughout the experiment. However, unlike the other recalcitrant seeds surveyed, both silver maple and red buckeye had a significant reduction in the total amount (mg/g) of cotyledon lipids as the experiment progressed. However, no decrease in the unsaturated/saturated fatty acid ratio was found, so we conclude that in these species, lipid peroxidation is not a marker of declining seed viability. Also, red buckeye seeds did not lose 50 percent viability until after day 8 of the experiment, and axis moisture content fell well below 20 percent as the seeds dried. (22)
Deller, Steven C.; Tsai, Tsung-Hsiu (Sue); Marcouiller, David W.; English, Donald B.K. 2001. The role of amenities and quality of life in rural economic growth. American Journal of Agricultural Economics. 83(2): 352-365.
A structural model of regional economic growth is estimated using data for 2243 rural US. counties. Five indices designed to capture specific amenity and quality of life characteristics are constructed using 54 separate indicators. Results suggest that amenity characteristics can be organized into consistent and meaningful empirical measures that move beyond ad hoc descriptions of amenities. In addition to insights into the influence of local characteristics ranging from tax burdens to income distribution on regional economic growth, results suggest that predictable relationships between amenities, quality of life, and local economic performance exist. (23)
Hawkins, Leigh K.; Dane, Fenny; Kubisiak, Thomas L.; and others. 2001. Linking mapping in a watermelon population segregating for fusarium wilt resistance. Journal of American Society for Horticultural Science. 126(3): 344-350.
Isozyme, randomly amplified polymorphic DNA (RAPD), and simple sequence repeats (SSR) markers were used to generate a linkage map in an F2 and F3 watermelon (Citrullus lanatus (Thumb.) Matsum. & Nakai) population derived from a cross between the fusarium wilt (Fusarium oxysporum f. sp. niveum) susceptible "New Hampshire Midget" and resistant PI 296341-FR. A 112.9 cM RAPD-based map consisting of 26 markers spanning two linkage groups was generated with F2 data. With F3 data, a 139 cM RAPD-based map consisting of 13 markers covering five linkage groups was constructed. Isozyme and SSR markers were unlinked. About 40 percent to 48 percent of the RAPD markers were significantly skewed from expected Mendelian segregation ratios in both generations. Bulked segregant analysis and single-factor analysis of variance were employed to identify RAPD markers linked to fusarium wilt caused by races 1 and 2 of F. oxysporum f. sp. niveum. Current linkage estimates between the resistance trait and the marker loci were too large for effective use in a marker-assisted selection program. (24)
Kabir, Mohammed Firoz; Daud, Wan M.; Khalid, Kaida B.; Sidek, Haji A.A. 2001. Temperature dependence of the dielectric properties of rubber wood. Wood and Fiber Science. 33(2): 233-238.
The effect of temperature on the dielectric properties of rubber wood was investigated in three anisotropic directions—longitudinal, radial, and tangential, and at different measurement frequencies. Low frequency measurements were conducted with a dielectric spectrometer, and high frequencies used microwave applied with open-ended coaxial probe sensors. Dielectric constants and dielectric loss factors were measured at temperatures from 25 to 100°C. A large dielectric dispersion occurred at frequencies less than 10 Hz and at temperatures more than 60°C. The minimum peak value of the dielectric loss factors shifted towards higher frequencies at higher temperatures in all three grain directions. The tangential direction showed the highest activation energy. The dielectric constant decreased as frequency increased from 1 to 10 GHz, and thereafter remained unchanged with additional frequency increases. The dielectric constant exhibited higher values at higher temperatures. The dielectric loss factor showed a peak value at around 10 GHz at 25°C. (25)
Kabir, M.F.; Schmoldt, D.L.; Schafer, M.E. 2001. Roller-transducer scanning of wooden pallet parts for defect detection. In: Thompson, D.O.; Chimenti, D.E. Review of progress in quantitative nondestructive evaluation. 20: 1218-1225.
Ultrasonic scanning experiments were conducted on two species of pallet deckboards using rolling transducers in a pitch-catch arrangement. Sound and unsound knots, cross grain, bark pockets, holes, splits, decay, and wane were characterized using several ultrasound parameters. Almost all parameters displayed sensitivity to defects distinctly from clear wood regions—being greatest for unsound knots, bark pockets, decay, holes, splits, and less for sound knots and cross grain. This study supports our conjecture that on-line inspection of wooden pallet parts is possible using rolling-transducer ultrasonic inspection. (26)
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