Howard S. Neufeld
Ph.D., University of Georgia, 1984

Telephone: 828-262-2683
FAX: 828-262-2127

Mailing Address:     Dr. Howard S. Neufeld
                                Department of Biology
                                572 Rivers Street
                                Appalachian State University
                                Boone, NC 28608

Research Interests
Masters Theses Directed
Classes Taught

Research Interests My research for many years has focused on the impacts of tropospheric ozone on plants native to Great Smoky Mountains National Park. From 1988-1992 I was the principal investigator on the ozone exposure program funded by both the National Park Service and the U.S. EPA. We found a variety of species sensitive to elevated ozone, particularly early successional species, both herbaceous and woody. In the field, nearly 100 species showed foliar symptoms consistent with ozone exposure, which is around 6% of the flora of the Park. However, the vast majority of the plants in the exposure chambers showed no adverse growth effects except at ozone exposures above ambient, indicating that such effects in the field may be nonexistent or hard to detect.  However, there are several species that do show exceptional amounts of foliar injury in the field, such as the perennial herbs tall milkweed (Asclepias exaltata), crownbeard (Verbesina occidentalis), cutleaf coneflower (Rudbeckia laciniata), and woody plants such as yellow poplar (Liriodendron tulipifera) and black cherry (Prunus serotina). Tall milkweed, for example, often loses all of its leaves by the end of August even at ambient levels of ozone.

    Since 1999 I have worked with researchers from Auburn University (Drs. Art Chappelka and Russ Muntifering), the University of Newcastle-Upon-Tyne in England (Dr. Alan Davison - now retired), the Air Pollution Lab of the USDA in Raleigh, NC (Dr. Kent Burkey), the U.S. EPA (Dr. Pete Finkelstein), and Dr. Sandy McLaughlin from Oak Ridge, TN (now retired) on the impacts of ozone on native wildflowers in the Park.  We have received funding from the National Geographic Society, Friends of the Smokies, the National Park Service, the U.S. EPA, and Appalachian State University to work on ozone responses in these plants in the Smokies and have spent many a summer studying these plants.  We now have several publications out which you can download if you'd like (see Representative Publications for pdfs of these papers). Other papers are in various stages of preparation. 

       I currently have seven graduate students in various stages of completion of their theses. Brad Miller is a Ph.D. student in the Forestry School at Virginia Tech, working on forest soils and mycorrhizae, but did his Masters thesis work here on nutrient loading of red spruce seedlings. He should defend his thesis this fall. Scott Taylor is finishing up his work on the endangered wetland shrub, Pondberry (Lindera mellissifolia). Scott looked at the reproductive biology and seed germination strategies of this shrub, and now works as a wetlands consultant for a firm in Hendersonville, NC. Melinda Roberts is nearly finished writing up her thesis on the water relations of coneflowers and how this affects their response to ozone. Melinda's work has resulted in her winning three outstanding poster awards, and we hope to publish her results soon. Chrisha Dolan did her research on the leaf anatomy of coneflowers and its relation to ozone sensitivity in this species. She currently works as a plant ecologist for the U.S. Marines at Fort Bragg, NC. Ann Huyler is nearing completion of her research into the effects of short-term chronic and acute ozone exposures on the foliar and biochemical responses of tulip poplar seedlings. She is currently working with Dr. Kent Burkey to analyze her leaf samples for anti-oxidants, and should complete her thesis by next May. Cori-Alice Holladay is studying the impacts of heavy metal pollution (in particular, Ni) on the ecophysiology of loblolly pines (Pinus taeda). This is both a lab and field project, with the field work taking place on the Savannah River Project near Aiken, SC. She should, like Ann, be done by next May. My seventh student, Fern Perkins, is working on the impacts of nitrogen deposition on the ecophysiology of foliose lichens. She is studying in situ impacts on the lichen Umbilicaria mammulata from samples she and I collected across the N deposition gradient in the eastern United States from Maine to West Virginia, and she will also fertilize her lichens with extra N both in the field and in the Phytotron at NC State University. She should complete her thesis in about a year.

    My former students have worked on a variety of subjects: Songqiao Huang, my first student to finish her Masters thesis (1992), researched the effects of controlled ozone exposures on tulip poplar seedlings and is now a professor at Los Angeles Valley Community College in California. James Hutcherson worked on the effects of excluding air pollutants on the ecophysiology of mature red spruce and is currently a professor at Blue Ridge Community College in Hendersonville, NC.  His work was published in the Journal of Environmental Quality (sorry, no pdf available). Stacey Fredenberg studied the cadmium tolerance of baldcypress trees under flooded and non-flooded conditions. After obtaining another Masters in Civil Engineering (yeh, wow!) she now works for Parsons Consulting in Atlanta, GA. Ken McCarron studied the ecophysiology and phenology of Galax aphylla (now G. urceolata) and then went to work at the Savannah River Plant as a plant ecophysiology technician. After several years there, he went to work with Dr. Alan Knapp at Kansas State University, where he obtained his Ph.D. He recently began working as a research plant ecologist for the National Park Service Inventory & Monitoring program, based out of Fort Sumter National Monument in SC. Denise Williams studied the reproductive and population ecology of Microstegium vimineum, a noxious, invasive grass. She found that it could have over 50,000 seeds per m2 in the Smokies. She spent several years in the Peace Corps in El Salvador and is now teaching biology at Caldwell Community College in Boone, NC. Karen Geissenger (now Karen Colson) investigated the effects of grazing on a wetland adjacent to the Blue Ridge Parkway near Blowing Rock, NC.  Upon completion of her degree, Karen worked as a wetland consultant in Florida for over a year. After her marriage she and her husband moved to Boise, Idaho, where she is working as a vegetation consultant for the USGS. Jonathan Horton studied sunfleck responses in the grass Microstegium vimineum, a shade-tolerant, C4 species and obtained his Ph.D. from Northern Arizona University. He is now a faculty member in the Department of Biology at UNC-Asheville. Jonathan's work on sunflecks appeared in Oecologia in 1998 (Horton and Neufeld 1998-pdf). Jim Sobieraj worked on the hydraulic conductivity of the understory evergreen herb, Galax urceolata. He found that this species could be as drought tolerant as some desert plants! Lara Souza finished her thesis on the responses of tall milkweed (Asclepias exaltata) to ozone in the Smokies in 2003, and is currently a Ph.D. student with Dr. Nathan Sanders at the University of Tennessee in Knoxville. Here thesis work appeared in the journal Environmental Pollution in 2006 (Souza et al. 2006-pdf). Seth Peoples studied how cutleaf coneflower (Rudbeckia laciniata) responds to ozone also, finished his thesis in 2005, and is now a middle school biology teacher in Greensboro, NC. His work involved measuring foliar injury, photosynthetic decline, and impacts on total non-structural carbohydrate status in these plants. Niky Hughes also finished her thesis in 2005, and investigated the adaptation of Galax to winter conditions in the southern Appalachians.  She was particularly interested in why Galax leaves turn red when exposed to high light in the winter, and looked at effects of anthocyanins on leaf metabolism, including potential anti-oxidant properties, ability to protect the plant against photo-inhibition, and other aspects of the ecophysiology of this very interesting plant.  Her work was published in New Phytologist in 2005 (Hughes et al. 2005-pdf). Corrie Williams worked on the dispersal of juvenile saw-whet owls (I know, this is a little afar from the usual plant based theses, but hey, I'm versatile!), and is now a biology teacher at Watauga High School in Boone, NC. 

Students in my lab develop skills in gas exchange techniques and plant water relations, as well as expertise in basic aspects of plant ecology and plant ecophysiology research. Those working on air pollution related projects become knowledgeable in this field as well.  Most of the Masters theses out of my lab involve a combination of laboratory and field work, including observational and experimental methods. It normally takes my students two summers and three academic years to graduate, but recently, we have been getting some students out in just two years!  All of my former students are now working in their field of choice. 


(* student co-authors)

Neufeld, Howard S. 1983. Effects of light on growth, morphology, and photosynthesis in Baldcypress (Taxodium distichum (L.) Rich.) and Pondcypress (T. ascendens Brongn.) seedlings. Bull. Torr. Bot. Club 110:43-54. Click here for pdf.

Montagnini, Florencia, Howard S. Neufeld and Christopher Uhl. 1984. Heavy metal concentrations in some non-vascular plants in an Amazonian rainforest. Water, Air, and Soil Pollution 21:317-321. Click here for pdf of abstract.

Neufeld, Howard S., Judith A. Jernstedt and Bruce L. Haines. 1985. Direct foliar effects of simulated acid rain. I. Damage,
        growth, and gas exchange. New Phytologist 99:389-405. Click here for pdf.

Haines, Bruce L., Judith A. Jernstedt and Howard S. Neufeld. 1985. Direct foliar effects of simulated acid rain. II. Leaf
        surface characteristics. New Phytologist 99:407-416. Click here for pdf.

Neufeld, Howard S. 1986. Ecophysiological implications of tree architecture for two cypress taxa, Taxodium distichum (L.) Rich. and T. ascendens Brongn. Bull. Torr. Bot. Club 113:118- 124. Click here for pdf.

Neufeld, Howard S. and Robert O. Teskey. 1986. Variation in the amount of foliage on woody shoots and its effects on water relations parameters derived from pressure-volume curves. Can. J. For. Res. 16:239-243. No pdf available.

Neufeld, Howard S., Frederick C. Meinzer, Charles S. Wisdom, M. Rasoul Sharifi, Philip W. Rundel, Mollie S. Neufeld,
        Yoram Goldring and Gary L. Cunningham. 1988. Canopy architecture of Larrea tridentata (DC.) Cov., a desert shrub: Foliage orientation and direct beam radiation interception. Oecologia 77:54-60. No pdf available.

Neufeld, Howard S., Daniel M. Durall, Paul M. Rich and David T. Tingey. 1989. A rootbox for quantitative observations on intact entire root systems. Plant and Soil 117:295-298. Click here for pdf.

Meinzer, Frederick C., Guillermo Goldstein, Howard S. Neufeld, David A. Grantz, and Gayle M. Crisosto. 1992. Hydraulic architecture of sugarcane in relation to patterns of water use during plant development. Plant, Cell & Environment 15:471-477. Click here for pdf.

Neufeld, Howard S., David A. Grantz, Frederick C. Meinzer, Guillermo Goldstein, Gayle M. Crisosto, and Carlos Crisosto. 1992. Genotypic variability of leaf xylem to cavitation in water-stressed and well-irrigated sugarcane. Plant Physiology 100:1020-1028. Click here for pdf.

Hacker, W. David, and Howard S. Neufeld. 1993. The false positive in bioindicators of air pollution. J. of Arboriculture 18:249-250. No pdf available.

Neufeld, Howard S., James R. Renfro, W. David Hacker and David Silsbee. 1992. Ozone in Great Smoky Mountains
        National Park: Dynamics and effects on plants. In "Tropospheric Ozone and the Environment II", Ronald L. Berglund.
        Air & Waste Management Association, Pittsburgh, PA. pgs. 594-617. No pdf available.

Thornton, Frank C., J. Dev Joslin, Paul A. Pier, Howard S. Neufeld, John R. Seiler, James D. Hutcherson*. 1994.
        Cloudwater and ozone effects upon high elevation red spruce: A summary of study results from Whitetop Mountain,
        Virginia. Journal of Environmental Quality 23:1158-1167. No pdf available.

Neufeld, Howard S., E. Henry Lee, James R. Renfro, W. David Hacker, Ben-Hui Yu. 1995. Sensitivity of seedlings of black cherry (Prunus serotina Ehrh.) to ozone in Great Smoky Mountains National Park. 1. Exposure-response curves for
        biomass. New Phytologist 130:447-459. Click here for pdf.

Neufeld, Howard S., James R. Renfro, Songqiao Huang*, W. David Hacker, Deborah Mangis, Arthur H. Chappelka, William E. Hogsett, Andrew A. Herstrom, John A. Laurence, E. Henry Lee, James E. Weber, and David T. Tingey. 1995.
        Assessment of ozone effects on plants native to the southeastern United States. Proceedings of the XI International
        Association of Botanical Gardens, Wuxi, China, Sept. 6-12, 1993. No pdf available.

Neufeld, Howard S., C. Scott Clark, and James A. Weber. 1996. An automated 25 cuvette gas exchange system for the study of plant responses to ozone. In "Air Pollution and Multiple Stresses", Proceedings of the 16th International Meeting for Specialists in Air Pollution Effects on Forest Ecosystems, IUFRO, R. Cox, K. Percy, K. Jensen, and C. Simpson, eds. Sept. 7-9, 1994, Fredericton, NB, Canada. No pdf available.

Horton, Jonathan L.* and Howard S. Neufeld. 1998. Photosynthetic responses of Microstegium vimineum (Trin.) A.
        Camus, a shade-tolerant, C4 grass, to variable light environments. Oecologia 114:11-19. Click here for pdf.

Neufeld, Howard S., E. Henry Lee, James R. Renfro and W. David Hacker. 2000.  Seedling insensitivity to ozone for three
        conifer species native to Great Smoky Mountains National Park. Environmental Pollution 108:141-151. Click here for pdf.

Neufeld, Howard S. and Donald R. Young. 2003. Ecophysiology of the herbaceous layer in temperate deciduous forests.
        In: Gilliam, F. and M. Roberts, eds. The Herbaceous Layer in Forests of Eastern North America. Oxford University Press, pp. 38-90. No pdf available.

Chappelka, A.H., H.S. Neufeld, A.W. Davison, G.L. Somers and J.R. Renfro. 2003. Ozone injury on cutleaf coneflower (Rudbeckia laciniata) andcrown-beard (Verbesina occidentalis) in Great Smoky Mountains National Park. Environmental Pollution 125:53-59. Click here for pdf.

Davison, A.W., H.S. Neufeld, A.H. Chappelka, K. Wolff and P.L. Finkelstein. 2003. Interpreting spatial variation in ozone symptoms shown by cutleaf coneflower, Rudbeckia laciniata L. Environmental Pollution 125:61-70. Click here for pdf.

Finkelstein, Peter L., Alan W. Davison, Howard S. Neufeld, Tilden P. Meyers and Arthur H. Chappelka. 2004. Sub-canopy deposition of ozone in a stand of cutleaf coneflower. Environmental Pollution 131:295-303. Click here for pdf.

Hughes, Nicole M.*, Howard S. Neufeld and Kent O. Burkey. 2005. Functional role of anthocyanins in high light, winter leaves of the evergreen herb Galax urceolata. New Phytologist 168:575-587. Click here for pdf.

Neufeld, Howard S., Arthur.H. Chappelka, Greg L. Somers, Kent O. Burkey, Alan W. Davison and Peter L. Finkelstein. 2006. Visible foliar injury caused by ozone alters the relationship between SPAD meter readings and chlorophyll concentrations in cutleaf coneflower. Photosynthesis Research 87:281-286. Click here for pdf.

Souza, Lara*, Howard S. Neufeld, Arthur H. Chappelka, Kent O. Burkey and Alan W. Davison. 2006. Seasonal development of ozone-induced foliar injury on tall milkweed (Asclepias exaltata) in Great Smoky Mountains National Park. Environmental Pollution 141:175-183. Click here for pdf.

Burkey, Kent O., Howard S. Neufeld, Lara Souza*, Arthur H. Chappelka and Alan W. Davison. 2006. Seasonal profiles of leaf ascorbic acid metabolism in ozone-sensitive wildflowers. Environmental Pollution 143:427-434. Click here for pdf.

Grulke, Nancy E., Howard S. Neufeld, A.W. Davison, M. Roberts* and A.H. Chappelka. 2006. Stomatal behavior of O3-symptomatic and O3-asymptomatic cutleaf coneflowers (Rudbeckia laciniata var. digitata) in Great Smoky Mountains National Park. New Phytologist (available online - pdf).

Dumas, Shay*, Howard S. Neufeld and Melany C. Fisk. Importance of the shrub layer to short-term responses to fire in the Linville Gorge Wilderness Area, North Carolina. Castanea (accepted).

Eullis, Amy*, Melany C. Fisk and Howard S. Neufeld. Growth of Houstonia montana, a rare southern Appalachian endemic plant, in contrasting habitat types. Bulletin of the Torrey Botanical Society (accepted).


Masters Theses Directed

 Huang, Songqiao. 1992. Response of growth and gas exchange of tulip poplar (Liriodendron tulipifera L.) seedlings to
        ozone exposure. 117 pgs.

 Hutcherson, James D. 1993. Effects of ambient pollutants on the physiology and morphology of mature red spruce.
        137 pgs.

 McCarron, James K. 1995. Ecophysiology of Galax aphylla, a clonal, understory evergreen herb in the southern
        Appalachians. 73 pgs. Thesis won 3rd Prize in Cratis D. Williams Thesis Competition.

 Horton, Jonathan L. 1996. Effects of lightflecks on the gas exchange responses of Microstegium vimineum, a shade
        tolerant C4 grass. 65 pgs.

Williams, L. Denise. 1998. Factors affecting growth and reproduction in the invasive grass, Microstegium vimineum.
        59 pgs.

Fredenberg, Stacey. 2000. Effects of soil type and flooding on the response of bald cypress (Taxodium distichum var.
        distichum (L.) Rich.) seedlings to cadmium.

Geissinger, Karen E. 2000. Community changes in a Southern Appalachian wetland after the elimination of grazing. Masters Thesis, ASU. 78 pgs.

Sobieraj, James R., III. 2002. Hydraulic conductivity in petioles and rhizomes of Galax urceolata, an evergreen, understory herb of the Southern Appalachians. Masters Thesis, ASU. 43 pgs.

Souza, Lara. 2003. Seasonal development of ozone-induced foliar injury on tall milkweed (Asclepias exaltata) in Great Smoky Mountains National Park. Masters Thesis, ASU. 75 pgs.

Williams, Amanda Corine. 2003. A natural history of the northern saw-whet owl’s (Aegolius aradicus) breeding biology and juvenile dispersal in the southern Appalachian mountains. Masters Thesis, ASU. 82 pgs.

Hughes, Nicole M. 2004. Functional role of anthocyanins in high light winter leaves of the evergreen herb, Galax urceolata. Masters Thesis, ASU. 48 pp.

Dumas, Sara Jean. 2004. Community and ecosystem responses following fire in the Linville Gorge Wilderness Area. Masters Thesis, ASU. 42 pp.

Peoples, Seth J. 2005. Physiological effects of ozone air pollution on Rudbeckia laciniata in Great Smoky Mountains National Park. Masters Thesis, ASU. 47 pp.

Miller, Bradley W. 2006. Exponential fertilization effects on nursery raised red spruce seedling growth, ectomycorrhizal colonization, and nutrient uptake in forest soil amended potting mixtures.. Masters Thesis, ASU. (in prep.).

Roberts, Melinda. 2006. Interactions between water relations and ozone responses in cutleaf coneflower (Rudbeckia laciniata) in Great Smoky Mountains National Park. Masters Thesis, ASU. (in prep.).

Taylor, O. Scott. 2006. Conservation and reproductive biology of the Federally endangered shrub Lindera mellissifolia in coastal North Carolina. Masters Thesis, ASU. (in prep.).

Dolan, Chrisha. 2007. The role of leaf anatomy in determining the sensitivity of cutleaf coneflower to ozone. Masters Thesis, ASU. (in prep.).

Huyler, Ann. 2007. Effects of short-term chronic and acute ozone exposures on the physiological and biochemical responses of tulip poplar (Liriodendron tulipifera L.) seedlings. Masters Thesis, ASU.

Holladay, Cori-Alice. 2007. The impacts of flooding on the uptake of and ecophysiological responses to the heavy metal nickel in loblolly pine (Pinus taeda L.) seedlings. Masters Thesis, ASU.

Perkins, Fern. 2007. The ecophysiological responses of the foliose lichen Umbilicaria mammulata to enhanced nitrogen deposition. Masters Thesis, ASU.


Classes Taught

 Spring Courses                                                          Fall Courses

Air Pollution 3320                                 Plant Physiology 4555
Introductory Biology 1102                    Biometrics 5777

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