Mary A. Topa, PhD
Phone: |
440.602.3838 |
 |
E-mail: |
||
Title: |
Director of Science and Research |
|
Education: |
Ph.D., Duke University |
|
Adjunct Professorships: |
Adjunct Professor, Department of Biology, Case Western Reserve University
|
Curriculum Vitae
Research Interests
As a plant physiological ecologist, my research has focused on how trees respond to environmental stress. Of particular interest to me is how root system – roots plus rhizosphere biota – function changes in response to natural and anthropogenic stresses. However, there is an interdependence between the root function of supplying nutrients and water, and the shoot function of supplying trees with carbon via photosynthesis. Consequently, any environmental stress that impacts nutrient or water uptake by roots will alter shoot activities; conversely, any environmental stress that impacts carbon fixation by leaves will alter root activities. Because of their long-lived perennial nature, most trees are buffered against short-term stresses. However, adaptation to longer-term stresses, such as flooding or nutrient-poor conditions, is usually found in specific populations with a genetic predisposition to withstand those stresses. To better understand the mechanism of tolerance to environmental stress, I work with populations that exhibit tolerance to a specific stress, and compare them with populations that are more susceptible to this stress.
My current and long-range research interests focus on how 1) Root systems of long-lived perennials respond to natural edaphic stresses and resource heterogeneity, and anthropogenic stresses, 2) Root system responses may account for the wide variation in above-ground growth that is generally observed in tree populations, and 3) Environmental stress alters whole-plant carbon and nutrient source/sink relationships; and 4) Rhizophere biota alter root system and belowground ecosystem function.
Recent Publications
Burke DJ, Martin KJ, Rygiewicz PT & Topa MA (2006) Relative abundance of ectomycorrhizas in a managed loblolly pine (Pinus taeda L.) genetics plantation as determined through terminal restriction fragment length polymorphism (TRFLP) profiles. Canadian Journal of Botany, 84: 924-932.
Burke DJ, Kretzer AM, Rygiewicz PT & Topa MA (2006) Soil bacterial diversity in a loblolly pine plantation: Influence of ectomycorrhizas and fertilization. FEMS Microbiology Ecology, 57: 409-419.
Martin TA, Dougherty PM, Topa MA & McKeand SE (2005) Strategies and case studies for incorporating ecophysiology into southern pine tree improvement programs. Southern Journal of Applied Forestry, 29(2): 70-80.
Burke DJ, Martin KJ, Rygiewicz PT & Topa MA (2005) Ectomycorrhizal fungi identification in single and pooled root samples: terminal restriction fragment length polymorphism (TRFLP) and morphotyping compared. Soil Biology and Biochemistry, 37: 1683-1694.
Topa MA, McDermitt DJ, Yun S-C & King PS (2004) Do elevated ozone and variable light alter carbon transport to roots in sugar maple? New Phytologist, 162: 173-186.
Topa MA (2004) Tree Physiology: Root System Physiology. In: The Encyclopedia of Forest Sciences, (J. Burley, J. Evans and J. Youngquist, eds.). Elsevier Science Ltd., London, UK. pp. 1606-1616.
Yang WQ, Murthy R, King PS & Topa MA (2002) Diurnal changes in gas exchange and carbon partitioning in needles of fast- and slow-growing families of loblolly pine (Pinus taeda). Tree Physiology, 22: 489-498.
Retzlaff WA, Blaisdell GK & Topa MA (2001a) Seasonal changes in water source of four families of loblolly pine (Pinus taeda L.). Trees Structure and Function, 15: 154-162.
Retzlaff WA, Handest JA, O’Malley DM, McKeand SE & Topa MA (2001b) Whole-tree biomass and carbon allocation of juvenile trees of loblolly pine (Pinus taeda L.): influence of genetics and fertilization. Canadian Journal of Forest Science, 31: 960-970.
Topa MA, Vanderklein DW & Corbin AT (2001) Effects of elevated ozone and low light on diurnal and seasonal carbon gain in sugar maple (Acer saccharum Marsh.). Plant Cell and Environment, 24: 663-677.
Botton B, Chalot M, Dizengremel P, LeTacon F, Rygiewicz P & Topa M (eds.) (2001) Dynamics of Physiological Processes in Woody Roots. Tree Physiology, 21: 71-200, Heron Publishing, Victoria Canada.
