Photo of Shi-Jean Susana Sung

Shi-Jean Susana Sung

Research Plant Physiologist
2500 Shreveport Highway
 Pineville, LA 71360
Phone: 318-473-7233
susana.sung@usda.gov

Current Research

The primary thrust of current research is in the areas of longleaf pine seedling production, field establishment, and field performance with emphasis on root system architecture, sapling physical stability (e.g., wind firmness), stem sinuosity, and physiologcial and growth response to prescribed burns. The long-term effects of container types and sizes on longelaf pine are being evaluated. Different strategies including nursery fertilization rate and site preparation methods are being explored to enhance the acceleration of stem growth to reduce resisdence time of the grass stage. Effects of sivilcultural management practices are studied on longleaf pine, slash pine and Ponderosa pine stands.

Research Interests

  • Physiology of forest species including longleaf pine, Ponderosa pine, oaks, and American chestnut.
  • Seedling and tree root system architecture.
  • Tree responses to climate changes such as drought, flood, and heat and infestation of insects and diseases.

Past Research

  • Physiology, biochemistry, morphology, and silviculture of loblolly pine, sweetgum, northern red oak, white oak, souther red oak, and cherrybark oak.
  • Nursery protocols and artificial regeneration strategies for loblolly pine and several oak species.
  • The seasonal dynamics of carbon sink and source relationship in loblolly pine, oaks, sweetgum, and longleaf pine.
  • The adaptive and maintenance intermediately sugar metabolic pathways in agriculture and horticulture crops and forest trees.
  • Phosphorus fertilization and mycorrhizal colonization in pines and sweetgum.
  • Herbicides and weed biology.

Why This Research is Important

With increasing interests from the public and private sectors of forest professionals and land owners to restore, improve, and maintain longleaf pine ecosystems in its natural range across southern U.S, many aspects of longelaf biology and physiology are either unknown or mis-leading. For example, a longleaf pine seedling can emerge from the grass stage (> 12 cm in height) within 1 to 4 years after planting. Seedlings tend to stay in the grass stage longer if they are shaded by competing vegetation. Restoration has to come from the artificial regeneration if there is no longleaf on site or the natural regeneration is not feasible. Although more than 85% of longleaf pine planted is from the container stock, there remain many issues with container-grown stock. Sapling windfirmness, or lack of it, is one. Bareroot seedlings have a narrow window of planting (< 7 days from lifting) and survive poorly in drought. But they possess a root system similar to that of the naturally regenerated seedlings and are more wind firm compared to the container stock.

Education

Ph.D. in Agronomy and Soils, 1982
Auburn University
M.S. in Plant Physiology and Weed Science, 1977
Virginia Polytechnic Institute and State University
B.S. in Botany, 1975
National Chung-Hsing University, Taichung, Taiwan

Featured Publications and Products

Publications

Research Highlights


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R&D Affiliations
Research Topics
External Resources
  • The sites listed below are third-party sites which the Forest Service has provided for reference only.
  • ResearchGate Profile logo ResearchGate Profile