Natural Resource Ecology and Management - Faculty

Stephen W. Hallgren
Associate Professor

Office:	022 Ag Hall
Address:	008CAg Hall Stillwater, OK 74077
Phone:	(405) 744-6805
Fax:	(405) 744-3530
Email:	steve.hallgren@okstate.edu

Education
BS:	Forest Science, 1972, University of Minnesota, St. Paul
MS:	Oregon State University; 1978; Forest Ecology
PhD:	University of California, Berkeley; 1984; Forest Biology

Links
Curriculum Vitae

Teaching

FOR 3213	Forest Ecology
FOR 4500	Forest Problems
FOR 5000	Research and Thesis
FOR 5010	Graduate Seminar
FOR 5030	Advanced Forest Problems
FOR 6000	Research and Thesis

Research Interests:

I conduct research on water relations, carbon and nitrogen metabolism of forest plants and factors controlling vegetation dynamics. A major focus is water uptake and transfer in trees. The goal is to determine the relations between root morphology and anatomical structures and hydraulic properties of pine and oak. For example, what is the role of passage cells in the endodermis and pine and oak and the exodermis of oak? I am cooperating with Roland Huc (INRA, Avignon , France ) in a comparison of xylem efficiency and vulnerability to cavitation in overstory Pinus and understory Quercus and Buxus in Mediterranean forests. The oak savanna of Oklahoma is under study in cooperation with David Stahle ( U. of Arkansas ) to learn how land use changes affect vegetation dynamics.

Honors and Awards
Sabbatical Leave with INRA (French National Institute for Agronomic Research) Avignon , 2001 Editor-in-Chief of New Forests, 1994-present Scientific Board, Annals of Forest Science, 1990-present Fulbright Senior Scholar, 1993, Lehrstuhl für Pflanzenökologie, Universität Bayreuth , Germany IUFRO Shoot Growth Physiology Working Party S2.01.11, Co-Chair Registered Professional Forester, Oklahoma

Professional Memberships
Society of American Foresters Physiology Working Group C6 Oklahoma Academy of Science

Current Graduate Students
MS
	Laxman Karki, Forest Resources Management, Dynamics of oak regeneration in cross timbers forests

Recent Publications (since 2000)

Clark , S., Hallgren, S. W., Lynch, T. B. and Stahle, D. W., 2005. Characteristics of the Keystone Ancient Forest Preserve, an old-growth forest in the Cross Timbers of Oklahoma. Natural Areas J. In Press.

Clark, S. and Hallgren, S.W. 2004. Age estimation of Quercus marilandica and Q. stellata: applications for interpreting stand dynamics. Can. J. For. Res. 34:1353-1358.

Hallgren, S. W. 2004. Tree physiology: shoot growth and canopy development. In Encyclopedia of Forest Sciences. Eds. J. Burley, J. Evans, and J. A. Youngquist. Academic Press, London . Pp. 1600-1606.

Clark, S. and Hallgren, S.W. 2004. Can oak seedlings be aged from bud scars. Southwest. Nat. 49:243-246.

Clark, S. and Hallgren, S.W. 2003. Dynamics of oak (Quercus marilandica and Q. stellata) reproduction in an old-growth cross timbers forest. Southeastern Naturalist. Southeastern Naturalist 2:559-574.

Wu, L., Hallgren, S. W., Huang, Y., Conway, K. E. And Tauer, C. G. 2003. Storage protein mobilization and thiol protease up-regulation by solid matrix priming in loblolly pine (Pinus taeda) seed embryos. Seed Science and Technology 31:667-680.

Enstone, D.E. , C.A. Peterson, and S.W. Hallgren. 2001. Anatomy of seedling roots of loblolly pine (Pinus taeda L.). Trees - Structure and Function 15:98-111.

Committees
Forestry Graduate Education Committee, Chair DASNR International Program Advisory Committee, Member Plant Sciences Program Steering Committee, Member CASNR Environmental Sciences Undergraduate Program Steering Committee, Member