HR: 0800h
AN: ED11C-0630    [Abstracts]
TI: Assessing the Function of Cypress Knees – A Watershed Watch Student Project
AU: * Harris, M D
EM: MDHARRIS@mail.ecsu.edu
AF: Elizabeth City State University, CERSER Dixon Hall, Elizabeth City, NC 27909, United States
AU: Rock, B N
EM: barry.rock@unh.edu
AF: University of New Hampshire, Leitzel Center Parsons Hall, Durham, NH 03824, United States
AU: Hale, S R
EM: steve.hale@unh.edu
AF: University of New Hampshire, Leitzel Center Parsons Hall, Durham, NH 03824, United States
AU: Hayden, L B
EM: haydenl@mindspring.com
AF: Elizabeth City State University, CERSER Dixon Hall, Elizabeth City, NC 27909, United States
AU: Porter, W
EM: waporter@mail.ecsu.edu
AF: Elizabeth City State University, CERSER Dixon Hall, Elizabeth City, NC 27909, United States
AB: The research presented was conducted as part of Watershed Watch, a two-week hands-on summer program for undeclared entry-level undergraduates, designed to recruit and retain students in Science, Technology, Engineering, and Mathematics (STEM) disciplines. The research presented here was conducted on cypress knees of different ages from the campus of Elizabeth City State University in northeastern North Carolina. Samples were collected from Bald Cypress (Taxodium distichum) knees and thin sections were cut from the distal, medial, and proximal regions of each knee. Three specimens of each of young and old knees were analyzed. Structural differences in the location and amount of wood (secondary xylem), parenchyma, and aerenchyma tissues were compared in order to determine if both younger and older knees function as pneumatophores, and if only the younger knees are capable of providing oxygen to roots in waterlogged soils. Our findings include: younger knees have the most aerenchyma tissue (living cells associated with air canals) and a thinner bark (likely pervious) on the distal tips. The older knees are more woody with distinct growth rings, exhibit less aerenchyma tissue, and have a much thicker (likely impervious) bark at the distal tip. The conclusion regarding the purpose of cypress knees is that the younger knees likely function as aerating organs (peumatophores) for the growing roots tips, while the older knees have reduced amounts of aerenchyma tissue and a thicker bark, and therefore may lose the ability to function as an aerating organ for the older roots.
DE: 0810 Post-secondary education
DE: 0850 Geoscience education research
SC: Education and Human Resources [ED]
MN: 2007 Fall Meeting