Document: LOU-3-31-16

Fine root tissue composition and morphology among fast- and slow-growing tree species of the Northeastern United States.

COMAS, L.H.*, L.P.TROAST, S.REED and D.M.EISSENSTAT

Pennsylvania State University, University Park, PA 16802 USA ¹

Abstract:
One of the least investigated components of woody plants is the fine root system. Woody plants expend a sizable quantity of carbon for root function and growth, and release large amounts of carbon into forest soil through the root system. Roots can add as much or more organic matter to forest soils than leaf litter. Despite their important role in plant carbon budgets and carbon cycling, there is little information available on fine root characteristics of tree species. Identifying suites of characters associated with growth forms is important for understanding the functional role of these plant forms in controlling community and ecosystem level processes. We examined fine root phenolic and nitrogen concentrations, root diameter, specific root length (SRL), specific surface area (SSA), and specific tissue density in 19 tree species native to the Northeastern US. Root material was collected in June and July 1999 from a mature forest stand in central Pennsylvania. In general, preliminary examination of the data showed that phenolic concentration tended to decrease as tree growth rate increased among the species (R² = 0.260). Among broad-leaf ectomycorrhizal species, this relationship was slightly stronger (R² = 0.340). Overall, nitrogen concentration tended to increase as tree growth rate increased (R²= 0.174). Variation in root morphology characteristics among species in most cases could not be explained by differences in tree growth rate, although SRL and SSA tended to increase as tree growth rate increased, especially among broad-leaf ectomycorrhizal species (R² = 0.220 and 0.258, respectively).

Keywords: Fine roots, SRL, root morphology, root phenolics, root N concentration

This abstract is being presented at: 3:30 PM in session:
ROOT PROCESSES