Element Mobility In Bald Cypress Xylem

Abstract

Trace element mobility in bald cypress (Taxodium distichum) was investigated for a suite of elements using cores from century-old trees from a wetland in Humphreys County, Mississippi. Element mobility was determined by comparing the dendrochemistry of decadal increments over the life span of a tree, and by comparing increments of the same age collected from the same tree during two different seasons. Variability within growth increments at the time of sampling was evaluated by comparing cores from the same tree collected at three points around the bole. Of 42 elements analyzed, eight were found above detection limits (As, Ca, K, Mg, Mn, Na, P, Zn). Clear evidence of translocation of P and Mn to the sapwood and K, Mg, and Na to the heartwood was observed. Ca and Zn were found with higher average concentrations in the sapwood, though evidence of translocation to the sapwood was equivocal. Arsenic did not vary significantly through any individual core. Variation in concentration was not found to be significant for any element with respect to year of sampling, season, location in the wetland, or position around the bole. With the exception of As, variation was significant with respect to increment age (decade) and location within the heartwood or sapwood.