Uptake, transport and seasonal recycling of 134Cs applied experimentally to bracken (Pteridium aquilinum L. Kuhn)

Solutions containing 134Cs were applied to cultivated clones of bracken. The radionuclide was taken up by roots, rhizome tips and leaf tips, and its subsequent retention and transport was monitored over a year. 134Cs was transported through growing plants, recycled down to rhizomes at the end of the growing season and concentrated in meristems and second generation leaves. Accidentally released 137Cs may therefore be taken up and recycled to succeeding generations of leaves in this important component of extensive upland and heathland ecosystems. The long-lived nature of bracken means that 137Cs could remain environmentally available for many years longer than its physical half-life (30.2 yrs) and concentration in meristems could potentially cause genetic and phenotypic change in clones.