Vertical Root Distribution and Strontium Uptake of a Slash Pine Stand on a Florida Spodosol

Root length distribution of slash pine (Pinus elliottiiEngelm. var. elliottii) and associated understory vegetation was investigated for an Ultic Haplaquod in north‐central Florida. One‐third of the length of pine roots (<1 mm in diameter) was present in the argillic horizon below the 1 m depth. Slash pine taproots extended between 200 and 330 cm below the surface, (i.e., 1‐2.3 m into the argillic horizon). Slash pine roots were often found growing in large diameter, dead palmetto roots. Two‐thirds of the soil samples taken from the E horizon had all the pine roots growing in dead palmetto roots. Stable strontium (Sr) was placed in the argillic horizon and in the litter layer. Strontium concentration in the slash pine foliage increased 30 to 50% (depending on the age of the foliage sampled) when the argillic horizon was treated. There was no apparent Sr increase in needle tissue from spiking the litter layer. This effect was most likely due to the competition from associated vegetation.