CORRELATION BETWEEN TERBIUM AND THE OTHER RARE-EARTH ELEMENT CONTENTSIN FERN LEAVES

The lanthanides (REEs) in 142 fern leaves collected from 9 sampling si tes in Japan were analyzed by instrumental neutron activation analysis . Between two REEs a strong positive correlation was found in the loga rithmic scattering diagram with correlation and regression coefficient s close to unity, suggesting neither selective accumulation by plants nor different availability from soil between the two elements. However , between Tb and the other REEs the relationship showed two lines with the same correlation coefficient. This suggested that there must be a difference in the availability of REEs or in their absorption charact eristics by plants. Further analysis revealed that the splitting was d ue to some difference in the environmental factors where the fern grew . However, the amount of REE in the soil collected together with the c orresponding fern did not reflect the REE concentration in the fern le aves.