MOVEMENT OF METALS TO NEW GROWING TISSUE IN THE MOSS HYLOCOMIUM SPLENDENS (HEDW) BSG

To obtain Hylocomium splendens (Hedw.) BSG. that varied in metal (K, M g, Ca and Zn) content, moss samples were collected from six sites arou nd a zinc contaminated area of Latvia; metal contents were artificiall y lowered by branch excision. The first fully expanded annual segment (mature segments), together with the unexpanded segment (juvenile segm ent) were grown in the laboratory with watering from below. The conten ts of K, Mg, Ca and Zn in new growth were correlated with initial cont ents in the juvenile + mature segments. However, the concentrations of these metals in the new growth were generally not correlated with tho se in the pre-experimental segments. The excision of branches from the mature segment favoured subsequent branch development in the young ju venile segment over further growth of the already expanded mature segm ent, but less new growth was observed when branches were excised. (C) 1997 Annals of Botany Company.