Seasonal dynamics of biomass and nutrients in Hepatica nobilis

Abstract

Seasonal allocation of biomass and nutrients (N, P, K, Ca and Mg) to different above- and below-ground parts was investigated in Hepatica nobilis. Below-ground biomass accounted for 43 to 62%, of which a major part consisted of roots. In May-June, the biomass of current leaves increased rapidly. Generally, the concentrations of nutrients in different parts did not differ very much during the season, and were generally on a low or intermediate level, compared to deciduous herbs. Phosphorus conc. in rhizome and roots decreased significantly in spring, indicating a translocation of stored P to growth of leaves and inflorescences. There was an indication of translocation of N, stored during the winter in rhizome and roots, to growth of new leaves. In spring, there was a significant uptake of Mg from soil. Both roots and rhizome were very poor in K throughout the year, whereas the leaves were important sinks for K. The results did not show evidence of major seasonal translocation of nutrients from above-ground to below-ground organs, presumably due to the rapid expansion of new leaves as the old leaves senesced in spring. The leaf phenology of Hepatica nobilis is discussed, as is the terminology of the leaf life-span of this species.