A link in the study of chemical interference exerted by Empetrum hermaphroditum: Quantification of batatasin-III in soil solution

In the boreal forests of northern Sweden, the clonal dwarf shrub Empetrum h ermaphroditum dominates the ground layer vegetation in post-fire succession s by exerting strong inhibitory effects on other plant species. These inhib itory effects have been attributed to the high production of phenolic compo unds and in particular the dihydrostilbene, batatasin-III. In this study, w e further explore the potential chemical interference of E hermaphroditum t hrough the release of batatasin-III. In so doing, we first quantified batat asin-III in snowmelt, throughfall, and in E. hermaphroditum litter. Batatas in-III was also quantified in soil solution from underneath E. hermaphrodit um vegetation on three different occasions during one growing season. The c oncentrations were generally found to be highest in the soil solution from the litter layer, where it reached a maximum concentration of 353 +/- 26 ng batatasin-III/ml in August. Furthermore, the concentrations of batatasin-I II were found to decline with depth in the soil profile. There were importa nt temporal variations, with the highest concentrations of batatasin-III fo und in May and August. The lowest concentrations occurred in June. Our resu lts suggest that E. hermaphroditum releases batatasin-III from leaves and l itter in sufficient amounts to account for accumulation of batatasin-III in soil.