Ecology of Teucrium species: Habitat related metal content dynamics

Abstract

The chapter reviews the available data about the effect of habitat related metal content on Teucrium chamaedrys and T. montanum (Lamiaceae). The study was focused on element concentrations in plant and soil samples, both on metalliferous and non-metalliferous soils. Metal concentrations varied depending on species and habitat type. The levels of elements in plant tissues from non-metalliferous localities were always lower, compared to those from metalliferous (serpentine) ones. None of the species could not hyperaccumulate metals although the metal concentration in some of them exceeded the range, which is naturally found in plants. Depending on the nickel accumulation, both analyzed species are classified as excluders. The level of tolerance was related to the amount of metals and their bioavailability in the soil. The metal concentrations for the toxic elements were above the permissible limits for the toxic elements, in both species. The populations of the studied species demonstrated some adaptations to the serpentine habitats related to their secondary metabolites and its morphology, which is known as ser-pentinomorphoses. As a result of the heavy metal profiles of the soils, significantly higher values and differences in the quantity of secondary metabolites were recorded in plant populations growing on serpentines compared to non-serpentine ones. Teucrium chamaedrys and T. montanum populations on metalliferous habitats, possess morphological differences in contrast of populations on non-metalliferous habitats.