Soil properties and their effect on water and mineral status of resurrection Ramonda serbica

Abstract

The resurrection flowering plant Ramonda serbica inhabits the shallow organo-mineral soil that develops in crevices on northern-facing carbonate rocks in the gorges in the Balkan Peninsula. This type of soil represents a complex substrate whose physical and chemical properties were found to be well suited to the most important requirements for the growth and development of R. serbica as well as for the plant’s survival in the state of anhydrobiosis in periods of drought stress. Considerable amount of organic matter (39.4%) in the soil resulted in the high field capacity (134 ml/100 g soil) as well as the slow changes in the amount of its available water. The suitable soil hydric status, based on the organic remains, supports the slow dehydration of this poikilohydric plant, which is extremely important in allowing the activation of the plant’s protective mechanisms. The pH of the soil solution was slighty alkaline (7.7) mostly due to carbonates in its crystallographic structure. The large amount of incompletely decomposed organic debris resulted in a marked difference between total and available nutrient concentration in the soil. Still, the adequate content of nutrients in the leaves points to efficient mineral consumption by the plant roots. The sufficient bioavailability of nutrients and water was also improved by vesicular–arbuscular mycorrhiza detected in R. serbica roots.