PHYSIOLOGICAL STRATEGIES FOR ADAPTATION TO ARIDITY IN XEROPHILIC ECOSYSTEMS FROM "CRACU GAIOARA" BOTANICAL RESERVE (MEHEDINȚI COUNTY - ROMANIA)

Abstract

The Cracu Găioara Botanical Reserve is located on the left bank of the Danube, upstream from Drobeta-Turnu-Severin, within the administrative boundaries of the Dudașu Schelei commune, Mehedinți County. Although relatively small, the reserve hosts several rare species of European interest. The calcareous substrate, south-western exposure, and particular microclimatic conditions have facilitated the establishment of species with a sub-Mediterranean character. Ephedra distachia, a thermophilic relic, finds suitable habitat conditions here and is physiologically well adapted to aridity. Centaurea atropurpurea, another rarely taxon, exhibits physiological features characteristic of calciphilous and xerophilous plants. The accumulation of osmoprotective compounds-primarily carbohydrates-help stabilize proteins and maintain cellular turgor during prolonged periods of drought. Additionally, the low stomatal conductance values confer protection by reducing water loss under conditions of elevated evaporative demand.