Acer velutinum Bioss. (velvet maple) seedlings are more tolerant to water deficit than Alnus subcordata C.A. Mey. (Caucasian alder) seedlings

Drought stress is a major environmental factor limiting plant growth. Selection of drought-tolerant plants critical importance in vegetation restoration and forestation programs. Alnus subcordata Acer velutinum are two valuable, dominant, endemic species the Hyrcanian forests. There fast-growing significant diffuse-porous hardwood afforestation reforestation. One-year old seedlings both were exposed to four water shortage treatments (100, 75, 50 25% field capacity (FC) chosen as control, mild, moderate, severe) for 12 weeks. Thereafter, their morphological characteristics such height basal area, total organs biomass (root, stem, leaf), leaf area (LA), specific (SLA), ratio (LAR), well physiological biochemical relative content (RWC), chlorophyll, free proline malondialdehyde (MDA), superoxide dismutase (SOD) peroxidase (POD) activity measured. The results showed that when reduced availability, plants’ height, diameter, biomass, LA, LAR, RWC chlorophyll decreased, but concentration, MDA content, SOD, POD increased species. root shoot (R/S) mass (RMR) at FC A. subcordata, whereas no difference was found under drought treatments. SLA significantly 50% decreased compared control treatment. more RWC, POD, lower increase than moderate Therefore, appears possess better mechanism cope stress. tolerance may enhance its potential climatic adaptations drier conditions with ongoing change.