Sea water flood resilience of five plant species with conservation status over the Bulgarian Black Sea Coast

The Bulgarian Black Sea coastal zone is relatively protected from sea floods. Only extreme meteorological events such as unusual storms can cause flooding of coastal areas. Crucial for the application of rapid methods for vulnerability assessment of coastal plant communities from flooding caused by unusual storms over the Bulgarian Black Sea Coast is to obtain experimental data for sea water flood resilience. This study aims to determine the plant species survival in simulated flooding experiments in order to identify sea water flood resilience of five plant species with conservation status: Centaurea arenaria M. Bieb. ex Willd., Crambe tataria Sebeok, Aurinia uechtritziana (Bornm.) Cullen & Dudley, Silene thymifolia Sm., and Stachys maritima Gouan. As a result of a simulated flooding experiment, Critical Decomposition Time (CDT) was obtained. The five species were within the most vulnerable group (CDT < 48 h). The CDT was significantly shorter than floods with a maximum duration for the Bulgarian Black Sea Coast. Only the values of the parameter beginning of decomposition of the leaves were accelerated by higher water temperatures. Other parameters were unrelated to different water temperatures. The investigated species have low survival rates and low degree of sea water flood resilience and their communities will not be able to recover after flooding with maximum duration within one vegetation season