Analysis of the characteristics of some populations of Crambe tataria Sebeók from Romania

Crambe tataria is a perennial species in the Brassicaceae family considered currently threatened. The identified causes of the decline of this species are overgrazing, use of fertilizers, mowing, invasive species, fires, abandonment of pastoral systems, artificial planting, agricultural and forestry activities, as well as recreational activities. In Romania, the species is declining due to overgrazing. The study aimed was to identify and describe the relationships between population characteristics and some environmental variables. Moreover, for the evaluation of the edaphic conditions of the populations of C. tataria, soil samples were collected and analyzed. The characteristics of the populations that were recorded in the plots of 100 m2 were represented by morphological variables (the habitus of the species, the size of the leaves, and the flowering) and demographic variables (the proportion of flowering individuals and number of individuals/plot). Habitat characteristics were represented by topographic, climatic, soil chemical, anthropogenic data, and the structural characteristics of plant communities. The relationships between population characteristics and environmental variables were evaluated using generalized linear models (GLMs). A multivariate analysis (Principal Component Analysis) was performed. The results obtained showed that soil chemical variables are the best predictors of the characteristics of C. tataria populations. Analysis of the characteristics of C. tataria populations indicates that 80% of the populations present good status, 13.33% of the populations present poor status, and 6.66% of the populations present bad status. However, the decrease in population size and the proportion of individuals flowering in the regions of Transylvania and Muntenia indicate the establishment of active protection strategies. •The characteristics of the populations of C. tataria indicate a good status for most of the analyzed populations.•The populations of Crambe tataria in Romania are declining due to overgrazing.•The soil chemical variables are the best predictors of the characteristics of C. tataria populations.•Demographic variables of C. tataria populations are mainly influenced by vegetation height and cover.•Morphological variables of C. tataria populations were mainly influenced by silicon, lead, pH, and calcium.