Experimental investigation of the responses of meadow buttercup (Ranunculus acris L.) to sodic salinity and its implications for habitat monitoring

Ranunculus acris L. is a native species widely distributed throughout Europe and is invasive in nonnative areas, causing substantial economic losses in pasture productivity. The present study examined the effects of sodic salinity on the growth and functioning of this species. Salinity stresses the germination process and seedling growth, indicating that the studied species experience serious limitations at 60–90 mmol dm(−3) NaCl and cannot establish in habitats where salinity is equal to or greater than 150 mmol dm(−3) NaCl. R. acris is tuned to subsaline habitats characteristic of temperate meadows, as its growth and functioning were the best when the plants were treated with 30 mmol dm(−3) NaCl. Increasing salinity (60 and 90 mmol dm(−3) NaCl) hampered growth, leaf morphology and photosynthesis but not mineral nutrition, as Na accumulation seemed to be the most outlined effect of NaCl application. Changes in leaf morphological characteristics coordinated well with Na content in those organs, which indicates that leaf appearance can be easily catchable sign of progressing salinity. Ultimately, progressing salinity reduces the competitiveness of the studied species, shifting its strategy to ruderal behavior, but under subsaline conditions, the strategy of this species seems to be most balanced.