Effect of daily salinity fluctuation on the intraspecific interactions of a euhalophyte (<i>Suaeda salsa</i>) along a salinity gradient

Abstract Heterogeneity of soil salinity is a prominent environmental characteristic in the intertidal zone estuaries, affecting plant growth and shift biotic interactions salt marsh. This study aims to examine interactive effects gradient fluctuations on intraspecific euhalophyte. We assessed impact daily fluctuating outcome by cultivating seeds Suaeda salsa (Chenopodiaceae) river sand. The experiment was conducted greenhouse with three treatments: (static salinity), (200 400 mmol L−1) planting densities (1, 2 4 plants/pot). First, height biomass plants were measured at both start end experiment. Then, indexes log response ratio S. analyzed. shifted from competition low facilitation high salinity, conspecific density strengthened intensities. Daily fluctuation did not significantly affect interactions, but have significant influence belowground biomass. Our results suggest that stress-gradient hypothesis may apply predicting variation relationship salt-tolerant species along gradient, magnitude this dependent. These findings help us understand how individuals populations euhalophyte respond natural or human modification conditions.