Floodwater depth effects on nitrogen and phosphorus partition in young willow plants during the post-stress period.

MOZO, IRINA; MONTEOLIVA, SILVIA; LUQUEZ, VIRGINIA M. C.

Rosario

Congreso; RAFV Conference 2023; 2023

SAFV

Flooding alters nutrient uptake by plants, but less is known about the effects once the stress period is over.  The aim of this work was to analyze the effects of flooding depth on N and P partition in young willows plants during the post-stress recovery period. We analyzed two commercial hybrid willow clones (Salix matsudana x S. alba): Agronales and Carapachay. Plants were grown in pots and experienced two flooding regimes: partial flooding (PF) and plants totally submerged in water (TS). Plants responses were analyzed after 21 days of flooding and at the end of a 28 days period of post-flooding recovery. After the flooding episode,N and P increased in the leaves of the PF treatment, but not in the TS treatment. Clone Agronales had a higher N and P foliar concentration than Carapachay. These differences persisted after the post -flooding recovery period. There were no differences in nutrient concentration in stems and roots of the PF treatment in any sampling date. Flooded plants in TS treatment increased both N and P in stems, but these differences did not persist after the 28 days recovery period. There were no differences in the amount of N and P in leaves and roots in the TS treatment. Willows plants totally submerged adopted a typical quiescence strategy, suppressing growth, while the PF plants grew in height during the stress episode. Floodwater depth affected N and P partition, their concentration increased in leaves in PF but not in the TS treatment. The plants of the TS treatment experienced a transient increase in stem nutrient concentration, that did not persist after the end of the stress episode. The  higher concentration in stems of TS could be simple accumulation because N and P are not used for growth during flooding, and not a consequence of an enhanced uptake by the plants. But the changes in nutrient concentration in leaves are likely part of a persistent acclimation response.