The relations between trunk diameter fluctuations and tree water status in olive trees (Olea europea L.).

摘要

The seasonal evolution of maximum daily shrinkage (MDS) of olive (cv. Picual) tree trunks was characterized in an orchard (in Cordoba) where differences in water status were imposed by differential irrigation and with time of the year. The MDS-stemwater potential (PSI) relationship showed two different phases. Under conditions of mild water stress, a linear relationship between these two parameters was found with a high rate of increase in MDS values as PSI decreased. At about -1.5 MPa PSI, the relationship changed and a further reduction in PSI was associated with a decrease in MDS. In the period of recovery, the MDS values were less than those previously measured at the same level of PSI. The hysteresis in the PSI-MDS relationship could be an effect of stomatal behaviour.