Data from a drought experiment on Corylus avellana (Belgian and Spanish origin) and Corylus maxima (Belgian origin)

These data are gathered during a drought experiment on Corylus taxa. We follow: https://www.vlaanderen.be/inbo/normen-voor-datagebruik/ This is the abstract of the submitted manuscript: Background: "Understanding the mechanisms by which woody perennials adapt to extreme water deficits is important in regions experiencing increasingly frequent and intense droughts. Methods: We investigated the effects of drought severity in the shrubs Corylus avellana, C. maxima and their morphological intermediate forms, all from local Belgian origin, and C. avellana from a Spanish-Pyrenean origin. Potted saplings in a common garden setting were not receiving any water during 30 days in July 2021 and developed a range of visual stress symptoms. We assessed responses across the various symptom categories. Results: Droughted plants senesced later than the controls (up to 6 days), with the most severely affected plants displaying the largest delay (21 days). Severity of visual drought symptoms and delay in leaf senescence did not show a linear relation. However, the delay in leaf senescence was reflected in the subsequent bud burst which was delayed for the drought treated plants, with again the largest delay for the most severely affected plants. Interestingly, radial growth shifted towards the autumn among the drought treated plants, suggesting compensation growth after growing conditions normalized. The Spanish-Pyrenean provenance, characterized by smaller plants with smaller leaves, developed visual drought symptoms later than the local provenance during the drought. Conclusions: The results indicate that severe early summer drought, followed by rewatering, not only diminishes radial growth but also prolongs it in time, and delays leaf senescence, both influencing carbon sequestration. Provenances adapted to high altitudes may hold an advantage under water limiting conditions."