Low winter temperatures induce a disturbance of water relations in field olive trees

Abstract

Author contribution statement AL, OG, LT, FO and FJV designed the experiments. AL and OG carried out the fieldwork. AL, OG, LT, FO and FJV analyzed the data and prepared the manuscript. Conflict of interestNone. Key MessageLow winter temperatures induce an increase in the soil-to-trunk hydraulic resistance of field-grown olive trees resulting in a significant disturbance of their water relations. AbstractA disturbance of water relations in response to chilling have long been observed in potted plants growing under controlled conditions, but information is lacking for field plants. The aim of this study was to assess the effects of winter low temperatures on the water relations of mature olive trees. To this end, water potential, sap flux density, soil temperature and meteorological data were monitored in a hedgerow olive orchard near Córdoba, southern Spain, throughout two consecutive winters. Water stress symptoms were found in terms of midday Ψ despite adequate water supply and low evaporative demand. These effects were associated with changes in the soil-to-trunk hydraulic resistance (R root ), which increased by December-January to much higher values than those previously reported in the literature, particularly in the year of higher fruit load. The contribution of viscosity (η) to the observed R root dynamics was almost negligible as deduced from measurements of soil temperature, so the high winter values of R root were likely to have originated from other causes such as reductions in membrane permeability and root growth.The findings of this work raise new major issues that deserve further research such as the impact of the winter water stress on stomatal conductance and photosynthesis rates in mature olive trees.

The key factor limiting plant growth in cold and humid alpine areas also plays a dominant role in plant carbon isotope discrimination

“…However, the present study showed no significant interaction of temperature and soil water availability on plant Δ ( p = 0.674, Table 5 ). This result likely suggests that the disturbance of plant water relations by low temperature in the study areas is not significant as reported in previous studies ( Norisada et al, 2005 ; López-Bernal et al, 2015 ).…”

Variations in Leaf Morphological Traits of Quercus guyavifolia (Fagaceae) were Mainly Influenced by Water and Ultraviolet Irradiation at High Elevations on the Qinghai-Tibet Plateau, China

“…2; Körner, 2007;Thomas, 2011), such chilling conditions can increase water viscosity and reduce enzymatic activity, thereby inducing ), and leaf nitrogen concentration (Narea, g m -2 ) were extracted from Zhang et al (2005). Based on these sets of measurements, leaf nitrogen use efficiency (PNUE, μmol g -1 s -1 ) was calculated as Amax divided by Narea physiological water stress (Magnani and Borghetti, 1995;López-Bernal et al, 2015). We also noted significant bivariate correlations between MAT and leaf morphological traits (Table 3).…”

Remote Sensing Energy Balance Model for the Assessment of Crop Evapotranspiration and Water Status in an Almond Rootstock Collection

“…Therefore, as there were not significant differences between slopes, we cannot affirm that these rootstocks have differences in the root hydraulic resistance ( R root ). In order to improve our understanding of the response of rootstocks to water stress, future studies should be able to determine the hydraulic resistances of different rootstocks through measurements of water potential gradients and transpiration ( López-Bernal et al, 2015 ). Differences in the intercept could be explained either due to still small differences in the canopy volume between rootstocks of group 2 or due to a physiological response related with an anisohydric or isohydric behavior.…”