Daily sap flow rate as an indicator of drought avoidance mechanisms in five Mediterranean perennial species in semi-arid southeastern Spain

Abstract

Daily sap flow rate was determined in five Mediterranean species (Pinus halepensis, Quercus coccifera, Pistacia lentiscus, Erica multiflora, and Stipa tenacissima) under two slope aspects (north-and south-facing) in a semi-arid area (Alicante, SE Spain). Sap flow velocity was measured in January, May, August and October of two consecutive years (1998 and 1999) using the stem heat balance (SHB) method. Our results have demonstrated the effects of global radiation (R g ), vapour pressure deficit (VPD) on the sap flow velocity per unit of leaf area. Mean daily sap flow rates (Q md ) showed values between 0.001 and 0.202 g H 2 O cm -2 leaf area day -1 . Q md values were higher on the south-facing slope than on the north-facing slope. In most species, the Q md was higher in 1998 than in 1999 due to the higher soil water content, temperature and VPD in 1998. In all five species, a decrease in predawn leaf water potential was accompanied by a decrease in mean daily sap flow rates; nevertheless, the responses of the five species to water deficit conditions were different. In this context, we have linked the drought avoidance mechanisms of the different species through the combined use of daily sap flow rate and predawn leaf water potential under different water deficit conditions. We conclude that Pinus halepensis, Pistacia lentiscus and Erica multiflora show water-savers mechanisms to cope with drought, while Quercus coccifera and Stipa tenacissima show waterspenders mechanisms.

Effects of terracing on soil water and canopy transpiration of Pinus tabulaeformis in the Loess Plateau of China

“…Under water stress, species tend to adjust their water consumption to avoid reaching water potential values that could produce irreversible damage (Chirino et al, 2011). Depending on their drought avoidance mechanisms, species can be classified into water-spender or water-saver types (Chirino et al, 2011).…”

“…Depending on their drought avoidance mechanisms, species can be classified into water-spender or water-saver types (Chirino et al, 2011). In this context, P. tabulaeformis showed lower sap flux density under drier water conditions (Fig.…”

“…It is also central to the construction of an ecosystem-level water balance (Yang et al, 2009). Sap flow measurement can provide insights on environmental limitations and it yields results comparable with the estimates of water use for entire forest ecosystems (Chirino et al, 2011;Kumagai et al, 2014;Miyazawa et al, 2014). Previous studies have shown that sap flow characteristics vary with species and growth status, as well as with meteorological, environmental, and edaphic features (Brito et al, 2015;Du et al, 2011).…”

“…Plants in these areas tend to deepen and extend their root systems to exploit substantial quantities of soil water for transpiration (Chen et al, 2014c;Limousin et al, 2009). Meanwhile, stomatal closure is an important physiological process employed by plants to regulate water use and to prevent their hydraulic system from irreversible damage (Chirino et al, 2011). Sap flow reduction caused by stomatal closure is considered to be the preliminary response of canopy transpiration to water stress.…”

Identifying the relationships of climate and physiological responses of a beech forest using the Standardised Precipitation Index: a case study for Slovakia

“…Sap flow and transpiration as key indicators reflecting tree water status, play a major role in the research of drought impact on plants. At the same time, soil water availability and weather conditions were repeatedly identified as essential for tree growth and seasonal differences in stem circumferences (Chirino et al, 2011;Ježík et al, 2011;Konôpka et al, 2014).…”