Karatassiou Maria, Karaiskou Panagiota, Verykouki Eleni, Rhizopoulou Sophia
Laboratory of Rangeland Ecology, School of Forestry and Natural Environment, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
Department of Agriculture, Crop Production and Rural Environment, University of Thessaly, Fytokou St., 38446 Volos, Greece.
Plants (Basel). 2022 Apr 8;11(8):1013. doi: 10.3390/plants11081013.
In this study, leaf hydraulic functionality of co-occurring evergreen and deciduous shrubs, grown on Olympus Mountain, has been compared. Four evergreen species (, , and ) and four deciduous species (, , and ) were selected for this study. Predawn and midday leaf water potential, transpiration, stomatal conductance, leaf temperature and leaf hydraulic conductance were estimated during the summer period. The results demonstrate different hydraulic tactics between the deciduous and evergreen shrubs. Higher hydraulic conductance and lower stomatal conductance were obtained in deciduous plants compared to the evergreens. Additionally, positive correlations were detected between water potential and transpiration in the deciduous shrubs. The seasonal leaf hydraulic conductance declined in both deciduous and evergreens under conditions of elevated vapor pressure deficit during the summer; however, at midday, leaf water potential reached comparable low values, but the deciduous shrubs exhibited higher hydraulic conductance compared to the evergreens. It seems likely that hydraulic traits of the coexisting evergreen and deciduous plants indicate water spending and saving tactics, respectively; this may also represent a limit to drought tolerance of these species grown in a natural environment, which is expected to be affected by global warming.
在本研究中，对生长于奥林匹斯山上共生的常绿和落叶灌木的叶片水力功能进行了比较。本研究选取了四种常绿物种（、、和）以及四种落叶物种（、、和）。在夏季期间对黎明前和中午的叶片水势、蒸腾作用、气孔导度、叶片温度和叶片水力导度进行了估算。结果表明落叶灌木和常绿灌木采用了不同的水力策略。与常绿植物相比，落叶植物具有更高的水力导度和更低的气孔导度。此外，在落叶灌木中检测到水势与蒸腾作用之间存在正相关关系。在夏季水汽压差升高的情况下，落叶植物和常绿植物的季节性叶片水力导度均下降；然而，在中午时，叶片水势达到了相当低的值，但落叶灌木的水力导度高于常绿灌木。共存的常绿和落叶植物的水力特性似乎分别表明了水分消耗和节约策略；这也可能是这些生长在自然环境中的物种耐旱性的一个限制因素，预计它们会受到全球变暖的影响。
