Variability in the Wettability and Water Storage Capacity of Common Oak Leaves (Quercus robur L.)

Abstract

Abstract:The canopy water storage capacity and wettability of the plant material are significantly dependent on the condition of the leaf surface. The aim of the present research was an analysis of the influence of infection with oak powdery mildew, seasonal changes occurring on leaves and factors related to location on the surface of leaves and their hydrological properties. This study performed a series of experiments connecting the direct spraying of tree branches with simulated rainfall under laboratory conditions; an analysis of the content of aromatic hydrocarbons in leaves with the use of the chromatograph; and measurements of the angles of adherence of raindrops to the leaf surface. Degree of wettability was determined and, additionally, photographs were taken with a scanning electron microscope. The experiments were performed on common oak (Quercus robur L.) both in the city and in the forest, on two dates: in May and September. All series of measurements were done on healthy leaves and on leaves covered with oak powdery mildew (Microsphaera alphitoides Griff. et Maubl.) to various degrees. Oak powdery mildew has the largest influence on the canopy water storage capacity and on hydrophobicity. In September, the leaves retained an average of 7.2 g/g more water than in May; and, in the leaves from the city, the canopy water storage capacity was 3.1 g/g higher. A decreasing angle of inclination of raindrops to leaves testified to growing wettability and increased the amount of water retained in tree crowns. An additional analysis of SEM photographs points to a dependency of the canopy water storage capacity on the condition of the surface of leaves.

How Characteristics of a Rainfall Event and the Meteorological Conditions Determine the Development of Stemflow: A Case Study of a Birch Tree

“…A significantly higher stemflow during the leafless rather than in the leafed period was observed also in other studies (André et al, 2008;Šraj et al, 2008;Zabret et al, 2017;Zabret and Šraj, 2019). However, leaf wettability and water storage capacity are also varying with seasons (Klamareus-Iwan and Witek, 2018). Additionally, Iida et al (2017) showed that not only the phenophase but also the length of the event and its period (i.e., the first and the second half of the event development) influenced the response of stemflow.…”

Spatial and Temporal Variability of Throughfall among Oak and Co-Occurring Non-Oak Tree Species in an Upland Hardwood Forest

“…Growth strategies and physiology determine leaf life span [45,46], so it is reasonable to hypothesize that these attributes differ between species and will impact throughfall. Additionally, coatings on leaf surfaces change throughout the growing season, such that leaf hydrophobicity decreases as leaves age, increasing interception storage capacity, thus reducing throughfall [47]. Had this study been able to sample at shorter-time intervals, differences in phenoseasons beyond leaf-on vs. leaf-off canopy phase may have been expressed more strongly and led to periods during the year when throughfall was even more different among species.…”

Effect of Plant Morphological Traits on Throughfall, Soil Moisture, and Runoff

“…It can be inferred that the more fragmented leaf and higher stem density (Table 2) are the dominant contributors to the smaller throughfall depth. Compared with a more compact leaf, a fragmented leaf enhances water adhesion capacity [11], which promotes surface evaporation due to a large wet surface area [15], by preventing the formation of large droplets [29] and generating smaller droplets by splashing. Smaller droplets evaporate quickly and reduces throughfall [31].…”

“…In addition, exploring the role plant morphology traits play is of particular importance in interpreting the variation of interception storage capacities among ecosystems [7]. Firstly, plant morphology traits affect the capacity of the canopy to intercept rainfall [11,[14][15][16]. For example, small, light, soft, and noncircular leaves, densely situated on small branches, have more effective water adhesion capacity [11].…”