Influence of Raindrop Size Distribution on Throughfall Dynamics under Pine and Birch Trees at the Rainfall Event Level

Abstract

Abstract:Part of precipitation is intercepted by forest canopies, while the rest reaches the ground as throughfall or stemflow. This process is influenced by various meteorological variables, of which we have mainly focused on drop diameter and velocity. Rainfall in the open and throughfall under birch and pine trees have both been measured since 2014 in Ljubljana, Slovenia. The results demonstrate that the total throughfall during 3.5 years was 73% and 53% of rainfall under birch and pine trees, respectively. During the 236 analysed events, the median volume diameter was 1.8 mm (±1.7 mm), and kinetic energy between 0.01 mJ/cm 2 and 23.3 mJ/cm 2 was recorded. We closely analysed the effect of rainfall microstructure on throughfall under pine and birch trees during three specific rainfall events. The increase in drop diameter and fall velocity during a rainfall event instantaneously increased throughfall under pine trees between 25% and 47%, whereas no such changes were observed under birch trees. This may be the consequence of different tree properties of the two species. Additionally, in the case of a saturated canopy, throughfall under pine trees exceeded rainfall in the open after an onset of larger and faster drops.

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

“…An analysis of factors that affect the S and wettability is of increasing interest to ecohydrologists [8,29,[50][51][52][53]. However, the mechanism of the adherence of water to the plant material is not yet fully understood [8,9,54].…”

Influence of Rainfall on Canopy Interception in Mixed Broad-Leaved—Korean Pine Forest in Xiaoxing’an Mountains, Northeastern China

“…Under dry conditions, interception rates are primarily controlled by rainfall intensity [14]. Although rainfall characteristics were considered to be the most influential variables, the number of raindrops, raindrop diameter, and velocity were hardly included in the analyses of rainfall effects on canopy interception [15][16][17], except for in a study by Zabret et al [17], who reported that raindrops with a larger diameter (6.5-8.5 mm) and higher velocity (7.6-10.4 ms −1 ) reduced canopy interception of rainfall.…”

Characterization of differential throughfall drop size distributions beneath European beech and Norway spruce

“…Forest canopies intercept incident rainfall and thus change the rainfall distribution and its amount (Crockford & Richardson, ); consequently, their TF DSD differs from open precipitation (Hall & Calder, ). With the advent of optical disdrometers, a number of studies have begun to examine the effects of meteorological conditions, canopy structure, and the role of plant surfaces on TF DSD (e.g., Frasson & Krajewski, ; Hall & Calder, ; Nanko, Hotta, & Suzuki, ; Nanko, Hudson, & Levia, ; Nanko, Watanabe, Hotta, & Suzuki, ; Zabret, Rakovec, Mikoš, & Šraj, summarized in Levia et al, ). These studies investigated the following species: Zea mays L.(maize; Frasson & Krajewski, ), Pinus caribaea Morelet (Caribbean pine) , Eucalyptus camaldulensis D. (river red gum), and Tectona grandis L. F. (Teak; Hall & Calder, ) as well as Chamaecyparis obtusa (Siebold & Zucc.)…”