Exploring the stemflow dynamics and driving factors at both inter‐ and intra‐event scales in a typical subtropical deciduous forest

Abstract

Numerous efforts have been made to understand stemflow dynamics under different types of vegetation at the inter-event scale, but few studies have explored the stemflow characteristics and corresponding influencing factors at the intra-event scale. An in-depth investigation of the inter-and intra-event dynamics of stemflow is important for understanding the ecohydrological processes in forest ecosystems. In this study, stemflow volume (F V), stemflow funnelling ratio (F R), and stemflow ratio (F %) from Quercus acutissima and Broussonetia papyrifera trees were measured at both inter-and intra-event scales in a subtropical deciduous forest, and the driving factors, including tree species and meteorological factors were further explored. Specifically, the F V , F R and F % of Q. acutissima (52.3 L, 47.2, 9.6%) were lower than those of B. papyrifera (85.1 L, 91.2, 12.4%). The effect of tree species on F V and F % was more obvious under low intensity rainfall types. At the inter-event scale, F V had a strong positive linear correlation with rainfall amount (G P) and event duration (D E) for both tree species, whereas F R and F % had a positive logarithmic correlation with G P and D E only under high-intensity, short-duration rainfall type. F R and F % were mainly affected by wind speed and the maximum 30-min rainfall intensity under low-intensity, longduration rainfall type. At the intra-event scale, for both tree species, the mean lag time between the start of rainfall and stemflow was the shortest under high-intensity, short-duration rainfall type, while the mean duration and amount of stemflow after rain cessation were the greatest under high-amount, long-duration rainfall type. The relationship between stemflow intensity and rainfall intensity at the 5-min interval scale also depended greatly on rainfall type. These findings can help clarify stemflow dynamics and driving factors at both inter-and intra-event scales, and also provide abundant data and parameters for ecohydrological simulations in subtropical forests.

Vertical Variability in Bark Hydrology for Two Coniferous Tree Species

“…The upper canopy's bark water storage will influence the generation of branchflows and throughfall drip points (Herwitz, 1987;Van Stan et al, 2021). Along the lower portion of the stem, bark water storage can influence the generation of stemflow (Zhang et al, 2021). To advance understanding of this topic, this study examines vertical variability in bark water storage capacity (and other hydrological parameters) for two common tree species {Norway spruce [Picea abies (L.) Karst.]…”

Inter- and intra-event rainfall partitioning dynamics of two typical xerophytic shrubs in the Loess Plateau of China

“…In addition, net rainfall could regulate vegetation physiological-metabolic processes through nutrient enrichment (Levia and Frost, 2003;Zhang et al, 2016;Van Stan et al, 2017;Tonello et al, 2021), ultimately affecting the carbon balance of ecosystems (Chu et al, 2018;Jia et al, 2016). In light of the important role of rainfall partitioning in regulating soil moisture and vegetation patch patterns, investigations of the rainfall partitioning dynamics are imperative for a better understanding of the soil-watervegetation relationships (Molina et al, 2019;Van Stan et al, 2020;H. Zhang et al, 2021).…”

“…In addition to the inter-event studies, a few intra-eventscale studies have been reported, which are essential for a better understanding of soil moisture distribution and the hydrological cycle in arid regions (Levia et al, 2010;Levia and Germer, 2015;Cayuela et al, 2018;H. Zhang et al, 2021).…”

Inter- and intra-event rainfall partitioning dynamics of two typical xerophytic shrubs in the Loess Plateau of China

“…In addition, net rainfall could regulate vegetation physiological metabolic processes through nutrient enrichment (Levia and Frost, 2003;Van Stan II et al, 55 2017), ultimately affecting the carbon balance of ecosystems (Chu et al, 2018;Jia et al, 2016). In light of the important role of rainfall partitioning in regulating soil water dynamics and vegetation patch pattern, investigations of the rainfall partitioning dynamics are imperative for a better understanding of the soil-water-vegetation relationships (Molina et al, 2019;Van Stan II et al, 2020;Zhang et al, 2021a). 60 Studies on rainfall partitioning have been broadly carried out in different climatic zones and various types of vegetation (Magliano et al, 2019a;Gordon et al 2020;Sadeghi et al 2020;Rivera and Van Stan II, 2020;Zhang et al, 2021b).…”

“…In addition to the inter-event studies, a detailed understanding of shrub rainfall partitioning dynamics at the intra-event scale is essential for better understanding of soil moisture distribution and the hydrological cycle in arid regions. To understand the temporal 90 fluctuations of shrub rainfall partitioning and its importance to hydrological processes, data with high temporal resolution are required (Levia et al, 2010;Levia and Germer, 2015;Cayuela et al, 2018;Zhang et al, 2021a). For instance, Zhang et al (2018) found that temporal heterogeneity of rainfall clearly affected the spatiotemporal dynamics of TF of C. korshinskii in arid area of northern China.…”