Temporal variations of isotopic compositions in gross rainfall, throughfall, and stemflow under a Japanese cedar forest during a typhoon event

Ikawa, Reo; Yamamoto, Takahiro; Shimada, Jun; Shimizu, Takanori

doi:10.3178/hrl.5.32

Cited by 28 publications

(46 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Xu et al () found both enrichment and depletion of TF δ 18 O relative to that of P g for a pine plantation and a native eucalyptus forest in South Australia. Isotopic fluctuations of TF corresponded to those of P g in a Japanese cedar forest and those of SF did not, which Ikawa et al () attributed to rainwater storage in the canopy and on stems as well as the mixing of incoming and stored water with different isotopic compositions. Soulsby et al () noted that the isotopic signature of TF generally showed little change relative to P g for a Scots pine ( Pinus sylvestris ) stand in Scotland, and SF was usually more enriched than either P g or TF .…”

Section: Discussionmentioning

confidence: 95%

“…The potential for changes in the isotopic composition of precipitation reaching the subcanopy environment has long been recognized (Gat & Tzur, ) and has been attributed to three main processes (Allen, Keim, Barnard, McDonnell, & Brooks, ; Brodersen et al, ): evaporation, isotopic exchange with atmospheric water vapour, and the selection process. Evaporation of intercepted water or the residence time of TF and SF in the canopy may enrich the isotopic composition of the latter fluxes compared with P g (Ikawa, Yamamoto, Shimada, & Shimizu, ). Isotopic exchange with atmospheric water vapour can engender enrichment or depletion of TF and SF relative to P g , although enrichment may be more likely (Saxena, ).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Importance of rainfall partitioning in a northern mixed forest canopy for soil water isotopic signatures in ecohydrological studies

Snelgrove

Buttle

Tetzlaff

2019

Hydrological Processes

View full text Add to dashboard Cite

The forest canopy can play a significant role in modifying the amount and isotopic composition of water during its passage throughout the near‐surface critical zone. Here, partitioning of gross rainfall into interception, throughfall, and stemflow and its implications for the amount and isotopic composition of soil water was studied for red oak, eastern white pine, and eastern hemlock trees in a northern hardwood‐conifer forest in south central Ontario, Canada. Stemflow production was greatest for red oak as a result of its upward‐projecting branches and least for eastern white pine due to its horizontal branches and rougher bark. These stemflow contributions to the near‐bole soil surface failed to produce consistently wetter soils relative to distal locations from the bole for all tree species. There was also no consistent evidence of isotopic enrichment of throughfall and stemflow relative to gross rainfall or of stemflow relative to throughfall for red oak or eastern hemlock. However, there was isotopic enrichment of both throughfall and stemflow for eastern white pine with increasing maximum atmospheric vapour pressure deficit, which may reflect the potential for evaporative fractionation as a result of retention and detention of water moving through the canopy by the rougher bark of this species. Dry soil conditions limited sampling of mobile soil water during the study, and there was no consistent evidence that either throughfall or stemflow fluxes controlled temporal changes in the isotopic signature of soil water beneath the tree. Thus, the potential for throughfall and stemflow fluxes in northern hardwood‐conifer forests to modify the isotopic composition of water taken up by the tree via transpiration remains an open question.

show abstract

Section: Discussionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Importance of rainfall partitioning in a northern mixed forest canopy for soil water isotopic signatures in ecohydrological studies

Snelgrove

Buttle

Tetzlaff

2019

Hydrological Processes

View full text Add to dashboard Cite

show abstract

“…Ikawa et al (2011) suggested that differences between the δ 18 O of throughfall and rainfall tended to disappear because the wetter the canopy becomes, the more flow paths are created, decreasing the lag time between rainfall and throughfall and reducing evaporation impact. The greater isotopic enrichment in throughfall at the beginning of the event was consistent with a dryer atmosphere with high vapour pressure deficit, suggesting that evaporation in the canopy at this initial stage of rainfall could be important, as corroborated by higher interception losses.…”

Section: Rainfall Intraevent Isotopic Modificationmentioning

confidence: 99%

Modification of the isotopic composition of rainfall by throughfall and stemflow: The case of Scots pine and downy oak forests under Mediterranean conditions

et al. 2018

View full text Add to dashboard Cite

Most hydrological studies based on stable water isotopes ( 18 O and D) use the isotopic composition of rainfall as input signal. Although stable water isotopes are conservative tracers, previous studies have shown that canopies modify the isotopic composition of rainfall. At present, there is a scientific agreement about the factors involved in isotopic modification, but the effect of each factor and the magnitude of the isotopic shift are still not clear. In this study, we analyse at an interevent and intraevent basis the spatio-temporal differences between the isotopic composition of rainfall, throughfall, and stemflow for two different species (Pinus sylvestris L. and Quercus pubescens Willd). The aim of the study is to analyse the isotopic modification that takes place in throughfall and stemflow and how meteorological variables and structural forest characteristics influence the observed changes. Rainfall and throughfall were sampled by a combination of bulk and sequential collectors, whereas stemflow was collected only by bulk collectors. Results showed that the isotopic modification occurred in both directions, although stemflow was consistently more enriched than throughfall. Despite the contrasting canopy structures, no significant differences between species were found. Moreover, the intraevent analysis suggested that all fractionation factors could occur during one event, but evaporation or isotopic exchange would have a higher impact at the beginning of rainfall, whereas canopy selection processes would be more important at the end of rainfall. Our results emphasize the importance of considering the isotopic composition of throughfall and stemflow in isotope-related studies in forested catchments.

show abstract

“…A few studies have measured paired TF and OP δ w at the sub‐event timescale, whether by sequential time increments or volumetric increments . Incremental TF δ w mostly tracks the temporal pattern of OP δ w but with slightly dampened variability . Temporal patterns of SF δ w , in contrast, have been much more temporally dampened .…”

Section: Canopy Processes and Their Isotopic Effectsmentioning

confidence: 99%

The role of stable isotopes in understanding rainfall interception processes: a review

Allen¹,

et al. 2016

View full text Add to dashboard Cite

The isotopic composition of water transmitted by the canopy as throughfall or stemflow reflects a suite of processes modifying rainfall. Factors that affect isotopic composition of canopy water include fractionation, exchange between liquid and vapor, and selective transmittance of temporally varying rainfall along varying canopy flowpaths. Despite frequent attribution of canopy effects on isotopic composition of throughfall to evaporative fractionation, data suggest exchange and selection are more likely the dominant factors. Temporal variability in canopy effects is generally consistent with either exchange or selection, but spatial variability is generally more consistent with selection. However, most investigations to date have not collected data sufficient to unambiguously identify controlling processes. Using isotopic data for improved understanding of physical processes and water routing in the canopy requires recognizing how these factors and processes lead to patterns of isotopic variability, and then applying this understanding toward focused data collection and analysis. WIREs Water 2017, 4:e1187. doi: 10.1002/wat2.1187 This article is categorized under: Science of Water > Methods

show abstract

Temporal variations of isotopic compositions in gross rainfall, throughfall, and stemflow under a Japanese cedar forest during a typhoon event

Cited by 28 publications

References 24 publications

Importance of rainfall partitioning in a northern mixed forest canopy for soil water isotopic signatures in ecohydrological studies

Importance of rainfall partitioning in a northern mixed forest canopy for soil water isotopic signatures in ecohydrological studies

Modification of the isotopic composition of rainfall by throughfall and stemflow: The case of Scots pine and downy oak forests under Mediterranean conditions

The role of stable isotopes in understanding rainfall interception processes: a review

Contact Info

Product

Resources

About