Isotopic response of run‐off to forest disturbance in small mountain catchments

Abstract

Stable water isotopes were applied to trace hydrological processes in an undisturbed (mature spruce forest) and a nearby disturbed (deforested from a bark beetle outbreak) lake catchments in the Czech Republic. Both catchments are situated above 1,000 m a.s.l. within the Šumava National Park and have similar environmental conditions. The isotopic compositions of precipitation, creeks, springs, and lakes were sampled at 3-week intervals over one hydrological year. Water inputs to catchments were derived from isotopically similar local precipitation, whereas run-off was found to have different isotopic signatures. Creeks in the undisturbed catchment had 1‰ and~7‰ higher δ 18 O and δ 2 H with~2‰ lower d-excess than in the disturbed catchment. The d-excess in creeks of the undisturbed catchment was more pronounced, particularly during snowmelt, and highly heterogeneous as compared with the disturbed catchment. Creeks in the undisturbed catchment were mainly fed by precipitation during the warm period (May-October), whereas creeks in the disturbed catchment were mostly fed by precipitation during the cold period (November-April).Estimated mean transit times of creeks and springs were~6 months, except for two creeks in the undisturbed catchment, which had residence times of~1 year. Although evaporation and transpiration fluxes were apparently reduced in the disturbed catchment, transpiration ratios were similar for both catchments. The difference in isotope signatures between catchments was attributed to the altered role of the forest canopy in temporal water distribution, which produced changes in the water cycle, potentially influencing important biogeochemical processes.

Speleothem Records from the Eastern Part of Europe and Turkey—Discussion on Stable Oxygen and Carbon Isotopes

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Evaporation in Mediterranean conditions: Estimations based on isotopic approaches at the watershed scale

“…An isotope‐enabled water balance approach is an alternative to direct measurements, and enables partitioning the evaporation component of the ET flux at the watershed scale (Gibson et al, 1993; Gonfiantini, 1986; Jasechko et al, 2013; Telmer & Veizer, 2000; Vystavna et al, 2018). This approach is cost‐effective in comparison to direct hydrological measurements and can be applied at a variety of scales, from a small watershed to a subcontinental river basin worldwide (e.g.…”

Stable H and O isotope-based investigation of moisture sources and their role in river and groundwater recharge in the NE Carpathian Mountains, East-Central Europe

“…Climate-driven patterns in the stable isotope distribution of oxygen and hydrogen in regional air masses across Europe are well understood, and these can be locally applied to distinguish between different moisture sources and tracks, to apportion seasonal contributions of various recharge sources to rivers and/or groundwater [16], and to identify and potentially quantify post-precipitation processes (e.g. evaporation) [17], etc. So far, only two studies have demonstrated this approach in Romania [18,19].…”