Ecohydrological separation in a pair catchments covered with natural grassland and planted forestland on the Chinese Loess Plateau: Evidence from a one‐year stable isotope observation. Issue 12 (27th December 2022)

• Record Type: Journal Article
• Authors: Liu, Jinzhao; Jiang, Chong; Guo, Li; Hu, Jing
• Is Part Of: Hydrological processes. Volume 36:Issue 12(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-12-27
• Subjects: Chinese loess plateau -- ecohydrologic separation -- natural grassland -- planted forestland; Hydrology -- Periodicals; Hydrology -- Research -- Periodicals; Hydrologic models -- Periodicals; Hydrological forecasting -- Periodicals; 631.432
• DOI: 10.1002/hyp.14778
• Languages: English
• ISSNs: 0885-6087

Abstract

Abstract: Plantation and natural restoration has been practised on the Chinese Loess Plateau (CLP). However, how vegetation restorations affect ecohydrological processes remains unclear. Here, we investigated δ 18 O and δ 2 H values in rainwater/snow, soil mobile and less‐mobile water, and root/stem and leaf water under different vegetation covers in two neighbouring catchments (non‐woods from DZG‐Grassland, trees and understory from YJG‐Forestland) over 1‐year period. Soil mobile and less‐mobile water showed significantly distinct δ 18 O and δ 2 H values across months, but isotopic offsets between plant stems/roots and soil mobile and less‐mobile water (Δ 18 OM and Δ 18 OLM or Δ 2 HM and Δ 2 HLM ) were consistent across vegetation types. These results supported ecohydrological separation, with a dynamic exchange between soil mobile and less‐mobile water on the CLP. The widespread isotopic offsets existed in the contrasted catchments, challenging the prior assumption of no isotope fractionation during root water uptake in the most terrestrial plants. Difference in leaf water isotopes was non‐significant across vegetation types, indicating that leaf water transpiration varied less significantly with vegetation types. Comparisons of the isotopic ecohydrology between forestland and grassland will help elucidate the hydrological cycle on the CLP. Abstract : We investigated δ 18 O and δ 2 H values in rainwater/snow, soil mobile and less‐mobile water, and root/stem and leaf water under different vegetation covers in two neighbouring catchments over 1‐year period. Our results supported the ecohydrological separation, with a dynamic exchange between soil mobile and less‐mobile water on the Chinese Loess Plateau.