4.7 Article

Modelling temporal variability of in situ soil water and vegetation isotopes reveals ecohydrological couplings in a riparian willow plot

期刊

BIOGEOSCIENCES
卷 19, 期 9, 页码 2465-2485

出版社

COPERNICUS GESELLSCHAFT MBH
DOI: 10.5194/bg-19-2465-2022

关键词

-

资金

  1. Bundesministerium fur Bildung und Forschung [033W034A]
  2. Einstein Stiftung Berlin [EVF-2018-425]
  3. ISOLAND project of the Leverhulme Trust [RPG-2018425]

向作者/读者索取更多资源

The study investigates the water, energy, and biomass dynamics of soil and plants under willow trees in Berlin, Germany using stable water isotopes. The results show that willow trees have high water use through evapotranspiration, while grass has lower evapotranspiration. The use of in situ data aids in improving the model's capability to simulate xylem water sources and transport. The study is important for understanding water cycling in the critical zone.
The partitioning of water fluxes in the critical zone is of great interest due to the implications for understanding water cycling and quantifying water availability for various ecosystem services. We used the tracer-aided ecohydrological model EcH(2)O-iso to use stable water isotopes to help evaluate water, energy, and biomass dynamics at an intensively monitored study plot under two willow trees, a riparian species, in Berlin, Germany. Importantly, we assessed the value of in situ soil and plant water isotope data in helping to quantify xylem water sources and transit times, with coupled estimates of the temporal dynamics and ages of soil and root uptake water. The willows showed high water use through evapotranspiration, with limited percolation of summer precipitation to deeper soil layers due to the dominance of shallow root uptake (> 80 % in the upper 10 cm, 70 %-78 % transpiration/evapotranspiration). Lower evapotranspiration under grass (52 %-55 % transpiration/evapotranspiration) resulted in higher soil moisture storage, greater soil evaporation, and more percolation of soil water. Biomass allocation was predominantly foliage growth (57 % in grass and 78 % in willow). Shallow soil water age under grass was estimated to be similar to under willows (15-17 d). Considering potential xylem transit times showed a substantial improvement in the model's capability to simulate xylem isotopic composition and water ages and demonstrates the potential value of using in situ data to aid ecohydrological modelling. Root water uptake was predominately derived from summer precipitation events (56 %) and had an average age of 35 d, with xylem transport times taking at least 6.2-8.1 d. By evaluating isotope mass balances along with water partitioning, energy budgets, and biomass allocation, the EcH(2)O-iso model proved a useful tool for assessing water cycling within the critical zone at high temporal resolution, particularly xylem water sources and transport, which are all necessary for short- and long-term assessment of water availability for plant growth.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.7
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据