Technical note: How well do evapotranspiration partitioning approaches perform in moss-covered wetlands?
- 1University of Waterloo (Waterloo, Canada)
Abstract
Evapotranspiration (ET) is the dominant hydrologic flux in wetlands, and partitioning into transpiration (T) and evaporation (E) is essential for understanding water and carbon dynamics, guiding sustainable water management practices, and predicting responses to climate change in these systems. However, the presence of moss layers and the dynamic hydrological condition in many wetlands challenges the assumptions of commonly used partitioning methods. This study evaluates ten eddy covariance (EC)-based ET partitioning approaches representing three methodological groups, namely high-frequency EC-based, ecosystem carbon-water coupling, and machine learning approaches, across four moss-covered wetlands in the boreal region and the Canadian Rocky Mountains. Evapotranspiration partitioning estimates were evaluated against independent measurement-based T : ET estimates derived from flux chambers, micro-lysimeters, sap flow sensors, and EC measurements, and against the ensemble mean of all ET partitioning approaches. Results showed that none of the evaluated approaches consistently outperformed the others across sites or under both flooded and non-flooded conditions, and no methodological group demonstrated a clear overall advantage. Evapotranspiration partitioning performance is likely influenced by the combined effects of multiple environmental and methodological factors, including moss cover, flooding conditions, canopy structure, ecosystem heterogeneity, EC measurement configuration and data quality, and the assumptions underlying each approach. In addition, the evaluation results are also influenced by the choice of reference dataset, which highlights the uncertainty associated with benchmarking ET partitioning methods. These findings suggest that applying multiple ET partitioning approaches concurrently, whenever possible, can help identify sources of uncertainty and potential errors. The study also highlights the need to develop wetland-specific ET partitioning approaches that better represent moss-mediated carbon uptake, dynamic carbon-water coupling, and transitions between unsaturated and flooded conditions.
Versions
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BibTeX
@article{wang2026technical,
title = {{Technical note: How well do evapotranspiration partitioning approaches perform in moss-covered wetlands?}},
author = {Yi Wang and Richard M. Petrone and Lei Zhang},
journal = {Biogeosciences},
year = {2026},
month = oct,
doi = {10.5194/bg-23-7067-2026},
url = {https://bg.copernicus.org/articles/23/7067/2026/},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Technical note: How well do evapotranspiration partitioning approaches perform in moss-covered wetlands?
AU - Yi Wang
AU - Richard M. Petrone
AU - Lei Zhang
PY - 2026
DA - 2026/10/08
JO - Biogeosciences
DO - 10.5194/bg-23-7067-2026
UR - https://bg.copernicus.org/articles/23/7067/2026/
AB - Evapotranspiration (ET) is the dominant hydrologic flux in wetlands, and partitioning into transpiration (T) and evaporation (E) is essential for understanding water and carbon dynamics, guiding sustainable water management practices, and predicting responses to climate change in these systems. However, the presence of moss layers and the dynamic hydrological condition in many wetlands challenges the assumptions of commonly used partitioning methods. This study evaluates ten eddy covariance (EC)-based ET partitioning approaches representing three methodological groups, namely high-frequency EC-based, ecosystem carbon-water coupling, and machine learning approaches, across four moss-covered wetlands in the boreal region and the Canadian Rocky Mountains. Evapotranspiration partitioning estimates were evaluated against independent measurement-based T : ET estimates derived from flux chambers, micro-lysimeters, sap flow sensors, and EC measurements, and against the ensemble mean of all ET partitioning approaches. Results showed that none of the evaluated approaches consistently outperformed the others across sites or under both flooded and non-flooded conditions, and no methodological group demonstrated a clear overall advantage. Evapotranspiration partitioning performance is likely influenced by the combined effects of multiple environmental and methodological factors, including moss cover, flooding conditions, canopy structure, ecosystem heterogeneity, EC measurement configuration and data quality, and the assumptions underlying each approach. In addition, the evaluation results are also influenced by the choice of reference dataset, which highlights the uncertainty associated with benchmarking ET partitioning methods. These findings suggest that applying multiple ET partitioning approaches concurrently, whenever possible, can help identify sources of uncertainty and potential errors. The study also highlights the need to develop wetland-specific ET partitioning approaches that better represent moss-mediated carbon uptake, dynamic carbon-water coupling, and transitions between unsaturated and flooded conditions.
SN - 1726-4189
ER -