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Zhou J, Yang Y, Liu Q, Liang L, Wang X, Sun T, Li S, Gan L. Revisiting the hydrological legacy of revegetation on China's Loess Plateau using Eagleson's ecohydrological perspective. Sci Total Environ 2024; 929:172758. [PMID: 38670382 DOI: 10.1016/j.scitotenv.2024.172758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 04/23/2024] [Accepted: 04/23/2024] [Indexed: 04/28/2024]
Abstract
Revegetation has resulted in a trend of increasing vegetation greenness on the Chinese Loess Plateau. However, it remains unclear whether the regional vegetation coverage exceeds hydroclimatic limitations in the context of revegetation, and the hydrological effects of greening are controversial. Eagleson's optimality hypothesis can explain some of the hydrological effects on the Loess Plateau. Here, building on previous research, the geospatial vegetation states were estimated for pre- and post-revegetation periods on the Loess Plateau from 1982 to 2015 using Eagleson's ecological optimality theory. Additionally, a drought composite analysis approach was utilized to investigate the hydrological effects related to drought (including sensitivity and partitioning) under various vegetation states. It was found that revegetation increased the proportion of catchments in the equilibrium state and decreased the proportion in the disturbed state, owing to a wetter climate compared with the pre-revegetation period. Root-zone soil drought, driven by precipitation (P) deficit, asymmetrically triggered hydrological effects for both the pre- and post-revegetation periods, with reduced runoff (Q) for both periods and a decrease in evapotranspiration (ET) during the pre-revegetation period but an increase in ET during the post-revegetation period. Moreover, catchments in an equilibrium state exhibited lower sensitivity between ET and P, and more stable partitioning of ET with regards to P, compared with those in a disturbed state. These results underscore the theoretical framework that an equilibrium state is crucial for maintaining ecosystem ET. Our results highlight the necessity of considering the hydrologic regulation of vegetation states when assessing the hydrological effects of vegetation change.
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Affiliation(s)
- Jialiang Zhou
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China; Key Laboratory for Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Yuting Yang
- State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China
| | - Qiang Liu
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China; Key Laboratory for Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing 100875, China.
| | - Liqiao Liang
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China.
| | - Xuan Wang
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Tao Sun
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China; Key Laboratory for Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Shuzhen Li
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China; Key Laboratory for Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Luoyang Gan
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China; Key Laboratory for Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing 100875, China
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Stevenson JL, Birkel C, Comte JC, Tetzlaff D, Marx C, Neill A, Maneta M, Boll J, Soulsby C. Quantifying heterogeneity in ecohydrological partitioning in urban green spaces through the integration of empirical and modelling approaches. Environ Monit Assess 2023; 195:468. [PMID: 36918498 PMCID: PMC10014787 DOI: 10.1007/s10661-023-11055-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 02/23/2023] [Indexed: 06/18/2023]
Abstract
Urban green spaces (UGS) can help mitigate hydrological impacts of urbanisation and climate change through precipitation infiltration, evapotranspiration and groundwater recharge. However, there is a need to understand how precipitation is partitioned by contrasting vegetation types in order to target UGS management for specific ecosystem services. We monitored, over one growing season, hydrometeorology, soil moisture, sapflux and isotopic variability of soil water under contrasting vegetation (evergreen shrub, evergreen conifer, grassland, larger and smaller deciduous trees), focussed around a 150-m transect of UGS in northern Scotland. We further used the data to develop a one-dimensional model, calibrated to soil moisture observations (KGE's generally > 0.65), to estimate evapotranspiration and groundwater recharge. Our results evidenced clear inter-site differences, with grassland soils experiencing rapid drying at the start of summer, resulting in more fractionated soil water isotopes. Contrastingly, the larger deciduous site saw gradual drying, whilst deeper sandy upslope soils beneath the evergreen shrub drained rapidly. Soils beneath the denser canopied evergreen conifer were overall least responsive to precipitation. Modelled ecohydrological fluxes showed similar diversity, with median evapotranspiration estimates increasing in the order grassland (193 mm) < evergreen shrub (214 mm) < larger deciduous tree (224 mm) < evergreen conifer tree (265 mm). The evergreen shrub had similar estimated median transpiration totals as the larger deciduous tree (155 mm and 128 mm, respectively), though timing of water uptake was different. Median groundwater recharge was greatest beneath grassland (232 mm) and lowest beneath the evergreen conifer (128 mm). The study showed how integrating observational data and simple modelling can quantify heterogeneities in ecohydrological partitioning and help guide UGS management.
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Affiliation(s)
- Jamie Lee Stevenson
- Department of Geography, University of Aberdeen, Aberdeen, UK.
- Northern Rivers Institute, University of Aberdeen, Aberdeen, UK.
| | - Christian Birkel
- Department of Geography and Water and Global Change Observatory, University of Costa Rica, San José, Costa Rica
| | | | - Doerthe Tetzlaff
- IGB Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
- Geographisches Institut, Humboldt University Berlin, Berlin, Germany
- Northern Rivers Institute, University of Aberdeen, Aberdeen, UK
| | - Christian Marx
- IGB Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
- Water Resources Management and Modelling of Hydrosystems, Technische Universität Berlin, Berlin, Germany
| | - Aaron Neill
- Northern Rivers Institute, University of Aberdeen, Aberdeen, UK
| | - Marco Maneta
- Department of Geosciences, University of Montana, Missoula, USA
| | - Jan Boll
- Civil and Environmental Engineering, Washington State University, Pullman, WA, USA
| | - Chris Soulsby
- Northern Rivers Institute, University of Aberdeen, Aberdeen, UK
- Water Resources Management and Modelling of Hydrosystems, Technische Universität Berlin, Berlin, Germany
- Department of Ecohydrology, Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
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