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.
Original language | English |
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Article number | 468 |
Number of pages | 26 |
Journal | Environmental Monitoring and Assessment |
Volume | 195 |
Issue number | 4 |
Early online date | 15 Mar 2023 |
DOIs | |
Publication status | Published - 15 Mar 2023 |
Bibliographical note
AcknowledgementsWe are grateful to the Leverhulme Trust ISOLAND project (RPG-2018-375) for funding. Furthermore, we are grateful to the Cruickshank Botanical Garden staff led by Mr Mark Paterson for support in creating and maintaining the study site. We thank Jonas Freymuller for help with setting up the sapflux sensors and David Dubbert for assistance with the isotope analysis. Finally, we thank the Aberdeen MSc Geophysics students for contribution to geophysical data collection.
Funding
This study was funded by Leverhulme Trust ISOLAND project (RPG-2018–375).
Funding Information:
This study was funded by Leverhulme Trust ISOLAND project (RPG-2018–375).
Publisher Copyright:
© 2023, The Author(s).
Keywords
- Urban ecosystem services
- Water balances
- Ecohydrological modelling
- Precipitation partitioning
- Infiltration
- Evapotranspiration