Linking woody plants, climate, and evapotranspiration in a temperate savanna

Olariu, Horia G.; Wilcox, Bradford P.; Popescu, Sorin C.

doi:https://doi.org/10.5194/hess-29-4825-2025

Articles | Volume 29, issue 19

https://doi.org/10.5194/hess-29-4825-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/hess-29-4825-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 29, issue 19

Research article

|

30 Sep 2025

Research article |

| 30 Sep 2025

Linking woody plants, climate, and evapotranspiration in a temperate savanna

Horia G. Olariu, Bradford P. Wilcox, and Sorin C. Popescu

Data sets

MODIS16 ET product Running et al. https://doi.org/10.5067/MODIS/MOD16A2GF.061

Daymet V4 Temperature and Precipitation product Thornton et al. https://doi.org/10.3334/ORNLDAAC/1840

Canopy Cover product Rangeland Analysis Platform / USDA https://rangelands.app/rap/?biomass_t=herbaceous&ll=36.5526,-101.3460&z=4&landcover_t=tre

2020 Canopy Height Product Malambo and Popescu, 2024 / Texas A&M University https://lasers.tamu.edu/ice-cloudand-land-elevation-satellite-icesat-2-applications/

2019 Canopy Height Product Potapov et al, 2022 / University of Maryland, College Park https://glad.umd.edu/dataset/gedi

Runoff Product USGS https://waterwatch.usgs.gov/index.php?id=romap3&sid=w__download

Model code and software

Woody coverage code H. G. Olariu https://code.earthengine.google.com/08f4a2fdce7672cb261f48fc658850e2

Subbasin ET and Precipitation code H. G. Olariu https://code.earthengine.google.com/c77b2aeb8fc4687677b33c1c141d16bc

ET, Precipitation, and excess water analysis code H. G. Olariu https://code.earthengine.google.com/80ef181f4002d7314a10ae391800189d

Terrestrial aggregation code H. G. Olariu https://code.earthengine.google.com/8b4ee77f99b3e067bae38c8386e150ff

Pointwise sampling code H. G. Olariu https://code.earthengine.google.com/1957d01209128479a368e655b5b75064

Monthly MODIS ET code H. G. Olariu https://code.earthengine.google.com/2c21005c469551d5646b1ee86812cfe9

Monthly Precipitation and Temperature code H. G. Olariu https://code.earthengine.google.com/23bc61414ed99bb58892ea682a965b5e

Short summary

Satellite data reveal that woody plants in Texas’s Post Oak Savannah now return almost all rainfall to the atmosphere. In drier regions, once trees and shrubs blanket more than 80 % of the land, yearly water loss to the atmosphere even surpasses rainfall, shifting the region from a water surplus to a deficit and shrinking groundwater recharge. Without brush control, warming and further canopy growth could leave soils drier, streams weaker, and local water supplies increasingly strained.