Plants vs. Streams: Their groundwater-mediated competition at “El Morro”, a developing catchment in the dry plains of Argentina

The study analyzes the 'El Morro' catchment in Argentina, where the conversion of native forests to agriculture has led to rising water tables and the emergence of new streams. The authors identify five mechanisms of competition: plants taking water from streams via unsaturated uptake (mechanism 1), focalized saturated uptake in wetlands (mechanism 2), and distributed saturated uptake in forests (mechanism 3); and streams taking water from plants through streambed deepening (mechanism 4) and sediment deposition (mechanism 5). Findings indicate that while unsaturated uptake previously suppressed streamflow, current high water tables have made saturated uptake by forests and wetlands significant, though deepening streams are now actively reclaiming water by lowering local water tables.

• Over the last four decades, the El Morro catchment experienced a significant rise in groundwater levels, with an average increase of 3.06 meters per decade across 27 monitored wells.
• The rise in groundwater levels was most pronounced in the higher belt of the catchment, where levels climbed by an average of 4.83 meters per decade.
• The study identifies five mechanisms of water competition: plants use unsaturated uptake (1), focalized saturated uptake in wetlands/riparian zones (2), and distributed saturated uptake in the landscape matrix (3); conversely, streams use streambed deepening (4) and sediment deposition (5) to capture water.
• Caldén forests (Prosopis caldenia) demonstrate the ability to use groundwater even when water tables are deep (over 7 meters), causing diurnal fluctuations and seasonal depressions in the water table.
• Stream base flow exhibits a clear seasonal pattern, with lower flows during the rainy and warm season (December to April) due to increased groundwater uptake by plants.
• The total specific water yield at the catchment's closure point was estimated at 19 mm/y based on topographic area and 29 mm/y based on geometric area, representing approximately 3.3% of long-term average rainfall inputs.
• Streambed deepening (mechanism 4) has actively reduced plant water access, as evidenced by the drying of a wetland at site B following the carving of new incisions.
• Long-term remote sensing data (2000-2020) shows a decrease in greenness for croplands and sediment deposits, while forests and grasslands/pastures showed an increase in greenness.

APA

Jobb´agy, E., Lorenzo, S., P´aez, R., Buono, N., D´ıaz, Y., Marchesini, V., & Nosetto, M. (2020). Plants vs. Streams: Their groundwater-mediated competition at “El Morro”, a developing catchment in the dry plains of Argentina. Inter-American Institute for Global Change Research. https://iai.int/wp-content/uploads/2025/01/Plants-vs.pdf

Chicago

Jobb´agy, Esteban, Santiago Lorenzo, Ricardo P´aez, Nicol´as Buono, Y´esica D´ıaz, Victoria Marchesini, and Marcelo Nosetto. Plants vs. Streams: Their groundwater-mediated competition at “El Morro”, a developing catchment in the dry plains of Argentina. Inter-American Institute for Global Change Research, 2020. https://iai.int/wp-content/uploads/2025/01/Plants-vs.pdf.

Wikipedia

{{cite report |last1=Jobb´agy |first1=Esteban |last2=Lorenzo |first2=Santiago |last3=P´aez |first3=Ricardo |last4=Buono |first4=Nicol´as |last5=D´ıaz |first5=Y´esica |last6=Marchesini |first6=Victoria |last7=Nosetto |first7=Marcelo |title=Plants vs. Streams: Their groundwater-mediated competition at “El Morro”, a developing catchment in the dry plains of Argentina |publisher=Inter-American Institute for Global Change Research |date=28 September 2020 |url=https://iai.int/wp-content/uploads/2025/01/Plants-vs.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{jobbagy2020plants, author = {Jobb´agy, Esteban and Lorenzo, Santiago and P´aez, Ricardo and Buono, Nicol´as and D´ıaz, Y´esica and Marchesini, Victoria and Nosetto, Marcelo}, title = {{Plants vs. Streams: Their groundwater-mediated competition at “El Morro”, a developing catchment in the dry plains of Argentina}}, institution = {Inter-American Institute for Global Change Research}, year = {2020}, month = sep, url = {https://iai.int/wp-content/uploads/2025/01/Plants-vs.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }