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Phytotoxicity of salt and plant salt uptake: Modeling ecohydrological feedback mechanisms
Author(s) -
BauerGottwein Peter,
Rasmussen Nikolaj F.,
Feificova Dagmar,
Trapp Stefan
Publication year - 2008
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/2007wr006067
Subject(s) - phytotoxicity , transpiration , salinity , salt (chemistry) , environmental science , groundwater , chemistry , botany , biology , ecology , photosynthesis , geology , geotechnical engineering
A new model of phytotoxicity of salt and plant salt uptake is presented and is coupled to an existing three‐dimensional groundwater simulation model. The implementation of phytotoxicity and salt uptake relationships is based on experimental findings from willow trees grown in hydroponic solution. The data confirm an s‐shaped phytotoxicity relationship as found in previous studies. Uptake data were explained assuming steady state salt concentration in plant roots, passive salt transport into the roots, and active enzymatic removal of salt from plant roots. On the one hand, transpiration strongly depends on groundwater salinity (phytotoxicity); on the other hand, transpiration significantly changes the groundwater salinity (uptake). This feedback loop generates interesting dynamic phenomena in hydrological systems that are dominated by transpiration and are influenced by significant salinity gradients. Generic simulations are performed for the Okavango island system and are shown to reproduce essential phenomena observed in nature.