Assessment of Interactions Between Stomatal Conductance, Evapotranspiration, Carbon and Irrigated Soil Salinity
Abstract
Hydrological behavior and soil salinity are intricately linked in many agricultural environments. Fluxes of energy, water, and carbon dioxide are critical to the response of plants to soil salinity. A physically based plant water use model is developed to examine the problem of soil salinity as it relates to evapotranspiration and plant water uptake in an arid agricultural region. This model incorporates carbon dynamics and photosynthetic activity into the plant water use model, and examines the nonlinear manner in which plants respond to increased soil salinity. Higher soil osmotic pressure resulting from increased ionic presence increases the resistance to water flow through the plant; this change also impacts the assimilation of carbon dioxide through the stomatal opening. Canopy and ecosystem fluxes are now measured with such intensity as to allow comprehensive diurnal analysis of the effects of soil water and salt status on plant water, carbon, and energy fluxes. Initial results show that at higher salinity levels, non-linear and higher variable changes occur to stomatal conductance and evapotranspiration. Scaling these results to the daily or weekly level may be of great use to agricultural planners in their water management decisions.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2006
- Bibcode:
- 2006AGUFM.B41B0184R
- Keywords:
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- 0429 Climate dynamics (1620);
- 0466 Modeling;
- 1818 Evapotranspiration;
- 1842 Irrigation