Hydraulic redistribution by two semi-arid shrub species: implications for Sahelian agro-ecosystems

  • Authors: Kizito, F.; Dragila, M.I.; Sene, M.; Brooks, J.R.; Meinzer, F.C.; Diedhiou, I.; Diouf, M.; Lufafa, A.; Dick, R.P.; Selker, J.; Cuenca, R.
  • Publication Year: 2012
  • Publication Series: Scientific Journal (JRNL)
  • Source: Journal of Arid Environments. 83: 69-77

Abstract

Hydraulic redistribution is the process of passive water movement from deeper moist soil to shallower dry soil layers using plant roots as conduits. Results from this study indicate that this phenomenon exists among two shrub species (Guiera senegalensis and Piliostigma reticulatum) that co-exist with annual food crops in Sahelian agro-ecosystems. Real-time measurements were conducted for soil water content, soil water potential and microclimate variables notably; air temperature, relative humidity, wind speed, precipitation and solar irradiance. Additionally, sap flow measurements were conducted in shrub roots using the thermal dissipation technique on intact and coppiced shrubs. Monthly predawn leaf water potential was measured using a portable pressure chamber. During the peak of the dry season, both positive (toward shrub) and negative (toward soil) flows were observed in lateral shrub roots with sap flow in the lateral roots frequently negative at night and rapidly becoming positive soon after sunrise. The negative sap flow at night in superficial lateral roots and the periodic positive flow in the descending tap roots were indicative of hydraulic redistribution. Hydraulic redistribution may be an important mechanism for drought stress avoidance while maintaining plant physiological functions in both shrubs and neighboring annuals in water-limited environments.

  • Citation: Kizito, F.; Dragila, M.I.; Sene, M.; Brooks, J.R.; Meinzer, F.C.; Diedhiou, I.; Diouf, M.; Lufafa, A.; Dick, R.P.; Selker, J.; Cuenca, R. 2012. Hydraulic redistribution by two semi-arid shrub species: implications for Sahelian agro-ecosystems. Journal of Arid Environments. 83: 69-77.
  • Keywords: agro-ecosystems, annual food crops, hydraulic redistribution, Sahel, shrubs
  • Posted Date: October 5, 2012
  • Modified Date: June 2, 2014
  • Print Publications Are No Longer Available

    In an ongoing effort to be fiscally responsible, the Southern Research Station (SRS) will no longer produce and distribute hard copies of our publications. Many SRS publications are available at cost via the Government Printing Office (GPO). Electronic versions of publications may be downloaded, printed, and distributed.

    Publication Notes

    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
    • To view this article, download the latest version of Adobe Acrobat Reader.