The influence of Larrea divaricata on soil moisture and on water status and growth of Stipa tenuis in southern Argentina

We studied the effect of a dominant shrub (Larrea divaricata) on soil moisture, and how this affected water potential and growth of a dominant grass (Stipa tenuis) in a shrubland located in southern Argentina. Soil moisture in the upper 10 cm of the soil was lower (p<0•05) or similar (p<0•05) under the shrub canopy than in the open intercanopy spaces. Concordantly, predawn leaf water potential and growth of Stipa tenuis were higher or similar in intercanopy locations than in canopy locations. The physical presence of L. divaricata canopy frequently reduced soil moisture availability for understory plant growth, in part because of canopy interception of precipitation