ΔNDVI morning-midday and ΔNDVI winter-summer of the Bellavista plantation in 2007.

<p><b>Winter 2007:</b> (A) Landsat NDVI, (B) MODIS-Terra NDVI (morning), (C) MODIS-Aqua NDVI (midday), (D) ΔNDVI_mo-mi  =  B–C; <b>Summer 2006–07</b>: (E) Landsat NDVI, (F) MODIS-Terra NDVI (morning), (G) MODIS-Aqua NDVI (midday), and (H) ΔNDVI_mo-mi  =  F–G. Graphs I, J and K display the <b>ΔNDVI_W-S 2007</b>, where (I) Landsat ΔNDVI_W-S  =  A–E, (J) MODIS-Terra ΔNDVI_W-S  =  B–F, and (K) the MODIS-Terra ΔNDVI_W-S  =  C–G.</p

Pulvinar structures of Prosopis tamarugo leaves.

<p>(A) Tamarugo trees, (B) leaf angle randomly distributed during the morning when the solar radiation is low, (C) leaf angle in erectophyle position to avoid facing high solar irradiation at midday, (D) transversal section of a closed pulvinus (empty of water) during the morning, (E) transversal section of an open pulvinus (filled with water), which allows leaves to stand up and reach the erectophyle position, and (F) detail of the base of a Tamrugo pinna showing the three levels of pulvinar structures (at the base of the bipinna, of each pinna and each foliole).</p

Plantation stands close to monitoring wells in the Pampa del Tamarugal basin.

<p>(*)Groundwater depth and depletion estimated using inverse distance weighted interpolation of 3 neighbouring wells.</p><p>Plantation stands close to monitoring wells in the Pampa del Tamarugal basin.</p

Water stress stages of Tamarugo desert trees and NDVI based variables to assess their effects using satellite remote sensing.

<p>Water stress stages of Tamarugo desert trees and NDVI based variables to assess their effects using satellite remote sensing.</p

Conceptual diagram of the effect of leaf pulvinar movement on the NDVI signal.

<p>(A) NDVI difference between morning and midday (ΔNDVI_mo-mi) occuring as solar irradiation changes during the day, and (B) NDVI difference between winter and summer (ΔNDVI_W-S) occuring as solar irradiation varies between seasons. The time at which the Landsat (5–7), MODIS-Terra, and MODIS-Aqua satellites acquire data is displayed to illustrate the impact of pulvinar movements on the NDVI retrieved from these platforms.</p

Time series of groundwater depth, Landsat NDVI_W, and Landsat ΔNDVI_W-S for six Tamarugo plantation stands.

<p>Blue arrows indicate precipitation events.</p

Landsat NDVI image showing the location of the Tamarugo stands (Winter 2007).

<p>Landsat NDVI image showing the location of the Tamarugo stands (Winter 2007).</p

Landsat ΔNDVI_W-S of all plantation stands in 1997, 2007, and 2011 (after a precipitation event).

<p>Landsat ΔNDVI_W-S of all plantation stands in 1997, 2007, and 2011 (after a precipitation event).</p

Time series of solar irradiation and NDVI for the B1 site (low groundwater depletion).

<p>(A) Solar irradiation, (B) MODIS 16 days composite NDVI, and (C) Landsat NDVI of the B1 site. Arrows indicate the peak of Tamarugo's vegetative period. S = summer, W = winter.</p