Nevada Desert Face Facility Soil Water Content (%Vol)

Method: 16 Dynamax TDR probes were installed in each ring in two microsite
locations: a pair of 0.2- and 0.5-cm probes was installed under the canopy
of four randomly selected Larrea plants in each plot, with another pair
installed nearby in the interspace between perennial plants. Initially, 44%
of the 0.5-m probes were not fully inserted into the soil because rocks in
the soil impeded installation. For these probes, we corrected the soil water
measurement based on the proportion of the probe length in air because the
dielectric constant of air (1) is much less than that of water (80)
(Topp 1993). By December 1999, all these TDR probes had been relocated in
their respective microsite location so that they were fully inserted into
the soil. [see Nowak et.al. (2004) Elevated atmospheric CO2 does
not conserve soil water in the Mojave Desert. Ecology 85:93-99.]