The soil heat flux (G) is an important component of the surface energy balance equation, especially in arid lands. Estimating G for a flat homogeneously vegetated surface has become a fairly routine matter. However, for a desert landscape with a heterogeneous surface and complex terrain, it becomes increasingly complicated to estimate an appropriate aggregated value for G. At the Jornada Experimental Range near Las Cruces, New Mexico, a single 20 m2 by 2 m tall Honey Mesquite (Prosopis glandulosa var. glandulosa) dune was instrumented with an array of 20 soil heat flux thermopiles and thermocouples buried below the surface in a grid pattern with a nominal spacing of 1 m between sensors. This allowed for a spatial distribution of multiple sensors representing open bare soil, partially shaded, and fully shaded with a 1 m2 resolution. Preliminary results show G to be spatially and temporally distributed as a function of sun angle, vegetative cover, and microtopography. Depending on the time day, variations among sensors can range from -40 to 200 Wm-2 . In a desert ecosystem this has important implications for estimating latent and sensible heat fluxes using an energy balance approach, namely determining what soil heat flux value appropriately represents a Mesquite dune ecosystem and for which spatial and temporal scales. These issues become particularly critical when attempting to determine G for much larger areas for purposes associated with remote sensing approaches for estimating regional surface energy fluxes. A series of 3-d surface maps of G representing different temporal periods will be presented as well as a discussion relating G to sun angle and vegetative cover.