How do sediment transport rates impact vegetation growth and groundwater depth in a desert dune field?

Spatial variability in sediment transport can drive changes in dune morphology and vegetation cover across desert dunefields. Due to the complex interaction of vegetation with both water table dynamics and the soil-salt balance a discontinuous ecosystem response may exist. Field observations show that a transition between two stable states for the relation between vegetation, groundwater depth, and soil salinity partitioning exist at White Sands National Monument, New Mexico. Across the  gypsum dune field there is an abrupt transition between a shallow, saline groundwater table below actively-migrating, unvegetated barchan dunes, to stable, vegetated parabolic forms atop a deep, fresh groundwater table.  The transition between these two stable states is governed by an across dunefield decrease in sediment flux resulting from the creation and subsequent relaxation of a turbulent boundary layer.

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tl;dr  Decreased sediment flux allows for increased vegetation colonization, drawing down and freshening the water table, concentrating salts in the soil surface. The transition is RAPID!

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