Soil movement across black grama-mesquite ecotones beginning in 1933

In 1933 and 1935, two transects were established in the Natural Revegetation Exclosure and
Pasture 8b, respectively, to measure long-term soil movement in areas undergoing mesquite
invasion. These two transects, established in a Prosopis-Bouteloua ecotone, were to: "measure
any future changes in the extent or succession of three contiguous zones of vegetation,
Bouteloua eriopoda, Gutierrezia, and Prosopis glandulosa dunes. Thus, future chartings of this
transect should show whether, under the range management practiced, the succession is
progressing toward the black grama climax or whether it is retrogressing toward mesquite
sandhills." (E.L. Little, 1935, unpublished report) Soil movement at these transects was
measured by the distance between the soil surface and a notch in 50 cm t-posts located every
15.2 m (50 ft). The 1731-m Natural Revegetation Exclosure tranect runs north-south through the
center of the exclosure and extends 61 m (200ft) beyond the boundary fence on either end. It is
located in primarily deep, loamy sand soils. The 457-m Pasture 8b transect is oriented WSW-ENE,
and is located in shallower soils. These transects were measured in 1950 (8b only), 1955 (8b
only), every five years from 1980-2000, and most recently in 2011. Most steel posts were
remeasured at these intervals, but some were lost due to excavation or burial. These were for
the most part replaced, with a new baseline notch height initiated on the posts. Data fields
correspond to each year of collection, as well as measures of soil deposition or deflation
during the intervals. Spatial data include post locations and identifiers.