Design, treatments, and soil measurements
This study was conducted on the Jornada Experimental Range (JER)
from 1933-2011 and is described in detail in Gibbens et al. 1983.
The study area is located on pasture exclosures in the basin where
typic haplargids of the onite series and typic torripsamments of
the pintura series dominate. Vegetation is dominated by large
honey mesquite dunes (Prosopis glandulosa) and black grama grass
(Bouteloua eriopoda). The Pasture 8B exclosure was established on
an area where mesquite dunes were large and well established. Many
seeding and transplanting trials were conducted from 1934-36 in
unsuccessful attempts to establish forage grasses and browse
species. In 1933, about half of the Site B exclosure was covered
with mesquite dunes. Grasses dominated the non-dune portion of the
exclosure but mesquite plants were present. To facilitate
vegetation type mapping, a 201.1 X 201.1 m (10 X 10 chain) grid
was laid out on the site Pasture 8B exclosure. Intersections of
grid lines (81 points) were marked by steel fence posts. In
February, 1935, the soil level at each grid point post was marked
by filing a notch in the post 15.2 cm above the upper face of a
30.5 cm wooden ruler laid on the soil surface in a north-south
direction on the east side of the post. In I931, a 201.1 X 100.6 m
(10 X 5 chain) grid was laid out on the Natural Revegetation
(NatReveg) exclosure. Grid line intersections (153 points) were
marked with a 1.2-m length of 3.2-cm pipe. Soil levels were
marked, as described above, on the pipes in May, 1933. A
re-measurement of soil levels at the grid markers was made in
February, 1935. A transect was established across the NatReveg
exclosure in 1935. Stakes 66 cm long cut from steel fence posts
were driven 43 cm into the ground at 15.2-m intervals. The
transects, which followed a north-south grid line 604 m from the
west side of the exclosure, extended 61 m beyond the exclosure
fence on the north and south sides. Soil levels were marked, on
the 104 transect stakes in April, 1935.
For re-measuring, a metal detector was used to locate completely
buried stakes. These were carefully excavated, preserving a
reference to the current soil surface level. Frequency of
re-measurement occurred every 5 years except for after 2000
(1933/35, 1950, 1955, 1980, 1985, 1990, 1995, 2000, 2011).
References
Gibbens, R.P., J.M. Tromble, J.T. Hennessy, and M. Cardenas, 1983.
"Soil movement in mesquite dunelands and former grasslands of
southern New Mexico from 1933 to 1980." Journal of Range
Management 36:145-148
