Basic Experimental Design
The experiment was designed to test the effects of increasing wind
erosion on soil and vegetation properties at the Jornada. In order
to increase wind erosion rates, vegetation was removed to increase
bare surface area and stimulate erosion (the less vegetation present
the greater the wind erosion). The basic experimental design
includes three treatment blocks. Each block has four treatment plots
with different levels of vegetation removed (25-100%) and a control
treatment. Treatment plots are 25x50 meters with 25 meter buffers
between. The vegetation removal includes grasses and small shrubs
(like Gutierrezia sarothrae and Zinnia grandiflora), but not
mesquite, yucca, or any of the larger shrubs. Also, adjacent
downwind plots are included in the design. These plots are strictly
for monitoring of soil and vegetation properties, so no maintenance
is required on these areas.
Each treatment area (upwind) and adjacent downwind area has 6 BSNE
stands, each with 6 or 4 dust collectors per vertical stand. There
are two exceptions: Block 1, Treatment C has 3 downwind stands;
Block 2, Treatment 3 has 4 downwind BSNE stands. On the Treatment 4
Upwind plots (the area with the most vegetation removal) these
stands are 3m tall with 6 traps at heights 15, 30, 60, 90, 160, 250
cm respectively. All the other stands, including Treatment 4
Downwind, the dust collectors are 1 meter tall. The heights on these
are 15, 30, 60, 120 cm. Heights are based on distance from ground to
bottom of BSNE opening when collector is pointing 250° from true
North (the prevailing wind direction).
A schematic of the plots is provided in
"NEAT_BSNE_map.tif". Please note that
the number, arrangement, and/or height of BSNE stands and collectors
in NEAT plots has changed somewhat over time. Most of these changes
are evident in the data or metadata, and complete historical details
are available upon request from the JRN LTER data manager.
BSNE sampling and maintenance
Except for 2008 when it was an annual collection, BSNEs are
collected twice a year, typically February (before windy season) and
June (after windy season). As part of the biannual collection, the
trap heights need to be measured and adjusted accordingly, along
with any other maintenance that needs to be done (such as rewiring
the traps, rebalancing the 3 meter stands, veg clipping, etc.).
Vegetation is clipped as needed to allow BSNEs to freely rotate
360º. The dust from each trap gets placed in a 6x4 inch, 4-mil
Ziploc-style bag and appropriately labeled and dated.
The air dry weight in grams of the dust sample in each collector is
calculated from the mass of the sample and the bag minus the average
mass of all bags used during the collection ( (Bag + Sample) -
Avg_Bag_Wt ).
The general protocol and guidelines for BSNE data collection are
described in detail in the attached "BSNE-protocol.pdf"
document. This document is not specific to the NEAT study.
