Connectivity Modifier (Conmod) Pilot methods
The data table in this data package contains the mass and loss on
ignition percentages of bedload samples collected at plots in
2008-2010. Observations impacting the quality of these measurements
are recorded in the history file. A schematic of how the line-point
intercept transects were arranged with respect to the study plots is
also included in the data package. Both of these documents are
listed in the "Additional documents" section below)
Basic Study Set Up and Location
There are 3 sites for the Conmod Pilot study: Gravelly Ridges,
Aeolian, and Dona Ana (referred to as G, A, and D, respectively).
Within each site, there are 8 plots. The plots are 8 x 8 meters and
have an 8 x 8 meter buffer zone on both sides of the plot (upwind
and downwind). At each site, 4 of the 8 plots are treatment plots
where connectivity modules (conmods) have been installed to decrease
the gap size between perennial vegetation. The other 4 plots are
untreated controls. Buffer zones do not have conmods installed.
Belowground catchment containers, or bedload samplers, were
installed in the upslope (2-3) and downslope (2-3) buffer zones of
each plot in 2008 for a total of 4-6 samplers per plot. Bedload
sampler bottles were collected or cleaned out once a month. Before
arriving to field, technicians checked weather records to get an
estimate of rainfall over last month to help determine whether there
was a flow event. Upon arriving to the field, bottles were checked
and if there was bedload (sediment or particulates), a substantial
amount of water, or dried water lines in the bottles they were
collected. If there was only litter and/or very little, loose, wind
blown soil in bottle, then bottles were emptied and replaced. Only
material from bedload (material moved from overland flow of water)
was collected; water and material in a bottle solely from a rain or
wind event was not collected.
NOTE - users will want to know which samplers are upslope
and which are downslope from the plots (out of samplers
A-F)
Samples returned to the lab were dried in the bottle in a drying
oven until completely dry. Dry bottles with the bedload material
were weighed before and after the bedload material was removed to
estimate the mass of the material. Bedload material from the bottles
was then transferred to ceramic crucibles, oven dried at 105 degrees
Celsius for 2 hours, and combusted in a muffle furnace at 400
degrees Celsius for 8 hours. Loss on ignition percentage was
calculated as (1 - combusted mass / initial mass) * 100.
Measurements for this data package were made annually during
2008-2010, and only for overland flow events.
Treatment plots by site
Aeolian site: 1,3,6,7 (Control plots are 2,4,5,8)
Dona Ana site: 1,3,6,8 (Control plots are 2,4,5,7)
Gravelly Ridges site: 2,4,6,8 (Control plots are 1,3,5,7)
Additional documents
A schematic of the location of the bedload samplers (called
"sediment collectors") are found in
"Connectivity_Study_Design_Schematic.pdf"
Historical and contextual notes about data collection (and the
"comments" column) are found in the file
"Connectivity-pilot_his.txt"
References
Herrick, J. E., J. W. Van Zee, K. M. Havstad, L. M. Burkett, and W.
G. Whitford. "Monitoring manual for grassland, shrubland and
savanna ecosystems, Volume I." US Department of
Agriculture-Agriculture Research Service, Jornada Experimental
Range, Las Cruces, New Mexico (2005).
