The U.S. Fish and Wildlife's plan to apply a prescribed burn to a large portion of Mckenzie Flats was deemed an opportunity to study the effects of fire on vegetation at the boundary between shrubland and grassland. This study actually was undertaken on an area that had prescribed fire applied to 8 of 16 (300 m x 300 m) plots 10 years before in 1993. This previous study had also examined the effects of fencing to exclude the indigenous prong-horn antelope. In the 2003 study the prescribed fire was applied to the northeastern half of the 16 plots while the southwestern plots were intentionally protected. Sampling prior to the prescribed burn included quantification of cover of grass species in quadrats within all of the 16 plots. Measurements were made using "niner" quadrat frames that are 30 cm x 30 cm frames that are divided into 9 1-decimeter squares. Counts of grass species were made just prior to the June 2003 burn. Following the prescribed burn, quadrats were remeasured in the fall of 2003 to quantify mortality of grass species. These measurements were taken through the fall of 2012
To study the effects of fire on the vegetation at the boundary between shrubland and grassland.
Within each 300 m x 300 m plot, 3 m x 4 m quadrats were marked off with rebar for use in a previous burn experiment. Each of these quadrats also had a piece of rebar on the southern edge of the quadrat with a numbered tag. Six of these quadrats were randomly selected in each plot. Measurements were made using a niner quadrat frame. These frames are PVC squares that are 30 cm x 30 cm and are divided off into 10 cm x 10 cm squares with string. This gives nine 1-decimeter squares within the "niner". The niner was placed over a corner rebar and aligned with the edge of the larger 3 m x 4 m quadrat. Counts were then made of the number of decimeters in which each species of grass was rooted. Values can be 0 to 9. The designation for the 4 niners in each quadrat was A through D starting with A in the SW corner, moving clockwise to D in the SE corner.
Note: For the fall collection in 2003 it was virtually impossible to identify the species of grass that had regrown following the fire. It was decided to just give a count of decimeters with live grass rooted in them and identify them as "GRASS". With the fall moisture of 2003 there was a flush of annuals and it was decided to enumerate these with counts of any "forbs" rooted in decimeters of each quadrat. This methodology was not repeated in subsequent years.
Also, Quad 3084 was not recorded in the 2003 season 2 and any years following 2005. For Quad 3141, data were not measured for years following 2006. This was done to balance the dataset; each "pre" plot has six quadrats rather than some having seven.
Data were collected from 16 (300 m x 300 m) plots designated as the "Burn Antelope Exclosure" plots. These plots are located on the southern end of Mckenzie Flats. The plots are laid out in a 4 by 4 square with 300 m buffer between each plot. The plots are enclosed within a 440 ha box.
The bounding coordinates of this large box are:
NW corner 34.3138 106.6926
NE corner 34.3202 106.6711
SE corner 34.3024 106.6634
SW corner 34.2960 106.2960
This large expanse has a variable mix of grass species. The 2 dominant species are black grama (Bouteloua eriopoda) and blue grama (Bouteloua gracilis). There are also sizeable patches of mule grass (Scleropogon brevifolius). A mixture of the dropseed species are present as well. These include Sporobolus cryptandrus, Sporobolus contractus, Sporobolus flexuosus and Sporobolus airoides. Galleta grass (Pleuraphis jamesii) and a couple of Muhlenbergia species are also present. Into this grass matrix are mixed several shrubs and subshrubs. The most noticeable shrub is creosote bush (Larrea tridentata). Other common non-grasses include Yucca glauca, Ephedra torreyana and Gutierrezia sarothrae.
2003 through 2008 data files were merged into one file. Then, they were checked for obvious errors. 20 January 2009. TLK
checked and corrected 2009 data for obvious errors, appended data to Navicat table. 12 January 2010 tlk
Data were recorded on paper datasheets. Then this data were entered into an excel worksheet and assessed for errors. Data are stored in Navicat table niners_grass in directory burnx. In 2009, started distinguishing between field comments and QAQC comments. An '*' designates a QAQC comment. SAS program is used to check for duplicates and that all data points have been recorded and entered.
Spring 2003 data were measurements done before the 2003 prescribed fire. Data collection is ongoing.
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