## Study number:

## Data set ID:

## Data Access:

## Date range:

## Original investigator:

## Data contact:

## Abstract:

## Methods:

Field micro-cassette tape recorders

Study Site and Experimental Design Description A creosotebush shrub study site and a black grama grassland study site have been established at each of the Sevilleta, Jornada and Mapimi research locations. Each study site is 1 km by 0.5 km in area. Three rodent trapping webs and four replicate experimental blocks of plots are randomly located at each study site to measure vegetation responses to the exclusion of small mammals (see Figures 1 & 2 for diagrams of the two Jornada sites). The blocks of study plots are all oriented on a site in a X/Y coordinate system, with the access road to each site forming the X axis. The compass orientation at the Jornada grassland site is to the north, and Jornada creosotebush site is oriented to the south. Treatments within each block include one unfenced control plot (Treatment: C; control), one plot fenced with hardware cloth and poultry wire to exclude rodents and rabbits (Treatment: R; rodent), and one plot fenced only with poultry wire to exclude rabbits (Treatment: L; lagomorph), and one plot fenced with barbed wire to exclude cattle (Treatment B; bovine). Note that there are cattle exclosure plots only at the Jornada grassland site where cattle are present, for a total of 4 measurement plots at each of the grassland site blocks. There are only 3 measurement plots at each of the creosotebush site blocks. The treatments were randomly assigned to each of the four possible plots in each block independently, and their arrangements differ from block to block. Each of the plots in a replicate block are separated by 20 meters (see Figure 3). Each experimental measurement plot measures 36 meters by 36 meters (see Figure 4). A grid of 36 sampling points are positioned at 5.8-meter intervals on a systematically located 6 by 6 point grid within each plot. A permanent one-meter by one-meter vegetation measurement quadrat is located at each of the 36 points. The 36 quadrats are numbered 1-36, starting with number 1 in the top left corner of each plot, and running left to right, then down one row, and then right to left, and so on (see Figure 4). A 2-foot rebar marks the lower right corner of each quadrat, and an aluminum tag on the rebar gives the quad number. 3-inch nails were originally placed in the top left corner of each quadrat. These may be difficult to see. A 3-meter wide buffer area is situated between the grid of 36 points and the perimeter of each plot. Working on the Study Plots Always avoid walking on the quadrats, and do not walk across plots or anywhere within a block unless absolutely necessary. We are attempting to measure the effects of rodents and rabbits on plants and soils, not the effects of humans. When working on a plot, always walk on a line just below the rebar and quadrats, or on a line to the right of the rebar and quadrats (see dotted lines in Figure 4). Please try to walk gently and flat-footed on the study plots to minimize soil disturbance. When placing the vegetation measurement frame on a quadrat, be careful not to disturb the soil with the frame legs or your feet. When leaning over the measurement frame, be careful not to put your foot on the quadrat. We must measure all human caused disturbances to the soil surface of each quadrat. Vegetation Quadrat Measurements The foliage canopy area and maximum height of each plant species is measured from each quadrat. Several other variables are also measured from each quadrat, including soil surface disturbance, soil surface leaf litter cover, soil surface cryptogam crust cover, termite mud casing, and number of rabbit feces. All cover values are measured from the vegetation measurement frame, which is 1 meter by 1 meter, and partitioned into a grid of 100, 10 cm by 10 cm squares. Cover is measured by counting the number of 10cm squares that are occupied by the foliage canopy of a particular plant species, or by the soil disturbance, leaf litter etc. Portions of the 10 cm squares are also measured, down to 0.1 of a square. Detailed descriptions of measurement techniques are given below for each of the different variables measured. Placement of the vegetation quadrat measurement frame Walk from quadrat to quadrat along the lines mentioned above and marked in Figure 4. When you reach a quadrat, place one leg of the frame immediately next to and touching the 2-foot rebar, over the quadrat. Place the leg for the opposite corner of the frame (from bottom to top of a diamond shape) just inside of the 3-inch nail located at a 315 degree angle from the rebar on the plot X/Y, and compass coordinate system. The frame should be positioned so that the sides are parallel to the sides of the plot and directly over the quadrat, and in line with the rows of rebar (see Figure 4). You may not be able to see the nail, if not, line the sides of the frame with the rows of rebar the best you can. Recording Data You will record the quadrat data into your tape recorder. Each time you start recording data from a new plot (even if you are just helping someone else finish a plot), always start your recording by stating: "These are vegetation quadrat measurements for the Jornada small mammal exclosure study." Then state the date (month, day, year), the site (G or C), the block (1,2, 3, or 4), the plot (1, 2, 3, or 4), and the treatment (C, R, or L). If you are helping someone else on a plot, state so, and record who the other person is. Go to the first quadrat you will be taking measurements from, and record the quadrat number (1-36) before you start recording data, by stating "starting quadrat (n)". Note that (n) means whatever the appropriate number or letter is. When you are finished recording data for that quadrat, state "finished with quadrat (n)." Then go on to the next quadrat, and so on. When you have finished collecting data from the plot, state "finished with quadrat measurements on plot (n), of block (n), at site (n), on (date)." Additional Observations, Corrections, and Comments If you have already recorded data for a variable, e.g., rabbit feces, but while looking over the quadrat later, see some more, you may either make a correction to the previously recorded values, or make another observation (e.g., "correction, rabbit feces count (n)", or "rabbit feces count (n)." At any time, if you realize that you recorded incorrect data, just state "correction, ....." Always start corrections with the statement "correction". Do not try to run-back the tape and re-record over mistakes, just state "correction", and mention the problem. For comments, state "comment" and then record whatever you want to say about something. Comments are useful if you are uncertain about something, or see something unusual. Try to minimize use of comments though. Checking Your Tape Recordings Be sure to frequently play-back a small portion of your tape to verify that the tape recorder is working properly. Stop and play-back at least at the end of each line of 6 quadrats. Checking your tape after every other quadrat is even better. Labeling Your Tapes Be sure to label your tape, both on the cardboard case insert, and directly on the tape. Use the following format to label your tape: e.g., SMESVQF96-DL2 Where: SMES = small mammal exclosure study VQ = vegetation quadrat data F96 = fall 1996, or S96 for spring 1996 DL2 = initials for your name, in this case Dave Lightfoot, and the number of the ape, in this case, my second tape. Procedures for Vegetation Quadrat Measurements Below is a listing of procedures and values and ranges of values that you should record for each of the variables measured on the vegetation quadrats. IMPORTANT NOTE!!! Be sure to record an entry for all six of the following variables, even if the measurement or count is zero. So, for example, if there are no rabbit feces, record "rabbit feces count zero" or if there is no termite casing, record "termite casing zero" etc. Get into a routine of examining each quadrat for each of the 6 variables. For example, start with plant cover, starting with the dominant plant species, then look for leaf litter, then look for cryptogams, then look for soil disturbance, then look for rabbit feces, then look for termite casing. And be sure to record a value for each of the 6 variables for each quadrat. Leaf Litter Cover State "leaf litter cover(n)" for the cover of leaf litter on the soil surface of the quadrat in terms of the 10 cm squares. For cover values less than 5, use increments of 1.0. For cover values greater than 5, use increments of 5.0. Leaf litter includes all detached dead plant material on the soil surface, including woody branches. Only measure leaf litter cover that is in the open, do not attempt to measure within clumps of grass, etc. Some leaf litter cover has distinctive margins and is easy to define and measure. However, much leaf litter consists of many diffuse small patches that are separated by bare soil, and distributed throughout the quadrat. For such diffuse cover, determine the actual cover in one typical 10 by 10 cm square (e.g., 0.3), then count the number of squares with diffuse cover (e.g., 5), and multiply the number of squares by the actual cover for a typical square (e.g., 0.3 X 5 = 1.5, then round to 1.0 or 2.0, or if the value had been greater than 5, round to the nearest increment of 5.0 ) for the total litter cover. All litter cover is pooled into one observation, and no height is measured.

## Quality assurance:

SAS programs will be used to analyze data

## Additional information:

A creosotebush shrub study site and a black grama grassland study site have been established at each of the Sevilleta, Jornada and Mapimi research locations. Each study site is 1 km by 0.5 km in area. Three rodent trapping webs and four replicate experimental blocks of plots are randomly located at each study site to measure vegetation responses to the exclusion of small mammals. The blocks of study plots are all oriented on a site in a X/Y coordinate system, with the access road to each site forming the X axis. The compass orientation at the Jornada grassland site is to the north, and Jornada creosotebush site is oriented to the south. Treatments within each block include one unfenced control plot (Treatment: C; control), one plot fenced with hardware cloth and poultry wire to exclude rodents and rabbits (Treatment: R; rodent), and one plot fenced only with poultry wire to exclude rabbits (Treatment: L; lagomorph), and one plot fenced with barbed wire to exclude cattle (Treatment B; bovine). Note that there are cattle exclosure plots only at the Jornada grassland site where cattle are present, for a total of 4 measurement plots at each of the grassland site blocks. There are only 3 measurement plots at each of the creosotebush site blocks. The treatments were randomly assigned to each of the four possible plots in each block independently, and their arrangements differ from block to block. Each of the plots in a replicate block are separated by 20 meters. Each experimental measurement plot measures 36 meters by 36 meters (see Figure 4). A grid of 36 sampling points are positioned at 5.8-meter intervals on a systematically located 6 by 6 point grid within each plot. A permanent one-meter by one-meter vegetation measurement quadrat is located at each of the 36 points. The 36 quadrats are numbered 1-36, starting with number 1 in the top left corner of each plot, and running left to right, then down one row, and then right to left, and so on. A 2-foot rebar marks the lower right corner of each quadrat, and an aluminum tag on the rebar gives the quad number. 3-inch nails were originally placed in the top left corner of each quadrat. These may be difficult to see. A 3-meter wide buffer area is situated between the grid of 36 points and the perimeter of each plot. Rodent trapping webs are being used to determine the composition of rodent species at each study site, and to estimate densities of each species over time. The use of webs and distance measures to estimate rodent densities is statistically more robust than grid plot sampling and mark-release indices. Each rodent trapping web consists of a series of 12 equally spaced lines radiating from a central point. Each line consists of 12 trap stations. The first trap station is located 5 meters from the center, the next three at 5 meter intervals, and the remaining 8 at ten meter intervals. Each trap line is 100 meters long, and each web is 200 meters in diameter.

## Maintenance:

Twice each year through 1995: April and October Once every 5 years after 1995: October