This study measured the population dynamics of coyotes in the grasslands and creosote shrublands of McKenzie Flats, Sevilleta National Wildlife Refuge. The study was begun in January, 1992, and continued quarterly each year. Coyotes were sampled via scat counts along the roads of McKenzie Flats during winter, spring, summer, and fall of each year. The entire road transect was 21.5 miles in length. Scat counts over a week period (number of scats/mile/day) in each season along the roads were used to calculate the densities of coyotes (number of coyotes per square kilometer). Results from 1992 to 2002 indicated that autumn was the peak density period of the year, with generally steady declines through the year until the following autumn. Coyote populations appeared to fluctuate seasonally, but remained relatively stable at 0.27 +/- 0.03 (SE) coyotes per km2 during summer periods (this likely represents the "breeding pair" density, during which coyote pairs have set up territories and are raising young, but the pups have not as yet joined the parents in foraging activities).
The purpose of the study was to assess the dynamics of coyote populations in the grasslands and creosote shrublands of the Sevilleta NWR. Coyotes are important predators and omnivores in these habitats, feeding on a wide variety of vertebrates, arthropods, and plants. Populations of prey species may be controlled to some extent by coyote predation, in which case coyotes may have significant influences on the biodiversity and species composition of the desert grassland ecosystem.
The scats were sampled along 21.5 miles of roadway that was broken up into four "legs" of varying lengths.
Leg A: Black Butte southward to Five Points (5.7 miles).
Leg B: Five Points eastward to the turnoff before Palo Duro Canyon (4.1 miles).
Leg C: Palo Duro turnoff northward to the old McKenzie Headquarters site (6.1 miles).
Leg D: McKenzie Headquarters site northwestward to Black Butte (5.6 miles).
Each scat was the unit of sample.
Frequency of Sampling:
Sampled one week per season, four seasons per year.
Variable, depending on scat abundance.
Knowlton, Frederick F. 1984. Feasibility of Assessing Coyote Abundance on Small Areas. Unpublished Report, 14 pp.
The number of scats deposited by coyotes per mile of roadway per day in a typical western basin-and-range landscape has been shown to be correlated with the absolute density of coyotes. Therefore, the objective was to measure the deposition rate of coyote scats on the roads of McKenzie Flats.
The process involved two samplings along the roads. The first sampling involved the "clearing" of scats from the 21.5 mile survey route, so as to initialize the roadway with zero scats. On the assigned day, the technician would drive an ATV slowly (less than 5 miles per hour) along the route. When a coyote scat was observed, the technician would stop and pick up the scat, placing it into a zip-lock plastic bag that was labeled with the date and the "leg" letter. Each "leg" was bagged separately. The odometer reading of the scat location was recorded on the data sheet. If more than one scat was observed at the same place, the number of scats was recorded as well. For health and safety, the technician wore gloves during this process, or used tongs or a small trowell to pick up the scats and place them into the bag. When using the ATV, the technician wore a safety helmet.
During the early sampling periods (1992 to 1993), prior to the acquisition of the ATV in 1994, scats were collected by two technicians in a pick-up truck. One technician would drive, and the other would ride on the engine hood above the bumper, and scan the road as the truck was driven slowly along the road. When a scat was observed, the driver would stop the truck while the rider would collect the scat. The same data were recorded as described above.
One week following the "road clearing" survey, a second collection took place. The scats were sampled in the same fashion as before, but each scat was placed individually in a labelled small zip-lock plastic bag. Again, odometer readings were taken at the point of collection. Multiple scats from the same location were placed in separate plastic bags.
The scats were then returned to the field station, and placed in freezers for preservation pending analysis of dietary items.
Density values were computed as numbers of individuals per square kilometer. According to F. Knowlton (see reference above), the relationship between absolute densities of coyotes (x-value, independent variable) and the number of scats per night per mile x 100 (y-value, dependent variable) is:
Y = 2.66 + 11.42X, r2 = 0.97, n = 8
Transforming this equation for computing densities of coyotes from numbers of scats for each "leg" of the survey, and converting these values to numbers of coyotes per square kilometer, the coyote density equations for each survey "leg" are as follows:
D = Density of coyotes/km2, N = Total Number of Scats Collected/Leg
after a 7-day period.
Leg A (5.7 miles): D = [0.2195(N) - 0.2329]/2.59
Leg B (4.1 miles): D = [0.3052(N) - 0.2329]/2.59
Leg C (6.1 miles): D = [0.2052(N) - 0.2329]/2.59
Leg D (5.6 miles): D = [0.2235(N) - 0.2329]/2.59
The samples (scats) were collected in winter, spring, summer, and fall, of each year. Scats were collected from the road once at the beginning of a collection period, and once at the end (usually, one week later) during each of these four seasons per year. Months of collection varied in some years, but generally the sampling was conducted in January, April, July, and October. The study began in January, 1992, and is continuing.
Keystone species have large impacts on community and ecosystem properties, and create important ecological interactions with other species. Prairie dogs (Cynomys spp.) and banner-tailed kangaroo rats (Dipodomys spectabilis) are considered keystone species of grassland ecosystems, and create a mosaic of unique habitats on the landscape. These habitats are known to attract a number of animal species, but little is known about how they affect arthropod communities. Our research evaluated the keystone roles of prairie dogs and kangaroo rats on arthropods at the Sevilleta National Wildlife Refuge in central New Mexico, USA. We evaluated the impacts of these rodents on ground-dwelling arthropod and grasshopper communities in areas where prairie dogs and kangaroo rats co-occurred compared to areas where each rodent species occurred alone. Our results demonstrate that prairie dogs and kangaroo rats have keystone-level impacts on these arthropod communities. Their burrow systems provided important habitats for multiple trophic and taxonomic groups of arthropods, and increased overall arthropod abundance and species richness on the landscape. any arthropods also were attracted to the aboveground habitats around the mounds and across the landscapes where the rodents occurred. Detritivores, predators, ants, grasshoppers, and rare rodent burrow inhabitants showed the strongest responses to prairie dog and kangaroo rat activity. The impacts of prairie dogs and kangaroo rats were unique, and the habitats they created supported different assemblages of arthropods. Where both rodent species occurred together on the landscape, there was greater habitat heterogeneity and increased arthropod diversity.
Landscape-scale plots: We compared grasshoppers on plots occupied by:1) both species (Pdog+Krat plot);2) only kangaroo rats (Krat plot); and 3) both species, but where prairie dogs inhabited one half of the plot and kangaroo rats inhabited the other half (Transition plot).Sampling Design
The landscape-scale plots were 180 m x 180 m. Grasshoppers were visually sampled along strip transect lines established along each gridline of the landscape-scale plots, using a 5 x 5 grid array. Strip transects on the landscape-scale plots measured 1 m x 30 m.Field methods
Grasshoppers were sampled by walking slowly along each transect,tapping the soil and vegetation with a 1 m long, 1.27 cm diameter white PVC pipe. Grasshoppers flushed from the ground were counted and identified to species, and the substrate (i.e., plant species, bare soil) they were observed on was recorded. This is the standard method used at both the SEV and Jornada LTER sites, and is similar to that developed by Paftd (1982). Grasshoppers were sampled during spring (April) and fall (September), from fall 1999 through spring 2002 at the SNWR.Laboratory Procedures
Grasshopper voucher specimens from this study were deposited in the collection of the Arthropod Division, Museum of Southwestern Biology at the University of New Mexico.
01/09/2009 (YX): the metadata was entered from metadata supplied by Ana Davidson 1/25/2008
(Yang Xia) - updated and modified metadata to correct format;checked data for missing data points and errors;- any empty cells were filled in with either -999 for missing data
Additional Personnel with Data Collection
Julie McIntyre was part of the field crew in collecting/processing samples.
Additional Study Area Information
Study Area Name: Pino Gate
Study Area Location: The study site was located near the base of the Los Pinos mountains and directly adjacent to the nothern fencline of the SNWR at Pino Gate.Elevation: 1600 m
Vegetation: Burrograss (Scleropogon brevifolius), sand dropseed (Sporobolus cryptandrus), and black grama (Bouteloua eriopoda) were the dominant vegetation.
Soils: Deep clayey loam soilsGeology: On an upper bajada slope, in a broad swale
Climate: Long-term mean annual precipitation is 243 mm, about 60% of which occurs during the summer. Long-term mean monthly temperatures for January and July are 1.5°C and 25.1°C, respectively.
Site history: Historically, prairie dogs were common throughout the area, but were exterminated by the early 1970’s (John Ford, United States Department of Agriculture Wildlife Services, personal communication). Gunnison’s prairie dogs began to re-colonize the study site from adjacent private land in 1998. During our study, the colony occurred within a 5 ha area, near the base of the Los Piños Mountains in an area with deep clayey loam soils. The site has been long inhabited by kangaroo rats, and represents typical northern Chihuahuan Desert grasslandNorth Coordinate:34.406954South Coordinate:34.406954East Coordinate:106.606269West Coordinate:106.606269
Grasshoppers are important animals in semi-arid environments, both as herbivores and as food resources for higher level consumer animals. Grasshoppers tend to be numerous and represented by many species in semi-arid environments, especially in desert grasslands. Grasshopper species range from environmental specialists, to environmental generalists. Grasshopper populations tend to change considerably from year to year, often in response to annual variation in rainfall and plant production. The purpose of this study was to monitor grasshopper species composition and abundance over a period of many years from black grama grassland, blue grama grassland, creosotebush shrubland, and pinyon/juniper woodland environments at the Sevilleta, in relation to seasonal and annual variation in precipitation and plant production. Data were collected for all individual species to provide information on community dynamics as well as population dynamics. The working research hypothesis for this study was that grasshopper populations in all environments will correlate positively to seasonal and annual variation in precipitation and plant production. Spring grasshopper populations will be especially high during El Nino years, and late summer populations especially high during La Nina years. This study was initiated in 1992, and is ongoing to the present time.
Physical Dimensions of Sampling Area: 50-meter by one-meter strip transects, between 6, alternating end-points of rodent trap lines on each of 5 rodent trapping webs at each of the 4 sites.
Plot size: Each trapping web is 200-meters diameter, each grasshopper count strip is 50-meters long, by one-meter wide.
Transect Length: 50-meters.
A sample unit consists of 50 by 1-meter strip transect; 6 strip transects per web, 5 webs per site.
Frequency of Sampling
Samples are collected twice each year, early summer and late summer.
Sample size consists of 50-meter by one-meter strip transects.
Visual counts of all grasshoppers on each strip transect. The observer slowly walks each transect, flushing grasshoppers ahead with a one-meter long - inch white PVC pipe. The observer records data on to a voice-activated micro-cassette recorder. Information recorded includes for each individual grasshopper: species, geneder, age class, and the substrate from which the grasshopper was flushed.
Study Area 1
Study Area Name: Goat Draw (Cerro Montosa)
Site Location Description: Cerro Montosa draw, at north base of Cerro Montosa, Sierra Los Pinos.
Soil: rocky loam.Slope/Aspect: variable steep slopes, all aspects. Vegetation Community: pinyon/juniper woodland, blue grama understory.Terrain/Physiography: rough, dissected erosional montane hills, slopes, and drainages.Geology/Lithology: variable, rhyolite. Hydrology - surface/groundwater: extensive steep arroyo drainages.Size: approximately 1 by 3 km.History (if known): grazed by cattle until 1973.Elevation: approximately 2,000 meters.Climate (general): semi-arid montane, summer rain.
Study Area 2
Study Area Name: Five Points Creosotebush.
Site Location Description: approximately 2km west of Five Points, McKenzie Flats. Soil: sandy loam.Slope/Aspect: slight north-facing slope.Vegetation Community: Chihuahuan Desert creosotebush/black grama grass.Terrain/Physiography: top of Palo Duro Canyon escarpment to south, gentle slope to north. Geology/Lithology: alluvial outwash, extensive caliche near surface.Hydrology - surface/groundwater: slight drainage to the north.Size: approximately 1 by 2 km.History (if known): intensively grazed by cattle until 1973. Elevation: approximately 1,600 meters.Climate (general): semi-arid, summer rain.
Study Area 3
Study Area Name: Five Points Grass.
Site Location Description: approximately 2km NW of Five Points, McKenzie Flats. Soil: sandy loam.Slope/Aspect: gentle rolling terrain.Vegetation Community: black grama grassland.Terrain/Physiography: gentle rolling terrain.Geology/Lithology: alluvial outwash, limestone and caliche.Hydrology - surface/groundwater: slight drainage to the west.Size: approximately 2 by 2 km.History (if known): intensivey grazed by cattle until 1973. Elevation: approximately 1,600 meters. Climate (general): semi-arid, summer rain.
Additional Information on the Data Collection Period
Data are collected in the early summer (April/May) and late summer (September/October).
SEVILLETA LTER CORE SITE GRASSHOPPERSGrasshopper Species ListUpdated: 01/19/00
CODE, FRM L-H, LATIN NAME
ACPI, G, U, Acantherus piperatusAGDE, GT, U, Ageneotettix deorumAMCOG, U, Amphitornus coloradusARCO, T, P, Arphia conspersaARPS, T, U, Arphia pseudonietanaAUEL, GT, U, Aulocara elliottiAUFE, GT, U, Aulocara femoratumBOAR, A, U, Bootettix argentatusBRMA, GT, U, Brachystola magnaCIPA, T, P, Cibolacris parvicepsCOCR, GT, U, Cordillacris crenulataCOOC, GT, U, Cordillacris occipitalisCOTE, T, U, Conozoa texanaDABI, GT, U, Dactylotum bicolorERSI, G, U, Eritettix simplexHATR, T, U, Hadtrotettix trifasciatusHERU, T, U, Heliaula rufaHEVI, A, U, Hesperotettix viridisHICA, T, U, Hippopedon capitoLAAZ, T, U, Lactista aztecaLEWH, T, U, Leprus wheeleriMEAR, A, U, Melanoplus aridusMEAZ, GT, U, Melanoplus arizonaeMEBO, A, U, Melanoplus bowditchiMEGL, GT, U, Melanoplus gladstoniMELA, GT, U, Melanoplus lakinusMEOC, GT, U, Melanoplus occidentalisMETE, G, U, Mermeria texanaOPOB, G, U, Opeia obscuraPAPA, G, U, Paropomala pallidaPHQU, GT, U, Phlibostroma quadrimaculatumPHRO, T, P, Phrynotettix robustusPSDE, GT, P, Psoloessa delicatulaPSTE, GT, P, Psoloessa texanaSCNI, A, U, Schistocerca nitensSYMO, G, U, Syrbula montezumaTRCA, T, U, Trimerotropis californicusTRFO, H, U, Tropidolophus formosusTRKI, T, U, Trachyrhachis kiowaTRPA, T, U, Trimerotropis pallidipennisTRPI, T, U, Trimerotropis pistrinariaXACO, T, P, Xanthippus corallipesXAMO, T, P, Xanthippus montanus
The line-intercept transects included in this data set have been discontinued. These transects were installed to evaluate temporal and spatial dynamics in vegetation transition zones (e.g.black grama grassland/creosote shrubland) at one centimeter resolution. Each study site originally contained four 400 m transects, representing total coverage of 1 sq km. The transects were placed along a roughly north/south azimuth. The northwestern and southwestern transects were 100 meters from the western edge of the 1 sq km study area and the northeastern and southeastern transects were 100 m from the eastern edge, providing 800 meters between the eastern and western transects. The northeastern and northwestern transects began to the north and, after an interval of 200 meters, the southeastern and northeastern transects began, terminating at the southern edge of the study area.
Ongoing line-intercept transect data for transect 1, which continues to be sampled at both Deep Well and Five Points, can be found in SEV004.
Measuring the Transects: A 100 m tape was attached to permanent pieces of rebar at each of the four segments of a 400 m transect. The tape was stretched as tightly as possible to get the straightest line. Windy days were avoided as this became impossible.
Crew members worked independently, each sampling a 100 m segment simultaneously. Microcassette recorders and standard microcassettes were used to record data. At each 100m segment, the following sequence was followed:
Each species or substrate encountered along a transect was recorded at the centimeter level. The distance at which a species or substrate first crossed the tape was recorded. Starting points only were recorded as the ending point of a species or substrate was the starting point of the next. It was also noted whether vegetation was fully alive, fully dead or a mix of both.
Changes to the data: This dataset (SEV200) includes all discontinued line-intercept transect data files. In particular, data is included from Bronco Well, Valle de la Jornada, Rio Salado and Sepultura Canyon, as well as transects 2-4 from Deep Well and Five Points. Transect 1, season 2 data from Deep Well and Five Points in 1994 is also included (1994 was the only year that three seasons od data were collected). Otherwise, SEV004 contains transect 1 data from Deep Well and Five Points.
The data in this file has not been rigorously QA/QCed. Old metadata and individual year data can be found in: /export/db/local/htdocs/data/archive/plant/transect/data_oldformat. This data will not be available online. See the Sevilleta data manager for data and metadata in this old format.
Principle investigator:1989-1998: Milne, Bruce; Gosz, JimData Manager:1989-1992: Taugher, Kimberly 1993: Maddux, Troy; Taugher, Kimberly 1994: Maddux, Troy; Taugher, Kimberly; Chavez, Melissa1995: Geer, Susan; Taugher, Kimberly1996-1998: Taugher, KimberlyField Crew1989: Banar, Alethea; Keller, David; Loftin, Sam; Maddux, Troy; Wolterstorff, Susan1990: Franklin, Jennifer; Loftin, Sam; Maddux, Troy; Murillo, Michelle; Shortess, Amy; Viers, Joran1991: Maddux, Troy; Loftin, Sam; Viers, Joran; McGee, Kathleen; Prichard, Susan1992: Maddux, Troy; Chavez, Melissa; Valdez, Monica; Bradley, Mike; Knight, Julie; Collier, Anthony; Persaud, Amanda; Ortiz, Ivan1993: Oriz, Ivan; Swanick, Raine; Taylor, Rob; Wagner, Natalie1994: Chavez, Melissa; Bocock, Jonathan; Altenbach, Marilyn; Yanoff, Steven; East, Micheal; Muckenhoupt, Jim; Budkovich, Pamela; Grant, Tom1995: Geer, Susan; Smith, Richard; Carpenter, Claire; Parker, Kelli; Giese, Kristy; Belden, Lisa; Weiss, Linda1996: Taugher, Kimberly; Belden, Lisa; Payne, Jennifer; Monteith, Nancy; Newingham, Beth Oldehoeft, Kim; Sexton, Jason1997: Taugher, Kimberly; Campbell, Mariel; Conn, Rachel; Kuehner, John; Helm, Amy; Kendall, John1998: Kuehner, John; Frasier, Jason; Korbe, Nicole; Kroll, AJ; Hayes, Betty; Hersch, ErikaMore information about when the data were collected: Spring 1989 Summer 1989dw 5/17/89-6/4/89 8/4/89-8/7/89fp 6/5/89-6/12/89 8/8/89-8/9/89sp 5/22/89-5/30/89 8/1/89-8/3/89vj 6/13/89-6/20/89 8/10/89-8/11/89 Spring 1990 Summer 1990All 5/23/90-6/14/90 All 8/6/90-9/5/90 Spring 1991 Summer 1991All 5/22/91-7/12/91 All 7/22/91-8/15/91 Spring 1992 Summer 1992All 6/3/92-6/18/92 7/28/92-8/6/92 Spring 1993 Summer 1993dw 5/27/93-5/31/93 7/14/93-7/20/93 fp 6/4/93-6/10/93 7/22/93-7/27/93vj 6/14/93-6/17/93 8/3/93-8/4/93rs 6/17/93-7/9/93 8/4/93-8/10/93bw 6/21/93-7/21/93 8/12/93-8/17/93sp 7/6/93-7/8/93 not measured Spring 1994 Summer1994 Fall 1994 dw 6/6/94 7/26/94 9/27/94-9/28/94 fp 6/8/94-6/9/94 8/2/94 9/29/94-10/3/94vj 6/20/94 8/1/94-8/2/94 10/5/94rs 5/31/94-6/3/94 7/25/94 10/6/94bw 6/15/94-6/16/94 8/4/94 10/10/94-10/11/94sp 6/23/94-6/27/94 8/9/94 10/13/94 Spring 1995 Fall 1995dw 5/25/95 10/2/95 fp 5/30/95 9/26/95vj 6/5/95 9/27/95rs 5/23/95 9/25/95bw 5/31/95 10/3/95sp 6/6/95 10/4/95 Spring 1996 Fall 1996dw 5/23/96 9/17/96 fp 5/27/96 9/19/96vj 6/5/96 10/8/96rs 5/29/96 9/25/96bw 6/13/96 10/2/96sp 6/3/96 9/30/96 Spring 1997 Fall 1997dw 6/10/97 10/2/97 fp 6/11/97 10/8/97vj 6/5/97 10/14/97rs 6/12/97 10/16/97bw 6/4/97 10/15/97sp 7/15/97 10/22/97 Spring 1998 Fall 1998dw 6/8/98 9/15/98 fp 6/1/98 9/17/98vj 6/15/98 9/16/98 rs 7/8/98 9/29/98bw 6/11/98 10/6/98sp 6/30/98 10/8/98
This data set contains information regarding carnivore scat surveys that were performed at sites in grama grassland and both creosote and mesquite shrubland habitats at the Sevilleta NWR. A total of nine surveys were carried out along road-based transects, each of which is a mile long, during one season in 2008 (June-July) and three seasons in 2009: spring (April-May), summer (July-August), and fall (October-November). There were 10 transects in grassland areas and 10 in shrubland areas in 2008. All 20 transects, as well as two additional transects in grassland areas, were surveyed in 2009. For more information on the structure of the vegetation surrounding these road based transects, see the "Vegetation surveys in grassland and shrubland sites that are associated with coyote scat surveys at the Sevilleta NWR, 2008-2009" data set. Scat samples were identified in the field and collected for genetic and stable carbon isotope analysis. Field recorded variables include: scat freshness, maximum diameter, length, and GPS coordinates, as well as the field-based species identification for the sample. Information on the lab based species and individual identification results are also presented.
This data was collected in order to obtain information on the size and feeding ecology of the coyote populations in grassland vs. shrubland habitats in three seasons (spring, summer and fall) and two years (2008 and 2009) at the Sevilleta NWR. A mark recapture analysis can be performed on the data from 2009 since two surveys were carried out for each scat transect in each of the three seasons and coyote scats were run through a genetic analysis to determine individual identity of the coyotes. A rough assessment of coyote habitat use can also be performed using the individual identity and coyote scat location information. Future isotope analysis will indicate whether the base of the food chain is C4 (grass) vs. C3 (shrubs) plants in grassland vs. shrubland habitats in each of the three seasons (spring (pre-monsoon), summer (monsoon) and fall (post monsoon)) and in each of two years (2008 and 2009).
Experimental Design: Carnivore scat surveys were carried out along roads located in grassland and shrubland habitats throughout the Sevilleta NWR. Surveys were done along 20 road based transects in 2008 and 22 transects in 2009. 10 transects were located in grassland areas and 10 in shrubland areas in 2008; there were 12 transects in grassland areas and 10 in shrubland areas in 2009.
Sampling Design: Each scat transect was 1 mile long and was separated from all other transects by at least 1 mile to ensure independence of scat samples collected on different transects. Each transect surveyed in 2008 (n=20) was surveyed a total of three times between June 24th and July 24th, 2008. Each transect surveyed in 2009 (n=22) was surveyed a total of six times between April 13th and November 6th, 2009. For 2009, two surveys were carried out in each of three seasons: spring (April-May 2009); summer (July-August 2009); and fall (October-November 2009).
Field methods: The beginning and end points of each scat transect were marked at the beginning of the summer field season in 2008, and then re-marked as necessary at the beginning of the spring field season 2009, with a wooden stake and a pin flag so that each of the three surveys in 2008 and six surveys in 2009 were carried out along the same road segments. The end points of three transects (D,E, and R) were moved slightly from their original locations in summer, 2008 and two transects were added (U and V) in 2009. The coordinates of all of these new locations were determined via GPS and recorded. Before the first scat survey in 2008, and before the first scat survey in each season in 2009, all transects were cleared of all visible carnivore scat. During each of the three subsequent surveys in 2008, and during the two subsequent surveys in each season in 2009, each complete carnivore scat sample encountered was measured and collected. A sample was considered to be incomplete if it were clearly torn or very small and likely missing part of the sample. When clearing transects and conducting surveys, the transects were driven in a field vehicle (truck) at 5-10mph and the driver looked through both the windshield and front windows for scat samples. In 2008, there was a second observer who would sit in the passenger seat and look through the windshield and front windows. When a particular item could not be identified from within the truck, the observer would get out of the vehicle and investigate the item further. When a carnivore scat sample was encountered, a photograph was taken and the GPS coordinates for the location of the scat were recorded. If the scat was composed of multiple pieces that were spread out along the road, then an attempt was made to record the GPS coordinates of a point midway between the two pieces that were furthest apart. If the scat was not flattened or otherwise degraded, two measurements of maximum diameter and one measurement of length were recorded. When a scat contained multiple pieces, these measurements were generally taken on the longest piece. If part of the scat was flattened, then measurements were taken on the longest, unflattened piece. Maximum diameter was measured using calipers and length was measured using a clear, plastic ruler. Once the measurements were taken, small pieces of the scat were removed using flame sterilized tweezers and placed in a 2mL plastic tube containing DET buffer. The buffer preserved the samples for future genetic analysis. The remainder of the sample was then collected in a ziplock bag for future drying and carbon isotope analysis.
All scat samples were dried for 24 hours at 70 degrees Celsius and, in future, will be prepared and run through a stable carbon isotope analysis in a coupled element analyzer and mass spectrometer. Small subsamples of each scat will be run through a mitochondrial DNA species test. All samples identified as coyotes in this test will then be run through a microsatellite analysis, with 8 loci, to identify individuals.
Data were recorded in the field and entered into a spreadsheet in Excel. Field recorded comments were removed since they did not add significantly to the value of the data and, in some cases, their importance or meaning would have been difficult to explain. No automated or quantitative data quality checks were performed.
Additional Information on the personnel associated with the Data Collection / Data Processing Other field crew members:Jon Erz and Teresa Seamster
In 1984, a research project was initiated on a relatively small disturbance patch just south of Deep Well. This disturbance was thought to be the result of an old praire dog town, probably dating back to when a nearby ranch was active, and a lot of old mammal mounds remained in the disturbed area. One of the things that made the disturbance patch particularily noticeable was the lush growth of snakeweed (Gutierrezia sarothrae) within the patch. This prompted the designation of the disturbance patch as the "snakeweed patch" or "gutierrezia patch". In addition, there was an obvious increase in bare ground and a shift in vegetation composition across the patch boundary. The dominant vegetation was not consistent around the boundary, with a marked dominance of black grama on the west side of the plot and a blue/black grama mix on the other three sides. To obtain information on the cause and/or effect of this disturbance, a survey of the soil and vegetation was performed.
In 1996, standard 100 m transects were set up parallel to the original vegetation transects and measured in a manner similar to SEV004 (Plant Line-Intercept Transects).
Transect set-up - A 100 m measuring tape was affixed to the 0 meter rebar stake (north) and run to the 100 meter (south) end of each of four transects. The tape was stretched as tight as possible to get the straightest line. Windy days were avoided to prevent the tape from billowing.
Recording data - Four crew members worked independently, each doing a 100 m segment simultaneously. Microcassette recorders and standard microcassettes were used to record data. At each 100 m segment, the following sequence was followed: Each species/substrate encountered along the line and the distance at which that species/substrate crossed the tape was recorded. Starting location only was recorded as the ending point was the starting point of the next species/substrate.
Coordinates (NAD27): End ofTransect Transect Latitude Longitude North 0 34 21' 1.2" 106 41' 8.3"W 100 34 20' 57.9"N 106 41' 8.6"W East 0 34 20' 47.0"N 106 41' 1.6"W 100 34 20' 46.5"N 106 41' 5.4"W West 0 34 20' 53.7"N 106 41' 16.3"W 100 34 20' 53.7"N 106 41' 12.4"W GCA 0 34 20' 49.1"N 106 41' 9.2"W 100 34 20' 45.6"N 106 41' 9.2"W
1996 REU's with assistance from the 1996 Field Crew.
This study explores the population dynamics of black-tail jackrabbits (Lepus californicus) and desert cottontail rabbits (Sylvilagus auduboni) in the grasslands and creosote shrublands of McKenzie Flats, Sevilleta National Wildlife Refuge. The study was initiated in January 1992, and continues quarterly each year. Rabbits are sampled via night-time spotlight transect sampling along the roads of McKenzie Flats once during winter, spring, summer, and fall. The route is 21.5 miles long. Measurements of perpendicular distance of each rabbit from the center of the road are used to estimate densities (number of rabbits per square kilometer) via Program DISTANCE. Results from January 1992 to May 2004 indicated that spring was the period of peak density period, with generally steady declines through the rest of the year until the following spring. Evidence of a long-term "cycle" (e.g., the 11-year-cycle reported for rabbits in the Great Basin Desert) does not appear in the Sevilleta rabbit populations.
The purpose of the study is to assess the dynamics of rabbit populations in the grasslands and creosote shrublands of the Sevilleta NWR. Rabbits are important herbivores in these habitats, and can influence net primary productivity and plant species composition. In turn, these animals also provide high-quality prey for many of the Sevilleta NWR's carnivores and birds of prey. Density data on rabbits can also be used to calculate herbivore pressure on the plant communities.
The rabbits are sampled along 21.5 miles of roadway that is broken up into four "legs" of varying lengths.
Leg A:Black Butte southward to Five Points (5.7 miles).
Leg B:Five Points eastward to the turnoff before Palo Duro Canyon (4.1 miles).
Leg D: McKenzie Headquarters site northwestward to Black Butte (5.6 miles).
Frequency of Sampling:
Sampled one night per season, four seasons per year.
Buckland, S. T., D. R. Anderson, K. P. Burnham, and J. L. Laake.1993. Distance Sampling. Estimating abundance of biological populations. Chapman and Hall, New York. 446 pp.
The rabbit surveys are conducted at night using spotlights positioned out each side of a pick-up truck. Surveys began one hour after sunset, when no trace of sunlight or dusk remained. Beginning in 1998, all surveys are conducted on or near the full moon.
The truck is driven slowly (8-10 miles per hour) along the 21.5 mile circuit. Two (or more) observers stand in the bed and scan the left and right sides (respectively) of the road with spotlights, while the driver keeps watch for rabbits directly in front of the vehicle.
During 1992, the spotlights were Q-Beam 500,000 candlepower spotting lights, with both flood and spot settings (spot settings were used during the rabbit sampling). From 1993 through 1996, Q-Beam spotlights with 1,000,000 candlepower were used. In 1997, new spotlights with 3,000,000 candlepower were used; these lights were set permanently on "flood", but illuminated distances previously reached by the spot settings of the less-powerful spotlights. SInce 2002, 2,000,000,000 candlepower spotlight gave been used.
In addition to the spotlights used by the standing observers in the bed of the pickup truck, two spotlights mounted on the pillar posts of the truck's cab are turned on and set for the roadsides ahead of the truck; these lights, coupled with the high-beam setting of the truck's headlights, illuminate the road in front of the truck for approximately 100 meters. When a rabbit is observed, one person's spotlight illuminates the spot at which the rabbit was first seen. The second person's spotlight tracks the rabbit so it is not counted twice. A meter tape is walked out from the center of the truck bed (i.e., the center of the road) perpendicular to the location at which the rabbit was first observed. That distance is measured and recorded to the nearest meter. If a rabbit is observed in the middle of the road, the distance is recorded as zero.
Beginning in Jan. 2000, perpendicular distances are measured using a laser range finder, with an accuracy of 1 meter. Accuracy level is checked prior to sampling. Generally, rabbits within 100 meters of the road can be seen relatively clearly with all three types of spotlights.
Other data recorded includes (1) the odometer reading in miles from the beginning of the sample at Black Butte (odometers are reset to zero at the start of the sample), (2) whether the rabbit was on the left or right side of the road, and (3) the species of rabbit. Incidental data on weather conditions is also noted including presence of clouds and moon, time at which the survey was begun, and times at which each leg was begun and finished. The names of the people on the sampling crew are also recorded.
Perpendicular distance data are entered into Program DISTANCE to estimate the total density of rabbits in the study area. Values are computed as numbers of individuals per square kilometer.
2,000,000,000 candlepower Q-Beam spotlights.
File created 23 Nov. 1992 - SM
1-30-95: 1-23-95 data entered by Rosemary Vigil.9-11-97: doc file created by Robert R. Parmenter 9-11-97: 4-25-95 through 8-4-97 data entered by Robert R. Parmenter 9-19-97: archived by Gregg MacKeigan as rabbit_survey_92-97.dbf. 10-29-97: data for 10-27-97 entered and checked by Robert R. Parmenter 2-6-00: data for 1998, 1999, and Jan. 2000 entered and checked by Robert R. Parmenter. 12-25-00: data for April, July, and October 2000 entered and checked by Robert R. Parmenter. 2-6-01: data for February 2001 entered and checked by Robert R. Parmenter. 2-5-02: data for April, July and October 2001, and January 2002, entered and checked by Robert R. Parmenter. 6-26-02: data for April, 2002, entered and checked by Robert R. Parmenter. 7-24-02: data for July, 2002, entered and checked by Robert R. Parmenter. 10-25-02: data for October, 2002, entered and checked by Robert R. Parmenter. 12-30-05: data for 2003 and 2004 entered and checked, and final edits to metadata file made by Robert R. Parmenter. doc
Dates of collection vary in some years, but sampling is generally conducted in January, April, July, and October.
The overall goal of the rainfall manipulation project is to understand the coupled ecological and hydrological responses of a grassland, shrubland and a mixed grass-shrub vegetation community to extended periods of increased or decreased rainfall. Rainfall manipulation plots have been established in each of these three vegetation communities in the Five Points area of Sevilleta National Wildlife Refuge. In each vegetation community, three control plots, three drought treatment plots, and three water addition plots have been installed, each approximately 10 x 15 m in size. In each plot, vertical profiles of soil moisture probes have been installed under each cover type (canopy and interspace in grassland and shrubland; grass canopy, shrub canopy and interspace at the ecotone (mixed grass-shrub) site). The probes measure differences in infiltration and soil water content and potential associations with these different cover types. In addition, TDR probes have been installed diagonally in each cover type to integrate the water content of the top 15 cm of soil. Each plot contains 18, 1m2 quads made up of 6, 1m2 quads along each of the 3 transects located across each plot. Each spring and fall, the following parameters are measured in every quad: live plant cover, height, and abundance by species; dead plant cover; soil cover; litter cover; and rock cover. Data collection began in the drought and control plots in the spring of 2002. Data collection began in the water addition plots in the spring of 2004.In the grassland and shrubland communities, all nine currently established plots are located together. The three drought plots were located under a single large roof with a 0.5 m path separating each plot (drought treatments ended in 2006). The control plots and water addition plots are similarly grouped, but without the shelter structure. In the ecotone community, the plots are in three groups; each group is comprised of one drought plot, one water addition plot, and one control plot. Control plots received no experimental treatment, while the sliding roofs over the drought plots were used to divert precipitation, producing a long-term drought. The roofs covering the drought plots were lowered when there was no precipitation so that the amount of sunlight received by the drought plots was minimally affected. Water addition was intended to impose a complementary increase in water supply on the water addition plots.
One meter2 vegetation quadrats are used to measure the cover and abundance of all plants present along each of the three transects across each plot. These quadrats are also used to measure dead plant foliage, leaf litter, bare soil, and rock covers. One person works on each quad, recording the data into a palm top computer. Two technicians may work independently along the same transect and alternate quadrats.
To begin quadrat measurements, first locate the three pairs of rebar along the length (across the slope, perpendicular to the gutter edge) of each plot, which mark the endpoints of each transect. Once the transect has been located, run a string across the plot attaching it to the two transect endpoint rebar stakes to act as a guideline for measurements. Each transect is measured from the left to the right side of the plot (where left and right are from the perspective of a person standing at the bottom edge of the plot where the gutters are located).
Beginning at the left side of the transect, place the bottom edge of the quadrat along the guidline of the string with the quad pointing away from the gutter edge. After measuring the quadrat, advance the quadrat along the transect by moving the quadrat to the right so that the bottom left corner is moved to the position formerly occupied by the bottom right corner. Repeat this process until the entire width of the transect has been measured. *Note: Beginning in the spring of 2010 only quadrats 2-7 (or meters 2-7) were measured. Before the spring of 2010 there were a variable number of quadrats measured per transect. If the last quadrat did not lie completely within the boundaries of the plot (within the metal edging), the percentage of the plot that lied within the plot boundary was recorded in the comments column of the data sheet and the vegetation data was recorded in the same manner as for the other quadrats. If the last quadrat lied completely within the boundaries of the plot, 100% was recorded in the comments section of the data sheet. This was to ensure that the entire transect had been measured.
General vegetation measurements
The cover, height, and abundance (standing biomass) are recorded for each species of plant inside the quadrat. Vegetation measurements are taken in two layers: a ground level layer that includes all grasses, forbs, sub-shrubs, the bases of Larrea tridentata and bare soil and a “shrub” layer that includes the canopy of Larrea tridentata. The purpose of this approach is to include Larrea canopies, while allowing the cover values of the ground level layer to sum to approximately 100%.
The quadrat boundaries are delineated by the 1 m2 PVC-frame placed above the quadrat. Each PVC-frame is divided into 100 squares with nylon string. The dimensions of each square are 10cm x 10cm and represent 1 % of the total quadrat area or cover. The cover and height of all individual plants of a species that fall within the 1m2 quadrat are measured. Cover is quantified by counting the number of 10cm x 10cm squares intercepted by all individual plants of a particular species, and/or partial cover for individual plants < 1%.
When reading plant cover it is important to stay centered over the vegetation in the quadrat. If you are not directly centered over the vegetation, cover measurements can be over or underestimated by your angle of view (parallax). If the surrounding plants prohibit you from leaning directly over the plants, use a tape measure to delineate a vertical column of intercept. To do this, simply extend the tape measure vertically from the base of the plant up to the frame grid.
Vegetation cover measurements
Cover measurements are made by summing the cover values for all individual plants of a given species that fall within an infinite vertical column that is defined by the inside edge of the PVC-frame. This includes vegetation that is rooted outside of the frame but has foliage that extends into the vertical column defined by the PVC-frame. Again, cover is quantified by counting the number of 10cm x 10cm squares intercepted by each species. Do not duplicate overlapping canopies, just record the total canopy cover on a horizontal plane when looking down on the quadrat through the grid.
Larger cover values will vary but the smallest cover value recorded should never be below 0.1%. When dealing with individual plants that are < 1.00%, round the measurements to an increment of 0.1. Cover values between 1.00 - 5.00% should be rounded to an increment of 0.5 and values > 5.00% are rounded to an increment of 5.
Cover measurements should be calculated separately for living and dead individuals of each species. However, because these measurements are made infrequently, vegetation should be considered live if it represents the current year’s growth (green and yellow). This is particularly important for grasses that may have become senescent during the fall sampling of each year.
Two Larrea tridentata coverage measurements are taken (LATR2 for canopy and LATR2B for the basal cover). The canopy level layer is estimated using the portion of the canopy that falls within the quadrat. The canopy edge is defined by a straight gravity line from the canopy to the ground (i.e. imagine a piece of string with a weight on the end being moved around the canopy edge). A basal cover is taken at the base of the shrub and includes all woody vegetation that stems from the ground. The purpose of taking two measurements for Larrea is to assess changes in shrub canopy cover without confounding the percent cover estimates of other species obtained using the basal layer. For Larrea seedlings the code LSEED is used and is a separate measurement from the Larrea canopy and basal measurements.
To determine the cover of a grass clump, envision a perimeter around the central mass or densest portion of the plant excluding individual long leaves, wispy ends or more open upper regions of the plant. Live tissue is frequently mixed with dead tissue in grass clumps. Provide two sets of measurements for the dead and live foliage, if possible, especially for perennial grass species. In the case that both live and dead are difficult to separate, measure all of the foliage as live. Remember that vegetation should be considered live if it represents the current year’s growth. In general, recently dead foliage is yellow and long-dead foliage is gray.
The cover of forbs is the perimeter around the densest portion of the plant. Measure all foliage that was produced during the current season including any recently dead (yellow) foliage.
Cacti and Yucca:
The cover of cacti and yucca is made by estimating a perimeter around the densest portion of the plant and recorded as a single cover. For cacti that consist of a cluster of pads or jointed stems (i.e., Opuntia phaecantha, Opuntia imbricata), estimate an average perimeter around the series of plant parts and record a single coverage measurement.
Vine cover (and some forbs) is often convoluted. Rather than attempt to estimate cover directly, take a frequency count of 10X10X10cm cubes that the vine is present in.
As with other vegetation measurements, the smallest cover value for seedlings should never be <0.1. If the value of seedling cover is less than 0.1, round up to 0.1. In the comments write “SEEDLING.”
Height is measured with a tape measure as a whole number in centimeters. All heights are vertical heights that are defined as a line parallel to the pull of gravity; this is not necessarily perpendicular to the ground if the ground is sloping. Measure the maximum height of each species identified in the quadrat. Do not measure the heights of every individual plant for a particular species.
The height of Larrea is only taken only at the canopy level (LATR2). Measure the maximum height from the base of the woody vegetation that stems from the ground to the top of the green foliage. No height measurement is needed at the basal level (LATR2B).
Annual grasses and all forbs:
Measure the height from the base of the plant to the tallest part of foliage for that species in the quadrat. Include the height of the inflorescence, if present.
Measure the height from the base of the plant to the tallest part of green foliage for that species in the quadrat. Do not include the inflorescence in the height measurement..
Plants rooted outside but hanging into the quadrat:
Do not measure the height from the ground. Measure only the height of the portion of the plant that is within the quadrat. In the comments section of the data sheet, record “Hang Over.” or “HO”.
Abundance is recorded as the number of individual plants that comprise the cover measurement. For some species, individuals are hard to distinguish. If there is bare space between two units, they should be considered separate individuals.
At the basal level (LATR2B) count the number of Larrea bases present in the quadrat.
Dead plant foliage:
For plants that are dead, but still attached to the soil and standing, just record the cover. Do not measure height or abundance for dead plants. Instead, record “-888” in these spaces on the spreadsheet to signify a value that was intentionally not recorded and enter DEAD in the comments. Cover is quantified by counting the number of 10cm x 10cm squares intercepted by each species. As with live vegetation, plant measurements that are < 1.00% should be rounded to an increment of 0.1. Cover values between 1.00 - 5.00% should be rounded to an increment of 0.5 and values > 5.00% are rounded to an increment of 5.
Remember, if some of the individuals of a plant species, or if portions of the foliage of an individual plant on the quadrat are dead and some alive, provide two sets of measurements for the dead and living foliage. In the case that both live and dead foliage are intermixed and difficult to separate, as in some bunch grasses and shrubs, just record the foliage as live. Any dead plant foliage that is not still attached to the roots and standing is considered leaf litter.
Materials other than vegetation that are measured in the drought plots include leaf litter, soil, rocks, and buckets (see below). Other than buckets, which occur in very few plots, values should always be recorded for these materials. If they are not present in a given quad, put ”-888” for their cover values so that it is clear that these categories were not simply overlooked during data collection.
Heights and abundances are not recorded for any of these materials. Instead, record “-888” for height and abundance and a numerical value for cover, where applicable (see below). If not recorded in the field, the data manager will do so during the QA/QC process.
Leaf litter includes all detached dead plant material on the soil surface, including woody branches. Cover is quantified by summing the number of 10cm x 10cm squares intercepted by patches of leaf litter. Cover values < 5.00% should be rounded to increments of 1 and cover values > 5.00% should be recorded in increments of 5. If there is no leaf litter in the quadrat, record “LITT” in the “species “ column and record “-888” in the cover, height, and abundance columns.
Some leaf litter cover has distinctive margins and is easy to define and measure. However, leaf litter may occur in 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 leaf litter cover. All leaf litter measurements are pooled into one observation, and no height or abundance is measured. Only measure leaf litter that is in the open, do not attempt to measure within clumps of grass, etc.
Measure the cover of the area occupied by abiotic substrates. Cover is quantified by summing the number of 10cm x 10cm squares intercepted by abiotic substrates. As with leaf litter, cover values < 5.00% should be rounded to increments of 1 and cover values > 5.00% should be recorded in increments of 5. If there is no soil in the quadrat, record “SOIL” in the species column for that quadrat and record a “-888” for the height, cover, and abundance. Again, when soil is present, only the cover is recorded and “-888” should be entered for height and count.
As a separate entry, estimate the cover of rock (particles >1 cm) occurring within the bare ground. The rock cover estimate can be viewed as an index of how much of the soil surface is rocky or as a subset of the soil cover measurement. The rock cover should still be measured as a sum of the number of 10cm x 10cm squares intercepted by rock. Cover values < 5.00% should be rounded to increments of 1 and cover values > 5.00% should be recorded in increments of 5. Enter “-888” for the height and count. If there is no rock cover in the quadrat, record “ROCK” in the species column and enter “-888” for the height, count, and cover.
For Grass and for Creosote sites treatments are: Plots 1-4 Drought; plots 5-6 Control; Plots 7-9 Watered; For Mixed site treatments are: Plots 3,6,9 Drought; Plots 2,4,8 Control; Plots 1,5,7 Watered.
File created 3/2/2005. -- Kristin VanderbiltUpdated 12/11/2006 --Karen Wetherill Data appended to file on 7/25/2005 -- KLV Data compiled into one file. Metadata entered in EML access database. TK 6 February 2009 data qa/qc in navicat. Made NONE measurements in the following format Cover 0 Height -888 Count -888. Corrected typos and errors. TLK 10 February 2009
On Aug 4, 2009, a lightning strike ignited a fire in the area west of the road from Black Butte to Five-Points. The fire started around 3:30 PM on the 4th. The fire was initially concentrated in the Grassland Drought, SMES, and Monsoon study areas. The next day the fire carried north and east to the Deep Well Meteorological station, Warming, and Nut-Net plot areas. The fire was finally contained by the end of the 5th covering >7800 ha.
Starting in the spring of 2011, only the mixed shrub site will be measured in the spring and in the fall only the mixed shrub and creosote sites will be measured. Measurements at the drought grassland site was discontinued at this time.
Sevilleta Field Crew Employee History
Megan McClung, April 2013-present, Stephanie Baker, October 2010-Present, John Mulhouse, August 2009-Present, Amaris Swann, August 25, 2008-January 2013, Maya Kapoor, August 9, 2003-January 21, 2005 and April 2010-March 2011, Terri Koontz, February 2000-August 2003 and August 2006-August 2010, Yang Xia, January 31, 2005-April 2009, Karen Wetherill, February 7, 2000-August 2009, Michell Thomey, September 3, 2005-August 2008, Jay McLeod, January 2006-August 2006, Charity Hall, January 31, 2005-January 3, 2006, Tessa Edelen, August 15, 2004-August 15, 2005, Seth Munson, September 9, 2002-June 2004, Caleb Hickman, September 9, 2002-November 15, 2004, Heather Simpson, August 2000-August 2002, Chris Roberts, September 2001-August 2002, Mike Friggens, 1999-September 2001, Shana Penington, February 2000-August 2000.
We evaluated the effects of a lightning-initiated fire on responses of vegetation communities. Following a fire in July 1998, 25 experimental plots were established on the eastern edge of MacKenzie Flats at the Sevilleta National Wildlife Refuge. Ten of these plots were located in a Bouteloua gracilis (blue grama)- dominated site, while 15 were established in another area dominated by Bouteloua eriopoda (black grama). We evaluated basal and aerial cover of all plant species at the community level using a vertical line point intercept method along transects within plots. Sampling was conducted immediately after the fire during the last week of July 1998, and again in September and October of 2001.
Experimental Design - Following a lightning-initiated fire in July 1998, 25 experimental plots were established on the eastern edge of MacKenzie Flats at the Sevilleta National Wildlife Refuge. Ten of these plots were located in a Bouteloua gracilis (blue grama)-dominated site, while 15 were established in another area dominated by Bouteloua eriopoda (black grama). In the former site, five of the 10 plots were established in burned areas, and the others were positioned in unburned grassland vegetation. In the latter site, five plots were placed in burned areas, five were positioned in unburned grasslands, and the five remaining plots were located in an area that contained a mix of burned and unburned patches of grassland vegetation.
Sampling Design - All of the plots in the Bouteloua gracilis-dominated site were 4 m x 16 m. Of the 25 plots where B. eriopoda was more abundant, nine were 4 m x 16 m and 16 were 4 m x 25 m. Regardless of site, all plots were oriented such that the long axis of each was parallel to a topographic gradient running east-west.
We sampled vegetation responses on two separate occasions. An initial sampling was conducted immediately after the fire during the last week of July 1998, and a final sample was conducted in September and October of 2001. During each of the two samples periods, four parallel transects were randomly positioned along the long axis of each plot. In 4 m x 16 m plots, transects were 12 m long, and 125 pins were vertically dropped every 10 cm along each transect. Transects were 25 m long in 4 x 25 m plots, and 125 pins were dropped every 20 cm along each transect.
Field Methods - Along each transect, vegetation community data were collected using the vertical point transect method (Bonham 1989). At each pin drop, all species that intercepted the pin were recorded in the order in which they were encountered from vegetation canopy to ground level. Additionally, we noted if a pin directly hit a plant species, bare ground, or litter.
The metadata and data were provided by Sandra Albro Rutter (email@example.com) and Paul Drewa at Case Western University. These data are not yet available to the public and are presently stored in an Excel file. Note that the last three variables in the attributes list are for the species abbreviations worksheet in the Excel file. The metadata were originally in a Word document. -- KLV
In an effort to better quantify NPP of Creosotebush in the Five-Points region, it was decided to test the Point-Quarter method against the standard 1-m2 quadrat method that has been in use since 1998. Transects were laid out across the 5 mammal trapping webs as well as across burned and unburned plots of the Mixed Shrub site (MS). Repeated measures of the same bushes are performed seasonally. Whole shrubs of various size classes are collected, sorted, and weighed to develop regressions for biomass.
Data was collected initially to determine density and dimensions of creosote bush in the Five points area on core rodent webs and on burned and unburned plots following the 2003 prescribed burn. It was decided to expand the project by continuing measurements through time to quantify the change in shrub size and with simultaneous harvest of shrubs to measure NPP.
Experimental Design The point-quarter technique is used to quantify the density of the shrubs at both the FivePoints Creosote and the Mixed Shrub (MS) sites. At the rodent webs two, 100 m transects are laid out across the diameter of each web. These transects were laid out using the existing trap locating rebar at 10 m intervals. The rebar used are those on the spoke running from 60 to 50 and then from 122 to 132 rebars at 5 m intervals. The stake at the center of the web is not used. This results in 20 points across each web or 80 shrubs per web.
At the mixed shrub site a different arrangement was used. Every other rebar was used along every other line as a measuring point. The rebars were also staggered by 1 rebar from line to line. Ultimately there were 12 rebars used in each plot for a total of 48 shrubs per plot.
Shrub Measurements In the initial sampling the shrub nearest the rebar in each quadrant was identified and the distance from the rebar to the rooting point of that shrub was measured. The height of the shrub was measured as well as the diameter of the crown at its widest point and also a diameter perpendicular to this first diameter. Repeated measures of the same bushes are performed seasonally.
July 2011- All new data were combined and QA/QC. No shrub measurements were taken in February of 2011 due to the fact that there was a shrub die off caused by extremely low temperatures on the refuge (-20F).--A. Swann
February 2009-All new data were combined and QA/QC. On web 4 at the creosote site, shrub 124 was measured twice because it was unknown about if it was one or two bushes and what had been measured in the past. It was identified that sometimes in the past two bushes instead of one was measured. Made note of this to reduce the chance of this happening in the future. At the mixed shrub unburned, shrub 114 and 132 are the same shrub. --A. Swann
January 2009 -All data from 2007 and 2008 were combined. Changed the order of variables on datasets to match metadata variable order. Went through the raw data and changed blank distances or ones with -99.00 to -888.00 to denote missing data. Changed missing data on height and weight due to plant being dead to -888. Changed missing data on height and weight due to human error to -999. -Imported excel raw data into Navicat using the wizard. --A. Swann
Data were scanned by eye to catch mistakes. Data were then filtered in excel to determine if all parameters were met.
Additional Information on the personnel associated with the Data Collection / Data Processing
In January 2011, the Sevilleta NWR experienced an extreme freeze with temperatures reaching below -25 degrees Celcius. These low temperatures negatively impacted the vegetation on the shrubs, resulting in the inablilty to measure the creosote shrubs during that season. Measurements were resumed the following spring of 2011.
Chandra Tucker, April 2014-present, Megan McClung, April 2013-present, Stephanie Baker, October 2010-Present, John Mulhouse, August 2009-June 2013, Amaris Swann, August 25, 2008-January 2013, Maya Kapoor, August 9, 2003-January 21, 2005 and April 2010-March 2011, Terri Koontz, February 2000-August 2003 and August 2006-August 2010, Yang Xia, January 31, 2005-April 2009, Karen Wetherill, February 7, 2000-August 2009, Michell Thomey, September 3, 2005-August 2008, Jay McLeod, January 2006-August 2006, Charity Hall, January 31, 2005-January 3, 2006, Tessa Edelen, August 15, 2004-August 15, 2005, Seth Munson, September 9, 2002-June 2004, Caleb Hickman, September 9, 2002-November 15, 2004, Heather Simpson, August 2000-August 2002, Chris Roberts, September 2001-August 2002, Mike Friggens, 1999-September 2001, Shana Penington, February 2000-August 2000.
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