In 1989, line-intercept transects were installed to evaluate temporal and spatial dynamics across vegetation transition zones. Currently, a 400m transect is sampled at a grassland site (Deep Well) which is dominated by Bouteloua eriopoda (black grama) and, near the southern end of the transect, B. gracilis (blue grama). A second grassland site (Five Points), dominated by B. eriopoda and, to the south, Larrea tridentata (creosote), is also sampled. Both sites are sampled twice a year, in May/June and September/October, and measurements are taken at a one-centimeter resolution. The biannual sampling protocol detects potential responses in both cool and warm season plants as well as pre- and post-monsoon dynamics. Several transects have been discontinued and data archived within SEV200.
Preparing Transects for Measurement:
A 100m measuring tape is unrolled and affixed to permanent pieces of rebar hammered into the ground at each of the four segments of a 400 m transect. For example, a tape is attached to the 0 meter (north) rebar stake and run to the 100 meter (south) stake. The tape is stretched as tightly as possible to get the straightest line. Windy days should be avoided as the wind moves the tape and results in inaccurate data.
Crew members work independently, each doing a 100 m segment simultaneously. Microcassette recorders and standard microcassettes are used to record the data. File names should be written on the cassettes as "fp" (Five Points), "dw" (Deep Well), or "dwb" (Deep Well-burn) for the location, followed by the transect number, date, and initials of the recorder. An introductory statement is recorded on the cassette (e.g. "It's May 9, 2099, Joe Smith recording at Deep Well Transect 2."
Each species or substrate (i.e., bare soil, litter) that intersects the tape and occupies at least one centimeter is recorded whether rooted beneath the tape or not. Observations are recorded at the cm level, the point at which the species or substrate first crosses the tape being stated. This starting location is noted but the ending point is considered to be the starting point of the next species or substrate. For example, Bouteloua eriopoda encountered at 12m 79cm, litter encountered at 12m 82 cm, bare soil at 12m 85 cm, and so forth.
8/12/2010-The data in this file has been QA/QC'd and imported into MySQL. Unknown forbs were identified as UNKNO for the species code. (ALS) 12/08/2009-The data in this file has been QAQC'd in My SQL and on-line as well. Due to wildfire at Sevilleta LTER on Aug 5 2009, some plants were not identified. New variables were added, such as BGRASS (burned grass), BVEG (burned vegetation), BSHRUB (burned shrub), and BFORB(burned forb). We will replace those variables when we can identify them in the following seasons. (YX) 12/20/2008-The data has been QAQC'd in My SQL. All plant codes have been updated to current Kartesz codes as listed in the USDA Plants Database found at http://plants.usda.gov/. Questionable identifications and mistakes were updated to the best of my (data manager's) ability. Old codes are maintained in the database and can be obtained by contacting the data manager. (KRW)
Changes to the data: This dataset (SEV004) includes all active line intercept data from Transect 1 at both Deep Well and Five Points. Old species codes are maintained in the database and can be obtained by contacting the data manager. Old data and metadata can be found in: /export/db/local/htdocs/data/archive/plant/transect/data_oldformat but this data has NOT been vigorously QAQC'd and contains errors. Contact the Sevilleta LTER data manager for data and metadata in this older format.
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, Deep Well Line Intercept transect, and Nut-Net plot areas. The fire was finally contained by the end of the 5th covering >7800 ha.
Other researchers involved with collecting samples/data: Chandra Tucker (CAT; 04/2014-present), Megan McClung (MAM; 04/2013-present), Stephanie Baker (SRB; 09/2010-present), John Mulhouse (JMM; 08/2009-06/2013), Amaris Swann (ALS; 08/2008-01/2013), Maya Kapoor (MLK; 08/2003-01/2005, 05/2010-03/2011), Terri Koontz (TLK; 02/2000-08/2003, 08/2006-08/2010), Yang Xia (YX; 01/2005-03/2010), Karen Wetherill (KRW; 02/2000-08/2009); Michell Thomey (MLT; 09/2005-08/2008), Heather Simpson (HLS; 08/2000-08/2002), Chris Roberts (CR; 09/2001-08/2002), Shana Penington (SBP; 01/2000-08/2000), Seth Munson (SMM; 09/2002-06/2004), Jay McLeod (JRM; 01/2006-08/2006); Caleb Hickman (CRH; 09/2002-11/2004), Charity Hall (CLH; 01/2005-01/2006), Mike Friggens (MTF; 1999-09/2001), Tessa Edelen (MTE, 08/2004-08/2005).
ARPUP6 changed to ARPU9 03/05/2015; SPWR changed to SPPO6 03/05/2015