In 2005, annually harvested root ingrowth donut structures were co-located with previously established mini-rhizotron tubes established at four sites on McKenzie Flats located on the east side of Sevilleta NWR: 10 replicate structures in both burned and unburned blue and black grama dominated grassland plots at Deep Well, 10 replicates each on nitrogen fertilization plots and respective control plots on McKenzie Flats(20 total), 10 replicates in creosote dominated shrubland at the Five Points Creosote Core site and in 2011, 13 structures were put in the Monsoon site. Roots and soil are harvested annually in late fall after the growing season, and structures are reestablished in situ for consecutive harvests each year. Each structure allows roots to be harvested at two depths (0-15 and 15-30 cm) to estimate root production, or below ground net primary productivity. In order to compare estimates of root production from two methods, root ingrowth donuts were collocated with mini-rhizotron tubes at all localities except for the burned grassland plot at Deep Well.
Experimental Design Annually harvested root ingrowth donut structures are co-located with previously established mini-rhizotron tubes established at four sites on the McKenzie Flats on the east side of Sevilleta NWR: 10 replicate structures in both burned and unburned blue and black grama dominated grassland plots at Deep Well, 10 replicates each on nitrogen fertilization plots and respective control plots on McKenzie Flats (20 total), and 10 replicates in creosote dominated shrubland at the Five Points Creosote Core site. Methods were adapted from Milchunas et al (2005). We use a formidable 10 diameter soil core to create cylindrical holes in the ground to a depth of 30cm without disturbing soil profile at the cylinder walls. The soil core was inserted with a slide hammer and had to be removed each time with a come-along mounted on a steel-pipe tripod. Walls were subsequently lined with plastic cross-stitch craft work canvas (macram mesh) which supports cylinder walls through time but allows roots to pass through. Two pieces of 6 diameter PVC were placed in the center of the larger cylindrical hole, set in place with bags filled with sand that act as ballasts. The two pieces of PVC were beveled on opposite ends to fit together and prevent movement of the donut center. The top cylinder went to a depth of 15 cm and the bottom piece went to a depth of 30 cm, representing 0-15 and 15-30 cm in the soil profile when stacked upon one another. Finally, sifted soil from the location was used to fill the space between the plastic canvas lining the hole wall and the PVC pipe placed in the center. It is this soil which is harvested annually at two depths. A PVC cap was placed on top of the PVC to eliminate water infiltration from rain through the donut center and to keep sunlight from disintegrating the sand bag ballast. All root ingrowth donuts were GPSed.
Sample Harvest Root donuts are harvested annually in November after the growing season. Roots are harvested by first removing the sand bags from the top cylinder and placing a bowl into the center of the cylinder. The top cylinder is then removed. Soil and roots are cut away from the cylinder wall and collected. This harvest procedure is then repeated for the lower half of the donut structure. Soil and roots collected are placed in a separate plastic bag for each depth. Once the soil and roots are harvested, the root ingrowth structure is rebuilt. After harvest, soil and root samples are stored in a chest freezer until they can be processed.
Sample Processing The total volume of soil from each sample is measured and recorded. Soils are filtered through a series of sieves in which to harvest the roots present in the sample. The roots are then repeatedly rinsed to remove all the soil from the sample, dried at 60 degrees C, and then weighed.
23 Jan 2009All data sets (2005-2008) were combined and checked for errors in excel and exported into Navicat. From the 2007 data, I converted the dry root mass from grams to milligrams and changed depth data to be 0-15 and 15-30 cm. QA/QC'd data. I deleted data line from DWB sample 7, depth 15-30 cm with volume 2600 ml because it was a duplicate. I also changed the depth of DWB sample 12, depth 15-30 cm with volume 2000 to the depth 0-15 cm because the depth 15-30 cm was duplicated. -Changed missing data on volume and weight due to plant being dead to -888. -Changed missing data on volume and weight due to human error to -999. --A. Swann
Filtered data in Excel then exported it into Navicat using the import wizard.
Additional Information on the personnel associated with the Data Collection / Data Processing
Sevilleta Field Crew Employee History
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.