This dataset is part of a long-term study at the Sevilleta LTER measuring net primary production (NPP) across four distinct ecosystems: creosote-dominant shrubland (Site C, est. winter 1999), black grama-dominant grassland (Site G, est. winter 1999), blue grama-dominant grassland (Site B, est. winter 2002), and pinon-juniper woodland (Site P, est. winter 2003). Net primary production is a fundamental ecological variable that quantifies rates of carbon consumption and fixation. Estimates of NPP are important in understanding energy flow at a community level as well as spatial and temporal responses to a range of ecological processes.
Above-ground net primary production is the change in plant biomass, represented by stems, flowers, fruit and and foliage, over time and incoporates growth as well as loss to death and decomposition. To measure this change the vegetation variables in this dataset, including species composition and the cover and height of individuals, are sampled twice yearly (spring and fall) at permanent 1m x 1m plots within each site. A third sampling at Site C is performed in the winter. The data from these plots is used to build regressions correlating biomass and volume via weights of select harvested species obtained in SEV157, "Net Primary Productivity (NPP) Weight Data." This biomass data is included in SEV182, "Seasonal Biomass and Seasonal and Annual NPP for Core Research Sites."
This dataset is designated as NA-US-011 in the Global Index of Vegetation-Plot Databases (GIVD). To aid tracking of the use of databases in this index, please also reference this number when citing this data. The GIVD report for SEV129 can be found in: Biodiversity and Ecology 4 - Vegetation Databases for the 21st Century (2012) by J. Dengler et al.
Locating the Sampling Quadrats:
Three core sites (B, G, and C) contain five rodent trapping webs. Each web consists of twelve 100m transects radiating out from a central rebar stake marked #145. There are four permanently marked ANPP plots on each of the trapping webs. These plots are located 10 meters from the end of the transects extending in the four cardinal directions. Each plot consists of four quadrats oriented around a tall center stake. Each quadrat is marked by two short, orange fiberglass stakes. Quad 1 is northwest of the center stake followed in a clockwise direction by quads 2, 3, and 4. As of 2004, only quads 1 (northwest of center stake) and 3 (southeast of center stake) are read at each plot.
Note: Winter measurements of all sites except Creosote (C) ceased after 2006.
Note: On August 4, 2009, some of the webs and quadrats within the unburned Black Grama (G) core site were impacted a lightning-initiated fire. Thus, webs 2 and 3 were abandoned and extra plots added to areas within webs 1, 4, and 5 that were not burned. Changes were as follows:
Webs 1, 4, and 5: A plot was added to the northeast to compensate for the loss of all plots at webs 2 and 3.
Web 4: A plot was added to the northwest to compensate for the northern plot, which was burned.
Note: At the blue grama/grassland study site, webs four and five are oblong rather than round. Therefore, the west and east plots are only 100 m apart.
Collecting the Data:
Net primary production data is collected twice each year, spring and fall, for all sites. The Five Points Creosote Core Site is also sampled in winter. Spring measurements are taken in April or May when shrubs and spring annuals have reached peak biomass. Fall measurements are taken in either September or October when summer annuals have reached peak biomass but prior to killing frosts. Winter measurements are taken in February before the onset of spring growth.
Vegetation data is collected on a palm top computer. A 1-m2 PVC-frame is placed over the fiberglass stakes that mark the diagonal corners of each quadrat. When measuring cover it is important to stay centered over the vegetation in the quadrat to prevent errors caused by angle of view (parallax). Each PVC-frame is divided into 100 squares with nylon string. The dimensions of each square are 10cm x 10cm and represent 1 percent of the total area.
The cover (area) and height of each individual live (green) vegetative unit that falls within the one square meter quadrat is measured. A vegetative unit consists of an individual size class (as defined by a unique cover and height) of a particular species within a quadrat. Cover is quantified by counting the number of 10cm x 10cm squares filled by each vegetative unit.
Niners and plexidecs are additional tools that help accurately determine the cover a vegetative unit. A niner is a small, hand-held PVC frame that can be used to measure canopies. Like the larger PVC frame it is divided into 10cm x 10cm squares, each square representing 1% of the total cover. However, there are only nine squares within the frame, hence the name “niner.” A plexidec can help determine the cover of vegetative units with covers less than 1%. Plexidecs are clear plastic squares that are held above vegetation. Each plexidec represents a cover of 0.5% and has smaller dimensions etched onto the surface that correspond to 0.01%, 0.05%, 0.1%, and 0.25% cover.
It is extremely important that cover and height measurements remain consistent over time to ensure that regressions based on this data remain valid. Field crew members should calibrate with each other to ensure that observer bias does not influence data collection.
Grasses-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 foliage is frequently mixed with dead foliage in grass clumps and this must be kept in mind during measurement as our goal is to measure only plant biomass for the current season. In general, recently dead foliage is yellow and dead foliage is gray. Within reason, try to include only yellow or green portions of the plant in cover measurement while excluding portions of the plant that are gray. This is particularly important for measurements made in the winter when there is little or no green foliage present. In winter, sometimes measurements will be based mainly on yellow foliage. Stoloniferous stems of grasses that are not rooted should be ignored. If a stem is rooted it should be recorded as a separate observation from the parent plant.
Forbs, shrubs and sub-shrubs (non-creosote)-The cover of forbs, shrubs and sub-shrubs is measured as the horizontal area of the plant. If the species is an annual it is acceptable to include the inflorescence in this measurement if it increases cover. If the species is a perennial, do not include the inflorescence as part of the cover measurement. Measure all foliage that was produced during the current season, including any recently dead (yellow) foliage. Avoid measuring gray foliage that died in a previous season.
Cacti-For cacti that consist of a series of pads or jointed stems (Opuntia phaecantha, Opuntia imbricata) measure the length and width of each pad to the nearest cm instead of cover and height. Cacti that occur as a dense ball/clump of stems (Opuntia leptocaulis) are measured using the same protocol as shrubs. Pincushion or hedgehog cacti (Escobaria vivipara, Schlerocactus intertextus, Echinocereus fendleri) that occur as single (or clustered) cylindrical stems are measured as a single cover.
Yuccas-Make separate observations for the leaves and caudex (thick basal stem). Break the observations into sections of leaves that are approximately the same height and record the cover as the perimeter around this group of leaf blades. The caudex is measured as a single cover. The thick leaves of yuccas make it difficult to make a cover measurement by centering yourself over the caudex of the plant. The cover of the caudex may be estimated by holding a niner next to it or using a tape measure to measure to approximate the area.
Height is recorded as a whole number in centimeters. All heights are vertical heights but they are not necessarily perpendicular to the ground if the ground is sloping.
Annual grasses and all forbs-Measure the height from the base of the plant to the top of the inflorescence (if present). Otherwise, measure to the top of the green foliage.
Perennial grasses-Measure the height from the base of the plant to the top of the live green foliage. Do not include the inflorescence in the height measurement. The presence of live green foliage may be difficult to see in the winter. Check carefully at the base of the plant for the presence of green foliage. If none is found it may be necessary to pull the leaf sheaths off of several plants outside the quadrat. From this you may be able to make some observations about where green foliage is likely to occur.
Perennial shrubs and sub-shrubs (non-creosote)-Measure the height from the base of the green foliage to the top of the green foliage, ignoring all bare stems. Do not measure to the ground unless the foliage reaches the ground.
Plants rooted outside but hanging into a quadrat-Do not measure the height from the ground. Measure only the height of the portion of the plant that is within the quadrat.
Creosote Measurements till 2013:
To measure creosote (i.e., Larrea tridenta) break the observations into two categories:
1.) Small, individual clusters of foliage on a branch (i.e., branch systems): Measure the horizontal cover of each live (i.e., green) foliage cluster, ignoring small open spaces (keeping in mind the 15% guideline stated above). Then measure the vertical "height" of each cluster from the top of the foliage to a plane created by extending a line horizontally from the bottom of the foliage. Each individual foliage cluster within a bush is considered a separate observation.
2.) Stems: Measure the length of each stem from the base to the beginning of live (i.e., green) foliage. Calculate the cumulative total of all stem measurements. This value is entered under "height" with the species as "stem" for each quadrat containing creosote. All other variable receive a default entry of "1" for creosote stem measurements.
Do not measure dead stems or areas of dead foliage. If in doubt about whether a stem is alive, scrape the stem with your fingernail and check for the presence of green cambium.
Creosote Measurements 2013 and after:
Each creosote is only measured as one total cover. Each quad that contains creosote will have one cover observation for each creosote canopy in quad.
Recording the Data:
Excel spreadsheets are used for data entry and file names should begin with the overall study (npp), followed by the date (mm.dd.yy) and the initials of the recorder (.abc). Finally, the site abbreviation should be added (i.e., c, g, b, p). The final format for sites B, G, and C should be as follows: npp_core.mm.dd.yy.abc.xls. For site P, the file format should be npp_pinj.mm.dd.yy.abc.xls. File names should be in lowercase.
01/12/2010 - Data was QA/QC'd and put in Navicat. Metadata was updated and compiled for 1999-2010. (JMM) 11/29/2009 - Data was QA/QC'd and put in Navicat. Metadata was updated and compiled for 1999-2009. Note: In fall of 2009, data from site G, webs 2, 3, and& 4 (plot N) was not collected due to unexpected fire at Sevilleta LTER sites. (YX) 01/05/2009 - Metadata was updated and compiled for 1999 - 2008. (YX) 01/06/2009 - As of 2007, winter season was no longer measured except at site C (creosotebush only). (YX) 12/05/2009 - NPP data from 1999-2008 was QA/QC'd in MySQL. 2006 (krw). In 2003, site B was added. In 2004, the number of quads was reduced to 40 per site (quads 2 and 4 at each plot are no longer read). I checked for duplicates and missing quads. These most often happened when a recorder mislabeled a particular quad. I also checked every plant code against the USDA Plants database online at http://plants.usda.gov/. All plant codes that have had nomenclature changes were updated. All previously unknown plants that have since been identified were also updated. All unknown plants that will never be identified were left in the database. All types were corrected. A list of codes not in the USDA list that are still in the data are as follows NONE = no plants in quad, OPUN = opuntia seedlings, SPOR = lumped Sporobolus spp (SPAI, SPCO4, SPCR, SPFL2), STEM = bare stem measurements for LATR2, U2 and UKFO18 and UKFO57 = unknowns that will never be identified, UKFO80 = unknown that has not yet been identified.A list of updates and the reason for the changes are below along with comments where identification is uncertain:OLD CODE,NEW CODE,NUMBER_ROWS_AFFECTED,REASON_FOR_CHANGEPOOL,POOL,2,TYPO-999,BOER4,3,ERROR_IN_DATA_MANAGEMENT ALLI1,ALMA4,2,IDENTIFIED_UKFO AMAR2,AMPA,8,IDENTIFIED_UKFO AMAR3,ACNE,9,IDENTIFIED_UKFO AMAR4,AMPA,4,IDENTIFIED_UKFO APIA1,CYMO,2,IDENTIFIED_UKFO ARDR4,ARLUL2,45,BELIEVED_MISIDENTIFICATION ARLUA,ARLUL2,3,BELIEVED_MISIDENTIFICATION ASTE13,SCMU6,31,IDENTIFIED_UKFO ASTE5,UKSH5,4,STILL_UNKNOWN ASTE7,TOAN,1,PROBABLE_IDENTIFICATION_FROM_UKFO_DESCRIPTION ASTRA,ASMIM,1,BEST_GUESS_FROM_DESCRIPTION BRAS1,LEDED,1,PROBABLE_IDENTIFICATION_FROM_UKFO_DESCRIPTION BRAS2,DRGL5,54,IDENTIFIED_UKFOBR BR2,BRCA3,4,ONLY_CHANGE_TO_BRCA3_AFTER_NEW_PJ_PLOT_DESIGN BREU,BREUC2,1,TYPO BRIC1,BRBR2,1,IDENTIFIED_UKFO BRIC3,BREUC2,5,IDENTIFIED_UKFO BRIC4,BREUC2,1,PROBABLE_IDENTIFICATION_FROM_UKFO_DESCRIPTION BRIC5,UKSH5,1,"KNOWN_FROM_LOCATION,_STILL_UNKNOWN" CACT,OPUN,4,"IN_ROW_ID_13908,_13919,_AND_184 47_CHANGE_COVER_TO_1,_THESE_ARE_LENGTH_BY_WIDTH_MEASUREMENTS,_OPUTIA_SPP_SEEDLINGS" CACT1,CACT1,0,NEVER_TO_BE_IDENTIFIED CADR6,HODR,630,NAME_CHANGE CAJA6,POJA5,8,NAME_CHANGE CHAL2,CHAL11,2,CODE_REDUNDANCY CHAM,CHMI7,1,IDENTIFIED_UKFO CHCO2,CHCO,5,ONLY_AT_SITE_MS CHEN1,TECO,58,IDENTIFIED_UKFO CHGO2,CHCO2,1,TYPO CHLA2,CHLA10,127,CODE_REDUNDANCY COAR4,VINE,10,"BAD_IDENTIFICATIONS,_I_RECOMMEND_LUMPING" COAU,COAU2,1,TYPO COEQ,VINE,3,"BAD_IDENTIFICATIONS,_I_RECOMMEND_LUMPING" CONV1,VINE,3,"BAD_IDENTIFICATIONS,_I_RECOMMEND_LUMPING" CONV3,VINE,7,"BAD_IDENTIFICATIONS,_I_RECOMMEND_LUMPING" CONV4,VINE,6,"BAD_IDENTIFICATIONS,_I_RECOMMEND_LUMPING" CRAB,PAOB,2,IDENTIFIED_UKFO CYMO,HYFIC,4,ONLY_AT_SITE_B DAJA,DABR,7,ONLY_AT_SITE_P DEOBO,DEPI,675,BELIEVED_MISIDENTIFICATION DEWO?,DEWO,1,CONFIRMED_ID ECFEF,ECCOC,2,BELIEVED_MISIDENTIFICATION ECFEF2,OPUN,1,ONLY_AT_PIS4 ECFEF2,ECCOC,3,ONLY_AT_SITE_P ECFEF2,ECFEF3,2,NAME_CHANGE ERCI,ERCI6,11,ONLY_ON_5/26/04_SITE_P ERCI6,ERCI,21,ALL_SITE_B ERDI2,ERFL,17,BELIEVED_MISIDENTIFICATION ERDI4,ERFL,32,BELIEVED_MISIDENTIFICATION ERRO2,ERPO4,1,ONLY_AT_SITE_P ERPU8,DAPU7,2006,NAME_CHANGE SCIND,ESVIV,3,ONLY_AT_MG EUGL3,CHGL13,1,NAME_CHANGE FABA1,LUBR2,1,PROBABLE_IDENTIFICATION_FROM_UKFO_DESCRIPTION FABA3,LOPL2,4,IDENTIFIED_UKFOF ORB1,FORB1,0,STILL_UNKNOWN FORB3,DIWI2,3,IDENTIFIED_UKFO GARR1,GACO5,2,IDENTIFIED_UKFO HEOB,HENA,9,BELIEVED_MISIDENTIFICATION HIJA,PLJA,1350,NAME_CHANGE HOGL2,HODR,985,BELIEVED_MISIDENTIFICATION HYVE,MILI3,1,ONLY_AT_SITE_P IPCO2,VINE,116,"BAD_IDENTIFICATIONS,_I_RECOMMEND_LUMPING" IPCO3,VINE,5,"BAD_IDENTIFICATIONS,_I_RECOMMEND_LUMPING" IPLE,VINE,1,"BAD_IDENTIFICATIONS,_I_RECOMMEND_LUMPING" IPLO,IPLO2,3,TYPO JF1,GACO5,2,PROBABLE_IDENTIFICATION_FROM_UKFO_DESCRIPTION JF3,PLPA2,13,PROBABLE_IDENTIFICATION_FROM_UKFO_DESCRIPTION JF5,POOL,1,MOST_COMMON_PORTULACA JG1,ARPUP6,2,PROBABLE_IDENTIFICATION_FROM_UKFO_DESCRIPTION JG2,BOGR2,4,"GRASS_SEEDLINGS,_LIKELY_BOGR2" JUM0,JUMO,1,SPELLED_WITH_A_ZERO KRLA,KRLA2,5,TYPO_NO_KRLA_AT_SITE_MS LARER,LAOCO,204,BELIEVED_MISIDENTIFICATION LITH1,LIIN2,3,IDENTIFIED_UKFO MAGR10,MAPIP,24,"BAD_IDENTIFICATIONS,_I_RECOMMEND_LUMPING" MIMU,MIOX,5,ONLY_FOR_P2R6 MUMI,MUTO2,1,QUESTIONABLE MUSQ,MOSQ,97,CODE_REDUNDANCY NEIN,ECIN2,12,NAME_CHANGE NYCT1,BOSP,1,IDENTIFIED_UKFO NYCT2,MILI3,14,IDENTIFIED_UKFO OEAL,OECAC2,17,"BAD_IDENTIFICATIONS,_I_RECOMMEND_LUMPING" OECEC2,OECAC2,806,CODE_REDUNDANCY ONAG1,GASUN,16,IDENTIFIED_UKFO OPEN,OPEN3,31,TYPO OPMAC,OPMA8,10,TYPO OPUN,OPUN,3,"IN_ROW_ID_19570,_20831,_AND_21055_CHANGE_COVER_TO_1,_THESE_ARE_LENGTH_BY_WIDTH_MEASUREMENTS,_OPUTIA_SPP_SEEDLINGS" OPUN1,OPUN,1,"IN_ROW_ID_38109,_THIS_IS_A_SEEDLING,_CHANGE_COVER_TO_1" PEPA20,SCPA10,1,NAME_CHANGE PF1,DRCUC,24,PROBABLE_IDENTIFICATION_FROM_UKFO_DESCRIPTION PF2,ARLUL2,15,PROBABLE_IDENTIFICATION_FROM_UKFO_DESCRIPTION PF3,PF3,0,NEVER_TO_BE_IDENTIFIED PF4,PF4,0,NEVER_TO_BE_IDENTIFIED PG1,HENE5,8,PROBABLE_IDENTIFICATION_FROM_UKFO_DESCRIPTION PHHEF,SOJA,3,"BAD_IDENTIFICATIONS,_I_RECOMMEND_LUMPING" POAC1,POAC1,0,NEVER_TO_BE_IDENTIFIED POAC11,POFE,25,PROBABLE_IDENTIFICATION_FROM_UKFO_DESCRIPTION POAC12,PAOB,3,IDENTIFIED_UKFO POAC14,POAC14,0,NEVER_TO_BE_IDENTIFIED POAC7,LYPH,3,IDENTIFIED_UKFO POLY1,CHGR2,98,IDENTIFIED_UKFO PORT1,POOL,1,MOST_COMMON_PORTULACA QUGR3,QUTU2,1244,"BAD_IDENTIFICATIONS,_I_RECOMMEND_LUMPING" SAKA,SATR12,588,BELIEVED_MISIDENTIFICATION SC?,SCPA10,1,GRAMA_CACTUS SCIND,ECIN2,19,NAME_CHANGE SCINI,ECIN2,46,BELIEVED_MISIDENTIFICATION SCSCN2,BOCU,8,BELIEVED_MISIDENTIFICATION SEED2,BELY,6,PROBABLE_IDENTIFICATION_FROM_UKFO_DESCRIPTION SOLA6,SOJA,14,IDENTIFIED_UKFO SOLA7,SOJA,2,IDENTIFIED_UKFO_PHHEF_LUMPED_WITH_SOJA SPAI,SPOR,39,ONLY_IN_SITE_P SPCO4,SPOR,2288,"BAD_IDENTIFICATIONS,_I_RECOMMEND_LUMPING" SPCR,SPOR,3603,"BAD_IDENTIFICATIONS,_I_RECOMMEND_LUMPING" SPFL2,SPOR,2485,"BAD_IDENTIFICATIONS,_I_RECOMMEND_LUMPING" SPHAE,SPWR,5,MOST_LIKELY_SPHAERALCEA SPORO,SPOR,2,"BAD_IDENTIFICATIONS,_I_RECOMMEND_LUMPING" STNE,HENE5,6,NAME_CHANGE STNE2,HENE5,72,NAME_CHANGE U1,MAFE,3,IDENTIFIED_UKFO U2,U2,0,NEVER_TO_BE_IDENTIFIED U3,U3,0,NEVER_TO_BE_IDENTIFIED U4,U4,0,NEVER_TO_BE_IDENTIFIED U5,VUOC,26,IDENTIFIED_UKFO U7,SCLA6,3,IDENTIFIED_UKFO UKAS2,ERFL,7,BEST_GUESS_FROM_DESCRIPTION UKCA,CHFE3,2,MOST_COMMON_CHAEMACYSE_IN_AREA UKCA1,MAHEH2,1,LOOKED_IN_FUTURE__DATA UKFO,SEDI3,1,BEST_GUESS_FROM_DESCRIPTION UKFO10,UKFO10,0,NEVER_TO_BE_IDENTIFIED UKFO13,UKFO13,0,NEVER_TO_BE_IDENTIFIED UKFO15,ARLUL2,2,PROBABLE_IDENTIFICATION_FROM_UKFO_DESCRIPTION UKFO16,BRBR2,3,IDENTIFIED_UKFO UKFO17,UKFO17,0,NEVER_TO_BE_IDENTIFIED UKFO18,UKFO18,0,NEVER_TO_BE_IDENTIFIED UKFO19,GUSA2,3,IDENTIFIED_UKFO UKFO20,SPLE,2,BEST_GUESS_FROM_DESCRIPTION UKFO21,DAJA,1,IDENTIFIED_UKFO UKFO22,SEDI3,1,IDENTIFIED_UKFO UKFO23,MESCS,1,IDENTIFIED_UKFO UKFO31,UKFO31,0,"COULD_BE_BADI,_GLWR_OR_NECA3" UKFO32,SACYH2,1,IDENTIFIED_UKFO UKFO51,UKFO51,0,NEVER_TO_BE_IDENTIFIED UKFO57,UKFO57,0,NEVER_TO_BE_IDENTIFIED UKFO61,THWR,186,IDENTIFIED_UKFO UKFO62,THWR,34,IDENTIFIED_UKFO UKFO7,ZIGR,2,IDENTIFIED_UKFO UKFO72,MILI3,27,PROBABLE_IDENTIFICATION_FROM_UKFO_DESCRIPTION UKFO72?,MILI3,1,PROBABLE_IDENTIFICATION_FROM_UKFO_DESCRIPTION UKFO73,HYVE,4,PROBABLE_IDENTIFICATION_FROM_UKFO_DESCRIPTION UKFO75,UKFO75,0,NEVER_TO_BE_IDENTIFIED UKFO76,UKFO75,3,NEVER_TO_BE_IDENTIFIED UKFO80,UKFO80,0,NOT_YET_IDENTIFIED UKGR2,LYPH,1,BEST_GUESS_FROM_DESCRIPTION UKSH1,SPLE,2,BEST_GUESS_FROM_DESCRIPTION UKSH4,BREUC2,8,IDENTIFIED_UKFO UKSH5,UKSH5,0,NOT_YET_IDENTIFIED
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).
Data updated 08/18/15: MOSQ changed to MUSQ3; ARPUP6 changed to ARPU9; SPWR changed to SPPO6; a single entry BOER changed to BOER4.