permanent plots

Core Site Grid Quadrat Data for the Net Primary Production Study at the Sevilleta National Wildlife Refuge, New Mexico (2013- present)

Abstract: 

Begun in spring 2013, this project is part of a long-term study at the Sevilleta LTER measuring net primary production (NPP) across three distinct ecosystems: creosote-dominant shrubland (Site C), black grama-dominant grassland (Site G), and blue grama-dominant grassland (Site B). 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 SEV999, "Net Primary Productivity (NPP) Weight Data." This biomass data is included in SEV999, "Seasonal Biomass and Seasonal and Annual NPP for Core Grid Research Sites."

Data set ID: 

289

Additional Project roles: 

450
451
452
453

Keywords: 

Methods: 

Sampling Quadrats:

Each sampling grid contains 40 1x1m quadrats in a 5x8 array. However, only 30 quadrats are sampled at each. These are quadrats 1-15 and 26-40. Thus, the middle two rows (i.e., 10 quadrats) are not sampled. Locating the Sampling Quadrats: Three core sites (B, G, and C) contain five rodent trapping and vegetation sampling webs. The vegetation grids are near these webs at each core site. At the blue grama site, the grid is located at the southern end of web 5, between webs 2 and 4. At the creosote site, the grid is east of web 3, near the road. At the black grama site, the grid is just northeast of web 5.

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.

Cover Measurements:

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 phaecanthaOpuntia 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 viviparaSchlerocactus intertextusEchinocereus 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 Measurements:

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, "g" for "grid," along with the site abbreviation, should be added (i.e., gc, gg, gb). The final format for sites B, G, and C should be as follows: npp_core.mm.dd.yy.abgg.xls. File names should be in lowercase.

Data sources: 

sev289_nppgridquadrat_20161214.csv

Additional information: 

Other researchers involved with collecting samples/data: Chandra Tucker (CAT; 04/2014-present), Megan McClung (MAM; 04/2013-present), Stephanie Baker (SRB; 2013-present), John Mulhouse (JMM; 08/2009-06/2013).

Pinon-Juniper (Core Site) Quadrat Data for the Net Primary Production Study at the Sevilleta National Wildlife Refuge, New Mexico (2003-present )

Abstract: 

This dataset contains pinon-juniper woodland quadrat data and 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."

Data set ID: 

278

Core Areas: 

Additional Project roles: 

458
459
460
461

Keywords: 

Methods: 

Locating the Sampling Quadrats:

Site P, the pinon-juniper woodland site (Cerro Montosa), is set-up differently than the other core sites. In order to accommodate the different habitat types, groups of transects (i.e., "plots") were set up along north (N) and south (S) facing slopes as well as along vegas (V) and ridges (R). Transects on the first two plots consist of 40 quads each (10 quadrants for each of four habitat types). Plot one is slightly west of plot three and plot two is slightly west of the weather station. Plot three is located on a wide piedmont, which consists of four transects with five quadrats on each.

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.

Cover Measurements:

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 Measurements:

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:

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.

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.

Data sources: 

sev278_npppinjquadrat_20161214.csv

Additional information: 

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), Tessa Edelen (MTE, 08/2004 - 08/2005).

Data updated 08/18/15: MOSQ changed to MUSQ3; ARPUP6 changed to ARPU9; SPWR changed to SPPO6; ambiguous Quercus species resolved by New Mexico Natural Heritage Program and updated.

Burn Study Sites Quadrat Data for the Net Primary Production Study at the Sevilleta National Wildlife Refuge, New Mexico (2004-present)

Abstract: 

In 2003, the U.S. Fish and Wildlife Service conducted a prescribed burn over a large part of the northeastern corner of the Sevilleta National Wildlife Refuge. Following this burn, a study was designed to look at the effect of fire on above-ground net primary productivity (ANPP) (i.e., the change in plant biomass, represented by stems, flowers, fruit and foliage, over time) within three different vegetation types: mixed grass (MG), mixed shrub (MS) and black grama (G). Forty permanent 1m x 1m plots were installed in both burned and unburned (i.e., control) sections of each habitat type. The core black grama site included in SEV129 is used as a G control site for analyses and does not appear in this dataset. The MG control site caught fire unexpectedly in the fall of 2009 and some plots were subsequently moved to the south. For details of how the fire affected plot placement, see Methods below. In spring 2010, sampling of plots 16-25 was discontinued at the MG (burned and control) and G (burned treatment only) sites, reducing the number of sampled plots to 30 at each.

To measure ANPP (i.e., the change in plant biomass, represented by stems, flowers, fruit and foliage, over time), the vegetation variables in this dataset, including species composition and the cover and height of individuals, are sampled twice yearly (spring and fall) at each plot. 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 SEV185, "Burn Study Sites Seasonal Biomass and Seasonal and Annual NPP Data."

Core Areas: 

Data set ID: 

156

Additional Project roles: 

438
439
440
441

Keywords: 

Data sources: 

sev156_nppburnquadrat_20161214.csv

Methods: 

Collecting the Data:

Net primary production data is collected three times each year, winter, spring, and fall, for all burn sites. 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 and only creosote is measured.

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. It is possible to obtain a total percent cover greater than 100% for a given quadrat because vegetative units for different species often overlap.

Niners and plexidecs are additional tools that can 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

Cover Measurements:

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 centimeter 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 Measurements:

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 shrub 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., mg, ms, or g). The final format should be as follows: npp_burn.mm.dd.yy.abc.xls. File names should be in lowercase.

August 2009 Burn:

On August 4, 2009, a lightning-initiated fire began on the Sevilleta National Wildlife Refuge.  The fire reached the Mixed-Grass Unburned plots on August 5, 2009, consuming them in their entirety.  As a result, in the spring of 2010, the Mixed-Grass (MG) unburned plots were moved to a different area within Deep Well, southwest of the Warming site. 

Also, on August 4, 2009, some of the webs and quadrats within the unburned Black Grama (G) site were impacted by the 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.

Maintenance: 

01/13/2011-Burn NPP quad data was QA/QC'd and put in Navicat. Matadata updated and compiled from 2004-2010. The mixed-grass unburned plot was moved to the south after the original plot burned unexpectedly in the fire of August 2009. (JMM) 11/28/2009-Burn NPP quad data was QA/QC'd and put in Navicat. Metadata updated and complied from 2004-2009. Mixed-grass unburned data (Fall 2009) was not collected due to unexpected fire at Sevilleta LTER in Aug 2009. (YX) 01/14/09-Metadata updated and compiled from 2004-2008 data. As of 2007, winter measurements are longer being taken. (YX) 12/20/2008-This data was QAQC'd in MySQL. I checked for duplicates and missing quads. (YX)

Additional information: 

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; 08/2010-04/2013), 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); 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); 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.

Plant Removal Study: Recovery of Vegetation Following Disturbance at the Sevilleta National Wildlife Refuge, New Mexico (1995-present)

Abstract: 

In 1995, a removal study was initiated at the Sevilleta LTER to examine the response of vegetation following the removal of dominant species. Five sites were selected that were dominated by either blue grama (site 1), blue and black grama (site 2), black grama (site 3), black grama and creosote (site 4), or creosote (site 5). A sixth site was later added in the blue grama community along the foothills of the Los Pinos Mountains (site 6). At sites 1, 3, 5, and 6, five 3m x 4m plots had all plants of the dominant species removed; five 3m x 4m plots were controls. At site 2, 5 plots had blue grama removed, 5 plots had black grama removed, and 5 plots were controls. At site 4, 5 plots had black grama removed, 5 plots had creosote removed, and 5 plots were controls. Initial cover prior to removal was estimated by species for each plot. Grass was removed using a shovel to collect above-ground biomass and crowns just below the soil surface. Shrubs were removed using large clippers to collect above-ground biomass to the soil surface. All biomass removed was bagged, dried, and weighed. Plot maintenance or removal of the target dominant species is performed annually or as needed. Rain gauges were installed at each site and the corners of the areas containing each set of plots GPS'd. Plot corners are marked by nails and are flagged periodically to aid identification and minimize foot traffic in the plots. Each northeast nail has a metal tag with site and plot number on it. Erosion bridges (1 m long) were installed in plots 1, 3 and 5 (removals and controls) at sites 1-5. Initial measurements were made in 1996.

Core Areas: 

Data set ID: 

168

Keywords: 

Methods: 

Collecting the Data:

Each fall, during peak biomass (late Aug.-early Oct.), species richness and cover are visually observed in each plot. Data are entered onto a palmtop using the pre-formatted spreadsheet for ease of entry and transfer to a PC. The procedure is as follows:

1. Locate the metal tag on the northeastern nail and enter the site and plot code into the palmtop.

2. Depending on the treatment, certain species may need to be removed in and around the plot. The removal codes are as follows: RU-Remove BOGR2, RA-Remove BOER4, and RC-Remove LATR2. Do not remove plants from the control (C) and total removal (TR) plots.

3. Thoroughly search each plot and record every species present. This is ideally done by 1-2 people, but a single observer is sufficient.

4. The percent canopy cover of each species in the plot is estimated visually using the following numerical ranges:

T = < 0.1%

0.1-0.9% by intervals of 0.1%

1-5% by intervals of 0.5%

5-20% by intervals of 1.0%

20-100% by intervals of 5.0%

Cover is estimated for all species as well as litter. Bare ground is calculated by subtracting the total cover of all species from 100%. Cover of less than 0.1% is recorded in the data as "T" (i.e., trace).

It is advisable to re-flag plot corners and perform plot maintenance prior to assessing cover. To maintain the plots, clip any species to be removed from the edges and middle of the plot. Do not re-clip anything from the total removal plots.

Laboratory procedures:

Biomass removed from plots is dried, sorted by live and dead material, and weighed.

Data description:

In some years, dates of data collection were lost. -999 has been entered for "Date" in such instances.

Also, in 1996, data was collected in both the summer and fall. Therefore, the 1996 data represents the maximum cover of a species observed that year, regardless of sampling period.

Data sources: 

sev168_removal_20160324.txt

Maintenance: 

Data QA/QC'd and uploaded. Metadata completed for 2010. 11/10/10 (JMM) Data QA/QC'd and uploaded. Metadata updated and completed for years 1996-2009. 3/15/10 (JMM) Metadata completed for years 1996-2008.  3/6/09 (TLK)

Additional information: 

Other researchers involved with collecting samples/data: Chandra Tucker (CAT; 04/2014-present), Megan McClung (MAM; 01/2013-present), Stephanie Baker (SRB; 10/2010-present), John Mulhouse (JMM; 08/2010-06/2013), 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).

Due to government shutdown in Fall of 2013, this data was not able to be collected. 

Warming-El Nino-Nitrogen Deposition Experiment (WENNDEx): Seasonal Biomass and Seasonal and Annual NPP at the Sevilleta National Wildlife Refuge, New Mexico (2006-present)

Abstract: 

Begun in winter 2006, this long-term study at the Sevilleta LTER examines how heightened winter precipitation, N addition, and warmer nighttime temperatures affect above-ground biomass production (ANPP) in a mixed desert-grassland. 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.  While measures of both below- and above-ground biomass are important in estimating total NPP, this study focuses on above-ground net primary production (ANPP). Above-ground net primary production is the change in plant biomass, including loss to death and decomposition, over a given period of time. Volumetric measurements are made using vegetation data from permanent plots (SEV176, "Warming-El Nino-Nitrogen Deposition Experiment (WENNDEx): Net Primary Production Quadrat Data") and regressions correlating species biomass and volume constructed using seasonal harvest weights from SEV157, "Net Primary Productivity (NPP) Weight Data."

Core Areas: 

Data set ID: 

205

Additional Project roles: 

417
418
419
420

Keywords: 

Data sources: 

sev205_warmingbiomass_20150814

Methods: 

Derivation of Biomass and NPP:

Data from SEV176 and SEV157 are used to calculate seasonal and annual production of each species in each quadrat for a given year. Allometric equations derived from harvested samples of each species for each season are applied to the measured cover, height, and count of each species in each quadrat. This provides seasonal biomass for spring and and fall.

Seasonal NPP is derived by subtracting the previous season's biomass from the biomass for the current season. For example, spring NPP is calculated by subtracting the winter weight from the spring weight for each species in a given quadrat. Negative differences are considered to be 0. Likewise, fall production is computed by subtracting spring biomass from fall biomass. Annual biomass is taken as the sum of spring and fall NPP.

August 2009 Burn:

On August 4, 2009, a lightning-initiated fire began on the Sevilleta National Wildlife Refuge. By August 5, 2009, the fire had reached the Warming site, which was burned extensively though not entirely. Approximately 50% of plots burned on August 5 and those plots which did not burn were burned within three weeks by US Fish and Wildlife.  Thus, the condition of all plots at the Warming site was comparable by early September 2009.

Maintenance: 

02/06/09 (YX) Metadata created and compiled for 2006, 2007, 2008 data. From 2007, winter measurements are no longer taken.

Additional information: 

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; 08/2010-06/2013), 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).

Core Research Site Web Quadrat Data for the Net Primary Production Study at the Sevilleta National Wildlife Refuge, New Mexico (1999-present)

Abstract: 

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.

Core Areas: 

Data set ID: 

129

Additional Project roles: 

430
431
432

Keywords: 

Data sources: 

sev129_nppcorequadrat_20170621

Methods: 

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.

Cover Measurements:

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 Measurements:

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.

Maintenance: 

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

Additional information: 

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.

Pinon Juniper Net Primary Production Quadrat Data from the Sevilleta National Wildlife Refuge, New Mexico: 1999-2001

Abstract: 

This three-year study at the Sevilleta LTER was designed to monitor net primary production (NPP) across two distinct ecosystems: pinon/juniper woodland (P) and juniper savannah woodland (J). Net primary production (NPP) is a fundamental ecological variable that measures 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 of the community to a wide range of ecological processes. While measures of both below- and above-ground biomass are important in estimating NPP, this study focused on estimating above-ground biomass production (ANPP).

To measure ANPP (i.e., the change in plant biomass, represented by stems, flowers, fruit and foliage, over time), the vegetation variables in this dataset, including species composition and the cover and height of individuals, were sampled twice yearly (spring and fall) at permanent 1m x 1m plots. The data from these plots was used to build regressions correlating biomass and volume via weights of select harvested species obtained in SEV157, "Net Primary Productivity (NPP) Weight Data." In addition, volumetric measurements were obtained from permanent plots to build regressions correlating biomass and volume.

Spring measurements were taken in April or May when shrubs and spring annuals reached peak biomass. Fall measurements were taken in either September or October when summer annuals reached peak biomass but prior to killing frosts. Winter measurements were taken in February before the onset of spring growth.

Core Areas: 

Data set ID: 

187

Additional Project roles: 

36

Keywords: 

Data sources: 

sev187_pjnppquadrat_04122010

Methods: 

Collecting the Data:

Vegetation data is collected on a palm top computer. 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 should be as follows: npp.mm.dd.yy.abcg.xls. File names should be in lowercase.

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.

Cover Measurements:

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-The cover of forbs is measured as the perimeter of the densest portion of the plant. If the forb is an annual it is acceptable to include the inflorescence in this measurement. If the forb 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 Measurements:

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 shrub and sub-shrubs-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.

Foliage canopy cover:

Cover and height are recorded for all separate vegetative units that fall within an infinite vertical column that is defined by the inside edge of the PVC-frame. A vegetative unit consists of an individual species with a unique cover and height. This includes vegetation that is rooted outside of the frame but has foliage that extends into the vertical column defined by the PVC-frame.

As mentioned above, cover is quantified by counting the number or fraction of 10 cm x 10 cm squares intercepted by each vegetative unit. It is possible to obtain a total percent cover greater than 100 for a quadrat because vegetative units often overlap (especially in shrubs and succulents). For perennial plants, cover is based only on the vegetative portion of the plant (stem and leaf). For annual plants, cover is based on both vegetative and reproductive (inflorescence) portions of the plant.

If the cover of a vegetative unit is less than 1, the increments used are as follows: 0.01, 0.05, 0.1, 0.25, 0.5, and 0.75. If cover is between 1 and 5, increments of 0.5 are used and, if greater than 5, increments of 1 are used.  Finally, if the cover is greater than 15, the total canopy cover is divided into smaller units and the cover and heights of each observation measured separately. This reduces the size of harvest samples.

Maintenance: 

January 7, 2008 KRW Data from the P and J sites from 1999 to 2002 were extracted from the ongoing npp database and put in its own table in navicat. Palmtop/pj_npp. NPP data from 1999-2001 was QAQC'd in MySQL. 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 are that are still in the data are as follows NONE = no plants in quad, and UKFO57 = unknowns that will never be identified, UKFO80 = unknown that has not yet been identified. A list of the updates and the reason for the change are in the table below along with comments where identifications were questionable.

Additional information: 

Employee History:Mike Friggens: 1999 to September 2001, Karen Wetherill: February 7, 2000 to August 2009, Terri Koontz: February 2000 to August 2003 and August 2006 to August 2010, Shana Penington: February 2000 to August 2000, Heather Simpson: August 2000 to August 2002, Chris Roberts: September 2001 to August 2002.

Monsoon Rainfall Manipulation Experiment (MRME): Net Primary Production Quadrat Data at the Sevilleta National Wildlife Refuge, New Mexico (2006-present)

Abstract: 

The Monsoon Rainfall Manipulation Experiment (MRME) is to understand changes in ecosystem structure and function of a semiarid grassland caused by increased precipitation variability, which alters the pulses of soil moisture that drive primary productivity, community composition, and ecosystem functioning. The overarching hypothesis being tested is that changes in event size and variability will alter grassland productivity, ecosystem processes, and plant community dynamics. In particular, we predict that many small events will increase soil CO2 effluxes by stimulating microbial processes but not plant growth, whereas a small number of large events will increase aboveground net primary production (ANPP) and soil respiration by providing sufficient deep soil moisture to sustain plant growth for longer periods of time during the summer monsoon.

To measure ANPP (i.e., the change in plant biomass, represented by stems, flowers, fruit and foliage, over time), 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. 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 SEV206, "Seasonal Biomass and Seasonal and Annual NPP for the Monsoon (MRME) Study."

Core Areas: 

Data set ID: 

188

Additional Project roles: 

454
455
456
457

Keywords: 

Data sources: 

sev188_nppmonsoonquadrat_20170621

Methods: 

Experimental design:

The Monsoon Rainfall Manipulation Experiment (MRME) contains three ambient precipitation plots and five replicates of the following treatments: 1.) ambient plus a weekly addition of 5 mm rainfall; and 2.) ambient plus a monthly addition of 20 mm rainfall. Rainfall is added during the monsoon season (July-Sept) by an overhead (7 m) system fitted with sprinkler heads that deliver rainfall quality droplets. At the end of the summer, each treatment has received the same total amount of added precipitation delivered in different sized events.

Each plot (9m x 14 m) includes subplots (2m x 2m) that receive 50 kg N ha-1 y-1. Measurements are taken of: 1.) seasonal (July, August, September, and October through June) soil N; 2.) plant species composition and ANPP; 3.) seasonal root and fungal dynamics in mini-rhizotrons; and 4.) soil temperature, moisture, and CO2 fluxes (using in situ solid state CO2 sensors). Also, soil N2O fluxes, predawn and mid-day (10-12 AM) water potential, and mid-day leaf photosynthetic gas exchange and stomatal conductance of black grama are measured prior to and up to 5 days after scheduled precipitation events.

Above-Ground Net Primary Productivity (ANPP) measurements:

Above-ground net primary production data is collected in the spring and fall. 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.

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. It is possible to obtain a total percent cover greater than 100% for a given quadrat because vegetative units for different species often overlap.

Niners and plexidecs are additional tools that can 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

Cover Measurements:

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-The cover of forbs is measured as the perimeter of the densest portion of the plant. If the forb is an annual it is acceptable to include the inflorescence in this measurement. If the forb 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 Measurements:

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 shrub and sub-shrubs-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.

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 should be as follows: npp_mons.mm.dd.yy.abc.xls. File names should be in lowercase.

August 2009 Burn:

On August 4, 2009, a lightning-initiated fire began on the Sevilleta National Wildlife Refuge. The Monsoon site was entirely burned on this date, with all plots subjected to fire of comparable intensity.

Maintenance: 

01/13/2011-Spring and Fall 2010 data was updated, QA/QC'd and uploaded. (JMM) 11/26/2009-Spring 2009 data was updated, QAQC'd and uploaded. Fall season data was not collected due to an unexpected fire at Sevilleta LTER in Aug 2009. (YX) 11/26/2009-Metadata complied for data from 2006 to 2009. (YX) 01/14/2009-Metadata compiled for data from 2006 to 2008. (YX) 12/20/2008-Data was QAQC'd in MySQL. I checked for duplicates, missing quads, and species codes. (YX)

Additional information: 

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; 08/2010-06/2013), 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).Data updated 08/18/15: MOSQ changed to MUSQ3; ARPUP6 changed to ARPU9; SPWR changed to SPPO6.

Tree Mast Production in Pinyon-Juniper-Oak Forests at the Sevilleta National Wildlife Refuge, New Mexico (1997- present)

Abstract: 

The purpose of this study is to monitor the fruit production of three woody tree species that occur on the Sevilleta National Wildlife Refuge (NWR). Two monoecious species, Pinus edulis and Quercus turbinella, are assessed, as is a dioecious species, Juniperus monosperma. In August, fruit production is estimated for the three species at five sites within the Sevilleta NWR. For each of the species different protocols are used for estimating fruit production: P. edulis estimates are made using the number of cones per mature tree, Q. turbinellla estimates utilize the number of acorns per 0.1m2 of canopy surface area, and J. monosperma estimates use the number of berries per twig on female trees. In addition, the age and/or size of each individual tree was assessed at the beginning of the study. For P. edulis and J. monosperma, distinctions continue to be made between young, medium, old, and very old trees; for Q. turbinella, canopy surface area is estimated.

Core Areas: 

Data set ID: 

204

Keywords: 

Purpose: 

This study is designed to monitor the fruit production of three woody tree species that occur on the Sevilleta National Wildlife Refuge (NWR).

Data sources: 

sev204_mastproductionall_20150114.txt

Methods: 

Site information:

At each study site, four 1 ha plots were established. Each plot was divided into four subplots.

Spatial structure of juniper, pinon pine and oak populations:

All trees and shrubs within the 1 ha plots were tagged and mapped using either GPS cordinates or compass headings. Height, canopy diameter (in both north-south and west-east directions) and diameter-at-breast-height (DBH) of trunk were measured for all woody plants, including those that died during the drought of the 1950's. Juniper and pinon trees were subdivided into four age/size groups based upon mean canopy radius for juniper and DBH for pinon. For oak trees, the canopy surface area of all individual trees was measured.

Measuring mast production:

Berry, cone, and acorn production is measured in August when fruits are ripening. Three different methods were developed to estimate annual production.

For juniper, the percent of twigs with berries and the quantity of berries per twig are determined every year for all trees in each plot. The average twig has a length of 45 cm and trunk diameter of 12 mm. Estimates of berry production are made separately for the upper and lower halves of the crown, and for the northwestern, northeastern, and southern sectors and the mean number of berries per twig calculated.

To determine berry production per tree and per hectare, the average number of twigs on trees of different size groups is estimated. Samples of 500-800 berries from a plot are taken randomly each year to determine the percentage of developed and underdeveloped berries, as well as berries with the pericarp damaged by insects.

The absolute number of third-year, ripened, green cones is estimated on all trees within the 1 hectare plots. Young brown cones of the second year are also counted to predict the yield of cones the following year. Cones are counted with binoculars.  The unit of pinon mast production is cones/seeds per mature tree.

To estimate cone predation in the spring, the number of damaged female stems and the mortality of conelets are estimated. Then, in August of the following year, samples of 100 green ripened cones are collected randomly on 30-40 trees at each of three pinon sites, and the ratio of filled seeds to empty seeds, as well as the percentage of cones damaged by predatory insects, estimated.

Several hundred ripened cones and filled ripen seeds were initially measured to determine their average weight. The average dry weight of a ripened cone consisting of filled seeds was 3.5 g. The weight of a cone with no seeds was 2.1 g, representing 62% of total weight. The average number of filled seeds in a cone was six and the average dry weight of a filled seed 0.22 g, consisting of a seed shell of 0.13 g (59% of seed weight) and a seed core of 0.09 g (41% of seed weight).

A different method is used to estimate acorn production. First, the canopy surface area of each oak tree is determined. The number of acorns is counted separately for well-developed, undeveloped, and those damaged by Curculionidae beetle larvae within a 31 cm x 32 cm frame projected onto the crown surface of each oak tree in 3-5 repetitions. Acorns are subdivided into three size groups, small, medium, and large. Medium acorns are most common. To determine the weight of acorns, 100 acorns of each small, medium and large size were collected from 50 different trees.

A comparison of production of the three woody species was done on the basis of fruit biomass per unit of measure: well-developed, undamaged berries per twig for juniper, filled seeds per mature tree for pinon pine, and well-developed, undamaged acorns per 0.1 m2 of canopy surface for oak. Additionally, biomass of berries, pinon seeds and acorns per hectare was estimated in order to compare production at the five sites and quantify annual fluctuations.

Site abbreviations are as follows:

CM=Cerro Montosa

GD=Goat Draw

FS=Field Station

MF=McKenzie Flats

222=222/Red Tank

WM=West Mesa

Plot:

Plot refers to the 1 ha area and associated subplots where data is collected. Values range from I1-I4, II1-II4, III1-III4, IV1-IV4.

Maintenance: 

Data were compiled into a single file for all years. In addition, a year column was added. Cells that had a period (.) or were blank were changed to NA. Abbreviations were given for sites and Kartez codes assigned for juniper, pine, and oak. File was saved as CSV. TK. 6 February 2009. Data were qa/qc'd for obivous errors and metadata was updated. Added West Mesa site. 11 January 2010. tlk. Changed the order of variables so that "year" is first and "site" is second. The order of the other variables has not been changed, only shifted. Added information to West Mesa site. Added Biome Transition Area site, replacing previous name, McKenzie Flats. 8 March 2010, tlk. Kristin updated Roman's personal information. 12 March 2010, tlk.

Quality Assurance: 

 Datasheets were visually assessed for any errors.

Additional information: 

Data collection began in 1997 and is ongoing.

Nitrogen Fertilization Experiment (NFert): Net Primary Production Quadrat Data at the Sevilleta National Wildlife Refuge, New Mexico (2004-present)

Abstract: 

This dataset is part of a long-term study at the Sevilleta LTER, begun in spring 2004, which examines how fertilization affects above-ground biomass production (ANPP) in a mixed desert-grassland. 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 foliage, over time and incorporates 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. 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 SEV186, "Nitrogen Fertilization Experiment (NFert): Seasonal Biomass and Seasonal and Annual NPP Data."

Core Areas: 

Data set ID: 

155

Additional Project roles: 

442
443
444
445

Keywords: 

Data sources: 

sev155_nppfertquadrat_20170621

Methods: 

Study Design:

Twenty 10m X 5m plots were established in December 2005. Ten plots are fertilized; ten are unfertilized. Fertilizer is applied twice yearly (spring and fall) as granular NH4NO3 at the rate of 100 kg N ha-1 yr-1.  Within each plot are four sampled quadrats (n=80).  Quadrats are adjacent and numbered from south (1) to north (4) starting at the southeastern corner of each plot.

Collecting the Data:

Net primary production data is collected twice each year: spring and fall. 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.

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. It is possible to obtain a total percent cover greater than 100% for a given quadrat because vegetative units for different species often overlap.

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

Cover Measurements:

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-The cover of forbs is measured as the perimeter of the densest portion of the plant. If the forb is an annual it is acceptable to include the inflorescence in this measurement. If the forb 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 Measurements:

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 shrub and sub-shrubs-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.

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 should be as follows: npp_fert.mm.dd.yy.abc.xls. File names should be in lowercase.

Maintenance: 

1/12/2011 - Quad data for spring and fall 2010 QA/QC'd and put in Navicat. Metadata updated and compiled for 2010. (JM) 11/28/2009 - Quad data QA/QC'd and put in Navicat. Metadata updated and compiled for 2006 -2009. (YX) 1/06/09 - Metadata updated and compiled for 2006, 2007, 2008. (YX) 01/06/09 - As of 2007, winter measurement is no longer being taken. (YX) 12/10/2008 - NPP data from 2004-2008 was QAQC'd in MySQL. I checked for duplicates and missing quads. (YX) 1/12/2006 - Meta data compiled for 2005.  5/16/2005 - Season 3, Plot 11 data didn't distinguish between quads 3 and 4. Original data were checked and this error was corrected. -KLV

Additional information: 

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; 08/2010-06/2013), 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); 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).Data updated 08/18/15: ARPUP6 changed to ARPU9; MOSQ changed to MUSQ3; SPWR changed to SPPO6.

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