vegetation dynamics

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).

Response of Vegetation and Microbial Communities to Monsoon Precipitation Manipulation in a Mixed Blue and Black Grama Grassland at the Sevilleta National Wildlife Refuge, New Mexico

Abstract: 

The purpose of this project is to test the hypothesis that the smallest 50% of precipitation events during the monsoon season affect microbial functioning and grassland productivity in mixed grasslands of B.eriopoda and B. gracilis at the SNWR. At the SNWR, the summer monsoon season accounts for 60% of total annual precipitation and drives the majority of vegetation productivity during the year; the largest 25% of precipitation events account for the majority of this precipitation. I predict that important ecological variables such as nutrient and soil moisture availability are disproportionately influenced by smaller events. The proposed project will help tease apart the importance of precipitation event classes on nutrient availability and grassland aboveground net primary production (ANPP). This research will also provide a basis for understanding how increased aridity in the U.S. southwest due to increasing global surface temperature and altered precipitation could affect grassland communities at the SNWR.

Additional Project roles: 

34
35

Data set ID: 

286

Core Areas: 

Keywords: 

Methods: 

We will implement 10 open plots (control) and 10 precipitation exclosure plots(treatment; 20 total plots) at a mixed blue and black grama grassland site at the SNWR. In this experiment, treatment plots will only receive the largest 50% of precipitation events. This will maintain statistically similar total precipitation between control and treatment plots because the smallest 50% of events have an insignificant effect on total seasonal precipitation. How these small events are linked to microbial activity and vegetation productivity is still very much unknown. I predict that soil microbial activity and nutrient availability will differ between control and treatment plots and will result in differing vegetation ANPP between them. These effects may become more distinct as time progresses, which is the reason for conducting this research for a series of monsoon seasons.

Existing precipitation exclosures (2.45 m x 2.45 m) will be employed at the mixed grassland site. We will implement 20 total plots (10 control, 10 treatment; approx. 500 m2 total area). Temporary site infrastructure will include 10 precipitation exclosures, a water tank (1100 gal.) and soil moisture probes. This infrastructure currently exists at the mixed grassland site and will be adopted from Michell Thomey's project entitled, "Soil moisture extremes and soil water dynamics across a semiarid grassland ecotone."

Precipitation is the only independent variable in this experiment. Using precipitation exclosures, I will remove all ambient precipitation from treatment plots from DOY 182-273. Ambient daily precipitation thatexceeds the estimated 50% threshold will be delivered to the plots within 24 hours of an event. Delivered precipitation will be adjusted for atmospheric demand differences. 

Dependent variables in this experiment are vegetation ANPP, soil nitrogen content, soil enzymatic activityand soil moisture content. Vegetation biomass will be collected from the sites on DOY 181 and 274. Soil enzymatic activity will be determined approximately 4 times per monsoon season using plot soil samples. Soil nitrogen content will be measured under vegetation using nitrogen probes. Volumetric soil moisture content [m3 m-3] will be measured continuously using soil moisture probes (30 cm depth). 

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.

Discontinued Vegetation Line-Intercept Transects in Transition Zones at the Sevilleta National Wildlife Refuge, New Mexico (1989-1998)

Abstract: 

The line-intercept transects included in this data set have been discontinued. These transects were installed to evaluate temporal and spatial dynamics in vegetation transition zones (e.g.black grama grassland/creosote shrubland) at one centimeter resolution. Each study site originally contained four 400 m transects, representing total coverage of 1 sq km. The transects were placed along a roughly north/south azimuth. The northwestern and southwestern transects were 100 meters from the western edge of the 1 sq km study area and the northeastern and southeastern transects were 100 m from the eastern edge, providing 800 meters between the eastern and western transects. The northeastern and northwestern transects began to the north and, after an interval of 200 meters, the southeastern and northeastern transects began, terminating at the southern edge of the study area.

Ongoing line-intercept transect data for transect 1, which continues to be sampled at both Deep Well and Five Points, can be found in SEV004.

Core Areas: 

Data set ID: 

200

Additional Project roles: 

191

Keywords: 

Data sources: 

sev200_disconlineint_20160303.csv

Methods: 

Measuring the Transects: A 100 m tape was attached to permanent pieces of rebar at each of the four segments of a 400 m transect. The tape was stretched as tightly as possible to get the straightest line. Windy days were avoided as this became impossible.

Crew members worked independently, each sampling a 100 m segment simultaneously. Microcassette recorders and standard microcassettes were used to record data. At each 100m segment, the following sequence was followed:

Each species or substrate encountered along a transect was recorded at the centimeter level. The distance at which a species or substrate first crossed the tape was recorded.  Starting points only were recorded as the ending point of a species or substrate was the starting point of the next. It was also noted whether vegetation was fully alive, fully dead or a mix of both.

Maintenance: 

Changes to the data: This dataset (SEV200) includes all discontinued line-intercept transect data files. In particular, data is included from Bronco Well, Valle de la Jornada, Rio Salado and Sepultura Canyon, as well as transects 2-4 from Deep Well and Five Points.  Transect 1, season 2 data from Deep Well and Five Points in 1994 is also included (1994 was the only year that three seasons od data were collected). Otherwise, SEV004 contains transect 1 data from Deep Well and Five Points.

The data in this file has not been rigorously QA/QCed. Old metadata and individual year data can be found in: /export/db/local/htdocs/data/archive/plant/transect/data_oldformat. This data will not be available online. See the Sevilleta data manager for data and metadata in this old format.

Additional information: 

Principle investigator:
1989-1998: Milne, Bruce; Gosz, Jim

Data Manager:
1989-1992: Taugher, Kimberly
1993: Maddux, Troy; Taugher, Kimberly
1994: Maddux, Troy; Taugher, Kimberly; Chavez, Melissa
1995: Geer, Susan; Taugher, Kimberly
1996-1998: Taugher, Kimberly

Field Crew
1989: Banar, Alethea; Keller, David; Loftin, Sam; Maddux, Troy; Wolterstorff, Susan
1990: Franklin, Jennifer; Loftin, Sam; Maddux, Troy; Murillo, Michelle; Shortess, Amy;
Viers, Joran
1991: Maddux, Troy; Loftin, Sam; Viers, Joran; McGee, Kathleen; Prichard, Susan
1992: Maddux, Troy; Chavez, Melissa; Valdez, Monica; Bradley, Mike; Knight, Julie;
Collier, Anthony; Persaud, Amanda; Ortiz, Ivan
1993: Oriz, Ivan; Swanick, Raine; Taylor, Rob; Wagner, Natalie
1994: Chavez, Melissa; Bocock, Jonathan; Altenbach, Marilyn; Yanoff, Steven; East,
Micheal; Muckenhoupt, Jim; Budkovich, Pamela; Grant, Tom
1995: Geer, Susan; Smith, Richard; Carpenter, Claire; Parker, Kelli; Giese, Kristy;
Belden, Lisa; Weiss, Linda
1996: Taugher, Kimberly; Belden, Lisa; Payne, Jennifer; Monteith, Nancy; Newingham,
Beth Oldehoeft, Kim; Sexton, Jason
1997: Taugher, Kimberly; Campbell, Mariel; Conn, Rachel; Kuehner, John; Helm, Amy;
Kendall, John
1998: Kuehner, John; Frasier, Jason; Korbe, Nicole; Kroll, AJ; Hayes, Betty; Hersch, Erika

More information about when the data were collected:

Spring 1989 Summer 1989
dw 5/17/89-6/4/89 8/4/89-8/7/89
fp 6/5/89-6/12/89 8/8/89-8/9/89
sp 5/22/89-5/30/89 8/1/89-8/3/89
vj 6/13/89-6/20/89 8/10/89-8/11/89

Spring 1990 Summer 1990
All 5/23/90-6/14/90 All 8/6/90-9/5/90

Spring 1991 Summer 1991
All 5/22/91-7/12/91 All 7/22/91-8/15/91

Spring 1992 Summer 1992
All 6/3/92-6/18/92 7/28/92-8/6/92

Spring 1993 Summer 1993
dw 5/27/93-5/31/93 7/14/93-7/20/93
fp 6/4/93-6/10/93 7/22/93-7/27/93
vj 6/14/93-6/17/93 8/3/93-8/4/93
rs 6/17/93-7/9/93 8/4/93-8/10/93
bw 6/21/93-7/21/93 8/12/93-8/17/93
sp 7/6/93-7/8/93 not measured

Spring 1994 Summer1994 Fall 1994
dw 6/6/94 7/26/94 9/27/94-9/28/94
fp 6/8/94-6/9/94 8/2/94 9/29/94-10/3/94
vj 6/20/94 8/1/94-8/2/94 10/5/94
rs 5/31/94-6/3/94 7/25/94 10/6/94
bw 6/15/94-6/16/94 8/4/94 10/10/94-10/11/94
sp 6/23/94-6/27/94 8/9/94 10/13/94

Spring 1995 Fall 1995
dw 5/25/95 10/2/95
fp 5/30/95 9/26/95
vj 6/5/95 9/27/95
rs 5/23/95 9/25/95
bw 5/31/95 10/3/95
sp 6/6/95 10/4/95

Spring 1996 Fall 1996
dw 5/23/96 9/17/96
fp 5/27/96 9/19/96
vj 6/5/96 10/8/96
rs 5/29/96 9/25/96
bw 6/13/96 10/2/96
sp 6/3/96 9/30/96

Spring 1997 Fall 1997
dw 6/10/97 10/2/97
fp 6/11/97 10/8/97
vj 6/5/97 10/14/97
rs 6/12/97 10/16/97
bw 6/4/97 10/15/97
sp 7/15/97 10/22/97

Spring 1998 Fall 1998
dw 6/8/98 9/15/98
fp 6/1/98 9/17/98
vj 6/15/98 9/16/98
rs 7/8/98 9/29/98
bw 6/11/98 10/6/98
sp 6/30/98 10/8/98

Snakeweed (Gutierrezia sarothrae) Habitat Vegetation Transect Data from the Sevilleta National Wildlife Refuge, New Mexico (1996)

Abstract: 

In 1984, a research project was initiated on a relatively small disturbance patch just south of Deep Well. This disturbance was thought to be the result of an old praire dog town, probably dating back to when a nearby ranch was active, and a lot of old mammal mounds remained in the disturbed area. One of the things that made the disturbance patch particularily noticeable was the lush growth of snakeweed (Gutierrezia sarothrae) within the patch. This prompted the designation of the disturbance patch as the "snakeweed patch" or "gutierrezia patch". In addition, there was an obvious increase in bare ground and a shift in vegetation composition across the patch boundary. The dominant vegetation was not consistent around the boundary, with a marked dominance of black grama on the west side of the plot and a blue/black grama mix on the other three sides. To obtain information on the cause and/or effect of this disturbance, a survey of the soil and vegetation was performed.

In 1996, standard 100 m transects were set up parallel to the original vegetation transects and measured in a manner similar to SEV004 (Plant Line-Intercept Transects).

Data set ID: 

151

Core Areas: 

Additional Project roles: 

187

Keywords: 

Methods: 

Transect set-up - A 100 m measuring tape was affixed to the 0 meter rebar stake (north) and run to the 100 meter (south) end of each of four transects. The tape was stretched as tight as possible to get the straightest line. Windy days were avoided to prevent the tape from billowing.

Recording data - Four crew members worked independently, each doing a 100 m segment simultaneously. Microcassette recorders and standard microcassettes were used to record data. At each 100 m segment, the following sequence was followed: Each species/substrate encountered along the line and the distance at which that species/substrate crossed the tape was recorded. Starting location only was recorded as the ending point was the starting point of the next species/substrate.

Coordinates (NAD27): 

End of

Transect Transect Latitude Longitude

North 0 34 21' 1.2" 106 41' 8.3"W

100 34 20' 57.9"N 106 41' 8.6"W

East 0 34 20' 47.0"N 106 41' 1.6"W

100 34 20' 46.5"N 106 41' 5.4"W

West 0 34 20' 53.7"N 106 41' 16.3"W

100 34 20' 53.7"N 106 41' 12.4"W

GCA 0 34 20' 49.1"N 106 41' 9.2"W

100 34 20' 45.6"N 106 41' 9.2"W


Data sources: 

sev151_snakeweedtransects_01122010

Additional information: 

1996 REU's with assistance from the 1996 Field Crew.

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.

Biannnual Creosote Branch Demography Study at the Sevilleta National Wildlife Refuge, New Mexico (1989-1993)

Abstract: 

This project was designed to investigate the response of plant growth and reproduction to short- and long-term variation in biotic and abiotic environmental variables. Several perennial taxa, including tree (Juniperus monsperma and Pinus edulis), shrub (Larrea tridentata) and bunch grasses (Oryzopsis hymenoides (now Achnaterum hymenoides) and Sporobolus contractus) species, were monitored at 1-3 sites differing in elevation and topography as well as edaphic variables and annual precipitation. The sites represented optimal or marginal/transitional zones for particular species. Demographic measurements were made biannually, after the 'wet' (fall) and 'dry' (spring) seasons. For tree and shrub species, estimates of growth and reproduction were based on branch demography, with ten branch tips from 10-20 individuals per species per site repeatedly measured from 1989-1993.  For J. monsperma, P. edulis and L. tridentata, vegetative growth (i.e., branch growth) as well as reproduction were monitored. Additional measurements included needle length for P. edulis and leaf production, leaf size and branchlet production for L. tridentata. For grasses, basal diameter, leaf length and reproduction were monitored for 100 individuals per species per site.

This project, SEV026, contains only data on creosote branch demography.  Data on other variables and species is contained in SEV006, SEV024, SEV025, SEV027, and SEV028.

Core Areas: 

Data set ID: 

26

Additional Project roles: 

180
181
182
183
184
185
186

Keywords: 

Data sources: 

sev026_creosotedemography_20160218.txt

Methods: 

Plant Selection - One hundred Larrea tridentata individuals were selected and numbered. Twenty individuals were randomly selected for measurement.

Branch Selection - Ten branches were numbered consecutively around each shrub to cover all exposures.

Tag Placement - Tags were placed about five centimeters from the tip of the branch at a node where the branch forked. Branches were also marked at that point with a paint pen so each tag could be tied loosely, thereby not restricting vascular flow.

If a tagged branch died the tag was placed on another branch using the same number with a ".1" suffix. For example if branch 4 was found dead, another branch was marked 4.1. If, in subsequent seasons, 4.1 was found dead another branch was marked 4.2.  

Plant Measurement:

1. Branch Length - This is the length from tag to tip of branch. If a tag was loose it was moved back toward the plant until stopped  by a node where two branches diverged. A paint mark indicated this location. If a paint mark was elsewhere then measurement was done from the paint mark and it was noted on the data sheet that the paint mark was not at a branching point.

2. Leaf - This is the number of leaves between tag (or tag mark) and tip of branch. Creosote has compound leaves so two leaflets usually comprised one leaf. If one leaflet was missing the leaf was still counted as one. If leaf status was uncertain, the petiole or point of attachment to the stem was used as verification.

3. Leaf Length1 - This is the length of one leaf on a tagged branch. This measurement was considered to be the length of the blade of one leaflet NOT including the petiole.

4. Leaf Length2 - This is the same measurement as Leaf Length1 performed on a different leaf.

5. Bud - The number of buds between the tag (or tag mark) and the tip of the branch.

6. Flower - The number of flowers between the tag (or tag mark) and the tip of the branch.

7. Fruit - The number of fruits between the tag (or tag mark) and the tip of the branch.

8. Branchlet - The number of branchlets between the tag (or tag mark) and the tip of the branch.

Maintenance: 

I. Condensed log of activity of plant demography data:a. Individual documentations initiatiated 1989; Troy Madduxb. File (combined documentations) 31 August 1990; Troy Madduxc. Abstract (Written by Diane Marshall and Charles Wisdom) put in documentation 31 August 1990; Troy Madduxd. Documentation expanded 2 September 1990; Troy Madduxe. Concatenation of individual documentations iniatiated September 1990, completed 17 December 1990; Michelle Murillof. File expanded into rdb file 17 December 1990; Michelle Murillog. Rdb file checked, and errors eliminated 18 December 1990; Michelle Murilloh. KEYWORDS added 19 December 1990; James Brunti. Random error checking completed 20 December 1990; Michelle Murilloj. File complete and archived 21 December 1990; Michelle Murillo & Greg Shore. Documentation changed to reflect changes in datafile structure; 1 March 91 T. Maddux.II. Detailed log of alterations/modifications of plant demography data: This portion of the log contains details of all alterations and modifications applied to this file by Michelle Murillo. The file demography.dat was initiated in September 1990 by concatenating individual files into the demography.dat file. A generic header was devised to apply to all individual files. The header reads as such:date season site species station plant# branch# #1 #2 #3 #4 #5 #6 #7 #8and the detailed description of the numbers 1-8 are listed in the documentation section of this file. The individual files were then modified to follow this header, which entailed rearranging of columns (generally the season, site, species, station, plant#, and branch#) and the addition of the date column. As the columns numbered 1-8 did not pertain to all individual files, non-applicables (na) were inserted where necessary. Other alterations included:1. juniper 1989: Sepultura Canyon; addition of na's to presence/absence of male or female cones, depending on sex of tree, i.e. if tree was female then na's were inserted in the male column Goat Draw; same as Sepultura Canyon2. juniper 1990: (Sepultura Canyon site has been discontinued) Goat Draw (season 1); orginal file contained x,y and --'s; which were converted to 0 (absence) and 1 (presence) and appropriate na's were inserted, depending on sex of tree Goat Draw (season 2); orginal file contained +'s for presence of cones; which were converted to 1 (presence) and appropriate na's were inserted depending on sex of tree.NOTE: In 1989 width of branch was measured, and in 1990 this measurement was no longer taken. (The orginal data sheets for 1989-2 are unavailable at the time of archiving, assumption is that this measurement applies to season 2 also). In 1990 the length of branchlet was measured which was not measured in 1989. (See documentation).NOTE: In 1989 (both seasons) the variable, number of branchlets, was not included. In 1990 the variable was added, but measurements of this variable was sporadic, occuring only in a few plants.3. grasses 1989/1990: All sites: addition of na's to branch#Error checking was done as follows: Two files, grasses 1990-season 1, and creosote 1990-season 1, had not been entered at the time of concatenation of individual files, and were therefore entered by Michelle Murillo. These two files were errored checked by Michelle Murillo by visual checking of original data sheets with the files on 18 December 1990. On 17 December 1990, the expand program was applied to the demography.dat file and placed into the demography.rdb file. The rdb file was then checked for various errors, and the elimination of these errors were completed on 18 December 1990. On 19-20 December 1990, random error checking was conducted by using 'Tables for Statistical Data-Analysis'. One hundred and fifty entries were checked and approximiately 45 percent of the numbers were from 1989-season 2, and because the data sheets were unavailable, the entries were not error checked. On 23 December 1990, visual checking with the original data sheets was conducted for an overall check.File initiated June 1991: MLM season 1 entered: MLM season 2 entered: KPM Black Butte, season 2 entered and error checked, 7 Jan 1992: MLM data entry complete 25 October 1991: KPM data error checking completed 8 November 1991: KPM Documentation updated (New people and times added) on 29 Jan 1992 and inserted into data file by Troy Maddux. 1992 log * Put the 1992 data in the data base on 22 Oct 1992 Troy Maddux.THE FOLLOWING IS THE LOG FOR THE SPRING 1992 DEMOGRAPHY DATA: File initiated by Troy Maddux 24 Aug 1992. Goat Draw pied information entered by Michael Bradley and sent to Troy Maddux Wed Aug 19 15:31:03 1992 and these data added to this file by T. Maddux on 15 Oct 1992. Black butte data added to this file 15 Oct 1992. Many SPCO4 plants in plots 2 and 3 of Five Points had no data for the inflorescence # so this was added (it was 0) on 15 Oct 1992 by Troy Maddux. Removed extra '0' from rs spco #531-534 - 16 Oct 1992, T.M. Pulled doc from 1991 demography data to change for 1992 data 16 Oct 1992; T.M. Who and When data were collected was added 20 Oct 1992; T.M.THE FOLLOWING IS THE LOG FOR THE FALL 1992 DEMOGRAPHY DATA: File initiated 16 Sep 1992 by Tiffany Cotlar. Data file from Tiffany Cotlar and a data file from Robin Abell combined; also blank lines removed from both files, this was done by Troy Maddux on 20 Oct 1992.File initiated 16 Sep 1992 by Robin Abell PIED #'s 9,13,23,15,17,36,41,42 by Robin Abell. 16 Sep 1992 JUMO #'s 26,23,24,28,49,5,8,17,13,22,36,41,47,4,15,27,32,46,42 by Robin Abell 16 Sep 1992. LATR2 #'s (Five Points) 2,3,5,26 by Robin Abell 23 Sep 1992. SPCO4 #'s (Station B) 61,92,93,94,95,99,101,103,104,105,108,109 * 109.1,110,110.1,111,112,112.1,122,125,126,127,130,148,149,402 by Robin Abell 23 Sep 1992. LATR2 #'s (Five Points) 90,92,96 by Robin Abell 24 Sep 1992 *LATR2 #'s (Rio Salado) 1,14,17 by Robin Abell 1 Oct 1992 changed typo: juno to jumo; 20 Oct 1992, T.M. added additional field to grass data to make the field # correct 20 Oct 1992, TM. File submitted for archival 22 OCT 1992 - Troy Maddux.File initiated by Troy Maddux 22 Apr 1993 combining data entered by Ursula Bonhage, Roger Stupf, Christian Heierli, Marilyn Altenbach, and Eric Scherff.File initiated by M. Altenbach 22 April 93 , fp LATR2 2, 3, & 5. Data altered to archive format by Troy Maddux - 16 Nov 1993. Data for larrea tridentata (numbers 13, 20, 23, 26, 28, 30, 51, 75, 76, 79, 82, 89, 90, 92, 96) for Five Points.Data entered 29 apr 93 by ubonhage, rstupf data taken by altenbach, bonhage, hierli, scherff, stupf on 20 apr 93 'na' for station. Data for LATR2 numbers 97 and 100 entered by Troy Maddux and error-checked by Troy and Doug Moore on 16 Nov 1993. Data for Rio Salado demography, all 20 LATR2, data collected from 4/22-4/29. From altenbac Wed May 5 12:01:08 1993; initiated by M. Altenbach 3 May 93. Documentation taken from 91-92 archive data set and modified for this data set. 18 Oct 1993, by Troy Maddux. Filled in "Who" and "When" sections from the data sheets - Troy Maddux - 16 Nov 1993. Data entered for Oryzopsis adult measurements--Rio Salado 23 April & 4 May 1993 maps not edited; From escherff Wed May 5 12:27:02 1993 File initiated by E. Scherff on 3 May 1993.1993 FALL DATA File appended by Eric Scherff and Cynthia Gregoire on 22 September 1993. Changed "nd" representing "no data" to "na" to be consistent with other data bases. - Troy Maddux - 8 Nov 1993. File for Rio Salado information created by Cynthia Gregoire & Eric Scherff on 24 September 1993. Data collected by Marilyn Altenbach, Eric Scherff and Cynthia Gregoire on 21 September 1993 and 22 September 1993. File for Five Points Creosote created by Eric Scherff and Cynthia Gregoire on 27 September 1993. Data collected by M. Altenbach, E. Scherff, C. Gregoire, and T. Maddux on 15 September 1993, 16 September 1993, and 20 September 1993. File Rio Salado creosote data created by Eric Scherff and Cynthia Gregoire on September 27, 1993. Data collected by Marilyn Altenbach, Eric Scherff and Cynthia Gregoire on September 22, 23 & 24 1993. Spring and Fall data put together in Archive File format 17 Nov 1993. by Troy Maddux - also changed nd's and dashes to na's.14 March 1994. Separated the big demography-89-90 file into four parts; grass, pinyon, creosote, and juniper. Rupal Shah went through and separated the file and edited the documentation.28 March 1994. Rupal Shah edited this file and changed the 1989 fp plant # 51 from season 1 to 2. Rupal Shah kept on changing and working on it until 5-4-94.11-april, 1994. The data sheets for plant numbers 96, 97, 100 for season 1, fp, 1991 and plant numbers 2, 3, and 5 for season 2, fp, 1991 are missing. RS. Rupal Shah changed and worked on it until 5-4-94. Changed a couple of uppercase "na"s to lowercase.3/18/98 - Changed species codes to Kartesz codes. K. Taugher - Updated metadata section on plant codes to reflect this new coding scheme. K. Taugher - Added a final line to the dataset of: "{END OF DATA}" K.Taugher - Realigned columns to right justification. K. Taugher.9/23/98 - Added reference for Kartesz. K. Taugher doc.

Additional information: 

The data for the first census (May 1989) were collected by Ann Evans (Asst. Professor/UNM), Troy Maddux (Head Plant Tech/LTER), Sam Loftin (Graduate Student/UNM), Marikay Ramsey (Head Animal Tech/LTER), Joran Viers (Plant Tech/LTER), Michelle Murillo (Plant Tech/LTER), Jennifer Franklin (Plant Tech/LTER), Amy Shortess (Plant Tech/LTER).

The data for the second census (September 1989) were collected by Troy Maddux (Head Plant Tech/LTER), Amy Shortess (Plant Tech/LTER), David Keller (Plant Tech/LTER).

1991: The data for the first census (May) were collected by Roger Mongold (Plant Technician), Brad Swanson (Plant Technician), Joran Viers (Plant Technician), Kathleen McGee (Plant Technician), Sam Loftin (Graduate Student Technician), and Troy Maddux (Head Plant Technician).

1991: The data for the second census (May) were collected by Jim Stanton (Plant Technician), Susan Prichard (Plant Technician), and Troy Maddux (Head Plant Technician).

1992: The data for the first census (Apr-Jun) were collected by Troy Maddux (Head Plant Technician) and the following plant technicians: Marilyn Altenbach, Michael Bradley, Melissa Chavez, Anthony Collier, Julie Knight, Ivan Ortiz, Amanda Persaud, Monica Valdez.

1992: The data for the second census (Aug-Oct) were collected by Troy Maddux (Head Plant Technician), Robin Abell (Plant Technician), and Tiffany Cotlar (Plant Technician).

1993: SPRING CENSUS - Roger Stupf (Volunteer from Switzerland), Ursula Bonhage (Volunteer from Switzerland), Christian Heierli (Volunteer from Switzerland), Marilyn Altenbach (Field Crew Chief), Eric Scherff (Field Tech), Troy Maddux (Vegetation Studies Program Manager).

1993: FALL CENSUS - Cynthia Gregoire (Volunteer from Vermont), Marilyn Altenbach (Field Crew Chief), Eric Scherff (Field Tech).

Snakeweed (Gutierrezia sarothrae) Habitat Soils Data from the Sevilleta National Wildlife Refuge, New Mexico (1984)

Abstract: 

In 1984, a research project was initiated on a relatively small disturbance patch just south of Deep Well. This disturbance was thought to be the result of an old praire dog town, probably dating back to when a nearby ranch was active, and a lot of old mammal mounds remained in the disturbed area. One of the things that made the disturbance patch particularily noticeable was the lush growth of snakeweed (Gutierrezia sarothrae) within the patch. This prompted the designation of the disturbance patch as the "snakeweed patch" or "Gutierrezia patch." In addition, there was an obvious increase in bare ground and a shift in vegetation composition across the patch boundary. The dominant vegetation was not consistent around the boundary, with a marked dominance of black grama on the west side of the plot and a blue/black grama mix on the other three sides. To obtain information on the cause and/or effect of this disturbance, a survey of the soil and vegetation was performed.

Core Areas: 

Data set ID: 

150

Additional Project roles: 

103
104
105

Keywords: 

Data sources: 

sev150_snakeweedsoil_03302009

Methods: 

Sample collection - The soil samples were collected using a hammer-driven soil corer. The barrel of the corer was fitted with a plastic sleeve that allowed extraction of the soil core generally intact. The  soil corer was driven to a depth of 50 cm and soils split ito 10 cm fractions. This data set contains data for only the top 30 cm.

Samples were taken along six 100 m transects. Four of these transects crossed the patch boundary on the four cardinal points. On these four transects the 0m sample was taken starting 50 m outside the boundary, the 50 m sample was taken at the patch boundary and the 100 m sample was taken 50 m into the patch. The other two transects formed a cross near the center of the patch.

Twenty-one cores were collected along each transect, with increased sampling intensity near the boundary. However, this data set contains data from only the 10 m intervals for a total of 11 samples.

Sample processing - Soil samples were kept in a refrigerator prior to analysis. Each sample was weighed and samples were well-mixed before analysis. Samples were sieved through 2mm screens to remove pebbles and roots. A sample of 25 g was added to a preweighed soil can. Samples were dried for 24 hours at 105 degrees C then cooled and then reweighed. This dry/wet moisture correction was used to calibrate weights for other samples. A 1 g sample was taken from the oven-dried samples and ashed at 500 degrees C for 2 hours and re-weighed after cooling. This provided a measure of organic content. A 12 g sample was weighed into a 125 ml plastic bottle and 100 ml of 2 N KCL added before the bottles were well-shaken. After standing for 24 hours, the KCL was decanted and the samples analyzed for NO3-N and NH4-N on a Technicon Autoanalyzer. Another 5 g sample was weighed into a centrifuge tube and extracted repeatedly with pH 7 ammonium acetate. These samples were brought up to 250 ml and analyzed for Ca, Mg and K using atomic absorption. Fifty g samples of soil were mixed and texture determined using the hydrometer method. Samples were mixed 2:1 with 0.001N CaCl2 and pH measured. From the oven-dried samples 1 g samples were digested using sulfuric acid using the Kjeldahl method. Samples were then brought up to 250 ml and analyzed on a Technicon Autoanalyzer for total nitrogen and phosphorous.

Coordinates (NAD27): 

End of

Transect Transect Latitude Longitude

North 0 34 21' 1.2" 106 41' 8.3"W

100 34 20' 57.9"N 106 41' 8.6"W

East 0 34 20' 47.0"N 106 41' 1.6"W

100 34 20' 46.5"N 106 41' 5.4"W

West 0 34 20' 53.7"N 106 41' 16.3"W

100 34 20' 53.7"N 106 41' 12.4"W

GCSA 0 34 20' 49.1"N 106 41' 9.2"W

100 34 20' 45.6"N 106 41' 9.2"W

GCSB 0 34 20' 47.1"N 106 41' 8.9"W

100 34 20' 47.4"N 106 41' 5.1"W

Maintenance: 

12/10/00 (DM) File created.2/10/2009. (DM) Metadata was updated and compiled.

Rainfall Manipulation Study Vegetation Data from the Chihuahuan Desert Grassland and Creosote Shrubland at the Sevilleta National Wildlife Refuge, New Mexico (2003-2011)

Abstract: 

The overall goal of the rainfall manipulation project is to understand the coupled ecological and hydrological responses of a grassland, shrubland and a mixed grass-shrub vegetation community to extended periods of increased or decreased rainfall. Rainfall manipulation plots have been established in each of these three vegetation communities in the Five Points area of Sevilleta National Wildlife Refuge. In each vegetation community, three control plots, three drought treatment plots, and three water addition plots have been installed, each approximately 10 x 15 m in size. In each plot, vertical profiles of soil moisture probes have been installed under each cover type (canopy and interspace in grassland and shrubland; grass canopy, shrub canopy and interspace at the ecotone (mixed grass-shrub) site). The probes measure differences in infiltration and soil water content and potential associations with these different cover types. In addition, TDR probes have been installed diagonally in each cover type to integrate the water content of the top 15 cm of soil. Each plot contains 18, 1m2 quads made up of 6, 1m2 quads along each of the 3 transects located across each plot. Each spring and fall, the following parameters are measured in every quad: live plant cover, height, and abundance by species; dead plant cover; soil cover; litter cover; and rock cover. Data collection began in the drought and control plots in the spring of 2002. Data collection began in the water addition plots in the spring of 2004.In the grassland and shrubland communities, all nine currently established plots are located together. The three drought plots were located under a single large roof with a 0.5 m path separating each plot (drought treatments ended in 2006). The control plots and water addition plots are similarly grouped, but without the shelter structure. In the ecotone community, the plots are in three groups; each group is comprised of one drought plot, one water addition plot, and one control plot. Control plots received no experimental treatment, while the sliding roofs over the drought plots were used to divert precipitation, producing a long-term drought. The roofs covering the drought plots were lowered when there was no precipitation so that the amount of sunlight received by the drought plots was minimally affected. Water addition was intended to impose a complementary increase in water supply on the water addition plots. 

Data set ID: 

147

Core Areas: 

Additional Project roles: 

336
337
338
339

Keywords: 

Methods: 

Quadrat measurements 

One meter2 vegetation quadrats are used to measure the cover and abundance of all plants present along each of the three transects across each plot.  These quadrats are also used to measure dead plant foliage, leaf litter, bare soil, and rock covers. One person works on each quad, recording the data into a palm top computer.  Two technicians may work independently along the same transect and alternate quadrats.    

To begin quadrat measurements, first locate the three pairs of rebar along the length (across the slope, perpendicular to the gutter edge) of each plot, which mark the endpoints of each transect. Once the transect has been located, run a string across the plot attaching it to the two transect endpoint rebar stakes to act as a guideline for measurements.  Each transect is measured from the left to the right side of the plot (where left and right are from the perspective of a person standing at the bottom edge of the plot where the gutters are located).  

Beginning at the left side of the transect, place the bottom edge of the quadrat along the guidline of the string with the quad pointing away from the gutter edge. After measuring the quadrat, advance the quadrat along the transect by moving the quadrat to the right so that the bottom left corner is moved to the position formerly occupied by the bottom right corner.  Repeat this process until the entire width of the transect has been measured.  *Note: Beginning in the spring of 2010 only quadrats 2-7 (or meters 2-7) were measured. Before the spring of 2010 there were a variable number of quadrats measured per transect.  If the last quadrat did not lie completely within the boundaries of the plot (within the metal edging), the percentage of the plot that lied within the plot boundary was recorded in the comments column of the data sheet and the vegetation data was recorded in the same manner as for the other quadrats.  If the last quadrat lied completely within the boundaries of the plot, 100%  was recorded in the comments section of the data sheet.  This was to ensure that the entire transect had been measured. 

General vegetation measurements

The cover, height, and abundance (standing biomass) are recorded for each species of plant inside the quadrat.  Vegetation measurements are taken in two layers: a ground level layer that includes all grasses, forbs, sub-shrubs, the bases of Larrea tridentata and bare soil and a “shrub” layer that includes the canopy of Larrea tridentata.  The purpose of this approach is to include Larrea canopies, while allowing the cover values of the ground level layer to sum to approximately 100%.    

The quadrat boundaries are delineated by the 1 m2 PVC-frame placed above the quadrat.   Each PVC-frame is divided into 100 squares with nylon string.  The dimensions of each square are 10cm x 10cm and represent 1 % of the total quadrat area or cover.  The cover and height of all individual plants of a species that fall within the 1m2 quadrat are measured.  Cover is quantified by counting the number of 10cm x 10cm squares intercepted by all individual plants of a particular species, and/or partial cover for individual plants < 1%. 

When reading plant cover it is important to stay centered over the vegetation in the quadrat.  If you are not directly centered over the vegetation, cover measurements can be over or underestimated by your angle of view (parallax).  If the surrounding plants prohibit you from leaning directly over the plants, use a tape measure to delineate a vertical column of intercept.  To do this, simply extend the tape measure vertically from the base of the plant up to the frame grid.  

Vegetation cover measurements

Cover measurements are made by summing the cover values for all individual plants of a given species that fall within an infinite vertical column that is defined by the inside edge of the PVC-frame. This includes vegetation that is rooted outside of the frame but has foliage that extends into the vertical column defined by the PVC-frame.  Again, cover is quantified by counting the number of 10cm x 10cm squares intercepted by each species.  Do not duplicate overlapping canopies, just record the total canopy cover on a horizontal plane when looking down on the quadrat through the grid.

Larger cover values will vary but the smallest cover value recorded should never be below 0.1%.  When dealing with individual plants that are < 1.00%, round the measurements to an increment of 0.1.  Cover values between 1.00 - 5.00% should be rounded to an increment of 0.5 and values > 5.00% are rounded to an increment of 5. 

Cover measurements should be calculated separately for living and dead individuals of each species.  However, because these measurements are made infrequently, vegetation should be considered live if it represents the current year’s growth (green and yellow).  This is particularly important for grasses that may have become senescent during the fall sampling of each year.

Creosote:

Two Larrea tridentata coverage measurements are taken (LATR2 for canopy and LATR2B for the basal cover).  The canopy level layer is estimated using the portion of the canopy that falls within the quadrat.  The canopy edge is defined by a straight gravity line from the canopy to the ground (i.e. imagine a piece of string with a weight on the end being moved around the canopy edge).  A basal cover is taken at the base of the shrub and includes all woody vegetation that stems from the ground.  The purpose of taking two measurements for Larrea is to assess changes in shrub canopy cover without confounding the percent cover estimates of other species obtained using the basal layer. For Larrea seedlings the code LSEED is used and is a separate measurement from the Larrea canopy and basal measurements.

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 tissue is frequently mixed with dead tissue in grass clumps.  Provide two sets of measurements for the dead and live foliage, if possible, especially for perennial grass species.  In the case that both live and dead are difficult to separate, measure all of the foliage as live.  Remember that vegetation should be considered live if it represents the current year’s growth.  In general, recently dead foliage is yellow and long-dead foliage is gray.  

Forbs:

The cover of forbs is the perimeter around the densest portion of the plant. Measure all foliage that was produced during the current season including any recently dead (yellow) foliage.

Cacti and Yucca:

The cover of cacti and yucca is made by estimating a perimeter around the densest portion of the plant and recorded as a single cover.  For cacti that consist of a cluster of pads or jointed stems (i.e., Opuntia phaecantha, Opuntia imbricata), estimate an average perimeter around the series of plant parts and record a single coverage measurement.

Vines:

Vine cover (and some forbs) is often convoluted.  Rather than attempt to estimate cover directly, take a frequency count of 10X10X10cm cubes that the vine is present in.

Seedlings:

As with other vegetation measurements, the smallest cover value for seedlings should never be <0.1.  If the value of seedling cover is less than 0.1, round up to 0.1.  In the comments write “SEEDLING.”    

Height measurements

Height is measured with a tape measure as a whole number in centimeters.  All heights are vertical heights that are defined as a line parallel to the pull of gravity; this is not necessarily perpendicular to the ground if the ground is sloping.  Measure the maximum height of each species identified in the quadrat.  Do not measure the heights of every individual plant for a particular species.

Creosote:

The height of Larrea is only taken only at the canopy level (LATR2). Measure the maximum height from the base of the woody vegetation that stems from the ground to the top of the green foliage.  No height measurement is needed at the basal level (LATR2B).   

Annual grasses and all forbs:

Measure the height from the base of the plant to the tallest part of foliage for that species in the quadrat.  Include the height of the inflorescence, if present.  

Perennial grasses:

Measure the height from the base of the plant to the tallest part of green foliage for that species in the quadrat.  Do not include the inflorescence in the height measurement..    

Plants rooted outside but hanging into the quadrat:

Do not measure the height from the ground. Measure only the height of the portion of the plant that is within the quadrat.  In the comments section of the data sheet, record “Hang Over.” or “HO”.

Abundance measurements

Abundance is recorded as the number of individual plants that comprise the cover measurement.  For some species, individuals are hard to distinguish. If there is bare space between two units, they should be considered separate individuals.  

Creosote:

At the basal level (LATR2B) count the number of Larrea bases present in the quadrat.

Dead plant foliage:

For plants that are dead, but still attached to the soil and standing, just record the cover. Do not measure height or abundance for dead plants. Instead, record “-888” in these spaces on the spreadsheet to signify a value that was intentionally not recorded and enter DEAD in the comments. Cover is quantified by counting the number of 10cm x 10cm squares intercepted by each species. As with live vegetation, plant measurements that are < 1.00% should be rounded to an increment of 0.1.  Cover values between 1.00 - 5.00% should be rounded to an increment of 0.5 and values > 5.00% are rounded to an increment of 5.

Remember, if some of the individuals of a plant species, or if portions of the foliage of an individual plant on the quadrat are dead and some alive, provide two sets of measurements for the dead and living foliage. In the case that both live and dead foliage are intermixed and difficult to separate, as in some bunch grasses and shrubs, just record the foliage as live. Any dead plant foliage that is not still attached to the roots and standing is considered leaf litter.

Non-Vegetation Measurements

Materials other than vegetation that are measured in the drought plots include leaf litter, soil, rocks, and buckets (see below). Other than buckets, which occur in very few plots, values should always be recorded for these materials.  If they are not present in a given quad, put ”-888” for their cover values so that it is clear that these categories were not simply overlooked during data collection.  

Heights and abundances are not recorded for any of these materials. Instead, record “-888” for height and abundance and a numerical value for cover, where applicable (see below). If not recorded in the field, the data manager will do so during the QA/QC process.    

Leaf litter:

Leaf litter includes all detached dead plant material on the soil surface, including woody branches.  Cover is quantified by summing the number of 10cm x 10cm squares intercepted by patches of leaf litter.  Cover values < 5.00% should be rounded to increments of 1 and cover values > 5.00% should be recorded in increments of 5.  If there is no leaf litter in the quadrat, record “LITT” in the “species “ column and record “-888” in the cover, height, and abundance columns.    

Some leaf litter cover has distinctive margins and is easy to define and measure. However, leaf litter may occur in diffuse small patches that are separated by bare soil, and distributed throughout the quadrat. For such diffuse cover, determine the actual cover in one typical 10 by 10 cm square (e.g., 0.3), then count the number of squares with diffuse cover (e.g., 5), and multiply the number of squares by the actual cover for a typical square (e.g., 0.3 X 5 = 1.5, then round to 1.0 or 2.0, or if the value had been greater than 5, round to the nearest increment of 5.0) for the total leaf litter cover. All leaf litter measurements are pooled into one observation, and no height or abundance is measured.  Only measure leaf litter that is in the open, do not attempt to measure within clumps of grass, etc.     

Soil:

Measure the cover of the area occupied by abiotic substrates.  Cover is quantified by summing the number of 10cm x 10cm squares intercepted by abiotic substrates.  As with leaf litter, cover values < 5.00% should be rounded to increments of 1 and cover values > 5.00% should be recorded in increments of 5.  If there is no soil in the quadrat, record “SOIL” in the species column for that quadrat and record a “-888” for the height, cover, and abundance. Again, when soil is present, only the cover is recorded and “-888” should be entered for height and count.  

Rock:   

As a separate entry, estimate the cover of rock (particles >1 cm) occurring within the bare ground.  The rock cover estimate can be viewed as an index of how much of the soil surface is rocky or as a subset of the soil cover measurement.  The rock cover should still be measured as a sum of the number of 10cm x 10cm squares intercepted by rock.  Cover values < 5.00% should be rounded to increments of 1 and cover values > 5.00% should be recorded in increments of 5.  Enter “-888” for the height and count.  If there is no rock cover in the quadrat, record “ROCK” in the species column and enter “-888” for the height, count, and cover.

For Grass and for Creosote sites treatments are: Plots 1-4 Drought; plots 5-6 Control; Plots 7-9 Watered; For Mixed site treatments are: Plots 3,6,9 Drought; Plots 2,4,8 Control; Plots 1,5,7 Watered.

Data sources: 

sev147_droughtveg_11142011

Maintenance: 

File created 3/2/2005. -- Kristin VanderbiltUpdated 12/11/2006 --Karen Wetherill Data appended to file on 7/25/2005 -- KLV Data compiled into one file. Metadata entered in EML access database. TK 6 February 2009 data qa/qc in navicat. Made NONE measurements in the following format Cover 0 Height -888 Count -888. Corrected typos and errors. TLK 10 February 2009

Additional information: 

On Aug 4, 2009, a lightning strike ignited a fire in the area west of the road from Black Butte to Five-Points. The fire started around 3:30 PM on the 4th.  The fire was initially concentrated in the Grassland Drought, SMES, and Monsoon study areas. The next day the fire carried north and east to the Deep Well Meteorological station, Warming, and Nut-Net plot areas. The fire was finally contained by the end of the 5th covering  >7800 ha.

Starting in the spring of 2011, only the mixed shrub site will be measured in the spring and in the fall only the mixed shrub and creosote sites will be measured. Measurements at the drought grassland site was discontinued at this time.

Sevilleta Field Crew Employee History

Megan McClung, April 2013-present, Stephanie Baker, October 2010-Present, John Mulhouse, August 2009-Present, Amaris Swann, August 25, 2008-January 2013, Maya Kapoor, August 9, 2003-January 21, 2005 and April 2010-March 2011, Terri Koontz, February 2000-August 2003 and August 2006-August 2010, Yang Xia, January 31, 2005-April 2009, Karen Wetherill, February 7, 2000-August 2009, Michell Thomey, September 3, 2005-August 2008, Jay McLeod, January 2006-August 2006, Charity Hall, January 31, 2005-January 3, 2006, Tessa Edelen, August 15, 2004-August 15, 2005, Seth Munson, September 9, 2002-June 2004, Caleb Hickman, September 9, 2002-November 15, 2004, Heather Simpson, August 2000-August 2002, Chris Roberts, September 2001-August 2002, Mike Friggens, 1999-September 2001, Shana Penington, February 2000-August 2000.

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