Summary Information
Mega-Monsoon Experiment (MegaME) Vegetation Sampling Data from the Sevilleta National Wildlife Refuge, New Mexico (2014 - present)
Creator:
Individual: Scott Collins
Organization: SEV LTER
Physical Address:
Delivery Address: Department of Biology, MSC03 2020, 1 University of New Mexico
City: Albuquerque
Locality: NM
Postal Code: 87131
Email: scollins@sevilleta.unm.edu
System ID: 12275
Associated Party:
Individual: Chandra Tucker
Organization: SEV LTER
Email: ctucker@sevilleta.unm.edu
Role: data manager
Associated Party:
Individual: Stephanie Baker
Organization: SEV LTER
Phone: (505) 277-8119
Email: srbaker@sevilleta.unm.edu
Role: field crew
Associated Party:
Individual: Megan McClung
Organization: SEV LTER
Physical Address:
Delivery Address: 1 University of New Mexico, 167 Castetter Hall, MSC03 2020
City: Albuquerque
Locality: NM
Postal Code: 87131
Phone: United States
Email: mmcclung@sevilleta.unm.edu
Role: field crew
Associated Party:
Individual: Chandra Tucker
Organization: SEV LTER
Email: ctucker@sevilleta.unm.edu
Role: field crew
Publication Date: 2015
Language: english
Abstract:
Shrub encroachment is a global phenomenon. Both the causes and consequences of shrub encroachment vary regionally and globally. In the southwestern US a common native C3 shrub species, creosotebush, has invaded millions of hectares of arid and semi-arid C4-dominated grassland. At the Sevilleta LTER site, it appears that the grassland-shrubland ecotone is relatively stable, but infill by creosotebush continues to occur.  The consequences of shrub encroachment have been and continue to be carefully documented, but the ecological drivers of shrub encroachment in the southwestern US are not well known.One key factor that may promote shrub encroachment is grazing by domestic livestock. However, multiple environmental drivers have changed over the 150 years during which shrub expansion has occurred through the southwestern US. Temperatures are warmer, atmospheric CO2 has increased, drought and rainy cycles have occurred, and grazing pressure has decreased. From our prior research we know that prolonged drought greatly reduces the abundance of native grasses while having limited impact on the abundance of creosotebush in the grass-shrub ecotone. So once established, creosotebush populations are persistent and resistant to climate cycles. We also know that creosotebush seedlings tend to appear primarily when rainfall during the summer monsoon is well above average. However, high rainfall years also stimulate the growth of the dominant grasses creating a competitive environment that may not favor seedling establishment and survival. The purpose of the Mega-Monsoon Experiment (MegaME) is twofold. First, this experiment will determine if high rainfall years coupled with (simulated) grazing promote the establishment and growth of creosotebush seedlings in the grassland-shrubland ecotone at Sevilleta, thus promoting infill and expansion of creosotebush into native grassland. Second, MegaME will determine if a sequence of wet summer monsoons will promote the establishment and growth of native C4 grasses in areas where creosotebush is now dominant, thus demonstrating that high rainfall and dispersal limitation prevent grassland expansion into creosotebush shrubland. 
Keywords:
Keyword: primary production
Keyword Thesaurus: Core Areas
Keywords:
Keyword: species
Keyword: precipitation
Keyword: rain
Keyword: species composition
Keyword: growth
Keyword: plant growth
Keyword: species interactions
Keyword: competition
Keyword: grazing
Keyword: grasslands
Keyword: plants
Keyword: grasses
Keyword: seedlings
Keyword: shrubs
Keyword: vegetation
Keyword Thesaurus: LTER Controlled Vocabulary
Additional Information:
Additional Information on the personnel associated with the Data Collection:Stephanie Baker 2014-presentMegan McClung 2014-presentChandra Tucker 2014-present
Intellectual Rights:
Data Policies
This dataset is released to the public and may be freely downloaded. Please keep the designated Contact person informed of any plans to use the dataset. Consultation or collaboration with the original investigators is strongly encouraged. Publications and data products that make use of the dataset must include proper acknowledgement of the Sevilleta LTER. Datasets must be cited as in the example below. Muldavin, E. 2004. Sevilleta LTER Fertilizer NPP Study Dataset. Albuquerque, NM: Sevilleta Long Term Ecological Research Site Database: SEV155. (Date of download) A copy of any publications using these data must be supplied to the Sevilleta LTER Information Manager.
Distribution:
Online:
URL: http://sev.lternet.edu/node/7261
Coverage:
Geographic Goverage:
Geographic Description: Location: The Mega-Monsoon Ecotone site is located just west of the Five Points Black Grama site.Vegetation: This site is dominated by black grama (Bouteloua eriopoda) and creosote. Other prevalent grasses include Sporobolus contractus, S. cryptandrus, S. flexusous, and Muhelnbergia arenicola. ,
Bounding Coordinates:
West Bounding Coordinates: -106.733
East Bounding Coordinates: -106.733
North Bounding Coordinates: 34.333
South Bounding Coordinates: 34.333
Geographic Goverage:
Geographic Description: Location: The Mega-Monsoon Cresoote Site is included within the Five Points Creosote Site.  Vegetation: The Five Points Creosote site is characterized as Chihuahuan Desert Scrub, dominated by a creosote overstory, with broom snakeweed, purple pricklypear (Opuntia macrocentra), and soapweed yucca as co-occurring shrubs. The site is also characterized by numerous, dense, grass-dominated patches, reflecting proximity to the Five Points Black Grama Site. Dominant grasses are black grama, fluffgrass (Dasyochloa pulchellum), burrograss (Scleropogon brevifolia), bushmuhly (Muhlenbergia porteri), and galleta (Pleuraphis jamesii). Notable forbs include field bahia (Bahia absinthifolia), baby aster (Chaetopappa ericoides), plains hiddenflower (Cryptantha crassisepala), Indian rushpea (Hoffmannseggia glauca), Fendlers bladderpod (Lesquerella fendleri), and globemallows (Sphaeralcea spp.).,
Bounding Coordinates:
West Bounding Coordinates: -106.7558
East Bounding Coordinates: -106.7558
North Bounding Coordinates: 34.3331
South Bounding Coordinates: 34.3331
Temporal Coverage:
Date Range:
Begin Date:
Calendar Date: 2014-05-29
End Date:
Calendar Date: 2015-10-27
Contact:
Position Title: Information Manager
Organization: LTER Network Office
Physical Address:
Delivery Address: UNM Biology Department, MSC03-2020
Delivery Address: 1 University of New Mexico
City: Albuquerque
Locality: NM
Postal Code: 87131-0001
Phone: USA
Phone: 505 277-2535
Phone: 505 277-2541
Email: tech-support@lternet.edu
URL: http://www.lternet.edu
Contact:
Individual: Sevilleta Information Manager
Organization: SEV LTER
Email: data-use@sevilleta.unm.edu
Publication Place: Sevilleta LTER
Method Step:
Description:
Data Collection Vegetation and soil measurements are taken in the spring and fall each year. Spring measurements are taken in May when spring annuals have reached peak biomass for the growing season. Fall measurements are taken in either September or October when summer annuals and all perennial species have reached peak biomass for the growing season, but prior to killing frosts. Vegetation cover is measured to assess growth and survival of grasses and shrubs. Bare soil and litter covers are also measured to monitor substrate changes that occur within the plots.One meter2 vegetation quadrats are used to measure the cover of all plants present in each m2.   There are 10 quads in each plot, checkered along on side of the plot.  There is a tag on one rebar of each quad with the representative quad number.   General vegetation measurements The cover is recorded for each species of live plant material inside the quadrat.  Vegetation measurements are taken in two layers: a ground level layer that includes all grasses, forbs, sub-shrubs, and a litter 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 dead plant covers are not included in the measurement, thus the total amount may not equal 100%.  It is assumed that the remaining cover missing from the 100% is a combination of dead plant material. 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 less than 1%. Vegetation cover measurements Cover measurements are made by summing the live 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 less than 1.00%, round the measurements to an increment of 0.1.  Cover values between 1.00% and 10.00% should be rounded to increments of 1.0, and values more than 10.00% are rounded to increments of 5.Creosote Larrea tridentata canopy  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).  ForLarrea seedlings the code LSEED is used and is a separate measurement from the Larrea canopy measurements. The cover measurement for LSEED is simply a count of individuals, not actual cover, as it is assumed that they would have a cover of less than 1.00%.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. 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.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 10.00% 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 “0” for cover.Litter Measure the cover of the area occupied by litter, which is unattached dead plant material.  Cover is quantified by summing the number of 10cm x 10cm squares intercepted by abiotic substrates. Cover values less than 10.00% should be rounded to increments of 1 and cover values more than 10.00% should be recorded in increments of 5.  If there is no litter in the quadrat, record “LITT” in the species column for that quadrat and record a “0” for cover. Clipping grass at Ecotone Site After measurements are taken at the Ecotone Site, grass is clipped down to the soil and removed from half of the quads in each plot. The goal is to assess the impact of competition on successful creosote seedling germination. The following quads, # 2, 4, 6, 7, and 10, get clipped in every plot at the ecotone site. Water Addition The watering schedule varies based on seasonal rainfall. Our goal is to increase average monsoon precipitation (150mm) by 50%, so we shoot for a total of 225mm on the plots during the summer monsoon.
Data Table:
Entity Name: sev259_megame_20151028.txt
Entity Description: Data for SEV259
Object Name: sev259_megame_20151028.txt
Data Format:
Text Format:
Number of Header Lines: 1
Record Delimiter: \r\n
Attribute Orientation: column
Simple Delimited:
Field Delimiter: ,
Distribution:
Online:
URL: https://pasta.lternet.edu/package/data/eml/knb-lter-sev/259/228640/21071c9db708048dafa041a3f10fcfbf
Coverage:
Temporal Coverage:
Date Range:
Begin Date:
Calendar Date: 2014-05-29
End Date:
Calendar Date: 2014-10-23
Attribute List:
Attribute Name: Date
Attribute Label: Date
Attribute Definition: The date of data collection.
Storage Type: date
Measurement Scale:
Datetime:
Format String: DD/MM/YYYY
Attribute Name: Year
Attribute Label: Year
Attribute Definition: The year in which the data were collected.
Storage Type: date
Measurement Scale:
Datetime:
Format String: YYYY
Attribute Name: Season
Attribute Label: Season
Attribute Definition: The season of year that plant/data was collected.
Storage Type: string
Measurement Scale:
Nominal:
Non Numeric Domain:
Enumerated Domain:
Code Definition:
Code: 1
Definition: winter
Code Definition:
Code: 2
Definition: spring
Code Definition:
Code: 3
Definition: winter
Attribute Name: Site
Attribute Label: Site
Attribute Definition: The ecosystem in which data were collected (grassland, shrubland, ecotone of grassland/shrubland, or mixed grassland-shrubland). E and M were used for the same site in different projects, therefore the redundancy.
Storage Type: string
Measurement Scale:
Nominal:
Non Numeric Domain:
Enumerated Domain:
Code Definition:
Code: G
Definition: Grassland
Code Definition:
Code: C
Definition: Shrubland
Code Definition:
Code: M
Definition: Mixed grassland and shrubland
Code Definition:
Code: E
Definition: Ecotone of grassland and shrubland
Attribute Name: Treatment
Attribute Label: Treatment
Attribute Definition: The treatment of given plot and quad.
Storage Type: string
Measurement Scale:
Nominal:
Non Numeric Domain:
Enumerated Domain:
Code Definition:
Code: IG
Definition: plot irrigated/quad grazed
Code Definition:
Code: IC
Definition: plot irrigated/quad control
Code Definition:
Code: CG
Definition: plot control/quad grazed
Code Definition:
Code: CC
Definition: plot control/quad control
Attribute Name: Plot
Attribute Label: Plot
Attribute Definition: Number of plot where data were collected.
Storage Type: string
Measurement Scale:
Nominal:
Non Numeric Domain:
Text Domain:
Definition: Number of plot where data were collected.
Attribute Name: Quadrat
Attribute Label: Quad
Attribute Definition: Quadrat that data were recorded from.
Storage Type: string
Measurement Scale:
Nominal:
Non Numeric Domain:
Text Domain:
Definition: Quadrat that data were recorded from.
Attribute Name: Species
Attribute Label: Species
Attribute Definition: Kartez code for species being sampled based on the USDA plants database.
Storage Type: string
Measurement Scale:
Nominal:
Non Numeric Domain:
Text Domain:
Definition: Kartez code for species being sampled based on the USDA plants database.
Attribute Name: Cover
Attribute Label: Cover
Attribute Definition: Total vegetation canopy cover by species measured on each quadrat.
Storage Type: string
Measurement Scale:
Nominal:
Non Numeric Domain:
Text Domain:
Definition: Total vegetation canopy cover by species measured on each quadrat.
Attribute Name: Comments
Attribute Label: Comments
Attribute Definition: comments
Storage Type: string
Measurement Scale:
Nominal:
Non Numeric Domain:
Text Domain:
Definition: comments