disturbance

Disturbances often shape ecosystems by periodically reorganizing or destroying them, allowing for significant changes in plant and animal populations and communities.

Biomass of Submerge Aquatic Macrophytes Before and After a Catastrophic Fire at the Valles Caldera National Preserve, New Mexico (2011-2012)

Abstract: 

This dataset is about the above ground biomass of submerged aquatic macrophytes (SAMs) collected in 2011 and 2012 from the East Fork Jemez River in the Valles Caldera National Preserve, NM before and after the Las Conchas fire.

Additional Project roles: 

368

Core Areas: 

Data set ID: 

299

Short name: 

epiphytes

Keywords: 

Data sources: 

sev299_macrophytes_20150608.csv

Methods: 

To quantify the production of each species, we calculated the aboveground organic biomass using a standard ash free dry mass (AFDM) procedure. Samples were taken on transects within the ungulate exclosure and were collected approximately every six weeks during each growing season (May-October) to reduce possible cumulative impacts from sampling to the ecosystem. A sampling device for collecting all of the aboveground plant tissues in a known surface area was created for shallow flowing water use based on the Marshall and Lee (1994) basic design. Samples were preserved on ice and transported to the BioAnnex Analytical Laboratories at the University of New Mexico, Albuquerque, NM, USA for analysis. Upon return to the lab, the plant tissue samples were manually separated, and vegetation samples were sorted by taxa. Each individual sample was then sonicated in an ultrasonic water bath filled with deionized water for at least 10 minutes to remove epiphytic organisms. After sonication, each sample was placed in a drying oven at 60oC for 48 hours, then weighed. Approximately 250 mg subsamples were retained from the dried samples and stored in 20 mL glass scintillation vials for later carbon, nitrogen, and phosphorus content analysis. The remaining plant tissue was then fired in a muffle furnace at 500oC for two hours. The AFDM was then calculated and corrected for the removal of the subsample taken for elemental analysis.

Groundwater Well Data from the Middle Rio Grande Valley Riparian Zone, New Mexico (ongoing since 1999)

Abstract: 

This study originated with the objective of parameterizing riparian evapotranspiration (ET) in the water budget of the middle Rio Grande of New Mexico.  We hypothesized that flooding and invasions of non-native species would impact the ecosystem's use of water.  Our objectives were to measure and compare the ET of native (Rio Grande cottonwood, Populus deltoides ssp. wizleni) and non-native (saltcedar, Tamarix chinensis, Russian olive, Eleagnus angustifolia) bosque (woodland) communities and to evaluate how water use is affected by climatic variability resulting in high river flows and flooding as well as drought conditions and deep water tables.  This data set contains water table levels monitored at nine sites along the Rio Grande riparian corridor between Albuquerque and Bosque del Apache National Wildlife Refuge.  Data date to 1999.  Two sites remain active and are well into their second decade of monitoring.  One is in a xero-riparian, non-flooding, saltcedar woodland within the Sevilleta National Wildlife Refuge.  The other is in a dense, monotypic saltcedar thicket at the Bosque del Apache NWR that is subject to flood pulses associated with high river flows.  

Core Areas: 

Additional Project roles: 

400

Data set ID: 

295

Short name: 

Bosque Wells

Keywords: 

Methods: 

Well Design: Water table monitoring wells are installed ~1 m below the baseflow water table. Wells are constructed of 5 cm inner diameter PVC pipe with approximately 1 m long, 0.25 mm slot screen lengths, capped at the bottom.Each site has a network of five wells: A central well (C) and four wells ~40 m from the center well in the four cardinal directions (N, S, E, W). Pressure transducers to log water table levels at 30 minute intervals were deployed in most of the wells at various times.

Water Table Data:

Site data are listed by acronyms, see above, e.g., BDASn = Bosque del Apache south site, north well. Variables include date, time, groundwater temperature recorded by the transducer, if applicable (gw temp, °C), depth to water table from grade at the well (DWT, cm), water table elevation above sea level (WT elev, m, except for the unsurveyed La Joya site), and a quality check (qc) column to indicate estimated data (see below).

Groundwater temperatures range from 8° to 20° C with precision to the nearest tenth of a degree. Water table levels range from 4 m depth to 0.5 m above the surface (inundation) with precision to the nearest mm.

Water table levels collected with the following pressure transducers:


1. Solinst model 3001 LT M10 Leveloggers and model 3001 LT M1.5 Barologgers*, Solinst Canada Ltd., Georgetown, ON, Canada.
2. Schlumberger model DI501 Mini-, model DI701 Cera-, and model DI501 Baro*-Divers, Schlumberger Water Services,Tucson, AZ.
3. EEI Submersible Sensor models 2.0 (2 m) and 5.0 (4m), Electronic Engineering Innovations, Las Cruces, NM. These transducers are vented (no barometric correction required) and do not measure temperature.
*Solinst and Schlumberger submersible transducers measure total pressure (barometric and hydraulic).  Barometric transducers suspended above the water column in a well record barometric pressure, which is subtracted from the total pressure readings to arrive at hydraulic pressure, or well head.

With all data collections, well water levels are manually measured with a Solinst or TestWell sounder and offset-corrected.  Thirty-minute data missing from a time series indicate that a logger was not deployed or a malfunction occurred.  Missing water table data are estimated in some cases, especially when data are lost during the Apr 1 -- Nov 15 growing season and at wells with long-term records.  Estimates are made by:
1. The average rate of change within a time series from data existing before and/or after the gap (e1 in the qc column).
2. The average rate of change from one or more nearby well logs during the gap (e2 in the qc column).
3. Linear regression with one or more of the nearby well logs from data existing before and after the gap (e3 in the qc column).

Survey of location and elevation of wells:

Survey data collected by D. McDonnell, UNM Biology, Feb-Mar 2002, UTM NAD83.
Equipment loaned by University NAVSTAR Consortium (UNAVCO), Boulder, CO.
Equipment used:
Trimble 4000 Receiver Systems (2) $24,000
Trimble 4700 Reciever System (1) $8,000
Trimble Removable Groundplane Antennas (3) $9,000
TSC-1 Controller (1) $5,000
Misc. ancillary equipment $1,000

LARO site only:
GPS data collected by J Thibault & J Cleverly, UNM Biology. Garmin Etrex and Garmin III+, WGS 84. Data not suitable for use in elev calculations at these wells. Coordinates and c well elev are approximations.

Data sources: 

sev295_bosquewells_20150720.csv
sev295_bosquewellslocations_20140520.csv

Additional information: 

SEV--wells associated with the active ET tower at the Sevilleta NWR saltcedar no flood site near San Acacia 1999--present.
BDAS--wells associated with the active ET tower at the Bosque del Apache south NWR saltcedar flood site, 1999--present.      
SHK--wells associated with ET tower (2000--2007) at the Albuquerque South Valley (access from Shirk Lane) cottonwood no flood site, 1999-2013.
LARO--wells associated with ET tower (2003--2008) at the La Joya State Refuge Russian olive and willow flood site, 2003-2009.
BLN-- wells associated with ET tower (2000--2003) at the Belen cottonwood flood site, 1999--2008.
RGNC--wells (no tower) at the Albuquerque Rio Grande Nature Center cottonwood no flood site, 1999--2005.
LL-- wells (no tower) at the Los Lunas cottonwood flood site, 1999--2005.
BDO--wells (no tower) at the Bernardo saltcedar no flood site, 1999--2005.
BDAN--wells (no tower) at the Bosque del Apache north NWR saltcedar flood site, 1999-2005. 

Gunnison's Prairie Dog Restoration Experiment (GPDREx): Vegetation Cover Data from the Sevilleta National Wildlife Refuge, New Mexico (2011 - present)

Abstract: 

Prairie dogs (Cynomys spp.) are burrowing rodents considered to be ecosystem engineers and keystone species of the central grasslands of North America. Yet, prairie dog populations have declined by an estimated 98% throughout their historic range. This dramatic decline has resulted in the widespread loss of their important ecological role throughout this grassland system. The 92,060 ha Sevilleta NWR in central New Mexico includes more than 54,000 ha of native grassland. Gunnison’s prairie dogs (C. gunnisoni) were reported to occupy ~15,000 ha of what is now the SNWR during the 1960’s, prior to their systematic eradication. In 2010, we collaborated with local agencies and conservation organizations to restore the functional role of prairie dogs to the grassland system. Gunnison’s prairie dogs were reintroduced to a site that was occupied by prairie dogs 40 years ago.  This work is part of a larger, long-term study where we are studying the ecological effects of prairie dogs as they re-colonize the grassland ecosystem.

Data set ID: 

238

Core Areas: 

Additional Project roles: 

486
487
488
489
490

Keywords: 

Methods: 

Experimental Design

Two replicate paired 16 ha plots were established in spring 2010. Each pair consists of a treatment plot with prairie dogs (reintroduced), which are plots B and D and a control plot with no prairie dogs (plots A and C).  There are 4 other plots (E,F,G, and H) but they are not set up to do vegetation sampling. 

Sampling Periods

 Baseline vegetation sampling occurred at the end of April 2010. A second sampling was done at the end of September 2011.  There was no other vegetation sampling until September 2013, at which time it will be collected consistently every spring and fall. 

Field Procedures 

Percent live plant canopy cover and height of live foliage of all plant species are measured using 0.25 m2 vegetation sampling quadrats at the end of the growing season each spring (late April) and late summer (early September).  The 50x50 cm vegetation measurement frame has a string grid which partitions the frame into 25, 10x10 cm squares. One quarter of a 10x10 cm grid cell equals 1% cover. Therefore each 10x10 cm cell has a 4% cover value. Vegetation measurements range from 0.1 to 100%. A cover of 0.1 represents a plant species trace occurrence on the quad. The next smallest measurement is 1%, or ¼ of a 10x10 cm grid cell. Cover is measured to the nearest 1% for 1-10% cover and to the nearest 5% for 10-100% cover. Total cover for a particular plant species is measured by counting the number of 10x10 cm cells occupied by the foliage canopy, multiplying that value by 4 and rounding to the nearest 5% for total cover greater than 10%. Typical maximum plant canopy height for each species is also measured to the nearest centimeter.

Data sources: 

sev238_pdogvegcover_20151204.txt

Additional information: 

More information about who is involved with the samples/data:

Terri Koontz 2010

Amaris Swann 2011

John Mulhouse 2011

Stephanie Baker 2011-present

Megan McClung 2013-present

Chandra Tucker 2014-present

Study Site Information: 

The SevLTER Prairie Dog Project 16 ha study plots are located east of the Blue Grama Core site at the foothill of the Los Pinos Mountains and along Test Well Road. It is a grassland dominated by blue grama grass, with associated grass species consisting of black grama, galleta, purple three-awn, sand muhly, and dropseed. Yucca and Cholla cactus are the dominant shrubs at the site.

Ecosystem-scale rainfall manipulation in a Pinon-Juniper woodland: Tree Sapwood and Leaf Area Data (2011)

Abstract: 

Climate models predict that water limited regions around the world will become drier and warmer in the near future, including southwestern North America. We developed a large-scale experimental system that allows testing of the ecosystem impacts of precipitation changes. Four treatments were applied to 1600 m2 plots (40 m × 40 m), each with three replicates in a piñon pine (Pinus edulis) and juniper (Juniper monosperma) ecosystem. These species have extensive root systems, requiring large-scale manipulation to effectively alter soil water availability. Treatments consisted of: 1) irrigation plots that receive supplemental water additions, 2) drought plots that receive 55% of ambient rainfall, 3) cover-control plots that receive ambient precipitation, but allow determination of treatment infrastructure artifacts, and 4) ambient control plots. Our drought structures effectively reduced soil water potential and volumetric water content compared to the ambient, cover-control, and water addition plots. Drought and cover control plots experienced an average increase in maximum soil and air temperature at ground level of 1-4° C during the growing season compared to ambient plots, and concurrent short-term diurnal increases in maximum air temperature were also observed directly above and below plastic structures. Our drought and irrigation treatments significantly influenced tree predawn water potential, sap-flow, and net photosynthesis, with drought treatment trees exhibiting significant decreases in physiological function compared to ambient and irrigated trees. Supplemental irrigation resulted in a significant increase in both plant water potential and xylem sap-flow compared to trees in the other treatments. This experimental design effectively allows manipulation of plant water stress at the ecosystem scale, permits a wide range of drought conditions, and provides prolonged drought conditions comparable to historical droughts in the past – drought events for which wide-spread mortality in both these species was observed. The focus of this study was to determine the effects of rainfall manipulation on our two target tree species.  Therefore, the analysis of the water relations of these trees was an essential component of the project.  Sap-flow within each individual target tree was monitored through the use of Granier probes.  These monitoring efforts provided a window on processes such as transpiration and the night-time re-filling of the xylem tissue.  Drought tolerance and adaptation strategies were also explored by comparing differences in sap-flow rates across treatment types and between species.

Data set ID: 

288

Core Areas: 

Additional Project roles: 

384
385
386
387
388
389
390
391

Keywords: 

Methods: 

Site Description In total, our study site consisted of 12 experimental plots located in three replicate blocks that varied in slope % and aspect. The study utilized four different experimental treatments applied in three replicate blocks. The four experimental treatments included;1) un-manipulated, ambient control plots, 2) drought plots, 3) supplemental irrigation plots, and 4) cover-control plots that have a similar infrastructure to the drought plots, but remove no precipitation. The three replicated blocks differed in their slope and aspect. One block of four plots was located on south facing slopes, one on north facing slopes, and one in a flat area of the landscape.

Experimental Treatment Design (see Pangle et al. 2012 for detailed methodology) 

To effectively reduce water availability to trees, we installed treatments of sufficient size to minimize tree water uptake from outside of the plot.  Thus, we constructed three replicated drought structures that were 40 m × 40 m (1600 m2). We targeted a 50% reduction in ambient precipitation through water removal troughs that covered ~50% of the land surface area. Drought plot infrastructure was positioned to insure that targeted Piñon pine and juniper were centrally located within each drought plot to provide the maximum distance between tree stems and the nearest plot boundary.  Each drought and cover-control plot consists of 27 parallel troughs running across the 40 m plot. Each trough was constructed with overlapping 3ft ×10 ft (0.91 m × 3.05 m) pieces of thermoplastic polymer sheets (Makloron SL Polycarbonate Sheet, Sheffield Plastics Inc, Sheffield, MA) fixed with self-tapping metal screws to horizontal rails that are approximately waist height and are supported by vertical posts every 2.5-3.5 m. The plastic sheets were bent into a concave shape to collect and divert the precipitation off of the plot. The bending and spacing of the plastic resulted in 0.81 m (32 in) troughs separated by 0.56 m (22 in) walkways.  Individual troughs often intersected the canopy of trees because of their height. The troughs were installed as close to the bole of the tree as possible without damaging branches in order to maximize the area covered by the plastic across the entire plot. An end-cap was attached to the downstream edge of the trough to prevent water from falling onto the base of the tree.  A piece of 3 in (7.62 cm) PVC pipe or suction hose (used when the bole of a tree was directly below trough) was then attached to the downstream side of the end-cap, enabling water to flow into the trough on the other side of a tree. End-caps were also placed at the downhill end of the troughs on the edge of the plot and fitted with 90 degree fittings to divert water down into a 30 cm2 gutter (open on top) that ran perpendicular to the plot. Collected water was then channeled from the gutter into adjacent arroyos for drainage away from the study area.

 

We built cover-control infrastructures to investigate the impact of the plastic drought structures independent of changes in precipitation. This was necessary because of the high radiation environment in central New Mexico, in which the clear plastic troughs can effectively act as a greenhouse structure. The cover-control treatment had the same dimensions as the drought plots with one key difference. The plastic was attached to the rails in a convex orientation so precipitation would fall on top of the plastic and then drain directly down onto the plot. The cover-control plots were designed to receive the same amount of precipitation as un-manipulated ambient plots, with the precipitation falling and draining into the walkways between the rows of troughs. Cover-control plots were constructed between June-21-07 and July-24-07; drought plots were constructed between August-09-07 and August-27-07.  The total plastic coverage in each plot is 45% ± 1% of the 1600 m2 plot area due to the variable terrain and canopy cover.

 

Our irrigation system consisted of above-canopy sprinkler nozzles configured to deliver supplemental rainstorm event(s) at a rate of 19 mm hr-1. Our irrigation system is a modified design of the above-canopy irrigation system outlined by Munster et al. (2006). Each of the three irrigation plots has three 2750 gal (10.41 m3) water storage tanks connected in parallel.  These tanks were filled with filtered reverse osmosis (RO) water brought to the site with multiple tractor-trailer trucks. During irrigation events, water is pumped from the tanks through a series of hoses attached to 16 equally-spaced sprinklers within the plot. Each sprinkler is 6.1 m (20 ft) tall (2-3 m higher than mean tree height), and fitted with a sprinkler nozzle that creates an even circular distribution of water with a radius of 5 m on the ground.  The irrigation systems were tested in October 2007 (2 mm supplemental), and full applications (19 mm) were applied in 2008 on 24-June, 15-July, and 26-August. During subsequent years (2009-2012), a total of four to six irrigation events (19mm each) were applied (please contact Will Pockman and/or Robert Pangle for specific application dates and rates).  

Tree Survey

For each 1600 m2 plot, all PIED and JUMO trees (> 0.5 cm diameter) were surveyed and inventoried in spring 2011. For each tree, a designation of alive or dead at the time of the 2011 survey was recorded. Trees that were dead prior to the initiation of the 2006 project (i.e., snags) were excluded from the survey records. The tree tag number for target trees in each plot is the plot and tree number (example, P1T1). Non-target trees in each plot were tagged with a random number using a stamped metal tag. Tree diameter was measured at 30cm stem height and for trees with multiple stems at 30 cm height - a single equivalent diameter was calculated and recorded. Tree basal area was calculated using stem diameter at 30cm. Tree sapwood area and tree leaf area were calculated using site specific allometric equations that were developed in 2006 (using stem diameter as the predictor variable). Accordingly, tree sapwood area and tree leaf area reflect biometric conditions that existed at the initiation of treatments in 2007. Crown diameter was directly measured on all inventoried trees. PIED and JUMO comprised the overwhelming majority of the woody canopy cover at this PJ-woodland site. Accordingly, very little of the total basal area, stem sapwood area, or canopy leaf area was comprised of other woody species at this site (thus, any non-PIED or non-JUMO data is not shown since it comprised an extremely small % of the total woody biomass in these plots.)

The treatment classes provided in the file are as follows; ambient (1), drought (2), cover-control (3), and irrigation (4). The experiment used plot aspect as the blocking factor. There are 3 different replicate blocks and block classifications designated in the files; flat aspect (1), north aspect (2), and south aspect (3). This will be obvious when viewing the files.

Tree numbers are always grouped by species as follows (regardless of plot); Trees 1-5 are original Pinus edulis, Trees 6-10 are original Juniper monosperma. When one of these original trees died, an additional tree in the plot was added to retain an adequate sample size over time (i.e., multiple years+). These additional trees are grouped as follows; Trees 11-15 are “replacement” Pinus edulis, Trees 16-20 are “replacement” Juniper monosperma. “Replacement” is used here in a more restricted sense, as these additional trees have their separate and unique tree designation number.

So, in differing plots you will have differing numbers of target trees depending on; 1) the number of trees for which data was collected, and 2) how many additional “replacement trees” had to be designated due to mortality (or partial mortality) of original trees. Many plots have n=10 trees, based on the original T1-T5 & T6-10 designation, as these particular plots did not experience mortality. However, a plot like P10 has a total of n=16 trees. In P10, the original T1-5 & T6-T10 trees are listed, a replacement Pinon (T11) is listed, and five additional/replacement junipers (T16-T20).

Data sources: 

pj_treesurvey_20130506.csv

Quality Assurance: 

Data processing and QA-QC were performed using either Matlab (The Mathworks, Inc.) or Microsoft Office 2010 Excel (Microsoft Corporation) software.  All raw and/or processed data traces were visually plotted and inspected for noisy, erroneous, or out of range data points or sensors traces.  All removed data points had a “NaN” value assigned.   Despite this QA-QC review and data cleaning, all data sets should still be evaluated for outliers, etc., as standard outlier statistical tests were not performed.

Water Potential Data From Pinyon-Juniper Forest at Sevilleta National Wildlife Refuge, New Mexico

Abstract: 

This dataset consists of profiles of soil water potential measured via in situ thermocouple psychrometers located within a rainfall manipulation experiment in a piñon-juniper woodland. The sensors are centrally located within 40 m x 40 m water addition, water removal, infrastructure control, and ambient control plots. The profiles are installed under each of ten target piñon and juniper trees (five of each species) which were also used for other physiological measurements, as well as at five intercanopy areas. The raw sensor output (in μV) has been temperature-corrected and individual calibration equations applied.

Background: This sensor array is part of a larger experiment investigating the mechanisms of drought-related mortality in the piñon-juniper woodland. Briefly, one hypothesis is that, during periods of extended, very-negative, soil water potential (“drought”) trees experience xylem tensions greater than their threshold for cavitation, lose their hydraulic connection to the soil, dessicate and die. A second hypothesis is that in order to avoid this hydraulic failure, trees restrict water loss via reduction in stomatal conductance which also limits the diffusion of CO2 for photosynthesis, and eventually may starve to death depending on the drought duration. 

The goal of the project is to apply drought stress on an area significantly larger than the scale of individual trees to determine whether hydraulic failure or carbon starvation is a more likely mechanism for mortality under drought conditions. The cover control treatment replicates the microenvironment created under the plastic rainfall removal troughs (slightly elevated soil and air temperatures and relative humidity) without removing ambient precipitation. The water addition treatment is intended to simulate 150% of the 30-yr average rainfall via n = 6 19-mm super-canopy applications during the growing season (April-October). More details on the experiment can be found in Pangle et al. 2012 Ecosphere 3(4) 28 (http://dx.doi.org/10.1890/ES11-00369.1). These three treatments, in addition to an ambient control with no infrastructure, are applied to three replicated blocks, one on relatively level terrain, one on a southeast-facing slope, and one on a north-facing slope. The soil psychrometers were installed in the southeast-facing block only, to measure the effectiveness of the treatments on plant-available soil moisture.

For the purposes of comparing soil water potential under various cover types (piñon, juniper, intercanopy), it should be noted that significant tree mortality has occurred on Plot 10. As described below, on 5 August 2008 the site was struck by lightening and many of the soil psychrometers were rendered inoperable. At approximately the same time, four of the five target piñon trees in the southeast-facing drought plot (Plot 10) started browning and it was discovered that they had bark beetle (Ips confusus) galleries and were infected with Ophiostoma fungi. By October 2008 those trees (T1, T2, T4, and T5) had dropped all their needles. Therefore the psychrometers buried under them were no longer located “under trees” after that time. By June 2009 the remaining target piñon (T3) died. By March 2010, one of the target juniper trees (T10) had died. At the time of this writing (April 2011) it is anticipated that more of the juniper trees on P10 will die during this year. 

Data set ID: 

285

Additional Project roles: 

30

Core Areas: 

Keywords: 

Methods: 


Methods:  Within Plots 9-12 of the larger PJ rainfall manipulation experiment, thermocouple psychrometers (Wescor Inc., Logan, UT, USA) were installed. Soil psychrometers profiles were placed under each of the initial ten target trees in each plot, and at the same five intercanopy areas that were instrumented to measure soil and air temperature and soil volumetric water at 5 cm depth. Each profile consisted of sensors at (1) 15 cm; (20) cm; and (3) as deep as could be augered and installed by hand, generally 50-100 cm depth. Sensors were calibrated with four NaCl solutions of known water potential before field deployment.

Sensors are controlled via a Campbell Scientific CR-7 datalogger (Campbell Scientific, Logan, UT, USA). The datalogger takes measurements every 3 h but soil water potential does not change that fast and the daytime measurements are generally unusable because of thermal gradients between the datalogger and the sensors, therefore the data presented here are only the 3:00 AM timepoints.

Note that on 5 August 2008 the site was struck by lightening. Many of the soil psychrometers were destroyed by ground current, with the worst damage on the drought and cover control plots where the metal support posts for the infrastructure may have helped to propagate ground current. Some of those sensors were eventually replaced but in the case of the infrastructure plots we were limited to installing new sensors between the plastic troughs because it was impossible to auger under the plastic. Therefore, while the original installation was random with regard to the pattern of plastic domes and troughs, the replacement installation was exclusively outside the plastic and the data may therefore be biased towards wetter microsites.

Instrumentation: 


Instrument Name: thermocouple psychrometer with stainless steel screen

Manufacturer: Wescor, Inc, Logan, UT, USA

Model Number: PST-55

The response of stream metabolism (productivity and respiration) to variable climate patterns (El Nino and La Nina) using in-situ instrumentation in the Valles Caldera National Preserve, New Mexico

Abstract: 

In the southwestern United States two important seasons influence stream flow: snowmelt in spring and summer monsoonal rainfall events. Flow patterns exhibit peak discharge from snowmelt runoff in the spring followed by pulsed increases in stream discharge during late summer monsoons. Molles and Dahm showed the intensity of the snowmelt discharge is linked to El Nino-Southern Oscillation (ENSO) conditions in the tropical Pacific. El Nino and La Nina climate patterns also may affect late summer monsoonal precipitation in New Mexico by intensifying the monsoon during La Nina years and weakening monsoons during El Nino years. Stage gage data show seasonal and interannual variability in the intensity of snowmelt and monsoonal runoof events in montane catchments in New Mexico. Further, in-situ YSI sonde, Satlantic Submersible Ultraviolet Nitrate Analyzer (SUNA) and CycleP instrumentation show physical and chemical constituents respond to higher flow events driven by climate variability, and the constituents these instruments measure can be used as a proxy to estimate whole stream metabolism and nutrient cycling processes.

Data set ID: 

282

Core Areas: 

Additional Project roles: 

12
13
14
15

Keywords: 

Data sources: 

sev282_streammetabolism_08062012.txt

Methods: 

Data Selection: Historical flux tower data from 2007 to 2011 was provided by UNM Marcy Litvak for two locations near our study site on the EFJR.  Los Alamos National Lab provided flux data from 2005 to 2006.  Flux towers provided photosynthetic active radiation (PAR) and barometric pressure in 30 minute time intervals.  In-stream YSI sondes continuously monitored the Jemez and East Fork Jemez Rivers in 15 minute time intervals collecting water quality data (dissolved oxygen, pH, turbidity, specific conductance, water temperature).

Instrumentation: 

Instrument Name: YSI Sonde Manufacturer: YSI IncorporatedModel Number: 6920V2-0

Quality Assurance: 

Sonde and flux data were QAQC'd using Aquarius software to delete suspicious data (or outliers) and to correct for drift from biofouling on probes.

Additional information: 

Study Area Name:  East Fork Jemez River

Study Area Location:  Valles Caldera National Preserve, New Mexico

Study Area Description: 

Elevation: 2582 meters

Landform: Montane grassland, caldera

Geology: Volcanic

Soils: Rich organic soils; Mollisols

Hydrology: snowpack(winter) and monsoonal rainfall (summer)

Vegetation: grassland, meadow

            Climate: Semi-arid

Site history: Domestic grazing of sheep from mid-1800's to 1940's, then cattle by 1940's.

Single Point:  EFJR at Hidden Valley (from VCNP)

North Coordinate: 35.83666667

West Coordinate: -106.5013833

Response of Larrea tridentata to a Natural Extreme Cold Event at the Sevilleta National Wildlife Refuge, New Mexico

Abstract: 

Shrub expansion into grasslands can cause abrupt changes in ecosystem processes. Creosote (Larrea tridentata) is a native shrub in warm, arid deserts of the southwestern US and has taken over C4 grasslands. A limited freeze tolerance is thought to dictate the northern boundary of creosote and the Sevilleta National Wildlife Refuge occurs near to the northern extent of creosote. Cold temperatures are known to damage creosote. In laboratory trials, temperatures of -25 for 1 hour lead to xylem damaging embolism in nearly 100% of stems and temperatures of -24 C lead to seedling death in the lab. Sevilleta LTER meteorological data from a station located within creosote shrublands indicated a low temperature of -20 C between 1999 and 2010. On February 3, 2011 temperatures hit record lows in central New Mexico, reaching -30 C at shrublands within the SNWR. To address how creosote responds to a natural extreme cold events, plots were established to monitor creosote initial response and regrowth following the cold event. Initial surveys will determine canopy death and subsequent surveys of the same individuals will allow us to determine how creosote responds to record cold temperatures.

Core Areas: 

Additional Project roles: 

45

Data set ID: 

244

Keywords: 

Methods: 

Plots were established at 6 locations across SNWR. Criteria for site selection included the presence of L. tridentata, flat terrain to limit microtopographic impacts, close proximity to existing meteorological stations, and variation in shrub density between sites. At each site, approximately 200 shrubs were evaluated within circular plots (20m in diameter) with the number of plots at each site varying in shrub density. Initial surveys to determine canopy death were conducted in early April 2011. These surveys consisted of tagging each shrub with an unique ID, estimating canopy death, and measuring maximum canopy height, maximum width and the perpendicular width to max width.

Additional information: 

Study Area 1:  

Study Area Name:  South Gate

Study Area Location: Located across the road from the met station located at South Gate.

Bounding Box:  

North Coordinate:  34.42

South Coordinate: 34.19

East Coordinate: -106.513

West Coordinate: -107.08

Study Area 2:  

Study Area Name: Microwave shrubland

Study Area Location: Located near the Microwave tower on the West side of the SNWR. Plots are located 100 to 200 m down the road just East of the tower towards Red Tank. Plots are on the West side of the road.

Bounding Box:  

North Coordinate: 34.42

South Coordinate: 34.19

East Coordinate: -106.518

West Coordinate: -107.08

Study Area 3:  

Study Area Name: BurnX shrubland site

Study Area Location: Located near Met station 52b, established near the burn enclosure (BurnX) Black Grama site.

Bounding Box:  

North Coordinate:  34.42

South Coordinate: 34.19

East Coordinate: -106.513

West Coordinate: -107.08

The distribution, structure and function of mesic savanna grasslands are strongly driven by fire regimes, grazing by large herbivores, and their interactions. There is evidence to suggest, however, that fire and grazing influence savanna grassland structure and function differently in South Africa (SA) compared to North America (NA). These differences have been attributed to the contingent factors of greater biome age, longer evolutionary history with fire and grazing, reduced soil fertility, and greater diversity of plants and large herbivores in SA.


Scaling of Recruitment with Seed Distribution and Colony Size in Pogonomyrmex spp. at the Sevilleta National Wildlife Refuge, New Mexico

Abstract: 

Ant colonies possess a “societal metabolism,” acquiring, transforming, and allocating resources through a network of foragers (Moses, 2005). Ant foraging- trail networks channel foragers to known food resources and away from competing colonies (Jun et al., 2003). Computer models suggest the spread of information occurs faster in larger colonies of harvester ants, genus Pogonomyrmex (Adler and Gordon, 1992), providing a possible mechanism of differentiation. Does the ability to utilize and share information scale super-linearly with a colony’s size? Within colonies, do foragers recruit more to denser sources of food, using information transfer to increase forager efficiency and harvest seed caches before competing colonies find them? To address these questions, we studied three sympatric species of Pogonomyrmex in central New Mexico that differ in average colony size: P. rugosus, P. maricopa, and P. desertorum. We hypothesized a) that across colonies recruitment to dense food resources scales positively with colony size, and b) that within colonies recruitment scales positively with seed density. We observed baited colonies for 1 hr, tracking the capture of dyed seeds arranged in piles of different densities and of native seeds. We generated a model of idealized effects of recruitment on foraging patterns and compared the output to our observations. We did not find support for hypothesis a, that recruitment scales positively with colony size, but did find support for hypothesis b, that recruitment does scale positively with increasing seed density. These findings highlight a key intersection between the metabolism of energy and of information.

Core Areas: 

Data set ID: 

235

Keywords: 

Purpose: 

To explore whether large ant colonies are "smarter" and how colonies use recruitment.

Methods: 

Experimental Design: Our experimental design consisted of testing potential differences in forager recruitment by baiting actively foraging colonies with dyed seeds arranged in different distributions (i.e. piles of different numbers of seeds) around each colony. Differences in the rate foragers collect seeds of different colors indicate potential differences in the rate foragers are recruited, by chemical pheromone trails, to piles of different sizes. We conduct these experiments on a number of colonies of three species of Pogonomyrmex that differ in average colony size, and then compare the rates those species retrieve seeds of different distributions.

Field Methods: We located actively foraging Pogonomyrmex colonies between 8 and 9am and distributed dyed millet seeds in a wide circular swath around each colony. We used 256 millet seeds of each color for P. rugosus and P. maricopy and 32 sesame seeds of each color for P. desertorum, which is smaller and has smaller colonies. For each color, we divided those seeds into piles as follows: red = 1 pile; purple = 4 piles; green = 16 piles; blue = "piles" of one seed each (i.e. scattered at random within the circular swath). We then sat near the nest entrance and recorded the seeds brought in by foraging ants. Using a Java program (SeedCounter) we recorded the color and time of each seed retrieved by the focal colony during an observation period of 1 to 1.5 hours. We generated seed uptake curves from this data.

Laboratory Procedures: We also developed an ant foraging simulation. Virtual ants start at a nest entrance at the center of a bounded lattice. The lattice contains 256 randomly distributed blue seeds and a single pile of 256 red seeds. A foraging ant searches at random until it collects a seed, then delivers it to the nest. To model patch fidelity, a successful forager returns to location it found its previous seed and begins a new random search.

Lightning Strike Data for New Mexico, 1997

Abstract: 

This file contains 1997 daily lightning activity data for the state of New Mexico. These data were collected by a network of lightning detection stations scattered throughout the western United States. More information regarding the LLP Lightning Locating System can be found in Maier et al. (1983).

Core Areas: 

Data set ID: 

31997

Keywords: 

Purpose: 

This file contains 1997 daily lightning activity data for the state of New Mexico. These data were collected by a network of lightning detection stations scattered throughout the western United States. More information regarding the LLP Lightning Locating System can be found in Maier, et.al. (1983).

Methods: 

Only data on cloud-to-ground lightning flashes are recorded in this file. Note that each cloud-to-ground lightning flash is composed of one or more highly energetic discharges known as return strokes. Thus each lightning observation found in this file contains a column showing the number of return strokes associated with each flash. In addition, each observation includes information on the time of the flash, location (latitude/longitude), polarity, and signal amplitude. The lightning flash location is determined by triangulation. The accuracy of the flash location is dependent on the number of stations detecting the flash, the flash location with respect to the detecting stations (i.e., poor accuracy if on the baseline between two stations), and the distance between the detecting stations. When the detecting stations are 50 miles apart, estimated strike locations are usually within 1/2 to 1 kilometer of the actual location.

The local lightning detection stations are located at:

LOCATION LATITUDE LONGITUDE

Albuquerque 34.9475 -106.5590

Socorro 34.0682 -106.9139

Roswell 33.3076 -104.5274

Gallup 35.5126 -108.7768

These data are bounded by the following coordinates:

Latitude: 31.335 to 36.999 degrees

Longitude: -109.048 to -103.006 degrees

Data sources: 

sev003_lightning_1997_12092011.txt

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