water

Monsoon Rainfall Manipulation Experiment (MRME) Soil Temperature, Moisture and Carbon Dioxide Data from the Sevilleta National Wildlife Refuge, New Mexico (2012- present)

Abstract: 

The Monsoon Rainfall Manipulation Experiment (MRME) is designed to understand changes in ecosystem structure and function of a semiarid grassland caused by increased precipitation variability, by altering rainfall pulses, and thus soil moisture, that drive primary productivity, community composition, and ecosystem functioning. The overarching hypothesis being tested is that changes in event size and frequency will alter grassland productivity, ecosystem processes, and plant community dynamics. Treatments include (1) a monthly addition of 20 mm of rain in addition to ambient, and a weekly addition of 5 mm of rain in addition to ambient during the months of July, August and September. It is predicted that changes in event size and variability will alter grassland productivity, ecosystem processes, and plant community dynamics. In particular, we predict that many small events will increase soil CO2 effluxes by stimulating microbial processes but not plant growth, whereas a small number of large events will increase aboveground NPP and soil respiration by providing sufficient deep soil moisture to sustain plant growth for longer periods of time during the summer monsoon.

Core Areas: 

Data set ID: 

304

Keywords: 

Methods: 

Experimental Design

MRME contains three ambient precipitation plots and five replicates of the following treatments: 1) ambient plus a weekly addition of 5 mm rainfall, 2) ambient plus a monthly addition of 20 mm rainfall. Rainfall is added during the monsoon season (July-Sept) by an overhead (7 m) system fitted with sprinkler heads that deliver rainfall quality droplets. At the end of the summer, each treatment has received the same total amount of added precipitation, delivered in different sized events. Each plot (9x14 m) includes subplots (2x2 m) that receive 50 kg N ha-1 y-1. Each year we measure: (1) seasonal (July, August, September, and October) soil N, (2) plant species composition and ANPP, (3) annual belowground production in permanently located root ingrowth cores, and (4) soil temperature, moisture and CO2 fluxes (using in situ solid state CO2 sensors).

Soil Measurements

Soil temperature is measured with Campbell Scientific CS107 temperature probes buried at 2 and 8 cm In the soil. Soil volume water content, measured with Campbell Scientific CS616 TDR probes is an integrated measure of soil water availability from 0-15 cm deep in the soil. Soil CO2 is measured with Vaisala GM222 solid state CO2 sensors. For each plot, soil sensors are placed under the canopy of B. eriopoda at three depths: 2, 8, and 16 cm. Measurements are recorded every 15 minutes.

CO2 fluxes are calculated using the CO2, temperature, and moisture data, along with ancillary variables following the methods of Vargas et al (2012) Global Change Biology

Values of CO2 concentration are corrected for temperature and pressure using the ideal gas law according to the manufacturer (Vaisala). We calculate soil respiration using the flux-gradient method (Vargas et al. 2010) based on Fick’s law of diffusion where the diffusivity of CO2 is corrected for temperature and pressure (Jones 1992) and calculated as a function of soil moisture, porosity and texture (Moldrup et al. 1999).

Data sources: 

sev304_mrme_soiltemp_moisture_co2_2012
sev304_mrme_soiltemp_moisture_co2_2013
sev304_mrme_soiltemp_moisture_co2_2014
sev304_mrme_soiltemp_moisture_co2_2015

Instrumentation: 

Instrument Name: Solid State Soil CO2 sensor
Manufacturer: Vaisala
Model Number: GM222

Instrument Name: Temperature Probe
Manufacturer: Campbell Scientific
Model Number: CS107

Instrument Name: Water Content Reflectometer Probe
Manufacturer: Campbell Scientific
Model Number: CS616

Additional information: 

Additional Study Area Information

Study Area Name: Monsoon site

Study Area Location: Monsoon site is located just North of the grassland Drought plots

Vegetation: dominated by black grama (Bouteloua eriopoda), and other highly prevalent grasses include Sporabolus contractus, S.cryptandrus, S. lexuosus, Muhlenbergia aernicola and Bouteloua gracilis.

North Coordinate:34.20143
South Coordinate:34.20143
East Coordinate:106.41489
West Coordinate:106.41489

Developing an understanding of vegetation change and fluvial carbon fluxes in semi-arid environments: Soil moisture data

Abstract: 

Dryland environments are estimated to cover around 40% of the global land surface, and are home to approximately 2.4 billion people. Many of these areas have recently experienced extensive land degradation. This study focuses on semi-arid areas in the US Southwest, where degradation over the past 150 years has been characterized by the invasion of woody vegetation into areas previously dominated by grasslands. This vegetation change has been associated with increases in soil erosion and water quality problems, including the loss of key nutrients such as carbon from the soil to adjacent fluvial systems. Such loss of resources may impact heavily upon the amount of carbon that is lost as the land becomes more heavily degraded. 

Therefore, understanding these vegetation transitions is significant both for sustainable land use and global biogeochemical cycling. This study uses an ecohydrological approach to develop an understanding of the relationship between structure and function across these transitions. This is done via the monitoring of rainfall-runoff events across instrumented runoff plots with different vegetation characteristics to investigate fluvial sediment fluxes during intense summer monsoon season rainfall events.

Data set ID: 

252

Core Areas: 

Additional Project roles: 

49

Keywords: 

Methods: 

Experimental design:

Each study area consisted of a 10m wide, 30m long, downslope runoff plot, bound at the top and sides with aluminum flashing and fitted with water collecting guttering at the bottom so inputs and outputs could be quantified. The guttering fed water into a flume fixed into the ground at 4⁰ allowing water leaving the plot as runoff to be quantified.

The flumes were instrumented with a pump sampler to collect runoff samples leaving the plot and a bubbler module to measure discharge. In addition all runoff and associated sediment was collected in a covered stock tank (560 gallons for study area 1&2, 1000 gallons for study are 3). Rainfall onto the plot was measured using tipping-bucket rain gauges connected to the pump sampler. Following rainfall events all data was downloaded from the sampler using Flowlink v3.2 software.

Eroded sediment was collected from stock tank following rainfall events, coarse organic matter was removed via flotation, samples were oven dried at 60⁰C, weighed and sieved for particle size analysis using US. standard sieves at the Sevilleta LTER field station.

Setting up plots:

Plots were selected on comparable planar slopes in areas believed to be representative of endmember vegetation habitats.

Instrumentation: 

Instrument Name: Pump samplers fitted with bubbler modules

Manufacturer: ISCO

Model Number: Model 6700 pump samplers and attached model 730 bubbler modules

Instrument Name: Tipping-bucket rain gauges

Manufacturer: ISCO

Model Number: 674

Instrument Name: Flowlink software

Manufacturer: ISCO

Model Number: Version 3.2

Instrument Name: Sieve set and shaker

Manufacturer: unknown/various (from Sevilleta LTER field station)

Model Number: US. Standard: 12mm, 4mm, 2mm, 1mm, 0.5mm, 0.063mm

Additional information: 

This data was collected and analyzed by Alan Puttock as part of the PhD project: ‘Developing an understanding of vegetation change and fluvial carbon fluxes in semi-arid environments’. This project is supervised by Dr Richard Brazier, Dr Jenifer Dungait and Dr Kit Macleod. Analysis of samples/data is being carried out at the University of Exeter and North Wyke Research, United Kingdom.

This data was collected under USFWS permit number: 22522 10-026

 
Study Area 1:  
Study Area Name: Grass Endmember Plot
Study Area Location: Five Points Grass core site (exact point location of plot provided below)
Single Point:  
North Coordinate: 34.339186     
West Coordinate: -106.728303
Study Area 2:  
Study Area Name: Creosote Endmember plot
Study Area Location: Five Points Creosote core site (exact point location of plot provided below)
Single Point:  
North Coordinate: 34.338443
West Coordinate: -106.738020
Study Area 3:  
Study Area Name: Piñon-Juniper Endmember Plot
Study Area Location: Cerro Montoso core site (exact point location of plot provided below)
Single Point:  
North Coordinate: 34.231197
West Coordinate: -106.313741

Comparative Hydraulic Performance of Piñon and Juniper in a Rainfall Manipulation Experiment at the Sevilleta National Wildlife Refuge, New Mexico

Abstract: 

From 2000-2003, extreme drought  across the Southwestern US resulted in widespread tree mortality: piñon pine (Pinus edulis) experienced up to 95% mortality while juniper (Juniperus monosperma) mortality was 25% or less at surveyed sites.  Field data have shown repeatedly that piñon typically exhibits isohydric regulation of leaf water potential, maintaining relatively constant leaf water potentials even as soil water potentials fluctuate, while juniper is anisohydric, allowing leaf water potential to decline during drought.  The goal of this study was to elucidate functional consequences of these two contrasting hydraulic strategies.  The study was conducted in the context of a rainfall manipulation experiment in piñon-juniper woodland at the Sevilleta National Wildlife Refuge and LTER in central New Mexico, USA, sampling trees in irrigation (~150% ambient rainfall), drought (50% ambient), cover control (ambient rainfall with similar drought infrastructure) and ambient control plots.  To quantify tissue and shoot level hydraulic performances we measured sapwood area-specific (KS, kg•m-1•s-1•MPa-1) and leaf area-specific (KL, g•m-1•s-1•MPa-1) hydraulic conductivity in similar sized distal branches, and we calculated AS:AL (sapwood area to leaf area ratio) to compare shoot level allocation.

Samples collected at predawn and midday both exhibited significant trends between species and across treatments.  Between species, juniper possessed significantly higher KS compared to piñon in all plots except irrigation, and higher KL than piñon in all plots.  Across treatments, irrigated juniper exhibited higher KS and KL relative to ambient and droughted plants, while irrigated piñon exhibited higher KS relative to ambient, drought and cover control plants, and irrigated and ambient piñon had higher KL than droughted and cover control plants.  Junipers did not modify AS:AL across treatments, while irrigated piñon had significantly lower AS:AL compared to all other plots.  Thus, under current climatic conditions in the Sevilleta, piñon and juniper achieve similar shoot hydraulic performances, but through different strategies: juniper maximizes xylem conductivity, while piñon maximizes xylem supply to leaves.  If climate change in the Southwest results in increased aridity, piñon could be vulnerable to extirpation from its current distribution in lower elevation PJ woodlands, as juniper demonstrates superior hydraulic capability at both the tissue and shoot level under drought conditions.

 

Core Areas: 

Data set ID: 

255

Keywords: 

Methods: 

Shoot ΨW

One shoot from each target tree was harvested between 0430-0545h and between 1200-1400h, to get predawn and midday water potential (referred to hereafter as ΨPD and ΨMD, respectively). Samples were placed in plastic bags containing a small segment of moist paper towel to prevent further dessication, which were placed in coolers out of direct sunlight in the interim time between collection and processing (between 15-60 minutes). Water potential (ΨW) [u1]was measured using a pressure chamber (PMS, Corvallis, OR).

Stem Hydraulics

After ΨW was measured, shoots were placed in humid plastic bags and allowed to equilibrate for 24 hours in a refrigerator.  Shoots were then trimmed underwater to remove peripheral embolized tissue and inserted into a steady state flow meter to measure hydraulic conductivity, Kh, kg•m-1•s-1•MPa-1 (see Hudson et al. 2010 for a full explanation of method).  In brief, the steady state flowmeter operates on the Ohm’s Law analogy of hydraulic transport (Tyree 1997), and solves for Kh by knowing the pressure gradient and the flow rate of sap surrogate (20 mM KCl, Zwieniecki et al. 2001) through the flowmeter, and measuring the pressure drop across the sample stem segment.  Hydraulic conductivity was calculated as flow through the sample segment divided by the pressure gradient across the sample segment. Sapwood cross-sections and distal leaf areas were measured for each sample to normalize Kh at tissue level (KS, sapwood area specific hydraulic conductivity, kg•m-1•s-1•MPa-1) and shoot level (KL, leaf area specific hydraulic conductivity, g•m-1•s-1•MPa-1). AS:AL was calculated for each species by dividing each sample’s sapwood area by distal leaf area.


Instrumentation: 

Instrument Name: Pressure Chamber    

Manufacturer: PMS Instrument Company    

Model Number: 1505D    


Instrument Name:  Gage model pressure transducer (0-15 psig range)    

Manufacturer:  Omega Engineering, INC.

Model number: PX26-015GV

Developing an Understanding of Vegetation Change and Fluvial Carbon Fluxes in Semi-Arid Environments at the Sevilleta National Wildlife Refuge, New Mexico: Characterization Data

Abstract: 

Dryland environments are estimated to cover around 40% of the global land surface, and are home to approximately 2.4 billion people. Many of these areas have recently experienced extensive land degradation. This study focuses on semi-arid areas in the US Southwest, where degradation over the past 150 years has been characterized by the invasion of woody vegetation into areas previously dominated by grasslands. This vegetation change has been associated with increases in soil erosion and water quality problems, including the loss of key nutrients such as carbon from the soil to adjacent fluvial systems. Such loss of resources may impact heavily upon the amount of carbon that is lost as the land becomes more heavily degraded.

Therefore, understanding these vegetation transitions is significant both for sustainable land use and global biogeochemical cycling. This study uses an ecohydrological approach to develop an understanding of the relationship between structure and function across these transitions. This is done via the monitoring of rainfall-runoff events across instrumented runoff plots with different vegetation characteristics to investigate fluvial sediment fluxes during intense summer monsoon season rainfall events.

Data set ID: 

251

Core Areas: 

Additional Project roles: 

48

Keywords: 

Methods: 

Experimental design: 

Each study area consisted of a 10m wide, 30m long, downslope runoff plot, bound at the top and sides with aluminum flashing and fitted with water collecting guttering at the bottom so inputs and outputs could be quantified. The guttering fed water into a flume fixed into the ground at 4⁰ allowing water leaving the plot as runoff to be quantified.

The flumes were instrumented with a pump sampler to collect runoff samples leaving the plot and a bubbler module to measure discharge. In addition all runoff and associated sediment was collected in a covered stock tank (560 gallons for study area 1&2, 1000 gallons for study are 3). Rainfall onto the plot was measured using tipping-bucket rain gauges connected to the pump sampler. Following rainfall events all data was downloaded from the sampler using Flowlink v3.2 software.

Eroded sediment was collected from stock tank following rainfall events, coarse organic matter was removed via flotation, samples were oven dried at 60⁰C, weighed and sieved for particle size analysis using US. standard sieves at the Sevilleta LTER field station.

Setting up plots: 

Plots were selected on comparable planar slopes in areas believed to be representative of endmember vegetation habitats.  

Instrumentation: 

Instrument Name: Pump samplers fitted with bubbler modules

Manufacturer: ISCO

Model Number: Model 6700 pump samplers and attached model 730 bubbler modules

Instrument Name: Tipping-bucket rain gauges

Manufacturer: ISCO

Model Number: 674

Instrument Name: Flowlink software

Manufacturer: ISCO

Model Number: Version 3.2

Instrument Name: Sieve set and shaker

Manufacturer: unknown/various (from Sevilleta LTER field station)

Model Number: US. Standard: 12mm, 4mm, 2mm, 1mm, 0.5mm, 0.063mm

Additional information: 

This data was collected and analyzed by Alan Puttock as part of the PhD project: ‘Developing an understanding of vegetation change and fluvial carbon fluxes in semi-arid environments’. This project is supervised by Dr Richard Brazier, Dr Jenifer Dungait and Dr Kit Macleod. Analysis of samples/data is being carried out at the University of Exeter and North Wyke Research, United Kingdom.

This data was collected under USFWS permit number: 22522 10-026


Study Area 1:  
Study Area Name: Grass Endmember Plot
Study Area Location: Five Points Grass core site (exact point location of plot provided below)
Single Point:  
North Coordinate: 34.339186     
West Coordinate: -106.728303
Study Area 2:  
Study Area Name: Creosote Endmember plot
Study Area Location: Five Points Creosote core site (exact point location of plot provided below)
Single Point:  
North Coordinate: 34.338443
West Coordinate: -106.738020
Study Area 3:  
Study Area Name: Piñon-Juniper Endmember Plot
Study Area Location: Cerro Montoso core site (exact point location of plot provided below)
Single Point:  
North Coordinate: 34.231197
West Coordinate: -106.313741

Developing an Understanding of Vegetation Change and Fluvial Carbon Fluxes in Semi-Arid Environments at the Sevilleta National Wildlife Refuge, New Mexico: Rainfall Runoff Events

Abstract: 

Dryland environments are estimated to cover around 40% of the global land surface, and are home to approximately 2.4 billion people. Many of these areas have recently experienced extensive land degradation. This study focuses on semi-arid areas in the US Southwest, where degradation over the past 150 years has been characterized by the invasion of woody vegetation into areas previously dominated by grasslands. This vegetation change has been associated with increases in soil erosion and water quality problems, including the loss of key nutrients such as carbon from the soil to adjacent fluvial systems. Such loss of resources may impact heavily upon the amount of carbon that is lost as the land becomes more heavily degraded.

Therefore, understanding these vegetation transitions is significant both for sustainable land use and global biogeochemical cycling. This study uses an ecohydrological approach to develop an understanding of the relationship between structure and function across these transitions. This is done via the monitoring of rainfall-runoff events across instrumented runoff plots with different vegetation characteristics to investigate fluvial sediment fluxes during intense summer monsoon season rainfall events.

Data set ID: 

247

Core Areas: 

Additional Project roles: 

47

Keywords: 

Methods: 

Experimental design: 

Each study area consisted of a 10m wide, 30m long, downslope runoff plot, bound at the top and sides with aluminum flashing and fitted with water collecting guttering at the bottom so inputs and outputs could be quantified. The guttering fed water into a flume fixed into the ground at 4⁰ allowing water leaving the plot as runoff to be quantified.

The flumes were instrumented with a pump sampler to collect runoff samples leaving the plot and a bubbler module to measure discharge. In addition all runoff and associated sediment was collected in a covered stock tank (560 gallons for study area 1&2, 1000 gallons for study are 3). Rainfall onto the plot was measured using tipping-bucket rain gauges connected to the pump sampler. Following rainfall events all data was downloaded from the sampler using Flowlink v3.2 software.

Eroded sediment was collected from stock tank following rainfall events, coarse organic matter was removed via flotation, samples were oven dried at 60⁰C, weighed and sieved for particle size analysis using US. standard sieves at the Sevilleta LTER field station.

Setting up plots: 

Plots were selected on comparable planar slopes in areas believed to be representative of endmember vegetation habitats.  

Instrumentation: 

Instrument Name: Pump samplers fitted with bubbler modules

Manufacturer: ISCO

Model Number: Model 6700 pump samplers and attached model 730 bubbler modules

Instrument Name: Tipping-bucket rain gauges

Manufacturer: ISCO

Model Number: 674

Instrument Name: Flowlink software

Manufacturer: ISCO

Model Number: Version 3.2

Instrument Name: Sieve set and shaker

Manufacturer: unknown/various (from Sevilleta LTER field station)

Model Number: US. Standard: 12mm, 4mm, 2mm, 1mm, 0.5mm, 0.063mm

Additional information: 

This data was collected and analyzed by Alan Puttock as part of the PhD project: ‘Developing an understanding of vegetation change and fluvial carbon fluxes in semi-arid environments’. This project is supervised by Dr Richard Brazier, Dr Jenifer Dungait and Dr Kit Macleod. Analysis of samples/data is being carried out at the University of Exeter and North Wyke Research, United Kingdom.

This data was collected under USFWS permit number: 22522 10-026

Study Area 1:  
Study Area Name: Grass Endmember Plot
Study Area Location: Five Points Grass core site (exact point location of plot provided below)
Single Point:  
North Coordinate: 34.339186     
West Coordinate: -106.728303
Study Area 2:  
Study Area Name: Creosote Endmember plot
Study Area Location: Five Points Creosote core site (exact point location of plot provided below)
Single Point:  
North Coordinate: 34.338443
West Coordinate: -106.738020 
Study Area 3:  
Study Area Name: Piñon-Juniper Endmember Plot
Study Area Location: Cerro Montoso core site (exact point location of plot provided below)
Single Point:  
North Coordinate: 34.231197
West Coordinate: -106.313741

Biome Transition Along Elevational Gradients in New Mexico (SEON) AmeriFlux Data (ongoing since 2007)

Abstract: 

The varied topography and large elevation gradients that characterize the arid and semi-arid Southwest create a wide range of climatic conditions - and associated biomes - within relatively short distances. This creates an ideal experimental system in which to study the effects of climate on ecosystems. Such studies are critical givien that the Southwestern U.S. has already experienced changes in climate that have altered precipitation patterns (Mote et al. 2005), and stands to experience dramatic climate change in the coming decades (Seager et al. 2007; Ting et al. 2007). Climate models currently predict an imminent transition to a warmer, more arid climate in the Southwest (Seager et al. 2007; Ting et al. 2007). Thus, high elevation ecosystems, which currently experience relatively cool and mesic climates, will likely resemble their lower elevation counterparts, which experience a hotter and drier climate. In order to predict regional changes in carbon storage, hydrologic partitioning and water resources in response to these potential shifts, it is critical to understand how both temperature and soil moisture affect processes such as evaportranspiration (ET), total carbon uptake through gross primary production (GPP), ecosystem respiration (Reco), and net ecosystem exchange of carbon, water and energy across elevational gradients.

We are using a sequence of six widespread biomes along an elevational gradient in New Mexico -- ranging from hot, arid ecosystems at low elevations to cool, mesic ecosystems at high elevation to test specific hypotheses related to how climatic controls over ecosystem processes change across this gradient. We have an eddy covariance tower and associated meteorological instruments in each biome which we are using to directly measure the exchange of carbon, water and energy between the ecosystem and the atmosphere. This gradient offers us a unique opportunity to test the interactive effects of temperature and soil moisture on ecosystem processes, as temperature decreases and soil moisture increases markedly along the gradient and varies through time within sites.

Data for this project can be found on the website:  http://ameriflux.ornl.gov/

Additional Project roles: 

302

Core Areas: 

Data set ID: 

254

Keywords: 

Data sources: 

sev254_sevameriflux_20131211.csv

Methods: 

Data collection follows Ameriflux protocols.  

Piñon Pine (Pinus edulis) Responses of Annual Growth to Water Availability in a Pinyon-Juniper Forest at the Sevilleta National Wildlife Refuge, New Mexico

Abstract: 

Increased incidence of large-scale forest die-off attributed to drought has been observed globally over the past decade, raising concern about the future stability of forests as carbon sinks.  To understand the mechanistic basis of semi-arid woodland responses to drought, we measured annual increment growth from branches of Pinus edulis in a rainfall manipulation experiment at the Sevilleta National Wildlife Refuge and LTER site in central New Mexico, USA. We collected 4 branches from each of five trees growing in drought, irrigation, cover control, and ambient control plots at a site in the Los Pinos Mountains.  We measured annual branch elongation, stem diameter, sapwood area, and leaf area.  We compared these structural data to fluctuations in annual precipitation across treatments to understand how such variation in available water influence branch growth.  Rainfall manipulation produced clear differences among treatment groups, with drought trees exhibiting shorter stem lengths, decreased stem and sapwood diameters, and decreased leaf area production than control treatments.  Irrigated trees displayed increased stem length, stem diameter, sapwood diameter, and leaf area production relative to ambient controls.  The net effect of these responses is a likely shift in the allometric relationships, such as hydroactive xylem and absorbing root area.

Additional Project roles: 

18
19
20

Data set ID: 

248

Core Areas: 

Keywords: 

Methods: 

Branch sampling, four small branches were removed from each of five target trees per plot according to aspect (North, South, East, West). 

Experimental design:  Single block from complete block design.

Plots:  Four plots of varying treatments (Irrigation, Drought, Cover control, Ambient control) were used from preexisting study, each 40m X 40m.

Sampling:  Samples taken according to aspect (North, South, East, West) on all pinon target trees within one replicate block.

Measurements:  Stem length, two perpendicular midpoint diameter, and two perpendicular sapwood diameters were taken for each growth increment for each sample using digital callipers. Needles from each age cohort were scanned and leaf area was estimated using ImageJ software.

Rio Grande Water Chemistry Data from Bernalillo County, New Mexico (2006-2007)

Abstract: 

Human populations in Colorado, New Mexico and Texas depend on the Rio Grande for municipal water, agricultural irrigation, and recreation. The Rio Grande and its riparian corridor also support thousands of species of plants, invertebrates and vertebrates, some of which include over 300 species of migratory birds and the endangered Rio Grande silvery minnow and southwestern willow flycatcher. Eutrophication and salinization are the two most important types of water quality degradation which negatively impact the human and nonhuman biological communities in this water poor region. In spite of their significance, few published studies have investigated anthropogenic and natural sources of nutrients and dissolved solids to the Rio Grande. This study investigated the patterns and trends of nutrients and dissolved solids in the Middle Rio Grande (MRG) on a monthly basis from September 2005 – January 2008. During all months, wastewater treatment plants were the major source of nutrients to the MRG. Under high flow conditions, nutrient levels remained elevated for 260 river kilometers below the wastewater inputs. During months when significant portions of the river flow were diverted for irrigation, nitrate and phosphate were removed from the MRG and concentrations at the downstream end of the reach were returned to levels comparable to the un-impacted northern reach of river. Dissolved solids were added to the river by both wastewater and saline tributary inputs. Both anthropogenic and natural inputs of dissolved solids were found to affect water quality in the MRG. Continuous real-time measurements of temperature, pH, turbidity, dissolved oxygen, and conductivity also were initiated at four sites above and through the urban reach of the City of Albuquerque. Preliminary results show increasing turbidity and dissolved oxygen depletions associated with storm runoff from urban areas. 

Data set ID: 

180

Additional Project roles: 

200
201

Core Areas: 

Keywords: 

Purpose: 

The objectives of this study were to: 1) conduct a detailed assessment of the temporal and spatial trends in water quality of the MRG, 2) determine sources of eutrophication and salinization along the MRG, 3) estimate instream nutrient processing and retention, 4) calculate the effects of urbanization on dissolved oxygen and stream metabolism values in the MRG, and 5) provide baseline data for future water-quality monitoring and assessment in the MRG. 

Methods: 

Experimental Design:  

Samples were collected along the lenth of the MRG over a two to three day period, approximately monthly. Single grab samples were collected at each site. During 'Monthly' collections samples were taken from just the mainstem of the MRG. During 'Synoptic' collections samples were taken from both the mainstem sites and all of the major tributaries to the MRG. Mainstem sites were located ~ 5 km downstream of each major tributary to  the MRG to allow complete mixing of the tributary and mainstem water bodies and tributaries were sampled just prior to their convergence with the mainstem of the Rio Grande. Samples were collected during periods of stable flow (samples were not collected during storm pulses). 

Field methods: 

Surface-water samples were collected for measurement of temperature, pH, and conductivity, and analysis of major dissolved inorganic nutrients (nitrate, phosphate, and ammonium), major cations (sodium, potassium, magnesium and calcium), major anions (sulfate, bromide and chloride), dissolved organic and inorganic carbon (DOC, DIC), specific ultraviolet absorbance (SUVA), and chlorophyll a at each site. Sampling began in September 2005 and continued through February 2008. All samples were collected as close to the stream thalweg as flows permitted. Water samples for analysis of nutrients, cations, and anions were collected as grab samples in 130 ml syringes and immediately filtered in the field through ashed 0.7 um pore size glass fiber filters. Unfiltered water samples for chlorophyll-a analysis were collected in acid washed or unused HDPE bottles. All samples were placed on ice and transported to the laboratory for analysis.

Laboratory Procedures:  

Ammonium samples were analyzed using the phenyl hypochlorite method and a 10 cm flow path modified from Hansen and Koroleff (Hansen and Koroleff 1983). Bromide, chloride, nitrate, phosphate and sulphate were analyzed by ion chromatography (Dionex, Standard Method EPA 300.1, 2).  Organic and inorganic carbon were analyzed using a Shimadzu TOC-5050A carbon analyzer using Standard Method 5310 B (Clesceri et al. 1998). Sodium, potassium, magnesium, and calcium were analyzed using a Perkin Elmer Optima 5300 DV ICP using Standard Method 3120 B (EPA 200.7) (Clesceri et al. 1998). Clesceri, L. S., A. E. Greenberg, and A. D. Eaton, editors. 1998. Standard Methods for the Examination of Water and Wastewater. 20 edition. American Public Health Association, American Water Works Association, Water Environment Federation, Baltimore. Hansen, H. P. and F. Koroleff. 1983. Determination of Nutrients. Pages 159-226 in K. Grasshoff, K. Kremling, and M. Ehrhardt, editors. Methods of Seawater Analysis. Weinheim: Verlag Chemie.

Data sources: 

sev180_waterchemistry_02282012.txt

Instrumentation: 

* Instrument Name: Carbon Analyzer

* Manufacturer: Shimadzu

* Model Number: TOC-5050A

* Instrument Name: Ion Chromatograph

* Manufacturer: Dionex

* Model Number: 

* Instrument Name: Inductively Coupled Plasma Optical Emission Spectrometer

* Manufacturer: Perkin Elmer

* Model Number: Optima 5300 DV ICP 

Rio Grande River Sonde Data from Bernalillo County, New Mexico (2006-2007)

Abstract: 

Human populations in Colorado, New Mexico and Texas depend on the Rio Grande for municipal water, agricultural irrigation, and recreation. The Rio Grande and its riparian corridor also support thousands of species of plants, invertebrates and vertebrates, some of which include over 300 species of migratory birds and the endangered Rio Grande silvery minnow and southwestern willow flycatcher. Eutrophication and salinization are the two most important types of water quality degradation which negatively impact the human and nonhuman biological communities in this water poor region. In spite of their significance, few published studies have investigated anthropogenic and natural sources of nutrients and dissolved solids to the Rio Grande. This study investigated the patterns and trends of nutrients and dissolved solids in the Middle Rio Grande (MRG) on a monthly basis from September 2005 – January 2008. During all months, wastewater treatment plants were the major source of nutrients to the MRG. Under high flow conditions, nutrient levels remained elevated for 260 river kilometers below the wastewater inputs. During months when significant portions of the river flow were diverted for irrigation, nitrate and phosphate were removed from the MRG and concentrations at the downstream end of the reach were returned to levels comparable to the un-impacted northern reach of river. Dissolved solids were added to the river by both wastewater and saline tributary inputs. Both anthropogenic and natural inputs of dissolved solids were found to affect water quality in the MRG. Continuous real-time measurements of temperature, pH, turbidity, dissolved oxygen, and conductivity also were initiated at four sites above and through the urban reach of the City of Albuquerque. Preliminary results show increasing turbidity and dissolved oxygen depletions associated with storm runoff from urban areas. 

Core Areas: 

Data set ID: 

190

Additional Project roles: 

268
269

Keywords: 

Purpose: 

The objectives of this study were to: 1) conduct a detailed assessment of the temporal and spatial trends in water quality of the MRG, 2) determine sources of eutrophication and salinization along the MRG, 3) estimate instream nutrient processing and retention, 4) calculate the effects of urbanization on dissolved oxygen and stream metabolism values in the MRG, and 5) provide baseline data for future water-quality monitoring and assessment in the MRG. 

Methods: 

Experimental Design:  

Four sites were chosen within the Albuquerque reach for continuous measurement of five water-quality field parameters; temperature, conductivity, pH, turbidity, and dissolved oxygen. Sites were chosen to provide instrument stability and a gradient of urban influence with the most northern site located above urban wastewater inputs and the southern site below the Bernalillo, Rio Rancho, and Albuquerque wastewater treatment plants. 

Sampling Design:

 Readings were collected every fifteen minutes. 

Field methods: 

Sondes were recalibrated in the field every two to four weeks following manufacturers specifications.

Data sources: 

sev190_rgsonde_20121022.txt

Instrumentation: 

* Instrument Name: Multi-Parameter Water Quality Sonde

* Manufacturer: Yellow Spring Instruments

* Model Number: YSI 6920 

Quality Assurance: 

This data has been visually inspected to: 1) identify outliers and periods when the units were buried by sediment or were not functioning properly, and 2) examine the data for consistency of individual observations with temporal and spatial trends seen at upstream and downstream units.

Additional information: 

Additional Site Information:

site_number,site_name,site,latitude,longitude,river_kilometer,rgtrib,IsSonde

48,Alameda_Drain,ALMDRAIN,35.20,-106.64,98.91,T,0

49,Albuqerque_Riverside_Drai,ABQRSDRN,34.95,-106.68,131.13,T,0

14,Albuqerque_WWTP,ABQCWWTP,35.02,-106.67,122.86,T,0

17,Atrisco_Drain,ATRSCDRN,34.95,-106.68,131.08,T,0

2,Bernalillo_WWTP,BERNWWTP,35.31,-106.56,81.90,T,0

12,Central_Bride_Drain,CENDRAIN,35.10,-106.69,112.51,T,0

45,Elephant_Butte,ELEBUTTE,33.15,-107.22,375.41,M,0

8,LCRDR,LCRDRAIN,35.16,-106.67,104.48,M,0

33,LFCC_at_NB_Gate_BD,LFCCNGBD,33.87,-106.85,267.50,T,0

32,LFCC_at_NCP,FCCLNCP,33.96,-106.85,257.65,T,0

35,LFCC_at_SB_Gate_BD,LFCCSGBD,33.72,-106.91,287.09,T,0

44,LFCC_at_ST_PK_Gate,LFCCSTPK,33.63,-107.00,304.64,T,0

19,LL_WWTP,LOSLWWTP,34.78,-106.73,152.10,T,0

23,LPDR1,LPDR1DRN,34.66,-106.74,166.92,T,0

25,LPDR2,LPDR2DRN,34.59,-106.75,175.02,T,0

28,L_&_J_Drain,LNJDRAIN,34.37,-106.84,203.48,T,0

10,Oxbow_Drain,OXBDRAIN,35.14,-106.69,107.70,T,0

21,Peralta,Wasteway,PERALTWW,34.69,-106.74,162.83,T,0

41,RG_Above_Isleta_(I_25),RGABVISL,34.95,-106.68,131.11,M,1

7,RG_Alameda,RGALAMED,35.16,-106.67,104.46,M,0

40,RG_Angostura,RGANGOST,35.38,-106.50,70.84,M,0

13,RG_at_Central_Br,RGCENTBR,35.09,-106.68,113.59,M,0

9,RG_at_LCRDR,RGLCRDR,35.13,-106.69,107.81,M,0

42,RG_at_NCP,RGATNCP,33.96,-106.85,257.87,M,0

11,RG_at_Oxbow,RGOXBOW,35.11,-106.69,111.10,M,0

46,RG_at_Rio_Bravo,RGRIOBRV,35.03,-106.67,121.82,M,1

43,RG_at_Shirk,RGATSHRK,0.00,0.00,128.00,M,0

37,RG_at_ST_PK_Gate,RGSTPKGT,33.58,-107.06,312.87,M,0

24,RG_Belen_Bridge,RGBLENBR,34.59,-106.75,175.02,M,0

26,RG_Belen_Tower_Site,RGBLENTW,34.55,-106.76,180.91,M,0

15,RG_Below_ABQ_WWT,RGABQWWT,0.00,0.00,125.00,M,0

3,RG_Below_Bernalillo_WWTP,RGBERLWW,35.28,-106.60,86.65,M,0

18,RG_Below_Isleta,RGBELISL,34.87,-106.72,141.95,M,0

20,RG_Below_LL_WWTP,RGLLWWTP,34.69,-106.74,162.70,M,0

22,RG_Below_Peralta,RGBLPERT,0.00,0.00,162.50,M,0

5,RG_Below_RR_WWTP,RGRRWWTP,35.20,-106.64,99.13,M,1

30,RG_Below_San_F,RGBLSANF,34.31,-106.85,211.14,M,0

1,RG_Bernalillo_550,RGBER550,35.32,-106.56,80.29,M,1

39,RG_Buckman,RGBUCKMN,35.84,-106.16,0.00,M,0

47,RG_LL_Bridge,RGLLBRDG,34.81,-106.72,148.97,M,0

34,RG_NB_GATE_BD,RGNBGTBD,33.87,-106.85,267.55,M,0

31,RG_San_Acacia,RGACACIA,34.26,-106.89,220.86,M,0

36,RG_SB_GATE_BD,RGSBGTBD,33.72,-106.91,287.23,M,0

29,Rio_Puerco,RIOPUERC,34.41,-106.85,201.73,T,0

4,Rio_Rancho_WWTP,RIORWWTP,35.26,-106.60,89.02,T,0

38,Rock_House,ROCKHOUS,33.38,-107.16,338.72,M,0

27,SanFrancisco_Drain,SFRANDRN,34.37,-106.84,203.33,T,0

50,Unit_7_Drain,UNITSVDR,34.26,-106.89,220.74,T,0

Hydraulic Constraints on Two Life History Stages of Larrea tridentata in a Chihuahuan Desert Creosote Shrubland at the Sevilleta National Wildlife Refuge, New Mexico (2002-2003)

Abstract: 

Maintaining high rates of water loss during times of high resource availability could allow establishing woody desert perennials to grow quickly by allowing them to take advantage of the fleeting but abundant monsoonal moisture typical of warm deserts like the Chihuahuan. However, a plant cannot endlessly increase water loss in order to grow faster --there are hydraulic constraints on rates of water loss. The hydraulic properties of each particular plant xylem and soil microsite, as well as the AR:AL absorbing root area to transpiring leaf area ratio) interact to set limits on rates of water loss. If transpiration rates become too high, cavitation may limit the ability of the xylem to supply water to the leaves. The main objective of this study was to test two hypotheses on a population of Larrea tridentata at the Sevilleta LTER in central New Mexico (1) do small plants grow faster and use water less conservatively than large, and (2) are there differences in the hydraulic constraints on small and large plants. Measurements were made every six weeks in the spring, summer and fall from April 2002 - August 2003. Field measurements of shoot growth, gas exchange and plant and soil water potentials were made to determine growth rates and water use. Measurements of leaf specific conductance determined the ability of the xylem to supply water to the leaves. Excavation findings were used to estimate (AR:AL). Xylem vulnerability curves and soil texture analysis were used to determine the hydraulic properties of the plant xylem and soil. A model determined where the limiting conductance occurred in the plant-soil continuum.

Data set ID: 

154

Core Areas: 

Additional Project roles: 

306
307

Keywords: 

Methods: 

Field Methods:

For gas exchange measurements a LiCor 6400 portable gas exchange system was used. Measurements took place in June, August and September 2002 and May, June, and August 2003. Two measurements were made on each plant at approximately 7-9:30AM and 10-12:30PM. One branch tip was chosen and marked on each 10 small and 10 large plants. The same branch tip was used for measurement throughout the day unless it broke, at which time another branch tip was chosen and marked. Stomatal Ratio was set to one because stomates are present on both sides of the leaf in this species. Because of the small size of the leaves, an energy balance approach was used to calculate the leaf temperature in the chamber.

Chamber temperature and humidity were controlled at ambient and reference CO2 was set to 400ppm. Using natural light plants were clamped into the chamber, oriented in their original direction, chamber conditions were allowed to stabilize. Leaf area was set to one during measurement. Because of the small leaves of the species, a branch tip had to be measured. Measured branch tips were cut and returned to the lab where their leaf area was measured.

A Vista Scan Scanner was used to create an image of the leaves. The bitmap image was then analyzed for number of pixels using Scion Image. A regression equation was developed which converted pixel number into leaf area in cm2.The gas exchange data was then recalculated to adjust for leaf area.

For plant water potential a Scholander Pressure bomb was used to measure branched stem tips consisting of 15-20 leaves and a woody base. Predawn water potential samples were collected between 4AM and 5AM. Midday water potentials were collected between 11AM and 1PM. Samples were placed into a plastic baggie with a moist paper towel during transport. Samples were collected in May, June, August, September and December 2002 as well as January, March, May, June and August 2003.

For whole plant hydraulic conductance measurements large sections of the xylem were measured using a vacuum canister to generate known vacuum pressures. The plant was attached to a water filled container on a balance via tiagon tubing. Changes in weight on the balance, and thus flow rate (mg/s) through the plant were measured by a computer using a program written in Turbo Pascal. Each sample was measured at four or five pressures and the change in flow rate with pressure was calculated as the total hydraulic conductance of all tissues contained in the sample. All samples were immediately placed into a plastic bag with a wet paper towel and transported to the lab where they were measured within 48 hours of collection.

For large plants an entire stem of the plant was cut at the base. The stems were cut under water at the lab, to about 30cm. For small plants the entire plant was excavated, and any roots larger than about 2mm in diameter were kept intact. Back at the lab, most of the root system was cut off under water, leaving the root collar and the initial un-branched portion of the main root which obviously supplied the entire plant. For both sizes, all green material was removed from the tips of the branches, leaving only woody stems.

The green portion of the plant included all leaves and sometimes large (up to 150mm) branched sections. For root hydraulic conductance measurements root segments +AD4-50cm were cut in the field and transported to the lab wrapped tightly in 3 plastic bags containing wet paper towel. Segments were re-cut underwater and the ends shaved off with a razor blade. They were then placed on a manifold and flow through the segment was measured. Segments were then flushed for 15 minutes with distilled water at 100kPa. Flow was then re-measured. Percent loss of conductivity is calculated as the difference between pre and post flush flow divided by post flush flow and multiplied by 100. Due to time constraints only one flush was performed on each sample. For soil water potential monitoring soil thermocouple psychrometers were placed under 4 large and 4 small plants at 30cm and 45cm below the soil surface. Measurements were made at or around 2AM when temperature gradients were at a minimum. A Campbell datalogger reported millivolt output which was converted to MPa using calibrations determined in the lab. Calibration involved regression of millivolt output against solutions of known salt concentration for each psychrometer.

Data sources: 

sev154_waterpot_07132009

Additional information: 

Additional Information on the personnel associated with the Data Collection / Data Processing Joy Francis, a post-doc with Jim Gosz, was instrumental in setting up this study.

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