We thank Anne Gibson, Katherine Jones, Chris Kolodziejczyk, Alicia Naranjo, Kyle Tiner, and numerous students and temporary technicians for operating the LYCOG facility, conducting sampling, and data processing. L.G.R. acknowledges USDA-NIFA (2010-65615-20632).

1. Los monolitos de suelos recogen para ser utilizado como un peso de lisímetros <ol><li> Construir cajas de acero abiertas 1 x 1 m cuadrados por 1,5 m de profundidad de 8 mm de acero de espesor. </li><li> Pulse las cajas abiertas verticalmente en el suelo, utilizando prensas hidráulicas montadas sobre anclajes helicoidales perforado 3 m de profundidad en el suelo. </li><li> Excavar el monolito revestido utilizando una retroexcavadora o un equipo similar. </li><li> Coloque una mecha de fibra de vidrio en contacto con el suelo en la base del monolito. Pasar la mecha a través de la base de acero a un depósito de 10 L para drenar el monolito, y luego soldar la base de acero en la parte inferior de la caja. </li><li> Matar la vegetación existente en los monolitos mediante la aplicación de un herbicida no residual, tal como glifosato. </li></ol> 2. Establecer las comunidades vegetales en los monolitos de suelo <ol><li> Planta de los monolitos con ocho plantas cada una de las siete especies de pastos altos de pradera de gramíneas y herbáceas, para una densidad total de 56 plantas por m2. <ol><li&gt; Planta de las siguientes Hierbas: bouteloua curtipendula (grama-avena lado), Schizachyrium scoparium (little bluestem), nutans Sorghastrum (Indiangrass), albescens Tridens (tridens blancas)]. </li><li> Planta las siguientes Forbs: azurea Salvia (salvia lanzador), Solidago canadensis (Canadá vara de oro), Desmanthus illinoensis (bundleflower Illinois, una leguminosa). </li></ol></li><li> Plántulas en un diseño cuadrado latino, re-asignados al azar para cada monolito. </li><li> Riegue los trasplantes de aproximadamente 2 meses después de la siembra. El objetivo es reducir al mínimo el estrés hídrico durante el establecimiento inicial. Use cualquier método conveniente tal como una varita mano o regadera del jardín. La frecuencia de riego depende de clima y el tiempo local, en particular la ocurrencia de precipitaciones ambiente. </li><li> Después de la fase inicial de establecimiento del trasplante, mantener los trasplantes menores de precipitaciones ambiente durante tanto tiempo como sea necesario, mientras que las cámaras (Sección3) se construyen. Retire las especies no deseadas que emergen en los monolitos durante el establecimiento de la mano-escarda. </li></ol> 3. Cámara Diseño <ol><li> Construir dos cámaras cada 1,2 m de ancho, 1,5 m de altura y 60 m de longitud, dividido en diez secciones largas 5 m. Construya secciones de pesada de acero de dimensiones 5 mx 1,2 mx 1,6 m de profundidad, enterrada a 1,5 m. <ol><li> Instale cuatro monolitos en cada sección, dos monolitos de cada uno de los dos de los tipos de suelo, en orden aleatorio. Instale cada monolito encima de un 4,540 kg equilibrio capacidad. </li><li> Incluya monolitos Bastsil en las parejas en las secciones pares. </li></ol></li><li> Únete secciones adyacentes sobre el suelo con un 1 m de largo x 1 m de ancho x 0,3 m de conductos de chapa de altura para proporcionar una vía para la circulación de aire. <ol><li> Suministro de refrigerante a 10 ° C a partir de una unidad de refrigeración 161,4 kW para un serpentín de enfriamiento dentro de cada conducto. </li><li> Incluya la vegetación con película transparente de efecto invernadero (espesor de 0.006 &quot;/. 15 mm), tal como se utiliza en otraexperimentos de manipulación del clima 23. </li><li> Coloque cada tapa con una abertura con cremallera respaldado por un proyecto de solapa para permitir el acceso a los monolitos para el muestreo. </li><li> Retire el polietileno cubre al final de la temporada de crecimiento. </li></ol></li></ol> 4. CO 2 y la temperatura del aire de medición; Control de temperatura <ol><li> Ejemplo de entrada y salida C A en ambas cámaras cada 2 minutos a través de líneas de muestreo de aire con filtro ubicado en la entrada y salida de superambient y subambientes cámaras. Estos datos informan inyección de CO 2 y el ventilador de control de velocidad. <ol><li> Muestra C A y contenido de vapor de agua, y la temperatura del aire medida (TA) en la entrada y salida de cada sección 5 m en intervalos de 20 minutos. </li><li> Mida todas las muestras de aire para CO 2 y vapor de agua contenido en tiempo real utilizando analizadores de gas infrarrojos según el protocolo del fabricante. </li><li> Mida T A en la entrada, el punto medio, und salida de cada sección con termopares de alambre fino blindados. </li></ol></li><li> Regular el flujo de refrigerante a través del serpentín de enfriamiento en la entrada de cada sección para mantener una media constante (sección media) T A de una sección a cerca de la ambiente T A. </li><li> Coloque un sensor cuántico de tener una vista despejada del cielo y medir la densidad de flujo de fotones fotosintéticos de acuerdo con el protocolo del fabricante. Nivel de luz es una entrada al algoritmo de control del ventilador. </li></ol> 5. C Una Aplicación de Tratamiento <ol><li> Tiempo de día <ol><li> Mezclar dióxido de carbono puro (CO 2) con el aire ambiente entrante a 500 l L -1 C A, utilizando un controlador de flujo másico en el conducto de entrada de la pierna superambient. Vea la Sección 4 para C A detalles de medición. </li><li> La advección del aire enriquecido a través de las cámaras que utilizan ventiladores soplantes en la entrada de la sección 1 y en las secciones posteriores. </li><li> METROantener la C la salida deseada A de 390 l L-1 (aire ambiente), ajustando la velocidad del ventilador. <ol><li> Aumentar la velocidad del ventilador si la salida C A está por debajo del punto de ajuste. Esto permite menos tiempo para la absorción de la planta de CO 2, lo que resulta en una mayor salida de C A. </li><li> Disminuya la velocidad del ventilador si la salida C A está por encima del punto de ajuste. </li></ol></li><li> Usa el mismo enfoque en la cámara subambiente excepto introducir aire y control ambiental para lograr la salida C A de 250 l L -1. </li></ol></li><li> Noche <ol><li> Invierta la dirección del flujo de aire. </li><li> Inyectar CO 2 en el extremo de salida durante el día de la cámara superambient para lograr 530 l L -1 C A, y las tasas de advección de control para mantener 640 l L-1 en la salida nocturna (entrada diurna. </li><li> Introducir aire ambiente en ~ 390 l L -1 CO 2 a la entrada de la noche(salida diurna) de la tasa de advección cámara subambiente y control para mantener 530 l L-1 en la salida nocturna. </li></ol></li></ol> 6. Precipitaciones Entradas <ol><li> Aplique la cantidad de lluvia temporada de crecimiento media a cada monolito. <ol><li> Suministro de agua a cada monolito de una fuente de agua para uso doméstico a través de un sistema de riego por goteo. Programe los eventos de riego y las cantidades de aplicación para aproximar el régimen de lluvias estacional para la ubicación experimento. El horario exacto depende del clima local. </li></ol></li><li> Control de tiempo de aplicación con un registrador de datos y medir los volúmenes de aplicación con caudalímetros. </li></ol> 7. Muestreo <ol><li> Medir perfiles verticales de volumétrica contenido de agua del suelo (vSWC) semanalmente durante el período de CO 2 de control, con un medidor de atenuación de neutrones u otra sonda apropiada. <ol><li> Incrementos perfil recomendados son incrementos de profundidad 20 cm a 1 m dePTH, y un incremento de 50 cm por debajo de un 1 m. </li></ol></li><li> Medida monolito sobre el suelo la productividad primaria neta (ANPP) por la recolección de toda la biomasa aérea de pie al final de la temporada de crecimiento. <ol><li> Toda la biomasa aérea se retira cada año, en consecuencia, la biomasa representa la producción primaria actual. </li><li> Ordene la biomasa muestreada por especie y secos a una masa constante, y pesar. </li><li> Utilice la biomasa de las especies individuales para cuantificar las especies vegetales contribuciones a la ANPP. </li></ol></li></ol>

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The authors have nothing to disclose.

La instalación LYCOG logra su objetivo operacional del mantenimiento de un 250 a 500 l L -1 gradiente continuo de las concentraciones de C A en las comunidades de pastizales experimentales establecidas en tres tipos de suelo. El cambio en C A es lineal en el intervalo prescrito. La temperatura del aire aumenta dentro de cada sección, pero se restableció por los serpentines de enfriamiento entre la sección en la mayoría de las secciones. Como resultado de ello, el objetivo operaciona...

La concentración de dióxido de carbono atmosférico (C A) ha aumentado recientemente pasado 400 l L -1 de aproximadamente 270 l -1 L antes de la Revolución Industrial. C A se prevé que alcance al menos 550 l L-1 para el año 2100 1. Esta tasa de crecimiento supera cualquier cambio C A observados en los últimos 500.000 años. La tasa de cambio sin precedentes en C Un plantea la posibilidad de respuestas no lineales o de umbral de los ecosistemas para el aumento de C A. La mayor parte de los ecosistemas a escala C A experimentos de enriquecimiento aplica sólo dos tratamientos, un solo nivel de enriquecimiento C A y un control. Estos experimentos se han ampliado enormemente nuestra comprensión de los impactos ambientales de C Un enriquecimiento. Sin embargo, un enfoque alternativo que puede revelar la presencia de las respuestas del ecosistema no lineales a la creciente C A es estudiar los ecosistemas a través de un rango continuo de subambiente asuperambient C A. Subambiente C A es difícil de mantener en el campo, y más a menudo se ha estudiado el uso de cámaras de crecimiento 2. Superambient C A se ha estudiado el uso de cámaras de crecimiento, descapotables cámaras y técnicas de enriquecimiento al aire libre 3, 4. C Un enriquecimiento se produce a través de paisajes que contienen muchos tipos de suelo. Suelos propiedades pueden afectar fuertemente las respuestas del ecosistema a C Un enriquecimiento. Por ejemplo, la textura del suelo determina la retención de agua y nutrientes en el perfil del suelo 5, su disponibilidad para las plantas 6, y la cantidad y la calidad de la materia orgánica 7-9. La disponibilidad de la humedad del suelo es un mediador crucial de la respuesta de los ecosistemas a C Un enriquecimiento en sistemas de agua limitada, incluyendo la mayoría de los pastizales 10. Pasado campo C A experimentos de enriquecimiento han examinado típicamente sólo un tipo de suelo, y controlado de forma continua pruebas vtipos arying C Un enriquecimiento sobre varios suelos son escasas. Si los efectos de C Un enriquecimiento en los procesos del ecosistema difieren en el tipo de suelo, hay una fuerte razón para esperar que la variación espacial de las respuestas de los ecosistemas a C Un enriquecimiento y consiguientes cambios en el clima 11, 12. El Dióxido de Carbono Lisímetro Gradiente (LYCOG) instalación fue diseñada para hacer frente a las cuestiones de la variación espacial en las respuestas no lineales y de umbral de los ecosistemas a los niveles C A que van desde ~ 250 a 500 l L -1. LYCOG crea el gradiente prescrito de C A en las comunidades de plantas de pastizales perennes que crecen en suelos que representan a la amplia gama de textura, contenido de N y C, y las propiedades hidrológicas de pastizales en la parte sur de los EE.UU. Llanos Centrales. Series de suelos específicos utilizados en la instalación son de arcilla Houston Negro (32 monolitos), un Vertisol (Udic Haplustert) típico de las tierras bajas; Austin (32 monolitos), un alto carbonate, arcilla limosa Mollisol (Udorthentic Haplustol) típica de las tierras altas; y Bastsil (16 monolitos), un aluvión franco arenoso Alfisol (Udic paleustalf). El principio operativo empleado en LYCOG es aprovechar la capacidad fotosintética de las plantas a agotar C A partir de parcelas de aire se movían direccionalmente a través de las cámaras cerradas. El objetivo del tratamiento es mantener un gradiente lineal constante durante el día en C A desde 500 a 250 l L -1. Para lograr esto, LYCOG consta de dos cámaras lineales, una cámara de superambient el mantenimiento de la porción de la gradiente desde 500 a 390 (ambiente) l L -1 C A, y una cámara de mantenimiento de la subambiente 390 a 250 l L -1 porción de la gradiente. Las dos cámaras están ubicadas al lado del otro, orientado sobre un eje norte-sur. El gradiente C A se mantiene durante la parte del año en la capacidad fotosintética vegetación es adecuada; típicamente desdefinales de abril hasta principios de noviembre. Las cámaras contienen sensores e instrumentación necesarias para regular el C Un gradiente, controlar la temperatura del aire (TA), cerca de los valores ambientales, y aplicar cantidades de precipitación uniformes para todos los suelos. Los suelos son monolitos intactas recogidos desde la cercana pradera Blackland instalada en lisímetros de pesada aislados hidrológicamente-instrumentados para determinar todos los componentes del balance hídrico. El agua se aplica en eventos de volumen y el momento de que la aproximación de la estacionalidad de las lluvias y asciende durante un año promedio precipitación. Por lo tanto, LYCOG es capaz de evaluar los efectos a largo plazo de subambiente a superambient C A y el tipo de suelo en función de los ecosistemas de pastizales, incluyendo los presupuestos de agua y carbono. LYCOG es la tercera generación de C un gradiente de experimentos llevados a cabo por el USDA ARS Pastizales del suelo y el Laboratorio de Investigación del Agua. La primera generación fue un prototipo para subambientegradiente ambiente que estableció la viabilidad del enfoque gradiente de 13 y se hace avanzar nuestra comprensión de las respuestas fisiológicas de nivel de hoja de las plantas para subambiente variación en C A de 14-20. La segunda generación fue una aplicación de campo a gran escala del concepto de perenne C 4 pastizales, con el gradiente extendido a 200-550 l L-1 21. Este experimento de campo a gran escala proporcionó la primera evidencia de que el aumento de la productividad de pastizales con C Un enriquecimiento de mayo saturar cerca de las concentraciones ambientales actuales 20, en parte debido a la disponibilidad de nitrógeno puede limitar la productividad vegetal en superambient C A 22. LYCOG extiende este segundo experimento generación incorporando suelos replicados de diferente textura, lo que permite la prueba robusta para efectos interactivos de los suelos en la C Una respuesta de las comunidades de pastizales.

<table>
	<tbody>
		<tr>
			<td>Dataloggers, multiplexers</td>
			<td>Campell Scientific, Logan, UT, USA</td>
			<td>CR-7, CR-10, CR-21X, SDM-A04, SDM-CD16AC, AM25T</td>
			<td></td>
		</tr>
		<tr>
			<td>Thermocouples: Copper-constantan</td>
			<td>Omega Engineering, Inc., Stamford, CT, USA</td>
			<td>TT-T-40-SLE, TT-T-24-SLE</td>
			<td></td>
		</tr>
		<tr>
			<td>Quantum sensor</td>
			<td>Li-Cor Biosciences, Lincoln, NE, USA</td>
			<td>LI-190SB</td>
			<td></td>
		</tr>
		<tr>
			<td>CO2/H2O analyzer</td>
			<td>Li-Cor Biosciences, Lincoln, NE, USA</td>
			<td>LI-7000</td>
			<td></td>
		</tr>
		<tr>
			<td>Lysimeter scales</td>
			<td>Avery Weigh-Tronix, Houston, TX, USA</td>
			<td>DSL-3636-10</td>
			<td></td>
		</tr>
		<tr>
			<td>Air sampling pump</td>
			<td>Grace Air Components, Houston, TX, USA</td>
			<td>VP 0660</td>
			<td></td>
		</tr>
		<tr>
			<td>Dew-point generator</td>
			<td>Li-Cor Biosciences, Lincoln, NE, USA</td>
			<td>LI-610</td>
			<td></td>
		</tr>
		<tr>
			<td>Cold water chiller</td>
			<td>AEC Application Engineering, Wood Dale, IL, USA</td>
			<td>CCOA-50</td>
			<td></td>
		</tr>
		<tr>
			<td>Chilled water flow control values</td>
			<td>Belimo Air Controls, Danbury, CT, USA</td>
			<td>LRB24-SR</td>
			<td></td>
		</tr>
		<tr>
			<td>Chilled-water cooling coils</td>
			<td>Coil Company, Paoli, PA, USA</td>
			<td>WC12-C14-329-SCA-R</td>
			<td></td>
		</tr>
		<tr>
			<td>Carbon dioxide refrigerated liquid</td>
			<td>Temple Welding Supply, Temple, TX, USA</td>
			<td>UN2187</td>
			<td></td>
		</tr>
		<tr>
			<td>Polyethylene film</td>
			<td>AT Plastics, Toronto, ON, Canada</td>
			<td>Dura-film Super Dura 4</td>
			<td></td>
		</tr>
		<tr>
			<td>Blower motor/controller</td>
			<td>Dayton Electric, Lake Forest, IL, USA</td>
			<td>2M168C/4Z829</td>
			<td></td>
		</tr>
		<tr>
			<td>Solenoids</td>
			<td>Industrial Automation, Cornelius, NC, USA</td>
			<td>U8256B046V-12/DC</td>
			<td></td>
		</tr>
		<tr>
			<td>Leachate collection pump</td>
			<td>Gast Manufacturing, Benton Harbor, MI, USA</td>
			<td>0523-V191Q-G588DX</td>
			<td></td>
		</tr>
	</tbody>
</table>

a co2 concentration gradient facility for testing co2 enrichment and soil effects on grassland ecosystem function

Continuando con los aumentos en las concentraciones de dióxido de carbono atmosférico (C A) técnicas de mandato para el examen de los impactos sobre los ecosistemas terrestres. La mayoría de los experimentos examinan sólo dos o unos pocos niveles de C Una concentración y un solo tipo de suelo, pero si C A se puede variar como un gradiente de subambiente a superambient concentraciones en varios suelos, podemos discernir si las respuestas del ecosistema últimos pueden continuar linealmente en la futuros y si las respuestas pueden variar a través del paisaje. El Fondo Degradado Dióxido de Carbono Lisímetro aplica un 250 a 500 l L -1 C Un gradiente de Blackland comunidades vegetales de las praderas establecidas en lisímetros que contienen arcilla, arcilla limosa y suelos arenosos. El gradiente se crea como la fotosíntesis de vegetación cerrada en en cámaras de temperatura controlada agota progresivamente dióxido de carbono del aire que fluye a través de las cámaras direccionalmente. El mantenimiento de la tasa de flujo de aire adecuado, photosy adecuadacapacidad nthetic, y control de temperatura son críticos para superar las principales limitaciones del sistema, que están disminuyendo las tasas de fotosíntesis y un mayor estrés hídrico durante el verano. La instalación es una alternativa económica a otras técnicas de C A enriquecimiento, discierne con éxito la forma de las respuestas del ecosistema a subambiente a superambient C Un enriquecimiento, y se puede adaptar para poner a prueba para las interacciones de dióxido de carbono con otros gases de efecto invernadero, tales como metano o el ozono.

Las porciones superambient y subambientes del gradiente se mantienen en cámaras separadas (Figura 1). Sin embargo, más de siete años de funcionamiento (2007 - 2013), las cámaras mantienen un gradiente lineal en C A de concentración desde 500 a 250 l L -1 (Figura 2) con sólo una pequeña discontinuidad en C A entre la salida de las cámaras enriquecidos (Monolith 40) y la entrada de la porción subambiente del gradiente (Monolith 41). <p class="...

Watch this Scientific Journal Video about A CO2 Concentration Gradient Facility for Testing CO2 Enrichment and Soil Effects on Grassland Ecosystem Function at JoVE.com

A CO2 Concentration Gradient Facility for Testing CO2 Enrichment and Soil Effects on Grassland Ecosystem Function

El Fondo Degradado Dióxido de Carbono Lisímetro crea un 250 a 500 l L -1 gradiente de dióxido de carbono lineal en las comunidades de plantas de pastizales cámaras vivienda de temperatura controlada en arcilla, arcilla limosa y monolitos de suelo arenoso. La instalación se utiliza para determinar cómo los niveles de dióxido de carbono del pasado y del futuro afectan el ciclo del carbono de los pastizales.

A CO<sub&gt; 2</sub&gt; Fondo gradiente de concentración para las pruebas de CO<sub&gt; 2</sub&gt; Enriquecimiento y suelo Efectos sobre la Función de los Ecosistemas del Prado

Continuing increases in atmospheric carbon dioxide concentrations (CA) mandate techniques for examining impacts on terrestrial ecosystems. Most ...

a-co2-concentration-gradient-facility-for-testing-co2-enrichment-soil

Research

JoVE Journal

Environment

A CO2 Concentration Gradient Facility for Testing CO2 Enrichment and Soil Effects on Grassland Ecosystem Function

11.3K vistas.  Grassland Soil and Water Research Laboratory.  El Fondo Degradado Dióxido de Carbono Lisímetro crea un 250 a 500 l L -1 gradiente de dióxido de carbono lineal en las comunidades de plantas de pastizales cámaras vivienda de temperatura controlada en arcilla, arcilla limosa y monolitos de suelo arenoso. La instalación se utiliza para determinar cómo los niveles de dióxido de carbono del pasado y del futuro afectan el ciclo del carbono de los pastizales. 

Video: A CO2 Concentration Gradient Facility for Testing CO2 Enrichment and Soil Effects on Grassland Ecosystem Function

Design and Operation of a Continuous 13C and 15N Labeling Chamber for Uniform or Differential, Metabolic and Structural, Plant Isotope Labeling

Tracing rare stable isotopes from plant material through the ecosystem provides the most sensitive information about ecosystem processes; from CO2 fluxes and soil organic matter formation to small-scale stable-isotope biomarker probing. Coupling multiple stable isotopes such as 13C with 15N, 18O or&#160;2H has the potential to reveal even more information about complex stoichiometric relationships during biogeochemical transformations. Isotope labeled plant material has been used in various studies of litter decomposition and soil organic matter formation1-4. From these and other studies, however, it has become apparent that structural components of plant material behave differently than metabolic components (i.e. leachable low molecular weight compounds) in terms of microbial utilization and long-term carbon storage5-7. The ability to study structural and metabolic components separately provides a powerful new tool for advancing the forefront of ecosystem biogeochemical studies. Here we describe a method for producing 13C and 15N labeled plant material that is either uniformly labeled throughout the plant or differentially labeled in structural and metabolic plant components.
Here, we present the construction and operation of a continuous 13C and 15N labeling chamber that can be modified to meet various research needs. Uniformly labeled plant material is produced by continuous labeling from seedling to harvest, while differential labeling is achieved by removing the growing plants from the chamber weeks prior to harvest. Representative results from growing Andropogon gerardii Kaw demonstrate the system&#39;s ability to efficiently label plant material at the targeted levels. Through this method we have produced plant material with a 4.4 atom%13C and 6.7 atom%15N uniform plant label, or material that is differentially labeled by up to 1.29 atom%13C and 0.56 atom%15N in its metabolic and structural components (hot water extractable and hot water residual components, respectively). Challenges lie in maintaining proper temperature, humidity, CO2 concentration,&#160;and light levels in an airtight 13C-CO2 atmosphere for successful plant production. This chamber description represents a useful research tool to effectively produce uniformly or differentially multi-isotope labeled plant material for use in experiments on ecosystem biogeochemical cycling.

Design and Operation of a Continuous 13C and 15N Labeling Chamber for Uniform or Differential, Metabolic and Structural, Plant Isotope Labeling

This method explains how to build and operate a continuous 13C and 15N isotope labeling chamber for uniform or differential plant tissue labeling. Representative results from metabolic and structural labeling of Andropogon gerardii are discussed.

Diseño y aplicación de un continuo<sup&gt; 13</sup&gt; C y<sup&gt; 15</sup&gt; N Cámara Etiquetado de Uniforme o Diferencial, metabólico y estructural, Planta de isótopos de etiquetado

Tracing rare stable isotopes from plant material through the ecosystem provides the most sensitive information about ecosystem processes; from CO2 fluxes ...

Investigación

Medio ambiente

Design and Construction of an Urban Runoff Research Facility

As the urban population increases, so does the area of irrigated urban landscape. Summer water use in urban areas can be 2-3x winter base line water use due to increased demand for landscape irrigation. Improper irrigation practices and large rainfall events can result in runoff from urban landscapes which has potential to carry nutrients and sediments into local streams and lakes where they may contribute to eutrophication. A 1,000 m2 facility was constructed which consists of 24 individual 33.6 m2 field plots, each equipped for measuring total runoff volumes with time and collection of runoff subsamples at selected intervals for quantification of chemical constituents in the runoff water from simulated urban landscapes. Runoff volumes from the first and second trials had coefficient of variability (CV) values of 38.2 and 28.7%, respectively. CV values for runoff pH, EC, and Na concentration for both trials were all under 10%. Concentrations of DOC, TDN, DON, PO4-P, K+, Mg2+, and Ca2+ had CV values less than 50% in both trials. Overall, the results of testing performed after sod installation at the facility indicated good uniformity between plots for runoff volumes and chemical constituents. The large plot size is sufficient to include much of the natural variability and therefore provides better simulation of urban landscape ecosystems.

This paper describes the design, construction, and function of a 1,000 m2 facility containing 24 individual 33.6 m2 field plots equipped for measuring total runoff volumes with time and collection of runoff subsamples at selected intervals for quantification of chemical constituents in the runoff water from simulated home lawns.

Diseño y Construcción de un Centro de Investigación La escorrentía urbana

As the urban population increases, so does the area of irrigated urban landscape. Summer water use in urban areas can be 2-3x winter base line water use ...

Measuring Carbon-based Contaminant Mineralization Using Combined CO2 Flux and Radiocarbon Analyses

A method is described which uses the absence of radiocarbon in industrial chemicals and fuels made from petroleum feedstocks which frequently contaminate the environment. This radiocarbon signal &#8212; or rather the absence of signal &#8212; is evenly distributed throughout a contaminant source pool (unlike an added tracer) and is not impacted by biological, chemical or physical processes (e.g., the 14C radioactive decay rate is immutable). If the fossil-derived contaminant is fully degraded to CO2, a harmless end-product, that CO2 will contain no radiocarbon. CO2 derived from natural organic matter (NOM) degradation will reflect the NOM radiocarbon content (usually &#60;30,000 years old). Given a known radiocarbon content for NOM (a site background), a two end-member mixing model can be used to determine the CO2 derived from a fossil source in a given soil gas or groundwater sample. Coupling the percent CO2 derived from the contaminant with the CO2 respiration rate provides an estimate for the total amount of contaminant degraded per unit time. Finally, determining a zone of influence (ZOI) representing the volume from which site CO2 is collected allows determining the contaminant degradation per unit time and volume. Along with estimates for total contaminant mass, this can ultimately be used to calculate time-to-remediate or otherwise used by site managers for decision-making.

Measuring Carbon-based Contaminant Mineralization Using Combined CO2 Flux and Radiocarbon Analyses

A protocol is described wherein CO2 mineralized from organic contaminant (derived from petroleum feedstocks) biodegradation is trapped, quantified, and analyzed for 14C content. A model is developed to determine CO2 capture zone's spatial extent. Spatial and temporal measurements allow integrating contaminant mineralization rates for predicting remediation extent and time.

La medición de contaminantes mineralización de base de carbono utilizando combinada CO<sub&gt; 2</sub&gt; flujo y análisis de radiocarbono

A method is described which uses the absence of radiocarbon in industrial chemicals and fuels made from petroleum feedstocks which frequently contaminate ...

A Protocol for Collecting and Constructing Soil Core Lysimeters

Leaching of nutrients from land applied fertilizers and manure used in agriculture can lead to accelerated eutrophication of surface water. Because the landscape has complex and varied soil morphology, an accompanying disparity in flow paths for leachate through the soil macropore and matrix structure is present. The rate of flow through these paths is further affected by antecedent soil moisture. Lysimeters are used to quantify flow rate, volume of water and concentration of nutrients leaching downward through soils. While many lysimeter designs exist, accurately determining the volume of water and mass balance of nutrients is best accomplished with bounded lysimeters that leave the natural soil structure intact. 
Here we present a detailed method for the extraction and construction of soil core lysimeters equipped with soil moisture sensors at 5 cm and 25 cm depths. Lysimeters from four different Coastal Plain soils (Bojac, Evesboro, Quindocqua and Sassafras) were collected on the Delmarva Peninsula and moved to an indoor climate controlled facility. Soils were irrigated once weekly with the equivalent of 2 cm of rainfall to draw down soil nitrate-N concentrations. At the end of the draw down period, poultry litter was applied (162 kg TN ha-1) and leaching was resumed for an additional five weeks. Total recovery of applied irrigation water varied from 71% to 85%. Nitrate-N concentration varied over the course of the study from an average of 27.1 mg L-1 before litter application to 40.3 mg L-1 following litter application. While greatest flux of nutrients was measured in soils dominated by coarse sand (Sassafras) the greatest immediate flux occurred from the finest textured soil with pronounced macropore development (Quindocqua).

A detailed method for extraction and assembly of intact soil core lysimeters and their use for study of leachate and associated loss of nutrients from surface applied poultry litter is demonstrated.

Un protocolo de recogida y la construcción de Lisímetros testigo del suelo

Leaching of nutrients from land applied fertilizers and manure used in agriculture can lead to accelerated eutrophication of surface water. Because the ...

Soil Lysimeter Excavation for Coupled Hydrological, Geochemical, and Microbiological Investigations

Studying co-evolution of hydrological and biogeochemical processes in the subsurface of natural landscapes can enhance the understanding of coupled Earth-system processes. Such knowledge is imperative in improving predictions of hydro-biogeochemical cycles, especially under climate change scenarios. We present an experimental method, designed to capture sub-surface heterogeneity of an initially homogeneous soil system. This method is based on destructive sampling of a soil lysimeter designed to simulate a small-scale hillslope. A weighing lysimeter of one cubic meter capacity was divided into sections (voxels) and was excavated layer-by-layer, with sub samples being collected from each voxel. The excavation procedure was aimed at detecting the incipient heterogeneity of the system by focusing on the spatial assessment of hydrological, geochemical, and microbiological properties of the soil. Representative results of a few physicochemical variables tested show the development of heterogeneity. Additional work to test interactions between hydrological, geochemical, and microbiological signatures is planned to interpret the observed patterns. Our study also demonstrates the possibility of carrying out similar excavations in order to observe and quantify different aspects of soil-development under varying environmental conditions and scale.

This study presents an excavation method for investigating subsurface hydrological, geochemical, and microbiological heterogeneity of a soil lysimeter. The lysimeter simulates an artificial hillslope which was initially under homogeneous condition and had been subjected to approximately 5,000 mm of water over eight cycles of irrigation in an 18-month period.

Lisímetro suelo de excavación para acoplados hidrológicos, geoquímicos, e investigaciones microbiológicas

Studying co-evolution of hydrological and biogeochemical processes in the subsurface of natural landscapes can enhance the understanding of coupled ...

Measurement of the Rheology of Crude Oil in Equilibrium with CO2 at Reservoir Conditions

A rheometer system to measure the rheology of crude oil in equilibrium with carbon dioxide (CO2) at high temperatures and pressures is described. The system comprises a high-pressure rheometer which is connected to a circulation loop. The rheometer has a rotational flow-through measurement cell with two alternative geometries: coaxial cylinder and double gap. The circulation loop contains a mixer, to bring the crude oil sample into equilibrium with CO2, and a gear pump that transports the mixture from the mixer to the rheometer and recycles it back to the mixer. The CO2 and crude oil are brought to equilibrium by stirring and circulation and the rheology of the saturated mixture is measured by the rheometer. The system is used to measure the rheological properties of Zuata crude oil (and its toluene dilution) in equilibrium with CO2 at elevated pressures up to 220 bar and a temperature of 50 &#176;C. The results show that CO2 addition changes the oil rheology significantly, initially reducing the viscosity as the CO2 pressure is increased and then increasing the viscosity above a threshold pressure. The non-Newtonian response of the crude is also seen to change with the addition of CO2.

Measurement of the Rheology of Crude Oil in Equilibrium with CO2 at Reservoir Conditions

A method for measuring the rheology of crude oil in equilibrium with carbon dioxide at reservoir conditions is presented.

Medición de la reología del petróleo crudo en equilibrio con CO<sub2</sub&gt; En las condiciones del yacimiento

A rheometer system to measure the rheology of crude oil in equilibrium with carbon dioxide (CO2) at high temperatures and pressures is described. The ...

Measuring and Mapping Patterns of Soil Erosion and Deposition Related to Soil Carbonate Concentrations Under Agricultural Management

Spatial patterns of soil erosion and deposition can be inferred from differences in ground elevation mapped at appropriate time increments. Such changes in elevation are related to changes in near-surface soil carbonate (CaCO3) profiles. The objective is to describe a simple conceptual model and detailed protocol for repeatable field and laboratory measurements of these quantities. Here, accurate elevation is measured using a ground-based differential global positioning system (GPS); other data acquisition methods could be applied to the same basic method. Soil samples are collected from prescribed depth intervals and analyzed in the lab using an efficient and precise modified pressure-calcimeter method for quantitative analysis of inorganic carbon concentration. Standard statistical methods are applied to point data, and representative results show significant correlations between changes in soil surface layer CaCO3 and changes in elevation consistent with the conceptual model; CaCO3 generally decreased in depositional areas and increased in erosional areas. Maps are derived from point measurements of elevation and soil CaCO3 to aid analyses. A map of erosional and depositional patterns at the study site, a rain-fed winter wheat field cropped in alternating wheat-fallow strips, shows the interacting effects of water and wind erosion affected by management and topography. Alternative sampling methods and depth intervals are discussed and recommended for future work relating soil erosion and deposition to soil CaCO3.

Spatial patterns of soil erosion and deposition can be inferred from differences in ground elevation mapped at appropriate time increments. Such changes in elevation are related to changes in near-surface soil carbonates. Repeatable methods for field and laboratory measurements of these quantities and data analysis methods are described here.

Medición y mapeo de patrones de erosión y deposición relacionadas las concentraciones de carbonato de suelo bajo manejo agrícola

Spatial patterns of soil erosion and deposition can be inferred from differences in ground elevation mapped at appropriate time increments. Such changes ...

Wastewater Irrigation Impacts on Soil Hydraulic Conductivity: Coupled Field Sampling and Laboratory Determination of Saturated Hydraulic Conductivity

Since the early 1960s, an alternative wastewater discharge practice at The Pennsylvania State University has been researched and its impacts monitored. Rather than discharging treated wastewater to a stream, and thereby directly impacting the stream quality, the effluent is applied to forested and cropped land managed by the University. Concerns related to reductions in soil hydraulic conductivity occur when considering wastewater reuse. The methodology described in this manuscript, matching soil sample size with the size of the laboratory-based hydraulic conductivity measurement apparatus, provides the benefits of a relatively rapid collection of samples with the benefits of controlled laboratory boundary conditions. The results suggest that there may have been some impact of wastewater reuse on the soil&#39;s ability to transmit water at deeper depths in the depressional areas of the site. Most of the reductions in the soil hydraulic conductivity in the depressions appear to be related to the depth from which the sample was collected, and by inference, associated with the soil structural and textural differences.

Here we present a methodology which matches a soil sample size and a hydraulic conductivity measurement device to prevent the so-called wall flow along the inside of the soil container from being erroneously included in water flow measurements. Its use is demonstrated with samples collected from a wastewater irrigation site.

Impactos de riego de aguas residuales en la conductividad hidráulica del suelo: unida los muestreo de campo y laboratorio determinación de la conductividad hidráulica saturada

Since the early 1960s, an alternative wastewater discharge practice at The Pennsylvania State University has been researched and its impacts monitored. ...

Evaluating Dryocosmus Kuriphilus-induced Damage on Castanea Sativa

Dryocosmus kuriphilus Yasumatsu has become a major pest for Castaneasativa since its arrival in Europe. Its galling activity results in the formation of different gall types and prevents the development of normal shoots. Repeated and uncontrolled attacks cause, besides the production of galls and the attendant gall-related reduction in leaf area, progressive corruption of the branch architecture, including the death of branch parts, and an increase in dormant bud activation. Thus far, there have been few attempts to quantify branch architecture damage. Further, the different methods for assessing infestation degree (MAID) that have been developed focus only on the galls' presence and abundance.
Using the leaf area to sapwood area relationship as a green biomass indicator, we developed in a previous study a damage composite index (DCI) that takes into account the most important branch architectural features, allowing for realistic damage assessment during the entire epidemic process. 
The aim of this study is to present this novel method and highlight differences in the damage description with respect to other broadly used indices. Results show how the DCI depicts branch damage better, especially during the epidemic peak, compared to MAID, which tend to underestimate it. We conclude by suggesting how to properly evaluate the overall impact of the pest by means of our composite damage index, the infestation degree using classic methods, and crown transparency evaluations.

Evaluating Dryocosmus Kuriphilus-induced Damage on Castanea Sativa

It is common practice to assess the damage caused by Dryocosmus kuriphilus by considering the abundance of galls alone rather than by also taking related branch corruption into consideration. We propose a composite damage index that takes into account the most important branch features, thus enabling more realistic damage assessment.

Evaluación de Dryocosmus Kuriphilus-inducida por daño en Castanea Sativa

Dryocosmus kuriphilus Yasumatsu has become a major pest for Castaneasativa since its arrival in Europe. Its galling activity results in the formation of ...

A Uniaxial Compression Experiment with CO2-Bearing Coal Using a Visualized and Constant-Volume Gas-Solid Coupling Test System

Injecting carbon dioxide (CO2) into a deep coal seam is of great significance for reducing the concentration of greenhouse gases in the atmosphere and increasing the recovery of coalbed methane. A visualized and constant-volume gas-solid coupling system is introduced here to investigate the influence of CO2 sorption on the physical and mechanical properties of coal. Being able to keep a constant volume and monitor the sample using a camera, this system offers the potential to improve instrument accuracy and analyze fracture evolution with a fractal geometry method. This paper provides all steps to perform a uniaxial compression experiment with a briquette sample in different CO2 pressures with the gas-solid coupling test system. A briquette, cold-pressed by raw coal and sodium humate cement, is loaded in high-pressure CO2, and its surface is monitored in real-time using a camera. However, the similarity between the briquette and the raw coal still needs improvement, and a flammable gas such as methane (CH4) cannot be injected for the test. The results show that CO2 sorption leads to peak strength and elastic modulus reduction of the briquette, and the fracture evolution of the briquette in a failure state indicates fractal characteristics. The strength, elastic modulus, and fractal dimension are all correlated with CO2 pressure but not with a linear correlation. The visualized and constant-volume gas-solid coupling test system can serve as a platform for experimental research about rock mechanics considering the multifield coupling effect.

A Uniaxial Compression Experiment with CO2-Bearing Coal Using a Visualized and Constant-Volume Gas-Solid Coupling Test System

This protocol demonstrates how to prepare a briquette sample and conduct a uniaxial compression experiment with a briquette in different CO2 pressures using a visualized and constant-volume gas-solid coupling test system. It also aims to investigate changes in terms of coal&#8217;s physical and mechanical properties induced by CO2 adsorption.

Un experimento de compresión uniaxial con carbón de CO2mediante un sistema de prueba de acoplamiento de gas sólido de volumen fijo y de volumen constante

Injecting carbon dioxide (CO2) into a deep coal seam is of great significance for reducing the concentration of greenhouse gases in the atmosphere and ...