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. Monoliti suolo Raccogliere da utilizzare come un peso lisimetri <ol><li> Costruire scatole d&#39;acciaio a tempo indeterminato 1 x 1 m quadrati di 1,5 metri di profondità da 8 millimetri in acciaio di spessore. </li><li> Premere le caselle aperte verticalmente nel terreno, con presse idrauliche montate su ancoraggi ad elica forato 3 metri di profondità nel terreno. </li><li> Scavare il monolito incassato utilizzando un escavatore o di apparecchiature simili. </li><li> Inserire uno stoppino in fibra di vetro in contatto con il suolo alla base del monolito. Passare lo stoppino attraverso la base di acciaio in un serbatoio 10 L per drenare il monolito, e poi saldare la base di acciaio sul fondo della scatola. </li><li> Uccidi vegetazione esistente sui monoliti applicando un erbicida non residua, come glifosato. </li></ol> 2. Stabilire comunità vegetali su monoliti del suolo <ol><li> Pianta i monoliti con otto piantine ciascuna di sette specie di Tallgrass Prairie erbe e forbs, per una densità totale di 56 piante per m 2. <ol><li&gt; Vegetali i seguenti Erbe: Bouteloua curtipendula (grama laterale avena), Schizachyrium scoparium (poco bluestem), nutans Sorghastrum (Indiangrass), Tridens albescens (tridens bianchi)]. </li><li> Pianta i seguenti forbs: azurea Salvia (lanciatore salvia), Solidago canadensis (Canada verga d&#39;oro), Desmanthus illinoensis (Illinois bundleflower, un legume). </li></ol></li><li> Piantine di piante in un design quadrato latino, ri-randomizzati per ciascun monolite. </li><li> Annaffiare le trapianti per circa 2 mesi dopo la semina. L&#39;obiettivo è quello di ridurre al minimo lo stress idrico durante la definizione iniziale. Utilizzare qualsiasi metodo conveniente come una bacchetta a mano o spruzzatore del giardino. La frequenza di irrigazione dipende clima e sulle previsioni meteo, in particolare la presenza di precipitazioni ambiente. </li><li> Dopo la fase iniziale establishment trapianto, mantenere i trapianti sotto precipitazioni ambiente per il tempo necessario, mentre le camere (Sezione3) sono costruiti. Rimuovere specie indesiderate che emergono nei monoliti durante istituzione, da parte a mano diserbo. </li></ol> 3. Camera design <ol><li> Costruire due camere ogni 1,2 m di larghezza, 1,5 m di altezza e 60 m di lunghezza, diviso in dieci sezioni lunghe 5 m. Costruire sezioni da pesante acciaio di dimensioni 5 mx 1,2 mx 1,6 m di profondità, sepolto a 1,5 m. <ol><li> Installare quattro monoliti in ogni sezione, due monoliti ciascuno dei due tipi di suolo, in ordine casuale. Installare ogni monolite in cima ad una capacità di 4.540 kg equilibrio. </li><li> Includere monoliti Bastsil nelle abbinamenti nelle sezioni pari. </li></ol></li><li> Unitevi sezioni adiacenti in superficie con 1 m di lunghezza x 1 m di larghezza x 0,3 m condotto lamiera alto per fornire un percorso per il flusso d&#39;aria. <ol><li> Alimentazione refrigerante a 10 ° C da una unità di refrigerazione 161,4 kW ad una serpentina di raffreddamento all&#39;interno di ogni canale. </li><li> Racchiudere la vegetazione con pellicola trasparente serra (spessore 0,006 &quot;/. 15 mm), come ad esempio utilizzato in altriesperimenti di manipolazione climatica 23. </li><li> Montare ogni coperchio con apertura zip sostenuta da un progetto di falda per consentire l&#39;accesso ai monoliti di campionamento. </li><li> Rimuovere il polietilene copre al termine della stagione di crescita. </li></ol></li></ol> 4. CO 2 e Air misura di temperatura; Controllo della temperatura <ol><li> L&#39;ingresso e l&#39;uscita del campione C A su entrambe le camere ogni 2 minuti attraverso linee di campionamento aria filtrata situati all&#39;entrata e all&#39;uscita di superambient e subambient camere. Questi dati informano iniezione di CO 2 e ventilatore controllo della velocità. <ol><li> Esempio C A e tenore di vapore acqueo, e la temperatura dell&#39;aria misura (T A) all&#39;entrata e all&#39;uscita di ciascuna sezione 5 m ad intervalli di 20 min. </li><li> Misurare tutti i campioni di aria per il CO 2 e il contenuto di vapore acqueo in tempo reale utilizzando analizzatori di gas infrarossi secondo il protocollo del produttore. </li><li> Misurare T A all&#39;ingresso, punto medio, und uscita di ogni sezione con schermati termocoppie filo sottile. </li></ol></li><li> Regolare il flusso di refrigerante attraverso la serpentina di raffreddamento all&#39;ingresso di ogni sezione di mantenere una media costante (sezione centrale) T A da sezione a sezione vicino alla T ambiente A. </li><li> Posizionare un sensore di quantum di avere una visione chiara del cielo e misurare fotosintetica fotone densità di flusso secondo il protocollo del produttore. Livello di luce è un input per l&#39;algoritmo di controllo del ventilatore. </li></ol> 5. C Un&#39;applicazione Trattamento <ol><li> Giorno <ol><li> Mescolare anidride carbonica pura (CO 2) con aria ambiente in ingresso a 500 microlitri L -1 C A utilizzando un controllore di flusso di massa nel condotto di ingresso della gamba superambient. Vedere la Sezione 4 per C A misura dei particolari. </li><li> Advect l&#39;aria arricchita attraverso le camere utilizzano ventole all&#39;ingresso al punto 1 e nelle sezioni a valle. </li><li> Mantenere il desiderato uscita C A di 390 microlitri L -1 (aria ambiente) regolando la velocità della ventola. <ol><li> Aumentare la velocità del ventilatore, se l&#39;uscita C A è al di sotto del set point. Questo permette meno tempo per la pianta l&#39;assorbimento di CO 2, con conseguente uscita superiore C A. </li><li> Diminuire la velocità del ventilatore se uscita C A è al di sopra del set point. </li></ol></li><li> Utilizzare lo stesso approccio nella camera subambient tranne introdurre e il controllo dell&#39;aria ambiente per raggiungere l&#39;uscita C A di 250 microlitri L -1. </li></ol></li><li> Ore notturne <ol><li> Invertire la direzione del flusso d&#39;aria. </li><li> Iniettare CO 2 in fine di uscita diurna della camera superambient per ottenere 530 microlitri L -1 C A, ei tassi di controllo di avvezione di mantenere 640 microlitri L -1 all&#39;uscita notte (ingresso diurno. </li><li> Introdurre all&#39;aria libera a ~ 390 microlitri L -1 CO 2 in ingresso notturno(uscita di giorno) del tasso di avvezione da camera e di controllo subambient mantenere 530 microlitri L -1 all&#39;uscita notte. </li></ol></li></ol> 6. precipitazione Ingressi <ol><li> Applicare la quantità delle precipitazioni stagione di crescita media per ogni monolite. <ol><li> Fornire acqua ad ogni monolite da una fonte di acqua per uso domestico attraverso un sistema di irrigazione a goccia. Pianificare gli eventi di irrigazione e gli importi delle applicazioni per approssimare il modello di pioggia stagionale per la posizione esperimento. Il calendario esatto dipende dal clima locale. </li></ol></li><li> Controllare i tempi di applicazione con un data logger e misurare i volumi di applicazioni con misuratori di portata. </li></ol> 7. Campionamento <ol><li> Misura profili verticali di volumetrica contenuto idrico del suolo (vSWC) settimanale durante il periodo di CO 2 di controllo, con un calibro attenuazione di neutroni o altra sonda appropriata. <ol><li> Incrementi profilo consigliati sono 20 cm di profondità con incrementi di 1 m depth, e una 50 cm incremento inferiore a 1 m. </li></ol></li><li> Misura monolite fuori terra produttività primaria netta (ANPP) raccogliendo tutti in piedi biomassa epigea alla fine della stagione di crescita. <ol><li> Tutti biomassa epigea è stato rimosso ogni anno, quindi in piedi la biomassa rappresenta la produzione primaria corrente. </li><li> Ordina la biomassa campionato da specie e asciutto per massa costante e pesare. </li><li> Utilizzare biomassa delle singole specie di quantificare specie vegetali contributi al ANPP. </li></ol></li></ol>

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The authors have nothing to disclose.

L&#39;impianto LYCOG raggiunge il suo obiettivo operativo di mantenere un 250-500 microlitri L -1 gradiente continuo delle concentrazioni C A sulle comunità praterie sperimentali stabilite su tre tipi di suolo. La variazione C A è lineare nell&#39;intervallo prescritto. Temperatura dell&#39;aria aumenta all&#39;interno di ogni sezione, ma è stato azzerato dalle spire tra sezione di raffreddamento nella maggior parte delle sezioni. Come risultato, l&#39;obiettivo operativo di mantenere...

Concentrazione di anidride carbonica atmosferica (C A) ha recentemente aumentato passato 400 microlitri L -1 da circa 270 microlitri L -1 prima della rivoluzione industriale. C A si prevede che raggiungerà almeno 550 ml L -1 entro il 2100 1. Questo tasso di crescita supera qualsiasi modifica C A osservati nel corso degli ultimi 500.000 anni. Il tasso di cambiamento senza precedenti in C A solleva la possibilità di risposte non lineari o soglia degli ecosistemi ad accrescere C A. Più ecosistema scala C A esperimenti di arricchimento applica solo due trattamenti, un solo livello di arricchito C A e un controllo. Questi esperimenti hanno notevolmente ampliato la nostra comprensione degli impatti sugli ecosistemi di C A arricchimento. Tuttavia, un approccio alternativo che può rivelare la presenza di risposte dell&#39;ecosistema non lineari crescenti C A è studiare ecosistemi attraverso un intervallo continuo di subambient asuperambient C A. Subambient C A è difficile da mantenere in campo, ed è stato il più delle volte studiata utilizzando camere di crescita 2. Superambient C A è stata studiata utilizzando camere di crescita, aperto-camere superiori, e le tecniche di arricchimento senza aria 3, 4. C A arricchimento avviene attraverso paesaggi che contengono molti tipi di terreno. Suoli proprietà possono influenzare fortemente le risposte degli ecosistemi a C A arricchimento. Ad esempio, la struttura del terreno determina la ritenzione di acqua e nutrienti nel profilo del suolo 5, la loro disponibilità a piante 6, e la quantità e qualità di materia organica 7-9. La disponibilità di umidità del suolo è un mediatore cruciale della risposta degli ecosistemi alla C A di arricchimento nei sistemi idrici limitati, tra cui la maggior parte delle praterie 10. Campo Passato C A esperimenti di arricchimento sono in genere esaminato un solo tipo di terreno, e controllato prove di continuo vtipi arying C Un arricchimento su più suolo sono carenti. Se gli effetti di C A arricchimento sui processi ecosistemici differenziano il tipo di suolo, vi è una forte ragione di aspettarsi variazione spaziale nelle risposte degli ecosistemi a C Un arricchimento e cambiamenti conseguenti climatici 11, 12. Il biossido di carbonio lisimetro Gradient (LYCOG) impianto è stato progettato per rispondere alle domande di variazione spaziale nelle risposte non lineari e soglia degli ecosistemi a livelli C A che vanno da ~ 250 a 500 microlitri L -1. LYCOG crea il gradiente prescritto di C A sulle comunità vegetali praterie perenni che crescono su terreni che rappresentano la vasta gamma di texture, N e C, i contenuti e le proprietà idrologiche di praterie nella parte meridionale degli Stati Uniti Pianure Centrali. Serie terreni specifici utilizzati nella struttura sono di Houston nero argilla (32 monoliti), un Vertisol (udico Haplustert) tipico della pianura; Austin (32 monoliti), un alto carbonate, argilla limosa mollisol (Udorthentic Haplustol) tipico di altipiani; e Bastsil (16 monoliti), un alluvionali terriccio sabbioso Alfisol (udico Paleustalf). Il principio operativo impiegato in LYCOG è quello di sfruttare la capacità fotosintetica delle piante di esaurire C A da particelle d&#39;aria si muovevano direzionale attraverso le camere chiuse. L&#39;obiettivo di trattamento è mantenere una pendenza costante diurna lineare C A da 500 a 250 microlitri L -1. Per fare questo, LYCOG consiste di due camere lineari, una camera superambient mantenendo la porzione del gradiente da 500 al 390 (ambiente) microlitri L -1 C A, e una camera di subambient mantenendo il 390 al 250 microlitri L -1 porzione pendenza. Le due camere sono situate una accanto all&#39;altra, orientato su un asse nord-sud. Il C Un gradiente viene mantenuta durante la parte dell&#39;anno quando la capacità fotosintetica vegetazione è adeguata; tipicamente dafine aprile ai primi di novembre. Le camere contengono sensori e strumentazione necessari per regolare la C Un gradiente, il controllo della temperatura dell&#39;aria (T A) nei pressi di valori ambientali, e applicare importi precipitazione uniforme per tutti i terreni. I suoli sono monoliti intatte raccolti dalla vicina prateria Blackland installato in lisimetri pesatura idrologicamente isolate strumentati per determinare tutte le componenti del bilancio idrico. L&#39;acqua viene applicato a eventi di volume e tempistica che approssimano la stagionalità degli eventi di pioggia e ammonta nel corso di un anno medio di precipitazione. Così, LYCOG è in grado di valutare gli effetti a lungo termine di subambient per superambient C A e tipo di suolo sulla funzione degli ecosistemi prateria tra cui bilanci idrici e del carbonio. LYCOG è la terza generazione di C A esperimenti gradiente condotti da USDA ARS Grassland suolo e delle acque Research Laboratory. La prima generazione era un prototipo di subambientgradiente ambientale che ha stabilito la fattibilità dell&#39;approccio pendenza 13 e avanzato la nostra comprensione delle risposte fisiologiche a livello foglia di piante a subambient variazione C A 14-20. La seconda generazione è stato un campo di applicazione scala del concetto di perenne C 4 prati, con il gradiente esteso a 200-550 ml L -1 21. Questo esperimento campo scala fornito la prima evidenza che la produttività aumenta pascoli con C A arricchimento può saturare vicino concentrazioni nell&#39;ambiente attuali 20, in parte perché la disponibilità di azoto può limitare la produttività degli impianti a superambient C A 22. LYCOG estende questo esperimento di seconda generazione, incorporando terreni replicate di varia consistenza, permettendo robusta prova per effetti interattivi dei suoli sul C Una risposta delle comunità prateria.

<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

I continui aumenti delle concentrazioni atmosferiche di anidride carbonica (C A) tecniche di mandato per l&#39;esame impatti sugli ecosistemi terrestri. La maggior parte degli esperimenti di esaminare solo due o alcuni livelli di C Una concentrazione e un solo tipo di terreno, ma se C A può essere variata come un gradiente da subambient a superambient concentrazione su più terreni, siamo in grado di capire se le risposte degli ecosistemi ultimi possono continuare linearmente nel future e se le risposte possono variare attraverso il paesaggio. Il lisimetro Anidride carbonica gradiente strumento applica un 250-500 microlitri L -1 C Un gradiente di Blackland comunità vegetali prateria stabiliti lisimetri contenenti argilla, argilla limosa, e terreni sabbiosi. Il gradiente viene creato come la fotosintesi da vegetazione racchiusa in in camere a temperatura controllata esaurisce progressivamente l&#39;anidride carbonica dall&#39;aria che fluisce direzionale attraverso le camere. Mantenere una corretta portata d&#39;aria, adeguato photosycapacità di nthetic, e il controllo della temperatura sono fondamentali per superare le principali limitazioni del sistema, che sono in calo i tassi fotosintetici e aumento dello stress idrico durante l&#39;estate. La struttura è un&#39;alternativa economica ad altre tecniche di C A arricchimento, discerne con successo la forma delle risposte degli ecosistemi a subambient a superambient C A arricchimento, e può essere adattato per testare le interazioni di anidride carbonica con altri gas serra come il metano o l&#39;ozono.

I superambient e subambient porzioni del gradiente sono mantenute in camere separate (Figura 1). Tuttavia, in sette anni di funzionamento (2007 - 2013), le camere di mantenuto un gradiente lineare C Una concentrazione da 500 al 250 microlitri L -1 (Figura 2), con solo una piccola discontinuità C A tra l&#39;uscita delle camere arricchite (Monolith 40) e l&#39;ingresso della porzione subambient del gradiente (monolito 41). Te...

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

Il lisimetro Anidride carbonica gradiente strumento crea un 250-500 microlitri L -1 anidride carbonica sfumatura lineare nella comunità vegetali camere abitazioni prateria a temperatura controllata in argilla, argilla limosa, e monoliti di sabbia del suolo. L&#39;impianto viene utilizzato per determinare come i livelli di biossido di carbonio passati e futuri influenzano ciclo del carbonio pascoli.

A CO<sub&gt; 2</sub&gt; Gradiente di concentrazione strumento per il test di CO<sub&gt; 2</sub&gt; Arricchimento e del suolo Effetti sulla Prateria Ecosistema Funzione

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

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Environment

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

11.3K Views.  Grassland Soil and Water Research Laboratory.  Il lisimetro Anidride carbonica gradiente strumento crea un 250-500 microlitri L -1 anidride carbonica sfumatura lineare nella comunità vegetali camere abitazioni prateria a temperatura controllata in argilla, argilla limosa, e monoliti di sabbia del suolo. L'impianto viene utilizzato per determinare come i livelli di biossido di carbonio passati e futuri influenzano ciclo del carbonio pascoli. 

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.

Progettazione e funzionamento di un continuo<sup&gt; 13</sup&gt; C e<sup&gt; 15</sup&gt; N Etichettatura Camera di Uniform o differenziale, metaboliche e strutturali, Flora Isotope Labeling

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

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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.

Progettazione e Costruzione di un Research Facility deflusso urbano

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.

Misurazione di carbonio a base di contaminanti mineralizzazione Utilizzando combinata CO<sub&gt; 2</sub&gt; flusso e radiocarbonio analisi

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 protocollo per la raccolta e la costruzione del suolo lisimetri core

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.

Terreno lisimetro scavo per accoppiate idrologici, geochimiche e microbiologiche Investigations

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.

Misurazione della reologia del petrolio greggio in equilibrio con CO<sub&gt; 2</sub&gt; Presso le condizioni del serbatoio

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.

Misura e mappatura modelli di erosione e deposizione relazionati al suolo carbonato concentrazioni sotto gestione agricola

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.

Gli impatti di irrigazione delle acque reflue su conducibilità idraulica del suolo: accoppiata campo campionamento e determinazione in laboratorio della conducibilità idraulica satura

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.

Valutazione di Dryocosmus Kuriphilus-ha indotto il danno su 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 esperimento di compressione uniaxiale con CO2-Bearing Coal utilizzando un sistema di test di accoppiamento gas-solido con flusso-solido con un sistema di prova

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