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Spatial variability and application of ratios between BTEX in two Canadian cities	2011	Department of Civil and Environmental Engineering, University of Windsor, Windsor, ON, Canada N9B 3P4.	Read more...
Source Type Print(0) Ref Type Journal Article Periodical, Full TheScientificWorldJournal Periodical, Abbrev. ScientificWorldJournal Pub Date Free Form Volume 11 Issue Start Page 2536 Other Pages 2549 Notes LR: 20150128; JID: 101131163; 0 (Air Pollutants); 0 (Benzene Derivatives); 0 (Vehicle Emissions); 0 (Volatile Organic Compounds); 0 (Xylenes); 3FPU23BG52 (Toluene); J64922108F (Benzene); L5I45M5G0O (ethylbenzene); OID: NLM: PMC3253549; OTO: NOTNLM; 2011/1 Place of Publication England ISSN/ISBN 1537-744X; 1537-744X Accession Number PMID: 22235184 Language eng SubFile Comparative Study; Journal Article; Research Support, Non-U.S. Gov't; IM DOI 10.1100/2011/167973 [doi] Output Language Unknown(0) PMID 22235184 Abstract Spatial monitoring campaigns of volatile organic compounds were carried out in two similarly sized urban industrial cities, Windsor and Sarnia, ON, Canada. For Windsor, data were obtained for all four seasons at approximately 50 sites in each season (winter, spring, summer, and fall) over a three-year period (2004, 2005, and 2006) for a total of 12 sampling sessions. Sampling in Sarnia took place at 37 monitoring sites in fall 2005. In both cities, passive sampling was done using 3M 3500 organic vapor samplers. This paper characterizes benzene, toluene, ethylbenzene, o, and (m + p)-xylene (BTEX) concentrations and relationships among BTEX species in the two cities during the fall sampling periods. BTEX concentration levels and rank order among the species were similar between the two cities. In Sarnia, the relationships between the BTEX species varied depending on location. Correlation analysis between land use and concentration ratios showed a strong influence from local industries. Use one of the ratios between the BTEX species to diagnose photochemical age may be biased due to point source emissions, for example, 53 tonnes of benzene and 86 tonnes of toluene in Sarnia. However, considering multiple ratios leads to better conclusions regarding photochemical aging. Ratios obtained in the sampling campaigns showed significant deviation from those obtained at central monitoring stations, with less difference in the (m + p)/E ratio but better overall agreement in Windsor than in Sarnia. Descriptors Links Book Title Database Publisher Data Source Authors Miller,L., Xu,X., Wheeler,A., Atari,D.O., Grgicak-Mannion,A., Luginaah,I. Original/Translated Title URL Date of Electronic 20111229 PMCID PMC3253549 Editors
Spatial variability in levels of benzene, formaldehyde, and total benzene, toluene, ethylbenzene and xylenes in New York City: a land-use regression study	2012	New York City Department of Health and Mental Hygiene, Bureau of Environmental Surveillance and Policy, 125 Worth Street, CN34E, New York, NY 10013, USA. ikheirbe@health.nyc.gov	Read more...
Source Type Print(0) Ref Type Journal Article Periodical, Full Environmental health : a global access science source Periodical, Abbrev. Environ.Health Pub Date Free Form 31-Jul Volume 11 Issue Start Page 51 Other Pages 069X-11-51 Notes LR: 20150224; JID: 101147645; 0 (Air Pollutants); 0 (Benzene Derivatives); 1HG84L3525 (Formaldehyde); OID: NLM: PMC3420325; 2012/03/06 [received]; 2012/07/09 [accepted]; 2012/07/31 [aheadofprint]; epublish Place of Publication England ISSN/ISBN 1476-069X; 1476-069X Accession Number PMID: 22849853 Language eng SubFile Journal Article; Research Support, Non-U.S. Gov't; IM DOI 10.1186/1476-069X-11-51 [doi] Output Language Unknown(0) PMID 22849853 Abstract BACKGROUND: Hazardous air pollutant exposures are common in urban areas contributing to increased risk of cancer and other adverse health outcomes. While recent analyses indicate that New York City residents experience significantly higher cancer risks attributable to hazardous air pollutant exposures than the United States as a whole, limited data exist to assess intra-urban variability in air toxics exposures. METHODS: To assess intra-urban spatial variability in exposures to common hazardous air pollutants, street-level air sampling for volatile organic compounds and aldehydes was conducted at 70 sites throughout New York City during the spring of 2011. Land-use regression models were developed using a subset of 59 sites and validated against the remaining 11 sites to describe the relationship between concentrations of benzene, total BTEX (benzene, toluene, ethylbenzene, xylenes) and formaldehyde to indicators of local sources, adjusting for temporal variation. RESULTS: Total BTEX levels exhibited the most spatial variability, followed by benzene and formaldehyde (coefficient of variation of temporally adjusted measurements of 0.57, 0.35, 0.22, respectively). Total roadway length within 100 m, traffic signal density within 400 m of monitoring sites, and an indicator of temporal variation explained 65% of the total variability in benzene while 70% of the total variability in BTEX was accounted for by traffic signal density within 450 m, density of permitted solvent-use industries within 500 m, and an indicator of temporal variation. Measures of temporal variation, traffic signal density within 400 m, road length within 100 m, and interior building area within 100 m (indicator of heating fuel combustion) predicted 83% of the total variability of formaldehyde. The models built with the modeling subset were found to predict concentrations well, predicting 62% to 68% of monitored values at validation sites. CONCLUSIONS: Traffic and point source emissions cause substantial variation in street-level exposures to common toxic volatile organic compounds in New York City. Land-use regression models were successfully developed for benzene, formaldehyde, and total BTEX using spatial indicators of on-road vehicle emissions and emissions from stationary sources. These estimates will improve the understanding of health effects of individual pollutants in complex urban pollutant mixtures and inform local air quality improvement efforts that reduce disparities in exposure. Descriptors Links Book Title Database Publisher Data Source Authors Kheirbek,I., Johnson,S., Ross,Z., Pezeshki,G., Ito,K., Eisl,H., Matte,T. Original/Translated Title URL Date of Electronic 20120731 PMCID PMC3420325 Editors
Spatio-temporal dynamics of fishing effort in a multi-species artisanal diving fishery and its effects on catch variability: insights for sustainable management	2014		Read more...
Source Type Print(0) Ref Type Journal Article Periodical, Full Revista de biologia tropical Periodical, Abbrev. Rev.Biol.Trop. Pub Date Free Form Dec Volume 62 Issue 4 Start Page 1565 Other Pages 1586 Notes JID: 0404267; ppublish Place of Publication Costa Rica ISSN/ISBN 0034-7744; 0034-7744 Accession Number PMID: 25720188 Language spa SubFile English Abstract; Journal Article; Research Support, Non-U.S. Gov't; IM DOI Output Language Unknown(0) PMID 25720188 Abstract Artisanal diving fisheries are a source of income, employment and food security of coastal areas in many countries. Understanding the dynamics of these fisheries, including the spatial and temporal dynamics of fishing effort, gears and species can help to address the challenges involved in fisheries management. We aimed to analyze the differences in fishing strategies undertaken by fishers that use two different diving methods (hookah and free diving), the conditions and their potential impacts on catches when adjustments to those strategies are applied over time. For this, detailed information of fishing operations from artisanal boats in the North Pacific coast of Costa Rica was analyzed in two fishing seasons (2007-2008 and 2011-2012). Data were collected by onboard observers (fishing site, fishing time, species composition, depth and visibility). Additionally, interviews with divers were applied to obtain information of price per species, species volume and fishing operations. From the total number of trips during both seasons, hookah diving was represented by a sample size of 69.3%, while free diving, with a sample of 41.9%. More than 15 species were identified in each fishing season. Nevertheless, three categories had substantial contributions in both seasons with differences in the proportions for each case: green lobster (Panulirus gracilis), octopus (Octopus sp.) and parrotfish (Scarus perrico and S. ghobban). It is worth noting that an important proportion of catch was retained by fishers for personal consumption purposes, including species of high commercial value. Additional night diving activity, increased the number of dives from one season to another. Besides, cooperation processes in free diving fishing operations, and changes in fishing effort between seasons, defined important changes in fishing strategies. Potential causes of changes in fishing strategies and the implications for management to ensure the sustainability of these fisheries in the long term are discussed. Descriptors Links Book Title Database Publisher Data Source Authors Naranjo Madrigall,H., Salas Marquez,S. Original/Translated Title Dinamica espacio-temporal del esfuerzo en una pesqueria de buceo artesanal multiespecifica y sus efectos en la variabilidad de las capturas: Implicaciones para el manejo sostenible URL Date of Electronic PMCID Editors
Spearfishing as a potential threat to fishery sustainability in Jamaica: a survey of 23 fishing beaches	2014		Read more...
Source Type Print(0) Ref Type Journal Article Periodical, Full Rev Biol Trop Periodical, Abbrev. Rev.Biol.Trop. Pub Date Free Form Volume 62 Issue Start Page 392 Other Pages 400 Notes ID: 757344 Place of Publication ISSN/ISBN Accession Number Language en SubFile DOI Output Language Unknown(0) PMID Abstract Un estudio de la pesca submarina en Jamaica durante el 2011 revelÃ³ una pesquerÃa mayor que la esperada, que produce aproximadamente 4 000 toneladas por aÃ±o de todos los tipos de recursos pesqueros. Este nivel de producciÃ³n esta por encima de lo que se pensaba era una actividad pesquera de pequeÃ±a escala. Esta pesquerÃa especializada se ha ampliado aproximadamente en 1% de pescadores a al menos el 10%, en un periodo de 20 aÃ±os (1991 a 2011). Aunque los peces de coral se dominaran como otros recursos tales como langostas, concha y pulpo. Aunque no era un objetivo del censo se observaron muchos peces juveniles en las capturas con tamaÃ±os muy por debajo de su tamaÃ±o adulto u Ã³ptimo. Un total de 58% pescadores informaron que tendrÃan dificultad para encontrar otra opciÃ³n de empleo si la pesca submarina se prohibe. Los pescadores explotan recursos en la plataforma de la isla y tambiÃ©n en casi todos los bancos de la costa sobre todo en el Banco de Pedro. Este estudio tambiÃ©n muestra que comunmente se prÃ¡ctica la pesca submarina durante la noche con el fin de capturar peces de coral durmiendo. A pesar de que esta actividad es prohibida. Se recomienda que los pescadores se registren y que se regule la actividad. Posibles acciones incluyen considerar la prohibiciÃ³n parcial durante el aÃ±o o prohibir el uso de equipo de buceo y narguile.(AU) Descriptors Links http://www.scielo.sa.cr/scielo.php?script=sci_arttext&pid=S0034-77442014000700024 Book Title Database LILACS; http://www.globalhealthlibrary.net/ Publisher Data Source Authors Ennis,Zahra, Aiken,Karl Original/Translated Title URL Date of Electronic PMCID Editors
Spearfishing to depletion: evidence from temperate reef fishes in Chile	2010		Read more...
Source Type Print(0) Ref Type Journal Article Periodical, Full Ecol Appl Periodical, Abbrev. Ecol.Appl. Pub Date Free Form Volume 20 Issue 6 Start Page 1504 Other Pages 11 Notes ID: 20945755 Place of Publication ISSN/ISBN Accession Number Language en SubFile DOI Output Language Unknown(0) PMID Abstract Unreliable and data-poor marine fishery landings can lead to a lack of regulatory action in fisheries management. Here we use official Chilean landing reports and non-conventional indicators, such as fishers' perceptions and spearfishing competition results, to provide evidence of reef fishes depletions caused by unregulated spearfishing. Results show that the three largest and most emblematic reef fishes targeted mainly by spearfishers (> 98% of landings) Graus nigra (vieja negra), Semicossyphus darwini (sheephead or pejeperro), and Medialuna ancietae (acha)] show signs of depletion in terms of abundance and size and that overall the catches of reef fishes have shifted from large carnivore species toward smaller-sized omnivore and herbivore species. Information from two snorkeling speargun world championships (1971 and 2004, Iquique, Chile) and from fishers' perceptions shows the mean size of reef fish to be declining. Although the ecological consequences of reef fish depletion are not fully understood in Chile, evidence of spearfishing depleting temperate reef fishes must be explicitly included in policy debates. This would involve bans or strong restrictions on the use of SCUBA and hookah diving gear for spearfishing, and minimum size limits. It may also involve academic and policy discussions regarding conservation and fisheries management synergies within networks of no-take and territorial user-rights fisheries areas, as a strategy for the sustainable management of temperate and tropical reef fisheries. Descriptors Ecosystem, Fisheries, Fishes/physiology, Animals, Anthozoa, Chile, Conservation of Natural Resources, Oceans and Seas Links http://pesquisa.bvsalud.org/ghl/resource/en/mdl-20945755 Book Title Database MEDLINE; http://www.globalhealthlibrary.net/ Publisher Data Source Authors Godoy,Natalio, Gelcich,L. S., VÃ¡squez,Julio,A., Castilla,Juan Carlos Original/Translated Title URL Date of Electronic PMCID Editors
Specialized intestinal metaplasia of the distal esophagus in gastroesophageal reflux disease: prevalence and clinico-demographic features	2003	Hospital de Clinicas, Universidade Federal do Parana. lrcaum7@bol.com.br	Read more...
Source Type Print(0) Ref Type Journal Article Periodical, Full Arquivos de Gastroenterologia Periodical, Abbrev. Arq.Gastroenterol. Pub Date Free Form Oct-Dec Volume 40 Issue 4 Start Page 220 Other Pages 226 Notes LR: 20061115; JID: 15310600R; 2004/05/31 [aheadofprint]; ppublish Place of Publication Brazil ISSN/ISBN 0004-2803; 0004-2803 Accession Number PMID: 15264043 Language por SubFile English Abstract; Journal Article; IM DOI /S0004-28032003000400005 [doi] Output Language Unknown(0) PMID 15264043 Abstract BACKGROUND: Specialized intestinal metaplasia can be categorized according endoscopic and histological findings in long segment Barrett, short segment Barrett and specialized intestinal metaplasia of cardia. Barrett's esophagus is an acquired disease that is found in about 10%-13% of patients undergoing endoscopy for symptoms of gastroesophageal reflux disease and it is well established as predisposing to esophageal adenocarcinoma. The columnar epithelium with goblet cells replaces the normal squamous epithelium. OBJECTIVE: To determine the prevalence and clinical-demographic characteristics of specialized intestinal metaplasia of distal esophagus in the gastroesophageal reflux disease. METHODS: From April to October 2002, 402 patients referred to upper endoscopy due gastroesophageal reflux disease were evaluated through of a symptom questionnaire about clinical and demographic features and submitted to upper endoscopy with four-quadrant biopsies 1 cm below escamocolumnar junction. RESULTS: Eighteen point four percent of patients had specialized intestinal metaplasia, 0.5% long segment Barrett esophagus, 3.2% short segment Barrett's esophagus and 14.7% specialized intestinal metaplasia of cardia. Patients with Barrett's esophagus showed a tendency to be male and specialized metaplasia of cardia to be female. All patients with Barrett's esophagus were white. There was not association between symptoms of gastroesophageal reflux disease and specialized intestinal metaplasia, but patients with Barrett's esophagus showed a tendency to have symptoms over 5 years and had more hiatal hernia and esophagitis. The use of alcohol and tobacco was not related to the presence of specialized intestinal metaplasia. CONCLUSIONS: Barrett's esophagus was more related to the male gender, gastroesophageal reflux disease symptoms for 5 years or longer, more intense esophagitis and hiatal hernia, but was not related to the use of tobacco and alcohol. Descriptors Adolescent, Aged, Aged, 80 and over, Barrett Esophagus/epidemiology/pathology, Brazil/epidemiology, Cardia/pathology, Female, Gastroesophageal Reflux/physiopathology, Humans, Intestinal Diseases/epidemiology/pathology, Male, Metaplasia/epidemiology, Middle Aged, Prevalence, Prospective Studies, Stomach Diseases/epidemiology/pathology Links Book Title Database Publisher Data Source Authors Caum,L. C., Bizinelli,S. L., Pisani,J. C., Amarantes,H. M., Ioshii,S. O., Carmes,E. R. Original/Translated Title Metaplasia intestinal especializada de esofago distal na doenca do refluxo gastroesofagico: prevalencia e aspectos clinico-epidemiologicos URL Date of Electronic 20040531 PMCID Editors
Speciation of organotins in poly(vinyl chloride) products	1993	Forsyth, D.S., Food Research Division, Bureau of Chemical Safety, Health Protection Branch, Ottawa, Ont. K1A 0L2, Canada	Read more...
Source Type Print(0) Ref Type Journal Article Periodical, Full Food additives and contaminants Periodical, Abbrev. Food Addit.Contam. Pub Date Free Form 1993/ Volume 10 Issue 5 Start Page 531 Other Pages 540 Notes Place of Publication ISSN/ISBN 0265-203X Accession Number Language SubFile DOI Output Language Unknown(0) PMID Abstract Extraction studies on butyl- and octyltins were conducted with three poly(vinyl chloride) (PVC) product types: clear food container, rigid pipe and flexible membrane. Three solvents, tetrahydrofuran, xylene and methylene chloride were evaluated for extraction efficiency. Methylene chloride extracted more than 97% of the total extractable organotin in two extractions and resulted in the highest recoveries of analytes from all three PVC products. Method detection limits ranged from 0.3 to 0.9 Î¼g alkyltin/g PVC. The mean precision of the method is 6.8% relative standard deviation. Food industry PVC product samples contained between <0.8 and 8751 Î¼g/g octyltins and <0.3 and 4.7Î¼g/g butyltins. Butyltins (<0.9-5985 Î¼g/g) were detected in potable water pipe samples. Pipe used in industrial applications contained both butyl- (13-1501 Î¼g/g) and octyltins (701-3033 Î¼g/g). Descriptors butyltin, dichloromethane, drinking water, organotin compound, polyvinylchloride, solvent, tetrahydrofuran, xylene, article, container, extraction, food packaging, food safety, water supply Links Book Title Database Embase; MEDLINE Publisher Data Source Embase Authors Forsyth,D. S., Dabeka,R., Sun,W. F., Dalglish,K. Original/Translated Title URL Date of Electronic PMCID Editors
Species and susceptibility distribution of 1062 clinical yeast isolates to azoles, echinocandins, flucytosine and amphotericin B from a multi-centre study	2012	Mikrobiologische Beratung and Service, Munchen, Germany Division of Clinical Microbiology, Department of Laboratory Medicine, University Vienna, Austria.	Read more...
Source Type Print(0) Ref Type Journal Article Periodical, Full Mycoses Periodical, Abbrev. Mycoses Pub Date Free Form May Volume 55 Issue 3 Start Page e124 Other Pages 37 Notes LR: 20131121; CI: (c) 2012; JID: 8805008; 0 (Antifungal Agents); 0 (Azoles); 0 (Echinocandins); 7XU7A7DROE (Amphotericin B); D83282DT06 (Flucytosine); 2012/01/11 [aheadofprint]; ppublish Place of Publication Germany ISSN/ISBN 1439-0507; 0933-7407 Accession Number PMID: 22233267 Language eng SubFile Journal Article; Multicenter Study; Research Support, Non-U.S. Gov't; IM DOI 10.1111/j.1439-0507.2011.02165.x [doi] Output Language Unknown(0) PMID 22233267 Abstract Descriptive values were determined for eight antifungal agents within the course of a multi-centre study encompassing 1062 German and Austrian clinical yeast isolates. Candida albicans (54%) was the predominant species isolated followed by Candida glabrata (22%), Candida parapsilosis (6%), Candida tropicalis (5.7%), Candida krusei (4.3%), as well as eleven further candidal and four non-Candida yeast species. While 519 (48.9%) isolates were tested susceptible to all antifungals tested, no isolate was found to exhibit complete cross resistance. For C. albicans, the proportions of susceptible isolates were 93.2% (amphotericin B), 95.6% (flucytosine), 84.3% (fluconazole), 83.8% (posaconazole), 91.8% (voriconazole), 96.5% (anidulafungin), 96.2% (caspofungin) and 97.6% (micafungin). Patterns of complete parallel resistances were observed within azoles (8.8%) and echinocandins (1.7%). While a decreased susceptibility was found infrequently for echinocandins and flucytosine, it was more common for azoles with highest proportions for isolates of C. glabrata (fluconazole, 40.6%; posaconazole, 37.2%), Candida guilliermondii (fluconazole and posaconazole, each 25.0%), C. krusei (posaconazole, 28.3%; voriconazole, 60%), C. parapsilosis (fluconazole, 70.3%) and C. tropicalis (fluconazole, 62.3%). The descriptive values obtained in this study represent a valid basis for the comparison of recent and future epidemiological surveys to analyse the susceptibility of yeast isolates towards major antifungal substances. Descriptors Links Book Title Database Publisher Blackwell Verlag GmbH Data Source Authors Schmalreck,A.F., Willinger,B., Haase,G., Blum,G., Lass-Florl,C., Fegeler,W., Becker,K., Antifungal Susceptibility Testing-AFST Study Group Original/Translated Title URL Date of Electronic 20120111 PMCID Editors
Species-specific and drug-specific differences in susceptibility of Candida biofilms to echinocandins: characterization of less common bloodstream isolates	2013	Laboratory of Infectious Diseases, 3rd Department of Pediatrics, Aristotle University School of Medicine, Hippokration Hospital, Thessaloniki, Greece.	Read more...
Source Type Print(0) Ref Type Journal Article Periodical, Full Antimicrobial Agents and Chemotherapy Periodical, Abbrev. Antimicrob.Agents Chemother. Pub Date Free Form Jun Volume 57 Issue 6 Start Page 2562 Other Pages 2570 Notes LR: 20150427; JID: 0315061; 0 (Antifungal Agents); 0 (Echinocandins); 0 (Lipopeptides); 9HLM53094I (anidulafungin); F0XDI6ZL63 (caspofungin); R10H71BSWG (micafungin); OID: NLM: PMC3716187; 2013/03/25 [aheadofprint]; ppublish Place of Publication United States ISSN/ISBN 1098-6596; 0066-4804 Accession Number PMID: 23529739 Language eng SubFile Journal Article; Research Support, Non-U.S. Gov't; IM DOI 10.1128/AAC.02541-12 [doi] Output Language Unknown(0) PMID 23529739 Abstract Candida species other than Candida albicans are increasingly recognized as causes of biofilm-associated infections. This is a comprehensive study that compared the in vitro activities of all three echinocandins against biofilms formed by different common and infrequently identified Candida isolates. We determined the activities of anidulafungin (ANID), caspofungin (CAS), and micafungin (MFG) against planktonic cells and biofilms of bloodstream isolates of C. albicans (15 strains), Candida parapsilosis (6 strains), Candida lusitaniae (16 strains), Candida guilliermondii (5 strains), and Candida krusei (12 strains) by XTT [2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] assay. Planktonic and biofilm MICs were defined as >/= 50% fungal damage. Planktonic cells of all Candida species were susceptible to the three echinocandins, with MICs of /= 32 mg/liter. In contrast, the MICs of all three echinocandins for C. albicans and C. krusei biofilms were relatively low (MICs = 1 mg/liter). While echinocandins exhibited generally high MICs against C. parapsilosis biofilms, MFG exhibited the lowest MICs against these isolates (4 mg/liter). A paradoxical growth effect was observed with CAS concentrations ranging from 8 to 64 mg/liter against C. albicans and C. parapsilosis biofilms but not against C. krusei, C. lusitaniae, or C. guilliermondii. While non-albicans Candida planktonic cells were susceptible to all echinocandins, there were drug- and species-specific differences in susceptibility among biofilms of the various Candida species, with C. lusitaniae and C. guilliermondii exhibiting profiles of high MICs of the three echinocandins. Descriptors Links Book Title Database Publisher Data Source Authors Simitsopoulou,M., Peshkova,P., Tasina,E., Katragkou,A., Kyrpitzi,D., Velegraki,A., Walsh,T.J., Roilides,E. Original/Translated Title URL Date of Electronic 20130325 PMCID PMC3716187 Editors
Species-specific partitioning of soil water resources in an old-growth Douglas-fir-western hemlock forest	2007	USDA Forest Service, Forestry Sciences Laboratory, 3200 SW Jefferson Way, Corvallis, OR 97331, USA. fmeinzer@fs.fed.us	Read more...
Source Type Print(0) Ref Type Journal Article Periodical, Full Tree physiology Periodical, Abbrev. Tree Physiol. Pub Date Free Form Jun Volume 27 Issue 6 Start Page 871 Other Pages 880 Notes LR: 20131121; JID: 100955338; 0 (Soil); 059QF0KO0R (Water); ppublish Place of Publication Canada ISSN/ISBN 0829-318X; 0829-318X Accession Number PMID: 17331905 Language eng SubFile Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.; IM DOI Output Language Unknown(0) PMID 17331905 Abstract Although tree- and stand-level estimates of forest water use are increasingly common, relatively little is known about partitioning of soil water resources among co-occurring tree species. We studied seasonal courses of soil water utilization in a 450-year-old Pseudotsuga menziesii (Mirb.) Franco-Tsuga heterophylla (Raf.) Sarg. forest in southwestern Washington State. Soil volumetric water content (theta) was continuously monitored with frequency domain capacitance sensors installed at eight depths from 0.2 to 2 m at four locations in the vicinity of each species. Vertical profiles of root distribution and seasonal and daily courses of hydraulic redistribution (HR), sap flow and tree water status were also measured. Mean root area in the upper 60 cm of soil was significantly greater in the vicinity of T. heterophylla trees. However, seasonal water extraction on a root area basis was significantly greater near P. menziesii trees at all depths between 15 and 65 cm, leading to significantly lower water storage in the upper 65 cm of soil near P. menziesii trees at the end of the summer dry season. Greater apparent efficiency of P. menziesii roots at extracting soil water was attributable to a greater driving force for water uptake rather than to differences in root hydraulic properties between the species. The dependence of HR on theta was similar in soil near individuals of both species, but seasonal maximum rates of HR were greater in soil near P. menziesii because minimum values of theta were lower, implying a steeper water potential gradient between the upper and lower soil that acted as a driving force for water efflux from shallow roots. The results provide information on functional traits relevant for understanding the ecological distributions of these species and have implications for spatial variability of processes such as soil respiration and nutrient cycling. Descriptors Plant Roots/metabolism/physiology, Plant Transpiration/physiology, Pseudotsuga/metabolism/physiology, Soil, Species Specificity, Tsuga/metabolism/physiology, Water/metabolism Links Book Title Database Publisher Data Source Authors Meinzer,F. C., Warren,J. M., Brooks,J. R. Original/Translated Title URL Date of Electronic PMCID Editors

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