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Titolo:
LEAF, BRANCH, STAND AND LANDSCAPE SCALE MEASUREMENTS OF VOLATILE ORGANIC-COMPOUND FLUXES FROM US WOODLANDS
Autore:
GUENTHER A; GREENBERG J; HARLEY P; HELMIG D; KLINGER L; VIERLING L; ZIMMERMAN P; GERON C;
Indirizzi:
NATL CTR ATMOSPHER RES,DIV ATMOSPHER CHEM,POB 3000 BOULDER CO 80307 US EPA RES TRIANGLE PK NC 27711
Titolo Testata:
Tree physiology
fascicolo: 1-2, volume: 16, anno: 1996,
pagine: 17 - 24
SICI:
0829-318X(1996)16:1-2<17:LBSALS>2.0.ZU;2-Z
Fonte:
ISI
Lingua:
ENG
Soggetto:
HYDROCARBONS; ISOPRENE;
Keywords:
BIOGENIC EMISSION MODEL; DIURNAL VARIATION; HEXENOL DERIVATIVES; ISOPRENE; MONOTERPENES; SESQUITERPENES; SPATIAL VARIATION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
21
Recensione:
Indirizzi per estratti:
Citazione:
A. Guenther et al., "LEAF, BRANCH, STAND AND LANDSCAPE SCALE MEASUREMENTS OF VOLATILE ORGANIC-COMPOUND FLUXES FROM US WOODLANDS", Tree physiology, 16(1-2), 1996, pp. 17-24

Abstract

Natural volatile organic compound (VOC) fluxes were measured in threeU.S. woodlands in summer 1993. Fluxes from individual leaves and branches were estimated with enclosure techniques and used to initialize and evaluate VOC emission model estimates. Ambient measurements were used to estimate above canopy fluxes for entire stands and landscapes. The branch enclosure experiments revealed 78 VOCs. Hexenol derivatives were the most commonly observed oxygenated compounds. The branch measurements also revealed high rates of isoprene emission from three genera of plants (Albizia, Chusqua and Mahonia) and high rates of moneterpene emission from three genera (Atriplex Chrysthamnus and Sorbus) for which VOC emission rates have not been reported. Measurements on an additional 34 species confirmed previous results. Leaf enclosure measurements of isoprene emission rates from Quercus were substantially higherthan the rates used in existing emission models. Model predictions ofdiurnal variations in isoprene fluxes were generally within +/- 35% of observed flux variations. Measurements with a fast response analyzerdemonstrated that 60 min is a reasonable time resolution for biogenicemission models. Average daytime stand scale (hundreds of m) flux measurements ranged from about 1.3 mg C m(-2) h(-1) for a shrub oak standto 1.5-2.5 mg C m(-2) h(-1) for a mixed forest stand. Morning, evening and nighttime fluxes were less than 0.1 mg C m(-2) h(-1). Average daytime landscape scale (tens of km) flux measurements ranged from about3 mg C m(-2) h(-1) for a shrub oak-aspen and rangeland landscape to about 7 mg C m(-2) h(-1) for a deciduous forest landscape. Fluxes predicted by recent versions (BEIS2, BEIS2.1) of a biogenic emission model were within 10 to 50% of observed fluxes and about 300% higher than those predicted by a previous version of the model (BEIS).

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 05/07/20 alle ore 13:34:56