Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Nitrogen oxide fluxes and nitrogen cycling during postagricultural succession and forest fertilization in the humid tropics
Autore:
Erickson, H; Keller, M; Davidson, EA;
Indirizzi:
USDA, Forest Serv, Int Inst Trop Forestry, Rio Piedras, PR 00928 USA USDARio Piedras PR USA 00928 st Trop Forestry, Rio Piedras, PR 00928 USA Woods Hole Res Ctr, Woods Hole, MA 02543 USA Woods Hole Res Ctr Woods Hole MA USA 02543 Ctr, Woods Hole, MA 02543 USA
Titolo Testata:
ECOSYSTEMS
fascicolo: 1, volume: 4, anno: 2001,
pagine: 67 - 84
SICI:
1432-9840(200101/02)4:1<67:NOFANC>2.0.ZU;2-F
Fonte:
ISI
Lingua:
ENG
Soggetto:
SOUTHWESTERN BRAZILIAN AMAZON; LUQUILLO-EXPERIMENTAL-FOREST; PUERTO-RICO; SOIL CARBON; RAIN-FOREST; COSTA-RICA; PASTURE CHRONOSEQUENCE; ECOSYSTEM DEVELOPMENT; SECONDARY SUCCESSION; PRIMARY PRODUCTIVITY;
Keywords:
nitrous oxide; nitric oxide; soil N availability; litterfall C : N ratio; tropical forests; net nitrogen mineralization; legumes; secondary succession; land-use change; forest fertilization;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
71
Recensione:
Indirizzi per estratti:
Indirizzo: Erickson, H Univ Metropolitana, Dept Sci & Technol, POB 21150, San Juan, PR 00928 USA Univ Metropolitana POB 21150 San Juan PR USA 00928 R 00928 USA
Citazione:
H. Erickson et al., "Nitrogen oxide fluxes and nitrogen cycling during postagricultural succession and forest fertilization in the humid tropics", ECOSYSTEMS, 4(1), 2001, pp. 67-84

Abstract

The effects of changes in tropical land use on soil emissions of nitrous oxide (N2O) and nitric oxide (NO) are not well understood. We examined emissions of N2O and NO and their relationships to land use and forest composition, litterfall, soil nitrogen (N) pools and turnover, soil moisture, and patterns of carbon (C) cycling in a lower montane, subtropical wet region of Puerto Rico. Fluxes of N2O and NO were measured monthly for over 1 year in old (more than 60 years old) pastures, early- and mid-successional forests previously in pasture, and late-successional forests not known to have beenin pasture within the tabonuco (Dacryodes excelsa) forest zone. Additional, though less frequent, measures were also made in an experimentally fertilized tabonuco forest. N2O fluxes exceeded NO fluxes at all sites, reflecting the consistently wet environment. The fertilized forest had the highest Noxide emissions (22.0 kg . N . ha(-1) . y(-1)). Among the unfertilized sites, the expected pattern of increasing emissions with stand age did not occur in all cases. The mid-successional forest most dominated by leguminous trees had the highest emissions (9.0 kg N . ha(-1) . y(-1)), whereas the mid-successional forest lacking legumes had the lowest emissions (0.09 kg N . ha(-1) . y(-1)). N oxide fluxes from late-successional forests were higher than fluxes from pastures. Annual N oxide fluxes correlated positively to leaf litter N, net nitrification potential nitrification, soil nitrate, and net N mineralization and negatively to leaf litter C:N ratio. Soil ammoniumwas not related to N oxide emissions. Forests with lower fluxes of N oxides had higher rates of C mineralization than sites with higher N oxide emissions. We conclude that (a) N oxide fluxes were substantial where the availability of inorganic N exceeded the requirements of competing biota; (b) species composition resulting from historical land use or varying successionaldynamics played an important role in determining N availability; and (c) the established ecosystem models that predict N oxide loss from positive relationships with soil ammonium may need to be modified.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 27/09/20 alle ore 19:21:12