Characterizing nitric oxide emissions from two typical alpine ecosystems.
J Environ Sci (China)
; 77: 312-322, 2019 Mar.
Article
en En
| MEDLINE
| ID: mdl-30573095
ABSTRACT
A portion of alpine meadows has been and will continue to be cultivated due to the concurrent increasing demands for animal- and crop-oriented foods and global warming. However, it remains unclear how these long-term changes in land use will affect nitric oxide (NO) emission. At a field site with a calcareous soil on the Qinghai-Tibetan Plateau, the authors measured the year-round NO fluxes and related variables in a typically winter-grazed natural alpine meadow (NAM) and its adjacent forage oat field (FOF). The results showed that long-term plow tillage, fertilization and growing forage oats significantly yielded ca. 2.7 times more (pâ¯<â¯0.01) NO emissions from the FOF than the NAM (conservatively 208 vs. 56â¯gâ¯N/(ha·year) on average). The spring freeze-thaw period and non-growing season accounted for 17%-35% of the annual emissions, respectively. The Q10 of surface soil temperature (Ts) was 8.9 in the NAM (vs. 3.8 in the FOF), indicating increases of 24%-93% in NO emissions per 1-3⯰C increase. However, the warming-induced increases could be smaller than those due to land use change and management practices. The Ts and concentrations of ammonium, nitrate and water-extractable organic carbon jointly explained 69% of the variance in daily NO fluxes from both fields during the annual period (pâ¯<â¯0.001). This result indicates that temporally and/or spatially distributed NO fluxes from landscapes with calcareous soils across native alpine meadows and/or fields cultivated with forage oats can be predicted by simultaneous observations of these four soil variables.
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Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Ecosistema
/
Óxido Nítrico
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
J Environ Sci (China)
Asunto de la revista:
SAUDE AMBIENTAL
Año:
2019
Tipo del documento:
Article
País de afiliación:
China