Open AccessSeasonal patterns of gross primary production and ecosystem respiration in an alpine meadow ecosystem on the Qinghai‐Tibetan Plateau
Author(s) -
Kato Tomomichi,
Tang Yanhong,
Gu Song,
Hirota Mitsuru,
Cui Xiaoyong,
Du Mingyuan,
Li Yingnian,
Zhao Xinquan,
Oikawa Takehisa
Publication year - 2004
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2003jd003951
Subject(s) - ecosystem respiration , primary production , eddy covariance , ecosystem , environmental science , atmospheric sciences , terrestrial ecosystem , plateau (mathematics) , carbon sink , growing season , ecology , biology , geology , mathematical analysis , mathematics
We measured the net ecosystem CO 2 exchange (NEE) in an alpine meadow ecosystem (latitude 37°29′–45′N, longitude 101°12′–23′E, 3250 m above sea level) on the Qinghai‐Tibetan Plateau throughout 2002 by the eddy covariance method to examine the carbon dynamics and budget on this unique plateau. Diurnal changes in gross primary production (GPP) and ecosystem respiration (R e ) showed that an afternoon increase of NEE was highly associated with an increase of R e . Seasonal changes in GPP corresponded well to changes in the leaf area index and daily photosynthetic photon flux density. The ratio of GPP/R e was high and reached about 2.0 during the peak growing season, which indicates that mainly autotrophic respiration controlled the carbon dynamics of the ecosystem. Seasonal changes in mean GPP and R e showed compensatory behavior as reported for temperate and Mediterranean ecosystems, but those of GPP max and R emax were poorly synchronized. The alpine ecosystem exhibited lower GPP (575 g C m −2 y −1 ) than, but net ecosystem production (78.5 g C m −2 y −1 ) similar to, that of subalpine forest ecosystems. The results suggest that the alpine meadow behaved as a CO 2 sink during the 1‐year measurement period but apparently sequestered a rather small amount of C in comparison with similar alpine ecosystems.