TY - JOUR
T1 - Seasonal shift in factors controlling net ecosystem production in a high Arctic terrestrial ecosystem
AU - Uchida, Masaki
AU - Kishimoto, Ayaka
AU - Muraoka, Hiroyuki
AU - Nakatsubo, Takayuki
AU - Kanda, Hiroshi
AU - Koizumi, Hiroshi
PY - 2010/1
Y1 - 2010/1
N2 - We examined factors controlling temporal changes in net ecosystem production (NEP) in a high Arctic polar semi-desert ecosystem in the snow-free season. We examined the relationships between NEP and biotic and abiotic factors in a dominant plant community (Salix polaris-moss) in the Norwegian high Arctic. Just after snowmelt in early July, the ecosystem released CO2 into the atmosphere. A few days after snowmelt, however, the ecosystem became a CO2 sink as the leaves of S. polaris developed. Diurnal changes in NEP mirrored changes in light incidence (photosynthetic photon flux density, PPFD) in summer. NEP was significantly correlated with PPFD when S. polaris had fully developed leaves, i. e., high photosynthetic activity. In autumn, NEP values decreased as S. polaris underwent senescence. During this time, CO2 was sometimes released into the atmosphere. In wet conditions, moss made a larger contribution to NEP. In fact, the water content of the moss regulated NEP during autumn. Our results indicate that the main factors controlling NEP in summer are coverage and growth of S. polaris, PPFD, and precipitation. In autumn, the main factor controlling NEP is moss water content.
AB - We examined factors controlling temporal changes in net ecosystem production (NEP) in a high Arctic polar semi-desert ecosystem in the snow-free season. We examined the relationships between NEP and biotic and abiotic factors in a dominant plant community (Salix polaris-moss) in the Norwegian high Arctic. Just after snowmelt in early July, the ecosystem released CO2 into the atmosphere. A few days after snowmelt, however, the ecosystem became a CO2 sink as the leaves of S. polaris developed. Diurnal changes in NEP mirrored changes in light incidence (photosynthetic photon flux density, PPFD) in summer. NEP was significantly correlated with PPFD when S. polaris had fully developed leaves, i. e., high photosynthetic activity. In autumn, NEP values decreased as S. polaris underwent senescence. During this time, CO2 was sometimes released into the atmosphere. In wet conditions, moss made a larger contribution to NEP. In fact, the water content of the moss regulated NEP during autumn. Our results indicate that the main factors controlling NEP in summer are coverage and growth of S. polaris, PPFD, and precipitation. In autumn, the main factor controlling NEP is moss water content.
KW - Carbon dioxide
KW - Climate change
KW - High Arctic
KW - Moss
KW - Net ecosystem production
KW - Salix polaris
UR - http://www.scopus.com/inward/record.url?scp=72249101522&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=72249101522&partnerID=8YFLogxK
U2 - 10.1007/s10265-009-0260-6
DO - 10.1007/s10265-009-0260-6
M3 - Article
C2 - 19760136
AN - SCOPUS:72249101522
SN - 0918-9440
VL - 123
SP - 79
EP - 85
JO - Journal of Plant Research
JF - Journal of Plant Research
IS - 1
ER -