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Carbon sequestration and ecosystem respiration for 4 years in a Scots pine forest
Author(s) -
Zha Tianshan,
Kellomäki Seppo,
Wang KaiYun,
Rouvinen Ismo
Publication year - 2004
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1111/j.1365-2486.2004.00835.x
Subject(s) - scots pine , photosynthetically active radiation , eddy covariance , ecosystem respiration , primary production , ecosystem , environmental science , growing season , respiration , soil respiration , seasonality , zoology , biometeorology , photosynthesis , carbon sequestration , carbon dioxide , atmospheric sciences , botany , pinus <genus> , ecology , canopy , biology , geology
The net exchange of CO 2 (NEE) between a Scots pine ( Pinus sylvestris L.) forest ecosystem in eastern Finland and the atmosphere was measured continuously by the eddy covariance (EC) technique over 4 years (1999–2002). The annual temperature coefficient ( Q 10 ) of ecosystem respiration ( R ) for these years, respectively, was 2.32, 2.66, 2.73 and 2.69. The light‐saturated rate of photosynthesis ( A max ) was highest in July or August, with an annual average A max of 10.9, 14.6, 15.3 and 17.1 μmol m −2 s −1 in the 4 years, respectively. There was obvious seasonality in NEE, R and gross primary production (GPP), exhibiting a similar pattern to photosynthetically active radiation (PAR) and air temperature. The integrated daily NEE ranged from 2.59 to −4.97 g C m −2 day −1 in 1999, from 2.70 to −4.72 in 2000, from 2.61 to −4.71 in 2001 and from 5.27 to −4.88 in 2002. The maximum net C uptake occurred in July, with the exception of 2000, when it was in June. The interannual variation in ecosystem C flux was pronounced. The length of the growing season, based on net C uptake, was 179, 170, 175 and 176 days in 1999–2002, respectively, and annual net C sequestration was 152, 101, 172 and 205 g C m −2 yr −1 . It is estimated that ecosystem respiration contributed 615, 591, 752 and 879 g C m −2 yr −1 to the NEE in these years, leading to an annual GPP of −768, −692, −924 and −1084 g C m −2 yr −1 . It is concluded that temperature and PAR were the main determinants of the ecosystem CO 2 flux. Interannual variations in net C sequestration are predominantly controlled by average air temperature and integrated radiation in spring and summer. Four years of EC data indicate that boreal Scots pine forest ecosystem in eastern Finland acts as a relatively powerful carbon sink. Carbon sequestration may benefit from warmer climatic conditions.