Prediction of photosynthesis in Scots pine ecosystems across Europe by a needle-level theory

• Published in: Atmospheric chemistry and physics 2018-09, Vol.18 (18), p.13321-13328
• Main Authors: Hari, Pertti, Noe, Steffen, Dengel, Sigrid, Elbers, Jan, Gielen, Bert, Kerminen, Veli-Matti, Kruijt, Bart, Kulmala, Liisa, Lindroth, Anders, Mammarella, Ivan, Petäjä, Tuukka, Schurgers, Guy, Vanhatalo, Anni, Kulmala, Markku, Bäck, Jaana
• Format: Article
• Language: English
• Subjects: Alterra - Climate change and adaptive land and water management; Alterra - Klimaatverandering en adaptief land- en watermanagement; Analysis; Annual variations; Boreal forests; Carbon dioxide; Carbon dioxide flux; Climate Change; Climate Change and Adaptive Land and Water Management; Covariance; Dynamics; Earth and Related Environmental Sciences; Ecosystems; Eddy covariance; Environmental aspects; Fluxes; Forest dynamics; Forests; Geovetenskap och miljövetenskap; Klimaatverandering; Klimaatverandering en adaptief land- en watermanagement; Light intensity; Luminous intensity; Macromolecules; Mathematical analysis; Metabolism; Meteorologi och atmosfärforskning; Meteorology and Atmospheric Sciences; Natural Sciences; Naturvetenskap; Photosynthesis; Physiological aspects; Phytochemistry; Pine; Pine trees; Pinus sylvestris; Stomata; Timberline; Water Systems and Global Change; WIMEK
• ISSN: 1680-7324; 1680-7316; 1680-7324
• DOI: 10.5194/acp-18-13321-2018

Photosynthesis provides carbon for the synthesis of macromolecules to construct cells during growth. This is the basis for the key role of photosynthesis in the carbon dynamics of ecosystems and in the biogenic CO2 assimilation. The development of eddy-covariance (EC) measurements for ecosystem CO2 fluxes started a new era in the field studies of photosynthesis. However, the interpretation of the very variable CO2 fluxes in evergreen forests has been problematic especially in transition times such as the spring and autumn. We apply two theoretical needle-level equations that connect the variation in the light intensity, stomatal action and the annual metabolic cycle of photosynthesis. We then use these equations to predict the photosynthetic CO2 flux in five Scots pine stands located from the northern timberline to Central Europe. Our result has strong implications for our conceptual understanding of the effects of the global change on the processes in boreal forests, especially of the changes in the metabolic annual cycle of photosynthesis.