Interpreting canopy development and physiology using a European phenology camera network at flux sites

Show simple item record Wingate, L. Ogee, J. Cremonese, E. Filippa, G. Mizunuma, T. Migliavacca, M. Moisy, C. Wilkinson, M. Moureaux, C. Wohlfahrt, G. Hammerle, A. Hoertnagl, L. Gimeno, C. Porcar-Castell, A. Galvagno, M. Nakaji, T. Morison, J. Kolle, O. Knohl, A. Kutsch, W. Kolari, P. Nikinmaa, E. Ibrom, A. Gielen, B. Eugster, W. Balzarolo, M. Papale, D. Klumpp, K. Koestner, B. Gruenwald, T. Joffre, R. Ourcival, J. -M. Hellstrom, M. Lindroth, A. George, C. Longdoz, B. Genty, B. Levula, J. Heinesch, B. Sprintsin, M. Yakir, D. Manise, T. Guyon, D. Ahrends, H. Plaza-Aguilar, A. Guan, J. H. Grace, J. 2016-05-11T12:15:02Z 2016-05-11T12:15:02Z 2015
dc.identifier.citation Wingate , L , Ogee , J , Cremonese , E , Filippa , G , Mizunuma , T , Migliavacca , M , Moisy , C , Wilkinson , M , Moureaux , C , Wohlfahrt , G , Hammerle , A , Hoertnagl , L , Gimeno , C , Porcar-Castell , A , Galvagno , M , Nakaji , T , Morison , J , Kolle , O , Knohl , A , Kutsch , W , Kolari , P , Nikinmaa , E , Ibrom , A , Gielen , B , Eugster , W , Balzarolo , M , Papale , D , Klumpp , K , Koestner , B , Gruenwald , T , Joffre , R , Ourcival , J -M , Hellstrom , M , Lindroth , A , George , C , Longdoz , B , Genty , B , Levula , J , Heinesch , B , Sprintsin , M , Yakir , D , Manise , T , Guyon , D , Ahrends , H , Plaza-Aguilar , A , Guan , J H & Grace , J 2015 , ' Interpreting canopy development and physiology using a European phenology camera network at flux sites ' , Biogeosciences , vol. 12 , no. 20 , pp. 5995-6015 .
dc.identifier.other PURE: 56320575
dc.identifier.other PURE UUID: 97c6a29b-1a2a-4d54-a5ad-843303c8be06
dc.identifier.other WOS: 000363182200007
dc.identifier.other Scopus: 84945348954
dc.identifier.other ORCID: /0000-0001-7271-633X/work/29181743
dc.description.abstract Plant phenological development is orchestrated through subtle changes in photoperiod, temperature, soil moisture and nutrient availability. Presently, the exact timing of plant development stages and their response to climate and management practices are crudely represented in land surface models. As visual observations of phenology are laborious, there is a need to supplement long-term observations with automated techniques such as those provided by digital repeat photography at high temporal and spatial resolution. We present the first synthesis from a growing observational network of digital cameras installed on towers across Europe above deciduous and evergreen forests, grasslands and croplands, where vegetation and atmosphere CO2 fluxes are measured continuously. Using colour indices from digital images and using piecewise regression analysis of time series, we explored whether key changes in canopy phenology could be detected automatically across different land use types in the network. The piecewise regression approach could capture the start and end of the growing season, in addition to identifying striking changes in colour signals caused by flowering and management practices such as mowing. Exploring the dates of green-up and senescence of deciduous forests extracted by the piecewise regression approach against dates estimated from visual observations, we found that these phenological events could be detected adequately (RMSE <8 and 11 days for leaf out and leaf fall, respectively). We also investigated whether the seasonal patterns of red, green and blue colour fractions derived from digital images could be modelled mechanistically using the PROSAIL model parameterised with information of seasonal changes in canopy leaf area and leaf chlorophyll and carotenoid concentrations. From a model sensitivity analysis we found that variations in colour fractions, and in particular the late spring 'green hump' observed repeatedly in deciduous broadleaf canopies across the network, are essentially dominated by changes in the respective pigment concentrations. Using the model we were able to explain why this spring maximum in green signal is often observed out of phase with the maximum period of canopy photosynthesis in ecosystems across Europe. Coupling such quasi-continuous digital records of canopy colours with co-located CO2 flux measurements will improve our understanding of how changes in growing season length are likely to shape the capacity of European ecosystems to sequester CO2 in the future. en
dc.format.extent 21
dc.language.iso eng
dc.relation.ispartof Biogeosciences
dc.rights cc_by
dc.rights.uri info:eu-repo/semantics/openAccess
dc.subject SCOTS PINE
dc.subject 1181 Ecology, evolutionary biology
dc.subject 4112 Forestry
dc.subject 114 Physical sciences
dc.subject 1172 Environmental sciences
dc.title Interpreting canopy development and physiology using a European phenology camera network at flux sites en
dc.type Article
dc.contributor.organization Department of Forest Sciences
dc.contributor.organization Department of Physics
dc.contributor.organization Eero Nikinmaa / Principal Investigator
dc.contributor.organization Viikki Plant Science Centre (ViPS)
dc.contributor.organization Ecosystem processes (INAR Forest Sciences)
dc.contributor.organization Micrometeorology and biogeochemical cycles
dc.contributor.organization Forest Ecology and Management
dc.description.reviewstatus Peer reviewed
dc.relation.issn 1726-4170
dc.rights.accesslevel openAccess
dc.type.version publishedVersion
dc.relation.funder Unknown funder

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