Correction of PRI for carotenoid pigment pools improves photosynthesis estimation across different irradiance and temperature conditions
Kováč, Daniel (Global Change Research Institute CAS)
Veselá, Barbora (Czech Academy of Sciences. Global Change Research Institute)
Klem, Karel (Czech Academy of Sciences. Global Change Research Institute)
Večeřová, Kristýna (Global Change Research Institute CAS)
Materová Kmeco, Zuzana (Ostrava University)
Peñuelas, Josep (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Urban, Otmar (Global Change Research Institute CAS)

Date:	2020
Abstract:	We studied the influence of changing carotenoid pigments on the sensitivity of the photochemical reflectance index (PRI) to photosynthesis dynamics. The goal of the measurements was to examine how the introduction of ΔPRI into the working dataset can improve the estimation of photosynthesis. Spectral and photosynthetic characteristics of European beech and Norway spruce saplings were periodically measured in growth chambers with an adjustable irradiance and temperature. Patterns of environmental changes inside the growth chambers were created by periodic changes in irradiance and temperature. Four general irradiance periods lasting 10-12 days each were established. Introduced irradiance regimes varied in the sum of daily irradiance and amplitude of irradiance changes. Temperature was changed with more complex patterns to induce changes in xanthophyll cycle pigments at various time scales within these regimes. Our measurements confirmed the PRI linkage to photosynthetic light use efficiency (LUE). However, the strength of this connection was found to be dependent on changing pigment concentrations, specifically on the change in the ratio of chlorophylls to carotenoids. Furthermore, a negative interference in photosynthesis estimation from PRI was recorded if the temperature was lowered overnight to 12 °C. The differential PRI (ΔPRI), calculated as the simple difference between the PRI value measured during the daytime period and in early morning (PRI0), revealed a decreased effect from pigments and cold temperature on LUE estimation. The regression analysis among all measured data identified an increased association between PRI and LUE following the introduction of ΔPRI from R2 = 0. 26 to 0. 69 in beech and from R2 = 0. 61 to 0. 77 in spruce data. The analyses showed that both leaf carotenoid concentrations and the conversion state of xanthophyll cycle pigments played a significant role in determining PRI and PRI0 values and that the accurate assessment of these pigments in PRI across multiple levels of stress from irradiance and temperature might improve estimations of LUE through ΔPRI. In our data, ΔPRI appeared to be a good measure of photosynthesis, the dynamics of which differed between beech and spruce saplings upon switching temperatures.
Grants:	European Commission 610028
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, i la comunicació pública de l'obra, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original. No es permet la creació d'obres derivades.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Subject:	Photochemical reflectance index ; Proximal sensing ; Irradiance ; Temperature ; Carotenoids ; Xanthophyll cycle Light use efficiency
Published in:	Remote sensing of environment, Vol. 244 (July 2020) , art. 111834, ISSN 0034-4257

DOI: 10.1016/j.rse.2020.111834

Postprint 41 p, 838.7 KB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > CREAF (Centre de Recerca Ecològica i d'Aplicacions Forestals) > Imbalance-P
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