Correction of PRI for carotenoid pigment pools improves photosynthesis estimation across different irradiance and temperature conditions

REMOTE SENSING OF ENVIRONMENT

卷:244

Article

Kovac, Daniel¹  Vesela, Barbora¹  Klem, Karel¹  Vecerova, Kristyna¹  Kmecova, Zuzana Materova²  Penuelas, Josep^1,3,4  Urban, Otmar¹ 

[1] Czech Acad Sci, Global Change Res Inst, Belidla 986-4a, Brno 60300, Czech Republic

[2] Ostrava Univ, Fac Sci, 30 Dubna 22, Ostrava 70103 1, Czech Republic

[3] UAB, Global Ecol Unit, CSIC, CREAF, E-08193 Bellaterra, Catalonia, Spain

[4] CREAF, E-08193 Cerdanyola Del Valles, Catalonia, Spain

关键词: Photochemical reflectance index;    Proximal sensing;    Irradiance;    Temperature;    Carotenoids;    Xanthophyll cycle;    Light use efficiency;   

DOI  :  10.1016/j.rse.2020.111834

来源: Elsevier

【 摘 要 】

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 Delta PRI 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 degrees C. The differential PRI (Delta PRI), 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 Delta PRI from R-2 = 0.26 to 0.69 in beech and from R-2 = 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 Delta PRI. In our data, Delta PRI appeared to be a good measure of photosynthesis, the dynamics of which differed between beech and spruce saplings upon switching temperatures.

【 授权许可】

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