Dynamic of Fluorescence Emissions at O(2)A and O2B Telluric Absorption Bands in Forested Areas with Seasonal APAR and GPP Variations

0567213 - ÚVGZ 2023 RIV CH eng J - Journal Article
Kováč, Daniel - Novotný, Jan - Šigut, Ladislav - Grace, John - Urban, Otmar
Dynamic of Fluorescence Emissions at O(2)A and O2B Telluric Absorption Bands in Forested Areas with Seasonal APAR and GPP Variations.
Remote Sensing. Roč. 15, č. 1 (2023), č. článku 67. E-ISSN 2072-4292
R&D Projects: GA MŠMT(CZ) EF16_019/0000797
Institutional support: RVO:86652079
Keywords : 3-fld * fluorescence * gpp * LiDAR * ndvi * shadow fraction
OECD category: Biophysics
Impact factor: 5, year: 2022
Method of publishing: Open access
https://www.mdpi.com/2072-4292/15/1/67

We measured dynamics of solar-induced chlorophyll fluorescence at telluric oxygen absorption bands O(2)A and O2B in evergreen spruce and deciduous beech forests. Seasonal variations in fluorescence emissions were compared with NDVI. Daily changes in fluorescence emissions were compared with canopy shadow fraction (alpha(S)) dynamics, which showed impact of branch and leaf positions on detected fluorescence signals based on comparison with canopy height model. Absorbed photosynthetically active radiation (APAR) was recognized as a large determinant of fluorescence changes within the O(2)A band (SIFA), with R-2 > 0.68. Fluorescence within the O2B band was more directly linked to NDVI. Although, the seasonal dynamics of fluorescence within the O2B band (SIFB) were similar to SIFA in the spruce forest. In the beech forest, SIFB showed different seasonal dynamics as compared with SIFA. SIFA in the spruce forest showed a relationship to gross primary productivity (GPP), with R-2 = 0.48, and a relationship of R-2 = 0.37 was estimated for the SIFA-GPP connection in the beech forest. SIFB was better linked to seasonal GPP in the beech forest, but with a negative slope in the relationship with R-2 = 0.61. We have shown that measurements of passive fluorescence signals at telluric oxygen absorption bands can contribute to understanding to photosynthesis processes in forest canopies.
Permanent Link: https://hdl.handle.net/11104/0338496