Relation of chlorophyll fluorescence sensitive reflectance ratios to carbon flux measurements of montanne grassland and norway spruce forest ecosystems in the temperate zone
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journal contribution
posted on 2025-01-15, 00:57authored byA Ac, Zbynek Malenovsky, O Urban, J Hanus, M Zitova, M Navratil, M Vrablova, J Olejnickova, V Spunda, M Marek
We explored ability of reflectance vegetation indexes (VIs) related to chlorophyll fluorescence emission (R686/R630, R740/R>800) and de-epoxidation state of xanthophyll cycle pigments (PRI, calculated as (R531 − R570)/(R531 − R570)) to track changes in the CO2 assimilation rate and Light Use Efficiency (LUE) in montane grassland and Norway spruce forest ecosystems, both at leaf and also canopy level. VIs were measured at two research plots using a ground-based high spatial/spectral resolution imaging spectroscopy technique. No significant relationship between VIs and leaf light-saturated CO2 assimilation (AMAX) was detected in instantaneous measurements of grassland under steady-state irradiance conditions. Once the temporal dimension and daily irradiance variation were included into the experimental setup, statistically significant changes in VIs related to tested physiological parameters were revealed. ÄPRI and Ä(R686/R630) of grassland plant leaves under dark-to-full sunlight transition in the scale of minutes were significantly related to AMAX (R2 = 0.51). In the daily course, the variation of VIs measured in one-hour intervals correlated well with the variation of Gross Primary Production (GPP), Net Ecosystem Exchange (NEE), and LUE estimated via the eddy-covariance flux tower. Statistical results were weaker in the case of the grassland ecosystem, with the strongest statistical relation of the index R686/R630 with NEE and GPP.
History
Publication title
The Scientific World Journal
Volume
2012
Issue
1
Article number
705872
Number
705872
Pagination
1-13
ISSN
1537-744X
Department/School
Geography, Planning and Spatial Sciences
Publisher
Hindawi Publishing Corporation
Publication status
Published
Place of publication
410 Park Ave, 15th Fl, PMB 287, NY 1022, US
Rights statement
Licensed under the Creative Commons Attribution 3.0 Unported (CC BY 3.0) http://creativecommons.org/licenses/by/3.0/
Socio-economic Objectives
180601 Assessment and management of terrestrial ecosystems