1. Reflections of stress: Ozone damage in broadleaf saplings can be identified from hyperspectral leaf reflectance.
- Author
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Lee Jones, Anna, Ormondroyd, Adam, Hayes, Felicity, and Jeffers, Elizabeth S.
- Subjects
AIR pollution monitoring ,TROPOSPHERIC ozone ,REFLECTANCE spectroscopy ,TEMPERATE forests ,SPECTRUM analysis ,ALNUS glutinosa - Abstract
Tropospheric ozone (O 3) causes widespread damage to vegetation; however, monitoring of O 3 induced damage is often reliant on manual leaf inspection. Reflectance spectroscopy of vegetation can identify and detect unique spectral signatures of different abiotic and biotic stressors. In this study, we tested the use of hyperspectral leaf reflectance to detect O 3 stress in alder, beech, birch, crab apple, and oak saplings exposed to five long-term O 3 regimes (ranging from daily target maxima of 30 ppb O 3 to 110 ppb). Hyperspectral reflectance varied significantly between O 3 treatments, both in whole spectra analysis and when simplified to representative components. O 3 damage had a multivariate impact on leaf reflectance, underpinned by changes in pigment balance, water content and structural composition. Vegetation indices derived from reflectance which characterised the visible green peak were able to differentiate between O 3 treatments. Iterative normalised difference spectral indices across the hyperspectral wavelength range were correlated to visual damage scores to identify significant wavelengths for O 3 damage detection. We propose a new Ozone Damage Index (OzDI), which characterises the reflectance peak in the shortwave infrared region and outperformed existing vegetation indices in terms of correlation to O 3 treatment. These results demonstrate the potential application of hyperspectral reflectance as a high throughput method of O 3 damage detection in a range of common broadleaf. species. [Display omitted] • Tropospheric ozone damage changes leaf reflectance of broadleaf saplings. • The hyperspectral reflectance signal of ozone damage is multivariate. • This signal has the potential be scaled up for monitoring ozone damage to forests. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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