Ground far-red sun-induced chlorophyll fluorescence and vegetation indices in the US Midwestern agroecosystems.

Abstract

Sun-induced chlorophyll fluorescence (SIF) provides an opportunity to study terrestrial ecosystem photosynthesis dynamics. However, the current coarse spatiotemporal satellite SIF products are challenging for mechanistic interpretations of SIF signals. Long-term ground SIF and vegetation indices (VIs) are important for satellite SIF validation and mechanistic understanding of the relationship between SIF and photosynthesis when combined with leaf- and canopy-level auxiliary measurements. In this study, we present and analyze a total of 15 site-years of ground far-red SIF (SIF at 760 nm, SIF 760 ) and VIs datasets from soybean, corn, and miscanthus grown in the U.S. Corn Belt from 2016 to 2021. We introduce a comprehensive data processing protocol, including different retrieval methods, calibration coefficient adjustment, and nadir SIF footprint upscaling to match the eddy covariance footprint. This long-term ground far-red SIF and VIs dataset provides important and first-hand data for far-red SIF interpretation and understanding the mechanistic relationship between far-red SIF and canopy photosynthesis across various crop species and environmental conditions.

Plant phenotyping relevance

作物キャノピーの光合成状態を推定する地上SIFについて、取得データセットと処理・校正・フットプリント拡大プロトコルが中心的に提示されており、植物フェノタイピング手法およびデータセットに該当する。

Code and data availability

The paper's ground far-red SIF760 and vegetation indices dataset (15 site-years, US Corn Belt) is explicitly deposited in a public repository (ORNL DAAC) with a DOI matching an allowed URL.