Winter leaf reddening and photoprotection accessed by vegetation indices and its influence on canopy light-use efficiency of a Japanese cypress (Chamaecyparis obtusa) forest

作者：Siyu Chen, Yoshiko Kosugi, Linjie Jiao, Ayaka Sakabe, Daniel Epron, Tatsuro Nakaji, Hibiki Noda, Kouki Hikosaka, Kenlo Nishida Nasahara · 发表于：Agricultural and Forest Meteorology · 年份：2025 · DOI：10.1016/j.agrformet.2025.110427 · 被引用次数：7 · 研究领域：Remote Sensing in Agriculture、Plant Water Relations and Carbon Dynamics、Horticultural and Viticultural Research

• Canopy-scale VIs used to track winter leaf reddening in Japanese cypress. • The relationship evaluated between VIs and canopy-scale LUE. • VIs could detect the phenology and LUE changes during winter leaf reddening. • Winter leaf reddening is driven by prolonged low temperatures. Japanese cypress ( Chamaecyparis obtusa Sieb . et Zucc.) is an evergreen conifer native to Japan and widely distributed in East Asia. Evergreen forests in temperate regions are usually exposed to high solar radiation and low temperatures during winter, a combination of stresses that can negatively impact leaf photosynthetic capacity. In response to excessive light energy stress under cold temperatures, Japanese cypress canopies exhibit a reversible color change associated with several photoprotective mechanisms known as “winter leaf reddening.” Here, several vegetation indices (VIs), including the photochemical reflectance index (PRI), rhodoxanthin index (RI), chlorophyll/carotenoid ratio index (CCI), triangular PRI index (tri-PRI), and red-green vegetation index (RGVI) were utilized to track the influence of winter leaf reddening and photoprotection on canopy-scale light-use efficiency (LUE) determined by the eddy covariance technique. Seasonal changes in VIs, environmental factors, and LUE in Japanese cypress canopies between 2017 and 2021 indicated that VIs could detect the phenology and LUE changes during winter leaf reddening. Our results suggest that winter leaf reddening occurrence is driven...