Seasonal variation in the canopy color of temperate evergreen conifer forests

Bibliographische Detailangaben
Veröffentlicht in:	The New phytologist. - 1979. - 229(2021), 5 vom: 29. März, Seite 2586-2600
1. Verfasser:	Seyednasrollah, Bijan (VerfasserIn)
Weitere Verfasser:	Bowling, David R, Cheng, Rui, Logan, Barry A, Magney, Troy S, Frankenberg, Christian, Yang, Julia C, Young, Adam M, Hufkens, Koen, Arain, M Altaf, Black, T Andrew, Blanken, Peter D, Bracho, Rosvel, Jassal, Rachhpal, Hollinger, David Y, Law, Beverly E, Nesic, Zoran, Richardson, Andrew D
Format:	Online-Aufsatz
Sprache:	English
Veröffentlicht:	2021
Zugriff auf das übergeordnete Werk:	The New phytologist
Schlagworte:	Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. AmeriFlux PRI PhenoCam evergreen conifer phenology seasonality xanthophyll

Beschreibung
Zusammenfassung:	© 2020 The Authors New Phytologist © 2020 New Phytologist Foundation. Evergreen conifer forests are the most prevalent land cover type in North America. Seasonal changes in the color of evergreen forest canopies have been documented with near-surface remote sensing, but the physiological mechanisms underlying these changes, and the implications for photosynthetic uptake, have not been fully elucidated. Here, we integrate on-the-ground phenological observations, leaf-level physiological measurements, near surface hyperspectral remote sensing and digital camera imagery, tower-based CO2 flux measurements, and a predictive model to simulate seasonal canopy color dynamics. We show that seasonal changes in canopy color occur independently of new leaf production, but track changes in chlorophyll fluorescence, the photochemical reflectance index, and leaf pigmentation. We demonstrate that at winter-dormant sites, seasonal changes in canopy color can be used to predict the onset of canopy-level photosynthesis in spring, and its cessation in autumn. Finally, we parameterize a simple temperature-based model to predict the seasonal cycle of canopy greenness, and we show that the model successfully simulates interannual variation in the timing of changes in canopy color. These results provide mechanistic insight into the factors driving seasonal changes in evergreen canopy color and provide opportunities to monitor and model seasonal variation in photosynthetic activity using color-based vegetation indices
Beschreibung:	Date Completed 14.05.2021 Date Revised 05.10.2022 published: Print-Electronic Citation Status MEDLINE
ISSN:	1469-8137
DOI:	10.1111/nph.17046