Beyond the visible: Accounting for ultraviolet and far‐red radiation in vegetation productivity and surface energy budgets

作者：Yujie Wang, Renato K. Braghiere, Yi Yin, Yitong Yao, Dalei Hao, Christian Frankenberg · 发表于：Global Change Biology · 年份：2024 · DOI：10.1111/gcb.17346 · 被引用次数：10 · 研究领域：Remote Sensing in Agriculture、Plant Water Relations and Carbon Dynamics、Plant responses to elevated CO2

Abstract Photosynthetically active radiation (PAR) is typically defined as light with a wavelength within 400–700 nm. However, ultra‐violet (UV) radiation within 280–400 nm and far‐red (FR) radiation within 700–750 nm can also excite photosystems, though not as efficiently as PAR. Vegetation and land surface models (LSMs) typically do not explicitly account for UV's contribution to energy budgets or photosynthesis, nor FR's contribution to photosynthesis. However, whether neglecting UV and FR has significant impacts remains unknown. We explored how canopy radiative transfer (RT) and photosynthesis are impacted when explicitly implementing UV in the canopy RT model and accounting for UV and FR in the photosynthesis models within a next‐generation LSM that can simulate hyperspectral canopy RT. We validated our improvements using photosynthesis measurements from plants under different light sources and intensities and surface reflection from an eddy‐covariance tower. Our model simulations suggested that at the whole plant level, after accounting for UV and FR explicitly, chlorophyll content, leaf area index (LAI), clumping index, and solar radiation all impact the modeling of gross primary productivity (GPP). At the global scale, mean annual GPP within a grid would increase by up to 7.3% and the increase is proportional to LAI; globally integrated GPP increases by 4.6 PgC year −1 (3.8% of the GPP without accounting for UV + FR). Further, using PAR to proxy UV could overestimate ...