Increasing Optimum Temperature of Vegetation Activity Over the Past Four Decades

作者：Yiheng Wang, Sangeeta Sarmah, Mrinal Singha, Weinan Chen, Yong Ge, Lìyı̌n Liáng, Santonu Goswami, Shuli Niu · 发表于：Earth s Future · 年份：2024 · DOI：10.1029/2024ef004489 · 被引用次数：21 · 研究领域：Plant Water Relations and Carbon Dynamics、Remote Sensing in Agriculture、Fire effects on ecosystems

Abstract Over the past four decades, global temperatures have increased more rapidly than before, potentially reducing vegetation activity if temperatures exceed the optimum temperature (T opt ). However, plants have the capacity to acclimate to rising temperatures by adjusting T opt , thereby maintaining or even enhancing photosynthesis and carbon uptake. Despite this, it remains unclear how T opt of vegetation activity changes over time and to what extent global vegetation can acclimate to current temperature changes. In this study, we evaluated the temporal trends of T opt of vegetation activity and the thermal acclimation magnitudes globally using three remote‐sensed vegetation indices and eddy‐covariance observations of gross primary productivity from 1982 to 2020. We found that the global T opt of vegetation activity has increased at an average rate of 0.63°C per decade over the past four decades. The increase in T opt closely tracked the rise in annual maximum daily mean temperature (T max ), indicating that thermal acclimation has occurred widely across the globe. Globally, we found an average thermal acclimation magnitude of 0.38°C per 1°C increase in T max . Notably, polar and continental regions exhibited the highest thermal acclimation magnitudes, while arid areas showed the lowest. Additionally, the thermal acclimation magnitude was positively affected by interannual temperature variability and negatively affected by soil moisture and vapor pressure deficits. Our...