Boreal conifers maintain carbon uptake with warming despite failure to track optimal temperatures

作者：Mirindi Eric Dusenge, J. M. Warren, Peter B. Reich, Eric J. Ward, Bridget Murphy, Artur Stefański, Raimundo Bermúdez, Marisol Cruz, David McLennan, A. W. King, Rebecca Montgomery, Paul J. Hanson, Danielle A. Way · 发表于：Nature Communications · 年份：2023 · DOI：10.1038/s41467-023-40248-3 · 被引用次数：31 · 研究领域：Plant responses to elevated CO2、Plant Water Relations and Carbon Dynamics、Tree-ring climate responses

Abstract Warming shifts the thermal optimum of net photosynthesis ( T optA ) to higher temperatures. However, our knowledge of this shift is mainly derived from seedlings grown in greenhouses under ambient atmospheric carbon dioxide (CO 2 ) conditions. It is unclear whether shifts in T optA of field-grown trees will keep pace with the temperatures predicted for the 21 st century under elevated atmospheric CO 2 concentrations. Here, using a whole-ecosystem warming controlled experiment under either ambient or elevated CO 2 levels, we show that T optA of mature boreal conifers increased with warming. However, shifts in T optA did not keep pace with warming as T optA only increased by 0.26–0.35 °C per 1 °C of warming. Net photosynthetic rates estimated at the mean growth temperature increased with warming in elevated CO 2 spruce, while remaining constant in ambient CO 2 spruce and in both ambient CO 2 and elevated CO 2 tamarack with warming. Although shifts in T optA of these two species are insufficient to keep pace with warming, these boreal conifers can thermally acclimate photosynthesis to maintain carbon uptake in future air temperatures.