The influence of warming on phosphorus burial in continental margin sediments

The marine phosphorus cycle plays a critical role in regulating rates of primary productivity and, thus, the size of the marine biosphere. Yet, the cumulative effects of temperature change—and warming, in particular—on marine phosphorus burial remain poorly understood. Here, we explore a benthic biogeochemical model that accounts for the compounded effect of temperature on the kinetics of key diagenetic reaction pathways, diffusion coefficients, seawater pH, dissolved O2 concentration and bioturbation, in order to provide a new predictive framework for understanding the temperature response associated with P burial in continental margin settings. We find that temperature has a direct and positive impact on marine phosphorus burial, as it directly increases the formation rate of key mineral P-removal pathways—foremost carbonate fluorapatite (CFA). The increase in authigenic P burial during climate warming is likely to partially counter the effects of increased water-column P regeneration rate during climate warming events, and thus have an impact on the extent of oceanic anoxia and organic matter burial and should be considered when considering the how P cycle changed or will change in the face of warming.海洋磷循环在调控初级生产力速率，进而调控海洋生物圈规模方面发挥着至关重要的作用。然而，温度变化（尤其是全球增温）对海洋磷埋藏的累积效应仍未得到充分认知。本研究构建了一款底栖生物地球化学模型，该模型可量化温度对关键成岩反应路径动力学、扩散系数、海水pH、溶解氧浓度以及生物扰动的复合效应，旨在为理解大陆边缘环境中磷埋藏的温度响应提供全新的预测框架。研究发现，温度对海洋磷埋藏具有直接且正向的调控作用：其可直接提升关键矿物除磷路径的形成速率，其中最主要的为碳氟磷灰石（carbonate fluorapatite, CFA）。气候变暖过程中自生磷埋藏量的提升，可部分抵消升温事件下水柱磷再生速率升高带来的影响，进而对海洋缺氧范围与有机质埋藏量产生调控效应。因此，在探讨全球变暖背景下磷循环的历史变化与未来趋势时，需将该效应纳入考量范畴。