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.

海洋磷循环在调节初级生产速率及进而影响海洋生物圈规模方面扮演着至关重要的角色。然而，温度变化——尤其是增温——对海洋磷埋藏的累积效应仍处于理解不足的状态。本研究中，我们探讨了一种底栖生物地球化学模型，该模型考虑了温度对关键成岩反应途径动力学、扩散系数、海水pH值、溶解氧浓度以及生物扰动等复合效应的影响，旨在为理解大陆边缘环境下磷埋藏的温度响应提供一个新的预测框架。研究发现，温度对海洋磷埋藏具有直接且正面的影响，因为它直接增加了关键矿物磷去除途径——尤其是碳酸氟磷灰石（CFA）的形成速率。在气候增温期间，自生磷埋藏的增加可能会部分抵消气候增温事件中水体磷再生速率提高的影响，从而对海洋缺氧和有机物埋藏程度产生影响。在考虑磷循环如何随增温而改变或变化时，这一效应应予以考虑。