Effective land-based solutions to climate change mitigation require actions that maximize soil carbon storage without generating surplus nitrogen. Land management for carbon sequestration is most often informed by bulk soil carbon inventories, without considering the form in which carbon is stored, its capacity, persistency and nitrogen demand. Here, we present coupling of European-wide databases with soil organic matter physical fractionation to determine continental-scale forest and grassland topsoil carbon and nitrogen stocks and their distribution between mineral-associated and particulate organic matter pools. Grasslands and arbuscular mycorrhizal forests store more soil carbon in mineral-associated organic carbon, which is more persistent but has a higher nitrogen demand and saturates. Ectomycorrhizal forests store more carbon in particulate organic matter, which is more vulnerable to disturbance but has a lower nitrogen demand and can potentially accumulate indefinitely. The share of carbon between mineral-associated and particulate organic matter and the ratio between carbon and nitrogen affect soil carbon stocks and mediate the effects of other variables on soil carbon stocks. Understanding the physical distribution of organic matter in pools of mineral-associated versus particulate organic matter can inform land management for nitrogen-efficient carbon sequestration, which should be driven by the inherent soil carbon capacity and nitrogen availability in ecosystems.

有效的陆上缓解气候变化解决方案要求采取行动，最大限度地提高土壤碳储量，而不会产生多余的氮。碳封存的土地管理通常是通过大量土壤碳清单来了解的，而没有考虑碳的储存形式，容量，持久性和氮需求。在这里，我们介绍了将欧洲范围的数据库与土壤有机物物理分馏结合起来，以确定大陆规模的森林和草地表层土壤碳和氮储量及其在矿物相关和颗粒状有机物库之间的分布。草原和丛枝菌根森林在与矿物相关的有机碳中储存更多的土壤碳，这种碳更持久，但对氮的需求更高并且饱和。外生菌根森林在颗粒状有机物中存储更多的碳，这更容易受到干扰，但对氮的需求较低，并且可能无限期地积累。矿物相关和颗粒有机物之间的碳份额以及碳与氮的比率影响土壤碳储量，并介导其他变量对土壤碳储量的影响。了解矿物相关的有机物与颗粒状有机物池中有机物的物理分布，可以为土地管理提供氮有效的碳固存，这应该由固有的土壤碳容量和生态系统中的氮利用率来驱动。矿物相关和颗粒有机物之间的碳份额以及碳与氮的比率影响土壤碳储量，并介导其他变量对土壤碳储量的影响。了解矿物相关的有机物与颗粒状有机物池中有机物的物理分布，可以为土地管理提供氮有效的碳固存，这应该由固有的土壤碳容量和生态系统中的氮利用率来驱动。矿物相关和颗粒有机物之间的碳份额以及碳与氮的比率影响土壤碳储量，并介导其他变量对土壤碳储量的影响。了解矿物相关的有机物与颗粒状有机物池中有机物的物理分布，可以为土地管理提供氮有效的碳固存，这应该由固有的土壤碳容量和生态系统中的氮利用率来驱动。