Abstract. Present-day lake water phosphorus (P) enrichment and accelerated P cycling are changes superimposed on a dynamic Holocene history of
landscape development following glaciation, changes in climate, and long-term low-intensity human activity. Knowledge of the history of long-term
P dynamics is essential for understanding present-day landscape P export and for managing both terrestrial and aquatic
environments. This study is the first attempt to constrain the timing and magnitude of terrestrial changes in Holocene P dynamics across the
Northern Hemisphere using lake sediment records. Here we reconstruct trajectories in terrestrial Holocene P dynamics for the Northern Hemisphere. We apply a simple process model to published
lake sediment geochemical P records from 24 sites, producing records of landscape P yield and reconstructing lake water total
phosphorus (TP) concentrations. Individual site trajectories of landscape P yield and lake water TP vary systematically, with differences
attributable to local landscape development history. Three distinct traits are apparent. Mountain sites with minimal direct human impact show
falling P supply and conform to conceptual models of natural soil development (Trait 1). Lowland sites where substantial (pre-)historic
agriculture was present show progressively increasing P supply (Trait 2). Lowland sites may also show a rapid acceleration in P supply
over the last few centuries, where high-intensity land use, including settlements and farming, is present (Trait 3). Where data availability
permitted comparison, our reconstructed TP records agree well with monitored lake water TP data, and our sediment-inferred P yields are
comparable to reported catchment export coefficients. Comparison with diatom-inferred TP reveals good agreement for recent records. Our reconstructions form the first systematic assessment of average terrestrial P export for the Northern Hemisphere over the Holocene and
provide the empirical data needed for constraining long-term landscape P cycling models and values for terrestrial P export that could
be used for ocean P cycling models. The long-term perspective provided by our sediment-inferred TP can be used to identify pre-disturbance
baselines for lake water quality, information essential to target-driven lake management. We find the first detectable anthropogenic impacts on
P cycling ca. 6000 BP, with more substantial impacts as early as 3000 BP. Consequently, to characterize pre-disturbance lake P
conditions at Trait 2 and Trait 3 sites, it is necessary to consider time periods before the arrival of early farmers. Our use of trait
classifications has a predictive power for sites without sediment records, allowing prediction of TP baselines and P trajectories based on
regional landscape development history.