Enhanced terrestrial nutrient release during the Devonian emergence and expansion of forests: Evidence from lacustrine phosphorus and geochemical records

The evolution of land plant root systems occurred stepwise throughout the Devonian, with first evidence complex appearing in mid-Givetian. This biological innovation provided an enhanced pathway for transfer terrestrial phosphorus (P) to marine system via weathering and erosion. enhancement is consistent paleosol records has led hypotheses about causes eutrophication mass extinctions during Devonian. To gain insight into transport P between domains, we report geochemical from a survey Middle Late Devonian lacustrine near-lacustrine sequences that span some these key extinction intervals. Root hypothesized have delivery, results multiple Euramerica show net loss sources coincident appearance early progymnosperms. Evidence sites Greenland northern Scotland/Orkney reveal near-identical P. Additionally, all are temporally proximal one or more events, including precise correlation Ka?ák event two pulses associated Frasnian/Famennian extinction. For sites, weathering, climate, redox proxy data, coupled nutrient input variability, similar responses as seen extant systems. Orbitally forced climatic cyclicity appears be catalyst significant pulses, which suggests expansion plants may tied variations regional global climate.