5/6/2023 0 Comments Iina massiniWe envisage that elevated levels of organic and mineral nutrients delivered from inundated dead forests, enhanced weathering and erosion of extra-basinal areas, together with local contributions of volcanic ash, led to eutrophication and increased salinity of basinal lacustrine-lagoonal environments. The magnitude of the shift at that time records a combination of changes in the global carbon cycle that were enhanced by the local increase in microbial activity, possibly also involving cyanobacterial proliferation. The δ 13 C org values reveal a significant excursion toward low isotopic values, down to −31h (a shift of ∼4h), across the end-Permian event. Based on analogies with modern deforestation, we propose that the global fungal and acritarch events of the Permo-Triassic transition resulted directly from inundation of basinal areas following water-table rise as a response to the abrupt disappearance of complex vegetation from the landscape. The first traces of vascular plant recovery occur ∼1.6 m above the extinction horizon. ![]() Lake systems, expressed by laterally extensive but generally less than a few-metres-thick laminated siltstones, generally lacking bioturbation, hosting assemblages of algal cysts and freshwater acritarchs, developed soon after the vegetation die-off. This signals a catastrophic scenario of vegetation die-off and extinction in southern high-latitude terrestrial settings. We show that the typical Permian temperate, coal-forming, forest communities disappeared abruptly, followed by the accumulation of a 1-m-thick mudstone poor in organic matter that, in effect, represents a 'dead zone' hosting degraded wood fragments, charcoal and fungal spores. We undertook centimeter-resolution palynological, sedimentological, carbon stable-isotope and paleobotanical investigations of strata spanning the end-Permian event at the Frazer Beach and Snapper Point localities, in the Sydney Basin, Australia. The end-Permian mass-extinction event (EPE ∼252 Ma) provides a global, deep-time analogue for modern deforestation and diversity loss. ![]() The tropical forests of the Amazon and Indonesia are currently undergoing deforestation with catastrophic ecological consequences but widespread deforestation events have occurred several times in Earth's history and these provide lessons for the future. The conference also incorporates the Extinction Watch Symposium on Phanerozoic plant/algal extinctions sponsored by the Wenner-Gren Foundation.Ĭurrent large-scale deforestation poses a threat to ecosystems globally, and imposes substantial and prolonged changes on the hydrological and carbon cycles. ![]() The following sections of this book outline the program, symposia and abstracts for over 200 scientific presentations to be given at the 11th European Palaeobotany and Palynology Conference, held jointly by the Swedish Museum of Natural History and Stockholm University from the 19th to 22nd of June, 2022. The third article provides a broader summary of past palaeobotanical work across Sweden and highlights future opportunities for research. The second article provides a short summary of what we argue are the most significant components of the NRM palaeobotany collections, which contain around 400,000 specimens. The first article deals with the historical development of the palaeobotanical research at NRM from its origins in the early 1800s to the present day. The first three sections of this book are intended to provide readers with a understanding of the state of palaeobotany in Sweden and, more specifically, at the Swedish Museum of Natural History (Naturhistoriska riksmuseet: NRM).
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