Terrestrial ecosystems at the P/T-boundary in the Dolomites

The Permian-Triassic ecological crisis in the Dolomites: extinction and recovery dynamics in Terrestrial Ecosytems

Irreversible loss of species is perhaps the most alarming symptom of a possible ongoing mass extinction. In order to understand long-term consequences of present-day biodiversity decline, it is important to investigate past mass extinctions and understand the patterns of species response to global environmental deterioration.

The most severe extinction event of the Earth history happened about 251 million years ago, at the Permian-Triassic boundary. During this event up to 95% of all marine species and about 70% of terrestrial vertebrate species became extinct. Nonetheless, surprisingly little is known about the causes, effects and timing of this mass extinction and successive biotic recovery in terrestrial ecosystems. Our knowledge of the event is mainly based on the study of marine successions in Europe and Asia, while the paucity of continental deposits of the right age restricts the study of terrestrial ecosystems only to the few continuous successions preserved in South Africa, China, Russia, Australia and Antarctica.

The Dolomites are one of the few localities in the world where an integrated study of the different components of the terrestrial ecosystems is possible. An in depth study of this area may, thus, shed new light on the ongoing debates about the causes of mass extinction and its biotic recovery across the Permian-Triassic boundary. Here we propose to study several outcrops from the Late Permian and Early-Middle Triassic from a multidisciplinary point of view integrating the contributions of scientists coming from different academic traditions and areas (palaeobotany, palynology, vertebrate and invertebrate palaeontology, sedimentology, sequence stratigraphy and biostratigraphy). The use of modern and innovative methods and technologies (e.g. multivariate statistic analyses, laser scanner, high-resolution digital photogrammetry, etc.) applied both to the fossils and to the stratigraphical sequences could contribute to reconstruct the evolutionary sequence of terrestrial ecosystems spanning almost 50 million of years across the Permian-Triassic boundary. They will enable to estimate the extinction rate and the tempo and mode of the biotic recovery of different plant and animals groups during and after the catastrophic event.

The obtained data will provide also an important contribution to the worldwide project of the Palaeobiology Database, that constitutes the biggest and most valuable source of online palaeontological data.

The main goal is to gather important clues on the causes and consequences of the end-Permian mass extinction and a better insight on the global pattern of evolution of the terrestrial ecosystems across the Permian-Triassic boundary.