The researchers will study plants, early four-limbed vertebrates and sediments from the transition between the Devonian and Carboniferous periods – two geological periods during which the first large forest ecosystems developed on land. The aim is to increase understanding of how plants, animals and ecosystems responded to climate change around 360 million years ago.

A unique place for understanding Earth’s early ecosystems

Bear Island lies between mainland Norway and Svalbard and is one of the few places where sediments from the Devonian, Carboniferous and Permian periods are well preserved and accessible for research.

– The geological successions are exceptional. There is no vegetation on Bear Island, which means the successions are clearly visible and relatively accessible once you get there, says Vivi Vajda, Professor and Head of Palaeobiology at the Swedish Museum of Natural History.

In many other parts of the world, equivalent sediments are difficult to study or are absent altogether. The combination of well-preserved sediments and the lack of vegetation makes Bear Island an unusually valuable site for research on Earth’s early terrestrial ecosystems.

The researchers want to investigate how plant communities changed during the period when landscapes transitioned from rainforest environments to more extensive swamp ecosystems. A key question is why these changes occurred. Were they linked to the mass extinction that affected marine life during the Late Devonian, or were they part of a more gradual ecological transition driven by climate change?

– We know that a major mass extinction occurred in the oceans during the Late Devonian. Now we want to better understand what happened on land.

The team will document sediments and fossil discoveries while investigating how plant and animal communities developed during this period.

Plants, early land animals and climate change

A large part of the expedition will focus on plant fossils. During the Late Devonian, ferns evolved, and during the Carboniferous the first seed plants appeared. The research team will also search for fossils of early tetrapods – the first four-limbed vertebrates to live on land.

– We hope to gain more knowledge about the evolution of early land plants, but equally important is the evolution of early land animals and how plants and animals interacted, says Vivi Vajda.

The researchers also hope to build upon earlier collections from Bear Island housed at the Swedish Museum of Natural History. Many of these fossils were collected during previous expeditions, but information about their stratigraphic position is missing.

– We do not know exactly where in the succession the fossil plants were found. That information is extremely important for those of us studying ecosystem dynamics, and it is something we can now document.

Although the research focuses on events that took place hundreds of millions of years ago, the findings remain relevant today. By studying fossil plants, pollen and spores, the researchers can investigate how vegetation responded to changes in temperature, precipitation and atmospheric carbon dioxide levels.

During the Devonian and Carboniferous periods, extensive forests developed and removed large amounts of carbon dioxide from the atmosphere. As plant material became buried, coal deposits eventually formed, contributing to a reduction in atmospheric carbon dioxide.

– By understanding these processes, researchers can better explain the relationship between vegetation, carbon storage and climate change today.

Research in a demanding environment

Fieldwork on Bear Island involves long hikes through unfamiliar terrain, living in tent camps and transporting fossil material to the coast for shipment by vessel. The expedition must also be prepared for the possibility of encountering polar bears.

– All the support we receive from the Swedish Polar Research Secretariat in terms of travel, experienced personnel and logistics is absolutely crucial to the expedition. We simply could not carry it out without the knowledge, experience and equipment they provide.

If the expedition were to produce a true dream discovery, Vivi Vajda knows exactly what she would hope to find.

– The missing link between ferns and the first seed plants. A plant representing a transitional form.

In the longer term, the researchers hope the expedition will contribute new knowledge about how plants colonised land and how ecosystems developed in response to climate change throughout Earth’s history.

– We also want the public to gain a better understanding of how closely connected climate, life and Earth’s history really are, says Vivi Vajda.