Norway – Researchers from the United Kingdom have found ancient fossil forests, that are believed to have played an important role in the massive climate change on Earth during the Devonian period, about 400 million years ago.
A team from Cardiff University uncovered a series of preserved tree stumps in Svalbard, a Norwegian archipelago in the Arctic Ocean, as scientists believe that the forest could explain the 15-fold reduction in carbon dioxide levels in the atmosphere at that time. Svalbard was located at the equator, before the tectonic planet drifted towards north by 80 degrees to its current position.
Professor John Marshall, of Southampton University, determined the forests existed 380 million years ago. These forests grew near the equator in the late Devonian period (420-360 million years ago), and researchers believe that a change in vegetation -from tiny plants to large forest trees- caused the CO2 levels’ drop in the atmosphere.
“The evolution of tree-sized vegetation is the most likely cause of this dramatic drop in carbon dioxide because the plants were absorbing carbon dioxide through photosynthesis to build their tissues, and also through the process of forming soils,” Dr. Chris Berry explained in a press release.
By the process of photosynthesis -by which the plants create food and tissues- the CO2 is pulled out of the air. Although large trees absorb more of the sun’s radiation, it is believed that temperatures on Earth have also dropped to low levels due to the reduction in atmospheric CO2. High temperatures and large rates of rainfall on the equator show that forests contributed the most to these changes.
Dr. Berry, who discovered and described these fossils, explained that they show us what the vegetation and landscape were like 360 million years ago in the equator, a moment where the first trees began to appear on the Earth.
The research team found that the forest in this region was formed mostly of lycopod trees, trees that million years later grew in coal swamps -eventually turning into coal deposits, such as the ones in South Wales. Moreover, they found that these forests were very dense, having very small gaps -around 20cm between each three- and trees probably reached the 4m high.
Dr. Berry has previously worked in collaboration with U.S. researchers, describing a slightly older forest located at New York’s Gilboa. This forest was previously situated 30 degrees south of the equator during the Devonian Period, as they discovered several tree stumps that belong to different plant species.
Svalbard is today one of the freezing-cold regions in the north that are inhabited by men, home of just 2,500 of them. Also, it is the home of the “Global Seed Vault,” an underground seed bank that contains a large range of seeds in case a huge crisis or tragedy results in the loss of the vegetation diversity on Earth.
Source: Journal Geology