The area of ​​Tenagi Philippi, in eastern Macedonia, is one of the few global reference points for climate change, providing information on the changes that occurred in the region over a million years. A team of researchers from universities and research centers in Germany, France, Britain and Greece studied fossilized pollen collected at the site and raised the alarm about possible desertification threatening the forests of the Mediterranean.

The bog (marsh) in Tenagi Philippi he is unique. It is the deepest in the world, with a thickness of about 170 meters corresponding to a deposit of peat over the last 1,300,000 years. It is therefore a rare climate record, one of the few global reference points for terrestrial environments related to climate change.

Speaking to APE-MBE, the Greek researcher of the Department of Geosciences of the University of Heidelberg, Andreas Koutsodendris, likens the Philippi Tenagi to a large History book, where each centimeter of peat corresponds to a page with information about changes in the vegetation and climate of the area. “Most regions give us information for a few hundred or a few thousand years. The unique thing about the Tenagi Philippi region is that we have a climate record that goes back in time and is unique. It is about the history that has been recorded there for the last 1.3 million years“, he says characteristically.

A team of scientists, led by the University of Heidelberg and Mr. Koutsodendris, is conducting in the area research for almost 20 yearsaiming to record the changes in the region’s ecosystem over time, valuable information for its sustainability in the future.

This area was chosen for another reason. The climate in the Philippi Islands is representative for the dry areas of the Mediterranean, i.e. for two-thirds of the Mediterranean basin which is estimated at about 76 million hectares. So the researchers’ estimates of the changes in the climate here also concern the largest percentage of the Mediterranean ecosystems.

The object of study was pollen, which, as Mr. Koutsodendris explains, if found in the right environment, can be preserved for millions of years in the sediments and provide important information about the vegetation and therefore the climate of the past.

The research team focused on the upper 90 meters of the peat, which corresponds to about the last 500,000 years of the area’s history. After drilling to collect sediments, the scientists studied about 2,500 pollen samples preserved in sediments of different depths to trace changes in climate and vegetation during this period.

The samples selected have a time distance between them of about 200 years, while in some cases the time difference is only 80 years, so that the vegetation and its changes during these 500,000 years can be studied with great precision.

The data from the pollen study was correlated with geochemical analyzes of the peat, the chemical composition of which changes according to the climate of each season, recording in detail changes in precipitation levels. The obtained results show that in the past, once the rainfall fell to low limits, the Mediterranean forests turned into steppes very quickly, within only a few decades.

They also found that the amount of rainfall in the Mediterranean region was affected by changes in the carbon dioxide content of the atmosphere, a fact that is particularly worrying today when, as the Heidelberg University researcher explains, the concentration of carbon dioxide in the atmosphere is considered the longer than the last 4.5 million years.

“Because Mediterranean forests are highly sensitive to climate change, concern for their survival is growing in light of anthropogenic carbon dioxide emissions and consequent global warming“, Mr. Koutsodendris emphasizes to APE-MPE.

The above information combined with the specialized climate models that scientists have in their hands warn of a dramatic decrease in rainfall and therefore possible desertification of the Mediterranean forests in the near future.

The scientists underline that in such a case, the disappearance of the Mediterranean forests will not happen gradually but at a very rapid pace, which is why targeted forest management interventions are needed to make them more resilient.

In the research, published in the journal Nature Communications, a large group of research bodies is involved. From Greece, the Geology Department of the University of Patras is participating with Professor Kimonas Christanis. Also taking part are the Institute of Evolutionary Sciences of the University of Montpellier with the Greek researcher Vassilis Dakos, the School of the Environment of the University of Manchester, the Department of Molecular Botany of the University of Hohenheim, the Institute of Geology of the University of Hamburg, the Department of Geography of the University Royal Holloway, London, the Schenkenberg Center for Biodiversity and Climate Research in Frankfurt and the School of Environment, Geography and Geosciences, University of Portsmouth.