A group of biologists led by Ulrike Herzschuh of the Alfred Wegener Institute for Polar and Marine Research (Germany) explained why Siberian coniferous forests have changed little since the Ice Age, although the climate has risen markedly since then. It turned out that the main role was played by permafrost. A press release for the study was posted on the institute's website on Thursday, June 23rd.
The Siberian region is the place on Earth that is most affected by global warming. Today, the temperature conditions in the taiga zone are such that other types of trees, for example, pine and spruce, must grow there. Nevertheless, Siberian larch trees (Larix sibirica) are still found in these places.
Scientists have found that the secret of the anomaly lies in the glaciation, which ended about ten thousand years ago. It turned out that the intensity of the Ice Age determines how quickly vegetation adapts to warmer climates. Since the last cold snap was very severe, taiga tree species lag behind the warming for many thousands of years.
Biologists examined the remains of ancient pollen from the Pliocene and Pleistocene times, preserved in the sediments of Lake Elgygytgyn in Chukotka. Scientists have compared them with the reconstructed parameters of the climate of the warm and cold periods of that time. Statistical analysis revealed a clear picture: it took vegetation several thousand years to adapt to climate change with warming.
During the last glaciation, permafrost spread over very large areas, pushing trees with long roots to the south, while Siberian larches survived under such conditions. The larch forest protects the ice from melting, which slows down the process of replacing plant communities.
Glaciation or ice age is a relative cooling of the climate, which is replaced by warmer interglacials. Many of these cycles make up the Ice Age.