Arid Europe

2000/02/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Geologia

In a distant time, thanks to its tropical climate, the giant coniferous forests dominated the European lands. But 250 million years ago, in the massive destruction of Permiar, they disappeared completely and did not return until 5 million years later. And that is what surprises paleontologists, who for so long have disappeared.

The extinction of the Permian destroyed 95% of the species then, but the causes of extinction remain undiluted, although paleontologists know that something unbalanced the ecosystem for hundreds of thousands of years. Probably due to the greenhouse effect, the sea level decreased and the temperature increased. Huge volcanic explosions launched 2 million cubic kilometers of lava. Lava covered much of Siberia and could be responsible for the extinction of some species.

The Persian destruction was greater than that of dinosaurs and
plants took much longer to reappear. The licopod is a plant of the moss group, with a trunk without branches of leaves and a cone full of spores at the top. Their initial height was 10 or 20 cm, but they reached 2 m. Like plants that reproduce with spores, they need a humid medium to reproduce and paleontologists have deduced that they lived on the banks of rivers or currents.

With the reappearance of conifers in Europe, the regeneration of temperate and dry forests took half a million years. Often, considering that, after the last glaciation, the forests of northern Europe reappeared in a few millennia. Researchers believe that plants had to fight some toxic substance, such as sulfur gases from volcanoes.