A bunch sheep in a valley in the French Alps
Travelart / Alamy
Quick erosion due to human activity, such as grazing of livestock and agriculture, has removed the alps in almost all soil forms withdrawal of glaciers. This soil developed over millennia such as plants, microbes and weather transformed hard rock into the carbon -rich foundation of this mountain ecosystem.
“We destroyed the soil at a speed four to 10 times fases than they grew,” says William Rapuc at the French National Center for Scientific Research.
He and his colleagues studied lithium isotopes in sediments from the Bourget lake in the French Alps to Rempract patterns of earth erosion from the surrounding region for the last 10,000 years. Becuse certain lithium isotopes are enriched as clay and other minerals are formed from mother rock, they can tell you if the earth is developing or eroding, says Rapuc.
They are compared these patterns of soil erosion from the lake’s sediment with other records of changing climate and human activity in the region. In the first several millennia after glaciers, changes in the climate could explain patterns of soil loss. Then, surround 3800 years ago, something changed. “What is not explained by climate … has been explained by the effect of humanity,” says Rapuc.
The researchers identified three waves in soil loss, which they believe they believe corresponds to another type of human activity in the area. Between 3800 to 3000 years ago, the wave came from grazing folding to higher heights. Agriculture at lower heights ran the next wave that happened between 2800 and 1600 years ago, and more intensive agriculture using plows and other tools ran the last climb from 1600 years ago to today. The loss of soil in the Alps accelerates erosion from wind and water, and means that the region has less capacity to support vegetation and crops.
The researchers say this shift 3800 years ago marks the beginning of a “Jord Antopocen” in the region where humans are the dominant influence on land. But this past influence of land “is nothing compared to what we can do now,” says Rapuc.
For example, in the United States, where the Earth Anthropocene started only a few centuries ago, soil losses occur at a speed as much as 1000 times fascins that Daniel Rath before the last glow period, says Daniel Rath in the Natural Resources Defense Council, an environmental lawyer group. “We basically change how land is actually formed and developed because of our agricultural activities.”
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