Ranches and Agriculture Deplete Nearly All Soil in the Alps

Intensive erosion driven by human activities like livestock grazing and farming has nearly completely removed the soil that formed in the Alps since the glaciers receded. This soil, shaped over millennia by plants, microorganisms, and the elements, established the carbon-rich foundation for the mountains’ ecosystems.

“We’ve depleted it at a rate four to ten times greater than its natural regrowth,” states William Lupook from the French National Center for Science and Research.

He and his team investigated lithium isotopes in sediment collected from Lake Burgette in the French Alps to trace soil erosion patterns in the area over the last 10,000 years. The presence of specific lithium isotopes indicates the formation of clays and other minerals from the original rock, facilitating the determination of whether soil is accumulating or being lost, according to Rapuc.

The sediment erosion patterns were analyzed alongside records of local climate variations and human influence. In the first thousand years post-glacier retreat, climate change could explain soil loss. However, around 3,800 years ago, a notable shift occurred. “What climate factors cannot explain must be attributed to human impacts,” Rapuc notes.

The researchers pinpointed three distinct periods of increased soil loss, each linked to various human activities. From 3,800 to 3,000 years ago, the surge was associated with high-intensity grazing. The next surge, seen between 2,800 and 1,600 years ago, was driven by agriculture at lower elevations, while the most recent increase—from 1,600 years ago to the present—corresponds to more advanced agricultural practices, including plowing. This ongoing soil loss in the Alps exacerbates erosion caused by wind and water, decreasing the area’s capacity to support vegetation and crops.

Researchers assert that this transition marks the advent of the “Soil Anthropocene” era, a time when human impact on soil became prevalent 3,800 years ago. However, according to Rapuc, the past consequences on soil pale in comparison to our current capabilities for disruption.

For instance, in the United States, where the effects of the Soil Anthropocene began centuries ago, soil is being lost at a startling rate—1,000 times faster than prior to the last ice age, explains Daniel Lass from the Natural Resources Defense Council, an environmental advocacy organization. “We are fundamentally altering the natural processes of soil formation and development due to agricultural practices.”