More dust: soil crusts under climatic stress

A thin layer of microbes, moss, and algae covers about a quarter of the dryland soil area; Visually blurred biological soil crusts, also called biocrusts, cover about one-eighth of the global Earth’s surface.

Although these communities are only found in the upper millimeters of soil, they contribute significantly to the biogeochemical nutrient cycle, act as nitrogen and carbon sources, and improve soil water balance and plant growth, according to the research team led by Emilio Rodriguez Caballero. From the University of Almeria, Spain arrested. Above all, they also increase the stability of the soil.

How do crusts affect the dust cycle?

The largest biosphere regions are found in Africa, the Middle East, Asia, Australia, and the American Midwest. The extent to which these crusts affect the atmospheric dust cycle was previously unknown – and this research team has now modeled on a global scale.

The researchers combined measurement data from biological soil crusts with a global climate model, calculating their current significance and simulating different future scenarios. They recognized that biodust significantly reduces global dust emissions and sediments: “We estimate that all events together reduce global atmospheric dust pollution by about 60 percent,” says Bettina Weber, a biologist at the University of Graz and co-author of the publication. However, when dry soil loses its stability through loss of soil crust, it undergoes erosion, sand and wind are released into the atmosphere.

Up to 15 percent more dust

If biodust loss from climate change and land use intensification is as high as expected, researchers expect global dust pollution to increase by as much as 15 percent in 2070. As a result, more dust enters the atmosphere, with various impacts. According to the authors, it can be assumed that bio-dust influences the climatic effects of dust in a similar way to the direct influence of aerosols from human activity.

“The main player in global change”

The impact of biodust on the global dust cycle and attendant climatic consequences have important implications for the health, biogeochemical cycle and functioning of ecosystems. The authors consider it necessary to consider biogassing as key players in global change and recommend that they be considered in modeling future global change, mitigating measures for current climate evolution and designing adaptation strategies.