Drylands soils are being degraded by human activities and climate change, threatening the thin living layers covering their surface, called biocrusts, according to the U.S. Geological Survey. Composed of cyanobacteria, lichens, mosses, algae, fungi and bacteria, biocrusts play major roles in storing carbon, cycling nitrogen, preventing erosion and supporting ecosystems. To better understand the status of these complex biological communities, a team led by researchers at Penn State developed a novel approach for assessing the health and function of biocrusts.
In a study recently published in Remote Sensing in Ecology and Conservation, the team described a method using cameras on drones and multispectral imagery - the analysis of image data across multiple wavelength bands of the electromagnetic spectrum, including invisible radiation like near-infrared, ultraviolet and thermal infrared - to measure pigments created by microorganisms in the soil surface that reveal how healthy or developed the biocrust is.
Even though biocrusts cover only about 12% of Earth's land, they have a disproportionately large ecological impact, according to team leader and senior author Estelle Couradeau, assistant professor of soils and environmental microbiology in the Penn State College of Agricultural Sciences.
