Soil Regeneration, Recovery and Resilience in Carrizo Basin, California: Biomantle Processes Rapidly Overprint Anthropocene Impacts.

Mima mounds are point-centered locally thickened biomantles that, before Anthropocene cultivation, typified many landscapes of North America and the world. Prime examples today are the biogenically produced soil mounds that dot the alluvial fans in the semi-desert adjoined Carrizo and Elkhorn Plains of eastern San Luis Obispo County, California. Carrizo Basin mounds are produced primarily through rodent bioturbation, mainly by kangaroo rats and pocket gophers, augmented by such burrowing predators as badgers, coyotes, foxes and weasels. Some mounded tracts, like those on Elkhorn Plain, were never cultivated. Apart from having been grazed, Elkhorn soils are comparatively virgin and intact in character. Conversely, many mounded tracts on Carrizo Plain were cultivated, with many tens of thousands of mounds historically levelled by the plow. After cultivation ceased in the 1980s, new mounds began reforming on Carrizo Plain largely through bioturbation, and are still forming today, again in the tens of thousands. By visual appearance and morphologically measured attributes, the new mounds are now nearly indistinguishable from the older intact and unplowed Elkhorn Plain mounds.

The biodynamic Carrizo Basin soilscape, and other biodynamic soilscapes examined over a career of field observations and measurements in ecologically diverse environments in the mid-latitudes, subtropics, and tropics, aptly demonstrate the rapidity with which soil biomantles reform and regenerate. The Carrizo Basin soilscape is an ideal ‘then and now’ showcase to demonstrate soil biomantle resilience, recovery and regeneration powered by inexorable ‘healing’ and restorative effects of animal bioturbations. In sum, soil biomantle renewals can rapidly overprint—and quickly erase in less than 40 years—Anthropocene impacts. This fact necessitates thoughtful re-thinking of both soil formation and fallowing processes.