Biopedoturbation

Biopedoturbation (spelled “biopedturbation” in British, Canadian, and Australian publications) is soil mixing by biological means (i.e., by animals, plants, and humans). Pedoturbation (or “pedturbation”), the mixing of soils, encompasses all forms of biopedoturbation as well as mixing by air, water, shrinking and swelling of clays, freeze-thaw activity, crystal growth, mass movements, extraterrestrial impacts, and earthquakes. Under the broad umbrella of biopedoturbation, “faunalturbation” (also known as “faunalpedoturbation” or “faunalpedturbation”) is the study of soil mixing by animals. Faunalturbation has been widely studied by geographers, compared to the number of geographic studies examining soil mixing by plants, or “floralturbation” (also known as “floralpedoturbation” or “floralpedturbation”). Human mixing of soils, broadly studied in agriculture and pedology as well as in geography, has been referred to as “anthroturbation” (or “anthropedoturbation,” “anthropedturbation”). Biopedoturbation studies are not restricted to geography, where they typically occur within the fields of soils geography and in biogeomorphology, but are also common in pedology and in the ecological subdiscipline of ecosystem engineering. With the increasing focus of geomorphologists on fine-scale process studies and measurements since the 1970s, studies of biopedoturbation have increased dramatically. However, classic studies of biopedoturbation can be traced back to the last published work by Charles Darwin in the late 1800s, who spent his final years meticulously documenting the soil-mixing effects of earthworms. With the emergence of the subdiscipline of zoogeomorphology in the 1990s within geomorphology, many studies of zoogeomorphic effects on landscapes can be considered to fall under the broad rubric of biopedoturbation. Examples include churning of soil by burrowing animals such as gophers and moles, wallowing actions of animals, trampling and chiseling of soils by animal hooves, and digging for food. Floralpedoturbation is primarily accomplished by tree uprooting, although root growth through soils also accomplishes soil mixing. Anthropedoturbation includes all forms of soil mixing by humans, including agricultural activities, and has been invoked by some authors as a primary indicator of the onset of the Anthropocene epoch.