Soil bioturbation – how habitat climatic constraints shape biophysical processes

Soil bioturbation is the physical movement and alteration of soil by fauna and plants. It plays a central role in soil formation at long time scales and shapes soil structure at hydrologic time scales that affects many soil physical processes and ecosystem services. Varying biomes act as hosts to a variety of ‘ecosystem engineers’ that have developed unique strategies for generating habitats and appreciable soil biopores. For example, earthworms and plant roots generate biopores in moist soil via penetration-expansion (and some ingestion) processes. Other organisms such as ants or termites excavate soil by displacing soil particles with their limbs. We present an overview of biophysical processes associated with soil bioturbation driven by various biological agents and biomechanical  strategies (e.g. penetrators vs excavators). The study highlights the critical role of soil moisture and texture in modulating and shaping the various biomechanical strategies and activity time windows. We explore the implications that regional environmental factors play in locally favoring particular bioturbation processes, which can be used to identify the likelihood of a specific bioturbation agents occurrence in a given region. The overview highlights the relative impact of soil bioturbation on soil structure formation by comparison with conventional tillage processes (restricted to arable lands). Ultimately, this work endeavors to open discussions that can aid in reducing intensive mechanized tillage and help guide sustainable land use initiatives by capitalizing on the biological agents present in the environment.