Meteoric Be-10, Cs-137 and Pu239+240 as Tracers of Long- and Medium-Term Soil Erosion-A Review

Isotopes of meteoric Be-10, Cs-137, Pu239+240 have been proposed as a soil redistribution tracer and applied worldwide as an alternative method to classical field-related techniques (e.g., sediment traps). Meteoric Be-10 provides information about long-term soil redistribution rates (millennia), while Cs-137 and Pu239+240 give medium-term rates (decades). A significant progress in developing new models and approaches for the calculation of erosion rates has been made; thus, we provide a global review (n = 59) of research articles to present these three isotopes (meteoric Be-10, Pu239+240 and Cs-137) as soil erosion markers in different environments and under different land-use types. Understanding the dynamics and behaviours of isotopes in the soil environment is crucial to determine their usefulness as soil erosion tracers; thus, we discuss the chemical-physical behaviour of meteoric Be-10, Cs-137 and Pu239+240 in soils. The application of these isotopes sometimes has strong limitations, and we give suggestions on how to overcome them or how to adapt them to a given situation. This review also shows where these isotopic methods can potentially be applied in the future. A lack in knowledge about soil redistribution rates exists particularly in loess-dominated areas where the tillage system has changed or in areas with strong wind erosion.