The relationships between selected soil properties and caesium-137 identify organic carbon, nitrogen and water soluble phenols as indicators of soil erosion processes in different forest stands

Abstract

In the last few decades, the use of environmental radionuclides, particularly caesium-137 (137Cs), represented one of the most valid methods for estimating soil erosion. However, the cost associated with the use of the equipment needed for radiometric analyses is still high and, for this reason, finding more easily measurable indicators can be useful. There is a strong correlation between 137Cs, organic carbon (OC), nitrogen (N) and water soluble phenols (WSP) exists, indicating the latter parameters as possible early indicators of soil erosion. Based on the above assumptions, the main purpose of this work is to identify specific soil chemical parameters able to indicate early triggering of soil erosion. Specifically, several soil parameters such as pH, electric conductivity (EC), WSP, OC, N and C/N have been evaluated against 137Cs and on a comparative basis. In addition, since the rate of soil erosion depends on the degree of coverage and canopy structure, two different tree species (Pinus nigra laricio Poir. and Fagus sylvatica L.) have been considered in this contribution in which ten different scenarios of forest management have been analysed. The results show that the reduction in tree cover of managed sites triggers erosion and nutrient loss processes. It has been observed that the loss of 137Cs, compared to the control areas, is closely correlated with those of WSP, OC and N. These parameters (WSP, OC and N), more easily assessable, can be a valid tool to understand easily, triggering of erosive phenomena.