Geochemical approach to assessing human impacts in Cork Oak forest soils of the MED region

• Cork oak forest management differs between regions in Europe and North Africa.
• PCA of element patterns in soils identifies 2 to 3 sources in surface soils.
• Parent material, sea salt and canopy/shrub organic matter sources identified
• Minimal chemical impact on cork oak forest soils from human activities found

Cork oak forests in the MED region are of critical social and ecological value and under stress from both environmental change and variation in management practice. This study, as part of a NATO Science for Peace project (SfP 981674), evaluated geochemical methods to assess potentially toxic element (PTE) input to field sites from Quercus suber forests in Tabarka (Tunisia) and an experimental control forest managed by ARGIS-Sardega (Italy). Surface and subsurface soil samples were collected from environmentally comparable sites in the two regions. Sites were identified with varied stand and shrub density and characterised for basic soil properties and multi element content. The data were evaluated using principle component analysis (PCA) and soil enrichment factors (SEF). Soils showed chemical variability associated with differences in parent material and the effects of biomass density. Contributions from events such as fire damage, as well as biomass, sea salt and geogenic sources can be identified, and evaluation is enhanced using a combination of assessment methods. Ultimately despite concerns for the regulation of forest activities in the study area, little direct anthropogenic impact was on soil quality.