: Impact des activités de charbonnage sur la qualité actuelle des sols forestiers

International audienceNumerous charcoal production sites (CPS) are still present in the vosges forests (Bitcherland, Moselle, France), indicating an intensive use of wood resource in the past. Locally, charcoal residues still form a specific unit at the soil surface. Our work aims to assess the physicochemical properties of current soils impacted by residual charcoals. It complements other research carried out on CPS to reconstruct the history of forest ecosystems and the use of wood resources by humans in the past. First results obtained on two CPS dated from the 19th century, suggest that residual charcoals are not very reactive despite their local abundance. Thus, they do not seem to significantly improve the potential capacity of soils to store nutrients. However, As the charred wood remains layer is thick (around 40cm), the CPS soil seem to store a little more calcium, raising slightly the pH, compared to the soils around. The soil of the two also weakly accumulate more polycyclic aromatic hydrocarbons (PAH). In addition, phenanthrene, the dominant PAH measured in CPS soils, seems to be a relevant marker of charcoal making activities. Micromorphological studies demonstrate that residual charcoals are decomposed by microorganisms and soil fauna, but do not move downwards in the profile. This underlines the absence of earthworms and other soil burrowing organisms. Soils located downhill have similar physico-chemical characteristics than the one uphill (our reference, not affected by CPS charcoal). This suggests very few transfers through subsurface runoff waters.Repetitions of analyses are in progress to confirm these trends. Furthermore, the effect of residual charcoals ageing on soil properties is investigated on an older CPS (from the 17th century). Comparison of all results and first hypothesis on pollutant and nutrient transfers from charcoal mound to trees and to stream water will be formulated. Link to access the video of the communication:https://www.youtube.com/watch?v=TQeXEObtmk