Elemental characterisation of native lichens collected in an area affected by traditional charcoal production

This study provides a seasonal elemental characterisation of native lichens collected in rural areas of Portugal affected by charcoal kilns, using nuclear analytical techniques and electric conductivity. In autumn, it was possible to identify high levels of electric conductivity near the site with charcoal kilns due to higher oxidative stress of the lichens' membrane. Typical chemical elements associated with emissions of wood burning, such as S and P, also presented the highest contents near the charcoal kilns. However, the same phenomenon was not found in spring. Residential areas presented the highest levels of S and P probably due to the impact of biomass burning from home heating that occurred during the winter period. Overall, lichens were found to be enriched with elements that can be attributable to non-crustal sources, namely, sea salt spray (Cl and Na), fertilisers used in agriculture (P and Ca) and wood burning (P and S).