The uptake of carbonyl sulfide (OCS) by vegetation is reasonably well understood scaling down from the atmosphere to the biological metabolism based on the enzymatic consumption. As all enzymes are closely involved in the exchange of OCS and of carbon dioxide (CO2) as well, there is a closely related uptake of CO2 and OCS, the latter being unidirectional. Thus, we face an ongoing discussion exploiting the uptake of COS as a proxy to estimate Gross Primary Productivity (GPP). However, there may be influential unknowns to the overall exchange of OCS between vegetated Areas and the atmosphere. This meeting will deal with these issues.