1. What have we done after the meeting in Turkey? 1.León was divided into four areas within a 3 km radius from the city centre. Three trees were selected in each area. 2.Lichen samples were taken from the twelve selected trees.

2. León satellite picture with the selected trees

3. Our working method 3.An Identification Key was designed to facilitate the subsequent fieldwork. 4.A plastic sheet was used. The plastic sheet was placed on the tree bark. The presence of the different species of lichens was marked with coloured felt-tip pens.

9. Calculation of Values 5.Two values were calculated for each area from the collected data: – IBL (Indice de Biodiversidad Liquénica or Lichenic Biodiversity Index): (to calculate the lichen frequency) – I2C (to measure the total area occupied by lichens) 6.Data were organized in an excel sheet and conclusions were drawn up.

10. Summary Chart of IBL-I2C in León

11. Conclusion Pollution levels are higher in the West than in the North and East. Tendency is similar for both values. Pollution levels in all the 4 areas (a ring of 2- 3 km from the city centre) are low or very low.

12. Second study area 7.A second sampling area was selected: Monte San Isidro, an oak park and recreation area 5 km away from Leon. 8.Six trees were selected in this area.

13. Satellite picture of León and Monte S.Isidro

14. Position of Selected trees in Monte San Isidro

15. One Selected oak tree in Monte S.Isidro

16. What are we going to do this year? 9.Sampling and value calculation of the six trees in Monte San Isidro. 10.At our Secondary Education School (LegioVII), students are working on the paper cycle. 10.And other tasks we decided here.