Joint activities, preferably for Level 3 - 12 (primary - secondary) students in producing a set of leaf fossils (one per student if possible), by using specimen from their own local trees (each fossil represents one tree species). Each fossil should be equipped by a "fossil report" which illustrates all information about the origin tree (in an illustrative narration , created by the student based on their own observation and also from study of literature available to them).
The fossils (including their reports) then ship to the partner school, which then could be used as object of bio-diversity study and put in the class display.