Lead a discussion in why it is important to be involved in the community - like not littering, the importance of helping the elderly, etc. - and how this begins at home and school.
After completing the activity, have the students describe their experience on a Post-it® Note, initial it, and place it on the tree.
Gather the Post-it® Notes and clear the tree each time you assign the choice of a new activity. Keep a list of the activities each student has tried so they're encouraged to branch out.
When the lesson draws to a close, hold a discussion about what the students have accomplished and learned throughout the process.