As part of a class I teach on preparing elementary science teachers we do an activity called "ecosystem in a bottle." Its a fairly easy activity to set up and provides students with an ongoing project for their science classroom. The activity is consistent with many science and mathematics standards as well as some easily adoptable engineering and technology standards as well. The links before are my students ongoing blog journals for their group's ecosystem (each group consists of 2-3 students). Each group of pre-service teachers have added their own aspects to the journaling and you can see what a great job they are doing in modeling this activity for themselves and, in short time, for their own students use. Perhaps even more interesting....at no time was a textbook used for this activity.
Group 2: http://utscienceclass.blogspot.com/
Group 3: http://livingecosystem.blogspot.com/
Group 4: ecosysteminabottle.wordpress.com
Group 5: http://ecosystembottle.blogspot.com/
Group 6: http://ecosysteminabottlevna.blogspot.com/
Group 7: http://ecosysteminabottlellm.blogspot.com/
Group 8: http://ecosysteminabottle.blogspot.com/
Ecosystem in a Bottle