Rotten Log Lab - Getting Ready
- Find some nice, juicy, moss and mushroom covered, termite and beetle infested logs. You know you’ve found a good log if you can pull off chunks of wood with your hands. I discovered mine (8 logs, enough for my students in groups of 4) in a wooded area of Golden Gate Park. You can use the same log with 2 successive groups of students if you just make sure the first group doesn’t go crazy with the hammer. You can also flip the log over for the second group. I found that the best time to go log hunting is after a month of nice, wet weather after mushrooms have begun to appear.
- Make copies of the Rotten Log Questions
- Cover your tables with newspaper
- Set out logs and the group materials
Optional: Set up protozoa viewing station. I would practice extracting protozoa on your own first. The protozoa are active for around 2 hours before they stop moving so you’ll need to set up a new slide every few hours.
- To extract the protozoa, first find a termite and put it on a glass slide. Use one pair of tweezers to hold its head and the other to hold its rear. Slowly and firmly pull apart. You should see a long, stringy tube, the hindgut. If you don’t squeeze the rear end with the tweezers until you do.
- Place a drop of saline on the hindgut and mash the hindgut with the tweezers or a toothpick. If the hindgut never came out at all, you can mash the entire rear end.
- Cover with a coverslip.
- Observe under the microscope. Look for a mass of writhing stuff. You should be able to zoom in and observe individual protozoa and see differences between the many species that are present.