Setting the traps

The traps should be placed in the afternoon or evening before the regular BFL visit, and checked before carrying out the regular BFL Visit 1 protocol the next day. Alternatively, if you do your BFL visit late in the day, the traps may be placed after carrying out the BFL protocol for Visit 1, and checked the next morning. Two traps should be placed at every site where you are doing the acid rain protocol; one placed 10 paces to the south, and one 10 paces to the north of where you stand to do the regular BFL protocol. If you have a compass you can use it to find the directions. Alternatively, you turn so that the sun is on your left side in the afternoon or on your right side in the morning. The direction you are facing can be used as "north" and the opposite direction as "south." The exact direction isn't what's crucial here; we are specifying the directions to avoid possible bias in the selection of the area within the study site where the traps are placed. The area where the traps are placed should be covered with leaf litter (old decaying leaves and twigs, etc.). If the area is unsuitable because the ground is bare, covered with vegetation (such as grass), or water, the nearest area covered in leaf litter should be used.

To set each trap (when at the correct location), hold the cardboard at an angle of about 45°with one side touching the ground. Slowly pour 1 liter of water across the top surface of the cardboard (the plain side) so that the water wets the entire top surface and runs onto the ground at the bottom edge. Then place the cardboard (wet side down) in the wet area in the leaf litter where the excess water ran off. Weight the cardboard by placing a few sticks or stones on top of it. You might like to mark the top side of the trap with something like "Conservation Study: Please do not remove" to prevent the trap being removed as rubbish by other visitors to the site. Before leaving, record the date and time on your data form. You may also want to mark (or flag) the location of each trap so that they can be found easily.