Lightning and Photochemical Fixation - Bolts of lightning and sunlight convert a small amount of atmospheric nitrogen to nitrates. After the air's nitrogen is converted to nitrates, it can then be used to create proteins by plants and animals. Proteins are essential components for cell growth, repair and reproduction. Researchers check forest health by measuring the flow of nitrogen . Decomposers - Decomposers recycle plant and animal wastes back into nitrates so they can be used again.
Researchers measure decomposition in a forest.
They bury net bags with Douglas-fir needles, let them rot for 6 months and then see how much is gone. You can try this experiment at your school.