Leaves that fall into streams accumulate in packs behind branches, rocks, and other obstructions in the stream, forming natural leaf packs. Organic molecules leach out of the leaves, creating a “watershed tea” that flows downstream providing nourishment along the way. On the leaf surface, there is a diverse assemblage of microbes (fungi and bacteria) and macroinvertebrates (insect larvae, crustaceans, etc.) which “process” leaves and facilitate the flow of energy through the stream.
Since the 1970s, Stroud™ Water Research Center scientists have used leaf packs to better understand stream ecosystems from Pennsylvania to Peru and beyond. Conducting a leaf pack experiment by placing artificial leaf packs in the stream replicates the natural process of leaves forming packs in streams. In 2000, the Stroud Center created the Leaf Pack Network®, a global community of teachers, students, and citizen scientists investigating their stream ecosystems. Participants perform a leaf pack experiment to learn scientific principles, gain an understanding of how streams function as ecosystems, and share their data with the world.
We are grateful to individuals and organizations that help us spread the word about the Leaf Pack Network!