6th Grade · Science · Activity · shared by Luke Morgan
This 6th Grade Science activity explores decomposition and nutrient cycling in forest ecosystems, highlighting the vital role of fungi.
🌲 The Empty Forest Floor: A Science Investigation
Ecologists often study how changes in an environment affect the health of the entire ecosystem. In one recent study, researchers looked at two different sections of a local pine forest over a five-year period. In Section A , the forest was left in its natural state. In Section B , all dead wood, including fallen logs, snapped branches, and old stumps, was removed every month to make the forest look "cleaner."
Read the data and observations collected by the scientists below to understand the impact of removing dead wood from the forest.
📊 Forest Study Data Table (5-Year Totals)
Observation Category
Section A (Natural)
Section B (Wood Removed)
Soil Nutrient Level (Nitrogen/Carbon)
High / Rich
Low / Depleted
New Sapling (Baby Tree) Growth
42 new trees per acre
12 new trees per acre
Insect and Fungi Population
Diverse and abundant
Very few species found
Soil Moisture (After 1 week of no rain)
Damp / Dark
Dry / Dusty
Decaying timber functions as a critical storage place for the essential nutrients a forest ecosystem needs to thrive. It stores vital chemical building blocks, especially carbon and nitrogen. When a tree dies, these nutrients remain trapped inside the tough fibers of the wood. Specialized organisms, including white-rot fungi, use special chemicals called enzymes to break down these sturdy materials. This biological process slowly returns the stored energy and minerals back into the underground soil. Without this constant recycling, the soil quality gets worse and cannot support the healthy growth of new plants.
Furthermore, substantial logs situated on the forest floor operate similarly to biological sponges. They effectively absorb heavy precipitation and distribute it progressively into the surrounding landscape. This…