What is the term for partially decomposed material on the forest floor?

• A. Forest litter
• B. Ground duff
• C. Forest duff
• D. Mulch

Answer: (B)

In forest ecosystems, organic matter on the floor goes from fresh litter to a more decomposed layer called duff. Partially decomposed material that sits on or near the soil surface is known as ground duff. This layer is darker and softer than the fresh litter above it and has begun to break down, contributing to soil moisture retention and nutrient release while also shaping the seedbed. Mulch is anything humans place down, not the natural forest layer; forest litter is the fresher, less decomposed material on top, and forest duff is a broader term that isn’t as specific about being in contact with the soil surface. So the best term for the described material is ground duff.