6th Grade · Science · Activity · shared by Luke Morgan
A free 6th Grade Science activity on forest decomposition. Learn how nature's cleanup crew, like fungi, breaks down wood and recycles nutrients.
🌲 The Science of Decay: Decomposition Factors
How quickly a fallen tree or piece of organic waste breaks down depends on more than just time. It is a chemical and biological process carried out by living decomposers. To understand how these cleanup crews work, read the following information about what controls the speed of rot.
The rate of decay changes based on the surrounding environment. Temperature and moisture are the two most important factors that determine how fast fungi and bacteria can work. In warm climates, higher temperatures provide heat energy that speeds up the chemical reactions inside these organisms. This helps them break down tough plant materials, such as the wood fibers in trees, much faster than in cold regions. When temperatures drop close to freezing, the activity of these decomposers slows down dramatically. This preserves the dead wood and keeps it from rotting for a very long time.
Moisture is another basic need for decay. Fungi need steady moisture to grow their long, thread-like hyphae and to carry the special chemicals called enzymes that they use to dissolve wood. In extremely dry deserts, the lack of water stops these chemical tools from reaching the wood fibers. On the other hand, wood completely buried deep underwater rots very slowly because there is very little oxygen. Decomposers like white-rot fungi need oxygen from the air to carry out oxidation, which is the chemical reaction that breaks wood fibers apart. A healthy balance of warmth, moisture, and air creates the ideal conditions for fast recycling of nutrients.
📋 Student Worksheet: Two Truths and a Lie
Name: _________________________ Date: _____________
Topic: Factors Affecting the Speed of Decomposition