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How do saprotrophic fungi decompose wood and other dead materials?

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Two Amanita pantherina mushrooms with brown caps covered in white spots grow among moss and fallen leaves. — fungus A pair of panther cap mushrooms (*Amanita pantherina*). Closely related to the death cap mushroom (*Amanita phalloides*), the panther cap is highly poisonous.

Saprotrophic fungi decompose wood and other dead organic matter through a process known as absorptive nutrition. Because the bulk of plant tissue—including wood—is composed of complex carbohydrates like cellulose, most organisms cannot efficiently metabolize it.1

Fungi overcome this by excreting a specialized suite of enzymes directly onto the substrate. These enzymes break down the complex molecular structures of the dead material into simpler molecules, such as simple carbohydrates*, which the fungi then absorb to fuel their growth.1

This decomposition process is essential for nutrient cycling and the carbon cycle, as it releases carbon dioxide and transforms organic matter into nutrients that other organisms can utilize. For this activity to occur, environmental conditions—specifically moisture, air, and temperature—must be suitable; for example, wood with a moisture content below 20 percent generally inhibits fungal growth. While this process is a vital ecological function, it can also lead to the decay of timber and structural wood, often referred to as wood rot.123