Red Seal Landscape Horticulturist Practice Exam

What is the role of mycorrhizal fungi in soil health?

1. They prevent soil erosion

2. They form symbiotic relationships with plant roots, enhancing nutrient uptake

3. They decompose organic materials

4. They increase soil acidity

The correct answer is: They form symbiotic relationships with plant roots, enhancing nutrient uptake

Mycorrhizal fungi play a vital role in soil health through their ability to form symbiotic relationships with the roots of most plants. This association is beneficial for both the fungi and the plants. The fungi enhance nutrient uptake, particularly phosphorus and other essential minerals, which are often in forms that plants cannot readily access. This symbiosis allows plants to achieve better growth, promote root development, and improve overall plant health. In addition to aiding in nutrient absorption, mycorrhizal fungi contribute to soil structure by forming networks of hyphae that bind soil particles together. This enhances the soil’s aeration, water retention, and overall resilience against erosion, although this is not their primary role. While mycorrhizal fungi do contribute to soil health indirectly by supporting plant health and soil structure, they do not actively decompose organic materials – that is primarily the role of other organisms like bacteria and saprophytic fungi. Also, mycorrhizal fungi do not inherently increase soil acidity, as their influence on soil pH can be variable depending on various factors, including the type of fungus and the existing soil conditions. Thus, the primary role of mycorrhizal fungi is indeed their partnership with plant roots, which