What is a primary factor required for wood decay fungi to thrive?

Wood decay fungi require excess moisture as a primary factor for thriving because moisture facilitates their growth and reproduction. These fungi decompose wood by breaking down the cellulose and lignin in the cell walls, a process that is significantly accelerated in humid conditions. When wood becomes wet, it creates an ideal environment for fungal spores to germinate and for mycelium to grow, leading to decay.

In contrast, high acidity, direct sunlight, and cold climates do not provide the necessary conditions for wood decay fungi. High acidity levels can inhibit fungal growth rather than support it. Direct sunlight tends to dry out wood surfaces and increase temperatures, which can be unfavorable for fungal survival. Additionally, cold climates typically do not offer the warm, moist conditions that fungi prefer for optimal growth. Thus, the presence of excess moisture is crucial for wood decay fungi to proliferate effectively.