What is the primary damage caused by wood-staining fungi?

The primary damage caused by wood-staining fungi is discoloration of the wood. This type of fungi affects the appearance of wood by producing pigments that penetrate the cell walls of the wood, resulting in visible color changes ranging from black, blue, green, or brown stains. While these stains may not significantly compromise the structural integrity of the wood, they are undesirable, especially in finished wood products where appearance is essential.

Discoloration can also affect the wood's marketability, as stained wood can be perceived as damaged or lower quality. The presence of staining fungi is indicative of moisture conditions favorable for fungal growth; thus, addressing the moisture issue is crucial for wood preservation.

Structural weakening, increased brittleness, and growth of harmful pests are typically associated with other types of wood decay fungi or conditions rather than staining fungi specifically.