What are the possible causes of yellow spots on wood and how can they be treated or prevented?

Yellow spots on wood can be caused by various factors such as water damage, mold growth, or chemical reactions. To treat them, you can try sanding the affected area, applying a wood bleach, or using a wood stain to cover the spots. To prevent yellow spots, ensure proper ventilation, avoid exposure to moisture, and use protective coatings on the wood surface.