Which wood property is primarily affected by high moisture levels?

High moisture levels in wood significantly impact its decay resistance. Wood is a hygroscopic material, meaning it absorbs and releases moisture depending on the surrounding environment. When moisture content increases, it creates an ideal environment for biological organisms, such as fungi and bacteria, to thrive. These organisms can cause wood to decay, leading to structural failures and reduced lifespan of the material.

Understanding the relationship between moisture and decay resistance is vital for anyone involved in pest control or wood preservation. Effective management of humidity levels and promoting proper ventilation can help maintain wood's integrity and prolong its useful life by minimizing the risk of decay.

The other properties listed, while they can be influenced by moisture to some extent, do not directly correlate with the decay process as strongly as decay resistance does. Durability may be related to some forms of degradation, but it encompasses a broader range of factors beyond just moisture. Flexibility is more associated with the wood's physical structure, and weight can fluctuate with moisture content but does not reflect the wood's susceptibility to decay.