Final answer:
Cedar, juniper, and bald cypress are three types of wood that are naturally resistant to decay and insects. Cedar has high tannin content, which contributes to its durability. Juniper and bald cypress are also durable and sought after for their resistance qualities.
Step-by-step explanation:
Three wood species that are naturally resistant to decay and insects are cedar, juniper, and bald cypress. Cedar wood is high in tannins, which contribute to its durability and resistance to decay. The structure of the cedar tree's water-conducting cells, called tracheids, allows these trees to withstand extreme tensions necessary for water transportation, which also contributes to the wood's resilience.
Juniper wood is also resistant to decay; its durability makes it suitable for fenceposts, and its aromatic quality makes it effective in repelling moths, hence its use in 'cedar chests.' Bald cypress is another species valued for its rot and insect resistance, particularly in the Deep South, although it is more susceptible to fire.
Mahogany is another notable wood known for its exceptional beauty and durability, and while not mentioned explicitly as decay-resistant, it shares similar traits with other valuable timber species that typically have resistance to decay.